| blob | 961425224e850080c98990a4ec5cb3b55371f762 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * T R A N S *
6 * *
7 * C Implementation File *
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, 51 Franklin Street, Fifth Floor, *
20 * Boston, MA 02110-1301, 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 ****************************************************************************/
71 /* Current filename without path. */
74 /* If true, then gigi is being called on an analyzed but unexpanded
75 tree, and the only purpose of the call is to properly annotate
76 types with representation information. */
79 /* A structure used to gather together information about a statement group.
80 We use this to gather related statements, for example the "then" part
81 of a IF. In the case where it represents a lexical scope, we may also
82 have a BLOCK node corresponding to it and/or cleanups. */
89 };
93 /* List of unused struct stmt_group nodes. */
96 /* A structure used to record information on elaboration procedures
97 we've made and need to process.
99 ??? gnat_node should be Node_Id, but gengtype gets confused. */
105 };
109 /* Free list of TREE_LIST nodes used for stacks. */
112 /* List of TREE_LIST nodes representing a stack of exception pointer
113 variables. TREE_VALUE is the VAR_DECL that stores the address of
114 the raised exception. Nonzero means we are in an exception
115 handler. Not used in the zero-cost case. */
118 /* List of TREE_LIST nodes used to store the current elaboration procedure
119 decl. TREE_VALUE is the decl. */
122 /* Variable that stores a list of labels to be used as a goto target instead of
123 a return in some functions. See processing for N_Subprogram_Body. */
126 /* List of TREE_LIST nodes representing a stack of LOOP_STMT nodes.
127 TREE_VALUE of each entry is the label of the corresponding LOOP_STMT. */
130 /* List of TREE_LIST nodes representing labels for switch statements.
131 TREE_VALUE of each entry is the label at the end of the switch. */
134 /* Map GNAT tree codes to GCC tree codes for simple expressions. */
137 /* Current node being treated, in case abort called. */
138 Node_Id error_gnat_node;
170 \f
171 /* This is the main program of the back-end. It sets up all the table
172 structures and then generates code. */
174 void
182 Int gigi_operating_mode)
183 {
184 tree gnu_standard_long_long_float;
185 tree gnu_standard_exception_type;
205 /* If we are just annotating types, give VOID_TYPE zero sizes to avoid
206 errors. */
208 {
211 }
213 /* Save the type we made for integer as the type for Standard.Integer.
214 Then make the rest of the standard types. Note that some of these
215 may be subtypes. */
221 gnu_standard_long_long_float
223 gnu_standard_exception_type
228 /* Process any Pragma Ident for the main unit. */
229 #ifdef ASM_OUTPUT_IDENT
231 ASM_OUTPUT_IDENT
234 #endif
236 /* If we are using the GCC exception mechanism, let GCC know. */
243 /* Now see if we have any elaboration procedures to deal with. */
245 {
247 tree gnu_stmts;
249 /* Mark everything we have as not visited. */
252 /* Set the current function to be the elaboration procedure and gimplify
253 what we have. */
257 /* We should have a BIND_EXPR, but it may or may not have any statements
258 in it. If it doesn't have any, we have nothing to do. */
263 /* If there are no statements, there is no elaboration code. */
266 else
267 {
268 /* Otherwise, compile the function. Note that we'll be gimplifying
269 it twice, but that's fine for the nodes we use. */
272 }
273 }
274 }
275 \f
276 /* Perform initializations for this module. */
278 void
280 {
281 /* Initialize ourselves. */
285 /* Enable GNAT stack checking method if needed */
290 }
291 \f
292 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier,
293 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
294 where we should place the result type. */
296 static tree
298 {
299 tree gnu_result_type;
300 tree gnu_result;
303 /* If the Etype of this node does not equal the Etype of the Entity,
304 something is wrong with the entity map, probably in generic
305 instantiation. However, this does not apply to types. Since we sometime
306 have strange Ekind's, just do this test for objects. Also, if the Etype of
307 the Entity is private, the Etype of the N_Identifier is allowed to be the
308 full type and also we consider a packed array type to be the same as the
309 original type. Similarly, a class-wide type is equivalent to a subtype of
310 itself. Finally, if the types are Itypes, one may be a copy of the other,
311 which is also legal. */
334 /* If this is a reference to a deferred constant whose partial view is an
335 unconstrained private type, the proper type is on the full view of the
336 constant, not on the full view of the type, which may be unconstrained.
