| blob | 525bf67c2c35ed7194fe254b94e0bf0df7c2b193 |
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ C H 4 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2005, 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 ------------------------------------------------------------------------------
69 -----------------------
70 -- Local Subprograms --
71 -----------------------
75 -- Performs validity checks for a binary operator
77 procedure Build_Boolean_Array_Proc_Call
81 -- If an boolean array assignment can be done in place, build call to
82 -- corresponding library procedure.
85 -- Subsidiary to Expand_N_Allocator, for the case when the expression
86 -- is a qualified expression or an aggregate.
89 -- This routine handles expansion of the comparison operators (N_Op_Lt,
90 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
91 -- code for these operators is similar, differing only in the details of
92 -- the actual comparison call that is made. Special processing (call a
93 -- run-time routine)
95 function Expand_Array_Equality
101 -- Expand an array equality into a call to a function implementing this
102 -- equality, and a call to it. Loc is the location for the generated
103 -- nodes. Lhs and Rhs are the array expressions to be compared.
104 -- Bodies is a list on which to attach bodies of local functions that
105 -- are created in the process. It is the responsibility of the
106 -- caller to insert those bodies at the right place. Nod provides
107 -- the Sloc value for the generated code. Normally the types used
108 -- for the generated equality routine are taken from Lhs and Rhs.
109 -- However, in some situations of generated code, the Etype fields
110 -- of Lhs and Rhs are not set yet. In such cases, Typ supplies the
111 -- type to be used for the formal parameters.
114 -- Common expansion processing for Boolean operators (And, Or, Xor)
115 -- for the case of array type arguments.
117 function Expand_Composite_Equality
123 -- Local recursive function used to expand equality for nested
124 -- composite types. Used by Expand_Record/Array_Equality, Bodies
125 -- is a list on which to attach bodies of local functions that are
126 -- created in the process. This is the responsability of the caller
127 -- to insert those bodies at the right place. Nod provides the Sloc
128 -- value for generated code. Lhs and Rhs are the left and right sides
129 -- for the comparison, and Typ is the type of the arrays to compare.
132 -- This routine handles expansion of concatenation operations, where
133 -- N is the N_Op_Concat node being expanded and Operands is the list
134 -- of operands (at least two are present). The caller has dealt with
135 -- converting any singleton operands into singleton aggregates.
138 -- Routine to expand concatenation of 2-5 operands (in the list Operands)
139 -- and replace node Cnode with the result of the contatenation. If there
140 -- are two operands, they can be string or character. If there are more
141 -- than two operands, then are always of type string (i.e. the caller has
142 -- already converted character operands to strings in this case).
145 -- N is either an N_Op_Divide or N_Op_Multiply node whose result is
146 -- universal fixed. We do not have such a type at runtime, so the
147 -- purpose of this routine is to find the real type by looking up
148 -- the tree. We also determine if the operation must be rounded.
150 function Get_Allocator_Final_List
154 -- If the designated type is controlled, build final_list expression
155 -- for created object. If context is an access parameter, create a
156 -- local access type to have a usable finalization list.
159 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
160 -- discriminants if it has a constrained nominal type, unless the object
161 -- is a component of an enclosing Unchecked_Union object that is subject
162 -- to a per-object constraint and the enclosing object lacks inferable
163 -- discriminants.
164 --
165 -- An expression of an Unchecked_Union type has inferable discriminants
166 -- if it is either a name of an object with inferable discriminants or a
167 -- qualified expression whose subtype mark denotes a constrained subtype.
170 -- N is an expression whose type is an access. When the type of the
171 -- associated storage pool is derived from Checked_Pool, generate a
172 -- call to the 'Dereference' primitive operation.
174 function Make_Array_Comparison_Op
177 -- Comparisons between arrays are expanded in line. This function
178 -- produces the body of the implementation of (a > b), where a and b
179 -- are one-dimensional arrays of some discrete type. The original
180 -- node is then expanded into the appropriate call to this function.
181 -- Nod provides the Sloc value for the generated code.
183 function Make_Boolean_Array_Op
186 -- Boolean operations on boolean arrays are expanded in line. This
187 -- function produce the body for the node N, which is (a and b),
188 -- (a or b), or (a xor b). It is used only the normal case and not
189 -- the packed case. The type involved, Typ, is the Boolean array type,
190 -- and the logical operations in the body are simple boolean operations.
191 -- Note that Typ is always a constrained type (the caller has ensured
192 -- this by using Convert_To_Actual_Subtype if necessary).
195 -- N is the node for a compile time comparison. If this outcome of this
196 -- comparison can be determined at compile time, then the node N can be
197 -- rewritten with True or False. If the outcome cannot be determined at
198 -- compile time, the call has no effect.
201 -- Construct the expression corresponding to the tagged membership test.
202 -- Deals with a second operand being (or not) a class-wide type.
204 function Safe_In_Place_Array_Op
208 -- In the context of an assignment, where the right-hand side is a
209 -- boolean operation on arrays, check whether operation can be performed
210 -- in place.
214 -- Performs validity checks for a unary operator
216 -------------------------------
217 -- Binary_Op_Validity_Checks --
218 -------------------------------
221 begin
228 ------------------------------------
229 -- Build_Boolean_Array_Proc_Call --
230 ------------------------------------
232 procedure Build_Boolean_Array_Proc_Call
236 is
249 begin
253 -- Use negated version of the binary operators
265 Call_Node :=
270 Target,
283 else
286 Call_Node :=
290 Target,
301 else
302 -- We use the following equivalences:
304 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
305 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
306 -- (not X) xor (not Y) = X xor Y
307 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
316 else
320 else
331 else
336 Call_Node :=
340 Target,
355 exception
360 ---------------------------------
361 -- Expand_Allocator_Expression --
362 ---------------------------------
379 begin
382 -- Actions inserted before:
383 -- Temp : constant ptr_T := new T'(Expression);
384 -- <no CW> Temp._tag := T'tag;
385 -- <CTRL> Adjust (Finalizable (Temp.all));
386 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
388 -- We analyze by hand the new internal allocator to avoid
389 -- any recursion and inappropriate call to Initialize
395 Temp :=
398 -- For a class wide allocation generate the following code:
400 -- type Equiv_Record is record ... end record;
401 -- implicit subtype CW is <Class_Wide_Subytpe>;
402 -- temp : PtrT := new CW'(CW!(expr));
414 Tmp_Node :=
418 Expression =>
422 Set_Comes_From_Source
430 then
431 -- Create local finalization list for access parameter
437 else
448 -- Suppress the tag assignment when Java_VM because JVM tags
449 -- are represented implicitly in objects.
453 and then not Java_VM
454 then
455 Tag_Assign :=
457 Name =>
460 Selector_Name =>
463 Expression =>
465 New_Reference_To
467 Loc)));
469 -- The previous assignment has to be done in any case
476 and then not Java_VM
477 then
478 declare
485 begin
486 Tag_Assign :=
488 Name =>
491 Selector_Name =>
494 Expression =>
496 New_Reference_To (
498 Loc)));
507 then
508 declare
513 begin
514 -- If it is an allocation on the secondary stack
515 -- (i.e. a value returned from a function), the object
516 -- is attached on the caller side as soon as the call
517 -- is completed (see Expand_Ctrl_Function_Call)
520 declare
524 begin
535 -- Normal case, not a secondary stack allocation
537 else
540 then
541 -- Create local finalization list for access parameter
543 Flist :=
545 else
554 Make_Adjust_Call (
555 Ref =>
557 -- An unchecked conversion is needed in the
558 -- classwide case because the designated type
559 -- can be an ancestor of the subtype mark of
560 -- the allocator.
577 Temp :=
579 Tmp_Node :=
586 Set_Comes_From_Source
598 then
599 -- Apply constraint to designated subtype indication
607 -- Propagate constraint_error to enclosing allocator
611 else
612 -- First check against the type of the qualified expression
613 --
614 -- NOTE: The commented call should be correct, but for
615 -- some reason causes the compiler to bomb (sigsegv) on
616 -- ACVC test c34007g, so for now we just perform the old
617 -- (incorrect) test against the designated subtype with
618 -- no sliding in the else part of the if statement below.
619 -- ???
620 --
621 -- Apply_Constraint_Check (Exp, T, No_Sliding => True);
623 -- A check is also needed in cases where the designated
624 -- subtype is constrained and differs from the subtype
625 -- given in the qualified expression. Note that the check
626 -- on the qualified expression does not allow sliding,
627 -- but this check does (a relaxation from Ada 83).
630 and then not Subtypes_Statically_Match
632 then
633 Apply_Constraint_Check
636 -- The nonsliding check should really be performed
637 -- (unconditionally) against the subtype of the
638 -- qualified expression, but that causes a problem
639 -- with c34007g (see above), so for now we retain this.
641 else
642 Apply_Constraint_Check
647 exception
652 -----------------------------
653 -- Expand_Array_Comparison --
654 -----------------------------
656 -- Expansion is only required in the case of array types. For the
657 -- unpacked case, an appropriate runtime routine is called. For
658 -- packed cases, and also in some other cases where a runtime
659 -- routine cannot be called, the form of the expansion is:
661 -- [body for greater_nn; boolean_expression]
663 -- The body is built by Make_Array_Comparison_Op, and the form of the
664 -- Boolean expression depends on the operator involved.
680 -- True for byte addressable target
683 -- Returns True if the length of the given operand is known to be
684 -- less than 4. Returns False if this length is known to be four
685 -- or greater or is not known at compile time.
687 ------------------------
688 -- Length_Less_Than_4 --
689 ------------------------
694 begin
698 else
699 declare
706 begin
709 else
715 else
724 -- Start of processing for Expand_Array_Comparison
726 begin
727 -- Deal first with unpacked case, where we can call a runtime routine
728 -- except that we avoid this for targets for which are not addressable
729 -- by bytes, and for the JVM, since the JVM does not support direct
730 -- addressing of array components.
733 and then Byte_Addressable
734 and then not Java_VM
735 then
736 -- The call we generate is:
738 -- Compare_Array_xn[_Unaligned]
739 -- (left'address, right'address, left'length, right'length) <op> 0
741 -- x = U for unsigned, S for signed
742 -- n = 8,16,32,64 for component size
743 -- Add _Unaligned if length < 4 and component size is 8.
744 -- <op> is the standard comparison operator
748 or else
750 then
753 else
757 else
760 else
768 else
775 else
782 else
820 -- Cases where we cannot make runtime call
822 -- For (a <= b) we convert to not (a > b)
827 Right_Opnd =>
834 -- For < the Boolean expression is
835 -- greater__nn (op2, op1)
840 -- Switch operands
845 -- For (a >= b) we convert to not (a < b)
850 Right_Opnd =>
857 -- For > the Boolean expression is
858 -- greater__nn (op1, op2)
860 else
866 Expr :=
875 exception
880 ---------------------------
881 -- Expand_Array_Equality --
882 ---------------------------
884 -- Expand an equality function for multi-dimensional arrays. Here is
885 -- an example of such a function for Nb_Dimension = 2
887 -- function Enn (A : atyp; B : btyp) return boolean is
888 -- begin
889 -- if (A'length (1) = 0 or else A'length (2) = 0)
890 -- and then
891 -- (B'length (1) = 0 or else B'length (2) = 0)
892 -- then
893 -- return True; -- RM 4.5.2(22)
894 -- end if;
896 -- if A'length (1) /= B'length (1)
897 -- or else
898 -- A'length (2) /= B'length (2)
899 -- then
900 -- return False; -- RM 4.5.2(23)
901 -- end if;
903 -- declare
904 -- A1 : Index_T1 := A'first (1);
905 -- B1 : Index_T1 := B'first (1);
906 -- begin
907 -- loop
908 -- declare
909 -- A2 : Index_T2 := A'first (2);
910 -- B2 : Index_T2 := B'first (2);
911 -- begin
912 -- loop
913 -- if A (A1, A2) /= B (B1, B2) then
914 -- return False;
915 -- end if;
917 -- exit when A2 = A'last (2);
918 -- A2 := Index_T2'succ (A2);
919 -- B2 := Index_T2'succ (B2);
920 -- end loop;
921 -- end;
923 -- exit when A1 = A'last (1);
924 -- A1 := Index_T1'succ (A1);
925 -- B1 := Index_T1'succ (B1);
926 -- end loop;
927 -- end;
929 -- return true;
930 -- end Enn;
932 -- Note on the formal types used (atyp and btyp). If either of the
933 -- arrays is of a private type, we use the underlying type, and
934 -- do an unchecked conversion of the actual. If either of the arrays
935 -- has a bound depending on a discriminant, then we use the base type
936 -- since otherwise we have an escaped discriminant in the function.
