| blob | 2fafd48de8ef100c46eb1c7cdc4234cd58235459 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * T R A N S *
6 * *
7 * C Implementation File *
8 * *
9 * *
10 * Copyright (C) 1992-2002, Free Software Foundation, Inc. *
11 * *
12 * GNAT is free software; you can redistribute it and/or modify it under *
13 * terms of the GNU General Public License as published by the Free Soft- *
14 * ware Foundation; either version 2, or (at your option) any later ver- *
15 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
16 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
18 * for more details. You should have received a copy of the GNU General *
19 * Public License distributed with GNAT; see file COPYING. If not, write *
20 * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, *
21 * MA 02111-1307, USA. *
22 * *
23 * GNAT was originally developed by the GNAT team at New York University. *
24 * It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). *
25 * *
26 ****************************************************************************/
67 /* Current filename without path. */
70 /* Flag indicating whether file names are discarded in exception messages */
73 /* If true, then gigi is being called on an analyzed but unexpanded
74 tree, and the only purpose of the call is to properly annotate
75 types with representation information. */
78 /* List of TREE_LIST nodes representing a block stack. TREE_VALUE
79 of each gives the variable used for the setjmp buffer in the current
80 block, if any. TREE_PURPOSE gives the bottom condition for a loop,
81 if this block is for a loop. The latter is only used to save the tree
82 over GC. */
83 tree gnu_block_stack;
85 /* List of TREE_LIST nodes representing a stack of exception pointer
86 variables. TREE_VALUE is the VAR_DECL that stores the address of
87 the raised exception. Nonzero means we are in an exception
88 handler. Not used in the zero-cost case. */
91 /* Map GNAT tree codes to GCC tree codes for simple expressions. */
94 /* Current node being treated, in case gigi_abort called. */
95 Node_Id error_gnat_node;
97 /* Variable that stores a list of labels to be used as a goto target instead of
98 a return in some functions. See processing for N_Subprogram_Body. */
122 /* Constants for +0.5 and -0.5 for float-to-integer rounding. */
125 \f
126 /* This is the main program of the back-end. It sets up all the table
127 structures and then generates code. */
129 void
134 Node_Id gnat_root;
145 Int number_units ATTRIBUTE_UNUSED;
147 Entity_Id standard_integer;
148 Entity_Id standard_long_long_float;
149 Entity_Id standard_exception_type;
150 Int gigi_operating_mode;
151 {
152 tree gnu_standard_long_long_float;
153 tree gnu_standard_exception_type;
168 /* See if we should discard file names in exception messages. */
176 /* Initialize ourselves. */
181 /* Enable GNAT stack checking method if needed */
185 /* Save the type we made for integer as the type for Standard.Integer.
186 Then make the rest of the standard types. Note that some of these
187 may be subtypes. */
196 gnu_standard_long_long_float
198 gnu_standard_exception_type
203 /* Process any Pragma Ident for the main unit. */
204 #ifdef ASM_OUTPUT_IDENT
206 ASM_OUTPUT_IDENT
209 #endif
211 /* If we are using the GCC exception mechanism, let GCC know. */
216 }
218 \f
219 /* This function is the driver of the GNAT to GCC tree transformation process.
220 GNAT_NODE is the root of some gnat tree. It generates code for that
221 part of the tree. */
223 void
225 Node_Id gnat_node;
226 {
227 tree gnu_root;
229 /* Save node number in case error */
234 /* This should just generate code, not return a value. If it returns
235 a value, something is wrong. */
238 }
240 /* GNAT_NODE is the root of some GNAT tree. Return the root of the GCC
241 tree corresponding to that GNAT tree. Normally, no code is generated.
242 We just return an equivalent tree which is used elsewhere to generate
243 code. */
245 tree
247 Node_Id gnat_node;
248 {
249 tree gnu_root;
251 /* Save node number in case error */
256 /* If we got no code as a result, something is wrong. */
261 }
262 \f
263 /* This function is the driver of the GNAT to GCC tree transformation process.
264 It is the entry point of the tree transformer. GNAT_NODE is the root of
265 some GNAT tree. Return the root of the corresponding GCC tree or
266 error_mark_node to signal that there is no GCC tree to return.
268 The latter is the case if only code generation actions have to be performed
269 like in the case of if statements, loops, etc. This routine is wrapped
270 in the above two routines for most purposes. */
272 static tree
274 Node_Id gnat_node;
275 {
278 tree gnu_expr;
280 Node_Id gnat_temp;
281 Entity_Id gnat_temp_type;
283 /* Set input_file_name and lineno from the Sloc in the GNAT tree. */
286 /* If this is a Statement and we are at top level, we add the statement
287 as an elaboration for a null tree. That will cause it to be placed
288 in the elaboration procedure. */
301 {
305 }
307 /* If this node is a non-static subexpression and we are only
308 annotating types, make this into a NULL_EXPR for non-VOID types
309 and error_mark_node for void return types. But allow
310 N_Identifier since we use it for lots of things, including
311 getting trees for discriminants. */
317 {
322 else
325 }
328 {
329 /********************************/
330 /* Chapter 2: Lexical Elements: */
331 /********************************/
338 /* If the Etype of this node does not equal the Etype of the
339 Entity, something is wrong with the entity map, probably in
340 generic instantiation. However, this does not apply to
341 types. Since we sometime have strange Ekind's, just do
342 this test for objects. Also, if the Etype of the Entity
343 is private, the Etype of the N_Identifier is allowed to be the
344 full type and also we consider a packed array type to be the
345 same as the original type. Finally, if the types are Itypes,
346 one may be a copy of the other, which is also legal. */
369 /* If this is a reference to a deferred constant whose partial view
370 is an unconstrained private type, the proper type is on the full
371 view of the constant, not on the full view of the type, which may
372 be unconstrained.
374 This may be a reference to a type, for example in the prefix of the
375 attribute Position, generated for dispatching code (see Make_DT in
376 exp_disp,adb). In that case we need the type itself, not is parent,
377 in particular if it is a derived type */
383 {
387 }
388 else
389 {
390 /* Expand the type of this identitier first, in case it is
391 an enumeral literal, which only get made when the type
392 is expanded. There is no order-of-elaboration issue here.
393 We want to use the Actual_Subtype if it has already been
394 elaborated, otherwise the Etype. Avoid using Actual_Subtype
395 for packed arrays to simplify things. */
403 else
407 }
411 /* If we are in an exception handler, force this variable into memory
412 to ensure optimization does not remove stores that appear
413 redundant but are actually needed in case an exception occurs.
415 ??? Note that we need not do this if the variable is declared within
416 the handler, only if it is referenced in the handler and declared
417 in an enclosing block, but we have no way of testing that
418 right now. */
420 {
423 }
425 /* Some objects (such as parameters passed by reference, globals of
426 variable size, and renamed objects) actually represent the address
427 of the object. In that case, we must do the dereference. Likewise,
428 deal with parameters to foreign convention subprograms. Call fold
429 here since GNU_RESULT may be a CONST_DECL. */
433 {
438 gnu_result);
443 }
445 /* The GNAT tree has the type of a function as the type of its result.
446 Also use the type of the result if the Etype is a subtype which
447 is nominally unconstrained. But remove any padding from the
448 resulting type. */
451 {
456 }
458 /* We always want to return the underlying INTEGER_CST for an
459 enumeration literal to avoid the need to call fold in lots
460 of places. But don't do this is the parent will be taking
461 the address of this object. */
463 {
477 }
481 {
482 tree gnu_type;
484 /* Get the type of the result, looking inside any padding and
485 left-justified modular types. Then get the value in that type. */
494 /* If the result overflows (meaning it doesn't fit in its base type),
495 abort. We would like to check that the value is within the range
496 of the subtype, but that causes problems with subtypes whose usage
497 will raise Constraint_Error and with biased representation, so
498 we don't. */
501 }
505 /* If a Entity is present, it means that this was one of the
506 literals in a user-defined character type. In that case,
507 just return the value in the CONST_DECL. Otherwise, use the
508 character code. In that case, the base type should be an
509 INTEGER_TYPE, but we won't bother checking for that. */
513 else
519 /* If this is of a fixed-point type, the value we want is the
520 value of the corresponding integer. */
522 {
525 gnu_result_type);
527 #if 0
533 gnu_result))
534 #endif
535 )
537 }
538 /* We should never see a Vax_Float type literal, since the front end
539 is supposed to transform these using appropriate conversions */
543 else
544 {
549 /* If the real value is zero, so is the result. Otherwise,
550 convert it to a machine number if it isn't already. That
551 forces BASE to 0 or 2 and simplifies the rest of our logic. */
554 else
555 {
557 ur_realval
561 gnu_result
564 /* If we have a base of zero, divide by the denominator.
565 Otherwise, the base must be 2 and we scale the value, which
566 we know can fit in the mantissa of the type (hence the use
567 of that type above). */
569 gnu_result
572 gnu_result,
574 gnu_result_type));
578 else
579 gnu_result
581 REAL_VALUE_LDEXP
584 }
586 /* Now see if we need to negate the result. Do it this way to
587 properly handle -0. */
589 gnu_result
591 gnu_result);
592 }
599 {
600 /* We assume here that all strings are of type standard.string.