338 This may be a reference to a type, for example in the prefix of the
339 attribute Position, generated for dispatching code (see Make_DT in
340 exp_disp,adb). In that case we need the type itself, not is parent,
341 in particular if it is a derived type */
346 {
350 }
351 else
352 {
353 /* Expand the type of this identifier first, in case it is an enumeral
354 literal, which only get made when the type is expanded. There is no
355 order-of-elaboration issue here. We want to use the Actual_Subtype if
356 it has already been elaborated, otherwise the Etype. Avoid using
357 Actual_Subtype for packed arrays to simplify things. */
365 else
369 }
373 /* If we are in an exception handler, force this variable into memory to
374 ensure optimization does not remove stores that appear redundant but are
375 actually needed in case an exception occurs.
377 ??? Note that we need not do this if the variable is declared within the
378 handler, only if it is referenced in the handler and declared in an
379 enclosing block, but we have no way of testing that right now.
381 ??? Also, for now all we can do is make it volatile. But we only
382 do this for SJLJ. */
387 /* Some objects (such as parameters passed by reference, globals of
388 variable size, and renamed objects) actually represent the address
389 of the object. In that case, we must do the dereference. Likewise,
390 deal with parameters to foreign convention subprograms. Call fold
391 here since GNU_RESULT may be a CONST_DECL. */
396 {
398 tree renamed_obj;
402 gnu_result
405 gnu_result));
407 /* If it's a renaming pointer and we are at the right binding level,
408 we can reference the renamed object directly, since the renamed
409 expression has been protected against multiple evaluations. */
414 /* Make sure it's an lvalue like INDIRECT_REF. */
421 else
426 }
428 /* The GNAT tree has the type of a function as the type of its result. Also
429 use the type of the result if the Etype is a subtype which is nominally
430 unconstrained. But remove any padding from the resulting type. */
433 {
438 }
440 /* We always want to return the underlying INTEGER_CST for an enumeration
441 literal to avoid the need to call fold in lots of places. But don't do
442 this is the parent will be taking the address of this object. */
444 {
458 }
462 }
463 \f
464 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return
465 any statements we generate. */
467 static tree
469 {
470 Node_Id gnat_temp;
473 /* Check for (and ignore) unrecognized pragma and do nothing if we are just
474 annotating types. */
479 {
481 /* Do nothing at top level: all such variables are already viewable. */
488 {
497 }
503 {
516 }
523 }
526 }
527 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Attribute,
528 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
529 where we should place the result type. ATTRIBUTE is the attribute ID. */
531 static tree
533 {
535 tree gnu_result_type;
536 tree gnu_expr;
541 /* If the input is a NULL_EXPR, make a new one. */
543 {
547 }
550 {
553 /* These are just conversions until since representation clauses for
554 enumerations are handled in the front end. */
555 {
562 }
567 /* These just add or subject the constant 1. Representation clauses for
568 enumerations are handled in the front-end. */
573 {
575 gnu_expr
576 = emit_check
578 gnu_expr,
579 attribute == Attr_Pred
583 }
585 gnu_result
594 /* Conversions don't change something's address but can cause us to miss
595 the COMPONENT_REF case below, so strip them off. */
599 /* If we are taking 'Address of an unconstrained object, this is the
600 pointer to the underlying array. */
604 /* ... fall through ... */
610 gnu_result
617 /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we
618 don't try to build a trampoline. */
620 {
629 }
633 {
634 tree gnu_obj_type;
639 /* If this is an unconstrained array, we know the object must have been
640 allocated with the template in front of the object. So compute the
641 template address.*/
643 gnu_ptr
645 (TYPE_OBJECT_RECORD_TYPE
647 gnu_ptr);
652 {
655 tree gnu_byte_offset
662 }
665 }
674 /* Remove NOPS from gnu_expr and conversions from gnu_prefix.
675 We only use GNU_EXPR to see if a COMPONENT_REF was involved. */
678 ;
684 /* Replace an unconstrained array type with the type of the underlying
685 array. We can't do this with a call to maybe_unconstrained_array
686 since we may have a TYPE_DECL. For 'Max_Size_In_Storage_Elements,
687 use the record type that will be used to allocate the object and its
688 template. */
690 {
694 }
696 /* If we're looking for the size of a field, return the field size.
697 Otherwise, if the prefix is an object, or if 'Object_Size or
698 'Max_Size_In_Storage_Elements has been specified, the result is the
699 GCC size of the type. Otherwise, the result is the RM_Size of the
700 type. */
706 {
707 /* If this is a padded type, the GCC size isn't relevant to the
708 programmer. Normally, what we want is the RM_Size, which was set
709 from the specified size, but if it was not set, we want the size
710 of the relevant field. Using the MAX of those two produces the
711 right result in all case. Don't use the size of the field if it's
712 a self-referential type, since that's never what's wanted. */
716 {
720 gnu_result
723 }
724 else
726 }
727 else
732 /* Deal with a self-referential size by returning the maximum size for a
733 type and by qualifying the size with the object for 'Size of an
734 object. */
736 {
739 else
741 }
743 /* If the type contains a template, subtract its size. */
751 /* Always perform division using unsigned arithmetic as the size cannot
752 be negative, but may be an overflowed positive value. This provides
753 correct results for sizes up to 512 MB.