938 -- If both arrays are constrained and have the same bounds, we can
939 -- generate a loop with an explicit iteration scheme using a 'Range
940 -- attribute over the first array.
942 function Expand_Array_Equality
948 is
964 -- The parameter types to be used for the formals
966 function Arr_Attr
970 -- This builds the attribute reference Arr'Nam (Expr)
973 -- Create one statement to compare corresponding components,
974 -- designated by a full set of indices.
977 -- Given one of the arguments, computes the appropriate type to
978 -- be used for that argument in the corresponding function formal
980 function Handle_One_Dimension
983 -- This procedure returns the following code
984 --
985 -- declare
986 -- Bn : Index_T := B'First (N);
987 -- begin
988 -- loop
989 -- xxx
990 -- exit when An = A'Last (N);
991 -- An := Index_T'Succ (An)
992 -- Bn := Index_T'Succ (Bn)
993 -- end loop;
994 -- end;
995 --
996 -- If both indices are constrained and identical, the procedure
997 -- returns a simpler loop:
998 --
999 -- for An in A'Range (N) loop
1000 -- xxx
1001 -- end loop
1002 --
1003 -- N is the dimension for which we are generating a loop. Index is the
1004 -- N'th index node, whose Etype is Index_Type_n in the above code.
1005 -- The xxx statement is either the loop or declare for the next
1006 -- dimension or if this is the last dimension the comparison
1007 -- of corresponding components of the arrays.
1008 --
1009 -- The actual way the code works is to return the comparison
1010 -- of corresponding components for the N+1 call. That's neater!
1013 -- This function constructs the test for both arrays being empty
1014 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1015 -- and then
1016 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1019 -- This function constructs the test for arrays having different
1020 -- lengths in at least one index position, in which case resull
1022 -- A'length (1) /= B'length (1)
1023 -- or else
1024 -- A'length (2) /= B'length (2)
1025 -- or else
1026 -- ...
1028 --------------
1029 -- Arr_Attr --
1030 --------------
1032 function Arr_Attr
1036 is
1037 begin
1038 return
1045 ------------------------
1046 -- Component_Equality --
1047 ------------------------
1053 begin
1054 -- if a(i1...) /= b(j1...) then return false; end if;
1056 L :=
1061 R :=
1066 Test := Expand_Composite_Equality
1069 -- If some (sub)component is an unchecked_union, the whole operation
1070 -- will raise program error.
1074 -- This node is going to be inserted at a location where a
1075 -- statement is expected: clear its Etype so analysis will
1076 -- set it to the expected Standard_Void_Type.
1081 else
1082 return
1091 ------------------
1092 -- Get_Arg_Type --
1093 ------------------
1099 begin
1105 else
1111 or else
1113 then
1125 --------------------------
1126 -- Handle_One_Dimension --
1127 ---------------------------
1129 function Handle_One_Dimension
1132 is
1134 Ltyp /= Rtyp
1136 -- If the index types are identical, and we are working with
1137 -- constrained types, then we can use the same index for both of
1138 -- the arrays.
1148 begin
1153 -- Case where we generate a loop
1158 Bn :=
1161 else
1173 -- Generate guard for loop, followed by increments of indices
1177 Condition =>
1185 Expression =>
1194 Expression =>
1201 -- If separate indexes, we need a declare block for An and Bn, and a
1202 -- loop without an iteration scheme.
1205 Loop_Stm :=
1208 return
1221 Handled_Statement_Sequence =>
1225 -- If no separate indexes, return loop statement with explicit
1226 -- iteration scheme on its own
1228 else
1229 Loop_Stm :=
1232 Iteration_Scheme =>
1234 Loop_Parameter_Specification =>
1237 Discrete_Subtype_Definition =>
1243 -----------------------
1244 -- Test_Empty_Arrays --
1245 -----------------------
1254 begin
1258 Atest :=
1263 Btest :=
1272 else
1273 Alist :=
1278 Blist :=
1285 return
1291 -----------------------------
1292 -- Test_Lengths_Correspond --
1293 -----------------------------
1299 begin
1302 Rtest :=
1309 else
1310 Result :=
1320 -- Start of processing for Expand_Array_Equality
1322 begin
1326 -- For now, if the argument types are not the same, go to the
1327 -- base type, since the code assumes that the formals have the
1328 -- same type. This is fixable in future ???
1336 -- Build list of formals for function
1349 -- Build statement sequence for function
1351 Func_Body :=
1353 Specification =>
1361 Handled_Statement_Sequence =>
1369 Expression =>
1376 Expression =>
1387 -- If the array type is distinct from the type of the arguments,
1388 -- it is the full view of a private type. Apply an unchecked
1389 -- conversion to insure that analysis of the call succeeds.
1391 declare
1394 begin
1400 then
1406 then
1415 return
1421 -----------------------------
1422 -- Expand_Boolean_Operator --
1423 -----------------------------
1425 -- Note that we first get the actual subtypes of the operands,
1426 -- since we always want to deal with types that have bounds.
1431 begin
1432 -- Special case of bit packed array where both operands are known
1433 -- to be properly aligned. In this case we use an efficient run time
1434 -- routine to carry out the operation (see System.Bit_Ops).
1439 then
1444 -- For the normal non-packed case, the general expansion is to build
1445 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
1446 -- and then inserting it into the tree. The original operator node is
1447 -- then rewritten as a call to this function. We also use this in the
1448 -- packed case if either operand is a possibly unaligned object.
1450 declare
1457 begin
1466 then
1471 and then
1473 then
1475 else
1481 -- Now rewrite the expression with a call
1486 Parameter_Associations =>
1487 New_List (
1488 L,
1489 Make_Type_Conversion
1497 -------------------------------
1498 -- Expand_Composite_Equality --
1499 -------------------------------
1501 -- This function is only called for comparing internal fields of composite
1502 -- types when these fields are themselves composites. This is a special
1503 -- case because it is not possible to respect normal Ada visibility rules.
1505 function Expand_Composite_Equality
1511 is
1517 begin
1520 else
1524 -- Defense against malformed private types with no completion
1525 -- the error will be diagnosed later by check_completion
1535 -- If the operand is an elementary type other than a floating-point
1536 -- type, then we can simply use the built-in block bitwise equality,
1537 -- since the predefined equality operators always apply and bitwise
1538 -- equality is fine for all these cases.
1542 then
1545 -- For composite component types, and floating-point types, use
1546 -- the expansion. This deals with tagged component types (where
1547 -- we use the applicable equality routine) and floating-point,
1548 -- (where we need to worry about negative zeroes), and also the
1549 -- case of any composite type recursively containing such fields.
1551 else
1557 -- Call the primitive operation "=" of this type
1563 -- If this is derived from an untagged private type completed
1564 -- with a tagged type, it does not have a full view, so we
1565 -- use the primitive operations of the private type.
1566 -- This check should no longer be necessary when these
1567 -- types receive their full views ???
1574 then
1576 else
1580 loop
1592 return
1595 Parameter_Associations =>
1596 New_List
1606 -- Inherited equality from parent type. Convert the actuals
1607 -- to match signature of operation.
1609 declare
1612 begin
1613 return
1616 Parameter_Associations =>
1621 else
1622 -- Comparison between Unchecked_Union components
1625 declare
1631 begin
1632 -- Lhs subtype
1638 -- Rhs subtype
1644 -- Lhs of the composite equality
1648 -- Since the enclosing record can never be an
1649 -- Unchecked_Union (this code is executed for records
1650 -- that do not have variants), we may reference its
1651 -- discriminant(s).
1656 then
1657 Lhs_Discr_Val :=
1660 Selector_Name =>
1661 New_Copy (
1662 Get_Discriminant_Value (
1664 Lhs_Type,
1667 else
1669 Get_Discriminant_Value (
1671 Lhs_Type,
1675 else
1676 -- It is not possible to infer the discriminant since
1677 -- the subtype is not constrained.
1679 return
1684 -- Rhs of the composite equality
1690 then
1691 Rhs_Discr_Val :=
1694 Selector_Name =>
1695 New_Copy (
1696 Get_Discriminant_Value (
1698 Rhs_Type,
1701 else
1703 Get_Discriminant_Value (
1705 Rhs_Type,
1709 else
1710 return
1715 -- Call the TSS equality function with the inferred
1716 -- discriminant values.
1718 return
1722 Lhs,
1723 Rhs,
1724 Lhs_Discr_Val,
1725 Rhs_Discr_Val));
1729 -- Shouldn't this be an else, we can't fall through
1730 -- the above IF, right???
1732 return
1738 else
1742 else
1743 -- It can be a simple record or the full view of a scalar private
1749 ------------------------------
1750 -- Expand_Concatenate_Other --
1751 ------------------------------
1753 -- Let n be the number of array operands to be concatenated, Base_Typ
1754 -- their base type, Ind_Typ their index type, and Arr_Typ the original
1755 -- array type to which the concatenantion operator applies, then the
1756 -- following subprogram is constructed:
1758 -- [function Cnn (S1 : Base_Typ; ...; Sn : Base_Typ) return Base_Typ is
1759 -- L : Ind_Typ;
1760 -- begin
1761 -- if S1'Length /= 0 then
1762 -- L := XXX; --> XXX = S1'First if Arr_Typ is unconstrained
1763 -- XXX = Arr_Typ'First otherwise
1764 -- elsif S2'Length /= 0 then
1765 -- L := YYY; --> YYY = S2'First if Arr_Typ is unconstrained
1766 -- YYY = Arr_Typ'First otherwise
1767 -- ...
1768 -- elsif Sn-1'Length /= 0 then
1769 -- L := ZZZ; --> ZZZ = Sn-1'First if Arr_Typ is unconstrained
1770 -- ZZZ = Arr_Typ'First otherwise
1771 -- else
1772 -- return Sn;
1773 -- end if;
1775 -- declare
1776 -- P : Ind_Typ;
1777 -- H : Ind_Typ :=
1778 -- Ind_Typ'Val ((((S1'Length - 1) + S2'Length) + ... + Sn'Length)
1779 -- + Ind_Typ'Pos (L));
1780 -- R : Base_Typ (L .. H);
1781 -- begin
1782 -- if S1'Length /= 0 then
1783 -- P := S1'First;
1784 -- loop
1785 -- R (L) := S1 (P);
1786 -- L := Ind_Typ'Succ (L);
1787 -- exit when P = S1'Last;
1788 -- P := Ind_Typ'Succ (P);
1789 -- end loop;
1790 -- end if;
1791 --
1792 -- if S2'Length /= 0 then
1793 -- L := Ind_Typ'Succ (L);
1794 -- loop
1795 -- R (L) := S2 (P);
1796 -- L := Ind_Typ'Succ (L);
1797 -- exit when P = S2'Last;
1798 -- P := Ind_Typ'Succ (P);
1799 -- end loop;
1800 -- end if;
1802 -- . . .
1804 -- if Sn'Length /= 0 then
1805 -- P := Sn'First;
1806 -- loop
1807 -- R (L) := Sn (P);
1808 -- L := Ind_Typ'Succ (L);
1809 -- exit when P = Sn'Last;
1810 -- P := Ind_Typ'Succ (P);
1811 -- end loop;
1812 -- end if;
1814 -- return R;
1815 -- end;
1816 -- end Cnn;]
1854 -- Builds the sequence of statement:
1855 -- P := Si'First;
1856 -- loop
1857 -- R (L) := Si (P);
1858 -- L := Ind_Typ'Succ (L);
1859 -- exit when P = Si'Last;
1860 -- P := Ind_Typ'Succ (P);
1861 -- end loop;
1862 --
1863 -- where i is the input parameter I given.
1864 -- If the flag Last is true, the exit statement is emitted before
1865 -- incrementing the lower bound, to prevent the creation out of
1866 -- bound values.
1869 -- Builds the statement:
1870 -- L := Arr_Typ'First; If Arr_Typ is constrained
1871 -- L := Si'First; otherwise (where I is the input param given)
1874 -- Builds reference to identifier H
1877 -- Builds expression Ind_Typ'Val (E);
1880 -- Builds reference to identifier L
1883 -- Builds expression Integer_Type'(Ind_Typ'Pos (L)). We qualify the
1884 -- expression to avoid universal_integer computations whenever possible,
1885 -- in the expression for the upper bound H.