601 "Weird" types of string have been converted to an aggregate
602 by the expander. */
608 /* Build the string with the characters in the literal. Note
609 that Ada strings are 1-origin. */
613 /* Put a null at the end of the string in case it's in a context
614 where GCC will want to treat it as a C string. */
619 /* Strings in GCC don't normally have types, but we want
620 this to not be converted to the array type. */
622 }
623 else
624 {
625 /* Build a list consisting of each character, then make
626 the aggregate. */
633 gnu_list
639 gnu_list);
641 gnu_result
643 }
650 /* Check for (and ignore) unrecognized pragma */
655 {
657 /* Do nothing at top level: all such variables are already
658 viewable. */
666 {
674 }
680 {
694 }
701 }
704 /**************************************/
705 /* Chapter 3: Declarations and Types: */
706 /**************************************/
721 /* If we are just annotating types and this object has an unconstrained
722 or task type, don't elaborate it. */
733 && (! type_annotate_only
735 {
740 /* If this object has its elaboration delayed, we must force
741 evaluation of GNU_EXPR right now and save it for when the object
742 is frozen. */
744 {
747 gnu_expr
751 else
755 }
756 }
757 else
772 /* Don't do anything if this renaming is handled by the front end.
773 or if we are just annotating types and this object has a
774 composite or task type, don't elaborate it. */
776 && ! (type_annotate_only
780 {
783 }
794 /* These are fully handled in the front end. */
797 /*************************************/
798 /* Chapter 4: Names and Expressions: */
799 /*************************************/
805 /* Emit access check if necessary */
813 {
815 tree gnu_type;
820 /* Emit access check if necessary */
827 /* If we got a padded type, remove it too. */
830 gnu_array_object
832 gnu_array_object);
836 /* First compute the number of dimensions of the array, then
837 fill the expression array, the order depending on whether
838 this is a Convention_Fortran array or not. */
843 ;
852 else
860 {
868 gnu_expr
869 = emit_index_check
876 }
877 }
883 {
884 tree gnu_type;
890 /* Emit access check if necessary */
894 /* Do any implicit dereferences of the prefix and do any needed
895 range check. */
900 {
901 /* Get the bounds of the slice. */
902 tree gnu_index_type
908 /* Check to see that the minimum slice value is in range */
909 gnu_expr_l
910 = emit_index_check
915 /* Check to see that the maximum slice value is in range */
916 gnu_expr_h
917 = emit_index_check
922 /* Derive a good type to convert everything too */
925 /* Build a compound expression that does the range checks */
926 gnu_expr
931 /* Build a conditional expression that returns the range checks
932 expression if the slice range is not null (max >= min) or
933 returns the min if the slice range is null */
934 gnu_expr
938 gnu_max_expr),
940 gnu_min_expr)),
942 }
943 else
948 }
952 {
956 tree gnu_field;
960 {
965 }
972 /* For discriminant references in tagged types always substitute the
973 corresponding discriminant as the actual selected component. */
979 /* For discriminant references of untagged types always substitute the
980 corresponding girder discriminant. */
985 /* Handle extracting the real or imaginary part of a complex.
986 The real part is the first field and the imaginary the last. */
992 else
993 {
996 /* If there are discriminants, the prefix might be
997 evaluated more than once, which is a problem if it has
998 side-effects. */
1005 /* Emit discriminant check if necessary. */
1008 gnu_result
1010 }
1016 }
1020 {
1021 /* The attribute designator (like an enumeration value). */
1024 tree gnu_prefix;
1025 tree gnu_type;
1027 /* The Elab_Spec and Elab_Body attributes are special in that
1028 Prefix is a unit, not an object with a GCC equivalent. Similarly
1029 for Elaborated, since that variable isn't otherwise known. */
1031 {
1032 gnu_prefix
1033 = create_subprog_decl
1035 attribute == Attr_Elab_Body
1039 }
1044 /* If the input is a NULL_EXPR, make a new one. */
1046 {
1051 }
1054 {
1057 /* These are just conversions until since representation
1058 clauses for enumerations are handled in the front end. */
1059 {
1066 }
1071 /* These just add or subject the constant 1. Representation
1072 clauses for enumerations are handled in the front-end. */
1077 {
1079 gnu_expr
1080 = emit_check
1082 gnu_expr,
1083 attribute == Attr_Pred
1087 }
1089 gnu_result
1099 /* Conversions don't change something's address but can cause
1100 us to miss the COMPONENT_REF case below, so strip them off. */
1101 gnu_prefix
1105 /* If we are taking 'Address of an unconstrained object,
1106 this is the pointer to the underlying array. */
1109 /* ... fall through ... */
1116 gnu_result
1123 /* For 'Code_Address, find an inner ADDR_EXPR and mark it
1124 so that we don't try to build a trampoline. */
1126 {
1132 ;
1136 }
1147 /* Remove NOPS from gnu_expr and conversions from gnu_prefix.
1148 We only use GNU_EXPR to see if a COMPONENT_REF was involved. */
1156 /* Replace an unconstrained array type with the type of the
1157 underlying array. We can't do this with a call to
1158 maybe_unconstrained_array since we may have a TYPE_DECL.
1159 For 'Max_Size_In_Storage_Elements, use the record type
1160 that will be used to allocate the object and its template. */
1163 {
1167 }
1169 /* If we are looking for the size of a field, return the
1170 field size. Otherwise, if the prefix is an object,
1171 or if 'Object_Size or 'Max_Size_In_Storage_Elements has
1172 been specified, the result is the GCC size of the type.
1173 Otherwise, the result is the RM_Size of the type. */
1179 {
1180 /* If this is a padded type, the GCC size isn't relevant
1181 to the programmer. Normally, what we want is the RM_Size,
1182 which was set from the specified size, but if it was not
1183 set, we want the size of the relevant field. Using the MAX
1184 of those two produces the right result in all case. Don't
1185 use the size of the field if it's a self-referential type,
1186 since that's never what's wanted. */
1190 {
1194 gnu_result
1197 }
1198 else
1200 }
1201 else
1207 /* Deal with a self-referential size by returning the maximum
1208 size for a type and by qualifying the size with
1209 the object for 'Size of an object. */
1213 {
1217 else
1219 }
1221 /* If the type contains a template, subtract the size of the
1222 template. */
1228 /* If the type contains a template, subtract the size of the
1229 template. */
1237 /* Always perform division using unsigned arithmetic as the
1238 size cannot be negative, but may be an overflowed positive
1239 value. This provides correct results for sizes up to 512 MB.
1240 ??? Size should be calculated in storage elements directly. */
1245 gnu_result,
1246 bitsize_unit_node)));
1253 && (TYPE_IS_PADDING_P
1262 gnu_result
1264 else
1275 {
1282 else
1283 gnu_result
1284 = build_binary_op
1286 build_binary_op
1298 }
1299 /* ... fall through ... */
1301 {
1302 int Dimension
1307 /* Emit access check if necessary */
1311 /* Make sure any implicit dereference gets done. */
1319 {
1321 tree gnu_type_temp;
1327 ;
1330 }
1339 gnu_result
1342 gnu_result
1344 else
1345 /* 'Length or 'Range_Length. */
1346 {
1347 tree gnu_compute_type
1348 = gnat_signed_or_unsigned_type
1351 gnu_result
1352 = build_binary_op
1354 build_binary_op
1356 build_binary_op
1359 TYPE_MAX_VALUE
1362 TYPE_MIN_VALUE
1366 }
1368 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
1369 we are handling. Note that these attributes could not
1370 have been used on an unconstrained array type. */
1377 }
1384 {
1385 HOST_WIDE_INT bitsize;
1386 HOST_WIDE_INT bitpos;
1387 tree gnu_offset;
1388 tree gnu_field_bitpos;
1389 tree gnu_field_offset;
1390 tree gnu_inner;
1398 /* We can have 'Bit on any object, but if it isn't a
1399 COMPONENT_REF, the result is zero. Do not allow
1400 'Bit on a bare component, though. */
1404 {
1407 }
1418 {
1419 gnu_field_bitpos
1421 gnu_field_offset
1428 {
1429 gnu_field_bitpos
1433 gnu_field_offset
1437 }
1438 }
1440 {
1443 }
1444 else
1445 {
1448 }
1451 {
1463 gnu_result
1467 bitsize_one_node);
1473 }
1475 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
1476 we are handling. */
1483 }
1506 && (TYPE_IS_PADDING_P
1514 gnu_type
1524 /* Note this size cannot be self-referential. */
1531 /* This is just a zero cast to the pointer type for
1532 our prefix and dereferenced. */
1534 gnu_result
1537 integer_zero_node));
1542 {
1549 {
1554 ;
1555 }
1561 || (DECL_BY_COMPONENT_PTR_P
1565 }
1569 /* Say we have an unimplemented attribute. Then set the
1570 value to be returned to be a zero and hope that's something
1571 we can convert to the type of this attribute. */
1577 }
1579 /* If this is an attribute where the prefix was unused,
1580 force a use of it if it has a side-effect. But don't do it if
1581 the prefix is just an entity name. However, if an access check
1582 is needed, we must do it. See second example in AARM 11.6(5.e). */
1588 }
1592 /* Like 'Access as far as we are concerned. */
1600 {
1601 tree gnu_aggr_type;
1603 /* ??? It is wrong to evaluate the type now, but there doesn't
1604 seem to be any other practical way of doing it. */
1606 gnu_aggr_type = gnu_result_type
1611 gnu_aggr_type
1618 gnu_result
1620 gnu_aggr_type);
1622 {
1623 /* The first element is the discrimant, which we ignore. The
1624 next is the field we're building. Convert the expression
1625 to the type of the field and then to the union type. */
1626 Node_Id gnat_assoc
1629 tree gnu_field_type
1634 }
1637 gnu_aggr_type,
1640 gnu_result
1641 = build_binary_op
1646 (Next
1648 else
1652 }
1662 /* Get the operand expression. */
1666 gnu_result
1678 /* If the result is a pointer type, see if we are improperly
1679 converting to a stricter alignment. */
1683 {
1686 unsigned int oalign
1691 post_error_ne_tree_2
1695 }
1702 {
1705 tree gnu_low;
1706 tree gnu_high;
1708 /* GNAT_RANGE is either an N_Range node or an identifier
1709 denoting a subtype. */
1711 {
1714 }
1717 {
1722 }
1723 else
1728 /* If LOW and HIGH are identical, perform an equality test.