755 ??? Size should be calculated in storage elements directly. */
776 else
786 {
793 else
794 gnu_result
795 = build_binary_op
797 build_binary_op
809 }
811 /* ... fall through ... */
814 {
819 /* Make sure any implicit dereference gets done. */
827 {
829 tree gnu_type_temp;
835 ;
838 }
845 gnu_result
848 gnu_result
850 else
851 /* 'Length or 'Range_Length. */
852 {
853 tree gnu_compute_type
857 gnu_result
858 = build_binary_op
860 build_binary_op
862 build_binary_op
865 TYPE_MAX_VALUE
868 TYPE_MIN_VALUE
872 }
874 /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are
875 handling. Note that these attributes could not have been used on
876 an unconstrained array type. */
878 gnu_prefix);
880 }
887 {
888 HOST_WIDE_INT bitsize;
889 HOST_WIDE_INT bitpos;
890 tree gnu_offset;
891 tree gnu_field_bitpos;
892 tree gnu_field_offset;
893 tree gnu_inner;
901 /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF,
902 the result is 0. Don't allow 'Bit on a bare component, though. */
906 {
909 }
911 else
920 {
928 {
929 gnu_field_bitpos
932 gnu_field_offset
935 }
936 }
938 {
941 }
942 else
943 {
946 }
949 {
964 bitsize_one_node);
970 }
972 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
973 we are handling. */
976 }
980 {
988 }
1016 /* Note this size cannot be self-referential. */
1023 /* This is just a zero cast to the pointer type for
1024 our prefix and dereferenced. */
1026 gnu_result
1029 integer_zero_node));
1034 {
1041 {
1046 ;
1047 }
1055 && (DECL_BY_COMPONENT_PTR_P
1059 }
1063 /* Say we have an unimplemented attribute. Then set the value to be
1064 returned to be a zero and hope that's something we can convert to the
1065 type of this attribute. */
1070 }
1072 /* If this is an attribute where the prefix was unused, force a use of it if
1073 it has a side-effect. But don't do it if the prefix is just an entity
1074 name. However, if an access check is needed, we must do it. See second
1075 example in AARM 11.6(5.e). */
1083 }
1084 \f
1085 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement,
1086 to a GCC tree, which is returned. */
1088 static tree
1090 {
1091 tree gnu_result;
1092 tree gnu_expr;
1093 Node_Id gnat_when;
1098 /* The range of values in a case statement is determined by the rules in
1099 RM 5.4(7-9). In almost all cases, this range is represented by the Etype
1100 of the expression. One exception arises in the case of a simple name that
1101 is parenthesized. This still has the Etype of the name, but since it is
1102 not a name, para 7 does not apply, and we need to go to the base type.
1103 This is the only case where parenthesization affects the dynamic
1104 semantics (i.e. the range of possible values at runtime that is covered
1105 by the others alternative.
1107 Another exception is if the subtype of the expression is non-static. In
1108 that case, we also have to use the base type. */
1114 /* We build a SWITCH_EXPR that contains the code with interspersed
1115 CASE_LABEL_EXPRs for each label. */
1122 {
1123 Node_Id gnat_choice;
1125 /* First compile all the different case choices for the current WHEN
1126 alternative. */
1129 {
1133 {
1148 /* This represents either a subtype range or a static value of
1149 some kind; Ekind says which. If a static value, fall through
1150 to the next case. */
1152 {
1158 }
1160 /* ... fall through ... */
1172 }
1177 gnat_choice);
1178 }
1180 /* Push a binding level here in case variables are declared since we want
1181 them to be local to this set of statements instead of the block
1182 containing the Case statement. */
1186 }
1188 /* Now emit a definition of the label all the cases branched to. */
1196 }
1197 \f
1198 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement,
1199 to a GCC tree, which is returned. */
1201 static tree
1203 {
1204 /* ??? It would be nice to use "build" here, but there's no build5. */
1210 tree gnu_result;
1217 /* Save the end label of this LOOP_STMT in a stack so that the corresponding
1218 N_Exit_Statement can find it. */
1222 /* Set the condition that under which the loop should continue.
