| blob | b89f82b0097b77a786ff8627b02272d2c78d77dd |
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ R E S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 -- Second pass (top-down) type checking and overload resolution procedures
80 -- Typ is the type required by context. These procedures propagate the
81 -- type information recursively to the descendants of N. If the node
82 -- is not overloaded, its Etype is established in the first pass. If
83 -- overloaded, the Resolve routines set the correct type. For arith.
84 -- operators, the Etype is the base type of the context.
86 -- Note that Resolve_Attribute is separated off in Sem_Attr
89 -- Give list of candidate interpretations when a character literal cannot
90 -- be resolved.
93 -- N is a binary operator node which may possibly operate on Boolean
94 -- operands. If the operator does have Boolean operands, then a call is
95 -- made to check the restriction No_Direct_Boolean_Operators.
98 -- Enforce the restrictions on the use of discriminants when constraining
99 -- a component of a discriminated type (record or concurrent type).
102 -- Given a node for an operator associated with type T, check that
103 -- the operator is visible. Operators all of whose operands are
104 -- universal must be checked for visibility during resolution
105 -- because their type is not determinable based on their operands.
108 -- Given a call node, N, which is known to occur immediately within the
109 -- subprogram being called, determines whether it is a detectable case of
110 -- an infinite recursion, and if so, outputs appropriate messages. Returns
111 -- True if an infinite recursion is detected, and False otherwise.
114 -- If the type of the object being initialized uses the secondary stack
115 -- directly or indirectly, create a transient scope for the call to the
116 -- init proc. This is because we do not create transient scopes for the
117 -- initialization of individual components within the init proc itself.
118 -- Could be optimized away perhaps?
121 -- Utility to check whether the name in the call is a predefined
122 -- operator, in which case the call is made into an operator node.
123 -- An instance of an intrinsic conversion operation may be given
124 -- an operator name, but is not treated like an operator.
127 -- If a default expression in entry call N depends on the discriminants
128 -- of the task, it must be replaced with a reference to the discriminant
129 -- of the task being called.
164 function Operator_Kind
167 -- Utility to map the name of an operator into the corresponding Node. Used
168 -- by other node rewriting procedures.
171 -- Resolve actuals of call, and add default expressions for missing ones.
174 -- Called from Resolve_Call, when the prefix denotes an entry or element
175 -- of entry family. Actuals are resolved as for subprograms, and the node
176 -- is rebuilt as an entry call. Also called for protected operations. Typ
177 -- is the context type, which is used when the operation is a protected
178 -- function with no arguments, and the return value is indexed.
181 -- A call to a user-defined intrinsic operator is rewritten as a call
182 -- to the corresponding predefined operator, with suitable conversions.
185 -- Ditto, for unary operators (only arithmetic ones).
188 -- If an operator node resolves to a call to a user-defined operator,
189 -- rewrite the node as a function call.
191 procedure Make_Call_Into_Operator
195 -- Inverse transformation: if an operator is given in functional notation,
196 -- then after resolving the node, transform into an operator node, so
197 -- that operands are resolved properly. Recall that predefined operators
198 -- do not have a full signature and special resolution rules apply.
200 procedure Rewrite_Renamed_Operator
204 -- An operator can rename another, e.g. in an instantiation. In that
205 -- case, the proper operator node must be constructed and resolved.
208 -- The String_Literal_Subtype is built for all strings that are not
209 -- operands of a static concatenation operation. If the argument is
210 -- not a N_String_Literal node, then the call has no effect.
213 -- Build subtype of array type, with the range specified by the slice
216 -- A universal_fixed expression in an universal context is unambiguous
217 -- if there is only one applicable fixed point type. Determining whether
218 -- there is only one requires a search over all visible entities, and
219 -- happens only in very pathological cases (see 6115-006).
221 function Valid_Conversion
225 -- Verify legality rules given in 4.6 (8-23). Target is the target
226 -- type of the conversion, which may be an implicit conversion of
227 -- an actual parameter to an anonymous access type (in which case
228 -- N denotes the actual parameter and N = Operand).
230 -------------------------
231 -- Ambiguous_Character --
232 -------------------------
237 begin
240 Error_Msg_N
255 -------------------------
256 -- Analyze_And_Resolve --
257 -------------------------
260 begin
266 begin
271 -- Version withs check(s) suppressed
273 procedure Analyze_And_Resolve
277 is
280 begin
282 declare
285 begin
291 else
292 declare
295 begin
303 and then Scope_Is_Transient
304 then
305 -- This can only happen if a transient scope was created
306 -- for an inner expression, which will be removed upon
307 -- completion of the analysis of an enclosing construct.
308 -- The transient scope must have the suppress status of
309 -- the enclosing environment, not of this Analyze call.
312 Scope_Suppress;
316 procedure Analyze_And_Resolve
319 is
322 begin
324 declare
327 begin
333 else
334 declare
337 begin
345 and then Scope_Is_Transient
346 then
348 Scope_Suppress;
352 -----------------------------
353 -- Check_Direct_Boolean_Op --
354 -----------------------------
357 begin
363 ----------------------------
364 -- Check_Discriminant_Use --
365 ----------------------------
373 begin
374 -- Any use in a default expression is legal.
381 -- Discriminant cannot be used to constrain a scalar type.
388 then
393 -- The following check catches the unusual case where
394 -- a discriminant appears within an index constraint
395 -- that is part of a larger expression within a constraint
396 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
397 -- For now we only check case of record components, and
398 -- note that a similar check should also apply in the
399 -- case of discriminant constraints below. ???
401 -- Note that the check for N_Subtype_Declaration below is to
402 -- detect the valid use of discriminants in the constraints of a
403 -- subtype declaration when this subtype declaration appears
404 -- inside the scope of a record type (which is syntactically
405 -- illegal, but which may be created as part of derived type
406 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
407 -- for more info.
411 and then not
413 and then
415 or else
418 then
419 Error_Msg_N
424 -- Detect a common beginner error:
426 -- type R (D : Positive := 100) is record
427 -- Name : String (1 .. D);
428 -- end record;
430 -- The default value causes an object of type R to be
431 -- allocated with room for Positive'Last characters.
433 declare
440 -- Return True if type T has a large enough range that
441 -- any array whose index type covered the whole range of
442 -- the type would likely raise Storage_Error.
444 ------------------------
445 -- Large_Storage_Type --
446 ------------------------
449 begin
450 return
451 T = Standard_Integer
452 or else
453 T = Standard_Positive
454 or else
458 begin
459 -- Check that the Disc has a large range
465 -- If the enclosing type is limited, we allocate only the
466 -- default value, not the maximum, and there is no need for
467 -- a warning.
473 -- Check that it is the high bound
477 then
481 -- Check the array allows a large range at this bound.
482 -- First find the array
496 -- Next, find the dimension
504 loop
513 -- Now, check the dimension has a large range
519 -- Warn about the danger
521 Error_Msg_N
531 -- Legal case is in index or discriminant constraint
535 then
537 Error_Msg_N
543 -- Otherwise, context is an expression. It should not be within
544 -- (i.e. a subexpression of) a constraint for a component.
546 else
553 loop
559 -- If the discriminant is used in an expression that is a bound
560 -- of a scalar type, an Itype is created and the bounds are attached
561 -- to its range, not to the original subtype indication. Such use
562 -- is of course a double fault.
565 and then
567 or else
571 -- The constraint itself may be given by a subtype indication,
572 -- rather than by a more common discrete range.
575 and then
579 then
580 Error_Msg_N
586 --------------------------------
587 -- Check_For_Visible_Operator --
588 --------------------------------
591 begin
593 Error_Msg_NE
599 ------------------------------
600 -- Check_Infinite_Recursion --
601 ------------------------------
608 -- Check whether list of actuals is identical to list of formals
609 -- of called function (which is also the enclosing scope).
611 ------------------------
612 -- Same_Argument_List --
613 ------------------------
620 begin
623 else
633 then
644 -- Start of processing for Check_Infinite_Recursion
646 begin
647 -- Loop moving up tree, quitting if something tells us we are
648 -- definitely not in an infinite recursion situation.
651 loop
659 then
664 then
665 -- If the call is the expression of a return statement and
666 -- the actuals are identical to the formals, it's worth a
667 -- warning. However, we skip this if there is an immediately
668 -- preceding raise statement, since the call is never executed.
670 -- Furthermore, this corresponds to a common idiom:
672 -- function F (L : Thing) return Boolean is
673 -- begin
674 -- raise Program_Error;
675 -- return F (L);
676 -- end F;
678 -- for generating a stub function
681 and then Same_Argument_List
682 then
685 and then
687 or else
693 else
704 -------------------------------
705 -- Check_Initialization_Call --
706 -------------------------------
712 -- Check whether the creation of an object of the type will involve
713 -- use of the secondary stack. If T is a record type, this is true
714 -- if the expression for some component uses the secondary stack, eg.
715 -- through a call to a function that returns an unconstrained value.
716 -- False if T is controlled, because cleanups occur elsewhere.
718 -------------
719 -- Uses_SS --
720 -------------
726 begin
740 then
743 -- The expression for a dynamic component may be
744 -- rewritten as a dereference. Retrieve original
745 -- call.
749 then
762 else
767 -- Start of processing for Check_Initialization_Call
769 begin
770 -- Nothing to do if functions do not use the secondary stack for
771 -- returns (i.e. they use a depressed stack pointer instead).
776 -- Otherwise establish a transient scope if the type needs it
783 ------------------------------
784 -- Check_Parameterless_Call --
785 ------------------------------
790 begin
791 -- Defend against junk stuff if errors already detected
798 then
805 -- If the context expects a value, and the name is a procedure,
806 -- this is most likely a missing 'Access. Do not try to resolve
807 -- the parameterless call, error will be caught when the outer
808 -- call is analyzed.
813 and then
817 then
821 -- Rewrite as call if overloadable entity that is (or could be, in
822 -- the overloaded case) a function call. If we know for sure that
823 -- the entity is an enumeration literal, we do not rewrite it.
830 -- Rewrite as call if it is an explicit deference of an expression of
831 -- a subprogram access type, and the suprogram type is not that of a
832 -- procedure or entry.
834 or else
839 -- Rewrite as call if it is a selected component which is a function,
840 -- this is the case of a call to a protected function (which may be
841 -- overloaded with other protected operations).
843 or else
846 or else
848 or else
852 -- If one of the above three conditions is met, rewrite as call.
853 -- Apply the rewriting only once.
855 then
858 then
861 -- If overloaded, overload set belongs to new copy.
865 -- Change node to parameterless function call (note that the
866 -- Parameter_Associations associations field is left set to Empty,
867 -- its normal default value since there are no parameters)
880 ----------------------
881 -- Is_Predefined_Op --
882 ----------------------
885 begin
893 -----------------------------
894 -- Make_Call_Into_Operator --
895 -----------------------------
897 procedure Make_Call_Into_Operator
901 is
916 -- Determine whether E is an access type declared by an access decla-
917 -- ration, and not an (anonymous) allocator type.
920 -- If the operand is not universal, and the operator is given by a
921 -- expanded name, verify that the operand has an interpretation with
922 -- a type defined in the given scope of the operator.
925 -- Find a type of the given class in the package Pack that contains
926 -- the operator.
928 -----------------------------
929 -- Is_Definite_Access_Type --
930 -----------------------------
934 begin
940 ---------------------------
941 -- Operand_Type_In_Scope --
942 ---------------------------
949 begin
953 else
969 ---------------
970 -- Type_In_P --
971 ---------------
977 -- Verify that node is not part of the type declaration for the
978 -- candidate type, which would otherwise be invisible.
980 -------------
981 -- In_Decl --
982 -------------
988 begin
997 else
1000 loop
1003 else
1012 -- Start of processing for Type_In_P
1014 begin
1015 -- If the context type is declared in the prefix package, this
1016 -- is the desired base type.
1020 then
1023 else
1029 and then not In_Decl
1030 then
1041 -- Start of processing for Make_Call_Into_Operator
1043 begin
1046 -- Binary operator
1056 -- Unary operator
1058 else
1064 -- If the operator is denoted by an expanded name, and the prefix is
1065 -- not Standard, but the operator is a predefined one whose scope is
1066 -- Standard, then this is an implicit_operator, inserted as an
1067 -- interpretation by the procedure of the same name. This procedure
1068 -- overestimates the presence of implicit operators, because it does
1069 -- not examine the type of the operands. Verify now that the operand
1070 -- type appears in the given scope. If right operand is universal,
1071 -- check the other operand. In the case of concatenation, either
1072 -- argument can be the component type, so check the type of the result.
1073 -- If both arguments are literals, look for a type of the right kind
1074 -- defined in the given scope. This elaborate nonsense is brought to
1075 -- you courtesy of b33302a. The type itself must be frozen, so we must
1076 -- find the type of the proper class in the given scope.
1078 -- A final wrinkle is the multiplication operator for fixed point
1079 -- types, which is defined in Standard only, and not in the scope of
1080 -- the fixed_point type itself.
1085 -- If the entity being called is defined in the given package,
1086 -- it is a renaming of a predefined operator, and known to be
1087 -- legal.
1091 then
1098 then
1103 else
1112 and then Is_Binary
1114 then
1120 -- Verify that the scope contains a type that corresponds to
1121 -- the given literal. Optimize the case where Pack is Standard.
1143 else
1152 else
1161 then
1164 -- If the type is defined elsewhere, and the operator is not
1165 -- defined in the given scope (by a renaming declaration, e.g.)
1166 -- then this is an error as well. If an extension of System is
1167 -- present, and the type may be defined there, Pack must be
1168 -- System itself.
1175 then
1178 else
1184 then
1191 Error_Msg_NE
1202 else
1206 -- If this is a call to a function that renames a predefined equality,
1207 -- the renaming declaration provides a type that must be used to
1208 -- resolve the operands. This must be done now because resolution of
1209 -- the equality node will not resolve any remaining ambiguity, and it
1210 -- assumes that the first operand is not overloaded.
1215 then
1224 -- If this is an arithmetic operator and the result type is private,
1225 -- the operands and the result must be wrapped in conversion to
1226 -- expose the underlying numeric type and expand the proper checks,
1227 -- e.g. on division.
1231 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1232 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1241 else
1245 -- For predefined operators on literals, the operation freezes
1246 -- their type.
1254 -------------------
1255 -- Operator_Kind --
1256 -------------------
1258 function Operator_Kind
1261 is
1264 begin
1283 else
1287 -- Unary operators
1289 else
1294 else
1302 -----------------------------
1303 -- Pre_Analyze_And_Resolve --
1304 -----------------------------
1309 begin
1313 -- We suppress all checks for this analysis, since the checks will
1314 -- be applied properly, and in the right location, when the default
1315 -- expression is reanalyzed and reexpanded later on.
1319 Expander_Mode_Restore;
1323 -- Version without context type.
1328 begin
1335 Expander_Mode_Restore;
1339 ----------------------------------
1340 -- Replace_Actual_Discriminants --
1341 ----------------------------------
1349 -------------------
1350 -- Process_Discr --
1351 -------------------
1356 begin
1362 then
1378 -- Start of processing for Replace_Actual_Discriminants
1380 begin
1394 else
1399 -------------
1400 -- Resolve --
1401 -------------
1416 -- Try and fix up a literal so that it matches its expected type. New
1417 -- literals are manufactured if necessary to avoid cascaded errors.
1420 -- Called when attempt at resolving current expression fails
1422 --------------------
1423 -- Patch_Up_Value --
1424 --------------------
1427 begin
1430 then
1439 then
1447 then
1458 then
1469 -----------------------
1470 -- Resolution_Failed --
1471 -----------------------
1474 begin
1480 -- The caller will return without calling the expander, so we need
1481 -- to set the analyzed flag. Note that it is fine to set Analyzed
1482 -- to True even if we are in the middle of a shallow analysis,
1483 -- (see the spec of sem for more details) since this is an error
1484 -- situation anyway, and there is no point in repeating the
1485 -- analysis later (indeed it won't work to repeat it later, since
1486 -- we haven't got a clear resolution of which entity is being
1487 -- referenced.)
1493 -- Start of processing for Resolve
1495 begin
1500 -- Access attribute on remote subprogram cannot be used for
1501 -- a non-remote access-to-subprogram type.
1512 then
1513 Error_Msg_N
1517 -- If the context is a Remote_Access_To_Subprogram, access attributes
1518 -- must be resolved with the corresponding fat pointer. There is no need
1519 -- to check for the attribute name since the return type of an
1520 -- attribute is never a remote type.
1526 then
1527 declare
1535 begin
1536 -- Check that Typ is a fat pointer with a reference to a RAS as
1537 -- original access type.
1539 if
1542 or else
1546 then
1547 -- Prefix (N) must statically denote a remote subprogram
1548 -- declared in a package specification.
1565 or else
1567 then
1569 Error_Msg_N
1571 N);
1575 -- If we are generating code for a distributed program.
1576 -- perform semantic checks against the corresponding
1577 -- remote entities.
1582 and then Expander_Active
1583 then
1584 Check_Subtype_Conformant
1586 Old_Id => Designated_Type
1606 then
1611 -- Return if already analyzed
1617 -- Return if type = Any_Type (previous error encountered)
1626 -- If not overloaded, then we know the type, and all that needs doing
1627 -- is to check that this type is compatible with the context.
1633 -- In the overloaded case, we must select the interpretation that
1634 -- is compatible with the context (i.e. the type passed to Resolve)
1636 else
1639 -- Loop through possible interpretations
1643 -- We are only interested in interpretations that are compatible
1644 -- with the expected type, any other interpretations are ignored
1649 Write_Eol;
1652 else
1653 -- First matching interpretation
1661 -- Matching interpretation that is not the first, maybe an
1662 -- error, but there are some cases where preference rules are
1663 -- used to choose between the two possibilities. These and
1664 -- some more obscure cases are handled in Disambiguate.
1666 else
1670 -- Disambiguation has succeeded. Skip the remaining
1671 -- interpretations.
1681 else
1682 -- Before we issue an ambiguity complaint, check for
1683 -- the case of a subprogram call where at least one
1684 -- of the arguments is Any_Type, and if so, suppress
1685 -- the message, since it is a cascaded error.
1689 then
1690 declare
1694 begin
1705 Write_Eol;
1718 then
1723 then
1727 -- Not that special case, so issue message using the
1728 -- flag Ambiguous to control printing of the header
1729 -- message only at the start of an ambiguous set.
1732 Error_Msg_NE
1736 Error_Msg_N
1743 -- By default, the error message refers to the candidate
1744 -- interpretation. But if it is a predefined operator,
1745 -- it is implicitly declared at the declaration of
1746 -- the type of the operand. Recover the sloc of that
1747 -- declaration for the error message.
1753 /= Standard_Standard
1754 then
1759 then
1767 /= Standard_Standard
1768 then
1773 then
1776 else
1783 then
1784 Error_Msg_N
1786 else
1793 -- We have a matching interpretation, Expr_Type is the
1794 -- type from this interpretation, and Seen is the entity.
1796 -- For an operator, just set the entity name. The type will
1797 -- be set by the specific operator resolution routine.
1806 -- For an explicit dereference, attribute reference, range,
1807 -- short-circuit form (which is not an operator node),
1808 -- or a call with a name that is an explicit dereference,
1809 -- there is nothing to be done at this point.
1820 then
1823 -- For procedure or function calls, set the type of the
1824 -- name, and also the entity pointer for the prefix
1830 then
1837 then
1842 -- For all other cases, just set the type of the Name
1844 else
1850 -- Move to next interpretation
1858 -- At this stage Found indicates whether or not an acceptable
1859 -- interpretation exists. If not, then we have an error, except
1860 -- that if the context is Any_Type as a result of some other error,
1861 -- then we suppress the error report.
1866 -- If type we are looking for is Void, then this is the
1867 -- procedure call case, and the error is simply that what
1868 -- we gave is not a procedure name (we think of procedure
1869 -- calls as expressions with types internally, but the user
1870 -- doesn't think of them this way!)
1874 -- Special case message if function used as a procedure
1879 then
1880 Error_Msg_NE
1884 -- Otherwise give general message (not clear what cases
1885 -- this covers, but no harm in providing for them!)
1887 else
1893 -- Otherwise we do have a subexpression with the wrong type
1895 -- Check for the case of an allocator which uses an access
1896 -- type instead of the designated type. This is a common
1897 -- error and we specialize the message, posting an error
1898 -- on the operand of the allocator, complaining that we
1899 -- expected the designated type of the allocator.
1905 then
1909 -- Check for view mismatch on Null in instances, for
1910 -- which the view-swapping mechanism has no identifier.
1916 then
1921 -- Check for an aggregate. Sometimes we can get bogus
1922 -- aggregates from misuse of parentheses, and we are
1923 -- about to complain about the aggregate without even
1924 -- looking inside it.
1926 -- Instead, if we have an aggregate of type Any_Composite,
1927 -- then analyze and resolve the component fields, and then
1928 -- only issue another message if we get no errors doing
1929 -- this (otherwise assume that the errors in the aggregate
1930 -- caused the problem).
1934 then
1935 -- Disable expansion in any case. If there is a type mismatch
1936 -- it may be fatal to try to expand the aggregate. The flag
1937 -- would otherwise be set to false when the error is posted.
1941 declare
1943 -- Check one aggregate, and set Found to True if we
1944 -- have a definite error in any of its elements
1947 -- Check one element of aggregate and set Found to
1948 -- True if we definitely have an error in the element.
1953 begin
1971 ----------------
1972 -- Check_Elmt --
1973 ----------------
1976 begin
1977 -- If we have a nested aggregate, go inside it (to
1978 -- attempt a naked analyze-resolve of the aggregate
1979 -- can cause undesirable cascaded errors). Do not
1980 -- resolve expression if it needs a type from context,
1981 -- as for integer * fixed expression.
1986 else
1991 then
2001 begin
2006 -- If an error message was issued already, Found got reset
2007 -- to True, so if it is still False, issue the standard
2008 -- Wrong_Type message.
2013 then
2014 declare
2016 begin
2022 -- Protected operation: retrieve operation name.
2025 else
2035 declare
2039 begin
2053 else
2056 else
2062 Resolution_Failed;
2065 -- Test if we have more than one interpretation for the context
2068 Resolution_Failed;
2071 -- Here we have an acceptable interpretation for the context
2073 else
2074 -- Propagate type information and normalize tree for various
2075 -- predefined operations. If the context only imposes a class of
2076 -- types, rather than a specific type, propagate the actual type
2077 -- downward.
2084 then
2087 -- Any_Fixed is legal in a real context only if a specific
2088 -- fixed point type is imposed. If Norman Cohen can be
2089 -- confused by this, it deserves a separate message.