1729 Otherwise, ensure that GNU_OBJECT is only evaluated once
1730 and perform a full range test. */
1734 else
1735 {
1737 gnu_result
1743 }
1747 }
1755 ? RDIV_EXPR
1762 {
1764 tree gnu_rhs_side;
1766 /* The elaboration of the RHS may generate code. If so,
1767 we need to make sure it gets executed after the LHS. */
1777 gnu_rhs);
1780 }
1784 /* These can either be operations on booleans or on modular types.
1785 Fall through for boolean types since that's the way GNU_CODES is
1786 set up. */
1788 Modular_Integer_Kind))
1789 {
1790 enum tree_code code
1801 }
1803 /* ... fall through ... */
1814 {
1816 tree gnu_type;
1822 /* If this is a comparison operator, convert any references to
1823 an unconstrained array value into a reference to the
1824 actual array. */
1826 {
1829 }
1831 /* If the result type is a private type, its full view may be a
1832 numeric subtype. The representation we need is that of its base
1833 type, given that it is the result of an arithmetic operation. */
1835 gnu_type = gnu_result_type
1838 /* If this is a shift whose count is not guaranteed to be correct,
1839 we need to adjust the shift count. */
1842 {
1844 tree gnu_max_shift
1852 gnu_rhs
1853 = build_binary_op
1856 gnu_count_type,
1857 gnu_max_shift,
1859 integer_one_node)),
1860 gnu_rhs);
1861 }
1863 /* For right shifts, the type says what kind of shift to do,
1864 so we may need to choose a different type. */
1873 {
1876 }
1880 /* If this is a logical shift with the shift count not verified,
1881 we must return zero if it is too large. We cannot compensate
1882 above in this case. */
1886 gnu_result
1887 = build_cond_expr
1890 gnu_rhs,
1894 gnu_result);
1895 }
1899 {
1902 tree gnu_false
1909 }
1918 /* This case can apply to a boolean or a modular type.
1919 Fall through for a boolean operand since GNU_CODES is set
1920 up to handle this. */
1922 {
1926 gnu_expr);
1928 }
1930 /* ... fall through ... */
1937 else
1946 {
1948 tree gnu_type;
1952 /* The Expression operand can either be an N_Identifier or
1953 Expanded_Name, which must represent a type, or a
1954 N_Qualified_Expression, which contains both the object type and an
1955 initial value for the object. */
1960 {
1961 Entity_Id gnat_desig_type
1972 {
1975 }
1976 else
1977 {
1983 }
1984 }
1985 else
1992 }
1995 /***************************/
1996 /* Chapter 5: Statements: */
1997 /***************************/
2001 {
2007 /* If this is the first label of an exception handler, we must
2008 mark that any CALL_INSN can jump to it. */
2012 nonlocal_goto_handler_labels
2014 nonlocal_goto_handler_labels);
2015 }
2025 /* Get the LHS and RHS of the statement and convert any reference to an
2026 unconstrained array into a reference to the underlying array. */
2028 gnu_rhs
2033 /* If range check is needed, emit code to generate it */
2037 /* If either side's type has a size that overflows, convert this
2038 into raise of Storage_Error: execution shouldn't have gotten
2039 here anyway. */
2045 else
2051 /* Start an IF statement giving the condition. */
2056 /* Generate code for the statements to be executed if the condition
2057 is true. */
2064 /* Generate each of the "else if" parts. */
2066 {
2070 {
2071 Node_Id gnat_statement;
2075 /* Set up the line numbers for each condition we test. */
2083 }
2084 }
2086 /* Finally, handle any statements in the "else" part. */
2088 {
2095 }
2101 {
2102 Node_Id gnat_when;
2103 Node_Id gnat_choice;
2104 tree gnu_label;
2105 Node_Id gnat_statement;
2116 {
2117 /* First compile all the different case choices for the current
2118 WHEN alternative. */
2122 {
2129 {
2131 /* Abort on all errors except range empty, which
2132 means we ignore this alternative. */
2133 error_code
2143 error_code
2144 = pushcase_range
2157 /* This represents either a subtype range or a static value
2158 of some kind; Ekind says which. If a static value,
2159 fall through to the next case. */
2161 {
2164 error_code
2172 }
2173 /* ... fall through ... */
2188 }
2189 }
2191 /* After compiling the choices attached to the WHEN compile the
2192 body of statements that have to be executed, should the
2193 "WHEN ... =>" be taken. Push a binding level here in case
2194 variables are declared since we want them to be local to this
2195 set of statements instead of the block containing the Case
2196 statement. */
2204 /* Communicate to GCC that we are done with the current WHEN,
2205 i.e. insert a "break" statement. */
2209 }
2212 }
2216 {
2217 /* The loop variable in GCC form, if any. */
2219 /* PREINCREMENT_EXPR or PREDECREMENT_EXPR. */
2221 /* Used if this is a named loop for so EXIT can work. */
2223 /* Condition to continue loop tested at top of loop. */
2225 /* Similar, but tested at bottom of loop. */
2227 Node_Id gnat_statement;
2232 /* Set the condition that under which the loop should continue.
2233 For "LOOP .... END LOOP;" the condition is always true. */
2235 ;
2236 /* The case "WHILE condition LOOP ..... END LOOP;" */
2239 else
2240 {
2241 /* We have an iteration scheme. */
2242 Node_Id gnat_loop_spec
2254 tree gnu_limit
2258 /* We know the loop variable will not overflow if GNU_LAST is
2259 a constant and is not equal to GNU_LIMIT. If it might
2260 overflow, we have to move the limit test to the end of
2261 the loop. In that case, we have to test for an
2262 empty loop outside the loop. */
2266 {
2272 }
2274 /* Open a new nesting level that will surround the loop to declare
2275 the loop index variable. */
2279 /* Declare the loop index and set it to its initial value. */
2283 gnu_loop_var);
2285 /* The loop variable might be a padded type, so use `convert' to
2286 get a reference to the inner variable if so. */
2289 /* Set either the top or bottom exit condition as
2290 appropriate depending on whether we know an overflow
2291 cannot occur or not. */
2293 gnu_bottom_condition
2296 else
2297 gnu_top_condition
2302 }
2307 else
2310 /* If the loop was named, have the name point to this loop. In this
2311 case, the association is not a ..._DECL node; in fact, it isn't
2312 a GCC tree node at all. Since this name is referenced inside
2313 the loop, do it before we process the statements of the loop. */
2315 {
2320 }
2324 /* We must evaluate the condition after we've entered the
2325 loop so that any expression actions get done in the right
2326 place. */
2332 /* Make the loop body into its own block, so any allocated
2333 storage will be released every iteration. This is needed
2334 for stack allocation. */
2337 gnu_block_stack
2354 {
2357 gnu_loop_var,
2359 integer_one_node));
2362 }
2368 {
2369 /* Close the nesting level that sourround the loop that was used to
2370 declare the loop index variable. */
2374 }
2377 {
2380 }
2381 }
2398 {
2399 /* Which loop to exit, NULL if the current loop. */
2401 /* The GCC version of the optional GNAT condition node attached to the
2402 exit statement. Exit the loop if this is false. */
2406 loop_id
2415 }
2422 {
2423 /* The gnu function type of the subprogram currently processed. */
2425 /* The return value from the subprogram. */
2428 /* If we are dealing with a "return;" from an Ada procedure with
2429 parameters passed by copy in copy out, we need to return a record
2430 containing the final values of these parameters. If the list
2431 contains only one entry, return just that entry.
2433 For a full description of the copy in copy out parameter mechanism,
2434 see the part of the gnat_to_gnu_entity routine dealing with the
2435 translation of subprograms.