1888 -- Builds expression Ind_Typ'Succ (L)
1891 -- Builds integer literal one
1894 -- Builds reference to identifier P
1897 -- Builds expression Ind_Typ'Succ (P)
1900 -- Builds reference to identifier R
1903 -- Builds reference to identifier Si, where I is the value given
1906 -- Builds expression Si'First, where I is the value given
1909 -- Builds expression Si'Last, where I is the value given
1912 -- Builds expression Si'Length, where I is the value given
1915 -- Builds expression Si'Length /= 0, where I is the value given
1917 -------------------
1918 -- Copy_Into_R_S --
1919 -------------------
1930 begin
1931 -- First construct the initializations
1938 -- Then build the loop
1960 Loop_Stmt :=
1963 else
1964 Loop_Stmt :=
1974 -------
1975 -- H --
1976 -------
1979 begin
1983 -------------
1984 -- Ind_Val --
1985 -------------
1988 begin
1989 return
1996 ------------
1997 -- Init_L --
1998 ------------
2003 begin
2009 else
2016 -------
2017 -- L --
2018 -------
2021 begin
2025 -----------
2026 -- L_Pos --
2027 -----------
2032 begin
2033 -- If the index type is an enumeration type, the computation
2034 -- can be done in standard integer. Otherwise, choose a large
2035 -- enough integer type.
2041 then
2043 else
2047 return
2050 Expression =>
2057 ------------
2058 -- L_Succ --
2059 ------------
2062 begin
2063 return
2070 ---------
2071 -- One --
2072 ---------
2075 begin
2079 -------
2080 -- P --
2081 -------
2084 begin
2088 ------------
2089 -- P_Succ --
2090 ------------
2093 begin
2094 return
2101 -------
2102 -- R --
2103 -------
2106 begin
2110 -------
2111 -- S --
2112 -------
2115 begin
2119 -------------
2120 -- S_First --
2121 -------------
2124 begin
2130 ------------
2131 -- S_Last --
2132 ------------
2135 begin
2141 --------------
2142 -- S_Length --
2143 --------------
2146 begin
2152 -------------------
2153 -- S_Length_Test --
2154 -------------------
2157 begin
2158 return
2164 -- Start of processing for Expand_Concatenate_Other
2166 begin
2167 -- Construct the parameter specs and the overall function spec
2171 Append_To
2174 Defining_Identifier =>
2180 Func_Spec :=
2186 -- Construct L's object declaration
2188 L_Decl :=
2195 -- Construct the if-then-elsif statements
2204 If_Stmt :=
2212 -- Construct the declaration for H
2214 P_Decl :=
2225 H_Decl :=
2231 -- Construct the declaration for R
2234 R_Constr :=
2238 R_Decl :=
2241 Object_Definition =>
2246 -- Construct the declarations for the declare block
2250 -- Construct list of statements for the declare block
2262 -- Construct the declare block
2266 Handled_Statement_Sequence =>
2269 -- Construct the list of function statements
2273 -- Construct the function body
2275 Func_Body :=
2279 Handled_Statement_Sequence =>
2282 -- Insert the newly generated function in the code. This is analyzed
2283 -- with all checks off, since we have completed all the checks.
2285 -- Note that this does *not* fix the array concatenation bug when the
2286 -- low bound is Integer'first sibce that bug comes from the pointer
2287 -- dereferencing an unconstrained array. An there we need a constraint
2288 -- check to make sure the length of the concatenated array is ok. ???
2292 -- Construct list of arguments for the function call
2301 -- Insert the function call
2303 Rewrite
2311 -------------------------------
2312 -- Expand_Concatenate_String --
2313 -------------------------------
2323 -- RE_Id value for function to be called
2325 begin
2326 -- In all cases, we build a call to a routine giving the list of
2327 -- arguments as the parameter list to the routine.
2335 else
2344 else
2349 -- If we have anything other than Standard_Character or
2350 -- Standard_String, then we must have had a serious error
2351 -- earlier, so we just abandon the attempt at expansion.
2353 else
2372 -- Now generate the appropriate call
2381 exception
2386 ------------------------
2387 -- Expand_N_Allocator --
2388 ------------------------
2398 begin
2399 -- RM E.2.3(22). We enforce that the expected type of an allocator
2400 -- shall not be a remote access-to-class-wide-limited-private type
2402 -- Why is this being done at expansion time, seems clearly wrong ???
2406 -- Set the Storage Pool
2419 else
2425 -- Under certain circumstances we can replace an allocator by an
2426 -- access to statically allocated storage. The conditions, as noted
2427 -- in AARM 3.10 (10c) are as follows:
2429 -- Size and initial value is known at compile time
2430 -- Access type is access-to-constant
2432 -- The allocator is not part of a constraint on a record component,
2433 -- because in that case the inserted actions are delayed until the
2434 -- record declaration is fully analyzed, which is too late for the
2435 -- analysis of the rewritten allocator.
2443 then
2444 -- Here we can do the optimization. For the allocator
2446 -- new x'(y)
2448 -- We insert an object declaration
2450 -- Tnn : aliased x := y;
2452 -- and replace the allocator by Tnn'Unrestricted_Access.
2453 -- Tnn is marked as requiring static allocation.
2455 Temp :=
2460 -- If context is constrained, use constrained subtype directly,
2461 -- so that the constant is not labelled as having a nomimally
2462 -- unconstrained subtype.
2483 -- We set the variable as statically allocated, since we don't
2484 -- want it going on the stack of the current procedure!
2490 -- Handle case of qualified expression (other than optimization above)
2495 -- If the allocator is for a type which requires initialization, and
2496 -- there is no initial value (i.e. operand is a subtype indication
2497 -- rather than a qualifed expression), then we must generate a call
2498 -- to the initialization routine. This is done using an expression
2499 -- actions node:
2500 --
2501 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
2502 --
2503 -- Here ptr_T is the pointer type for the allocator, and T is the
2504 -- subtype of the allocator. A special case arises if the designated
2505 -- type of the access type is a task or contains tasks. In this case
2506 -- the call to Init (Temp.all ...) is replaced by code that ensures
2507 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
2508 -- for details). In addition, if the type T is a task T, then the
2509 -- first argument to Init must be converted to the task record type.
2511 else
2512 declare
2525 begin
2529 -- Case of no initialization procedure present
2533 -- Case of simple initialization required
2546 -- No initialization required
2548 else
2552 -- Case of initialization procedure present, must be called
2554 else
2557 Temp :=
2560 -- Construct argument list for the initialization routine call
2561 -- The CPP constructor needs the address directly
2567 else
2568 Arg1 :=
2574 -- The initialization procedure expects a specific type.
2575 -- if the context is access to class wide, indicate that
2576 -- the object being allocated has the right specific type.
2583 -- If designated type is a concurrent type or if it is a
2584 -- private type whose definition is a concurrent type,
2585 -- the first argument in the Init routine has to be
2586 -- unchecked conversion to the corresponding record type.
2587 -- If the designated type is a derived type, we also
2588 -- convert the argument to its root type.
2591 Arg1 :=
2597 then
2598 Arg1 :=
2599 Unchecked_Convert_To
2604 declare
2607 begin
2615 -- For the task case, pass the Master_Id of the access type
2616 -- as the value of the _Master parameter, and _Chain as the
2617 -- value of the _Chain parameter (_Chain will be defined as
2618 -- part of the generated code for the allocator).
2623 -- The designated type was an incomplete type, and
2624 -- the access type did not get expanded. Salvage
2625 -- it now.
2627 Expand_N_Full_Type_Declaration
2631 -- If the context of the allocator is a declaration or
2632 -- an assignment, we can generate a meaningful image for
2633 -- it, even though subsequent assignments might remove
2634 -- the connection between task and entity. We build this
2635 -- image when the left-hand side is a simple variable,
2636 -- a simple indexed assignment or a simple selected
2637 -- component.
2640 declare
2643 begin
2645 Decls :=
2646 Build_Task_Image_Decls (
2647 Loc,
2648 New_Occurrence_Of
2654 then
2655 Decls :=
2656 Build_Task_Image_Decls
2658 else
2664 Decls :=
2665 Build_Task_Image_Decls (
2668 else
2673 New_Reference_To
2681 -- Has_Task is false, Decls not used
2683 else
2687 -- Add discriminants if discriminated type
2700 then
2701 Discr :=
2710 -- We set the allocator as analyzed so that when we analyze the
2711 -- expression actions node, we do not get an unwanted recursive
2712 -- expansion of the allocator expression.
2717 -- Here is the transformation:
2718 -- input: new T
2719 -- output: Temp : constant ptr_T := new T;
2720 -- Init (Temp.all, ...);
2721 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
2722 -- <CTRL> Initialize (Finalizable (Temp.all));
2724 -- Here ptr_T is the pointer type for the allocator, and T
2725 -- is the subtype of the allocator.
2727 Temp_Decl :=
2742 -- If the designated type is task type or contains tasks,
2743 -- Create block to activate created tasks, and insert
2744 -- declaration for Task_Image variable ahead of call.
2747 declare
2751 begin
2759 else
2770 else
2774 Make_Init_Call (
2779 Attach_Level)));
2787 else
2796 exception
2801 -----------------------
2802 -- Expand_N_And_Then --
2803 -----------------------
2805 -- Expand into conditional expression if Actions present, and also
2806 -- deal with optimizing case of arguments being True or False.
2815 begin
2816 -- Deal with non-standard booleans
2824 -- Check for cases of left argument is True or False
2828 -- If left argument is True, change (True and then Right) to Right.
2829 -- Any actions associated with Right will be executed unconditionally
2830 -- and can thus be inserted into the tree unconditionally.
2841 -- If left argument is False, change (False and then Right) to
2842 -- False. In this case we can forget the actions associated with
2843 -- Right, since they will never be executed.
2854 -- If Actions are present, we expand
2856 -- left and then right
2858 -- into
2860 -- if left then right else false end
2862 -- with the actions becoming the Then_Actions of the conditional
2863 -- expression. This conditional expression is then further expanded
2864 -- (and will eventually disappear)
2871 Left,
2872 Right,
2881 -- No actions present, check for cases of right argument True/False
2885 -- Change (Left and then True) to Left. Note that we know there
2886 -- are no actions associated with the True operand, since we
2887 -- just checked for this case above.
2892 -- Change (Left and then False) to False, making sure to preserve
2893 -- any side effects associated with the Left operand.
2897 Rewrite
2905 -------------------------------------
2906 -- Expand_N_Conditional_Expression --
2907 -------------------------------------
2909 -- Expand into expression actions if then/else actions present
2920 begin
2921 -- If either then or else actions are present, then given:
2923 -- if cond then then-expr else else-expr end
2925 -- we insert the following sequence of actions (using Insert_Actions):
2927 -- Cnn : typ;
2928 -- if cond then
2929 -- <<then actions>>
2930 -- Cnn := then-expr;
2931 -- else
2932 -- <<else actions>>
2933 -- Cnn := else-expr
2934 -- end if;
2936 -- and replace the conditional expression by a reference to Cnn
2941 New_If :=
2959 Insert_List_Before
2964 Insert_List_Before
2980 -----------------------------------
2981 -- Expand_N_Explicit_Dereference --
2982 -----------------------------------
2985 begin
2986 -- The only processing required is an insertion of an explicit
2987 -- dereference call for the checked storage pool case.
2992 -----------------
2993 -- Expand_N_In --
2994 -----------------
3003 begin
3004 -- If we have an explicit range, do a bit of optimization based
3005 -- on range analysis (we may be able to kill one or both checks).
3008 declare
3014 begin
3015 -- If either check is known to fail, replace result
3016 -- by False, since the other check does not matter.
3017 -- Preserve the static flag for legality checks, because
3018 -- we are constant-folding beyond RM 4.9.
3027 -- If both checks are known to succeed, replace result
3028 -- by True, since we know we are in range.
3037 -- If lower bound check succeeds and upper bound check is
3038 -- not known to succeed or fail, then replace the range check
3039 -- with a comparison against the upper bound.
3049 -- If upper bound check succeeds and lower bound check is
3050 -- not known to succeed or fail, then replace the range check
3051 -- with a comparison against the lower bound.
3063 -- For all other cases of an explicit range, nothing to be done
3067 -- Here right operand is a subtype mark
3069 else
3070 declare
3076 begin
3079 -- For tagged type, do tagged membership operation
3083 -- No expansion will be performed when Java_VM, as the
3084 -- JVM back end will handle the membership tests directly
3085 -- (tags are not explicitly represented in Java objects,
3086 -- so the normal tagged membership expansion is not what
3087 -- we want).