2093 then
2100 -- A user-defined operator is tranformed into a function call at
2101 -- this point, so that further processing knows that operators are
2102 -- really operators (i.e. are predefined operators). User-defined
2103 -- operators that are intrinsic are just renamings of the predefined
2104 -- ones, and need not be turned into calls either, but if they rename
2105 -- a different operator, we must transform the node accordingly.
2106 -- Instantiations of Unchecked_Conversion are intrinsic but are
2107 -- treated as functions, even if given an operator designator.
2112 then
2118 and then
2120 = N_Subprogram_Renaming_Declaration
2121 then
2124 -- If the node is rewritten, it will be fully resolved in
2125 -- Rewrite_Renamed_Operator.
2135 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2137 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2139 when N_And_Then | N_Or_Else
2140 => Resolve_Short_Circuit (N, Ctx_Type);
2142 when N_Attribute_Reference
2143 => Resolve_Attribute (N, Ctx_Type);
2145 when N_Character_Literal
2146 => Resolve_Character_Literal (N, Ctx_Type);
2148 when N_Conditional_Expression
2149 => Resolve_Conditional_Expression (N, Ctx_Type);
2151 when N_Expanded_Name
2152 => Resolve_Entity_Name (N, Ctx_Type);
2154 when N_Extension_Aggregate
2155 => Resolve_Extension_Aggregate (N, Ctx_Type);
2157 when N_Explicit_Dereference
2158 => Resolve_Explicit_Dereference (N, Ctx_Type);
2160 when N_Function_Call
2161 => Resolve_Call (N, Ctx_Type);
2163 when N_Identifier
2164 => Resolve_Entity_Name (N, Ctx_Type);
2166 when N_In | N_Not_In
2167 => Resolve_Membership_Op (N, Ctx_Type);
2169 when N_Indexed_Component
2170 => Resolve_Indexed_Component (N, Ctx_Type);
2172 when N_Integer_Literal
2173 => Resolve_Integer_Literal (N, Ctx_Type);
2175 when N_Null => Resolve_Null (N, Ctx_Type);
2177 when N_Op_And | N_Op_Or | N_Op_Xor
2178 => Resolve_Logical_Op (N, Ctx_Type);
2180 when N_Op_Eq | N_Op_Ne
2181 => Resolve_Equality_Op (N, Ctx_Type);
2183 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2184 => Resolve_Comparison_Op (N, Ctx_Type);
2186 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2188 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2189 N_Op_Divide | N_Op_Mod | N_Op_Rem
2191 => Resolve_Arithmetic_Op (N, Ctx_Type);
2193 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2195 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2197 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2198 => Resolve_Unary_Op (N, Ctx_Type);
2200 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2202 when N_Procedure_Call_Statement
2203 => Resolve_Call (N, Ctx_Type);
2205 when N_Operator_Symbol
2206 => Resolve_Operator_Symbol (N, Ctx_Type);
2208 when N_Qualified_Expression
2209 => Resolve_Qualified_Expression (N, Ctx_Type);
2211 when N_Raise_xxx_Error
2212 => Set_Etype (N, Ctx_Type);
2214 when N_Range => Resolve_Range (N, Ctx_Type);
2216 when N_Real_Literal
2217 => Resolve_Real_Literal (N, Ctx_Type);
2219 when N_Reference => Resolve_Reference (N, Ctx_Type);
2221 when N_Selected_Component
2222 => Resolve_Selected_Component (N, Ctx_Type);
2224 when N_Slice => Resolve_Slice (N, Ctx_Type);
2226 when N_String_Literal
2227 => Resolve_String_Literal (N, Ctx_Type);
2229 when N_Subprogram_Info
2230 => Resolve_Subprogram_Info (N, Ctx_Type);
2232 when N_Type_Conversion
2233 => Resolve_Type_Conversion (N, Ctx_Type);
2235 when N_Unchecked_Expression =>
2236 Resolve_Unchecked_Expression (N, Ctx_Type);
2238 when N_Unchecked_Type_Conversion =>
2239 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2241 end case;
2243 -- If the subexpression was replaced by a non-subexpression, then
2244 -- all we do is to expand it. The only legitimate case we know of
2245 -- is converting procedure call statement to entry call statements,
2246 -- but there may be others, so we are making this test general.
2248 if Nkind (N) not in N_Subexpr then
2249 Debug_A_Exit ("resolving ", N, " (done)");
2250 Expand (N);
2251 return;
2252 end if;
2254 -- The expression is definitely NOT overloaded at this point, so
2255 -- we reset the Is_Overloaded flag to avoid any confusion when
2256 -- reanalyzing the node.
2258 Set_Is_Overloaded (N, False);
2260 -- Freeze expression type, entity if it is a name, and designated
2261 -- type if it is an allocator (RM 13.14(10,11,13)).
2263 -- Now that the resolution of the type of the node is complete,
2264 -- and we did not detect an error, we can expand this node. We
2265 -- skip the expand call if we are in a default expression, see
2266 -- section "Handling of Default Expressions" in Sem spec.
2268 Debug_A_Exit ("resolving ", N, " (done)");
2270 -- We unconditionally freeze the expression, even if we are in
2271 -- default expression mode (the Freeze_Expression routine tests
2272 -- this flag and only freezes static types if it is set).
2274 Freeze_Expression (N);
2276 -- Now we can do the expansion
2278 Expand (N);
2279 end if;
2280 end Resolve;
2282 -------------
2283 -- Resolve --
2284 -------------
2286 -- Version with check(s) suppressed
2288 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2289 begin
2290 if Suppress = All_Checks then
2291 declare
2292 Svg : constant Suppress_Array := Scope_Suppress;
2294 begin
2295 Scope_Suppress := (others => True);
2296 Resolve (N, Typ);
2297 Scope_Suppress := Svg;
2298 end;
2300 else
2301 declare
2302 Svg : constant Boolean := Scope_Suppress (Suppress);
2304 begin
2305 Scope_Suppress (Suppress) := True;
2306 Resolve (N, Typ);
2307 Scope_Suppress (Suppress) := Svg;
2308 end;
2309 end if;
2310 end Resolve;
2312 -------------
2313 -- Resolve --
2314 -------------
2316 -- Version with implicit type
2318 procedure Resolve (N : Node_Id) is
2319 begin
2320 Resolve (N, Etype (N));
2321 end Resolve;
2323 ---------------------
2324 -- Resolve_Actuals --
2325 ---------------------
2327 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2328 Loc : constant Source_Ptr := Sloc (N);
2329 A : Node_Id;
2330 F : Entity_Id;
2331 A_Typ : Entity_Id;
2332 F_Typ : Entity_Id;
2333 Prev : Node_Id := Empty;
2335 procedure Insert_Default;
2336 -- If the actual is missing in a call, insert in the actuals list
2337 -- an instance of the default expression. The insertion is always
2338 -- a named association.
2340 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2341 -- Check whether T1 and T2, or their full views, are derived from a
2342 -- common type. Used to enforce the restrictions on array conversions
2343 -- of AI95-00246.
2345 --------------------
2346 -- Insert_Default --
2347 --------------------
2349 procedure Insert_Default is
2350 Actval : Node_Id;
2351 Assoc : Node_Id;
2353 begin
2354 -- Missing argument in call, nothing to insert
2356 if No (Default_Value (F)) then
2357 return;
2359 else
2360 -- Note that we do a full New_Copy_Tree, so that any associated
2361 -- Itypes are properly copied. This may not be needed any more,
2362 -- but it does no harm as a safety measure! Defaults of a generic
2363 -- formal may be out of bounds of the corresponding actual (see
2364 -- cc1311b) and an additional check may be required.
2366 Actval := New_Copy_Tree (Default_Value (F),
2367 New_Scope => Current_Scope, New_Sloc => Loc);
2369 if Is_Concurrent_Type (Scope (Nam))
2370 and then Has_Discriminants (Scope (Nam))
2371 then
2372 Replace_Actual_Discriminants (N, Actval);
2373 end if;
2375 if Is_Overloadable (Nam)
2376 and then Present (Alias (Nam))
2377 then
2378 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2379 and then not Is_Tagged_Type (Etype (F))
2380 then
2381 -- If default is a real literal, do not introduce a
2382 -- conversion whose effect may depend on the run-time
2383 -- size of universal real.
2385 if Nkind (Actval) = N_Real_Literal then
2386 Set_Etype (Actval, Base_Type (Etype (F)));
2387 else
2388 Actval := Unchecked_Convert_To (Etype (F), Actval);
2389 end if;
2390 end if;
2392 if Is_Scalar_Type (Etype (F)) then
2393 Enable_Range_Check (Actval);
2394 end if;
2396 Set_Parent (Actval, N);
2398 -- Resolve aggregates with their base type, to avoid scope
2399 -- anomalies: the subtype was first built in the suprogram
2400 -- declaration, and the current call may be nested.
2402 if Nkind (Actval) = N_Aggregate
2403 and then Has_Discriminants (Etype (Actval))
2404 then
2405 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2406 else
2407 Analyze_And_Resolve (Actval, Etype (Actval));
2408 end if;
2410 else
2411 Set_Parent (Actval, N);
2413 -- See note above concerning aggregates.
2415 if Nkind (Actval) = N_Aggregate
2416 and then Has_Discriminants (Etype (Actval))
2417 then
2418 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2420 -- Resolve entities with their own type, which may differ
2421 -- from the type of a reference in a generic context (the
2422 -- view swapping mechanism did not anticipate the re-analysis
2423 -- of default values in calls).
2425 elsif Is_Entity_Name (Actval) then
2426 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2428 else
2429 Analyze_And_Resolve (Actval, Etype (Actval));
2430 end if;
2431 end if;
2433 -- If default is a tag indeterminate function call, propagate
2434 -- tag to obtain proper dispatching.
2436 if Is_Controlling_Formal (F)
2437 and then Nkind (Default_Value (F)) = N_Function_Call
2438 then
2439 Set_Is_Controlling_Actual (Actval);
2440 end if;
2442 end if;
2444 -- If the default expression raises constraint error, then just
2445 -- silently replace it with an N_Raise_Constraint_Error node,
2446 -- since we already gave the warning on the subprogram spec.
2448 if Raises_Constraint_Error (Actval) then
2449 Rewrite (Actval,
2450 Make_Raise_Constraint_Error (Loc,
2451 Reason => CE_Range_Check_Failed));
2452 Set_Raises_Constraint_Error (Actval);
2453 Set_Etype (Actval, Etype (F));
2454 end if;
2456 Assoc :=
2457 Make_Parameter_Association (Loc,
2458 Explicit_Actual_Parameter => Actval,
2459 Selector_Name => Make_Identifier (Loc, Chars (F)));
2461 -- Case of insertion is first named actual
2463 if No (Prev) or else
2464 Nkind (Parent (Prev)) /= N_Parameter_Association
2465 then
2466 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2467 Set_First_Named_Actual (N, Actval);
2469 if No (Prev) then
2470 if not Present (Parameter_Associations (N)) then
2471 Set_Parameter_Associations (N, New_List (Assoc));
2472 else
2473 Append (Assoc, Parameter_Associations (N));
2474 end if;
2476 else
2477 Insert_After (Prev, Assoc);
2478 end if;
2480 -- Case of insertion is not first named actual
2482 else
2483 Set_Next_Named_Actual
2484 (Assoc, Next_Named_Actual (Parent (Prev)));
2485 Set_Next_Named_Actual (Parent (Prev), Actval);
2486 Append (Assoc, Parameter_Associations (N));
2487 end if;
2489 Mark_Rewrite_Insertion (Assoc);
2490 Mark_Rewrite_Insertion (Actval);
2492 Prev := Actval;
2493 end Insert_Default;
2495 -------------------
2496 -- Same_Ancestor --
2497 -------------------
2499 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2500 FT1 : Entity_Id := T1;
2501 FT2 : Entity_Id := T2;
2503 begin
2504 if Is_Private_Type (T1)
2505 and then Present (Full_View (T1))
2506 then
2507 FT1 := Full_View (T1);
2508 end if;
2510 if Is_Private_Type (T2)
2511 and then Present (Full_View (T2))
2512 then
2513 FT2 := Full_View (T2);
2514 end if;
2516 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
2517 end Same_Ancestor;
2519 -- Start of processing for Resolve_Actuals
2521 begin
2522 A := First_Actual (N);
2523 F := First_Formal (Nam);
2525 while Present (F) loop
2526 if No (A) and then Needs_No_Actuals (Nam) then
2527 null;
2529 -- If we have an error in any actual or formal, indicated by
2530 -- a type of Any_Type, then abandon resolution attempt, and
2531 -- set result type to Any_Type.
2533 elsif (Present (A) and then Etype (A) = Any_Type)
2534 or else Etype (F) = Any_Type
2535 then
2536 Set_Etype (N, Any_Type);
2537 return;
2538 end if;
2540 if Present (A)
2541 and then (Nkind (Parent (A)) /= N_Parameter_Association
2542 or else
2543 Chars (Selector_Name (Parent (A))) = Chars (F))
2544 then
2545 -- If the formal is Out or In_Out, do not resolve and expand the
2546 -- conversion, because it is subsequently expanded into explicit
2547 -- temporaries and assignments. However, the object of the
2548 -- conversion can be resolved. An exception is the case of
2549 -- a tagged type conversion with a class-wide actual. In that
2550 -- case we want the tag check to occur and no temporary will
2551 -- will be needed (no representation change can occur) and
2552 -- the parameter is passed by reference, so we go ahead and
2553 -- resolve the type conversion.
2555 if Ekind (F) /= E_In_Parameter
2556 and then Nkind (A) = N_Type_Conversion
2557 and then not Is_Class_Wide_Type (Etype (Expression (A)))
2558 then
2559 if Ekind (F) = E_In_Out_Parameter
2560 and then Is_Array_Type (Etype (F))
2561 then
2562 if Has_Aliased_Components (Etype (Expression (A)))
2563 /= Has_Aliased_Components (Etype (F))
2564 then
2565 Error_Msg_N
2566 ("both component types in a view conversion must be"
2567 & " aliased, or neither", A);
2569 elsif not Same_Ancestor (Etype (F), Etype (Expression (A)))
2570 and then
2571 (Is_By_Reference_Type (Etype (F))
2572 or else Is_By_Reference_Type (Etype (Expression (A))))
2573 then
2574 Error_Msg_N
2575 ("view conversion between unrelated by_reference "
2577 end if;
2578 end if;
2580 if Conversion_OK (A)
2581 or else Valid_Conversion (A, Etype (A), Expression (A))
2582 then
2583 Resolve (Expression (A));
2584 end if;
2586 else
2587 if Nkind (A) = N_Type_Conversion
2588 and then Is_Array_Type (Etype (F))
2589 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
2590 and then
2591 (Is_Limited_Type (Etype (F))
2592 or else Is_Limited_Type (Etype (Expression (A))))
2593 then
2594 Error_Msg_N
2595 ("Conversion between unrelated limited array types "
2598 -- Disable explanation (which produces additional errors)
2599 -- until AI is approved and warning becomes an error.
2601 -- if Is_Limited_Type (Etype (F)) then
2602 -- Explain_Limited_Type (Etype (F), A);
2603 -- end if;
2605 -- if Is_Limited_Type (Etype (Expression (A))) then
2606 -- Explain_Limited_Type (Etype (Expression (A)), A);
2607 -- end if;
2608 end if;
2610 Resolve (A, Etype (F));
2611 end if;
2613 A_Typ := Etype (A);
2614 F_Typ := Etype (F);
2616 -- Perform error checks for IN and IN OUT parameters
2618 if Ekind (F) /= E_Out_Parameter then
2620 -- Check unset reference. For scalar parameters, it is clearly
2621 -- wrong to pass an uninitialized value as either an IN or
2622 -- IN-OUT parameter. For composites, it is also clearly an
2623 -- error to pass a completely uninitialized value as an IN
2624 -- parameter, but the case of IN OUT is trickier. We prefer
2625 -- not to give a warning here. For example, suppose there is
2626 -- a routine that sets some component of a record to False.
2627 -- It is perfectly reasonable to make this IN-OUT and allow
2628 -- either initialized or uninitialized records to be passed
2629 -- in this case.
2631 -- For partially initialized composite values, we also avoid
2632 -- warnings, since it is quite likely that we are passing a
2633 -- partially initialized value and only the initialized fields
2634 -- will in fact be read in the subprogram.
2636 if Is_Scalar_Type (A_Typ)
2637 or else (Ekind (F) = E_In_Parameter
2638 and then not Is_Partially_Initialized_Type (A_Typ))
2639 then
2640 Check_Unset_Reference (A);
2641 end if;
2643 -- In Ada 83 we cannot pass an OUT parameter as an IN
2644 -- or IN OUT actual to a nested call, since this is a
2645 -- case of reading an out parameter, which is not allowed.
2647 if Ada_Version = Ada_83
2648 and then Is_Entity_Name (A)
2649 and then Ekind (Entity (A)) = E_Out_Parameter
2650 then
2651 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
2652 end if;
2653 end if;
2655 if Ekind (F) /= E_In_Parameter
2656 and then not Is_OK_Variable_For_Out_Formal (A)
2657 then
2658 Error_Msg_NE ("actual for& must be a variable", A, F);
2660 if Is_Entity_Name (A) then
2661 Kill_Checks (Entity (A));
2662 else
2663 Kill_All_Checks;
2664 end if;
2665 end if;
2667 if Etype (A) = Any_Type then
2668 Set_Etype (N, Any_Type);
2669 return;
2670 end if;
2672 -- Apply appropriate range checks for in, out, and in-out
2673 -- parameters. Out and in-out parameters also need a separate
2674 -- check, if there is a type conversion, to make sure the return
2675 -- value meets the constraints of the variable before the
2676 -- conversion.
2678 -- Gigi looks at the check flag and uses the appropriate types.
2679 -- For now since one flag is used there is an optimization which
2680 -- might not be done in the In Out case since Gigi does not do
2681 -- any analysis. More thought required about this ???
2683 if Ekind (F) = E_In_Parameter
2684 or else Ekind (F) = E_In_Out_Parameter
2685 then
2686 if Is_Scalar_Type (Etype (A)) then
2687 Apply_Scalar_Range_Check (A, F_Typ);
2689 elsif Is_Array_Type (Etype (A)) then
2690 Apply_Length_Check (A, F_Typ);
2692 elsif Is_Record_Type (F_Typ)
2693 and then Has_Discriminants (F_Typ)
2694 and then Is_Constrained (F_Typ)
2695 and then (not Is_Derived_Type (F_Typ)
2696 or else Comes_From_Source (Nam))
2697 then
2698 Apply_Discriminant_Check (A, F_Typ);
2700 elsif Is_Access_Type (F_Typ)
2701 and then Is_Array_Type (Designated_Type (F_Typ))
2702 and then Is_Constrained (Designated_Type (F_Typ))
2703 then
2704 Apply_Length_Check (A, F_Typ);
2706 elsif Is_Access_Type (F_Typ)
2707 and then Has_Discriminants (Designated_Type (F_Typ))
2708 and then Is_Constrained (Designated_Type (F_Typ))
2709 then
2710 Apply_Discriminant_Check (A, F_Typ);
2712 else
2713 Apply_Range_Check (A, F_Typ);
2714 end if;
2716 -- Ada 2005 (AI-231)
2718 if Ada_Version >= Ada_05
2719 and then Is_Access_Type (F_Typ)
2720 and then (Can_Never_Be_Null (F)
2721 or else Can_Never_Be_Null (F_Typ))
2722 then
2723 if Nkind (A) = N_Null then
2724 Error_Msg_NE
2725 ("(Ada 2005) not allowed for " &
2726 "null-exclusion formal", A, F_Typ);
2727 end if;
2728 end if;
2729 end if;
2731 if Ekind (F) = E_Out_Parameter
2732 or else Ekind (F) = E_In_Out_Parameter
2733 then
2734 if Nkind (A) = N_Type_Conversion then
2735 if Is_Scalar_Type (A_Typ) then
2736 Apply_Scalar_Range_Check
2737 (Expression (A), Etype (Expression (A)), A_Typ);
2738 else
2739 Apply_Range_Check
2740 (Expression (A), Etype (Expression (A)), A_Typ);
2741 end if;
2743 else
2744 if Is_Scalar_Type (F_Typ) then
2745 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
2747 elsif Is_Array_Type (F_Typ)
2748 and then Ekind (F) = E_Out_Parameter
2749 then
2750 Apply_Length_Check (A, F_Typ);
2752 else
2753 Apply_Range_Check (A, A_Typ, F_Typ);
2754 end if;
2755 end if;
2756 end if;
2758 -- An actual associated with an access parameter is implicitly
2759 -- converted to the anonymous access type of the formal and
2760 -- must satisfy the legality checks for access conversions.
2762 if Ekind (F_Typ) = E_Anonymous_Access_Type then
2763 if not Valid_Conversion (A, F_Typ, A) then
2764 Error_Msg_N
2765 ("invalid implicit conversion for access parameter", A);
2766 end if;
2767 end if;
2769 -- Check bad case of atomic/volatile argument (RM C.6(12))
2771 if Is_By_Reference_Type (Etype (F))
2772 and then Comes_From_Source (N)
2773 then
2774 if Is_Atomic_Object (A)
2775 and then not Is_Atomic (Etype (F))
2776 then
2777 Error_Msg_N
2778 ("cannot pass atomic argument to non-atomic formal",
2779 N);
2781 elsif Is_Volatile_Object (A)
2782 and then not Is_Volatile (Etype (F))
2783 then
2784 Error_Msg_N
2785 ("cannot pass volatile argument to non-volatile formal",
2786 N);
2787 end if;
2788 end if;
2790 -- Check that subprograms don't have improper controlling
2791 -- arguments (RM 3.9.2 (9))
2793 if Is_Controlling_Formal (F) then
2794 Set_Is_Controlling_Actual (A);
2795 elsif Nkind (A) = N_Explicit_Dereference then
2796 Validate_Remote_Access_To_Class_Wide_Type (A);
2797 end if;
2799 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
2800 and then not Is_Class_Wide_Type (F_Typ)
2801 and then not Is_Controlling_Formal (F)
2802 then
2803 Error_Msg_N ("class-wide argument not allowed here!", A);
2805 if Is_Subprogram (Nam)
2806 and then Comes_From_Source (Nam)
2807 then
2808 Error_Msg_Node_2 := F_Typ;
2809 Error_Msg_NE
2810 ("& is not a primitive operation of &!", A, Nam);
2811 end if;
2813 elsif Is_Access_Type (A_Typ)
2814 and then Is_Access_Type (F_Typ)
2815 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
2816 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
2817 or else (Nkind (A) = N_Attribute_Reference
2818 and then
2819 Is_Class_Wide_Type (Etype (Prefix (A)))))
2820 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
2821 and then not Is_Controlling_Formal (F)
2822 then
2823 Error_Msg_N
2824 ("access to class-wide argument not allowed here!", A);
2826 if Is_Subprogram (Nam)
2827 and then Comes_From_Source (Nam)
2828 then
2829 Error_Msg_Node_2 := Designated_Type (F_Typ);
2830 Error_Msg_NE
2831 ("& is not a primitive operation of &!", A, Nam);
2832 end if;
2833 end if;
2835 Eval_Actual (A);
2837 -- If it is a named association, treat the selector_name as
2838 -- a proper identifier, and mark the corresponding entity.