2437 But if we have a return label defined, convert this into
2438 a branch to that label. */
2444 {
2447 else
2448 gnu_ret_val
2451 }
2453 /* If the Ada subprogram is a function, we just need to return the
2454 expression. If the subprogram returns an unconstrained
2455 array, we have to allocate a new version of the result and
2456 return it. If we return by reference, return a pointer. */
2459 {
2462 /* Do not remove the padding from GNU_RET_VAL if the inner
2463 type is self-referential since we want to allocate the fixed
2464 size in that case. */
2466 && (TYPE_IS_PADDING_P
2468 && contains_placeholder_p
2477 {
2480 /* We have two cases: either the function returns with
2481 depressed stack or not. If not, we allocate on the
2482 secondary stack. If so, we allocate in the stack frame.
2483 if no copy is needed, the front end will set By_Ref,
2484 which we handle in the case above. */
2486 gnu_ret_val
2489 else
2490 gnu_ret_val
2495 }
2496 }
2502 gnu_ret_val));
2503 else
2506 }
2519 /****************************/
2520 /* Chapter 6: Subprograms: */
2521 /****************************/
2524 /* Unless there is a freeze node, declare the subprogram. We consider
2525 this a "definition" even though we're not generating code for
2526 the subprogram because we will be making the corresponding GCC
2527 node here. */
2536 /* This subprogram doesn't exist for code generation purposes, but we
2537 have to elaborate the types of any parameters, unless they are
2538 imported types (nothing to generate in this case). */
2550 /* For a child unit identifier go up a level to get the
2551 specificaton. We get this when we try to find the spec of
2552 a child unit package that is the compilation unit being compiled. */
2557 {
2558 /* Save debug output mode in case it is reset. */
2561 /* Definining identifier of a parameter to the subprogram. */
2562 Entity_Id gnat_param;
2563 /* The defining identifier for the subprogram body. Note that if a
2564 specification has appeared before for this body, then the identifier
2565 occurring in that specification will also be a defining identifier
2566 and all the calls to this subprogram will point to that
2567 specification. */
2568 Entity_Id gnat_subprog_id
2572 /* The FUNCTION_DECL node corresponding to the subprogram spec. */
2573 tree gnu_subprog_decl;
2574 /* The FUNCTION_TYPE node corresponding to the subprogram spec. */
2575 tree gnu_subprog_type;
2576 tree gnu_cico_list;
2578 /* If this is a generic object or if it has been eliminated,
2579 ignore it. */
2586 /* If debug information is suppressed for the subprogram,
2587 turn debug mode off for the duration of processing. */
2589 {
2592 }
2594 /* If this subprogram acts as its own spec, define it. Otherwise,
2595 just get the already-elaborated tree node. However, if this
2596 subprogram had its elaboration deferred, we will already have
2597 made a tree node for it. So treat it as not being defined in
2598 that case. Such a subprogram cannot have an address clause or
2599 a freeze node, so this test is safe, though it does disable
2600 some otherwise-useful error checking. */
2601 gnu_subprog_decl
2608 /* Set the line number in the decl to correspond to that of
2609 the body so that the line number notes are written
2610 correctly. */
2624 /* If there are OUT parameters, we need to ensure that the
2625 return statement properly copies them out. We do this by
2626 making a new block and converting any inner return into a goto
2627 to a label at the end of the block. */
2630 {
2631 gnu_return_label_stack
2634 gnu_return_label_stack);
2637 }
2638 else
2639 gnu_return_label_stack
2642 /* See if there are any parameters for which we don't yet have
2643 GCC entities. These must be for OUT parameters for which we
2644 will be making VAR_DECL nodes here. Fill them in to
2645 TYPE_CI_CO_LIST, which must contain the empty entry as well.
2646 We can match up the entries because TYPE_CI_CO_LIST is in the
2647 order of the parameters. */
2654 else
2655 {
2656 /* Skip any entries that have been already filled in; they
2657 must correspond to IN OUT parameters. */
2660 ;
2662 /* Do any needed references for padded types. */
2666 }
2670 /* Generate the code of the subprogram itself. A return statement
2671 will be present and any OUT parameters will be handled there. */
2679 {
2680 tree gnu_retval;
2690 else
2692 gnu_cico_list);
2695 gnu_retval
2698 expand_return
2701 gnu_retval));
2703 }
2707 /* Disconnect the trees for parameters that we made variables for
2708 from the GNAT entities since these will become unusable after
2709 we end the function. */
2720 }
2729 {
2730 /* The GCC node corresponding to the GNAT subprogram name. This can
2731 either be a FUNCTION_DECL node if we are dealing with a standard
2732 subprogram call, or an indirect reference expression (an
2733 INDIRECT_REF node) pointing to a subprogram. */
2735 /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */
2737 tree gnu_subprog_addr
2739 Entity_Id gnat_formal;
2740 Node_Id gnat_actual;
2744 tree gnu_subprog_call;
2747 {
2755 }
2760 /* If we are calling a stubbed function, make this into a
2761 raise of Program_Error. Elaborate all our args first. */
2765 {
2772 {
2774 gnu_result
2777 }
2778 else
2779 expand_expr_stmt
2782 }
2784 /* The only way we can be making a call via an access type is
2785 if Name is an explicit dereference. In that case, get the
2786 list of formal args from the type the access type is pointing
2787 to. Otherwise, get the formals from entity being called. */
2791 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
2793 else
2796 /* Create the list of the actual parameters as GCC expects it, namely
2797 a chain of TREE_LIST nodes in which the TREE_VALUE field of each
2798 node is a parameter-expression and the TREE_PURPOSE field is
2799 null. Skip OUT parameters that are not passed by reference. */
2805 {
2807 Node_Id gnat_name
2812 tree gnu_actual;
2814 /* If it's possible we may need to use this expression twice,
2815 make sure than any side-effects are handled via SAVE_EXPRs.
2816 Likewise if we need to force side-effects before the call.
2817 ??? This is more conservative than we need since we don't
2818 need to do this for pass-by-ref with no conversion.
2819 If we are passing a non-addressable Out or In Out parameter by
2820 reference, pass the address of a copy and set up to copy back
2821 out after the call. */
2824 {
2831 {
2834 /* Remove any unpadding on the actual and make a copy.
2835 But if the actual is a left-justified modular type,
2836 first convert to it. */
2838 && (TYPE_IS_PADDING_P
2842 && (TYPE_LEFT_JUSTIFIED_MODULAR_P
2848 /* Set up to move the copy back to the original. */
2850 gnu_after_list);
2853 }
2854 }
2856 /* If this was a procedure call, we may not have removed any
2857 padding. So do it here for the part we will use as an
2858 input, if any. */
2864 gnu_actual);
2871 /* Do any needed conversions. We need only check for
2872 unchecked conversion since normal conversions will be handled
2873 by just converting to the formal type. */
2875 {
2876 gnu_actual
2878 gnu_actual);
2880 /* One we've done the unchecked conversion, we still
2881 must ensure that the object is in range of the formal's
2882 type. */
2887 }
2888 else
2889 /* We may have suppressed a conversion to the Etype of the
2890 actual since the parent is a procedure call. So add the
2891 conversion here. */
2893 gnu_actual);
2897 /* If we have not saved a GCC object for the formal, it means
2898 it is an OUT parameter not passed by reference. Otherwise,
2899 look at the PARM_DECL to see if it is passed by reference. */
2903 {
2905 {
2908 /* If we have a padded type, be sure we've removed the
2909 padding. */
2912 gnu_actual
2914 gnu_actual);
2915 }
2917 /* The symmetry of the paths to the type of an entity is
2918 broken here since arguments don't know that they will
2919 be passed by ref. */
2922 gnu_actual);
2923 }
2927 {
2934 {
2935 gnu_formal_type
2938 }
2940 /* Take the address of the object and convert to the
2941 proper pointer type. We'd like to actually compute
2942 the address of the beginning of the array using
2943 an ADDR_EXPR of an ARRAY_REF, but there's a possibility
2944 that the ARRAY_REF might return a constant and we'd
2945 be getting the wrong address. Neither approach is
2946 exactly correct, but this is the most likely to work
2947 in all cases. */
2950 gnu_actual));
2951 }
2955 {
2956 /* If arg is 'Null_Parameter, pass zero descriptor. */
2960 gnu_actual
2962 integer_zero_node);
2963 else
2964 gnu_actual
2967 gnat_formal));
2968 }
2969 else
2970 {
2974 gnu_name_list
2982 /* If this is 'Null_Parameter, pass a zero even though we are
2983 dereferencing it. */
2988 BITS_PER_WORD))
2989 gnu_actual
2990 = unchecked_convert
2994 integer_zero_node));
2995 else
2996 gnu_actual
2999 gnu_actual);
3000 }
3002 gnu_actual_list
3005 }
3009 NULL_TREE);
3012 /* If it is a function call, the result is the call expression. */
3014 {
3017 /* If the function returns an unconstrained array or by reference,
3018 we have to de-dereference the pointer. */
3022 gnu_result);
3025 }