3096 -- If type is scalar type, rewrite as x in t'first .. t'last
3097 -- This reason we do this is that the bounds may have the wrong
3098 -- type if they come from the original type definition.
3103 Low_Bound =>
3108 High_Bound =>
3115 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
3116 -- a membership test if the subtype mark denotes a constrained
3117 -- Unchecked_Union subtype and the expression lacks inferable
3118 -- discriminants.
3123 then
3128 -- Prevent Gigi from generating incorrect code by rewriting
3129 -- the test as a standard False.
3137 -- Here we have a non-scalar type
3148 -- For the constrained array case, we have to check the
3149 -- subscripts for an exact match if the lengths are
3150 -- non-zero (the lengths must match in any case).
3155 function Construct_Attribute_Reference
3159 -- Build attribute reference E'Nam(Dim)
3161 -----------------------------------
3162 -- Construct_Attribute_Reference --
3163 -----------------------------------
3165 function Construct_Attribute_Reference
3169 is
3170 begin
3171 return
3179 -- Start processing for Check_Subscripts
3181 begin
3185 Left_Opnd =>
3186 Construct_Attribute_Reference
3189 Right_Opnd =>
3190 Construct_Attribute_Reference
3195 Left_Opnd =>
3196 Construct_Attribute_Reference
3199 Right_Opnd =>
3200 Construct_Attribute_Reference
3205 Cond :=
3207 Left_Opnd =>
3218 -- These are the cases where constraint checks may be
3219 -- required, e.g. records with possible discriminants
3221 else
3222 -- Expand the test into a series of discriminant comparisons.
3223 -- The expression that is built is the negation of the one
3224 -- that is used for checking discriminant constraints.
3234 Left_Opnd =>
3241 else
3252 --------------------------------
3253 -- Expand_N_Indexed_Component --
3254 --------------------------------
3262 begin
3263 -- A special optimization, if we have an indexed component that
3264 -- is selecting from a slice, then we can eliminate the slice,
3265 -- since, for example, x (i .. j)(k) is identical to x(k). The
3266 -- only difference is the range check required by the slice. The
3267 -- range check for the slice itself has already been generated.
3268 -- The range check for the subscripting operation is ensured
3269 -- by converting the subject to the subtype of the slice.
3271 -- This optimization not only generates better code, avoiding
3272 -- slice messing especially in the packed case, but more importantly
3273 -- bypasses some problems in handling this peculiar case, for
3274 -- example, the issue of dealing specially with object renamings.
3281 Convert_To
3288 -- If the prefix is an access type, then we unconditionally rewrite
3289 -- if as an explicit deference. This simplifies processing for several
3290 -- cases, including packed array cases and certain cases in which
3291 -- checks must be generated. We used to try to do this only when it
3292 -- was necessary, but it cleans up the code to do it all the time.
3299 -- Generate index and validity checks
3307 -- All done for the non-packed case
3313 -- For packed arrays that are not bit-packed (i.e. the case of an array
3314 -- with one or more index types with a non-coniguous enumeration type),
3315 -- we can always use the normal packed element get circuit.
3322 -- For a reference to a component of a bit packed array, we have to
3323 -- convert it to a reference to the corresponding Packed_Array_Type.
3324 -- We only want to do this for simple references, and not for:
3326 -- Left side of assignment, or prefix of left side of assignment,
3327 -- or prefix of the prefix, to handle packed arrays of packed arrays,
3328 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
3330 -- Renaming objects in renaming associations
3331 -- This case is handled when a use of the renamed variable occurs
3333 -- Actual parameters for a procedure call
3334 -- This case is handled in Exp_Ch6.Expand_Actuals
3336 -- The second expression in a 'Read attribute reference
3338 -- The prefix of an address or size attribute reference
3340 -- The following circuit detects these exceptions
3342 declare
3346 begin
3347 loop
3354 and then
3356 then
3361 or else
3364 then
3369 then
3372 -- If the expression is an index of an indexed component,
3373 -- it must be expanded regardless of context.
3377 then
3383 then
3389 then
3395 then
3398 else
3403 -- Keep looking up tree for unchecked expression, or if we are
3404 -- the prefix of a possible assignment left side.
3413 ---------------------
3414 -- Expand_N_Not_In --
3415 ---------------------
3417 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
3418 -- can be done. This avoids needing to duplicate this expansion code.
3424 begin
3427 Right_Opnd =>
3434 -------------------
3435 -- Expand_N_Null --
3436 -------------------
3438 -- The only replacement required is for the case of a null of type
3439 -- that is an access to protected subprogram. We represent such
3440 -- access values as a record, and so we must replace the occurrence
3441 -- of null by the equivalent record (with a null address and a null
3442 -- pointer in it), so that the backend creates the proper value.
3449 begin
3451 Agg :=
3460 -- For subsequent semantic analysis, the node must retain its
3461 -- type. Gigi in any case replaces this type by the corresponding
3462 -- record type before processing the node.
3467 exception
3472 ---------------------
3473 -- Expand_N_Op_Abs --
3474 ---------------------
3480 begin
3483 -- Deal with software overflow checking
3485 if not Backend_Overflow_Checks_On_Target
3488 then
3489 -- The only case to worry about is when the argument is
3490 -- equal to the largest negative number, so what we do is
3491 -- to insert the check:
3493 -- [constraint_error when Expr = typ'Base'First]
3495 -- with the usual Duplicate_Subexpr use coding for expr
3499 Condition =>
3502 Right_Opnd =>
3504 Prefix =>
3510 -- Vax floating-point types case
3517 ---------------------
3518 -- Expand_N_Op_Add --
3519 ---------------------
3524 begin
3527 -- N + 0 = 0 + N = N for integer types
3532 then
3538 then
3544 -- Arithmetic overflow checks for signed integer/fixed point types
3548 then
3552 -- Vax floating-point types case
3559 ---------------------
3560 -- Expand_N_Op_And --
3561 ---------------------
3566 begin
3580 ------------------------
3581 -- Expand_N_Op_Concat --
3582 ------------------------
3585 -- This is initialized the first time this routine is called. It records
3586 -- a value of 0,2,3,4,5 depending on what Str_Concat_n procedures are
3587 -- available in the run-time:
3588 --
3589 -- 0 None available
3590 -- 2 RE_Str_Concat available, RE_Str_Concat_3 not available
3591 -- 3 RE_Str_Concat/Concat_2 available, RE_Str_Concat_4 not available
3592 -- 4 RE_Str_Concat/Concat_2/3 available, RE_Str_Concat_5 not available
3593 -- 5 All routines including RE_Str_Concat_5 available
3596 -- Records if the routines RE_Str_Concat_CC/CS/SC are available. True if
3597 -- all three are available, False if any one of these is unavailable.
3601 -- List of operands to be concatenated
3604 -- Single operand for concatenation
3607 -- Node which is to be replaced by the result of concatenating
3608 -- the nodes in the list Opnds.
3611 -- Array type of concatenation result type
3614 -- Component type of concatenation represented by Cnode
3616 begin
3617 -- Initialize global variables showing run-time status
3628 else
3632 Char_Concat_Available :=
3634 and then
3636 and then
3640 -- Ensure validity of both operands
3644 -- If we are the left operand of a concatenation higher up the
3645 -- tree, then do nothing for now, since we want to deal with a
3646 -- series of concatenations as a unit.
3650 then
3654 -- We get here with a concatenation whose left operand may be a
3655 -- concatenation itself with a consistent type. We need to process
3656 -- these concatenation operands from left to right, which means
3657 -- from the deepest node in the tree to the highest node.
3664 -- Now Opnd is the deepest Opnd, and its parents are the concatenation
3665 -- nodes above, so now we process bottom up, doing the operations. We
3666 -- gather a string that is as long as possible up to five operands
3668 -- The outer loop runs more than once if there are more than five
3669 -- concatenations of type Standard.String, the most we handle for
3670 -- this case, or if more than one concatenation type is involved.
3676 -- The inner loop gathers concatenation operands. We gather any
3677 -- number of these in the non-string case, or if no concatenation
3678 -- routines are available for string (since in that case we will
3679 -- treat string like any other non-string case). Otherwise we only
3680 -- gather as many operands as can be handled by the available
3681 -- procedures in the run-time library (normally 5, but may be
3682 -- less for the configurable run-time case).
3686 or else
3688 or else
3690 Max_Available_String_Operands)
3693 loop
3698 -- Here we process the collected operands. First we convert
3699 -- singleton operands to singleton aggregates. This is skipped
3700 -- however for the case of two operands of type String, since
3701 -- we have special routines for these cases.
3707 or else not Char_Concat_Available
3708 then
3710 loop
3723 -- Now call appropriate continuation routine
3727 then
3729 else
3738 ------------------------
3739 -- Expand_N_Op_Divide --
3740 ------------------------
3748 begin
3751 -- Vax_Float is a special case
3758 -- N / 1 = N for integer types
3763 then
3768 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
3769 -- Is_Power_Of_2_For_Shift is set means that we know that our left
3770 -- operand is an unsigned integer, as required for this to work.
3775 -- We cannot do this transformation in configurable run time mode if we
3776 -- have 64-bit -- integers and long shifts are not available.
3778 and then
3781 then
3785 Right_Opnd =>
3791 -- Do required fixup of universal fixed operation
3798 -- Divisions with fixed-point results
3802 -- No special processing if Treat_Fixed_As_Integer is set,
3803 -- since from a semantic point of view such operations are
3804 -- simply integer operations and will be treated that way.
3809 else
3814 -- Other cases of division of fixed-point operands. Again we
3815 -- exclude the case where Treat_Fixed_As_Integer is set.
3820 then
3823 else
3828 -- Mixed-mode operations can appear in a non-static universal
3829 -- context, in which case the integer argument must be converted
3830 -- explicitly.
3834 then
3842 then
3848 -- Non-fixed point cases, do zero divide and overflow checks
3853 -- Check for 64-bit division available
3856 and then not Support_64_Bit_Divides_On_Target
3857 then
3863 --------------------
3864 -- Expand_N_Op_Eq --
3865 --------------------
3880 -- If a constructed equality exists for the type or for its parent,
3881 -- build and analyze call, adding conversions if the operation is
3882 -- inherited.
3885 -- Determines whether a type has a subcompoment of an unconstrained
3886 -- Unchecked_Union subtype. Typ is a record type.
3888 -------------------------
3889 -- Build_Equality_Call --
3890 -------------------------
3897 begin
3900 then
3905 -- If we have an Unchecked_Union, we need to add the inferred
3906 -- discriminant values as actuals in the function call. At this
3907 -- point, the expansion has determined that both operands have
3908 -- inferable discriminants.
3911 declare
3917 begin
3918 -- Per-object constrained selected components require special
3919 -- attention. If the enclosing scope of the component is an
3920 -- Unchecked_Union, we can not reference its discriminants
3921 -- directly. This is why we use the two extra parameters of
3922 -- the equality function of the enclosing Unchecked_Union.
3924 -- type UU_Type (Discr : Integer := 0) is
3925 -- . . .
3926 -- end record;
3927 -- pragma Unchecked_Union (UU_Type);
3929 -- 1. Unchecked_Union enclosing record:
3931 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
3932 -- . . .
3933 -- Comp : UU_Type (Discr);
3934 -- . . .
3935 -- end Enclosing_UU_Type;
3936 -- pragma Unchecked_Union (Enclosing_UU_Type);
3938 -- Obj1 : Enclosing_UU_Type;
3939 -- Obj2 : Enclosing_UU_Type (1);
3941 -- [. . .] Obj1 = Obj2 [. . .]
3943 -- Generated code:
3945 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
3947 -- A and B are the formal parameters of the equality function
3948 -- of Enclosing_UU_Type. The function always has two extra
3949 -- formals to capture the inferred discriminant values.
3951 -- 2. Non-Unchecked_Union enclosing record:
3953 -- type
3954 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
3955 -- is record
3956 -- . . .
3957 -- Comp : UU_Type (Discr);
3958 -- . . .
3959 -- end Enclosing_Non_UU_Type;
3961 -- Obj1 : Enclosing_Non_UU_Type;
3962 -- Obj2 : Enclosing_Non_UU_Type (1);
3964 -- . . . Obj1 = Obj2 . . .
3966 -- Generated code:
3968 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
3969 -- obj1.discr, obj2.discr)) then
3971 -- In this case we can directly reference the discriminants of
3972 -- the enclosing record.