2840 if Nkind (Parent (A)) = N_Parameter_Association then
2841 Set_Entity (Selector_Name (Parent (A)), F);
2842 Generate_Reference (F, Selector_Name (Parent (A)));
2843 Set_Etype (Selector_Name (Parent (A)), F_Typ);
2845 end if;
2847 Prev := A;
2849 if Ekind (F) /= E_Out_Parameter then
2850 Check_Unset_Reference (A);
2851 end if;
2853 Next_Actual (A);
2855 -- Case where actual is not present
2857 else
2858 Insert_Default;
2859 end if;
2861 Next_Formal (F);
2862 end loop;
2863 end Resolve_Actuals;
2865 -----------------------
2866 -- Resolve_Allocator --
2867 -----------------------
2869 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
2870 E : constant Node_Id := Expression (N);
2871 Subtyp : Entity_Id;
2872 Discrim : Entity_Id;
2873 Constr : Node_Id;
2874 Disc_Exp : Node_Id;
2876 function In_Dispatching_Context return Boolean;
2877 -- If the allocator is an actual in a call, it is allowed to be
2878 -- class-wide when the context is not because it is a controlling
2879 -- actual.
2881 ----------------------------
2882 -- In_Dispatching_Context --
2883 ----------------------------
2885 function In_Dispatching_Context return Boolean is
2886 Par : constant Node_Id := Parent (N);
2888 begin
2889 return (Nkind (Par) = N_Function_Call
2890 or else Nkind (Par) = N_Procedure_Call_Statement)
2891 and then Is_Entity_Name (Name (Par))
2892 and then Is_Dispatching_Operation (Entity (Name (Par)));
2893 end In_Dispatching_Context;
2895 -- Start of processing for Resolve_Allocator
2897 begin
2898 -- Replace general access with specific type
2900 if Ekind (Etype (N)) = E_Allocator_Type then
2901 Set_Etype (N, Base_Type (Typ));
2902 end if;
2904 if Is_Abstract (Typ) then
2905 Error_Msg_N ("type of allocator cannot be abstract", N);
2906 end if;
2908 -- For qualified expression, resolve the expression using the
2909 -- given subtype (nothing to do for type mark, subtype indication)
2911 if Nkind (E) = N_Qualified_Expression then
2912 if Is_Class_Wide_Type (Etype (E))
2913 and then not Is_Class_Wide_Type (Designated_Type (Typ))
2914 and then not In_Dispatching_Context
2915 then
2916 Error_Msg_N
2917 ("class-wide allocator not allowed for this access type", N);
2918 end if;
2920 Resolve (Expression (E), Etype (E));
2921 Check_Unset_Reference (Expression (E));
2923 -- A qualified expression requires an exact match of the type,
2924 -- class-wide matching is not allowed.
2926 if (Is_Class_Wide_Type (Etype (Expression (E)))
2927 or else Is_Class_Wide_Type (Etype (E)))
2928 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
2929 then
2930 Wrong_Type (Expression (E), Etype (E));
2931 end if;
2933 -- For a subtype mark or subtype indication, freeze the subtype
2935 else
2936 Freeze_Expression (E);
2938 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
2939 Error_Msg_N
2940 ("initialization required for access-to-constant allocator", N);
2941 end if;
2943 -- A special accessibility check is needed for allocators that
2944 -- constrain access discriminants. The level of the type of the
2945 -- expression used to contrain an access discriminant cannot be
2946 -- deeper than the type of the allocator (in constrast to access
2947 -- parameters, where the level of the actual can be arbitrary).
2948 -- We can't use Valid_Conversion to perform this check because
2949 -- in general the type of the allocator is unrelated to the type
2950 -- of the access discriminant. Note that specialized checks are
2951 -- needed for the cases of a constraint expression which is an
2952 -- access attribute or an access discriminant.
2954 if Nkind (Original_Node (E)) = N_Subtype_Indication
2955 and then Ekind (Typ) /= E_Anonymous_Access_Type
2956 then
2957 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
2959 if Has_Discriminants (Subtyp) then
2960 Discrim := First_Discriminant (Base_Type (Subtyp));
2961 Constr := First (Constraints (Constraint (Original_Node (E))));
2963 while Present (Discrim) and then Present (Constr) loop
2964 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
2965 if Nkind (Constr) = N_Discriminant_Association then
2966 Disc_Exp := Original_Node (Expression (Constr));
2967 else
2968 Disc_Exp := Original_Node (Constr);
2969 end if;
2971 if Type_Access_Level (Etype (Disc_Exp))
2972 > Type_Access_Level (Typ)
2973 then
2974 Error_Msg_N
2975 ("operand type has deeper level than allocator type",
2976 Disc_Exp);
2978 elsif Nkind (Disc_Exp) = N_Attribute_Reference
2979 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
2980 = Attribute_Access
2981 and then Object_Access_Level (Prefix (Disc_Exp))
2982 > Type_Access_Level (Typ)
2983 then
2984 Error_Msg_N
2985 ("prefix of attribute has deeper level than"
2986 & " allocator type", Disc_Exp);
2988 -- When the operand is an access discriminant the check
2989 -- is against the level of the prefix object.
2991 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
2992 and then Nkind (Disc_Exp) = N_Selected_Component
2993 and then Object_Access_Level (Prefix (Disc_Exp))
2994 > Type_Access_Level (Typ)
2995 then
2996 Error_Msg_N
2997 ("access discriminant has deeper level than"
2998 & " allocator type", Disc_Exp);
2999 end if;
3000 end if;
3001 Next_Discriminant (Discrim);
3002 Next (Constr);
3003 end loop;
3004 end if;
3005 end if;
3006 end if;
3008 -- Check for allocation from an empty storage pool
3010 if No_Pool_Assigned (Typ) then
3011 declare
3012 Loc : constant Source_Ptr := Sloc (N);
3014 begin
3015 Error_Msg_N ("?allocation from empty storage pool!", N);
3016 Error_Msg_N ("?Storage_Error will be raised at run time!", N);
3017 Insert_Action (N,
3018 Make_Raise_Storage_Error (Loc,
3019 Reason => SE_Empty_Storage_Pool));
3020 end;
3021 end if;
3022 end Resolve_Allocator;
3024 ---------------------------
3025 -- Resolve_Arithmetic_Op --
3026 ---------------------------
3028 -- Used for resolving all arithmetic operators except exponentiation
3030 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
3031 L : constant Node_Id := Left_Opnd (N);
3032 R : constant Node_Id := Right_Opnd (N);
3033 TL : constant Entity_Id := Base_Type (Etype (L));
3034 TR : constant Entity_Id := Base_Type (Etype (R));
3035 T : Entity_Id;
3036 Rop : Node_Id;
3038 B_Typ : constant Entity_Id := Base_Type (Typ);
3039 -- We do the resolution using the base type, because intermediate values
3040 -- in expressions always are of the base type, not a subtype of it.
3042 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
3043 -- Return True iff given type is Integer or universal real/integer
3045 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
3046 -- Choose type of integer literal in fixed-point operation to conform
3047 -- to available fixed-point type. T is the type of the other operand,
3048 -- which is needed to determine the expected type of N.
3050 procedure Set_Operand_Type (N : Node_Id);
3051 -- Set operand type to T if universal
3053 -----------------------------
3054 -- Is_Integer_Or_Universal --
3055 -----------------------------
3057 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
3058 T : Entity_Id;
3059 Index : Interp_Index;
3060 It : Interp;
3062 begin
3063 if not Is_Overloaded (N) then
3064 T := Etype (N);
3065 return Base_Type (T) = Base_Type (Standard_Integer)
3066 or else T = Universal_Integer
3067 or else T = Universal_Real;
3068 else
3069 Get_First_Interp (N, Index, It);
3071 while Present (It.Typ) loop
3073 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
3074 or else It.Typ = Universal_Integer
3075 or else It.Typ = Universal_Real
3076 then
3077 return True;
3078 end if;
3080 Get_Next_Interp (Index, It);
3081 end loop;
3082 end if;
3084 return False;
3085 end Is_Integer_Or_Universal;
3087 ----------------------------
3088 -- Set_Mixed_Mode_Operand --
3089 ----------------------------
3091 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
3092 Index : Interp_Index;
3093 It : Interp;
3095 begin
3096 if Universal_Interpretation (N) = Universal_Integer then
3098 -- A universal integer literal is resolved as standard integer
3099 -- except in the case of a fixed-point result, where we leave
3100 -- it as universal (to be handled by Exp_Fixd later on)
3102 if Is_Fixed_Point_Type (T) then
3103 Resolve (N, Universal_Integer);
3104 else
3105 Resolve (N, Standard_Integer);
3106 end if;
3108 elsif Universal_Interpretation (N) = Universal_Real
3109 and then (T = Base_Type (Standard_Integer)
3110 or else T = Universal_Integer
3111 or else T = Universal_Real)
3112 then
3113 -- A universal real can appear in a fixed-type context. We resolve
3114 -- the literal with that context, even though this might raise an
3115 -- exception prematurely (the other operand may be zero).
3117 Resolve (N, B_Typ);
3119 elsif Etype (N) = Base_Type (Standard_Integer)
3120 and then T = Universal_Real
3121 and then Is_Overloaded (N)
3122 then
3123 -- Integer arg in mixed-mode operation. Resolve with universal
3124 -- type, in case preference rule must be applied.
3126 Resolve (N, Universal_Integer);
3128 elsif Etype (N) = T
3129 and then B_Typ /= Universal_Fixed
3130 then
3131 -- Not a mixed-mode operation. Resolve with context.
3133 Resolve (N, B_Typ);
3135 elsif Etype (N) = Any_Fixed then
3137 -- N may itself be a mixed-mode operation, so use context type.
3139 Resolve (N, B_Typ);
3141 elsif Is_Fixed_Point_Type (T)
3142 and then B_Typ = Universal_Fixed
3143 and then Is_Overloaded (N)
3144 then
3145 -- Must be (fixed * fixed) operation, operand must have one
3146 -- compatible interpretation.
3148 Resolve (N, Any_Fixed);
3150 elsif Is_Fixed_Point_Type (B_Typ)
3151 and then (T = Universal_Real
3152 or else Is_Fixed_Point_Type (T))
3153 and then Is_Overloaded (N)
3154 then
3155 -- C * F(X) in a fixed context, where C is a real literal or a
3156 -- fixed-point expression. F must have either a fixed type
3157 -- interpretation or an integer interpretation, but not both.
3159 Get_First_Interp (N, Index, It);
3161 while Present (It.Typ) loop
3162 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
3164 if Analyzed (N) then
3165 Error_Msg_N ("ambiguous operand in fixed operation", N);
3166 else
3167 Resolve (N, Standard_Integer);
3168 end if;
3170 elsif Is_Fixed_Point_Type (It.Typ) then
3172 if Analyzed (N) then
3173 Error_Msg_N ("ambiguous operand in fixed operation", N);
3174 else
3175 Resolve (N, It.Typ);
3176 end if;
3177 end if;
3179 Get_Next_Interp (Index, It);
3180 end loop;
3182 -- Reanalyze the literal with the fixed type of the context.
3183 -- If context is Universal_Fixed, we are within a conversion,
3184 -- leave the literal as a universal real because there is no
3185 -- usable fixed type, and the target of the conversion plays
3186 -- no role in the resolution.
3188 declare
3189 Op2 : Node_Id;
3190 T2 : Entity_Id;
3192 begin
3193 if N = L then
3194 Op2 := R;
3195 else
3196 Op2 := L;
3197 end if;
3199 if B_Typ = Universal_Fixed
3200 and then Nkind (Op2) = N_Real_Literal
3201 then
3202 T2 := Universal_Real;
3203 else
3204 T2 := B_Typ;
3205 end if;
3207 Set_Analyzed (Op2, False);
3208 Resolve (Op2, T2);
3209 end;
3211 else
3212 Resolve (N);
3213 end if;
3214 end Set_Mixed_Mode_Operand;
3216 ----------------------
3217 -- Set_Operand_Type --
3218 ----------------------
3220 procedure Set_Operand_Type (N : Node_Id) is
3221 begin
3222 if Etype (N) = Universal_Integer
3223 or else Etype (N) = Universal_Real
3224 then
3225 Set_Etype (N, T);
3226 end if;
3227 end Set_Operand_Type;
3229 -- Start of processing for Resolve_Arithmetic_Op
3231 begin
3232 if Comes_From_Source (N)
3233 and then Ekind (Entity (N)) = E_Function
3234 and then Is_Imported (Entity (N))
3235 and then Is_Intrinsic_Subprogram (Entity (N))
3236 then
3237 Resolve_Intrinsic_Operator (N, Typ);
3238 return;
3240 -- Special-case for mixed-mode universal expressions or fixed point
3241 -- type operation: each argument is resolved separately. The same
3242 -- treatment is required if one of the operands of a fixed point
3243 -- operation is universal real, since in this case we don't do a
3244 -- conversion to a specific fixed-point type (instead the expander
3245 -- takes care of the case).
3247 elsif (B_Typ = Universal_Integer
3248 or else B_Typ = Universal_Real)
3249 and then Present (Universal_Interpretation (L))
3250 and then Present (Universal_Interpretation (R))
3251 then
3252 Resolve (L, Universal_Interpretation (L));
3253 Resolve (R, Universal_Interpretation (R));
3254 Set_Etype (N, B_Typ);
3256 elsif (B_Typ = Universal_Real
3257 or else Etype (N) = Universal_Fixed
3258 or else (Etype (N) = Any_Fixed
3259 and then Is_Fixed_Point_Type (B_Typ))
3260 or else (Is_Fixed_Point_Type (B_Typ)
3261 and then (Is_Integer_Or_Universal (L)
3262 or else
3263 Is_Integer_Or_Universal (R))))
3264 and then (Nkind (N) = N_Op_Multiply or else
3265 Nkind (N) = N_Op_Divide)
3266 then
3267 if TL = Universal_Integer or else TR = Universal_Integer then
3268 Check_For_Visible_Operator (N, B_Typ);
3269 end if;
3271 -- If context is a fixed type and one operand is integer, the
3272 -- other is resolved with the type of the context.
3274 if Is_Fixed_Point_Type (B_Typ)
3275 and then (Base_Type (TL) = Base_Type (Standard_Integer)
3276 or else TL = Universal_Integer)
3277 then
3278 Resolve (R, B_Typ);
3279 Resolve (L, TL);
3281 elsif Is_Fixed_Point_Type (B_Typ)
3282 and then (Base_Type (TR) = Base_Type (Standard_Integer)
3283 or else TR = Universal_Integer)
3284 then
3285 Resolve (L, B_Typ);
3286 Resolve (R, TR);
3288 else
3289 Set_Mixed_Mode_Operand (L, TR);
3290 Set_Mixed_Mode_Operand (R, TL);
3291 end if;
3293 if Etype (N) = Universal_Fixed
3294 or else Etype (N) = Any_Fixed
3295 then
3296 if B_Typ = Universal_Fixed
3297 and then Nkind (Parent (N)) /= N_Type_Conversion
3298 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3299 then
3300 Error_Msg_N
3301 ("type cannot be determined from context!", N);
3302 Error_Msg_N
3305 Set_Etype (L, Any_Type);
3306 Set_Etype (R, Any_Type);
3308 else
3309 if Ada_Version = Ada_83
3310 and then Etype (N) = Universal_Fixed
3311 and then Nkind (Parent (N)) /= N_Type_Conversion
3312 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3313 then
3314 Error_Msg_N
3315 ("(Ada 83) fixed-point operation " &
3316 "needs explicit conversion",
3317 N);
3318 end if;
3320 Set_Etype (N, B_Typ);
3321 end if;
3323 elsif Is_Fixed_Point_Type (B_Typ)
3324 and then (Is_Integer_Or_Universal (L)
3325 or else Nkind (L) = N_Real_Literal
3326 or else Nkind (R) = N_Real_Literal
3327 or else
3328 Is_Integer_Or_Universal (R))
3329 then
3330 Set_Etype (N, B_Typ);
3332 elsif Etype (N) = Any_Fixed then
3334 -- If no previous errors, this is only possible if one operand
3335 -- is overloaded and the context is universal. Resolve as such.
3337 Set_Etype (N, B_Typ);
3338 end if;
3340 else
3341 if (TL = Universal_Integer or else TL = Universal_Real)
3342 and then (TR = Universal_Integer or else TR = Universal_Real)
3343 then
3344 Check_For_Visible_Operator (N, B_Typ);
3345 end if;
3347 -- If the context is Universal_Fixed and the operands are also
3348 -- universal fixed, this is an error, unless there is only one
3349 -- applicable fixed_point type (usually duration).
3351 if B_Typ = Universal_Fixed
3352 and then Etype (L) = Universal_Fixed
3353 then
3354 T := Unique_Fixed_Point_Type (N);
3356 if T = Any_Type then
3357 Set_Etype (N, T);
3358 return;
3359 else
3360 Resolve (L, T);
3361 Resolve (R, T);
3362 end if;
3364 else
3365 Resolve (L, B_Typ);
3366 Resolve (R, B_Typ);
3367 end if;
3369 -- If one of the arguments was resolved to a non-universal type.
3370 -- label the result of the operation itself with the same type.
3371 -- Do the same for the universal argument, if any.
3373 T := Intersect_Types (L, R);
3374 Set_Etype (N, Base_Type (T));
3375 Set_Operand_Type (L);
3376 Set_Operand_Type (R);
3377 end if;
3379 Generate_Operator_Reference (N, Typ);
3380 Eval_Arithmetic_Op (N);
3382 -- Set overflow and division checking bit. Much cleverer code needed
3383 -- here eventually and perhaps the Resolve routines should be separated
3384 -- for the various arithmetic operations, since they will need
3385 -- different processing. ???
3387 if Nkind (N) in N_Op then
3388 if not Overflow_Checks_Suppressed (Etype (N)) then
3389 Enable_Overflow_Check (N);
3390 end if;
3392 -- Give warning if explicit division by zero
3394 if (Nkind (N) = N_Op_Divide
3395 or else Nkind (N) = N_Op_Rem
3396 or else Nkind (N) = N_Op_Mod)
3397 and then not Division_Checks_Suppressed (Etype (N))
3398 then
3399 Rop := Right_Opnd (N);
3401 if Compile_Time_Known_Value (Rop)
3402 and then ((Is_Integer_Type (Etype (Rop))
3403 and then Expr_Value (Rop) = Uint_0)
3404 or else
3405 (Is_Real_Type (Etype (Rop))
3406 and then Expr_Value_R (Rop) = Ureal_0))
3407 then
3408 Apply_Compile_Time_Constraint_Error
3409 (N, "division by zero?", CE_Divide_By_Zero,
3410 Loc => Sloc (Right_Opnd (N)));
3412 -- Otherwise just set the flag to check at run time
3414 else
3415 Set_Do_Division_Check (N);
3416 end if;
3417 end if;
3418 end if;
3420 Check_Unset_Reference (L);
3421 Check_Unset_Reference (R);
3422 end Resolve_Arithmetic_Op;
3424 ------------------
3425 -- Resolve_Call --
3426 ------------------
3428 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
3429 Loc : constant Source_Ptr := Sloc (N);
3430 Subp : constant Node_Id := Name (N);
3431 Nam : Entity_Id;
3432 I : Interp_Index;
3433 It : Interp;
3434 Norm_OK : Boolean;
3435 Scop : Entity_Id;
3436 Decl : Node_Id;
3438 begin
3439 -- The context imposes a unique interpretation with type Typ on
3440 -- a procedure or function call. Find the entity of the subprogram
3441 -- that yields the expected type, and propagate the corresponding
3442 -- formal constraints on the actuals. The caller has established
3443 -- that an interpretation exists, and emitted an error if not unique.
3445 -- First deal with the case of a call to an access-to-subprogram,
3446 -- dereference made explicit in Analyze_Call.
3448 if Ekind (Etype (Subp)) = E_Subprogram_Type then
3449 if not Is_Overloaded (Subp) then
3450 Nam := Etype (Subp);
3452 else
3453 -- Find the interpretation whose type (a subprogram type)
3454 -- has a return type that is compatible with the context.
3455 -- Analysis of the node has established that one exists.
3457 Get_First_Interp (Subp, I, It);
3458 Nam := Empty;
3460 while Present (It.Typ) loop
3461 if Covers (Typ, Etype (It.Typ)) then
3462 Nam := It.Typ;
3463 exit;
3464 end if;
3466 Get_Next_Interp (I, It);
3467 end loop;
3469 if No (Nam) then
3470 raise Program_Error;
3471 end if;
3472 end if;
3474 -- If the prefix is not an entity, then resolve it
3476 if not Is_Entity_Name (Subp) then
3477 Resolve (Subp, Nam);
3478 end if;
3480 -- For an indirect call, we always invalidate checks, since we
3481 -- do not know whether the subprogram is local or global. Yes
3482 -- we could do better here, e.g. by knowing that there are no
3483 -- local subprograms, but it does not seem worth the effort.
3484 -- Similarly, we kill al knowledge of current constant values.
3486 Kill_Current_Values;
3488 -- If this is a procedure call which is really an entry call, do
3489 -- the conversion of the procedure call to an entry call. Protected
3490 -- operations use the same circuitry because the name in the call
3491 -- can be an arbitrary expression with special resolution rules.
3493 elsif Nkind (Subp) = N_Selected_Component
3494 or else Nkind (Subp) = N_Indexed_Component
3495 or else (Is_Entity_Name (Subp)
3496 and then Ekind (Entity (Subp)) = E_Entry)
3497 then
3498 Resolve_Entry_Call (N, Typ);
3499 Check_Elab_Call (N);
3501 -- Kill checks and constant values, as above for indirect case
3502 -- Who knows what happens when another task is activated?