3027 /* If this is the case where the GNAT tree contains a procedure call
3028 but the Ada procedure has copy in copy out parameters, the special
3029 parameter passing mechanism must be used. */
3031 {
3032 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
3033 in copy out parameters. */
3038 {
3039 tree gnu_name;
3043 /* If any of the names had side-effects, ensure they are
3044 all evaluated before the call. */
3048 gnu_subprog_call
3051 }
3055 else
3062 /* If we are dealing with a copy in copy out parameter, we must
3063 retrieve its value from the record returned in the function
3064 call. */
3068 || (DECL_BY_COMPONENT_PTR_P
3072 {
3073 /* Get the value to assign to this OUT or IN OUT
3074 parameter. It is either the result of the function if
3075 there is only a single such parameter or the appropriate
3076 field from the record returned. */
3077 tree gnu_result
3079 : build_component_ref
3082 int unchecked_conversion
3084 /* If the actual is a conversion, get the inner expression,
3085 which will be the real destination, and convert the
3086 result to the type of the actual parameter. */
3087 tree gnu_actual
3090 /* If the result is a padded type, remove the padding. */
3093 gnu_result
3096 gnu_result);
3098 /* If the result is a type conversion, do it. */
3100 gnu_result
3101 = convert_with_check
3108 gnu_result
3110 else
3111 {
3121 gnu_result);
3122 }
3129 }
3130 }
3131 else
3132 {
3135 }
3137 /* Handle anything we need to assign back. */
3139 gnu_expr;
3144 }
3147 /*************************/
3148 /* Chapter 7: Packages: */
3149 /*************************/
3163 /* If this is the body of a generic package - do nothing */
3170 {
3174 }
3177 /*********************************/
3178 /* Chapter 8: Visibility Rules: */
3179 /*********************************/
3183 /* Nothing to do here - but these may appear in list of declarations */
3186 /***********************/
3187 /* Chapter 9: Tasks: */
3188 /***********************/
3197 /***********************************************************/
3198 /* Chapter 10: Program Structure and Compilation Issues: */
3199 /***********************************************************/
3203 /* For a body, first process the spec if there is one. */
3212 {
3219 };
3226 /* Process any pragmas following the unit. */
3232 /* Put all the Actions into the elaboration routine if we already had
3233 elaborations. This will happen anyway if they are statements, but we
3234 want to force declarations there too due to order-of-elaboration
3235 issues. Most should have Is_Statically_Allocated set. If we
3236 have had no elaborations, we have no order-of-elaboration issue and
3237 don't want to create elaborations here. */
3241 {
3245 else
3247 }
3249 /* Generate elaboration code for this unit, if necessary, and
3250 say whether we did or not. */
3251 Set_Has_No_Elaboration_Code
3253 build_unit_elab
3265 /* Simply process whatever unit is being inserted. */
3273 /***************************/
3274 /* Chapter 11: Exceptions: */
3275 /***************************/
3279 /* The GCC exception handling mechanism can handle both ZCX and SJLJ
3280 schemes and we have our own SJLJ mechanism. To call the GCC
3281 mechanism, we first call expand_eh_region_start if there is at least
3282 one handler associated with the region. We then generate code for
3283 the region and call expand_start_all_catch to announce that the
3284 associated handlers are going to be generated.
3286 For each handler we call expand_start_catch, generate code for the
3287 handler, and then call expand_end_catch.
3289 After all the handlers, we call expand_end_all_catch.
3291 Here we deal with the region level calls and the
3292 N_Exception_Handler branch deals with the handler level calls
3293 (start_catch/end_catch).
3295 ??? The region level calls down there have been specifically put in
3296 place for a ZCX context and currently the order in which things are
3297 emitted (region/handlers) is different from the SJLJ case. Instead of
3298 putting other calls with different conditions at other places for the
3299 SJLJ case, it seems cleaner to reorder things for the SJLJ case and
3300 generalize the condition to make it not ZCX specific. */
3302 /* Tell the back-end we are starting a new exception region if
3303 necessary. */
3309 /* If there are exception handlers, start a new binding level that
3310 we can exit (since each exception handler will do so). Then
3311 declare a variable to save the old __gnat_jmpbuf value and a
3312 variable for our jmpbuf. Call setjmp and handle each of the
3313 possible exceptions if it returns one. */
3316 {
3320 tree gnu_cleanup_decl;
3326 {
3327 gnu_jmpsave_decl
3329 jmpbuf_ptr_type,
3338 }
3340 /* See if we are to call a function when exiting this block. */
3342 {
3343 gnu_cleanup_call
3346 gnu_cleanup_decl
3352 }
3355 {
3356 /* When we exit this block, restore the saved value. */
3359 gnu_jmpsave_decl));
3361 /* Call setjmp and handle exceptions if it returns one. */
3363 expand_start_cond
3366 gnu_jmpbuf_decl)),
3369 /* Restore our incoming longjmp value before we do anything. */
3371 gnu_jmpsave_decl));
3376 gnu_except_ptr_stack
3378 create_var_decl
3383 gnu_except_ptr_stack);
3385 /* Generate code for each exception handler. The code at
3386 N_Exception_Handler below does the real work. Note that
3387 we ignore the dummy exception handler for the identifier
3388 case, this is used only by the front end */
3396 /* If none of the exception handlers did anything, re-raise
3397 but do not defer abortion. */
3399 expand_expr_stmt
3407 /* End the "if" on setjmp. Note that we have arranged things so
3408 control never returns here. */
3411 /* This is now immediately before the body proper. Set
3412 our jmp_buf as the current buffer. */
3413 expand_expr_stmt
3416 gnu_jmpbuf_decl)));
3417 }
3418 }
3420 /* If there are no exception handlers, we must not have an at end
3421 cleanup identifier, since the cleanup identifier should always
3422 generate a corresponding exception handler, except in the case
3423 of the No_Exception_Handlers restriction, where the front-end
3424 does not generate exception handlers. */
3426 {
3428 {
3430 tree gnu_cleanup_decl;
3432 gnu_cleanup_call
3435 gnu_cleanup_decl
3441 }
3442 else
3444 }
3446 /* Generate code and declarations for the prefix of this block,
3447 if any. */
3452 /* Generate code for each statement in the block. */
3459 /* Tell the back-end we are ending the new exception region and
3460 starting the associated handlers. */
3466 /* For zero-cost exceptions, exit the block and then compile
3467 the handlers. */
3471 {
3477 }
3479 /* We don't support Front_End_ZCX in GNAT 5.0, but we don't want to
3480 crash if -gnatdX is specified. */
3484 {
3489 }
3491 /* Tell the backend when we are done with the handlers. */
3497 /* If we have handlers, close the block we made. */
3499 {
3502 }
3508 {
3509 /* Unless this is "Others" or the special "Non-Ada" exception
3510 for Ada, make an "if" statement to select the proper
3511 exceptions. For "Others", exclude exceptions where
3512 Handled_By_Others is nonzero unless the All_Others flag is set.
3513 For "Non-ada", accept an exception if "Lang" is 'V'. */
3518 {
3519 tree this_choice;
3522 {
3525 else
3526 this_choice
3527 = build_binary_op
3529 convert
3531 build_component_ref
3532 (build_unary_op
3536 integer_zero_node);
3537 }
3541 {
3542 /* ??? Note that we have to use gnat_to_gnu_entity here
3543 since the type of the exception will be wrong in the
3544 VMS case and that's exactly what this test is for. */
3545 gnu_expr
3548 /* If this was a VMS exception, check import_code
3549 against the value of the exception. */
3551 this_choice
3552 = build_binary_op
3554 build_component_ref
3555 (build_unary_op
3559 gnu_expr);
3560 else
3561 this_choice
3562 = build_binary_op
3565 convert
3569 /* If this is the distinguished exception "Non_Ada_Error"
3570 (and we are in VMS mode), also allow a non-Ada
3571 exception (a VMS condition) to match. */
3573 {
3574 tree gnu_comp
3575 = build_component_ref
3576 (build_unary_op
3581 this_choice
3582 = build_binary_op
3584 build_binary_op
3588 this_choice);
3589 }
3590 }
3591 else
3596 }
3601 }
3603 /* Tell the back end that we start an exception handler if necessary. */
3605 {
3606 /* We build a TREE_LIST of nodes representing what exception
3607 types this handler is able to catch, with special cases
3608 for others and all others cases.
3610 Each exception type is actually identified by a pointer to the
3611 exception id, with special value zero for "others" and one for
3612 "all others". Beware that these special values are known and used
3613 by the personality routine to identify the corresponding specific
3614 kinds of handlers.
3616 ??? For initial time frame reasons, the others and all_others
3617 cases have been handled using specific type trees, but this
3618 somehow hides information to the back-end, which expects NULL to
3619 be passed for catch all and end_cleanup to be used for cleanups.
3621 Care should be taken to ensure that the control flow impact of
3622 such clauses is rendered in some way. lang_eh_type_covers is
3623 doing the trick currently.