1223 For "LOOP .... END LOOP;" the condition is always true. */
1225 ;
1226 /* The case "WHILE condition LOOP ..... END LOOP;" */
1230 else
1231 {
1232 /* We have an iteration scheme. */
1247 /* We know the loop variable will not overflow if GNU_LAST is a constant
1248 and is not equal to GNU_LIMIT. If it might overflow, we have to move
1249 the limit test to the end of the loop. In that case, we have to test
1250 for an empty loop outside the loop. */
1254 {
1255 gnu_cond_expr
1261 }
1263 /* Open a new nesting level that will surround the loop to declare the
1264 loop index variable. */
1268 /* Declare the loop index and set it to its initial value. */
1273 /* The loop variable might be a padded type, so use `convert' to get a
1274 reference to the inner variable if so. */
1277 /* Set either the top or bottom exit condition as appropriate depending
1278 on whether or not we know an overflow cannot occur. */
1283 else
1292 gnu_loop_var,
1294 integer_one_node));
1296 gnat_iter_scheme);
1297 }
1299 /* If the loop was named, have the name point to this loop. In this case,
1300 the association is not a ..._DECL node, but the end label from this
1301 LOOP_STMT. */
1306 /* Make the loop body into its own block, so any allocated storage will be
1307 released every iteration. This is needed for stack allocation. */
1311 /* If we declared a variable, then we are in a statement group for that
1312 declaration. Add the LOOP_STMT to it and make that the "loop". */
1314 {
1318 }
1320 /* If we have an outer COND_EXPR, that's our result and this loop is its
1321 "true" statement. Otherwise, the result is the LOOP_STMT. */
1323 {
1327 }
1328 else
1334 }
1335 \f
1336 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We
1337 don't return anything. */
1339 static void
1341 {
1342 /* Save debug output mode in case it is reset. */
1345 /* Defining identifier of a parameter to the subprogram. */
1346 Entity_Id gnat_param;
1347 /* The defining identifier for the subprogram body. Note that if a
1348 specification has appeared before for this body, then the identifier
1349 occurring in that specification will also be a defining identifier and all
1350 the calls to this subprogram will point to that specification. */
1351 Entity_Id gnat_subprog_id
1354 /* The FUNCTION_DECL node corresponding to the subprogram spec. */
1355 tree gnu_subprog_decl;
1356 /* The FUNCTION_TYPE node corresponding to the subprogram spec. */
1357 tree gnu_subprog_type;
1358 tree gnu_cico_list;
1359 tree gnu_result;
1361 /* If this is a generic object or if it has been eliminated,
1362 ignore it. */
1368 /* If debug information is suppressed for the subprogram, turn debug
1369 mode off for the duration of processing. */
1371 {
1374 }
1376 /* If this subprogram acts as its own spec, define it. Otherwise, just get
1377 the already-elaborated tree node. However, if this subprogram had its
1378 elaboration deferred, we will already have made a tree node for it. So
1379 treat it as not being defined in that case. Such a subprogram cannot
1380 have an address clause or a freeze node, so this test is safe, though it
1381 does disable some otherwise-useful error checking. */
1382 gnu_subprog_decl
1389 /* Set the line number in the decl to correspond to that of the body so that
1390 the line number notes are written
1391 correctly. */
1397 /* If there are OUT parameters, we need to ensure that the return statement
1398 properly copies them out. We do this by making a new block and converting
1399 any inner return into a goto to a label at the end of the block. */
1403 /* Get a tree corresponding to the code for the subprogram. */
1407 /* See if there are any parameters for which we don't yet have GCC entities.
1408 These must be for OUT parameters for which we will be making VAR_DECL
1409 nodes here. Fill them in to TYPE_CI_CO_LIST, which must contain the empty
1410 entry as well. We can match up the entries because TYPE_CI_CO_LIST is in
1411 the order of the parameters. */
1416 {
1417 /* Skip any entries that have been already filled in; they must
1418 correspond to IN OUT parameters. */
1421 ;
1423 /* Do any needed references for padded types. */
1427 }
1431 /* Generate the code of the subprogram itself. A return statement will be
1432 present and any OUT parameters will be handled there. */
1437 /* If we made a special return label, we need to make a block that contains
1438 the definition of that label and the copying to the return value. That
1439 block first contains the function, then the label and copy statement. */
1441 {
1442 tree gnu_retval;
1453 else
1455 gnu_cico_list);
1460 add_stmt_with_node
1464 gnat_node);
1467 }
1471 /* Initialize the information node for the function and set the
1472 end location. */
1474 Sloc_to_locus
1482 /* Disconnect the trees for parameters that we made variables for from the
1483 GNAT entities since these are unusable after we end the function. */
1493 }
1494 \f
1495 /* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call
1496 or an N_Procedure_Call_Statement, to a GCC tree, which is returned.