3504 Kill_Current_Values;
3505 return;
3507 -- Normal subprogram call with name established in Resolve
3509 elsif not (Is_Type (Entity (Subp))) then
3510 Nam := Entity (Subp);
3511 Set_Entity_With_Style_Check (Subp, Nam);
3512 Generate_Reference (Nam, Subp);
3514 -- Otherwise we must have the case of an overloaded call
3516 else
3517 pragma Assert (Is_Overloaded (Subp));
3518 Nam := Empty; -- We know that it will be assigned in loop below.
3520 Get_First_Interp (Subp, I, It);
3522 while Present (It.Typ) loop
3523 if Covers (Typ, It.Typ) then
3524 Nam := It.Nam;
3525 Set_Entity_With_Style_Check (Subp, Nam);
3526 Generate_Reference (Nam, Subp);
3527 exit;
3528 end if;
3530 Get_Next_Interp (I, It);
3531 end loop;
3532 end if;
3534 -- Check that a call to Current_Task does not occur in an entry body
3536 if Is_RTE (Nam, RE_Current_Task) then
3537 declare
3538 P : Node_Id;
3540 begin
3541 P := N;
3542 loop
3543 P := Parent (P);
3544 exit when No (P);
3546 if Nkind (P) = N_Entry_Body then
3547 Error_Msg_NE
3549 N, Nam);
3550 exit;
3551 end if;
3552 end loop;
3553 end;
3554 end if;
3556 -- Cannot call thread body directly
3558 if Is_Thread_Body (Nam) then
3560 end if;
3562 -- If the subprogram is not global, then kill all checks. This is
3563 -- a bit conservative, since in many cases we could do better, but
3564 -- it is not worth the effort. Similarly, we kill constant values.
3565 -- However we do not need to do this for internal entities (unless
3566 -- they are inherited user-defined subprograms), since they are not
3567 -- in the business of molesting global values.
3569 if not Is_Library_Level_Entity (Nam)
3570 and then (Comes_From_Source (Nam)
3571 or else (Present (Alias (Nam))
3572 and then Comes_From_Source (Alias (Nam))))
3573 then
3574 Kill_Current_Values;
3575 end if;
3577 -- Check for call to obsolescent subprogram
3579 if Warn_On_Obsolescent_Feature then
3580 Decl := Parent (Parent (Nam));
3582 if Nkind (Decl) = N_Subprogram_Declaration
3583 and then Is_List_Member (Decl)
3584 and then Nkind (Next (Decl)) = N_Pragma
3585 then
3586 declare
3587 P : constant Node_Id := Next (Decl);
3589 begin
3590 if Chars (P) = Name_Obsolescent then
3593 if Pragma_Argument_Associations (P) /= No_List then
3594 Name_Buffer (1) := '|';
3595 Name_Buffer (2) := '?';
3596 Name_Len := 2;
3597 Add_String_To_Name_Buffer
3598 (Strval (Expression
3599 (First (Pragma_Argument_Associations (P)))));
3600 Error_Msg_N (Name_Buffer (1 .. Name_Len), N);
3601 end if;
3602 end if;
3603 end;
3604 end if;
3605 end if;
3607 -- Check that a procedure call does not occur in the context
3608 -- of the entry call statement of a conditional or timed
3609 -- entry call. Note that the case of a call to a subprogram
3610 -- renaming of an entry will also be rejected. The test
3611 -- for N not being an N_Entry_Call_Statement is defensive,
3612 -- covering the possibility that the processing of entry
3613 -- calls might reach this point due to later modifications
3614 -- of the code above.
3616 if Nkind (Parent (N)) = N_Entry_Call_Alternative
3617 and then Nkind (N) /= N_Entry_Call_Statement
3618 and then Entry_Call_Statement (Parent (N)) = N
3619 then
3621 end if;
3623 -- Check that this is not a call to a protected procedure or
3624 -- entry from within a protected function.
3626 if Ekind (Current_Scope) = E_Function
3627 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
3628 and then Ekind (Nam) /= E_Function
3629 and then Scope (Nam) = Scope (Current_Scope)
3630 then
3634 end if;
3636 -- Freeze the subprogram name if not in default expression. Note
3637 -- that we freeze procedure calls as well as function calls.
3638 -- Procedure calls are not frozen according to the rules (RM
3639 -- 13.14(14)) because it is impossible to have a procedure call to
3640 -- a non-frozen procedure in pure Ada, but in the code that we
3641 -- generate in the expander, this rule needs extending because we
3642 -- can generate procedure calls that need freezing.
3644 if Is_Entity_Name (Subp) and then not In_Default_Expression then
3645 Freeze_Expression (Subp);
3646 end if;
3648 -- For a predefined operator, the type of the result is the type
3649 -- imposed by context, except for a predefined operation on universal
3650 -- fixed. Otherwise The type of the call is the type returned by the
3651 -- subprogram being called.
3653 if Is_Predefined_Op (Nam) then
3654 if Etype (N) /= Universal_Fixed then
3655 Set_Etype (N, Typ);
3656 end if;
3658 -- If the subprogram returns an array type, and the context
3659 -- requires the component type of that array type, the node is
3660 -- really an indexing of the parameterless call. Resolve as such.
3661 -- A pathological case occurs when the type of the component is
3662 -- an access to the array type. In this case the call is truly
3663 -- ambiguous.
3665 elsif Needs_No_Actuals (Nam)
3666 and then
3667 ((Is_Array_Type (Etype (Nam))
3668 and then Covers (Typ, Component_Type (Etype (Nam))))
3669 or else (Is_Access_Type (Etype (Nam))
3670 and then Is_Array_Type (Designated_Type (Etype (Nam)))
3671 and then
3672 Covers (Typ,
3673 Component_Type (Designated_Type (Etype (Nam))))))
3674 then
3675 declare
3676 Index_Node : Node_Id;
3677 New_Subp : Node_Id;
3678 Ret_Type : constant Entity_Id := Etype (Nam);
3680 begin
3681 if Is_Access_Type (Ret_Type)
3682 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
3683 then
3684 Error_Msg_N
3686 else
3687 New_Subp := Relocate_Node (Subp);
3688 Set_Entity (Subp, Nam);
3690 if Component_Type (Ret_Type) /= Any_Type then
3691 Index_Node :=
3692 Make_Indexed_Component (Loc,
3693 Prefix =>
3694 Make_Function_Call (Loc,
3695 Name => New_Subp),
3696 Expressions => Parameter_Associations (N));
3698 -- Since we are correcting a node classification error made
3699 -- by the parser, we call Replace rather than Rewrite.
3701 Replace (N, Index_Node);
3702 Set_Etype (Prefix (N), Ret_Type);
3703 Set_Etype (N, Typ);
3704 Resolve_Indexed_Component (N, Typ);
3705 Check_Elab_Call (Prefix (N));
3706 end if;
3707 end if;
3709 return;
3710 end;
3712 else
3713 Set_Etype (N, Etype (Nam));
3714 end if;
3716 -- In the case where the call is to an overloaded subprogram, Analyze
3717 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
3718 -- such a case Normalize_Actuals needs to be called once more to order
3719 -- the actuals correctly. Otherwise the call will have the ordering
3720 -- given by the last overloaded subprogram whether this is the correct
3721 -- one being called or not.
3723 if Is_Overloaded (Subp) then
3724 Normalize_Actuals (N, Nam, False, Norm_OK);
3725 pragma Assert (Norm_OK);
3726 end if;
3728 -- In any case, call is fully resolved now. Reset Overload flag, to
3729 -- prevent subsequent overload resolution if node is analyzed again
3731 Set_Is_Overloaded (Subp, False);
3732 Set_Is_Overloaded (N, False);
3734 -- If we are calling the current subprogram from immediately within
3735 -- its body, then that is the case where we can sometimes detect
3736 -- cases of infinite recursion statically. Do not try this in case
3737 -- restriction No_Recursion is in effect anyway.
3739 Scop := Current_Scope;
3741 if Nam = Scop
3742 and then not Restriction_Active (No_Recursion)
3743 and then Check_Infinite_Recursion (N)
3744 then
3745 -- Here we detected and flagged an infinite recursion, so we do
3746 -- not need to test the case below for further warnings.
3748 null;
3750 -- If call is to immediately containing subprogram, then check for
3751 -- the case of a possible run-time detectable infinite recursion.
3753 else
3754 while Scop /= Standard_Standard loop
3755 if Nam = Scop then
3756 -- Although in general recursion is not statically checkable,
3757 -- the case of calling an immediately containing subprogram
3758 -- is easy to catch.
3760 Check_Restriction (No_Recursion, N);
3762 -- If the recursive call is to a parameterless procedure, then
3763 -- even if we can't statically detect infinite recursion, this
3764 -- is pretty suspicious, and we output a warning. Furthermore,
3765 -- we will try later to detect some cases here at run time by
3766 -- expanding checking code (see Detect_Infinite_Recursion in
3767 -- package Exp_Ch6).
3769 -- If the recursive call is within a handler we do not emit a
3770 -- warning, because this is a common idiom: loop until input
3771 -- is correct, catch illegal input in handler and restart.
3773 if No (First_Formal (Nam))
3774 and then Etype (Nam) = Standard_Void_Type
3775 and then not Error_Posted (N)
3776 and then Nkind (Parent (N)) /= N_Exception_Handler
3777 then
3778 Set_Has_Recursive_Call (Nam);
3781 end if;
3783 exit;
3784 end if;
3786 Scop := Scope (Scop);
3787 end loop;
3788 end if;
3790 -- If subprogram name is a predefined operator, it was given in
3791 -- functional notation. Replace call node with operator node, so
3792 -- that actuals can be resolved appropriately.
3794 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
3795 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
3796 return;
3798 elsif Present (Alias (Nam))
3799 and then Is_Predefined_Op (Alias (Nam))
3800 then
3801 Resolve_Actuals (N, Nam);
3802 Make_Call_Into_Operator (N, Typ, Alias (Nam));
3803 return;
3804 end if;
3806 -- Create a transient scope if the resulting type requires it
3808 -- There are 3 notable exceptions: in init procs, the transient scope
3809 -- overhead is not needed and even incorrect due to the actual expansion
3810 -- of adjust calls; the second case is enumeration literal pseudo calls,
3811 -- the other case is intrinsic subprograms (Unchecked_Conversion and
3812 -- source information functions) that do not use the secondary stack
3813 -- even though the return type is unconstrained.
3815 -- If this is an initialization call for a type whose initialization
3816 -- uses the secondary stack, we also need to create a transient scope
3817 -- for it, precisely because we will not do it within the init proc
3818 -- itself.
3820 if Expander_Active
3821 and then Is_Type (Etype (Nam))
3822 and then Requires_Transient_Scope (Etype (Nam))
3823 and then Ekind (Nam) /= E_Enumeration_Literal
3824 and then not Within_Init_Proc
3825 and then not Is_Intrinsic_Subprogram (Nam)
3826 then
3827 Establish_Transient_Scope
3828 (N, Sec_Stack => not Functions_Return_By_DSP_On_Target);
3830 -- If the call appears within the bounds of a loop, it will
3831 -- be rewritten and reanalyzed, nothing left to do here.
3833 if Nkind (N) /= N_Function_Call then
3834 return;
3835 end if;
3837 elsif Is_Init_Proc (Nam)
3838 and then not Within_Init_Proc
3839 then
3840 Check_Initialization_Call (N, Nam);
3841 end if;
3843 -- A protected function cannot be called within the definition of the
3844 -- enclosing protected type.
3846 if Is_Protected_Type (Scope (Nam))
3847 and then In_Open_Scopes (Scope (Nam))
3848 and then not Has_Completion (Scope (Nam))
3849 then
3850 Error_Msg_NE
3852 end if;
3854 -- Propagate interpretation to actuals, and add default expressions
3855 -- where needed.
3857 if Present (First_Formal (Nam)) then
3858 Resolve_Actuals (N, Nam);
3860 -- Overloaded literals are rewritten as function calls, for
3861 -- purpose of resolution. After resolution, we can replace
3862 -- the call with the literal itself.
3864 elsif Ekind (Nam) = E_Enumeration_Literal then
3865 Copy_Node (Subp, N);
3866 Resolve_Entity_Name (N, Typ);
3868 -- Avoid validation, since it is a static function call
3870 return;
3871 end if;
3873 -- If the subprogram is a primitive operation, check whether or not
3874 -- it is a correct dispatching call.
3876 if Is_Overloadable (Nam)
3877 and then Is_Dispatching_Operation (Nam)
3878 then
3879 Check_Dispatching_Call (N);
3881 elsif Is_Abstract (Nam)
3882 and then not In_Instance
3883 then
3885 end if;
3887 if Is_Intrinsic_Subprogram (Nam) then
3888 Check_Intrinsic_Call (N);
3889 end if;
3891 Eval_Call (N);
3892 Check_Elab_Call (N);
3893 end Resolve_Call;
3895 -------------------------------
3896 -- Resolve_Character_Literal --
3897 -------------------------------
3899 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
3900 B_Typ : constant Entity_Id := Base_Type (Typ);
3901 C : Entity_Id;
3903 begin
3904 -- Verify that the character does belong to the type of the context
3906 Set_Etype (N, B_Typ);
3907 Eval_Character_Literal (N);
3909 -- Wide_Character literals must always be defined, since the set of
3910 -- wide character literals is complete, i.e. if a character literal
3911 -- is accepted by the parser, then it is OK for wide character.
3913 if Root_Type (B_Typ) = Standard_Wide_Character then
3914 return;
3916 -- Always accept character literal for type Any_Character, which
3917 -- occurs in error situations and in comparisons of literals, both
3918 -- of which should accept all literals.
3920 elsif B_Typ = Any_Character then
3921 return;
3923 -- For Standard.Character or a type derived from it, check that
3924 -- the literal is in range
3926 elsif Root_Type (B_Typ) = Standard_Character then
3927 if In_Character_Range (Char_Literal_Value (N)) then
3928 return;
3929 end if;
3931 -- If the entity is already set, this has already been resolved in
3932 -- a generic context, or comes from expansion. Nothing else to do.
3934 elsif Present (Entity (N)) then
3935 return;
3937 -- Otherwise we have a user defined character type, and we can use
3938 -- the standard visibility mechanisms to locate the referenced entity
3940 else
3941 C := Current_Entity (N);
3943 while Present (C) loop
3944 if Etype (C) = B_Typ then
3945 Set_Entity_With_Style_Check (N, C);
3946 Generate_Reference (C, N);
3947 return;
3948 end if;
3950 C := Homonym (C);
3951 end loop;
3952 end if;
3954 -- If we fall through, then the literal does not match any of the
3955 -- entries of the enumeration type. This isn't just a constraint
3956 -- error situation, it is an illegality (see RM 4.2).
3958 Error_Msg_NE
3960 end Resolve_Character_Literal;
3962 ---------------------------
3963 -- Resolve_Comparison_Op --
3964 ---------------------------
3966 -- Context requires a boolean type, and plays no role in resolution.
3967 -- Processing identical to that for equality operators. The result
3968 -- type is the base type, which matters when pathological subtypes of
3969 -- booleans with limited ranges are used.
3971 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
3972 L : constant Node_Id := Left_Opnd (N);
3973 R : constant Node_Id := Right_Opnd (N);
3974 T : Entity_Id;
3976 begin
3977 Check_Direct_Boolean_Op (N);
3979 -- If this is an intrinsic operation which is not predefined, use
3980 -- the types of its declared arguments to resolve the possibly
3981 -- overloaded operands. Otherwise the operands are unambiguous and
3982 -- specify the expected type.
3984 if Scope (Entity (N)) /= Standard_Standard then
3985 T := Etype (First_Entity (Entity (N)));
3986 else
3987 T := Find_Unique_Type (L, R);
3989 if T = Any_Fixed then
3990 T := Unique_Fixed_Point_Type (L);
3991 end if;
3992 end if;
3994 Set_Etype (N, Base_Type (Typ));
3995 Generate_Reference (T, N, ' ');
3997 if T /= Any_Type then
3998 if T = Any_String
3999 or else T = Any_Composite
4000 or else T = Any_Character
4001 then
4002 if T = Any_Character then
4003 Ambiguous_Character (L);
4004 else
4006 end if;
4008 Set_Etype (N, Any_Type);
4009 return;
4011 else
4012 Resolve (L, T);
4013 Resolve (R, T);
4014 Check_Unset_Reference (L);
4015 Check_Unset_Reference (R);
4016 Generate_Operator_Reference (N, T);
4017 Eval_Relational_Op (N);
4018 end if;
4019 end if;
4020 end Resolve_Comparison_Op;
4022 ------------------------------------
4023 -- Resolve_Conditional_Expression --
4024 ------------------------------------
4026 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
4027 Condition : constant Node_Id := First (Expressions (N));
4028 Then_Expr : constant Node_Id := Next (Condition);
4029 Else_Expr : constant Node_Id := Next (Then_Expr);
4031 begin
4032 Resolve (Condition, Standard_Boolean);
4033 Resolve (Then_Expr, Typ);
4034 Resolve (Else_Expr, Typ);
4036 Set_Etype (N, Typ);
4037 Eval_Conditional_Expression (N);
4038 end Resolve_Conditional_Expression;
4040 -----------------------------------------
4041 -- Resolve_Discrete_Subtype_Indication --
4042 -----------------------------------------
4044 procedure Resolve_Discrete_Subtype_Indication
4045 (N : Node_Id;
4046 Typ : Entity_Id)
4047 is
4048 R : Node_Id;
4049 S : Entity_Id;
4051 begin
4052 Analyze (Subtype_Mark (N));
4053 S := Entity (Subtype_Mark (N));
4055 if Nkind (Constraint (N)) /= N_Range_Constraint then
4057 Set_Etype (N, Any_Type);
4059 else
4060 R := Range_Expression (Constraint (N));
4062 if R = Error then
4063 return;
4064 end if;
4066 Analyze (R);
4068 if Base_Type (S) /= Base_Type (Typ) then
4069 Error_Msg_NE
4072 -- Rewrite the constraint as a range of Typ
4073 -- to allow compilation to proceed further.
4075 Set_Etype (N, Typ);
4076 Rewrite (Low_Bound (R),
4077 Make_Attribute_Reference (Sloc (Low_Bound (R)),
4078 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4079 Attribute_Name => Name_First));
4080 Rewrite (High_Bound (R),
4081 Make_Attribute_Reference (Sloc (High_Bound (R)),
4082 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4083 Attribute_Name => Name_First));
4085 else
4086 Resolve (R, Typ);
4087 Set_Etype (N, Etype (R));
4089 -- Additionally, we must check that the bounds are compatible
4090 -- with the given subtype, which might be different from the
4091 -- type of the context.
4093 Apply_Range_Check (R, S);
4095 -- ??? If the above check statically detects a Constraint_Error
4096 -- it replaces the offending bound(s) of the range R with a
4097 -- Constraint_Error node. When the itype which uses these bounds
4098 -- is frozen the resulting call to Duplicate_Subexpr generates
4099 -- a new temporary for the bounds.
4101 -- Unfortunately there are other itypes that are also made depend
4102 -- on these bounds, so when Duplicate_Subexpr is called they get
4103 -- a forward reference to the newly created temporaries and Gigi
4104 -- aborts on such forward references. This is probably sign of a
4105 -- more fundamental problem somewhere else in either the order of
4106 -- itype freezing or the way certain itypes are constructed.
4108 -- To get around this problem we call Remove_Side_Effects right
4109 -- away if either bounds of R are a Constraint_Error.
4111 declare
4112 L : constant Node_Id := Low_Bound (R);
4113 H : constant Node_Id := High_Bound (R);
4115 begin
4116 if Nkind (L) = N_Raise_Constraint_Error then
4117 Remove_Side_Effects (L);
4118 end if;
4120 if Nkind (H) = N_Raise_Constraint_Error then
4121 Remove_Side_Effects (H);
4122 end if;
4123 end;
4125 Check_Unset_Reference (Low_Bound (R));
4126 Check_Unset_Reference (High_Bound (R));
4127 end if;
4128 end if;
4129 end Resolve_Discrete_Subtype_Indication;
4131 -------------------------
4132 -- Resolve_Entity_Name --
4133 -------------------------
4135 -- Used to resolve identifiers and expanded names
4137 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
4138 E : constant Entity_Id := Entity (N);
4140 begin
4141 -- If garbage from errors, set to Any_Type and return
4143 if No (E) and then Total_Errors_Detected /= 0 then
4144 Set_Etype (N, Any_Type);
4145 return;
4146 end if;
4148 -- Replace named numbers by corresponding literals. Note that this is
4149 -- the one case where Resolve_Entity_Name must reset the Etype, since
4150 -- it is currently marked as universal.
4152 if Ekind (E) = E_Named_Integer then
4153 Set_Etype (N, Typ);
4154 Eval_Named_Integer (N);
4156 elsif Ekind (E) = E_Named_Real then
4157 Set_Etype (N, Typ);
4158 Eval_Named_Real (N);
4160 -- Allow use of subtype only if it is a concurrent type where we are
4161 -- currently inside the body. This will eventually be expanded
4162 -- into a call to Self (for tasks) or _object (for protected
4163 -- objects). Any other use of a subtype is invalid.
4165 elsif Is_Type (E) then
4166 if Is_Concurrent_Type (E)
4167 and then In_Open_Scopes (E)
4168 then
4169 null;
4170 else
4171 Error_Msg_N
4173 end if;
4175 -- Check discriminant use if entity is discriminant in current scope,
4176 -- i.e. discriminant of record or concurrent type currently being
4177 -- analyzed. Uses in corresponding body are unrestricted.
4179 elsif Ekind (E) = E_Discriminant
4180 and then Scope (E) = Current_Scope
4181 and then not Has_Completion (Current_Scope)
4182 then
4183 Check_Discriminant_Use (N);
4185 -- A parameterless generic function cannot appear in a context that
4186 -- requires resolution.
4188 elsif Ekind (E) = E_Generic_Function then
4191 elsif Ekind (E) = E_Out_Parameter
4192 and then Ada_Version = Ada_83
4193 and then (Nkind (Parent (N)) in N_Op
4194 or else (Nkind (Parent (N)) = N_Assignment_Statement
4195 and then N = Expression (Parent (N)))
4196 or else Nkind (Parent (N)) = N_Explicit_Dereference)
4197 then
4200 -- In all other cases, just do the possible static evaluation
4202 else
4203 -- A deferred constant that appears in an expression must have
4204 -- a completion, unless it has been removed by in-place expansion
4205 -- of an aggregate.