3974 -- Lhs of equality
3977 and then Has_Per_Object_Constraint
3979 then
3980 -- Enclosing record is an Unchecked_Union, use formal A
3984 then
3985 Lhs_Discr_Val :=
3989 -- Enclosing record is of a non-Unchecked_Union type, it is
3990 -- possible to reference the discriminant.
3992 else
3993 Lhs_Discr_Val :=
3996 Selector_Name =>
3997 New_Copy
3998 (Get_Discriminant_Value
4000 Lhs_Type,
4004 -- Comment needed here ???
4006 else
4007 -- Infer the discriminant value
4009 Lhs_Discr_Val :=
4010 New_Copy
4011 (Get_Discriminant_Value
4013 Lhs_Type,
4017 -- Rhs of equality
4020 and then Has_Per_Object_Constraint
4022 then
4023 if Is_Unchecked_Union
4025 then
4026 Rhs_Discr_Val :=
4030 else
4031 Rhs_Discr_Val :=
4034 Selector_Name =>
4037 Rhs_Type,
4041 else
4042 Rhs_Discr_Val :=
4045 Rhs_Type,
4054 L_Exp,
4055 R_Exp,
4056 Lhs_Discr_Val,
4057 Rhs_Discr_Val)));
4060 -- Normal case, not an unchecked union
4062 else
4072 ------------------------------------
4073 -- Has_Unconstrained_UU_Component --
4074 ------------------------------------
4076 function Has_Unconstrained_UU_Component
4078 is
4084 function Component_Is_Unconstrained_UU
4086 -- Determines whether the subtype of the component is an
4087 -- unconstrained Unchecked_Union.
4089 function Variant_Is_Unconstrained_UU
4091 -- Determines whether a component of the variant has an unconstrained
4092 -- Unchecked_Union subtype.
4094 -----------------------------------
4095 -- Component_Is_Unconstrained_UU --
4096 -----------------------------------
4098 function Component_Is_Unconstrained_UU
4100 is
4101 begin
4106 declare
4110 begin
4111 -- Unconstrained nominal type. In the case of a constraint
4112 -- present, the node kind would have been N_Subtype_Indication.
4122 ---------------------------------
4123 -- Variant_Is_Unconstrained_UU --
4124 ---------------------------------
4126 function Variant_Is_Unconstrained_UU
4128 is
4131 begin
4136 declare
4139 begin
4142 -- One component is sufficent
4152 -- None of the components withing the variant were of
4153 -- unconstrained Unchecked_Union type.
4158 -- Start of processing for Has_Unconstrained_UU_Component
4160 begin
4168 -- Inspect available components
4171 declare
4174 begin
4177 -- One component is sufficent
4188 -- Inspect available components withing variants
4191 declare
4194 begin
4197 -- One component within a variant is sufficent
4208 -- Neither the available components, nor the components inside the
4209 -- variant parts were of an unconstrained Unchecked_Union subtype.
4214 -- Start of processing for Expand_N_Op_Eq
4216 begin
4226 -- It may happen in error situations that the underlying type is not
4227 -- set. The error will be detected later, here we just defend the
4228 -- expander code.
4236 -- Vax float types
4242 -- Boolean types (requiring handling of non-standard case)
4250 -- Array types
4254 -- If we are doing full validity checking, then expand out array
4255 -- comparisons to make sure that we check the array elements.
4258 declare
4260 Force_Validity_Checks;
4261 begin
4264 Expand_Array_Equality
4268 Bodies,
4269 Typl));
4275 -- Packed case where both operands are known aligned
4280 then
4283 -- Where the component type is elementary we can use a block bit
4284 -- comparison (if supported on the target) exception in the case
4285 -- of floating-point (negative zero issues require element by
4286 -- element comparison), and atomic types (where we must be sure
4287 -- to load elements independently) and possibly unaligned arrays.
4294 and then Support_Composite_Compare_On_Target
4295 then
4298 -- For composite and floating-point cases, expand equality loop
4299 -- to make sure of using proper comparisons for tagged types,
4300 -- and correctly handling the floating-point case.
4302 else
4304 Expand_Array_Equality
4308 Bodies,
4309 Typl));
4314 -- Record Types
4318 -- For tagged types, use the primitive "="
4322 -- If this is derived from an untagged private type completed
4323 -- with a tagged type, it does not have a full view, so we
4324 -- use the primitive operations of the private type.
4325 -- This check should no longer be necessary when these
4326 -- types receive their full views ???
4332 then
4333 -- Search for equality operation, checking that the
4334 -- operands have the same type. Note that we must find
4335 -- a matching entry, or something is very wrong!
4343 and then
4352 -- Find the type's predefined equality or an overriding
4353 -- user-defined equality. The reason for not simply calling
4354 -- Find_Prim_Op here is that there may be a user-defined
4355 -- overloaded equality op that precedes the equality that
4356 -- we want, so we have to explicitly search (e.g., there
4357 -- could be an equality with two different parameter types).
4359 else
4369 and then
4381 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
4382 -- predefined equality operator for a type which has a subcomponent
4383 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
4390 -- Prevent Gigi from generating incorrect code by rewriting the
4391 -- equality as a standard False.
4398 -- If we can infer the discriminants of the operands, we make a
4399 -- call to the TSS equality function.
4402 and then
4404 then
4405 Build_Equality_Call
4408 else
4409 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4410 -- the predefined equality operator for an Unchecked_Union type
4411 -- if either of the operands lack inferable discriminants.
4417 -- Prevent Gigi from generating incorrect code by rewriting
4418 -- the equality as a standard False.
4425 -- If a type support function is present (for complex cases), use it
4428 Build_Equality_Call
4431 -- Otherwise expand the component by component equality. Note that
4432 -- we never use block-bit coparisons for records, because of the
4433 -- problems with gaps. The backend will often be able to recombine
4434 -- the separate comparisons that we generate here.
4436 else
4447 -- If we still have an equality comparison (i.e. it was not rewritten
4448 -- in some way), then we can test if result is needed at compile time).
4455 -----------------------
4456 -- Expand_N_Op_Expon --
4457 -----------------------
4475 begin
4478 -- If either operand is of a private type, then we have the use of
4479 -- an intrinsic operator, and we get rid of the privateness, by using
4480 -- root types of underlying types for the actual operation. Otherwise
4481 -- the private types will cause trouble if we expand multiplications
4482 -- or shifts etc. We also do this transformation if the result type
4483 -- is different from the base type.
4486 or else
4488 or else
4490 or else
4492 then
4493 declare
4497 begin
4508 -- Test for case of known right argument
4513 -- We only fold small non-negative exponents. You might think we
4514 -- could fold small negative exponents for the real case, but we
4515 -- can't because we are required to raise Constraint_Error for
4516 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
4517 -- See ACVC test C4A012B.
4521 -- X ** 0 = 1 (or 1.0)
4526 else
4530 -- X ** 1 = X
4535 -- X ** 2 = X * X
4538 Xnode :=
4543 -- X ** 3 = X * X * X
4546 Xnode :=
4548 Left_Opnd =>
4554 -- X ** 4 ->
4555 -- En : constant base'type := base * base;
4556 -- ...
4557 -- En * En
4560 Temp :=
4568 Expression =>
4573 Xnode :=
4585 -- Case of (2 ** expression) appearing as an argument of an integer
4586 -- multiplication, or as the right argument of a division of a non-
4587 -- negative integer. In such cases we leave the node untouched, setting
4588 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
4589 -- of the higher level node converts it into a shift.
4596 and then not Ovflo
4598 then
4599 declare
4604 begin
4606 and then
4608 or else
4612 or else
4618 then
4625 -- Fall through if exponentiation must be done using a runtime routine
4627 -- First deal with modular case
4631 -- Non-binary case, we call the special exponentiation routine for
4632 -- the non-binary case, converting the argument to Long_Long_Integer
4633 -- and passing the modulus value. Then the result is converted back
4634 -- to the base type.
4644 Exp))));
4646 -- Binary case, in this case, we call one of two routines, either
4647 -- the unsigned integer case, or the unsigned long long integer
4648 -- case, with a final "and" operation to do the required mod.
4650 else
4653 else
4660 Left_Opnd =>
4665 Exp)),
4666 Right_Opnd =>
4671 -- Common exit point for modular type case
4676 -- Signed integer cases, done using either Integer or Long_Long_Integer.
4677 -- It is not worth having routines for Short_[Short_]Integer, since for
4678 -- most machines it would not help, and it would generate more code that
4679 -- might need certification in the HI-E case.
4681 -- In the integer cases, we have two routines, one for when overflow
4682 -- checks are required, and one when they are not required, since
4683 -- there is a real gain in ommitting checks on many machines.
4687 and then
4690 then
4695 else
4704 else
4708 -- Floating-point cases, always done using Long_Long_Float. We do not
4709 -- need separate routines for the overflow case here, since in the case
4710 -- of floating-point, we generate infinities anyway as a rule (either
4711 -- that or we automatically trap overflow), and if there is an infinity
4712 -- generated and a range check is required, the check will fail anyway.
4714 else
4720 -- Common processing for integer cases and floating-point cases.
4721 -- If we are in the right type, we can call runtime routine directly
4726 then
4732 -- Otherwise we have to introduce conversions (conversions are also
4733 -- required in the universal cases, since the runtime routine is
4734 -- typed using one of the standard types.
4736 else
4743 Exp))));
4749 exception
4754 --------------------
4755 -- Expand_N_Op_Ge --
4756 --------------------
4764 begin
4786 --------------------
4787 -- Expand_N_Op_Gt --
4788 --------------------
4796 begin
4818 --------------------
4819 -- Expand_N_Op_Le --
4820 --------------------
4828 begin
4850 --------------------
4851 -- Expand_N_Op_Lt --
4852 --------------------
4860 begin
4882 -----------------------
4883 -- Expand_N_Op_Minus --
4884 -----------------------
4890 begin
4893 if not Backend_Overflow_Checks_On_Target
4896 then
4897 -- Software overflow checking expands -expr into (0 - expr)
4906 -- Vax floating-point types case
4913 ---------------------
4914 -- Expand_N_Op_Mod --
4915 ---------------------
4933 begin
4939 -- Convert mod to rem if operands are known non-negative. We do this
4940 -- since it is quite likely that this will improve the quality of code,
4941 -- (the operation now corresponds to the hardware remainder), and it
4942 -- does not seem likely that it could be harmful.
4945 and then
4947 then
4953 -- Instead of reanalyzing the node we do the analysis manually.
4954 -- This avoids anomalies when the replacement is done in an
4955 -- instance and is epsilon more efficient.
4964 -- Otherwise, normal mod processing
4966 else
4971 -- Apply optimization x mod 1 = 0. We don't really need that with
4972 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
4973 -- certainly harmless.
4978 then
4984 -- Deal with annoying case of largest negative number remainder
4985 -- minus one. Gigi does not handle this case correctly, because
4986 -- it generates a divide instruction which may trap in this case.
4988 -- In fact the check is quite easy, if the right operand is -1,
4989 -- then the mod value is always 0, and we can just ignore the
4990 -- left operand completely in this case.
4992 -- The operand type may be private (e.g. in the expansion of an
4993 -- an intrinsic operation) so we must use the underlying type to
4994 -- get the bounds, and convert the literals explicitly.
4996 LLB :=
4997 Expr_Value
5001 and then
5003 then
5009 Right_Opnd =>
5022 --------------------------
5023 -- Expand_N_Op_Multiply --
5024 --------------------------
5043 begin
5046 -- Special optimizations for integer types
5050 -- N * 0 = 0 * N = 0 for integer types
5054 or else
5057 then
5063 -- N * 1 = 1 * N = N for integer types
5065 -- This optimisation is not done if we are going to
5066 -- rewrite the product 1 * 2 ** N to a shift.
5070 and then not Lp2
5071 then
5077 and then not Rp2
5078 then
5084 -- Deal with VAX float case
5091 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
5092 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5093 -- operand is an integer, as required for this to work.
5098 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
5103 Right_Opnd =>
5110 else
5114 Right_Opnd =>
5120 -- Same processing for the operands the other way round
5126 Right_Opnd =>
5132 -- Do required fixup of universal fixed operation
5139 -- Multiplications with fixed-point results
5143 -- No special processing if Treat_Fixed_As_Integer is set,
5144 -- since from a semantic point of view such operations are
5145 -- simply integer operations and will be treated that way.
5149 -- Case of fixed * integer => fixed
5154 -- Case of integer * fixed => fixed
5159 -- Case of fixed * fixed => fixed
5161 else
5166 -- Other cases of multiplication of fixed-point operands. Again
5167 -- we exclude the cases where Treat_Fixed_As_Integer flag is set.