1497 GNU_RESULT_TYPE_P is a pointer to where we should place the result type.
1498 If GNU_TARGET is non-null, this must be a function call and the result
1499 of the call is to be placed into that object. */
1501 static tree
1503 {
1504 tree gnu_result;
1505 /* The GCC node corresponding to the GNAT subprogram name. This can either
1506 be a FUNCTION_DECL node if we are dealing with a standard subprogram call,
1507 or an indirect reference expression (an INDIRECT_REF node) pointing to a
1508 subprogram. */
1510 /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */
1513 gnu_subprog_node);
1514 Entity_Id gnat_formal;
1515 Node_Id gnat_actual;
1520 tree gnu_subprog_call;
1523 {
1530 }
1534 /* If we are calling a stubbed function, make this into a raise of
1535 Program_Error. Elaborate all our args first. */
1538 {
1545 {
1549 }
1550 else
1552 }
1554 /* If we are calling by supplying a pointer to a target, set up that
1555 pointer as the first argument. Use GNU_TARGET if one was passed;
1556 otherwise, make a target by building a variable of the maximum size
1557 of the type. */
1559 {
1560 tree gnu_real_ret_type
1564 {
1565 tree gnu_obj_type
1573 }
1575 gnu_actual_list
1579 gnu_target,
1581 NULL_TREE);
1583 }
1585 /* The only way we can be making a call via an access type is if Name is an
1586 explicit dereference. In that case, get the list of formal args from the
1587 type the access type is pointing to. Otherwise, get the formals from
1588 entity being called. */
1592 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
1594 else
1597 /* Create the list of the actual parameters as GCC expects it, namely a chain
1598 of TREE_LIST nodes in which the TREE_VALUE field of each node is a
1599 parameter-expression and the TREE_PURPOSE field is null. Skip OUT
1600 parameters not passed by reference and don't need to be copied in. */
1605 {
1606 tree gnu_formal
1609 /* We treat a conversion between aggregate types as if it is an
1610 unchecked conversion. */
1611 bool unchecked_convert_p
1615 Node_Id gnat_name = (unchecked_convert_p
1619 tree gnu_actual;
1620 tree gnu_formal_type;
1622 /* If it's possible we may need to use this expression twice, make sure
1623 than any side-effects are handled via SAVE_EXPRs. Likewise if we need
1624 to force side-effects before the call.
1626 ??? This is more conservative than we need since we don't need to do
1627 this for pass-by-ref with no conversion. If we are passing a
1628 non-addressable Out or In Out parameter by reference, pass the address
1629 of a copy and set up to copy back out after the call. */
1631 {
1634 && gnu_formal
1639 {
1641 tree gnu_temp;
1643 /* For users of Starlet we issue a warning because the
1644 interface apparently assumes that by-ref parameters
1645 outlive the procedure invocation. The code still
1646 will not work as intended, but we cannot do much
1647 better since other low-level parts of the back-end
1648 would allocate temporaries at will because of the
1649 misalignment if we did not do so here. */
1652 {
1653 post_error
1655 gnat_actual);
1656 post_error_ne
1659 post_error_ne
1662 }
1664 /* Remove any unpadding on the actual and make a copy. But if
1665 the actual is a justified modular type, first convert
1666 to it. */
1670 && (TYPE_IS_PADDING_P
1679 /* Since we're going to take the address of the SAVE_EXPR, we
1680 don't want it to be marked as unchanging. So set
1681 TREE_ADDRESSABLE. */
1684 {
1687 }
1689 /* Set up to move the copy back to the original. */
1694 }
1695 }
1697 /* If this was a procedure call, we may not have removed any padding.