4207 if Ekind (E) = E_Constant
4208 and then Comes_From_Source (E)
4209 and then No (Constant_Value (E))
4210 and then Is_Frozen (Etype (E))
4211 and then not In_Default_Expression
4212 and then not Is_Imported (E)
4213 then
4215 if No_Initialization (Parent (E))
4216 or else (Present (Full_View (E))
4217 and then No_Initialization (Parent (Full_View (E))))
4218 then
4219 null;
4220 else
4221 Error_Msg_N (
4223 end if;
4224 end if;
4226 Eval_Entity_Name (N);
4227 end if;
4228 end Resolve_Entity_Name;
4230 -------------------
4231 -- Resolve_Entry --
4232 -------------------
4234 procedure Resolve_Entry (Entry_Name : Node_Id) is
4235 Loc : constant Source_Ptr := Sloc (Entry_Name);
4236 Nam : Entity_Id;
4237 New_N : Node_Id;
4238 S : Entity_Id;
4239 Tsk : Entity_Id;
4240 E_Name : Node_Id;
4241 Index : Node_Id;
4243 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
4244 -- If the bounds of the entry family being called depend on task
4245 -- discriminants, build a new index subtype where a discriminant is
4246 -- replaced with the value of the discriminant of the target task.
4247 -- The target task is the prefix of the entry name in the call.
4249 -----------------------
4250 -- Actual_Index_Type --
4251 -----------------------
4253 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
4254 Typ : constant Entity_Id := Entry_Index_Type (E);
4255 Tsk : constant Entity_Id := Scope (E);
4256 Lo : constant Node_Id := Type_Low_Bound (Typ);
4257 Hi : constant Node_Id := Type_High_Bound (Typ);
4258 New_T : Entity_Id;
4260 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
4261 -- If the bound is given by a discriminant, replace with a reference
4262 -- to the discriminant of the same name in the target task.
4263 -- If the entry name is the target of a requeue statement and the
4264 -- entry is in the current protected object, the bound to be used
4265 -- is the discriminal of the object (see apply_range_checks for
4266 -- details of the transformation).
4268 -----------------------------
4269 -- Actual_Discriminant_Ref --
4270 -----------------------------
4272 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
4273 Typ : constant Entity_Id := Etype (Bound);
4274 Ref : Node_Id;
4276 begin
4277 Remove_Side_Effects (Bound);
4279 if not Is_Entity_Name (Bound)
4280 or else Ekind (Entity (Bound)) /= E_Discriminant
4281 then
4282 return Bound;
4284 elsif Is_Protected_Type (Tsk)
4285 and then In_Open_Scopes (Tsk)
4286 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
4287 then
4288 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
4290 else
4291 Ref :=
4292 Make_Selected_Component (Loc,
4293 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
4294 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
4295 Analyze (Ref);
4296 Resolve (Ref, Typ);
4297 return Ref;
4298 end if;
4299 end Actual_Discriminant_Ref;
4301 -- Start of processing for Actual_Index_Type
4303 begin
4304 if not Has_Discriminants (Tsk)
4305 or else (not Is_Entity_Name (Lo)
4306 and then not Is_Entity_Name (Hi))
4307 then
4308 return Entry_Index_Type (E);
4310 else
4311 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
4312 Set_Etype (New_T, Base_Type (Typ));
4313 Set_Size_Info (New_T, Typ);
4314 Set_RM_Size (New_T, RM_Size (Typ));
4315 Set_Scalar_Range (New_T,
4316 Make_Range (Sloc (Entry_Name),
4317 Low_Bound => Actual_Discriminant_Ref (Lo),
4318 High_Bound => Actual_Discriminant_Ref (Hi)));
4320 return New_T;
4321 end if;
4322 end Actual_Index_Type;
4324 -- Start of processing of Resolve_Entry
4326 begin
4327 -- Find name of entry being called, and resolve prefix of name
4328 -- with its own type. The prefix can be overloaded, and the name
4329 -- and signature of the entry must be taken into account.
4331 if Nkind (Entry_Name) = N_Indexed_Component then
4333 -- Case of dealing with entry family within the current tasks
4335 E_Name := Prefix (Entry_Name);
4337 else
4338 E_Name := Entry_Name;
4339 end if;
4341 if Is_Entity_Name (E_Name) then
4342 -- Entry call to an entry (or entry family) in the current task.
4343 -- This is legal even though the task will deadlock. Rewrite as
4344 -- call to current task.
4346 -- This can also be a call to an entry in an enclosing task.
4347 -- If this is a single task, we have to retrieve its name,
4348 -- because the scope of the entry is the task type, not the
4349 -- object. If the enclosing task is a task type, the identity
4350 -- of the task is given by its own self variable.
4352 -- Finally this can be a requeue on an entry of the same task
4353 -- or protected object.
4355 S := Scope (Entity (E_Name));
4357 for J in reverse 0 .. Scope_Stack.Last loop
4359 if Is_Task_Type (Scope_Stack.Table (J).Entity)
4360 and then not Comes_From_Source (S)
4361 then
4362 -- S is an enclosing task or protected object. The concurrent
4363 -- declaration has been converted into a type declaration, and
4364 -- the object itself has an object declaration that follows
4365 -- the type in the same declarative part.
4367 Tsk := Next_Entity (S);
4369 while Etype (Tsk) /= S loop
4370 Next_Entity (Tsk);
4371 end loop;
4373 S := Tsk;
4374 exit;
4376 elsif S = Scope_Stack.Table (J).Entity then
4378 -- Call to current task. Will be transformed into call to Self
4380 exit;
4382 end if;
4383 end loop;
4385 New_N :=
4386 Make_Selected_Component (Loc,
4387 Prefix => New_Occurrence_Of (S, Loc),
4388 Selector_Name =>
4389 New_Occurrence_Of (Entity (E_Name), Loc));
4390 Rewrite (E_Name, New_N);
4391 Analyze (E_Name);
4393 elsif Nkind (Entry_Name) = N_Selected_Component
4394 and then Is_Overloaded (Prefix (Entry_Name))
4395 then
4396 -- Use the entry name (which must be unique at this point) to
4397 -- find the prefix that returns the corresponding task type or
4398 -- protected type.
4400 declare
4401 Pref : constant Node_Id := Prefix (Entry_Name);
4402 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
4403 I : Interp_Index;
4404 It : Interp;
4406 begin
4407 Get_First_Interp (Pref, I, It);
4409 while Present (It.Typ) loop
4411 if Scope (Ent) = It.Typ then
4412 Set_Etype (Pref, It.Typ);
4413 exit;
4414 end if;
4416 Get_Next_Interp (I, It);
4417 end loop;
4418 end;
4419 end if;
4421 if Nkind (Entry_Name) = N_Selected_Component then
4422 Resolve (Prefix (Entry_Name));
4424 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4425 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4426 Resolve (Prefix (Prefix (Entry_Name)));
4427 Index := First (Expressions (Entry_Name));
4428 Resolve (Index, Entry_Index_Type (Nam));
4430 -- Up to this point the expression could have been the actual
4431 -- in a simple entry call, and be given by a named association.
4433 if Nkind (Index) = N_Parameter_Association then
4435 else
4436 Apply_Range_Check (Index, Actual_Index_Type (Nam));
4437 end if;
4438 end if;
4439 end Resolve_Entry;
4441 ------------------------
4442 -- Resolve_Entry_Call --
4443 ------------------------
4445 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
4446 Entry_Name : constant Node_Id := Name (N);
4447 Loc : constant Source_Ptr := Sloc (Entry_Name);
4448 Actuals : List_Id;
4449 First_Named : Node_Id;
4450 Nam : Entity_Id;
4451 Norm_OK : Boolean;
4452 Obj : Node_Id;
4453 Was_Over : Boolean;
4455 begin
4456 -- We kill all checks here, because it does not seem worth the
4457 -- effort to do anything better, an entry call is a big operation.
4459 Kill_All_Checks;
4461 -- Processing of the name is similar for entry calls and protected
4462 -- operation calls. Once the entity is determined, we can complete
4463 -- the resolution of the actuals.
4465 -- The selector may be overloaded, in the case of a protected object
4466 -- with overloaded functions. The type of the context is used for
4467 -- resolution.
4469 if Nkind (Entry_Name) = N_Selected_Component
4470 and then Is_Overloaded (Selector_Name (Entry_Name))
4471 and then Typ /= Standard_Void_Type
4472 then
4473 declare
4474 I : Interp_Index;
4475 It : Interp;
4477 begin
4478 Get_First_Interp (Selector_Name (Entry_Name), I, It);
4480 while Present (It.Typ) loop
4482 if Covers (Typ, It.Typ) then
4483 Set_Entity (Selector_Name (Entry_Name), It.Nam);
4484 Set_Etype (Entry_Name, It.Typ);
4486 Generate_Reference (It.Typ, N, ' ');
4487 end if;
4489 Get_Next_Interp (I, It);
4490 end loop;
4491 end;
4492 end if;
4494 Resolve_Entry (Entry_Name);
4496 if Nkind (Entry_Name) = N_Selected_Component then
4498 -- Simple entry call.
4500 Nam := Entity (Selector_Name (Entry_Name));
4501 Obj := Prefix (Entry_Name);
4502 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
4504 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4506 -- Call to member of entry family.
4508 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4509 Obj := Prefix (Prefix (Entry_Name));
4510 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
4511 end if;
4513 -- We cannot in general check the maximum depth of protected entry
4514 -- calls at compile time. But we can tell that any protected entry
4515 -- call at all violates a specified nesting depth of zero.
4517 if Is_Protected_Type (Scope (Nam)) then
4518 Check_Restriction (Max_Entry_Queue_Length, N);
4519 end if;
4521 -- Use context type to disambiguate a protected function that can be
4522 -- called without actuals and that returns an array type, and where
4523 -- the argument list may be an indexing of the returned value.
4525 if Ekind (Nam) = E_Function
4526 and then Needs_No_Actuals (Nam)
4527 and then Present (Parameter_Associations (N))
4528 and then
4529 ((Is_Array_Type (Etype (Nam))
4530 and then Covers (Typ, Component_Type (Etype (Nam))))
4532 or else (Is_Access_Type (Etype (Nam))
4533 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4534 and then Covers (Typ,
4535 Component_Type (Designated_Type (Etype (Nam))))))
4536 then
4537 declare
4538 Index_Node : Node_Id;
4540 begin
4541 Index_Node :=
4542 Make_Indexed_Component (Loc,
4543 Prefix =>
4544 Make_Function_Call (Loc,
4545 Name => Relocate_Node (Entry_Name)),
4546 Expressions => Parameter_Associations (N));
4548 -- Since we are correcting a node classification error made by
4549 -- the parser, we call Replace rather than Rewrite.
4551 Replace (N, Index_Node);
4552 Set_Etype (Prefix (N), Etype (Nam));
4553 Set_Etype (N, Typ);
4554 Resolve_Indexed_Component (N, Typ);
4555 return;
4556 end;
4557 end if;
4559 -- The operation name may have been overloaded. Order the actuals
4560 -- according to the formals of the resolved entity, and set the
4561 -- return type to that of the operation.
4563 if Was_Over then
4564 Normalize_Actuals (N, Nam, False, Norm_OK);
4565 pragma Assert (Norm_OK);
4566 Set_Etype (N, Etype (Nam));
4567 end if;
4569 Resolve_Actuals (N, Nam);
4570 Generate_Reference (Nam, Entry_Name);
4572 if Ekind (Nam) = E_Entry
4573 or else Ekind (Nam) = E_Entry_Family
4574 then
4575 Check_Potentially_Blocking_Operation (N);
4576 end if;
4578 -- Verify that a procedure call cannot masquerade as an entry
4579 -- call where an entry call is expected.
4581 if Ekind (Nam) = E_Procedure then
4582 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4583 and then N = Entry_Call_Statement (Parent (N))
4584 then
4587 elsif Nkind (Parent (N)) = N_Triggering_Alternative
4588 and then N = Triggering_Statement (Parent (N))
4589 then
4592 elsif Ekind (Scope (Nam)) = E_Task_Type
4593 and then not In_Open_Scopes (Scope (Nam))
4594 then
4596 end if;
4597 end if;
4599 -- After resolution, entry calls and protected procedure calls
4600 -- are changed into entry calls, for expansion. The structure
4601 -- of the node does not change, so it can safely be done in place.
4602 -- Protected function calls must keep their structure because they
4603 -- are subexpressions.
4605 if Ekind (Nam) /= E_Function then
4607 -- A protected operation that is not a function may modify the
4608 -- corresponding object, and cannot apply to a constant.
4609 -- If this is an internal call, the prefix is the type itself.
4611 if Is_Protected_Type (Scope (Nam))
4612 and then not Is_Variable (Obj)
4613 and then (not Is_Entity_Name (Obj)
4614 or else not Is_Type (Entity (Obj)))
4615 then
4616 Error_Msg_N
4618 Entry_Name);
4619 end if;
4621 Actuals := Parameter_Associations (N);
4622 First_Named := First_Named_Actual (N);
4624 Rewrite (N,
4625 Make_Entry_Call_Statement (Loc,
4626 Name => Entry_Name,
4627 Parameter_Associations => Actuals));
4629 Set_First_Named_Actual (N, First_Named);
4630 Set_Analyzed (N, True);
4632 -- Protected functions can return on the secondary stack, in which
4633 -- case we must trigger the transient scope mechanism
4635 elsif Expander_Active
4636 and then Requires_Transient_Scope (Etype (Nam))
4637 then
4638 Establish_Transient_Scope (N,
4639 Sec_Stack => not Functions_Return_By_DSP_On_Target);
4640 end if;
4641 end Resolve_Entry_Call;
4643 -------------------------
4644 -- Resolve_Equality_Op --
4645 -------------------------
4647 -- Both arguments must have the same type, and the boolean context
4648 -- does not participate in the resolution. The first pass verifies
4649 -- that the interpretation is not ambiguous, and the type of the left
4650 -- argument is correctly set, or is Any_Type in case of ambiguity.
4651 -- If both arguments are strings or aggregates, allocators, or Null,
4652 -- they are ambiguous even though they carry a single (universal) type.
4653 -- Diagnose this case here.
4655 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
4656 L : constant Node_Id := Left_Opnd (N);
4657 R : constant Node_Id := Right_Opnd (N);
4658 T : Entity_Id := Find_Unique_Type (L, R);
4660 function Find_Unique_Access_Type return Entity_Id;
4661 -- In the case of allocators, make a last-ditch attempt to find a single
4662 -- access type with the right designated type. This is semantically
4663 -- dubious, and of no interest to any real code, but c48008a makes it
4664 -- all worthwhile.
4666 -----------------------------
4667 -- Find_Unique_Access_Type --
4668 -----------------------------
4670 function Find_Unique_Access_Type return Entity_Id is
4671 Acc : Entity_Id;
4672 E : Entity_Id;
4673 S : Entity_Id := Current_Scope;
4675 begin
4676 if Ekind (Etype (R)) = E_Allocator_Type then
4677 Acc := Designated_Type (Etype (R));
4679 elsif Ekind (Etype (L)) = E_Allocator_Type then
4680 Acc := Designated_Type (Etype (L));
4682 else
4683 return Empty;
4684 end if;
4686 while S /= Standard_Standard loop
4687 E := First_Entity (S);
4689 while Present (E) loop
4691 if Is_Type (E)
4692 and then Is_Access_Type (E)
4693 and then Ekind (E) /= E_Allocator_Type
4694 and then Designated_Type (E) = Base_Type (Acc)
4695 then
4696 return E;
4697 end if;
4699 Next_Entity (E);
4700 end loop;
4702 S := Scope (S);
4703 end loop;
4705 return Empty;
4706 end Find_Unique_Access_Type;
4708 -- Start of processing for Resolve_Equality_Op
4710 begin
4711 Check_Direct_Boolean_Op (N);
4713 Set_Etype (N, Base_Type (Typ));
4714 Generate_Reference (T, N, ' ');
4716 if T = Any_Fixed then
4717 T := Unique_Fixed_Point_Type (L);
4718 end if;
4720 if T /= Any_Type then
4722 if T = Any_String
4723 or else T = Any_Composite
4724 or else T = Any_Character
4725 then
4727 if T = Any_Character then
4728 Ambiguous_Character (L);
4729 else
4731 end if;
4733 Set_Etype (N, Any_Type);
4734 return;
4736 elsif T = Any_Access
4737 or else Ekind (T) = E_Allocator_Type
4738 then
4739 T := Find_Unique_Access_Type;
4741 if No (T) then
4743 Set_Etype (N, Any_Type);
4744 return;
4745 end if;
4746 end if;
4748 Resolve (L, T);
4749 Resolve (R, T);
4751 if Warn_On_Redundant_Constructs
4752 and then Comes_From_Source (N)
4753 and then Is_Entity_Name (R)
4754 and then Entity (R) = Standard_True
4755 and then Comes_From_Source (R)
4756 then
4758 end if;
4760 Check_Unset_Reference (L);
4761 Check_Unset_Reference (R);
4762 Generate_Operator_Reference (N, T);
4764 -- If this is an inequality, it may be the implicit inequality
4765 -- created for a user-defined operation, in which case the corres-
4766 -- ponding equality operation is not intrinsic, and the operation
4767 -- cannot be constant-folded. Else fold.
4769 if Nkind (N) = N_Op_Eq
4770 or else Comes_From_Source (Entity (N))
4771 or else Ekind (Entity (N)) = E_Operator
4772 or else Is_Intrinsic_Subprogram
4773 (Corresponding_Equality (Entity (N)))
4774 then
4775 Eval_Relational_Op (N);
4776 elsif Nkind (N) = N_Op_Ne
4777 and then Is_Abstract (Entity (N))
4778 then
4780 end if;
4781 end if;
4782 end Resolve_Equality_Op;
4784 ----------------------------------
4785 -- Resolve_Explicit_Dereference --
4786 ----------------------------------
4788 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
4789 P : constant Node_Id := Prefix (N);
4790 I : Interp_Index;
4791 It : Interp;
4793 begin
4794 -- Now that we know the type, check that this is not a
4795 -- dereference of an uncompleted type. Note that this
4796 -- is not entirely correct, because dereferences of
4797 -- private types are legal in default expressions.
4798 -- This consideration also applies to similar checks
4799 -- for allocators, qualified expressions, and type
4800 -- conversions. ???
4802 Check_Fully_Declared (Typ, N);
4804 if Is_Overloaded (P) then
4806 -- Use the context type to select the prefix that has the
4807 -- correct designated type.
4809 Get_First_Interp (P, I, It);
4810 while Present (It.Typ) loop
4811 exit when Is_Access_Type (It.Typ)
4812 and then Covers (Typ, Designated_Type (It.Typ));
4814 Get_Next_Interp (I, It);
4815 end loop;
4817 Resolve (P, It.Typ);
4818 Set_Etype (N, Designated_Type (It.Typ));
4820 else
4821 Resolve (P);
4822 end if;
4824 if Is_Access_Type (Etype (P)) then
4825 Apply_Access_Check (N);
4826 end if;
4828 -- If the designated type is a packed unconstrained array type,
4829 -- and the explicit dereference is not in the context of an
4830 -- attribute reference, then we must compute and set the actual
4831 -- subtype, since it is needed by Gigi. The reason we exclude
4832 -- the attribute case is that this is handled fine by Gigi, and
4833 -- in fact we use such attributes to build the actual subtype.
4834 -- We also exclude generated code (which builds actual subtypes
4835 -- directly if they are needed).
4837 if Is_Array_Type (Etype (N))
4838 and then Is_Packed (Etype (N))
4839 and then not Is_Constrained (Etype (N))
4840 and then Nkind (Parent (N)) /= N_Attribute_Reference
4841 and then Comes_From_Source (N)
4842 then
4843 Set_Etype (N, Get_Actual_Subtype (N));
4844 end if;
4846 -- Note: there is no Eval processing required for an explicit
4847 -- deference, because the type is known to be an allocators, and
4848 -- allocator expressions can never be static.
4850 end Resolve_Explicit_Dereference;
4852 -------------------------------
4853 -- Resolve_Indexed_Component --
4854 -------------------------------
4856 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
4857 Name : constant Node_Id := Prefix (N);
4858 Expr : Node_Id;
4859 Array_Type : Entity_Id := Empty; -- to prevent junk warning
4860 Index : Node_Id;
4862 begin
4863 if Is_Overloaded (Name) then
4865 -- Use the context type to select the prefix that yields the
4866 -- correct component type.
4868 declare
4869 I : Interp_Index;
4870 It : Interp;
4871 I1 : Interp_Index := 0;
4872 P : constant Node_Id := Prefix (N);
4873 Found : Boolean := False;
4875 begin
4876 Get_First_Interp (P, I, It);
4878 while Present (It.Typ) loop
4880 if (Is_Array_Type (It.Typ)
4881 and then Covers (Typ, Component_Type (It.Typ)))
4882 or else (Is_Access_Type (It.Typ)
4883 and then Is_Array_Type (Designated_Type (It.Typ))
4884 and then Covers
4885 (Typ, Component_Type (Designated_Type (It.Typ))))
4886 then
4887 if Found then
4888 It := Disambiguate (P, I1, I, Any_Type);
4890 if It = No_Interp then
4892 Set_Etype (N, Typ);
4893 return;
4895 else
4896 Found := True;
4897 Array_Type := It.Typ;
4898 I1 := I;
4899 end if;
4901 else
4902 Found := True;
4903 Array_Type := It.Typ;
4904 I1 := I;
4905 end if;
4906 end if;
4908 Get_Next_Interp (I, It);
4909 end loop;
4910 end;
4912 else
4913 Array_Type := Etype (Name);
4914 end if;
4916 Resolve (Name, Array_Type);
4917 Array_Type := Get_Actual_Subtype_If_Available (Name);
4919 -- If prefix is access type, dereference to get real array type.
4920 -- Note: we do not apply an access check because the expander always
4921 -- introduces an explicit dereference, and the check will happen there.
4923 if Is_Access_Type (Array_Type) then
4924 Array_Type := Designated_Type (Array_Type);
4925 end if;
4927 -- If name was overloaded, set component type correctly now.
4929 Set_Etype (N, Component_Type (Array_Type));
4931 Index := First_Index (Array_Type);
4932 Expr := First (Expressions (N));
4934 -- The prefix may have resolved to a string literal, in which case
4935 -- its etype has a special representation. This is only possible
4936 -- currently if the prefix is a static concatenation, written in
4937 -- functional notation.