5171 then
5174 else
5179 -- Mixed-mode operations can appear in a non-static universal
5180 -- context, in which case the integer argument must be converted
5181 -- explicitly.
5185 then
5192 then
5197 -- Non-fixed point cases, check software overflow checking required
5204 --------------------
5205 -- Expand_N_Op_Ne --
5206 --------------------
5208 -- Rewrite node as the negation of an equality operation, and reanalyze.
5209 -- The equality to be used is defined in the same scope and has the same
5210 -- signature. It must be set explicitly because in an instance it may not
5211 -- have the same visibility as in the generic unit.
5218 begin
5221 Neg :=
5223 Right_Opnd =>
5233 -- For navigation purposes, the inequality is treated as an implicit
5234 -- reference to the corresponding equality. Preserve the Comes_From_
5235 -- source flag so that the proper Xref entry is generated.
5243 ---------------------
5244 -- Expand_N_Op_Not --
5245 ---------------------
5247 -- If the argument is other than a Boolean array type, there is no
5248 -- special expansion required.
5250 -- For the packed case, we call the special routine in Exp_Pakd, except
5251 -- that if the component size is greater than one, we use the standard
5252 -- routine generating a gruesome loop (it is so peculiar to have packed
5253 -- arrays with non-standard Boolean representations anyway, so it does
5254 -- not matter that we do not handle this case efficiently).
5256 -- For the unpacked case (and for the special packed case where we have
5257 -- non standard Booleans, as discussed above), we generate and insert
5258 -- into the tree the following function definition:
5260 -- function Nnnn (A : arr) is
5261 -- B : arr;
5262 -- begin
5263 -- for J in a'range loop
5264 -- B (J) := not A (J);
5265 -- end loop;
5266 -- return B;
5267 -- end Nnnn;
5269 -- Here arr is the actual subtype of the parameter (and hence always
5270 -- constrained). Then we replace the not with a call to this function.
5286 begin
5289 -- For boolean operand, deal with non-standard booleans
5298 -- Only array types need any other processing
5304 -- Case of array operand. If bit packed with a component size of 1,
5305 -- handle it in Exp_Pakd if the operand is known to be aligned.
5310 then
5315 -- Case of array operand which is not bit-packed. If the context is
5316 -- a safe assignment, call in-place operation, If context is a larger
5317 -- boolean expression in the context of a safe assignment, expansion is
5318 -- done by enclosing operation.
5330 -- Special case the negation of a binary operation
5335 and then Safe_In_Place_Array_Op
5337 then
5344 then
5345 declare
5350 begin
5354 then
5355 -- (not A) op (not B) can be reduced to a single call
5361 then
5362 -- A xor (not B) can also be special-cased
5374 A_J :=
5379 B_J :=
5384 Loop_Statement :=
5388 Iteration_Scheme =>
5390 Loop_Parameter_Specification =>
5393 Discrete_Subtype_Definition =>
5408 Specification =>
5422 Handled_Statement_Sequence =>
5425 Loop_Statement,
5427 Expression =>
5438 --------------------
5439 -- Expand_N_Op_Or --
5440 --------------------
5445 begin
5459 ----------------------
5460 -- Expand_N_Op_Plus --
5461 ----------------------
5464 begin
5468 ---------------------
5469 -- Expand_N_Op_Rem --
5470 ---------------------
5487 begin
5494 -- Apply optimization x rem 1 = 0. We don't really need that with
5495 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
5496 -- certainly harmless.
5501 then
5507 -- Deal with annoying case of largest negative number remainder
5508 -- minus one. Gigi does not handle this case correctly, because
5509 -- it generates a divide instruction which may trap in this case.
5511 -- In fact the check is quite easy, if the right operand is -1,
5512 -- then the remainder is always 0, and we can just ignore the
5513 -- left operand completely in this case.
5518 -- The operand type may be private (e.g. in the expansion of an
5519 -- an intrinsic operation) so we must use the underlying type to
5520 -- get the bounds, and convert the literals explicitly.
5522 LLB :=
5523 Expr_Value
5526 -- Now perform the test, generating code only if needed
5529 and then
5531 then
5537 Right_Opnd =>
5551 -----------------------------
5552 -- Expand_N_Op_Rotate_Left --
5553 -----------------------------
5556 begin
5560 ------------------------------
5561 -- Expand_N_Op_Rotate_Right --
5562 ------------------------------
5565 begin
5569 ----------------------------
5570 -- Expand_N_Op_Shift_Left --
5571 ----------------------------
5574 begin
5578 -----------------------------
5579 -- Expand_N_Op_Shift_Right --
5580 -----------------------------
5583 begin
5587 ----------------------------------------
5588 -- Expand_N_Op_Shift_Right_Arithmetic --
5589 ----------------------------------------
5592 begin
5596 --------------------------
5597 -- Expand_N_Op_Subtract --
5598 --------------------------
5603 begin
5606 -- N - 0 = N for integer types
5611 then
5616 -- Arithemtic overflow checks for signed integer/fixed point types
5620 then
5623 -- Vax floating-point types case
5630 ---------------------
5631 -- Expand_N_Op_Xor --
5632 ---------------------
5637 begin
5651 ----------------------
5652 -- Expand_N_Or_Else --
5653 ----------------------
5655 -- Expand into conditional expression if Actions present, and also
5656 -- deal with optimizing case of arguments being True or False.
5665 begin
5666 -- Deal with non-standard booleans
5674 -- Check for cases of left argument is True or False
5678 -- If left argument is False, change (False or else Right) to Right.
5679 -- Any actions associated with Right will be executed unconditionally
5680 -- and can thus be inserted into the tree unconditionally.
5691 -- If left argument is True, change (True and then Right) to
5692 -- True. In this case we can forget the actions associated with
5693 -- Right, since they will never be executed.
5704 -- If Actions are present, we expand
5706 -- left or else right
5708 -- into
5710 -- if left then True else right end
5712 -- with the actions becoming the Else_Actions of the conditional
5713 -- expression. This conditional expression is then further expanded
5714 -- (and will eventually disappear)
5721 Left,
5723 Right)));
5731 -- No actions present, check for cases of right argument True/False
5735 -- Change (Left or else False) to Left. Note that we know there
5736 -- are no actions associated with the True operand, since we
5737 -- just checked for this case above.
5742 -- Change (Left or else True) to True, making sure to preserve
5743 -- any side effects associated with the Left operand.
5747 Rewrite
5755 -----------------------------------
5756 -- Expand_N_Qualified_Expression --
5757 -----------------------------------
5763 begin
5767 ---------------------------------
5768 -- Expand_N_Selected_Component --
5769 ---------------------------------
5771 -- If the selector is a discriminant of a concurrent object, rewrite the
5772 -- prefix to denote the corresponding record type.
5784 -- Gigi needs a temporary for prefixes that depend on a discriminant,
5785 -- unless the context of an assignment can provide size information.
5786 -- Don't we have a general routine that does this???
5788 -----------------------
5789 -- In_Left_Hand_Side --
5790 -----------------------
5793 begin
5801 -- Start of processing for Expand_N_Selected_Component
5803 begin
5804 -- Insert explicit dereference if required
5812 then
5819 -- Deal with discriminant check required
5823 -- Present the discrminant checking function to the backend,
5824 -- so that it can inline the call to the function.
5826 Add_Inlined_Body
5827 (Discriminant_Checking_Func
5830 -- Now reset the flag and generate the call
5836 -- Gigi cannot handle unchecked conversions that are the prefix of a
5837 -- selected component with discriminants. This must be checked during
5838 -- expansion, because during analysis the type of the selector is not
5839 -- known at the point the prefix is analyzed. If the conversion is the
5840 -- target of an assignment, then we cannot force the evaluation.
5845 then
5849 -- Remaining processing applies only if selector is a discriminant
5853 -- If the selector is a discriminant of a constrained record type,
5854 -- we may be able to rewrite the expression with the actual value
5855 -- of the discriminant, a useful optimization in some cases.
5860 then
5861 -- Do this optimization for discrete types only, and not for
5862 -- access types (access discriminants get us into trouble!)
5867 -- Don't do this on the left hand of an assignment statement.
5868 -- Normally one would think that references like this would
5869 -- not occur, but they do in generated code, and mean that
5870 -- we really do want to assign the discriminant!
5874 then
5877 -- Don't do this optimization for the prefix of an attribute
5878 -- or the operand of an object renaming declaration since these
5879 -- are contexts where we do not want the value anyway.
5884 then
5887 -- Don't do this optimization if we are within the code for a
5888 -- discriminant check, since the whole point of such a check may
5889 -- be to verify the condition on which the code below depends!
5894 -- Green light to see if we can do the optimization. There is
5895 -- still one condition that inhibits the optimization below
5896 -- but now is the time to check the particular discriminant.
5898 else
5899 -- Loop through discriminants to find the matching
5900 -- discriminant constraint to see if we can copy it.
5906 -- Check if this is the matching discriminant
5910 -- Here we have the matching discriminant. Check for
5911 -- the case of a discriminant of a component that is
5912 -- constrained by an outer discriminant, which cannot
5913 -- be optimized away.
5915 if
5916 Denotes_Discriminant
5918 then
5921 -- In the context of a case statement, the expression
5922 -- may have the base type of the discriminant, and we
5923 -- need to preserve the constraint to avoid spurious
5924 -- errors on missing cases.
5928 then
5931 Subtype_Mark =>
5933 Expression =>
5937 -- In case that comes out as a static expression,
5938 -- reset it (a selected component is never static).
5943 -- Otherwise we can just copy the constraint, but the
5944 -- result is certainly not static! In some cases the
5945 -- discriminant constraint has been analyzed in the
5946 -- context of the original subtype indication, but for
5947 -- itypes the constraint might not have been analyzed
5948 -- yet, and this must be done now.
5950 else
5962 -- Note: the above loop should always find a matching
5963 -- discriminant, but if it does not, we just missed an
5964 -- optimization due to some glitch (perhaps a previous
5965 -- error), so ignore.
5970 -- The only remaining processing is in the case of a discriminant of
5971 -- a concurrent object, where we rewrite the prefix to denote the
5972 -- corresponding record type. If the type is derived and has renamed
5973 -- discriminants, use corresponding discriminant, which is the one
5974 -- that appears in the corresponding record.
5984 then
5988 New_N :=
5990 Prefix =>
6000 --------------------
6001 -- Expand_N_Slice --
6002 --------------------
6011 -- Check whether the argument is an actual for a procedure call,
6012 -- in which case the expansion of a bit-packed slice is deferred
6013 -- until the call itself is expanded. The reason this is required
6014 -- is that we might have an IN OUT or OUT parameter, and the copy out
6015 -- is essential, and that copy out would be missed if we created a
6016 -- temporary here in Expand_N_Slice. Note that we don't bother
6017 -- to test specifically for an IN OUT or OUT mode parameter, since it
6018 -- is a bit tricky to do, and it is harmless to defer expansion
6019 -- in the IN case, since the call processing will still generate the
6020 -- appropriate copy in operation, which will take care of the slice.
6023 -- Create a named variable for the value of the slice, in
6024 -- cases where the back-end cannot handle it properly, e.g.
6025 -- when packed types or unaligned slices are involved.
6027 -------------------------
6028 -- Is_Procedure_Actual --
6029 -------------------------
6034 begin
6035 loop
6036 -- If our parent is a procedure call we can return
6041 -- If our parent is a type conversion, keep climbing the
6042 -- tree, since a type conversion can be a procedure actual.
6043 -- Also keep climbing if parameter association or a qualified
6044 -- expression, since these are additional cases that do can
6045 -- appear on procedure actuals.
6050 then
6053 -- Any other case is not what we are looking for
6055 else
6061 --------------------
6062 -- Make_Temporary --
6063 --------------------
6069 begin
6070 Decl :=
6078 Decl,
6087 -- Start of processing for Expand_N_Slice
6089 begin
6090 -- Special handling for access types
6103 -- Range checks are potentially also needed for cases involving
6104 -- a slice indexed by a subtype indication, but Do_Range_Check
6105 -- can currently only be set for expressions ???
6111 then
6115 -- The remaining case to be handled is packed slices. We can leave
6116 -- packed slices as they are in the following situations:
6118 -- 1. Right or left side of an assignment (we can handle this
6119 -- situation correctly in the assignment statement expansion).
6121 -- 2. Prefix of indexed component (the slide is optimized away
6122 -- in this case, see the start of Expand_N_Slice.