3625 ??? Should investigate the possible usage of the end_cleanup
3626 interface in this context. */
3633 {
3635 gnu_etype
3640 {
3644 }
3645 else
3648 gnu_etypes_list
3651 /* The GCC interface expects NULL to be passed for catch all
3652 handlers, so the approach below is quite tempting :
3654 if (gnu_etype == integer_zero_node)
3655 gnu_etypes_list = NULL;
3657 It would not work, however, because GCC's notion
3658 of "catch all" is stronger than our notion of "others".
3660 Until we correctly use the cleanup interface as well, the
3661 two lines above will prevent the "all others" handlers from
3662 beeing seen, because nothing can be caught beyond a catch
3663 all from GCC's point of view. */
3664 }
3667 }
3673 /* At the end of the handler, exit the block. We made this block
3674 in N_Handled_Sequence_Of_Statements. */
3677 /* Tell the back end that we're done with the current handler. */
3685 /*******************************/
3686 /* Chapter 12: Generic Units: */
3687 /*******************************/
3697 /* These nodes can appear on a declaration list but there is nothing to
3698 to be done with them. */
3701 /***************************************************/
3702 /* Chapter 13: Representation Clauses and */
3703 /* Implementation-Dependent Features: */
3704 /***************************************************/
3708 /* The only one we need deal with is for 'Address. For the others, SEM
3709 puts the information elsewhere. We need only deal with 'Address
3710 if the object has a Freeze_Node (which it never will currently). */
3715 /* Get the value to use as the address and save it as the
3716 equivalent for GNAT_TEMP. When the object is frozen,
3717 gnat_to_gnu_entity will do the right thing. */
3725 /* We do nothing with these. SEM puts the information elsewhere. */
3730 {
3736 /* First process inputs, then outputs, then clobbers. */
3739 {
3744 gnu_input_list
3747 }
3751 {
3756 gnu_orig_out_list
3758 gnu_output_list
3761 }
3765 gnu_clobber_list
3768 gnu_clobber_list);
3777 /* Copy all the intermediate outputs into the specified outputs. */
3782 {
3783 expand_expr_stmt
3788 }
3789 }
3792 /***************************************************/
3793 /* Added Nodes */
3794 /***************************************************/
3808 {
3810 tree gnu_obj_type;
3811 tree gnu_obj_size;
3814 /* If this is an unconstrained array, we know the object must
3815 have been allocated with the template in front of the object.
3816 So pass the template address, but get the total size. Do this
3817 by converting to a thin pointer. */
3819 gnu_ptr
3821 (TYPE_OBJECT_RECORD_TYPE
3823 gnu_ptr);
3831 {
3834 tree gnu_byte_offset
3841 }
3844 expand_expr_stmt
3848 }
3861 /* If the type is VOID, this is a statement, so we need to
3862 generate the code for the call. Handle a Condition, if there
3863 is one. */
3865 {
3875 }
3876 else
3880 /* Nothing to do, since front end does all validation using the
3881 values that Gigi back-annotates. */
3894 }
3896 /* If the result is a constant that overflows, raise constraint error. */
3899 {
3902 gnu_result
3905 }
3907 /* If our result has side-effects and is of an unconstrained type,
3908 make a SAVE_EXPR so that we can be sure it will only be referenced
3909 once. Note we must do this before any conversions. */
3916 /* Now convert the result to the proper type. If the type is void or if
3917 we have no result, return error_mark_node to show we have no result.
3918 If the type of the result is correct or if we have a label (which doesn't
3919 have any well-defined type), return our result. Also don't do the
3920 conversion if the "desired" type involves a PLACEHOLDER_EXPR in its size
3921 since those are the cases where the front end may have the type wrong due
3922 to "instantiating" the unconstrained record with discriminant values
3923 or if this is a FIELD_DECL. If this is the Name of an assignment
3924 statement or a parameter of a procedure call, return what we have since
3925 the RHS has to be converted to our type there in that case, unless
3926 GNU_RESULT_TYPE has a simpler size. Similarly, if the two types are
3927 record types with the same name, the expression type has integral mode,
3928 and GNU_RESULT_TYPE BLKmode, don't convert. This will be the case when
3929 we are converting from a packable type to its actual type and we need
3930 those conversions to be NOPs in order for assignments into these types to
3931 work properly if the inner object is a bitfield and hence can't have
3932 its address taken. Finally, don't convert integral types that are the
3933 operand of an unchecked conversion since we need to ignore those
3934 conversions (for 'Valid). Otherwise, convert the result to the proper
3935 type. */
3957 && (contains_placeholder_p
3961 {
3962 /* In this case remove padding only if the inner object is of
3963 self-referential size: in that case it must be an object of
3964 unconstrained type with a default discriminant. In other cases,
3965 we want to avoid copying too much data. */
3972 gnu_result);
3973 }
3989 {
3990 /* Remove any padding record, but do nothing more in this case. */
3994 gnu_result);
3995 }
4003 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RESULT. */
4010 }
4011 \f
4012 /* Force references to each of the entities in packages GNAT_NODE with's
4013 so that the debugging information for all of them are identical
4014 in all clients. Operate recursively on anything it with's, but check
4015 that we aren't elaborating something more than once. */
4017 /* The reason for this routine's existence is two-fold.
4018 First, with some debugging formats, notably MDEBUG on SGI
4019 IRIX, the linker will remove duplicate debugging information if two
4020 clients have identical debugguing information. With the normal scheme
4021 of elaboration, this does not usually occur, since entities in with'ed
4022 packages are elaborated on demand, and if clients have different usage
4023 patterns, the normal case, then the order and selection of entities
4024 will differ. In most cases however, it seems that linkers do not know
4025 how to eliminate duplicate debugging information, even if it is
4026 identical, so the use of this routine would increase the total amount
4027 of debugging information in the final executable.
4029 Second, this routine is called in type_annotate mode, to compute DDA
4030 information for types in withed units, for ASIS use */
4032 static void
4034 Node_Id gnat_node;
4035 {
4040 /* Save entities in all context units. A body may have an implicit_with
4041 on its own spec, if the context includes a child unit, so don't save
4042 the spec twice. */
4050 {
4070 }
4074 }
4075 \f
4076 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
4078 static void
4080 Node_Id gnat_node;
4081 {
4083 tree gnu_old;
4084 tree gnu_new;
4085 tree gnu_init
4090 /* If this is a package, need to generate code for the package. */
4092 {
4093 insert_code_for
4097 }
4099 /* Check for old definition after the above call. This Freeze_Node
4100 might be for one its Itypes. */
4101 gnu_old
4104 /* If this entity has an Address representation clause, GNU_OLD is the
4105 address, so discard it here. */
4109 /* Don't do anything for class-wide types they are always
4110 transformed into their root type. */
4116 /* Don't do anything for subprograms that may have been elaborated before
4117 their freeze nodes. This can happen, for example because of an inner call
4118 in an instance body. */
4125 /* If we have a non-dummy type old tree, we have nothing to do. Unless
4126 this is the public view of a private type whose full view was not
4127 delayed, this node was never delayed as it should have been.
4128 Also allow this to happen for concurrent types since we may have
4129 frozen both the Corresponding_Record_Type and this type. */
4133 {
4140 else
4142 }
4144 /* Reset the saved tree, if any, and elaborate the object or type for real.
4145 If there is a full declaration, elaborate it and copy the type to
4146 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
4147 a class wide type or subtype. */
4149 {
4158 }
4162 {
4165 /* The above call may have defined this entity (the simplest example
4166 of this is when we have a private enumeral type since the bounds
4167 will have the public view. */
4173 }
4174 else
4177 /* If we've made any pointers to the old version of this type, we
4178 have to update them. */
4182 }
4183 \f
4184 /* Process the list of inlined subprograms of GNAT_NODE, which is an
4185 N_Compilation_Unit. */
4187 static void
4189 Node_Id gnat_node;
4190 {
4191 Entity_Id gnat_entity;
4192 Node_Id gnat_body;
4194 /* If we can inline, generate RTL for all the inlined subprograms.
4195 Define the entity first so we set DECL_EXTERNAL. */
4200 {
4204 {
4205 /* ??? This really should always be Present. */
4209 gnat_body
4211 }
4214 {
4217 }
4218 }
4219 }
4220 \f
4221 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
4222 We make two passes, one to elaborate anything other than bodies (but
4223 we declare a function if there was no spec). The second pass
4224 elaborates the bodies.
4226 GNAT_END_LIST gives the element in the list past the end. Normally,
4227 this is Empty, but can be First_Real_Statement for a
4228 Handled_Sequence_Of_Statements.
4230 We make a complete pass through both lists if PASS1P is true, then make
4231 the second pass over both lists if PASS2P is true. The lists usually
4232 correspond to the public and private parts of a package. */
4234 static void
4237 Node_Id gnat_end_list;
4239 {
4241 Node_Id gnat_decl;
4251 {
4254 /* For package specs, we recurse inside the declarations,
4255 thus taking the two pass approach inside the boundary. */
4263 /* Similarly for any declarations in the actions of a
4264 freeze node. */
4266 {
4269 }
4271 /* Package bodies with freeze nodes get their elaboration deferred
4272 until the freeze node, but the code must be placed in the right
4273 place, so record the code position now. */
4281 (Corresponding_Spec
4284 record_code_position
4287 /* We defer most subprogram bodies to the second pass.