4939 if Ekind (Array_Type) = E_String_Literal_Subtype then
4940 Resolve (Expr, Standard_Positive);
4942 else
4943 while Present (Index) and Present (Expr) loop
4944 Resolve (Expr, Etype (Index));
4945 Check_Unset_Reference (Expr);
4947 if Is_Scalar_Type (Etype (Expr)) then
4948 Apply_Scalar_Range_Check (Expr, Etype (Index));
4949 else
4950 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
4951 end if;
4953 Next_Index (Index);
4954 Next (Expr);
4955 end loop;
4956 end if;
4958 Eval_Indexed_Component (N);
4959 end Resolve_Indexed_Component;
4961 -----------------------------
4962 -- Resolve_Integer_Literal --
4963 -----------------------------
4965 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
4966 begin
4967 Set_Etype (N, Typ);
4968 Eval_Integer_Literal (N);
4969 end Resolve_Integer_Literal;
4971 --------------------------------
4972 -- Resolve_Intrinsic_Operator --
4973 --------------------------------
4975 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
4976 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
4977 Op : Entity_Id;
4978 Arg1 : Node_Id;
4979 Arg2 : Node_Id;
4981 begin
4982 Op := Entity (N);
4984 while Scope (Op) /= Standard_Standard loop
4985 Op := Homonym (Op);
4986 pragma Assert (Present (Op));
4987 end loop;
4989 Set_Entity (N, Op);
4990 Set_Is_Overloaded (N, False);
4992 -- If the operand type is private, rewrite with suitable
4993 -- conversions on the operands and the result, to expose
4994 -- the proper underlying numeric type.
4996 if Is_Private_Type (Typ) then
4997 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
4999 if Nkind (N) = N_Op_Expon then
5000 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
5001 else
5002 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5003 end if;
5005 Save_Interps (Left_Opnd (N), Expression (Arg1));
5006 Save_Interps (Right_Opnd (N), Expression (Arg2));
5008 Set_Left_Opnd (N, Arg1);
5009 Set_Right_Opnd (N, Arg2);
5011 Set_Etype (N, Btyp);
5012 Rewrite (N, Unchecked_Convert_To (Typ, N));
5013 Resolve (N, Typ);
5015 elsif Typ /= Etype (Left_Opnd (N))
5016 or else Typ /= Etype (Right_Opnd (N))
5017 then
5018 -- Add explicit conversion where needed, and save interpretations
5019 -- in case operands are overloaded.
5021 Arg1 := Convert_To (Typ, Left_Opnd (N));
5022 Arg2 := Convert_To (Typ, Right_Opnd (N));
5024 if Nkind (Arg1) = N_Type_Conversion then
5025 Save_Interps (Left_Opnd (N), Expression (Arg1));
5026 else
5027 Save_Interps (Left_Opnd (N), Arg1);
5028 end if;
5030 if Nkind (Arg2) = N_Type_Conversion then
5031 Save_Interps (Right_Opnd (N), Expression (Arg2));
5032 else
5033 Save_Interps (Right_Opnd (N), Arg2);
5034 end if;
5036 Rewrite (Left_Opnd (N), Arg1);
5037 Rewrite (Right_Opnd (N), Arg2);
5038 Analyze (Arg1);
5039 Analyze (Arg2);
5040 Resolve_Arithmetic_Op (N, Typ);
5042 else
5043 Resolve_Arithmetic_Op (N, Typ);
5044 end if;
5045 end Resolve_Intrinsic_Operator;
5047 --------------------------------------
5048 -- Resolve_Intrinsic_Unary_Operator --
5049 --------------------------------------
5051 procedure Resolve_Intrinsic_Unary_Operator
5052 (N : Node_Id;
5053 Typ : Entity_Id)
5054 is
5055 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
5056 Op : Entity_Id;
5057 Arg2 : Node_Id;
5059 begin
5060 Op := Entity (N);
5062 while Scope (Op) /= Standard_Standard loop
5063 Op := Homonym (Op);
5064 pragma Assert (Present (Op));
5065 end loop;
5067 Set_Entity (N, Op);
5069 if Is_Private_Type (Typ) then
5070 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5071 Save_Interps (Right_Opnd (N), Expression (Arg2));
5073 Set_Right_Opnd (N, Arg2);
5075 Set_Etype (N, Btyp);
5076 Rewrite (N, Unchecked_Convert_To (Typ, N));
5077 Resolve (N, Typ);
5079 else
5080 Resolve_Unary_Op (N, Typ);
5081 end if;
5082 end Resolve_Intrinsic_Unary_Operator;
5084 ------------------------
5085 -- Resolve_Logical_Op --
5086 ------------------------
5088 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
5089 B_Typ : Entity_Id;
5091 begin
5092 Check_Direct_Boolean_Op (N);
5094 -- Predefined operations on scalar types yield the base type. On
5095 -- the other hand, logical operations on arrays yield the type of
5096 -- the arguments (and the context).
5098 if Is_Array_Type (Typ) then
5099 B_Typ := Typ;
5100 else
5101 B_Typ := Base_Type (Typ);
5102 end if;
5104 -- The following test is required because the operands of the operation
5105 -- may be literals, in which case the resulting type appears to be
5106 -- compatible with a signed integer type, when in fact it is compatible
5107 -- only with modular types. If the context itself is universal, the
5108 -- operation is illegal.
5110 if not Valid_Boolean_Arg (Typ) then
5112 Set_Etype (N, Any_Type);
5113 return;
5115 elsif Typ = Any_Modular then
5116 Error_Msg_N
5118 Set_Etype (N, Any_Type);
5119 return;
5120 elsif Is_Modular_Integer_Type (Typ)
5121 and then Etype (Left_Opnd (N)) = Universal_Integer
5122 and then Etype (Right_Opnd (N)) = Universal_Integer
5123 then
5124 Check_For_Visible_Operator (N, B_Typ);
5125 end if;
5127 Resolve (Left_Opnd (N), B_Typ);
5128 Resolve (Right_Opnd (N), B_Typ);
5130 Check_Unset_Reference (Left_Opnd (N));
5131 Check_Unset_Reference (Right_Opnd (N));
5133 Set_Etype (N, B_Typ);
5134 Generate_Operator_Reference (N, B_Typ);
5135 Eval_Logical_Op (N);
5136 end Resolve_Logical_Op;
5138 ---------------------------
5139 -- Resolve_Membership_Op --
5140 ---------------------------
5142 -- The context can only be a boolean type, and does not determine
5143 -- the arguments. Arguments should be unambiguous, but the preference
5144 -- rule for universal types applies.
5146 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
5147 pragma Warnings (Off, Typ);
5149 L : constant Node_Id := Left_Opnd (N);
5150 R : constant Node_Id := Right_Opnd (N);
5151 T : Entity_Id;
5153 begin
5154 if L = Error or else R = Error then
5155 return;
5156 end if;
5158 if not Is_Overloaded (R)
5159 and then
5160 (Etype (R) = Universal_Integer or else
5161 Etype (R) = Universal_Real)
5162 and then Is_Overloaded (L)
5163 then
5164 T := Etype (R);
5165 else
5166 T := Intersect_Types (L, R);
5167 end if;
5169 Resolve (L, T);
5170 Check_Unset_Reference (L);
5172 if Nkind (R) = N_Range
5173 and then not Is_Scalar_Type (T)
5174 then
5176 end if;
5178 if Is_Entity_Name (R) then
5179 Freeze_Expression (R);
5180 else
5181 Resolve (R, T);
5182 Check_Unset_Reference (R);
5183 end if;
5185 Eval_Membership_Op (N);
5186 end Resolve_Membership_Op;
5188 ------------------
5189 -- Resolve_Null --
5190 ------------------
5192 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
5193 begin
5194 -- Handle restriction against anonymous null access values
5195 -- This restriction can be turned off using -gnatdh.
5197 -- Ada 2005 (AI-231): Remove restriction
5199 if Ada_Version < Ada_05
5200 and then not Debug_Flag_J
5201 and then Ekind (Typ) = E_Anonymous_Access_Type
5202 and then Comes_From_Source (N)
5203 then
5204 -- In the common case of a call which uses an explicitly null
5205 -- value for an access parameter, give specialized error msg
5207 if Nkind (Parent (N)) = N_Procedure_Call_Statement
5208 or else
5209 Nkind (Parent (N)) = N_Function_Call
5210 then
5211 Error_Msg_N
5214 -- Standard message for all other cases (are there any?)
5216 else
5217 Error_Msg_N
5219 end if;
5220 end if;
5222 -- In a distributed context, null for a remote access to subprogram
5223 -- may need to be replaced with a special record aggregate. In this
5224 -- case, return after having done the transformation.
5226 if (Ekind (Typ) = E_Record_Type
5227 or else Is_Remote_Access_To_Subprogram_Type (Typ))
5228 and then Remote_AST_Null_Value (N, Typ)
5229 then
5230 return;
5231 end if;
5233 -- The null literal takes its type from the context.
5235 Set_Etype (N, Typ);
5236 end Resolve_Null;
5238 -----------------------
5239 -- Resolve_Op_Concat --
5240 -----------------------
5242 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
5243 Btyp : constant Entity_Id := Base_Type (Typ);
5244 Op1 : constant Node_Id := Left_Opnd (N);
5245 Op2 : constant Node_Id := Right_Opnd (N);
5247 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean);
5248 -- Internal procedure to resolve one operand of concatenation operator.
5249 -- The operand is either of the array type or of the component type.
5250 -- If the operand is an aggregate, and the component type is composite,
5251 -- this is ambiguous if component type has aggregates.
5253 -------------------------------
5254 -- Resolve_Concatenation_Arg --
5255 -------------------------------
5257 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean) is
5258 begin
5259 if In_Instance then
5260 if Is_Comp
5261 or else (not Is_Overloaded (Arg)
5262 and then Etype (Arg) /= Any_Composite
5263 and then Covers (Component_Type (Typ), Etype (Arg)))
5264 then
5265 Resolve (Arg, Component_Type (Typ));
5266 else
5267 Resolve (Arg, Btyp);
5268 end if;
5270 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
5272 if Nkind (Arg) = N_Aggregate
5273 and then Is_Composite_Type (Component_Type (Typ))
5274 then
5275 if Is_Private_Type (Component_Type (Typ)) then
5276 Resolve (Arg, Btyp);
5278 else
5280 Set_Etype (Arg, Any_Type);
5281 end if;
5283 else
5284 if Is_Overloaded (Arg)
5285 and then Has_Compatible_Type (Arg, Typ)
5286 and then Etype (Arg) /= Any_Type
5287 then
5290 declare
5291 I : Interp_Index;
5292 It : Interp;
5294 begin
5295 Get_First_Interp (Arg, I, It);
5297 while Present (It.Nam) loop
5299 if Base_Type (Etype (It.Nam)) = Base_Type (Typ)
5300 or else Base_Type (Etype (It.Nam)) =
5301 Base_Type (Component_Type (Typ))
5302 then
5303 Error_Msg_Sloc := Sloc (It.Nam);
5305 end if;
5307 Get_Next_Interp (I, It);
5308 end loop;
5309 end;
5310 end if;
5312 Resolve (Arg, Component_Type (Typ));
5314 if Nkind (Arg) = N_String_Literal then
5315 Set_Etype (Arg, Component_Type (Typ));
5316 end if;
5318 if Arg = Left_Opnd (N) then
5319 Set_Is_Component_Left_Opnd (N);
5320 else
5321 Set_Is_Component_Right_Opnd (N);
5322 end if;
5323 end if;
5325 else
5326 Resolve (Arg, Btyp);
5327 end if;
5329 Check_Unset_Reference (Arg);
5330 end Resolve_Concatenation_Arg;
5332 -- Start of processing for Resolve_Op_Concat
5334 begin
5335 Set_Etype (N, Btyp);
5337 if Is_Limited_Composite (Btyp) then
5339 Explain_Limited_Type (Btyp, N);
5340 end if;
5342 -- If the operands are themselves concatenations, resolve them as
5343 -- such directly. This removes several layers of recursion and allows
5344 -- GNAT to handle larger multiple concatenations.
5346 if Nkind (Op1) = N_Op_Concat
5347 and then not Is_Array_Type (Component_Type (Typ))
5348 and then Entity (Op1) = Entity (N)
5349 then
5350 Resolve_Op_Concat (Op1, Typ);
5351 else
5352 Resolve_Concatenation_Arg
5353 (Op1, Is_Component_Left_Opnd (N));
5354 end if;
5356 if Nkind (Op2) = N_Op_Concat
5357 and then not Is_Array_Type (Component_Type (Typ))
5358 and then Entity (Op2) = Entity (N)
5359 then
5360 Resolve_Op_Concat (Op2, Typ);
5361 else
5362 Resolve_Concatenation_Arg
5363 (Op2, Is_Component_Right_Opnd (N));
5364 end if;
5366 Generate_Operator_Reference (N, Typ);
5368 if Is_String_Type (Typ) then
5369 Eval_Concatenation (N);
5370 end if;
5372 -- If this is not a static concatenation, but the result is a
5373 -- string type (and not an array of strings) insure that static
5374 -- string operands have their subtypes properly constructed.
5376 if Nkind (N) /= N_String_Literal
5377 and then Is_Character_Type (Component_Type (Typ))
5378 then
5379 Set_String_Literal_Subtype (Op1, Typ);
5380 Set_String_Literal_Subtype (Op2, Typ);
5381 end if;
5382 end Resolve_Op_Concat;
5384 ----------------------
5385 -- Resolve_Op_Expon --
5386 ----------------------
5388 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
5389 B_Typ : constant Entity_Id := Base_Type (Typ);
5391 begin
5392 -- Catch attempts to do fixed-point exponentation with universal
5393 -- operands, which is a case where the illegality is not caught
5394 -- during normal operator analysis.
5396 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
5398 return;
5399 end if;
5401 if Comes_From_Source (N)
5402 and then Ekind (Entity (N)) = E_Function
5403 and then Is_Imported (Entity (N))
5404 and then Is_Intrinsic_Subprogram (Entity (N))
5405 then
5406 Resolve_Intrinsic_Operator (N, Typ);
5407 return;
5408 end if;
5410 if Etype (Left_Opnd (N)) = Universal_Integer
5411 or else Etype (Left_Opnd (N)) = Universal_Real
5412 then
5413 Check_For_Visible_Operator (N, B_Typ);
5414 end if;
5416 -- We do the resolution using the base type, because intermediate values
5417 -- in expressions always are of the base type, not a subtype of it.
5419 Resolve (Left_Opnd (N), B_Typ);
5420 Resolve (Right_Opnd (N), Standard_Integer);
5422 Check_Unset_Reference (Left_Opnd (N));
5423 Check_Unset_Reference (Right_Opnd (N));
5425 Set_Etype (N, B_Typ);
5426 Generate_Operator_Reference (N, B_Typ);
5427 Eval_Op_Expon (N);
5429 -- Set overflow checking bit. Much cleverer code needed here eventually
5430 -- and perhaps the Resolve routines should be separated for the various
5431 -- arithmetic operations, since they will need different processing. ???
5433 if Nkind (N) in N_Op then
5434 if not Overflow_Checks_Suppressed (Etype (N)) then
5435 Enable_Overflow_Check (N);
5436 end if;
5437 end if;
5438 end Resolve_Op_Expon;
5440 --------------------
5441 -- Resolve_Op_Not --
5442 --------------------
5444 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
5445 B_Typ : Entity_Id;
5447 function Parent_Is_Boolean return Boolean;
5448 -- This function determines if the parent node is a boolean operator
5449 -- or operation (comparison op, membership test, or short circuit form)
5450 -- and the not in question is the left operand of this operation.
5451 -- Note that if the not is in parens, then false is returned.
5453 function Parent_Is_Boolean return Boolean is
5454 begin
5455 if Paren_Count (N) /= 0 then
5456 return False;
5458 else
5459 case Nkind (Parent (N)) is
5460 when N_Op_And |
5461 N_Op_Eq |
5462 N_Op_Ge |
5463 N_Op_Gt |
5464 N_Op_Le |
5465 N_Op_Lt |
5466 N_Op_Ne |
5467 N_Op_Or |
5468 N_Op_Xor |
5469 N_In |
5470 N_Not_In |
5471 N_And_Then |
5472 N_Or_Else =>
5474 return Left_Opnd (Parent (N)) = N;
5476 when others =>
5477 return False;
5478 end case;
5479 end if;
5480 end Parent_Is_Boolean;
5482 -- Start of processing for Resolve_Op_Not
5484 begin
5485 -- Predefined operations on scalar types yield the base type. On
5486 -- the other hand, logical operations on arrays yield the type of
5487 -- the arguments (and the context).
5489 if Is_Array_Type (Typ) then
5490 B_Typ := Typ;
5491 else
5492 B_Typ := Base_Type (Typ);
5493 end if;
5495 if not Valid_Boolean_Arg (Typ) then
5497 Set_Etype (N, Any_Type);
5498 return;
5500 elsif Typ = Universal_Integer or else Typ = Any_Modular then
5501 if Parent_Is_Boolean then
5502 Error_Msg_N
5504 Right_Opnd (N));
5505 else
5506 Error_Msg_N
5508 end if;
5510 Set_Etype (N, Any_Type);
5511 return;
5513 else
5514 if not Is_Boolean_Type (Typ)
5515 and then Parent_Is_Boolean
5516 then
5518 end if;
5520 Resolve (Right_Opnd (N), B_Typ);
5521 Check_Unset_Reference (Right_Opnd (N));
5522 Set_Etype (N, B_Typ);
5523 Generate_Operator_Reference (N, B_Typ);
5524 Eval_Op_Not (N);
5525 end if;
5526 end Resolve_Op_Not;
5528 -----------------------------
5529 -- Resolve_Operator_Symbol --
5530 -----------------------------
5532 -- Nothing to be done, all resolved already
5534 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
5535 pragma Warnings (Off, N);
5536 pragma Warnings (Off, Typ);
5538 begin
5539 null;
5540 end Resolve_Operator_Symbol;
5542 ----------------------------------
5543 -- Resolve_Qualified_Expression --
5544 ----------------------------------
5546 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
5547 pragma Warnings (Off, Typ);
5549 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
5550 Expr : constant Node_Id := Expression (N);
5552 begin
5553 Resolve (Expr, Target_Typ);
5555 -- A qualified expression requires an exact match of the type,
5556 -- class-wide matching is not allowed.
5558 if Is_Class_Wide_Type (Target_Typ)
5559 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
5560 then
5561 Wrong_Type (Expr, Target_Typ);
5562 end if;
5564 -- If the target type is unconstrained, then we reset the type of
5565 -- the result from the type of the expression. For other cases, the
5566 -- actual subtype of the expression is the target type.
5568 if Is_Composite_Type (Target_Typ)
5569 and then not Is_Constrained (Target_Typ)
5570 then
5571 Set_Etype (N, Etype (Expr));
5572 end if;
5574 Eval_Qualified_Expression (N);
5575 end Resolve_Qualified_Expression;
5577 -------------------
5578 -- Resolve_Range --
5579 -------------------
5581 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
5582 L : constant Node_Id := Low_Bound (N);
5583 H : constant Node_Id := High_Bound (N);
5585 begin
5586 Set_Etype (N, Typ);
5587 Resolve (L, Typ);
5588 Resolve (H, Typ);
5590 Check_Unset_Reference (L);
5591 Check_Unset_Reference (H);
5593 -- We have to check the bounds for being within the base range as
5594 -- required for a non-static context. Normally this is automatic
5595 -- and done as part of evaluating expressions, but the N_Range
5596 -- node is an exception, since in GNAT we consider this node to
5597 -- be a subexpression, even though in Ada it is not. The circuit
5598 -- in Sem_Eval could check for this, but that would put the test
5599 -- on the main evaluation path for expressions.
5601 Check_Non_Static_Context (L);
5602 Check_Non_Static_Context (H);
5604 -- If bounds are static, constant-fold them, so size computations
5605 -- are identical between front-end and back-end. Do not perform this
5606 -- transformation while analyzing generic units, as type information
5607 -- would then be lost when reanalyzing the constant node in the
5608 -- instance.
5610 if Is_Discrete_Type (Typ) and then Expander_Active then
5611 if Is_OK_Static_Expression (L) then
5612 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
5613 end if;
5615 if Is_OK_Static_Expression (H) then
5616 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
5617 end if;
5618 end if;
5619 end Resolve_Range;
5621 --------------------------
5622 -- Resolve_Real_Literal --
5623 --------------------------
5625 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
5626 Actual_Typ : constant Entity_Id := Etype (N);
5628 begin
5629 -- Special processing for fixed-point literals to make sure that the
5630 -- value is an exact multiple of small where this is required. We
5631 -- skip this for the universal real case, and also for generic types.
5633 if Is_Fixed_Point_Type (Typ)
5634 and then Typ /= Universal_Fixed
5635 and then Typ /= Any_Fixed
5636 and then not Is_Generic_Type (Typ)
5637 then
5638 declare
5639 Val : constant Ureal := Realval (N);
5640 Cintr : constant Ureal := Val / Small_Value (Typ);
5641 Cint : constant Uint := UR_Trunc (Cintr);
5642 Den : constant Uint := Norm_Den (Cintr);
5643 Stat : Boolean;
5645 begin
5646 -- Case of literal is not an exact multiple of the Small
5648 if Den /= 1 then
5650 -- For a source program literal for a decimal fixed-point
5651 -- type, this is statically illegal (RM 4.9(36)).
5653 if Is_Decimal_Fixed_Point_Type (Typ)
5654 and then Actual_Typ = Universal_Real
5655 and then Comes_From_Source (N)
5656 then
5658 end if;
5660 -- Replace literal by a value that is the exact representation
5661 -- of a value of the type, i.e. a multiple of the small value,
5662 -- by truncation, since Machine_Rounds is false for all GNAT
5663 -- fixed-point types (RM 4.9(38)).
5665 Stat := Is_Static_Expression (N);
5666 Rewrite (N,
5667 Make_Real_Literal (Sloc (N),
5668 Realval => Small_Value (Typ) * Cint));
5670 Set_Is_Static_Expression (N, Stat);
5671 end if;
5673 -- In all cases, set the corresponding integer field
5675 Set_Corresponding_Integer_Value (N, Cint);
5676 end;
5677 end if;
5679 -- Now replace the actual type by the expected type as usual
5681 Set_Etype (N, Typ);
5682 Eval_Real_Literal (N);
5683 end Resolve_Real_Literal;
5685 -----------------------
5686 -- Resolve_Reference --
5687 -----------------------
5689 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
5690 P : constant Node_Id := Prefix (N);
5692 begin
5693 -- Replace general access with specific type
5695 if Ekind (Etype (N)) = E_Allocator_Type then
5696 Set_Etype (N, Base_Type (Typ));
5697 end if;
5699 Resolve (P, Designated_Type (Etype (N)));
5701 -- If we are taking the reference of a volatile entity, then treat
5702 -- it as a potential modification of this entity. This is much too
5703 -- conservative, but is necessary because remove side effects can
5704 -- result in transformations of normal assignments into reference
5705 -- sequences that otherwise fail to notice the modification.