1698 So do it here for the part we will use as an input, if any. */
1704 gnu_actual);
1706 /* Unless this is an In parameter, we must remove any LJM building
1707 from GNU_NAME. */
1713 gnu_name);
1716 && !unchecked_convert_p
1720 /* Do any needed conversions. We need only check for unchecked
1721 conversion since normal conversions will be handled by just
1722 converting to the formal type. */
1724 {
1725 gnu_actual
1727 gnu_actual,
1732 /* One we've done the unchecked conversion, we still must ensure that
1733 the object is in range of the formal's type. */
1738 }
1740 /* We may have suppressed a conversion to the Etype of the actual since
1741 the parent is a procedure call. So add the conversion here. */
1743 gnu_actual);
1745 /* If we have not saved a GCC object for the formal, it means it is an
1746 OUT parameter not passed by reference and that does not need to be
1747 copied in. Otherwise, look at the PARM_DECL to see if it is passed by
1748 reference. */
1751 {
1753 {
1756 /* If we have a padded type, be sure we've removed padding. */
1761 gnu_actual);
1763 /* If we have the constructed subtype of an aliased object
1764 with an unconstrained nominal subtype, the type of the
1765 actual includes the template, although it is formally
1766 constrained. So we need to convert it back to the real
1767 constructed subtype to retrieve the constrained part
1768 and takes its address. */
1775 gnu_actual);
1776 }
1778 /* Otherwise, if we have a non-addressable COMPONENT_REF of a
1779 variable-size type see if it's doing a unpadding operation. If
1780 so, remove that operation since we have no way of allocating the
1781 required temporary. */
1791 /* The symmetry of the paths to the type of an entity is broken here
1792 since arguments don't know that they will be passed by ref. */
1795 }
1798 {
1805 {
1808 }
1810 /* Take the address of the object and convert to the proper pointer
1811 type. We'd like to actually compute the address of the beginning
1812 of the array using an ADDR_EXPR of an ARRAY_REF, but there's a
1813 possibility that the ARRAY_REF might return a constant and we'd be
1814 getting the wrong address. Neither approach is exactly correct,
1815 but this is the most likely to work in all cases. */
1818 gnu_actual));
1819 }
1822 {
1823 /* If arg is 'Null_Parameter, pass zero descriptor. */
1828 integer_zero_node);
1829 else
1832 gnat_formal));
1833 }
1834 else
1835 {
1844 /* If this is 'Null_Parameter, pass a zero even though we are
1845 dereferencing it. */
1850 BITS_PER_WORD))
1851 gnu_actual
1856 integer_zero_node),
1858 else
1860 }
1863 }
1867 NULL_TREE);
1869 /* If we return by passing a target, we emit the call and return the target
1870 as our result. */
1872 {
1874 *gnu_result_type_p
1877 }
1879 /* If it is a function call, the result is the call expression unless
1880 a target is specified, in which case we copy the result into the target
1881 and return the assignment statement. */
1883 {
1886 /* If the function returns an unconstrained array or by reference,
1887 we have to de-dereference the pointer. */
1895 else
1899 }
1901 /* If this is the case where the GNAT tree contains a procedure call
1902 but the Ada procedure has copy in copy out parameters, the special
1903 parameter passing mechanism must be used. */
1905 {
1906 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
1907 in copy out parameters. */
1912 {
1913 tree gnu_name;
1918 /* If any of the names had side-effects, ensure they are all
1919 evaluated before the call. */
1925 }
1929 else
1936 /* If we are dealing with a copy in copy out parameter, we must
1937 retrieve its value from the record returned in the call. */
1943 || (DECL_BY_DESCRIPTOR_P
1946 {
1947 /* Get the value to assign to this OUT or IN OUT parameter. It is
1948 either the result of the function if there is only a single such
1949 parameter or the appropriate field from the record returned. */
1950 tree gnu_result
1957 /* If the actual is a conversion, get the inner expression, which
1958 will be the real destination, and convert the result to the
1959 type of the actual parameter. */
1960 tree gnu_actual
1963 /* If the result is a padded type, remove the padding. */
1968 gnu_result);
1970 /* If the result is a type conversion, do it. */
1972 gnu_result
1973 = convert_with_check
1981 gnu_result,
1983 else
1984 {
1992 }
2000 }
2001 }
2002 else
2003 {
2006 }
2010 }
2011 \f
2012 /* Subroutine of gnat_to_gnu to translate gnat_node, an
2013 N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */
2015 static tree
2017 {
2020 /* If just annotating, ignore all EH and cleanups. */
2024 bool setjmp_longjmp
2030 tree gnu_result;
2031 tree gnu_expr;
2032 Node_Id gnat_temp;
2034 /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes
2035 and we have our own SJLJ mechanism. To call the GCC mechanism, we call
2036 add_cleanup, and when we leave the binding, end_stmt_group will create
2037 the TRY_FINALLY_EXPR.
2039 ??? The region level calls down there have been specifically put in place
2040 for a ZCX context and currently the order in which things are emitted
2041 (region/handlers) is different from the SJLJ case. Instead of putting
2042 other calls with different conditions at other places for the SJLJ case,
2043 it seems cleaner to reorder things for the SJLJ case and generalize the
2044 condition to make it not ZCX specific.
2046 If there are any exceptions or cleanup processing involved, we need an
2047 outer statement group (for Setjmp_Longjmp) and binding level. */
2049 {
2052 }
2054 /* If we are to call a function when exiting this block add a cleanup
2055 to the binding level we made above. */
2059 /* If using setjmp_longjmp, make the variables for the setjmp buffer and save
2060 area for address of previous buffer. Do this first since we need to have
2061 the setjmp buf known for any decls in this block. */
2063 {
2068 gnat_node);
2076 /* When we exit this block, restore the saved value. */
2078 }
2080 /* Now build the tree for the declarations and statements inside this block.