6124 -- 3. Object renaming declaration, since we want the name of
6125 -- the slice, not the value.
6127 -- 4. Argument to procedure call, since copy-in/copy-out handling
6128 -- may be required, and this is handled in the expansion of
6129 -- call itself.
6131 -- 5. Prefix of an address attribute (this is an error which
6132 -- is caught elsewhere, and the expansion would intefere
6133 -- with generating the error message).
6137 -- Apply transformation for actuals of a function call,
6138 -- where Expand_Actuals is not used.
6142 then
6143 Make_Temporary;
6149 then
6155 then
6160 then
6163 else
6164 Make_Temporary;
6168 ------------------------------
6169 -- Expand_N_Type_Conversion --
6170 ------------------------------
6179 -- This is called in the case of record and array type conversions
6180 -- to see if there is a change of representation to be handled.
6181 -- Change of representation is actually handled at the assignment
6182 -- statement level, and what this procedure does is rewrite node N
6183 -- conversion as an assignment to temporary. If there is no change
6184 -- of representation, then the conversion node is unchanged.
6187 -- Handles generation of range check for real target value
6189 -----------------------------------
6190 -- Handle_Changed_Representation --
6191 -----------------------------------
6201 begin
6202 -- Nothing to do if no change of representation
6207 -- The real change of representation work is done by the assignment
6208 -- statement processing. So if this type conversion is appearing as
6209 -- the expression of an assignment statement, nothing needs to be
6210 -- done to the conversion.
6215 -- Otherwise we need to generate a temporary variable, and do the
6216 -- change of representation assignment into that temporary variable.
6217 -- The conversion is then replaced by a reference to this variable.
6219 else
6222 -- If type is unconstrained we have to add a constraint,
6223 -- copied from the actual value of the left hand side.
6238 Selector_Name =>
6249 -- We convert the bounds explicitly. We use an unchecked
6250 -- conversion because bounds checks are done elsewhere.
6254 Low_Bound =>
6257 Prefix =>
6258 Duplicate_Subexpr_No_Checks
6264 High_Bound =>
6267 Prefix =>
6268 Duplicate_Subexpr_No_Checks
6282 Odef :=
6285 Constraint =>
6291 Decl :=
6298 -- Insert required actions. It is essential to suppress checks
6299 -- since we have suppressed default initialization, which means
6300 -- that the variable we create may have no discriminants.
6303 New_List (
6304 Decl,
6315 ----------------------
6316 -- Real_Range_Check --
6317 ----------------------
6319 -- Case of conversions to floating-point or fixed-point. If range
6320 -- checks are enabled and the target type has a range constraint,
6321 -- we convert:
6323 -- typ (x)
6325 -- to
6327 -- Tnn : typ'Base := typ'Base (x);
6328 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
6329 -- Tnn
6331 -- This is necessary when there is a conversion of integer to float
6332 -- or to fixed-point to ensure that the correct checks are made. It
6333 -- is not necessary for float to float where it is enough to simply
6334 -- set the Do_Range_Check flag.
6344 begin
6345 -- Nothing to do if conversion was rewritten
6351 -- Nothing to do if range checks suppressed, or target has the
6352 -- same range as the base type (or is the base type).
6356 and then
6358 then
6362 -- Nothing to do if expression is an entity on which checks
6363 -- have been suppressed.
6367 then
6371 -- Nothing to do if bounds are all static and we can tell that
6372 -- the expression is within the bounds of the target. Note that
6373 -- if the operand is of an unconstrained floating-point type,
6374 -- then we do not trust it to be in range (might be infinite)
6376 declare
6380 begin
6387 then
6388 declare
6394 begin
6398 else
6406 then
6414 -- For float to float conversions, we are done
6417 and then
6419 then
6423 -- Otherwise rewrite the conversion as described above
6426 Rewrite
6430 -- Enable overflow except in the case of integer to float
6431 -- conversions, where it is never required, since we can
6432 -- never have overflow in this case.
6438 Tnn :=
6449 Condition =>
6451 Left_Opnd =>
6454 Right_Opnd =>
6457 Prefix =>
6460 Right_Opnd =>
6463 Right_Opnd =>
6466 Prefix =>
6474 -- Start of processing for Expand_N_Type_Conversion
6476 begin
6477 -- Nothing at all to do if conversion is to the identical type
6478 -- so remove the conversion completely, it is useless.
6485 -- Deal with Vax floating-point cases
6492 -- Nothing to do if this is the second argument of read. This
6493 -- is a "backwards" conversion that will be handled by the
6494 -- specialized code in attribute processing.
6499 then
6503 -- Here if we may need to expand conversion
6505 -- Special case of converting from non-standard boolean type
6509 then
6515 -- Case of converting to an access type
6519 -- Apply an accessibility check if the operand is an
6520 -- access parameter. Note that other checks may still
6521 -- need to be applied below (such as tagged type checks).
6526 then
6529 -- If the level of the operand type is statically deeper
6530 -- then the level of the target type, then force Program_Error.
6531 -- Note that this can only occur for cases where the attribute
6532 -- is within the body of an instantiation (otherwise the
6533 -- conversion will already have been rejected as illegal).
6534 -- Note: warnings are issued by the analyzer for the instance
6535 -- cases.
6537 elsif In_Instance_Body
6540 then
6546 -- When the operand is a selected access discriminant
6547 -- the check needs to be made against the level of the
6548 -- object denoted by the prefix of the selected name.
6549 -- Force Program_Error for this case as well (this
6550 -- accessibility violation can only happen if within
6551 -- the body of an instantiation).
6553 elsif In_Instance_Body
6558 then
6566 -- Case of conversions of tagged types and access to tagged types
6568 -- When needed, that is to say when the expression is class-wide,
6569 -- Add runtime a tag check for (strict) downward conversion by using
6570 -- the membership test, generating:
6572 -- [constraint_error when Operand not in Target_Type'Class]
6574 -- or in the access type case
6576 -- [constraint_error
6577 -- when Operand /= null
6578 -- and then Operand.all not in
6579 -- Designated_Type (Target_Type)'Class]
6584 then
6585 -- Do not do any expansion in the access type case if the
6586 -- parent is a renaming, since this is an error situation
6587 -- which will be caught by Sem_Ch8, and the expansion can
6588 -- intefere with this error check.
6592 then
6596 -- Oherwise, proceed with processing tagged conversion
6598 declare
6604 begin
6609 else
6616 and then Is_Ancestor
6618 Actual_Target_Type)
6620 then
6621 -- The conversion is valid for any descendant of the
6622 -- target type
6627 Cond :=
6629 Left_Opnd =>
6634 Right_Opnd =>
6636 Left_Opnd =>
6638 Prefix =>
6640 Right_Opnd =>
6643 else
6644 Cond :=
6647 Right_Opnd =>
6656 declare
6658 begin
6659 Conv :=
6669 -- Case of other access type conversions
6674 -- Case of conversions from a fixed-point type
6676 -- These conversions require special expansion and processing, found
6677 -- in the Exp_Fixd package. We ignore cases where Conversion_OK is
6678 -- set, since from a semantic point of view, these are simple integer
6679 -- conversions, which do not need further processing.
6683 then
6684 -- We should never see universal fixed at this case, since the
6685 -- expansion of the constituent divide or multiply should have
6686 -- eliminated the explicit mention of universal fixed.
6690 -- Check for special case of the conversion to universal real
6691 -- that occurs as a result of the use of a round attribute.
6692 -- In this case, the real type for the conversion is taken
6693 -- from the target type of the Round attribute and the
6694 -- result must be marked as rounded.
6699 then
6704 -- Otherwise do correct fixed-conversion, but skip these if the
6705 -- Conversion_OK flag is set, because from a semantic point of
6706 -- view these are simple integer conversions needing no further
6707 -- processing (the backend will simply treat them as integers)
6712 Real_Range_Check;
6717 else
6720 Real_Range_Check;
6724 -- Case of conversions to a fixed-point type
6726 -- These conversions require special expansion and processing, found
6727 -- in the Exp_Fixd package. Again, ignore cases where Conversion_OK
6728 -- is set, since from a semantic point of view, these are simple
6729 -- integer conversions, which do not need further processing.
6733 then
6736 Real_Range_Check;
6737 else
6740 Real_Range_Check;
6743 -- Case of float-to-integer conversions
6745 -- We also handle float-to-fixed conversions with Conversion_OK set
6746 -- since semantically the fixed-point target is treated as though it
6747 -- were an integer in such cases.
6750 and then
6752 or else
6754 then
6755 -- Special processing required if the conversion is the expression
6756 -- of a Truncation attribute reference. In this case we replace:
6758 -- ityp (ftyp'Truncation (x))
6760 -- by
6762 -- ityp (x)
6764 -- with the Float_Truncate flag set. This is clearly more efficient
6768 then
6774 -- One more check here, gcc is still not able to do conversions of
6775 -- this type with proper overflow checking, and so gigi is doing an
6776 -- approximation of what is required by doing floating-point compares
6777 -- with the end-point. But that can lose precision in some cases, and
6778 -- give a wrong result. Converting the operand to Long_Long_Float is
6779 -- helpful, but still does not catch all cases with 64-bit integers
6780 -- on targets with only 64-bit floats ???
6785 Subtype_Mark =>
6787 Expression =>
6795 -- Case of array conversions
6797 -- Expansion of array conversions, add required length/range checks
6798 -- but only do this if there is no change of representation. For
6799 -- handling of this case, see Handle_Changed_Representation.
6805 else
6809 Handle_Changed_Representation;
6811 -- Case of conversions of discriminated types
6813 -- Add required discriminant checks if target is constrained. Again
6814 -- this change is skipped if we have a change of representation.
6818 then
6820 Handle_Changed_Representation;
6822 -- Case of all other record conversions. The only processing required
6823 -- is to check for a change of representation requiring the special
6824 -- assignment processing.
6828 -- Ada 2005 (AI-216): Program_Error is raised when converting from
6829 -- a derived Unchecked_Union type to an unconstrained non-Unchecked_
6830 -- Union type if the operand lacks inferable discriminants.
6837 then
6838 -- To prevent Gigi from generating illegal code, we make a
6839 -- Program_Error node, but we give it the target type of the
6840 -- conversion.
6842 declare
6846 begin
6851 else
6852 Handle_Changed_Representation;
6855 -- Case of conversions of enumeration types
6859 -- Special processing is required if there is a change of
6860 -- representation (from enumeration representation clauses)
6864 -- Convert: x(y) to x'val (ytyp'val (y))
6879 -- Case of conversions to floating-point
6882 Real_Range_Check;
6884 -- The remaining cases require no front end processing
6886 else
6890 -- At this stage, either the conversion node has been transformed
6891 -- into some other equivalent expression, or left as a conversion
6892 -- that can be handled by Gigi. The conversions that Gigi can handle
6893 -- are the following:
6895 -- Conversions with no change of representation or type
6897 -- Numeric conversions involving integer values, floating-point
6898 -- values, and fixed-point values. Fixed-point values are allowed
6899 -- only if Conversion_OK is set, i.e. if the fixed-point values
6900 -- are to be treated as integers.
6902 -- No other conversions should be passed to Gigi
6904 -- Check: are these rules stated in sinfo??? if so, why restate here???
6906 -- The only remaining step is to generate a range check if we still
6907 -- have a type conversion at this stage and Do_Range_Check is set.
6908 -- For now we do this only for conversions of discrete types.
6912 then
6913 declare
6918 begin
6921 then
6924 -- Before we do a range check, we have to deal with treating
6925 -- a fixed-point operand as an integer. The way we do this
6926 -- is simply to do an unchecked conversion to an appropriate
6927 -- integer type large enough to hold the result.
6929 -- This code is not active yet, because we are only dealing
6930 -- with discrete types so far ???
6934 then
6939 else
6946 -- Reset overflow flag, since the range check will include
6947 -- dealing with possible overflow, and generate the check
6948 -- If Address is either source or target type, suppress
6949 -- range check to avoid typing anomalies when it is a visible
6950 -- integer type.
6955 then
6956 Generate_Range_Check
6964 -----------------------------------
6965 -- Expand_N_Unchecked_Expression --
6966 -----------------------------------
6968 -- Remove the unchecked expression node from the tree. It's job was simply
6969 -- to make sure that its constituent expression was handled with checks
6970 -- off, and now that that is done, we can remove it from the tree, and
6971 -- indeed must, since gigi does not expect to see these nodes.