5707 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
5708 Note_Possible_Modification (P);
5709 end if;
5710 end Resolve_Reference;
5712 --------------------------------
5713 -- Resolve_Selected_Component --
5714 --------------------------------
5716 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
5717 Comp : Entity_Id;
5718 Comp1 : Entity_Id := Empty; -- prevent junk warning
5719 P : constant Node_Id := Prefix (N);
5720 S : constant Node_Id := Selector_Name (N);
5721 T : Entity_Id := Etype (P);
5722 I : Interp_Index;
5723 I1 : Interp_Index := 0; -- prevent junk warning
5724 It : Interp;
5725 It1 : Interp;
5726 Found : Boolean;
5728 function Init_Component return Boolean;
5729 -- Check whether this is the initialization of a component within an
5730 -- init proc (by assignment or call to another init proc). If true,
5731 -- there is no need for a discriminant check.
5733 --------------------
5734 -- Init_Component --
5735 --------------------
5737 function Init_Component return Boolean is
5738 begin
5739 return Inside_Init_Proc
5740 and then Nkind (Prefix (N)) = N_Identifier
5741 and then Chars (Prefix (N)) = Name_uInit
5742 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
5743 end Init_Component;
5745 -- Start of processing for Resolve_Selected_Component
5747 begin
5748 if Is_Overloaded (P) then
5750 -- Use the context type to select the prefix that has a selector
5751 -- of the correct name and type.
5753 Found := False;
5754 Get_First_Interp (P, I, It);
5756 Search : while Present (It.Typ) loop
5757 if Is_Access_Type (It.Typ) then
5758 T := Designated_Type (It.Typ);
5759 else
5760 T := It.Typ;
5761 end if;
5763 if Is_Record_Type (T) then
5764 Comp := First_Entity (T);
5766 while Present (Comp) loop
5768 if Chars (Comp) = Chars (S)
5769 and then Covers (Etype (Comp), Typ)
5770 then
5771 if not Found then
5772 Found := True;
5773 I1 := I;
5774 It1 := It;
5775 Comp1 := Comp;
5777 else
5778 It := Disambiguate (P, I1, I, Any_Type);
5780 if It = No_Interp then
5781 Error_Msg_N
5783 Set_Etype (N, Typ);
5784 return;
5786 else
5787 It1 := It;
5789 if Scope (Comp1) /= It1.Typ then
5791 -- Resolution chooses the new interpretation.
5792 -- Find the component with the right name.
5794 Comp1 := First_Entity (It1.Typ);
5796 while Present (Comp1)
5797 and then Chars (Comp1) /= Chars (S)
5798 loop
5799 Comp1 := Next_Entity (Comp1);
5800 end loop;
5801 end if;
5803 exit Search;
5804 end if;
5805 end if;
5806 end if;
5808 Comp := Next_Entity (Comp);
5809 end loop;
5811 end if;
5813 Get_Next_Interp (I, It);
5814 end loop Search;
5816 Resolve (P, It1.Typ);
5817 Set_Etype (N, Typ);
5818 Set_Entity (S, Comp1);
5820 else
5821 -- Resolve prefix with its type
5823 Resolve (P, T);
5824 end if;
5826 -- Deal with access type case
5828 if Is_Access_Type (Etype (P)) then
5829 Apply_Access_Check (N);
5830 T := Designated_Type (Etype (P));
5831 else
5832 T := Etype (P);
5833 end if;
5835 if Has_Discriminants (T)
5836 and then (Ekind (Entity (S)) = E_Component
5837 or else
5838 Ekind (Entity (S)) = E_Discriminant)
5839 and then Present (Original_Record_Component (Entity (S)))
5840 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
5841 and then Present (Discriminant_Checking_Func
5842 (Original_Record_Component (Entity (S))))
5843 and then not Discriminant_Checks_Suppressed (T)
5844 and then not Init_Component
5845 then
5846 Set_Do_Discriminant_Check (N);
5847 end if;
5849 if Ekind (Entity (S)) = E_Void then
5851 end if;
5853 -- If the prefix is a record conversion, this may be a renamed
5854 -- discriminant whose bounds differ from those of the original
5855 -- one, so we must ensure that a range check is performed.
5857 if Nkind (P) = N_Type_Conversion
5858 and then Ekind (Entity (S)) = E_Discriminant
5859 and then Is_Discrete_Type (Typ)
5860 then
5861 Set_Etype (N, Base_Type (Typ));
5862 end if;
5864 -- Note: No Eval processing is required, because the prefix is of a
5865 -- record type, or protected type, and neither can possibly be static.
5867 end Resolve_Selected_Component;
5869 -------------------
5870 -- Resolve_Shift --
5871 -------------------
5873 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
5874 B_Typ : constant Entity_Id := Base_Type (Typ);
5875 L : constant Node_Id := Left_Opnd (N);
5876 R : constant Node_Id := Right_Opnd (N);
5878 begin
5879 -- We do the resolution using the base type, because intermediate values
5880 -- in expressions always are of the base type, not a subtype of it.
5882 Resolve (L, B_Typ);
5883 Resolve (R, Standard_Natural);
5885 Check_Unset_Reference (L);
5886 Check_Unset_Reference (R);
5888 Set_Etype (N, B_Typ);
5889 Generate_Operator_Reference (N, B_Typ);
5890 Eval_Shift (N);
5891 end Resolve_Shift;
5893 ---------------------------
5894 -- Resolve_Short_Circuit --
5895 ---------------------------
5897 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
5898 B_Typ : constant Entity_Id := Base_Type (Typ);
5899 L : constant Node_Id := Left_Opnd (N);
5900 R : constant Node_Id := Right_Opnd (N);
5902 begin
5903 Resolve (L, B_Typ);
5904 Resolve (R, B_Typ);
5906 Check_Unset_Reference (L);
5907 Check_Unset_Reference (R);
5909 Set_Etype (N, B_Typ);
5910 Eval_Short_Circuit (N);
5911 end Resolve_Short_Circuit;
5913 -------------------
5914 -- Resolve_Slice --
5915 -------------------
5917 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
5918 Name : constant Node_Id := Prefix (N);
5919 Drange : constant Node_Id := Discrete_Range (N);
5920 Array_Type : Entity_Id := Empty;
5921 Index : Node_Id;
5923 begin
5924 if Is_Overloaded (Name) then
5926 -- Use the context type to select the prefix that yields the
5927 -- correct array type.
5929 declare
5930 I : Interp_Index;
5931 I1 : Interp_Index := 0;
5932 It : Interp;
5933 P : constant Node_Id := Prefix (N);
5934 Found : Boolean := False;
5936 begin
5937 Get_First_Interp (P, I, It);
5939 while Present (It.Typ) loop
5941 if (Is_Array_Type (It.Typ)
5942 and then Covers (Typ, It.Typ))
5943 or else (Is_Access_Type (It.Typ)
5944 and then Is_Array_Type (Designated_Type (It.Typ))
5945 and then Covers (Typ, Designated_Type (It.Typ)))
5946 then
5947 if Found then
5948 It := Disambiguate (P, I1, I, Any_Type);
5950 if It = No_Interp then
5952 Set_Etype (N, Typ);
5953 return;
5954 else
5955 Found := True;
5956 Array_Type := It.Typ;
5957 I1 := I;
5958 end if;
5959 else
5960 Found := True;
5961 Array_Type := It.Typ;
5962 I1 := I;
5963 end if;
5964 end if;
5966 Get_Next_Interp (I, It);
5967 end loop;
5968 end;
5970 else
5971 Array_Type := Etype (Name);
5972 end if;
5974 Resolve (Name, Array_Type);
5976 if Is_Access_Type (Array_Type) then
5977 Apply_Access_Check (N);
5978 Array_Type := Designated_Type (Array_Type);
5980 elsif Is_Entity_Name (Name)
5981 or else (Nkind (Name) = N_Function_Call
5982 and then not Is_Constrained (Etype (Name)))
5983 then
5984 Array_Type := Get_Actual_Subtype (Name);
5985 end if;
5987 -- If name was overloaded, set slice type correctly now
5989 Set_Etype (N, Array_Type);
5991 -- If the range is specified by a subtype mark, no resolution
5992 -- is necessary.
5994 if not Is_Entity_Name (Drange) then
5995 Index := First_Index (Array_Type);
5996 Resolve (Drange, Base_Type (Etype (Index)));
5998 if Nkind (Drange) = N_Range then
5999 Apply_Range_Check (Drange, Etype (Index));
6000 end if;
6001 end if;
6003 Set_Slice_Subtype (N);
6004 Eval_Slice (N);
6005 end Resolve_Slice;
6007 ----------------------------
6008 -- Resolve_String_Literal --
6009 ----------------------------
6011 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
6012 C_Typ : constant Entity_Id := Component_Type (Typ);
6013 R_Typ : constant Entity_Id := Root_Type (C_Typ);
6014 Loc : constant Source_Ptr := Sloc (N);
6015 Str : constant String_Id := Strval (N);
6016 Strlen : constant Nat := String_Length (Str);
6017 Subtype_Id : Entity_Id;
6018 Need_Check : Boolean;
6020 begin
6021 -- For a string appearing in a concatenation, defer creation of the
6022 -- string_literal_subtype until the end of the resolution of the
6023 -- concatenation, because the literal may be constant-folded away.
6024 -- This is a useful optimization for long concatenation expressions.
6026 -- If the string is an aggregate built for a single character (which
6027 -- happens in a non-static context) or a is null string to which special
6028 -- checks may apply, we build the subtype. Wide strings must also get
6029 -- a string subtype if they come from a one character aggregate. Strings
6030 -- generated by attributes might be static, but it is often hard to
6031 -- determine whether the enclosing context is static, so we generate
6032 -- subtypes for them as well, thus losing some rarer optimizations ???
6033 -- Same for strings that come from a static conversion.
6035 Need_Check :=
6036 (Strlen = 0 and then Typ /= Standard_String)
6037 or else Nkind (Parent (N)) /= N_Op_Concat
6038 or else (N /= Left_Opnd (Parent (N))
6039 and then N /= Right_Opnd (Parent (N)))
6040 or else (Typ = Standard_Wide_String
6041 and then Nkind (Original_Node (N)) /= N_String_Literal);
6043 -- If the resolving type is itself a string literal subtype, we
6044 -- can just reuse it, since there is no point in creating another.
6046 if Ekind (Typ) = E_String_Literal_Subtype then
6047 Subtype_Id := Typ;
6049 elsif Nkind (Parent (N)) = N_Op_Concat
6050 and then not Need_Check
6051 and then Nkind (Original_Node (N)) /= N_Character_Literal
6052 and then Nkind (Original_Node (N)) /= N_Attribute_Reference
6053 and then Nkind (Original_Node (N)) /= N_Qualified_Expression
6054 and then Nkind (Original_Node (N)) /= N_Type_Conversion
6055 then
6056 Subtype_Id := Typ;
6058 -- Otherwise we must create a string literal subtype. Note that the
6059 -- whole idea of string literal subtypes is simply to avoid the need
6060 -- for building a full fledged array subtype for each literal.
6061 else
6062 Set_String_Literal_Subtype (N, Typ);
6063 Subtype_Id := Etype (N);
6064 end if;
6066 if Nkind (Parent (N)) /= N_Op_Concat
6067 or else Need_Check
6068 then
6069 Set_Etype (N, Subtype_Id);
6070 Eval_String_Literal (N);
6071 end if;
6073 if Is_Limited_Composite (Typ)
6074 or else Is_Private_Composite (Typ)
6075 then
6077 Set_Etype (N, Any_Type);
6078 return;
6079 end if;
6081 -- The validity of a null string has been checked in the
6082 -- call to Eval_String_Literal.
6084 if Strlen = 0 then
6085 return;
6087 -- Always accept string literal with component type Any_Character,
6088 -- which occurs in error situations and in comparisons of literals,
6089 -- both of which should accept all literals.
6091 elsif R_Typ = Any_Character then
6092 return;
6094 -- If the type is bit-packed, then we always tranform the string
6095 -- literal into a full fledged aggregate.
6097 elsif Is_Bit_Packed_Array (Typ) then
6098 null;
6100 -- Deal with cases of Wide_String and String
6102 else
6103 -- For Standard.Wide_String, or any other type whose component
6104 -- type is Standard.Wide_Character, we know that all the
6105 -- characters in the string must be acceptable, since the parser
6106 -- accepted the characters as valid character literals.
6108 if R_Typ = Standard_Wide_Character then
6109 null;
6111 -- For the case of Standard.String, or any other type whose
6112 -- component type is Standard.Character, we must make sure that
6113 -- there are no wide characters in the string, i.e. that it is
6114 -- entirely composed of characters in range of type String.
6116 -- If the string literal is the result of a static concatenation,
6117 -- the test has already been performed on the components, and need
6118 -- not be repeated.
6120 elsif R_Typ = Standard_Character
6121 and then Nkind (Original_Node (N)) /= N_Op_Concat
6122 then
6123 for J in 1 .. Strlen loop
6124 if not In_Character_Range (Get_String_Char (Str, J)) then
6126 -- If we are out of range, post error. This is one of the
6127 -- very few places that we place the flag in the middle of
6128 -- a token, right under the offending wide character.
6130 Error_Msg
6132 Source_Ptr (Int (Loc) + J));
6133 return;
6134 end if;
6135 end loop;
6137 -- If the root type is not a standard character, then we will convert
6138 -- the string into an aggregate and will let the aggregate code do
6139 -- the checking.
6141 else
6142 null;
6144 end if;
6146 -- See if the component type of the array corresponding to the
6147 -- string has compile time known bounds. If yes we can directly
6148 -- check whether the evaluation of the string will raise constraint
6149 -- error. Otherwise we need to transform the string literal into
6150 -- the corresponding character aggregate and let the aggregate
6151 -- code do the checking.
6153 if R_Typ = Standard_Wide_Character
6154 or else R_Typ = Standard_Character
6155 then
6156 -- Check for the case of full range, where we are definitely OK
6158 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
6159 return;
6160 end if;
6162 -- Here the range is not the complete base type range, so check
6164 declare
6165 Comp_Typ_Lo : constant Node_Id :=
6166 Type_Low_Bound (Component_Type (Typ));
6167 Comp_Typ_Hi : constant Node_Id :=
6168 Type_High_Bound (Component_Type (Typ));
6170 Char_Val : Uint;
6172 begin
6173 if Compile_Time_Known_Value (Comp_Typ_Lo)
6174 and then Compile_Time_Known_Value (Comp_Typ_Hi)
6175 then
6176 for J in 1 .. Strlen loop
6177 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
6179 if Char_Val < Expr_Value (Comp_Typ_Lo)
6180 or else Char_Val > Expr_Value (Comp_Typ_Hi)
6181 then
6182 Apply_Compile_Time_Constraint_Error
6184 Loc => Source_Ptr (Int (Loc) + J));
6185 end if;
6186 end loop;
6188 return;
6189 end if;
6190 end;
6191 end if;
6192 end if;
6194 -- If we got here we meed to transform the string literal into the
6195 -- equivalent qualified positional array aggregate. This is rather
6196 -- heavy artillery for this situation, but it is hard work to avoid.
6198 declare
6199 Lits : constant List_Id := New_List;
6200 P : Source_Ptr := Loc + 1;
6201 C : Char_Code;
6203 begin
6204 -- Build the character literals, we give them source locations
6205 -- that correspond to the string positions, which is a bit tricky
6206 -- given the possible presence of wide character escape sequences.
6208 for J in 1 .. Strlen loop
6209 C := Get_String_Char (Str, J);
6210 Set_Character_Literal_Name (C);
6212 Append_To (Lits,
6213 Make_Character_Literal (P, Name_Find, C));
6215 if In_Character_Range (C) then
6216 P := P + 1;
6218 -- Should we have a call to Skip_Wide here ???
6219 -- ??? else
6220 -- Skip_Wide (P);
6222 end if;
6223 end loop;
6225 Rewrite (N,
6226 Make_Qualified_Expression (Loc,
6227 Subtype_Mark => New_Reference_To (Typ, Loc),
6228 Expression =>
6229 Make_Aggregate (Loc, Expressions => Lits)));
6231 Analyze_And_Resolve (N, Typ);
6232 end;
6233 end Resolve_String_Literal;
6235 -----------------------------
6236 -- Resolve_Subprogram_Info --
6237 -----------------------------
6239 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
6240 begin
6241 Set_Etype (N, Typ);
6242 end Resolve_Subprogram_Info;
6244 -----------------------------
6245 -- Resolve_Type_Conversion --
6246 -----------------------------
6248 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
6249 Target_Type : constant Entity_Id := Etype (N);
6250 Conv_OK : constant Boolean := Conversion_OK (N);
6251 Operand : Node_Id;
6252 Opnd_Type : Entity_Id;
6253 Rop : Node_Id;
6254 Orig_N : Node_Id;
6255 Orig_T : Node_Id;
6257 begin
6258 Operand := Expression (N);
6260 if not Conv_OK
6261 and then not Valid_Conversion (N, Target_Type, Operand)
6262 then
6263 return;
6264 end if;
6266 if Etype (Operand) = Any_Fixed then
6268 -- Mixed-mode operation involving a literal. Context must be a fixed
6269 -- type which is applied to the literal subsequently.
6271 if Is_Fixed_Point_Type (Typ) then
6272 Set_Etype (Operand, Universal_Real);
6274 elsif Is_Numeric_Type (Typ)
6275 and then (Nkind (Operand) = N_Op_Multiply
6276 or else Nkind (Operand) = N_Op_Divide)
6277 and then (Etype (Right_Opnd (Operand)) = Universal_Real
6278 or else Etype (Left_Opnd (Operand)) = Universal_Real)
6279 then
6280 if Unique_Fixed_Point_Type (N) = Any_Type then
6281 return; -- expression is ambiguous.
6282 else
6283 Set_Etype (Operand, Standard_Duration);
6284 end if;
6286 if Etype (Right_Opnd (Operand)) = Universal_Real then
6287 Rop := New_Copy_Tree (Right_Opnd (Operand));
6288 else
6289 Rop := New_Copy_Tree (Left_Opnd (Operand));
6290 end if;
6292 Resolve (Rop, Standard_Long_Long_Float);
6294 if Realval (Rop) /= Ureal_0
6295 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
6296 then
6298 Rop);
6300 end if;
6302 elsif Is_Numeric_Type (Typ)
6303 and then Nkind (Operand) in N_Op
6304 and then Unique_Fixed_Point_Type (N) /= Any_Type
6305 then
6306 Set_Etype (Operand, Standard_Duration);
6308 else
6310 Set_Etype (Operand, Any_Type);
6311 return;
6312 end if;
6313 end if;
6315 Opnd_Type := Etype (Operand);
6316 Resolve (Operand);
6318 -- Note: we do the Eval_Type_Conversion call before applying the
6319 -- required checks for a subtype conversion. This is important,
6320 -- since both are prepared under certain circumstances to change
6321 -- the type conversion to a constraint error node, but in the case
6322 -- of Eval_Type_Conversion this may reflect an illegality in the
6323 -- static case, and we would miss the illegality (getting only a
6324 -- warning message), if we applied the type conversion checks first.
6326 Eval_Type_Conversion (N);
6328 -- If after evaluation, we still have a type conversion, then we
6329 -- may need to apply checks required for a subtype conversion.
6331 -- Skip these type conversion checks if universal fixed operands
6332 -- operands involved, since range checks are handled separately for
6333 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
6335 if Nkind (N) = N_Type_Conversion
6336 and then not Is_Generic_Type (Root_Type (Target_Type))
6337 and then Target_Type /= Universal_Fixed
6338 and then Opnd_Type /= Universal_Fixed
6339 then
6340 Apply_Type_Conversion_Checks (N);
6341 end if;
6343 -- Issue warning for conversion of simple object to its own type
6344 -- We have to test the original nodes, since they may have been
6345 -- rewritten by various optimizations.
6347 Orig_N := Original_Node (N);
6349 if Warn_On_Redundant_Constructs
6350 and then Comes_From_Source (Orig_N)
6351 and then Nkind (Orig_N) = N_Type_Conversion
6352 and then not In_Instance
6353 then
6354 Orig_N := Original_Node (Expression (Orig_N));
6355 Orig_T := Target_Type;
6357 -- If the node is part of a larger expression, the Target_Type
6358 -- may not be the original type of the node if the context is a
6359 -- condition. Recover original type to see if conversion is needed.
6361 if Is_Boolean_Type (Orig_T)
6362 and then Nkind (Parent (N)) in N_Op
6363 then
6364 Orig_T := Etype (Parent (N));
6365 end if;
6367 if Is_Entity_Name (Orig_N)
6368 and then Etype (Entity (Orig_N)) = Orig_T
6369 then
6370 Error_Msg_NE
6372 end if;
6373 end if;
6374 end Resolve_Type_Conversion;
6376 ----------------------
6377 -- Resolve_Unary_Op --
6378 ----------------------
6380 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
6381 B_Typ : constant Entity_Id := Base_Type (Typ);
6382 R : constant Node_Id := Right_Opnd (N);
6383 OK : Boolean;
6384 Lo : Uint;
6385 Hi : Uint;
6387 begin
6388 -- Generate warning for expressions like abs (x mod 2)
6390 if Warn_On_Redundant_Constructs
6391 and then Nkind (N) = N_Op_Abs
6392 then
6393 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
6395 if OK and then Hi >= Lo and then Lo >= 0 then
6396 Error_Msg_N
6398 end if;
6399 end if;
6401 -- Generate warning for expressions like -5 mod 3
6403 if Paren_Count (N) = 0
6404 and then Nkind (N) = N_Op_Minus
6405 and then Nkind (Right_Opnd (N)) = N_Op_Mod
6406 and then Comes_From_Source (N)
6407 then
6408 Error_Msg_N
6410 end if;
6412 if Comes_From_Source (N)
6413 and then Ekind (Entity (N)) = E_Function
6414 and then Is_Imported (Entity (N))
6415 and then Is_Intrinsic_Subprogram (Entity (N))
6416 then
6417 Resolve_Intrinsic_Unary_Operator (N, Typ);
6418 return;
6419 end if;
6421 if Etype (R) = Universal_Integer
6422 or else Etype (R) = Universal_Real
6423 then
6424 Check_For_Visible_Operator (N, B_Typ);
6425 end if;
6427 Set_Etype (N, B_Typ);
6428 Resolve (R, B_Typ);
6430 Check_Unset_Reference (R);
6431 Generate_Operator_Reference (N, B_Typ);
6432 Eval_Unary_Op (N);
6434 -- Set overflow checking bit. Much cleverer code needed here eventually
6435 -- and perhaps the Resolve routines should be separated for the various
6436 -- arithmetic operations, since they will need different processing ???