2081 If this is SJLJ, set our jmp_buf as the current buffer. */
2087 gnu_jmpbuf_decl)));
2093 /* Generate code for each statement in the block. */
2101 /* Now generate code for the two exception models, if either is relevant for
2102 this block. */
2104 {
2106 tree gnu_handler;
2108 /* Make a binding level for the exception handling declarations and code
2109 and set up gnu_except_ptr_stack for the handlers to use. */
2115 NULL_TREE,
2120 /* Generate code for each handler. The N_Exception_Handler case does the
2121 real work and returns a COND_EXPR for each handler, which we chain
2122 together here. */
2125 {
2128 /* If this is the first one, set it as the outer one. Otherwise,
2129 point the "else" part of the previous handler to us. Then point
2130 to our "else" part. */
2133 else
2137 }
2139 /* If none of the exception handlers did anything, re-raise but do not
2140 defer abortion. */
2147 else
2150 /* End the binding level dedicated to the exception handlers and get the
2151 whole statement group. */
2156 /* If the setjmp returns 1, we restore our incoming longjmp value and
2157 then check the handlers. */
2160 gnu_jmpsave_decl),
2161 gnat_node);
2165 /* This block is now "if (setjmp) ... <handlers> else <block>". */
2167 (build_call_1_expr
2170 gnu_jmpbuf_decl))),
2172 }
2174 {
2175 tree gnu_handlers;
2177 /* First make a block containing the handlers. */
2185 /* Now make the TRY_CATCH_EXPR for the block. */
2188 }
2189 else
2192 /* Now close our outer block, if we had to make one. */
2194 {
2198 }
2201 }
2202 \f
2203 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2204 to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp
2205 exception handling. */
2207 static tree
2209 {
2210 /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make
2211 an "if" statement to select the proper exceptions. For "Others", exclude
2212 exceptions where Handled_By_Others is nonzero unless the All_Others flag
2213 is set. For "Non-ada", accept an exception if "Lang" is 'V'. */
2216 Node_Id gnat_temp;
2220 {
2221 tree this_choice;
2224 {
2227 else
2228 this_choice
2229 = build_binary_op
2231 convert
2233 build_component_ref
2234 (build_unary_op
2239 integer_zero_node);
2240 }
2244 {
2246 tree gnu_expr;
2248 /* Exception may be a renaming. Recover original exception which is
2249 the one elaborated and registered. */
2255 this_choice
2256 = build_binary_op
2261 /* If this is the distinguished exception "Non_Ada_Error" (and we are
2262 in VMS mode), also allow a non-Ada exception (a VMS condition) t
2263 match. */
2265 {
2266 tree gnu_comp
2267 = build_component_ref
2272 this_choice
2273 = build_binary_op
2277 this_choice);
2278 }
2279 }
2280 else
2285 }
2288 }
2289 \f
2290 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2291 to a GCC tree, which is returned. This is the variant for ZCX. */
2293 static tree
2295 {
2297 tree gnu_expr;
2298 tree gnu_etype;
2299 tree gnu_current_exc_ptr;
2300 tree gnu_incoming_exc_ptr;
2301 Node_Id gnat_temp;
2303 /* We build a TREE_LIST of nodes representing what exception types this
2304 handler can catch, with special cases for others and all others cases.
2306 Each exception type is actually identified by a pointer to the exception
2307 id, or to a dummy object for "others" and "all others".
2309 Care should be taken to ensure that the control flow impact of "others"
2310 and "all others" is known to GCC. lang_eh_type_covers is doing the trick
2311 currently. */
2314 {
2316 {
2317 tree gnu_expr
2320 gnu_etype
2322 }
2325 {
2328 /* Exception may be a renaming. Recover original exception which is
2329 the one elaborated and registered. */
2336 /* The Non_Ada_Error case for VMS exceptions is handled
2337 by the personality routine. */
2338 }
2339 else
2342 /* The GCC interface expects NULL to be passed for catch all handlers, so
2343 it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype
2344 is integer_zero_node. It would not work, however, because GCC's
2345 notion of "catch all" is stronger than our notion of "others". Until
2346 we correctly use the cleanup interface as well, doing that would
2347 prevent the "all others" handlers from being seen, because nothing
2348 can be caught beyond a catch all from GCC's point of view. */
2350 }
2355 /* Expand a call to the begin_handler hook at the beginning of the handler,
2356 and arrange for a call to the end_handler hook to occur on every possible
2357 exit path.
2359 The hooks expect a pointer to the low level occurrence. This is required
2360 for our stack management scheme because a raise inside the handler pushes
2361 a new occurrence on top of the stack, which means that this top does not
2362 necessarily match the occurrence this handler was dealing with.