6976 begin
6981 ----------------------------------------
6982 -- Expand_N_Unchecked_Type_Conversion --
6983 ----------------------------------------
6985 -- If this cannot be handled by Gigi and we haven't already made
6986 -- a temporary for it, do it now.
6993 begin
6994 -- If we have a conversion of a compile time known value to a target
6995 -- type and the value is in range of the target type, then we can simply
6996 -- replace the construct by an integer literal of the correct type. We
6997 -- only apply this to integer types being converted. Possibly it may
6998 -- apply in other cases, but it is too much trouble to worry about.
7000 -- Note that we do not do this transformation if the Kill_Range_Check
7001 -- flag is set, since then the value may be outside the expected range.
7002 -- This happens in the Normalize_Scalars case.
7008 then
7009 declare
7012 begin
7014 and then
7016 and then
7018 and then
7020 then
7023 -- If Address is the target type, just set the type
7024 -- to avoid a spurious type error on the literal when
7025 -- Address is a visible integer type.
7029 else
7038 -- Nothing to do if conversion is safe
7044 -- Otherwise force evaluation unless Assignment_OK flag is set (this
7045 -- flag indicates ??? -- more comments needed here)
7049 else
7054 ----------------------------
7055 -- Expand_Record_Equality --
7056 ----------------------------
7058 -- For non-variant records, Equality is expanded when needed into:
7060 -- and then Lhs.Discr1 = Rhs.Discr1
7061 -- and then ...
7062 -- and then Lhs.Discrn = Rhs.Discrn
7063 -- and then Lhs.Cmp1 = Rhs.Cmp1
7064 -- and then ...
7065 -- and then Lhs.Cmpn = Rhs.Cmpn
7067 -- The expression is folded by the back-end for adjacent fields. This
7068 -- function is called for tagged record in only one occasion: for imple-
7069 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
7070 -- otherwise the primitive "=" is used directly.
7072 function Expand_Record_Equality
7078 is
7087 -- Return the first field to compare beginning with C, skipping the
7088 -- inherited components.
7090 ----------------------
7091 -- Suitable_Element --
7092 ----------------------
7095 begin
7101 then
7106 then
7111 then
7114 else
7119 -- Start of processing for Expand_Record_Equality
7121 begin
7122 -- Generates the following code: (assuming that Typ has one Discr and
7123 -- component C2 is also a record)
7125 -- True
7126 -- and then Lhs.Discr1 = Rhs.Discr1
7127 -- and then Lhs.C1 = Rhs.C1
7128 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
7129 -- and then ...
7130 -- and then Lhs.Cmpn = Rhs.Cmpn
7136 declare
7141 begin
7146 else
7151 Check :=
7153 Lhs =>
7157 Rhs =>
7163 -- If some (sub)component is an unchecked_union, the whole
7164 -- operation will raise program error.
7170 else
7171 Result :=
7184 -------------------------------------
7185 -- Fixup_Universal_Fixed_Operation --
7186 -------------------------------------
7191 begin
7192 -- We must have a type conversion immediately above us
7196 -- Normally the type conversion gives our target type. The exception
7197 -- occurs in the case of the Round attribute, where the conversion
7198 -- will be to universal real, and our real type comes from the Round
7199 -- attribute (as well as an indication that we must round the result)
7203 then
7207 -- Normal case where type comes from conversion above us
7209 else
7214 ------------------------------
7215 -- Get_Allocator_Final_List --
7216 ------------------------------
7218 function Get_Allocator_Final_List
7222 is
7226 -- The entity whose finalisation list must be used to attach the
7227 -- allocated object.
7229 begin
7232 in N_Subprogram_Specification
7233 then
7234 -- If the context is an access parameter, we need to create
7235 -- a non-anonymous access type in order to have a usable
7236 -- final list, because there is otherwise no pool to which
7237 -- the allocated object can belong. We create both the type
7238 -- and the finalization chain here, because freezing an
7239 -- internal type does not create such a chain. The Final_Chain
7240 -- that is thus created is shared by the access parameter.
7246 Type_Definition =>
7248 Subtype_Indication =>
7254 else
7255 -- Case of an access discriminant, or (Ada 2005) of
7256 -- an anonymous access component: find the final list
7257 -- associated with the scope of the type.
7266 ---------------------------------
7267 -- Has_Inferable_Discriminants --
7268 ---------------------------------
7273 -- Determines whether the left-most prefix of a selected component is a
7274 -- formal parameter in a subprogram. Assumes N is a selected component.
7276 --------------------------------
7277 -- Prefix_Is_Formal_Parameter --
7278 --------------------------------
7283 begin
7284 -- Move to the left-most prefix by climbing up the tree
7288 loop
7295 -- Start of processing for Has_Inferable_Discriminants
7297 begin
7298 -- For identifiers and indexed components, it is sufficent to have a
7299 -- constrained Unchecked_Union nominal subtype.
7302 or else
7304 then
7306 and then
7309 -- For selected components, the subtype of the selector must be a
7310 -- constrained Unchecked_Union. If the component is subject to a
7311 -- per-object constraint, then the enclosing object must have inferable
7312 -- discriminants.
7317 -- A small hack. If we have a per-object constrained selected
7318 -- component of a formal parameter, return True since we do not
7319 -- know the actual parameter association yet.
7325 -- Otherwise, check the enclosing object and the selector
7328 and then
7332 -- The call to Has_Inferable_Discriminants will determine whether
7333 -- the selector has a constrained Unchecked_Union nominal type.
7337 -- A qualified expression has inferable discriminants if its subtype
7338 -- mark is a constrained Unchecked_Union subtype.
7342 and then
7350 -------------------------------
7351 -- Insert_Dereference_Action --
7352 -------------------------------
7361 -- Return true if type of P is derived from Checked_Pool;
7363 -----------------------------
7364 -- Is_Checked_Storage_Pool --
7365 -----------------------------
7370 begin
7379 else
7387 -- Start of processing for Insert_Dereference_Action
7389 begin
7394 then
7405 -- Pool
7409 -- Storage_Address. We use the attribute Pool_Address,
7410 -- which uses the pointer itself to find the address of
7411 -- the object, and which handles unconstrained arrays
7412 -- properly by computing the address of the template.
7413 -- i.e. the correct address of the corresponding allocation.
7419 -- Size_In_Storage_Elements
7422 Left_Opnd =>
7424 Prefix =>
7428 Right_Opnd =>
7431 -- Alignment
7434 Prefix =>
7439 exception
7444 ------------------------------
7445 -- Make_Array_Comparison_Op --
7446 ------------------------------
7448 -- This is a hand-coded expansion of the following generic function:
7450 -- generic
7451 -- type elem is (<>);
7452 -- type index is (<>);
7453 -- type a is array (index range <>) of elem;
7454 --
7455 -- function Gnnn (X : a; Y: a) return boolean is
7456 -- J : index := Y'first;
7457 --
7458 -- begin
7459 -- if X'length = 0 then
7460 -- return false;
7461 --
7462 -- elsif Y'length = 0 then
7463 -- return true;
7464 --
7465 -- else
7466 -- for I in X'range loop
7467 -- if X (I) = Y (J) then
7468 -- if J = Y'last then
7469 -- exit;
7470 -- else
7471 -- J := index'succ (J);
7472 -- end if;
7473 --
7474 -- else
7475 -- return X (I) > Y (J);
7476 -- end if;
7477 -- end loop;
7478 --
7479 -- return X'length > Y'length;
7480 -- end if;
7481 -- end Gnnn;
7483 -- Note that since we are essentially doing this expansion by hand, we
7484 -- do not need to generate an actual or formal generic part, just the
7485 -- instantiated function itself.
7487 function Make_Array_Comparison_Op
7490 is
7511 begin
7512 -- if J = Y'last then
7513 -- exit;
7514 -- else
7515 -- J := index'succ (J);
7516 -- end if;
7518 Inner_If :=
7520 Condition =>
7523 Right_Opnd =>
7531 Else_Statements =>
7532 New_List (
7535 Expression =>
7541 -- if X (I) = Y (J) then
7542 -- if ... end if;
7543 -- else
7544 -- return X (I) > Y (J);
7545 -- end if;
7547 Loop_Body :=
7549 Condition =>
7551 Left_Opnd =>
7556 Right_Opnd =>
7565 Expression =>
7567 Left_Opnd =>
7572 Right_Opnd =>
7578 -- for I in X'range loop
7579 -- if ... end if;
7580 -- end loop;
7582 Loop_Statement :=
7586 Iteration_Scheme =>
7588 Loop_Parameter_Specification =>
7591 Discrete_Subtype_Definition =>
7598 -- if X'length = 0 then
7599 -- return false;
7600 -- elsif Y'length = 0 then
7601 -- return true;
7602 -- else
7603 -- for ... loop ... end loop;
7604 -- return X'length > Y'length;
7605 -- end if;
7607 Length1 :=
7612 Length2 :=
7617 Final_Expr :=
7622 If_Stat :=
7624 Condition =>
7626 Left_Opnd =>
7630 Right_Opnd =>
7633 Then_Statements =>
7634 New_List (
7640 Condition =>
7642 Left_Opnd =>
7646 Right_Opnd =>
7649 Then_Statements =>
7650 New_List (
7655 Loop_Statement,
7659 -- (X : a; Y: a)
7670 -- function Gnnn (...) return boolean is
7671 -- J : index := Y'first;
7672 -- begin
7673 -- if ... end if;
7674 -- end Gnnn;
7678 Func_Body :=
7680 Specification =>
7690 Expression =>
7695 Handled_Statement_Sequence =>
7703 ---------------------------
7704 -- Make_Boolean_Array_Op --
7705 ---------------------------
7707 -- For logical operations on boolean arrays, expand in line the
7708 -- following, replacing 'and' with 'or' or 'xor' where needed:
7710 -- function Annn (A : typ; B: typ) return typ is
7711 -- C : typ;
7712 -- begin
7713 -- for J in A'range loop
7714 -- C (J) := A (J) op B (J);
7715 -- end loop;
7716 -- return C;
7717 -- end Annn;
7719 -- Here typ is the boolean array type
7721 function Make_Boolean_Array_Op
7724 is
7742 begin
7743 A_J :=
7748 B_J :=
7753 C_J :=
7759 Op :=
7765 Op :=
7770 else
7771 Op :=
7777 Loop_Statement :=
7781 Iteration_Scheme =>
7783 Loop_Parameter_Specification =>
7786 Discrete_Subtype_Definition =>
7805 Func_Name :=
7809 Func_Body :=
7811 Specification =>
7822 Handled_Statement_Sequence =>
7825 Loop_Statement,
7832 ------------------------
7833 -- Rewrite_Comparison --
7834 ------------------------
7842 -- Res indicates if compare outcome can be determined at compile time
7847 begin
7888 ----------------------------
7889 -- Safe_In_Place_Array_Op --
7890 ----------------------------
7892 function Safe_In_Place_Array_Op
7896 is
7900 -- Operand is safe if it cannot overlap part of the target of the
7901 -- operation. If the operand and the target are identical, the operand
7902 -- is safe. The operand can be empty in the case of negation.
7905 -- Check that N is a stand-alone entity
7907 ------------------
7908 -- Is_Unaliased --
7909 ------------------
7912 begin
7913 return
7919 ---------------------
7920 -- Is_Safe_Operand --
7921 ---------------------
7924 begin
7933 then
7937 return
7944 else
7949 -- Start of processing for Is_Safe_In_Place_Array_Op
7951 begin
7952 -- We skip this processing if the component size is not the
7953 -- same as a system storage unit (since at least for NOT
7954 -- this would cause problems).
7959 -- Cannot do in place stuff on Java_VM since cannot pass addresses
7964 -- Cannot do in place stuff if non-standard Boolean representation
7971 else
7974 return
7980 -----------------------
7981 -- Tagged_Membership --
7982 -----------------------
7984 -- There are two different cases to consider depending on whether
7985 -- the right operand is a class-wide type or not. If not we just
7986 -- compare the actual tag of the left expr to the target type tag:
7987 --
7988 -- Left_Expr.Tag = Right_Type'Tag;
7989 --
7990 -- If it is a class-wide type we use the RT function CW_Membership which
7991 -- is usually implemented by looking in the ancestor tables contained in
7992 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
8003 begin
8011 Obj_Tag :=
8014 Selector_Name =>
8018 return
8022 Obj_Tag,
8023 New_Reference_To
8026 Loc)));
8027 else
8028 return
8031 Right_Opnd =>
8032 New_Reference_To
8038 ------------------------------
8039 -- Unary_Op_Validity_Checks --
8040 ------------------------------
8043 begin