6438 if Nkind (N) in N_Op then
6439 if not Overflow_Checks_Suppressed (Etype (N)) then
6440 Enable_Overflow_Check (N);
6441 end if;
6442 end if;
6443 end Resolve_Unary_Op;
6445 ----------------------------------
6446 -- Resolve_Unchecked_Expression --
6447 ----------------------------------
6449 procedure Resolve_Unchecked_Expression
6450 (N : Node_Id;
6451 Typ : Entity_Id)
6452 is
6453 begin
6454 Resolve (Expression (N), Typ, Suppress => All_Checks);
6455 Set_Etype (N, Typ);
6456 end Resolve_Unchecked_Expression;
6458 ---------------------------------------
6459 -- Resolve_Unchecked_Type_Conversion --
6460 ---------------------------------------
6462 procedure Resolve_Unchecked_Type_Conversion
6463 (N : Node_Id;
6464 Typ : Entity_Id)
6465 is
6466 pragma Warnings (Off, Typ);
6468 Operand : constant Node_Id := Expression (N);
6469 Opnd_Type : constant Entity_Id := Etype (Operand);
6471 begin
6472 -- Resolve operand using its own type.
6474 Resolve (Operand, Opnd_Type);
6475 Eval_Unchecked_Conversion (N);
6477 end Resolve_Unchecked_Type_Conversion;
6479 ------------------------------
6480 -- Rewrite_Operator_As_Call --
6481 ------------------------------
6483 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
6484 Loc : constant Source_Ptr := Sloc (N);
6485 Actuals : constant List_Id := New_List;
6486 New_N : Node_Id;
6488 begin
6489 if Nkind (N) in N_Binary_Op then
6490 Append (Left_Opnd (N), Actuals);
6491 end if;
6493 Append (Right_Opnd (N), Actuals);
6495 New_N :=
6496 Make_Function_Call (Sloc => Loc,
6497 Name => New_Occurrence_Of (Nam, Loc),
6498 Parameter_Associations => Actuals);
6500 Preserve_Comes_From_Source (New_N, N);
6501 Preserve_Comes_From_Source (Name (New_N), N);
6502 Rewrite (N, New_N);
6503 Set_Etype (N, Etype (Nam));
6504 end Rewrite_Operator_As_Call;
6506 ------------------------------
6507 -- Rewrite_Renamed_Operator --
6508 ------------------------------
6510 procedure Rewrite_Renamed_Operator
6511 (N : Node_Id;
6512 Op : Entity_Id;
6513 Typ : Entity_Id)
6514 is
6515 Nam : constant Name_Id := Chars (Op);
6516 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
6517 Op_Node : Node_Id;
6519 begin
6520 -- Rewrite the operator node using the real operator, not its
6521 -- renaming. Exclude user-defined intrinsic operations of the same
6522 -- name, which are treated separately and rewritten as calls.
6524 if Ekind (Op) /= E_Function
6525 or else Chars (N) /= Nam
6526 then
6527 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
6528 Set_Chars (Op_Node, Nam);
6529 Set_Etype (Op_Node, Etype (N));
6530 Set_Entity (Op_Node, Op);
6531 Set_Right_Opnd (Op_Node, Right_Opnd (N));
6533 -- Indicate that both the original entity and its renaming
6534 -- are referenced at this point.
6536 Generate_Reference (Entity (N), N);
6537 Generate_Reference (Op, N);
6539 if Is_Binary then
6540 Set_Left_Opnd (Op_Node, Left_Opnd (N));
6541 end if;
6543 Rewrite (N, Op_Node);
6545 -- If the context type is private, add the appropriate conversions
6546 -- so that the operator is applied to the full view. This is done
6547 -- in the routines that resolve intrinsic operators,
6549 if Is_Intrinsic_Subprogram (Op)
6550 and then Is_Private_Type (Typ)
6551 then
6552 case Nkind (N) is
6553 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
6554 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
6555 Resolve_Intrinsic_Operator (N, Typ);
6557 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
6558 Resolve_Intrinsic_Unary_Operator (N, Typ);
6560 when others =>
6561 Resolve (N, Typ);
6562 end case;
6563 end if;
6565 elsif Ekind (Op) = E_Function
6566 and then Is_Intrinsic_Subprogram (Op)
6567 then
6568 -- Operator renames a user-defined operator of the same name. Use
6569 -- the original operator in the node, which is the one that gigi
6570 -- knows about.
6572 Set_Entity (N, Op);
6573 Set_Is_Overloaded (N, False);
6574 end if;
6575 end Rewrite_Renamed_Operator;
6577 -----------------------
6578 -- Set_Slice_Subtype --
6579 -----------------------
6581 -- Build an implicit subtype declaration to represent the type delivered
6582 -- by the slice. This is an abbreviated version of an array subtype. We
6583 -- define an index subtype for the slice, using either the subtype name
6584 -- or the discrete range of the slice. To be consistent with index usage
6585 -- elsewhere, we create a list header to hold the single index. This list
6586 -- is not otherwise attached to the syntax tree.
6588 procedure Set_Slice_Subtype (N : Node_Id) is
6589 Loc : constant Source_Ptr := Sloc (N);
6590 Index_List : constant List_Id := New_List;
6591 Index : Node_Id;
6592 Index_Subtype : Entity_Id;
6593 Index_Type : Entity_Id;
6594 Slice_Subtype : Entity_Id;
6595 Drange : constant Node_Id := Discrete_Range (N);
6597 begin
6598 if Is_Entity_Name (Drange) then
6599 Index_Subtype := Entity (Drange);
6601 else
6602 -- We force the evaluation of a range. This is definitely needed in
6603 -- the renamed case, and seems safer to do unconditionally. Note in
6604 -- any case that since we will create and insert an Itype referring
6605 -- to this range, we must make sure any side effect removal actions
6606 -- are inserted before the Itype definition.
6608 if Nkind (Drange) = N_Range then
6609 Force_Evaluation (Low_Bound (Drange));
6610 Force_Evaluation (High_Bound (Drange));
6611 end if;
6613 Index_Type := Base_Type (Etype (Drange));
6615 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
6617 Set_Scalar_Range (Index_Subtype, Drange);
6618 Set_Etype (Index_Subtype, Index_Type);
6619 Set_Size_Info (Index_Subtype, Index_Type);
6620 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
6621 end if;
6623 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
6625 Index := New_Occurrence_Of (Index_Subtype, Loc);
6626 Set_Etype (Index, Index_Subtype);
6627 Append (Index, Index_List);
6629 Set_First_Index (Slice_Subtype, Index);
6630 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
6631 Set_Is_Constrained (Slice_Subtype, True);
6632 Init_Size_Align (Slice_Subtype);
6634 Check_Compile_Time_Size (Slice_Subtype);
6636 -- The Etype of the existing Slice node is reset to this slice
6637 -- subtype. Its bounds are obtained from its first index.
6639 Set_Etype (N, Slice_Subtype);
6641 -- In the packed case, this must be immediately frozen
6643 -- Couldn't we always freeze here??? and if we did, then the above
6644 -- call to Check_Compile_Time_Size could be eliminated, which would
6645 -- be nice, because then that routine could be made private to Freeze.
6647 if Is_Packed (Slice_Subtype) and not In_Default_Expression then
6648 Freeze_Itype (Slice_Subtype, N);
6649 end if;
6651 end Set_Slice_Subtype;
6653 --------------------------------
6654 -- Set_String_Literal_Subtype --
6655 --------------------------------
6657 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
6658 Subtype_Id : Entity_Id;
6660 begin
6661 if Nkind (N) /= N_String_Literal then
6662 return;
6663 else
6664 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
6665 end if;
6667 Set_String_Literal_Length (Subtype_Id, UI_From_Int
6668 (String_Length (Strval (N))));
6669 Set_Etype (Subtype_Id, Base_Type (Typ));
6670 Set_Is_Constrained (Subtype_Id);
6672 -- The low bound is set from the low bound of the corresponding
6673 -- index type. Note that we do not store the high bound in the
6674 -- string literal subtype, but it can be deduced if necssary
6675 -- from the length and the low bound.
6677 Set_String_Literal_Low_Bound
6678 (Subtype_Id, Type_Low_Bound (Etype (First_Index (Typ))));
6680 Set_Etype (N, Subtype_Id);
6681 end Set_String_Literal_Subtype;
6683 -----------------------------
6684 -- Unique_Fixed_Point_Type --
6685 -----------------------------
6687 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
6688 T1 : Entity_Id := Empty;
6689 T2 : Entity_Id;
6690 Item : Node_Id;
6691 Scop : Entity_Id;
6693 procedure Fixed_Point_Error;
6694 -- If true ambiguity, give details.
6696 procedure Fixed_Point_Error is
6697 begin
6701 end Fixed_Point_Error;
6703 begin
6704 -- The operations on Duration are visible, so Duration is always a
6705 -- possible interpretation.
6707 T1 := Standard_Duration;
6709 -- Look for fixed-point types in enclosing scopes.
6711 Scop := Current_Scope;
6712 while Scop /= Standard_Standard loop
6713 T2 := First_Entity (Scop);
6715 while Present (T2) loop
6716 if Is_Fixed_Point_Type (T2)
6717 and then Current_Entity (T2) = T2
6718 and then Scope (Base_Type (T2)) = Scop
6719 then
6720 if Present (T1) then
6721 Fixed_Point_Error;
6722 return Any_Type;
6723 else
6724 T1 := T2;
6725 end if;
6726 end if;
6728 Next_Entity (T2);
6729 end loop;
6731 Scop := Scope (Scop);
6732 end loop;
6734 -- Look for visible fixed type declarations in the context.
6736 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
6737 while Present (Item) loop
6738 if Nkind (Item) = N_With_Clause then
6739 Scop := Entity (Name (Item));
6740 T2 := First_Entity (Scop);
6742 while Present (T2) loop
6743 if Is_Fixed_Point_Type (T2)
6744 and then Scope (Base_Type (T2)) = Scop
6745 and then (Is_Potentially_Use_Visible (T2)
6746 or else In_Use (T2))
6747 then
6748 if Present (T1) then
6749 Fixed_Point_Error;
6750 return Any_Type;
6751 else
6752 T1 := T2;
6753 end if;
6754 end if;
6756 Next_Entity (T2);
6757 end loop;
6758 end if;
6760 Next (Item);
6761 end loop;
6763 if Nkind (N) = N_Real_Literal then
6766 else
6768 end if;
6770 return T1;
6771 end Unique_Fixed_Point_Type;
6773 ----------------------
6774 -- Valid_Conversion --
6775 ----------------------
6777 function Valid_Conversion
6778 (N : Node_Id;
6779 Target : Entity_Id;
6780 Operand : Node_Id) return Boolean
6781 is
6782 Target_Type : constant Entity_Id := Base_Type (Target);
6783 Opnd_Type : Entity_Id := Etype (Operand);
6785 function Conversion_Check
6786 (Valid : Boolean;
6787 Msg : String) return Boolean;
6788 -- Little routine to post Msg if Valid is False, returns Valid value
6790 function Valid_Tagged_Conversion
6791 (Target_Type : Entity_Id;
6792 Opnd_Type : Entity_Id) return Boolean;
6793 -- Specifically test for validity of tagged conversions
6795 ----------------------
6796 -- Conversion_Check --
6797 ----------------------
6799 function Conversion_Check
6800 (Valid : Boolean;
6801 Msg : String) return Boolean
6802 is
6803 begin
6804 if not Valid then
6805 Error_Msg_N (Msg, Operand);
6806 end if;
6808 return Valid;
6809 end Conversion_Check;
6811 -----------------------------
6812 -- Valid_Tagged_Conversion --
6813 -----------------------------
6815 function Valid_Tagged_Conversion
6816 (Target_Type : Entity_Id;
6817 Opnd_Type : Entity_Id) return Boolean
6818 is
6819 begin
6820 -- Upward conversions are allowed (RM 4.6(22)).
6822 if Covers (Target_Type, Opnd_Type)
6823 or else Is_Ancestor (Target_Type, Opnd_Type)
6824 then
6825 return True;
6827 -- Downward conversion are allowed if the operand is
6828 -- is class-wide (RM 4.6(23)).
6830 elsif Is_Class_Wide_Type (Opnd_Type)
6831 and then Covers (Opnd_Type, Target_Type)
6832 then
6833 return True;
6835 elsif Covers (Opnd_Type, Target_Type)
6836 or else Is_Ancestor (Opnd_Type, Target_Type)
6837 then
6838 return
6839 Conversion_Check (False,
6841 else
6842 Error_Msg_NE
6844 N, First_Subtype (Opnd_Type));
6845 return False;
6846 end if;
6847 end Valid_Tagged_Conversion;
6849 -- Start of processing for Valid_Conversion
6851 begin
6852 Check_Parameterless_Call (Operand);
6854 if Is_Overloaded (Operand) then
6855 declare
6856 I : Interp_Index;
6857 I1 : Interp_Index;
6858 It : Interp;
6859 It1 : Interp;
6860 N1 : Entity_Id;
6862 begin
6863 -- Remove procedure calls, which syntactically cannot appear
6864 -- in this context, but which cannot be removed by type checking,
6865 -- because the context does not impose a type.
6867 Get_First_Interp (Operand, I, It);
6869 while Present (It.Typ) loop
6871 if It.Typ = Standard_Void_Type then
6872 Remove_Interp (I);
6873 end if;
6875 Get_Next_Interp (I, It);
6876 end loop;
6878 Get_First_Interp (Operand, I, It);
6879 I1 := I;
6880 It1 := It;
6882 if No (It.Typ) then
6884 return False;
6885 end if;
6887 Get_Next_Interp (I, It);
6889 if Present (It.Typ) then
6890 N1 := It1.Nam;
6891 It1 := Disambiguate (Operand, I1, I, Any_Type);
6893 if It1 = No_Interp then
6896 Error_Msg_Sloc := Sloc (It.Nam);
6899 Error_Msg_Sloc := Sloc (N1);
6902 return False;
6903 end if;
6904 end if;
6906 Set_Etype (Operand, It1.Typ);
6907 Opnd_Type := It1.Typ;
6908 end;
6909 end if;
6911 if Chars (Current_Scope) = Name_Unchecked_Conversion then
6913 -- This check is dubious, what if there were a user defined
6914 -- scope whose name was Unchecked_Conversion ???
6916 return True;
6918 elsif Is_Numeric_Type (Target_Type) then
6919 if Opnd_Type = Universal_Fixed then
6920 return True;
6922 elsif (In_Instance or else In_Inlined_Body)
6923 and then not Comes_From_Source (N)
6924 then
6925 return True;
6927 else
6928 return Conversion_Check (Is_Numeric_Type (Opnd_Type),
6930 end if;
6932 elsif Is_Array_Type (Target_Type) then
6933 if not Is_Array_Type (Opnd_Type)
6934 or else Opnd_Type = Any_Composite
6935 or else Opnd_Type = Any_String
6936 then
6937 Error_Msg_N
6939 return False;
6941 elsif Number_Dimensions (Target_Type) /=
6942 Number_Dimensions (Opnd_Type)
6943 then
6944 Error_Msg_N
6946 return False;
6948 else
6949 declare
6950 Target_Index : Node_Id := First_Index (Target_Type);
6951 Opnd_Index : Node_Id := First_Index (Opnd_Type);
6953 Target_Index_Type : Entity_Id;
6954 Opnd_Index_Type : Entity_Id;
6956 Target_Comp_Type : constant Entity_Id :=
6957 Component_Type (Target_Type);
6958 Opnd_Comp_Type : constant Entity_Id :=
6959 Component_Type (Opnd_Type);
6961 begin
6962 while Present (Target_Index) and then Present (Opnd_Index) loop
6963 Target_Index_Type := Etype (Target_Index);
6964 Opnd_Index_Type := Etype (Opnd_Index);
6966 if not (Is_Integer_Type (Target_Index_Type)
6967 and then Is_Integer_Type (Opnd_Index_Type))
6968 and then (Root_Type (Target_Index_Type)
6969 /= Root_Type (Opnd_Index_Type))
6970 then
6971 Error_Msg_N
6973 Operand);
6974 return False;
6975 end if;
6977 Next_Index (Target_Index);
6978 Next_Index (Opnd_Index);
6979 end loop;
6981 if Base_Type (Target_Comp_Type) /=
6982 Base_Type (Opnd_Comp_Type)
6983 then
6984 Error_Msg_N
6986 Operand);
6987 return False;
6989 elsif
6990 Is_Constrained (Target_Comp_Type)
6991 /= Is_Constrained (Opnd_Comp_Type)
6992 or else not Subtypes_Statically_Match
6993 (Target_Comp_Type, Opnd_Comp_Type)
6994 then
6995 Error_Msg_N
6997 return False;
6999 end if;
7000 end;
7001 end if;
7003 return True;
7005 elsif (Ekind (Target_Type) = E_General_Access_Type
7006 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
7007 and then
7008 Conversion_Check
7009 (Is_Access_Type (Opnd_Type)
7010 and then Ekind (Opnd_Type) /=
7011 E_Access_Subprogram_Type
7012 and then Ekind (Opnd_Type) /=
7013 E_Access_Protected_Subprogram_Type,
7015 then
7016 if Is_Access_Constant (Opnd_Type)
7017 and then not Is_Access_Constant (Target_Type)
7018 then
7019 Error_Msg_N
7021 return False;
7022 end if;
7024 -- Check the static accessibility rule of 4.6(17). Note that
7025 -- the check is not enforced when within an instance body, since
7026 -- the RM requires such cases to be caught at run time.
7028 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
7029 if Type_Access_Level (Opnd_Type)
7030 > Type_Access_Level (Target_Type)
7031 then
7032 -- In an instance, this is a run-time check, but one we
7033 -- know will fail, so generate an appropriate warning.
7034 -- The raise will be generated by Expand_N_Type_Conversion.
7036 if In_Instance_Body then
7037 Error_Msg_N
7039 Operand);
7040 Error_Msg_N
7043 else
7044 Error_Msg_N
7046 Operand);
7047 return False;
7048 end if;
7050 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type then
7052 -- When the operand is a selected access discriminant
7053 -- the check needs to be made against the level of the
7054 -- object denoted by the prefix of the selected name.
7055 -- (Object_Access_Level handles checking the prefix
7056 -- of the operand for this case.)
7058 if Nkind (Operand) = N_Selected_Component
7059 and then Object_Access_Level (Operand)
7060 > Type_Access_Level (Target_Type)
7061 then
7062 -- In an instance, this is a run-time check, but one we
7063 -- know will fail, so generate an appropriate warning.
7064 -- The raise will be generated by Expand_N_Type_Conversion.
7066 if In_Instance_Body then
7067 Error_Msg_N
7070 Error_Msg_N
7073 else
7074 Error_Msg_N
7077 return False;
7078 end if;
7079 end if;
7081 -- The case of a reference to an access discriminant
7082 -- from within a type declaration (which will appear
7083 -- as a discriminal) is always illegal because the
7084 -- level of the discriminant is considered to be
7085 -- deeper than any (namable) access type.
7087 if Is_Entity_Name (Operand)
7088 and then (Ekind (Entity (Operand)) = E_In_Parameter
7089 or else Ekind (Entity (Operand)) = E_Constant)
7090 and then Present (Discriminal_Link (Entity (Operand)))
7091 then
7092 Error_Msg_N
7094 Operand);
7095 return False;
7096 end if;
7097 end if;
7098 end if;
7100 declare
7101 Target : constant Entity_Id := Designated_Type (Target_Type);
7102 Opnd : constant Entity_Id := Designated_Type (Opnd_Type);
7104 begin
7105 if Is_Tagged_Type (Target) then
7106 return Valid_Tagged_Conversion (Target, Opnd);
7108 else
7109 if Base_Type (Target) /= Base_Type (Opnd) then
7110 Error_Msg_NE
7112 N, Base_Type (Opnd));
7113 return False;
7115 -- Ada 2005 AI-384: legality rule is symmetric in both
7116 -- designated types. The conversion is legal (with possible
7117 -- constraint check) if either designated type is
7118 -- unconstrained.
7120 elsif Subtypes_Statically_Match (Target, Opnd)
7121 or else
7122 (Has_Discriminants (Target)
7123 and then
7124 (not Is_Constrained (Opnd)
7125 or else not Is_Constrained (Target)))
7126 then
7127 return True;
7129 else
7130 Error_Msg_NE
7132 N, Opnd);
7133 return False;
7134 end if;
7135 end if;
7136 end;
7138 elsif (Ekind (Target_Type) = E_Access_Subprogram_Type
7139 or else
7140 Ekind (Target_Type) = E_Anonymous_Access_Subprogram_Type)
7141 and then Conversion_Check
7142 (Ekind (Base_Type (Opnd_Type)) = E_Access_Subprogram_Type,
7144 then
7145 -- Check that the designated types are subtype conformant
7147 if not Subtype_Conformant (Designated_Type (Opnd_Type),
7148 Designated_Type (Target_Type))
7149 then
7150 Error_Msg_N
7152 Operand);
7153 end if;
7155 -- Check the static accessibility rule of 4.6(20)
7157 if Type_Access_Level (Opnd_Type) >
7158 Type_Access_Level (Target_Type)
7159 then
7160 Error_Msg_N
7162 Operand);
7164 -- Check that if the operand type is declared in a generic body,
7165 -- then the target type must be declared within that same body
7166 -- (enforces last sentence of 4.6(20)).
7168 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
7169 declare
7170 O_Gen : constant Node_Id :=
7171 Enclosing_Generic_Body (Opnd_Type);
7173 T_Gen : Node_Id :=
7174 Enclosing_Generic_Body (Target_Type);
7176 begin
7177 while Present (T_Gen) and then T_Gen /= O_Gen loop
7178 T_Gen := Enclosing_Generic_Body (T_Gen);
7179 end loop;
7181 if T_Gen /= O_Gen then
7182 Error_Msg_N
7185 end if;
7186 end;
7187 end if;
7189 return True;
7191 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
7192 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
7193 then
7194 -- It is valid to convert from one RAS type to another provided
7195 -- that their specification statically match.
7197 Check_Subtype_Conformant
7198 (New_Id =>
7199 Designated_Type (Corresponding_Remote_Type (Target_Type)),
7200 Old_Id =>
7201 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
7202 Err_Loc =>
7203 N);
7204 return True;
7206 elsif Is_Tagged_Type (Target_Type) then
7207 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
7209 -- Types derived from the same root type are convertible.
7211 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
7212 return True;
7214 -- In an instance, there may be inconsistent views of the same
7215 -- type, or types derived from the same type.
7217 elsif In_Instance
7218 and then Underlying_Type (Target_Type) = Underlying_Type (Opnd_Type)
7219 then
7220 return True;
7222 -- Special check for common access type error case
7224 elsif Ekind (Target_Type) = E_Access_Type
7225 and then Is_Access_Type (Opnd_Type)
7226 then
7230 return False;
7232 else
7234 N, Opnd_Type);
7236 return False;
7237 end if;
7238 end Valid_Conversion;
7240 end Sem_Res;