4288 However, Init_Proc subprograms cannot be defered, but luckily
4289 don't need to be. */
4293 {
4295 {
4301 }
4302 }
4303 /* For bodies and stubs that act as their own specs, the entity
4304 itself must be elaborated in the first pass, because it may
4305 be used in other declarations. */
4307 {
4308 Node_Id gnat_subprog_id =
4315 }
4317 /* Concurrent stubs stand for the corresponding subprogram bodies,
4318 which are deferred like other bodies. */
4321 ;
4323 else
4325 }
4327 /* Here we elaborate everything we deferred above except for package bodies,
4328 which are elaborated at their freeze nodes. Note that we must also
4329 go inside things (package specs and freeze nodes) the first pass did. */
4335 {
4353 }
4354 }
4355 \f
4356 /* Emits an access check. GNU_EXPR is the expression that needs to be
4357 checked against the NULL pointer. */
4359 static tree
4361 tree gnu_expr;
4362 {
4363 tree gnu_check_expr;
4365 /* Checked expressions must be evaluated only once. */
4368 /* Technically, we check a fat pointer against two words of zero. However,
4369 that's wasteful and really doesn't protect against null accesses. It
4370 makes more sense to check oly the array pointer. */
4372 gnu_check_expr
4379 gnu_check_expr,
4381 integer_zero_node)),
4382 gnu_expr,
4383 CE_Access_Check_Failed);
4384 }
4386 /* Emits a discriminant check. GNU_EXPR is the expression to be checked and
4387 GNAT_NODE a N_Selected_Component node. */
4389 static tree
4391 tree gnu_expr;
4392 Node_Id gnat_node;
4393 {
4394 Entity_Id orig_comp
4397 tree gnu_discr_fct;
4398 Entity_Id gnat_discr;
4400 tree gnu_cond;
4401 Entity_Id gnat_pref_type;
4402 tree gnu_pref_type;
4406 else
4407 {
4410 /* For an untagged derived type, use the discriminants of the parent,
4411 which have been renamed in the derivation, possibly by a one-to-many
4412 constraint. */
4417 }
4424 /* Checked expressions must be evaluated only once. */
4427 /* Create the list of the actual parameters as GCC expects it.
4428 This list is the list of the discriminant fields of the
4429 record expression to be discriminant checked. For documentation
4430 on what is the GCC format for this list see under the
4431 N_Function_Call case */
4435 {
4440 }
4442 gnu_pref_type
4447 {
4448 Entity_Id gnat_real_discr
4454 gnu_actual_list
4457 build_component_ref
4460 }
4465 gnu_actual_list,
4466 NULL_TREE);
4469 return
4470 build_unary_op
4475 gnu_expr),
4476 CE_Discriminant_Check_Failed));
4477 }
4478 \f
4479 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
4480 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
4481 which we have to check. */
4483 static tree
4485 tree gnu_expr;
4486 Entity_Id gnat_range_type;
4487 {
4493 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
4494 we can't do anything since we might be truncating the bounds. No
4495 check is needed in this case. */
4501 /* Checked expressions must be evaluated only once. */
4504 /* There's no good type to use here, so we might as well use
4505 integer_type_node. Note that the form of the check is
4506 (not (expr >= lo)) or (not (expr >= hi))
4507 the reason for this slightly convoluted form is that NaN's
4508 are not considered to be in range in the float case. */
4509 return emit_check
4511 invert_truthvalue
4515 invert_truthvalue
4519 gnu_high)))),
4521 }
4522 \f
4523 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
4524 which we are about to index, GNU_EXPR is the index expression to be
4525 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
4526 against which GNU_EXPR has to be checked. Note that for index
4527 checking we cannot use the emit_range_check function (although very
4528 similar code needs to be generated in both cases) since for index
4529 checking the array type against which we are checking the indeces
4530 may be unconstrained and consequently we need to retrieve the
4531 actual index bounds from the array object itself
4532 (GNU_ARRAY_OBJECT). The place where we need to do that is in
4533 subprograms having unconstrained array formal parameters */
4535 static tree
4537 tree gnu_array_object;
4538 tree gnu_expr;
4539 tree gnu_low;
4540 tree gnu_high;
4541 {
4542 tree gnu_expr_check;
4544 /* Checked expressions must be evaluated only once. */
4547 /* Must do this computation in the base type in case the expression's
4548 type is an unsigned subtypes. */
4551 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
4552 the object we are handling. */
4561 /* There's no good type to use here, so we might as well use
4562 integer_type_node. */
4563 return emit_check
4566 gnu_expr_check,
4568 gnu_low)),
4570 gnu_expr_check,
4572 gnu_high))),
4574 }
4575 \f
4576 /* Given GNU_COND which contains the condition corresponding to an access,
4577 discriminant or range check, of value GNU_EXPR, build a COND_EXPR
4578 that returns GNU_EXPR if GNU_COND is false and raises a
4579 CONSTRAINT_ERROR if GNU_COND is true. REASON is the code that says
4580 why the exception was raised. */
4582 static tree
4584 tree gnu_cond;
4585 tree gnu_expr;
4587 {
4588 tree gnu_call;
4589 tree gnu_result;
4593 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
4594 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
4595 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
4596 out. */
4600 gnu_expr));
4602 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
4603 protect it. Otherwise, show GNU_RESULT has no side effects: we
4604 don't need to evaluate it just for the check. */
4606 gnu_result
4608 else
4611 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
4612 we will repeatedly do the test. It would be nice if GCC was able
4613 to optimize this and only do it once. */
4615 }
4616 \f
4617 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
4618 overflow checks if OVERFLOW_P is nonzero and range checks if
4619 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
4620 If TRUNCATE_P is nonzero, do a float to integer conversion with
4621 truncation; otherwise round. */
4623 static tree
4625 Entity_Id gnat_type;
4626 tree gnu_expr;
4630 {
4642 /* If we are not doing any checks, the output is an integral type, and
4643 the input is not a floating type, just do the conversion. This
4644 shortcut is required to avoid problems with packed array types
4645 and simplifies code in all cases anyway. */
4650 /* First convert the expression to its base type. This
4651 will never generate code, but makes the tests below much simpler.
4652 But don't do this if converting from an integer type to an unconstrained
4653 array type since then we need to get the bounds from the original
4654 (unpacked) type. */
4658 /* If overflow checks are requested, we need to be sure the result will
4659 fit in the output base type. But don't do this if the input
4660 is integer and the output floating-point. */
4663 {
4664 /* Ensure GNU_EXPR only gets evaluated once. */
4668 /* Convert the lower bounds to signed types, so we're sure we're
4669 comparing them properly. Likewise, convert the upper bounds
4670 to unsigned types. */
4684 /* Check each bound separately and only if the result bound
4685 is tighter than the bound on the input type. Note that all the
4686 types are base types, so the bounds must be constant. Also,
4687 the comparison is done in the base type of the input, which
4688 always has the proper signedness. First check for input
4689 integer (which means output integer), output float (which means
4690 both float), or mixed, in which case we always compare.
4691 Note that we have to do the comparison which would *fail* in the
4692 case of an error since if it's an FP comparison and one of the
4693 values is a NaN or Inf, the comparison will fail. */
4700 gnu_cond
4701 = invert_truthvalue
4704 gnu_out_lb)));
4712 gnu_cond
4714 invert_truthvalue
4716 gnu_input,
4718 gnu_out_ub))));
4722 CE_Overflow_Check_Failed);
4723 }
4725 /* Now convert to the result base type. If this is a non-truncating
4726 float-to-integer conversion, round. */
4729 {
4739 gnu_result
4741 }
4747 else
4750 /* Finally, do the range check if requested. Note that if the
4751 result type is a modular type, the range check is actually
4752 an overflow check. */
4760 }
4761 \f
4762 /* Return 1 if GNU_EXPR can be directly addressed. This is the case
4763 unless it is an expression involving computation or if it involves
4764 a bitfield reference. This returns the same as
4765 gnat_mark_addressable in most cases. */
4767 static int
4769 tree gnu_expr;
4770 {
4772 {
4797 {
4798 /* This is addressable if we can avoid a copy. */
4812 }
4816 }
4817 }
4818 \f
4819 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
4820 a separate Freeze node exists, delay the bulk of the processing. Otherwise
4821 make a GCC type for GNAT_ENTITY and set up the correspondance. */
4823 void
4825 Entity_Id gnat_entity;
4826 {
4827 tree gnu_old
4829 tree gnu_new;
4831 /* If we are to delay elaboration of this type, just do any
4832 elaborations needed for expressions within the declaration and
4833 make a dummy type entry for this node and its Full_View (if
4834 any) in case something points to it. Don't do this if it
4835 has already been done (the only way that can happen is if
4836 the private completion is also delayed). */
4842 {
4846 {
4855 }
4858 }
4860 /* If we saved away a dummy type for this node it means that this
4861 made the type that corresponds to the full type of an incomplete
4862 type. Clear that type for now and then update the type in the
4863 pointers. */
4865 {
4868 {
4869 /* If this was a withed access type, this is not an error
4870 and merely indicates we've already elaborated the type
4871 already. */
4876 }
4879 }
4881 /* Now fully elaborate the type. */
4886 /* If we have an old type and we've made pointers to this type,
4887 update those pointers. */
4892 /* If this is a record type corresponding to a task or protected type
4893 that is a completion of an incomplete type, perform a similar update
4894 on the type. */
4895 /* ??? Including protected types here is a guess. */
4900 {
4901 tree gnu_task_old
4911 }
4912 }
4913 \f
4914 /* GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate.
4915 GNU_TYPE is the GCC type of the corresponding record.
4917 Return a CONSTRUCTOR to build the record. */
4919 static tree
4921 Node_Id gnat_assoc;
4922 tree gnu_type;
4923 {
4926 /* We test for GNU_FIELD being empty in the case where a variant
4927 was the last thing since we don't take things off GNAT_ASSOC in
4928 that case. We check GNAT_ASSOC in case we have a variant, but it
4929 has no fields. */
4933 {
4938 /* The expander is supposed to put a single component selector name
4939 in every record component association */
4943 /* Before assigning a value in an aggregate make sure range checks
4944 are done if required. Then convert to the type of the field. */
4950 /* Add the field and expression to the list. */
4952 }
4956 /* Verify every enty in GNU_LIST was used. */
4962 }
4964 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
4965 is the first element of an array aggregate. It may itself be an
4966 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
4967 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
4968 of the array component. It is needed for range checking. */
4970 static tree
4972 Node_Id gnat_expr;
4973 tree gnu_array_type;
4974 Entity_Id gnat_component_type;
4975 {
4976 tree gnu_expr;
4980 {
4981 /* If the expression is itself an array aggregate then first build the
4982 innermost constructor if it is part of our array (multi-dimensional
4983 case). */
4990 gnat_component_type);
4991 else
4992 {
4995 /* before assigning the element to the array make sure it is
4996 in range */
4999 }
5001 gnu_expr_list
5003 gnu_expr_list);
5004 }
5007 }
5008 \f
5009 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
5010 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
5011 of the associations that are from RECORD_TYPE. If we see an internal
5012 record, make a recursive call to fill it in as well. */
5014 static tree
5016 tree values;
5017 tree record_type;
5018 {
5023 {
5026 /* _Parent is an internal field, but may have values in the aggregate,
5027 so check for values first. */
5029 {
5032 }
5035 {
5040 }
5041 else
5042 /* If we have a record subtype, the names will match, but not the
5043 actual FIELD_DECLs. */
5046 {
5049 }
5055 }
5058 }
5059 \f
5060 /* EXP is to be treated as an array or record. Handle the cases when it is
5061 an access object and perform the required dereferences. */
5063 static tree
5065 tree exp;
5066 {
5067 /* If the type is a pointer, dereference it. */
5072 /* If we got a padded type, remove it too. */
5078 }
5079 \f
5080 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
5082 tree
5084 tree exp;
5085 {
5088 /* If this has no side effects, we don't need to do anything. */
5092 /* If it is a conversion, protect what's inside the conversion.
5093 Similarly, if we're indirectly referencing something, we only
5094 actually need to protect the address since the data itself can't
5095 change in these situations. */
5104 /* If EXP is a fat pointer or something that can be placed into a register,
5105 just make a SAVE_EXPR. */
5109 /* Otherwise, dereference, protect the address, and re-reference. */
5110 else
5111 return
5115 exp)));
5116 }
5117 \f
5118 /* This is equivalent to stabilize_reference in GCC's tree.c, but we know
5119 how to handle our new nodes and we take an extra argument that says
5120 whether to force evaluation of everything. */
5122 tree
5124 tree ref;
5126 {
5132 {
5136 /* No action is needed in this case. */
5148 result
5157 force));
5163 force),
5171 force),
5173 force));
5180 force));
5187 force));
5193 force),
5195 force));
5204 /* If arg isn't a kind of lvalue we recognize, make no change.
5205 Caller should recognize the error for an invalid lvalue. */
5211 }
5215 }
5217 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
5218 arg to force a SAVE_EXPR for everything. */
5220 static tree
5222 tree e;
5224 {
5229 /* We cannot ignore const expressions because it might be a reference
5230 to a const array but whose index contains side-effects. But we can
5231 ignore things that are actual constant or that already have been
5232 handled by this function. */
5238 {
5252 /* Constants need no processing. In fact, we should never reach
5253 here. */
5257 /* Recursively stabilize each operand. */
5264 /* Recursively stabilize each operand. */
5267 force));
5272 }
5276 }
5277 \f
5278 /* GNAT_UNIT is the Defining_Identifier for some package or subprogram,
5279 either a spec or a body, BODY_P says which. If needed, make a function
5280 to be the elaboration routine for that object and perform the elaborations
5281 in GNU_ELAB_LIST.
5283 Return 1 if we didn't need an elaboration function, zero otherwise. */
5285 static int
5287 Entity_Id gnat_unit;
5289 tree gnu_elab_list;
5290 {
5291 tree gnu_decl;
5292 rtx insn;
5295 /* If we have nothing to do, return. */
5299 /* Set our file and line number to that of the object and set up the
5300 elaboration routine. */
5302 body_p ?
5314 /* Emit the assignments for the elaborations we have to do. If there
5315 is no destination, this is just a call to execute some statement
5316 that was placed within the declarative region. But first save a
5317 pointer so we can see if any insns were generated. */
5323 {
5326 }
5327 else
5328 {
5334 /* If LHS has a padded type, convert it to the unpadded type
5335 so the assignment is done properly. */
5344 }
5346 /* See if any non-NOTE insns were generated. */
5349 {
5352 }
5359 /* If there were no insns, we don't need an elab routine. It would
5360 be nice to not output this one, but there's no good way to do that. */
5362 }
5363 \f
5366 /* Determine the input_filename and the lineno from the source location
5367 (Sloc) of GNAT_NODE node. Set the global variable input_filename and
5368 lineno. If WRITE_NOTE_P is true, emit a line number note. */
5370 void
5372 Node_Id gnat_node;
5374 {
5377 /* If node not from source code, ignore. */
5381 /* Use the identifier table to make a hashed, permanent copy of the filename,
5382 since the name table gets reallocated after Gigi returns but before all
5383 the debugging information is output. The call to
5384 __gnat_to_canonical_file_spec translates filenames from pragmas
5385 Source_Reference that contain host style syntax not understood by gdb. */
5386 input_filename
5387 = IDENTIFIER_POINTER
5388 (get_identifier
5389 (__gnat_to_canonical_file_spec
5390 (Get_Name_String
5393 /* ref_filename is the reference file name as given by sinput (i.e no
5394 directory) */
5395 ref_filename
5396 = IDENTIFIER_POINTER
5397 (get_identifier
5398 (Get_Name_String
5404 }
5405 \f
5406 /* Post an error message. MSG is the error message, properly annotated.
5407 NODE is the node at which to post the error and the node to use for the
5408 "&" substitution. */
5410 void
5413 Node_Id node;
5414 {
5415 String_Template temp;
5416 Fat_Pointer fp;
5422 }
5424 /* Similar, but NODE is the node at which to post the error and ENT
5425 is the node to use for the "&" substitution. */
5427 void
5430 Node_Id node;
5431 Entity_Id ent;
5432 {
5433 String_Template temp;
5434 Fat_Pointer fp;
5440 }
5442 /* Similar, but NODE is the node at which to post the error, ENT is the node
5443 to use for the "&" substitution, and N is the number to use for the ^. */
5445 void
5448 Node_Id node;
5449 Entity_Id ent;
5451 {
5452 String_Template temp;
5453 Fat_Pointer fp;
5461 }
5462 \f
5463 /* Similar to post_error_ne_num, but T is a GCC tree representing the
5464 number to write. If the tree represents a constant that fits within
5465 a host integer, the text inside curly brackets in MSG will be output
5466 (presumably including a '^'). Otherwise that text will not be output
5467 and the text inside square brackets will be output instead. */
5469 void
5472 Node_Id node;
5473 Entity_Id ent;
5474 tree t;
5475 {
5478 Fat_Pointer fp;
5486 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
5488 #endif
5489 )
5490 {
5493 }
5494 else
5498 {
5504 ;
5505 else
5507 }
5514 }
5516 /* Similar to post_error_ne_tree, except that NUM is a second
5517 integer to write in the message. */
5519 void
5522 Node_Id node;
5523 Entity_Id ent;
5524 tree t;
5526 {
5529 }
5531 /* Set the node for a second '&' in the error message. */
5533 void
5535 Entity_Id e;
5536 {
5538 }
5539 \f
5540 /* Signal abort, with "Gigi abort" as the error label, and error_gnat_node
5541 as the relevant node that provides the location info for the error */
5543 void
5546 {
5548 Fat_Pointer fp;
5554 }
5555 \f
5556 /* Initialize the table that maps GNAT codes to GCC codes for simple
5557 binary and unary operations. */
5559 void
5561 {
5587 }