2364 The EXC_PTR_EXPR object references the exception occurrence being
2365 propagated. Upon handler entry, this is the exception for which the
2366 handler is triggered. This might not be the case upon handler exit,
2367 however, as we might have a new occurrence propagated by the handler's
2368 body, and the end_handler hook called as a cleanup in this context.
2370 We use a local variable to retrieve the incoming value at handler entry
2371 time, and reuse it to feed the end_handler hook's argument at exit. */
2376 gnat_node);
2379 gnu_incoming_exc_ptr),
2380 gnat_node);
2387 }
2388 \f
2389 /* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */
2391 static void
2393 {
2394 /* Make the decl for the elaboration procedure. */
2399 tree gnu_elab_proc_decl
2400 = create_subprog_decl
2404 gnat_unit_entity);
2414 /* For a body, first process the spec if there is one. */
2423 {
2430 }
2436 /* Process any pragmas and actions following the unit. */
2440 /* Save away what we've made so far and record this potential elaboration
2441 procedure. */
2451 /* Generate elaboration code for this unit, if necessary, and say whether
2452 we did or not. */
2455 /* Generate functions to call static constructors and destructors
2456 for targets that do not support .ctors/.dtors sections. These
2457 functions have magic names which are detected by collect2. */
2463 }
2464 \f
2465 /* This function is the driver of the GNAT to GCC tree transformation
2466 process. It is the entry point of the tree transformer. GNAT_NODE is the
2467 root of some GNAT tree. Return the root of the corresponding GCC tree.
2468 If this is an expression, return the GCC equivalent of the expression. If
2469 it is a statement, return the statement. In the case when called for a
2470 statement, it may also add statements to the current statement group, in
2471 which case anything it returns is to be interpreted as occurring after
2472 anything `it already added. */
2474 tree
2476 {
2480 tree gnu_expr;
2482 Node_Id gnat_temp;
2484 /* Save node number for error message and set location information. */
2492 /* If this node is a non-static subexpression and we are only
2493 annotating types, make this into a NULL_EXPR. */
2501 /* If this is a Statement and we are at top level, it must be part of
2502 the elaboration procedure, so mark us as being in that procedure
2503 and push our context. */
2515 {
2520 }
2523 {
2524 /********************************/
2525 /* Chapter 2: Lexical Elements: */
2526 /********************************/
2536 {
2537 tree gnu_type;
2539 /* Get the type of the result, looking inside any padding and
2540 justified modular types. Then get the value in that type. */
2549 /* If the result overflows (meaning it doesn't fit in its base type),
2550 abort. We would like to check that the value is within the range
2551 of the subtype, but that causes problems with subtypes whose usage
2552 will raise Constraint_Error and with biased representation, so
2553 we don't. */
2555 }
2559 /* If a Entity is present, it means that this was one of the
2560 literals in a user-defined character type. In that case,
2561 just return the value in the CONST_DECL. Otherwise, use the
2562 character code. In that case, the base type should be an
2563 INTEGER_TYPE, but we won't bother checking for that. */
2567 else
2568 gnu_result
2569 = force_fit_type
2570 (build_int_cst
2576 /* If this is of a fixed-point type, the value we want is the
2577 value of the corresponding integer. */
2579 {
2582 gnu_result_type);
2584 }
2586 /* We should never see a Vax_Float type literal, since the front end
2587 is supposed to transform these using appropriate conversions */
2591 else
2592 {
2597 /* If the real value is zero, so is the result. Otherwise,
2598 convert it to a machine number if it isn't already. That
2599 forces BASE to 0 or 2 and simplifies the rest of our logic. */
2602 else
2603 {
2605 ur_realval
2609 gnu_result
2612 /* If we have a base of zero, divide by the denominator.
2613 Otherwise, the base must be 2 and we scale the value, which
2614 we know can fit in the mantissa of the type (hence the use
2615 of that type above). */
2617 gnu_result
2620 gnu_result,
2622 gnu_result_type));
2623 else
2624 {
2625 REAL_VALUE_TYPE tmp;
2631 }
2632 }
2634 /* Now see if we need to negate the result. Do it this way to
2635 properly handle -0. */
2637 gnu_result
2639 gnu_result);
2640 }
2647 {
2653 /* Build the string with the characters in the literal. Note
2654 that Ada strings are 1-origin. */
2658 /* Put a null at the end of the string in case it's in a context
2659 where GCC will want to treat it as a C string. */
2664 /* Strings in GCC don't normally have types, but we want
2665 this to not be converted to the array type. */
2667 }
2668 else
2669 {
2670 /* Build a list consisting of each character, then make
2671 the aggregate. */
2679 {
2680 gnu_list
2685 gnu_list);
2689 }
2691 gnu_result
2693 }
2700 /**************************************/
2701 /* Chapter 3: Declarations and Types: */
2702 /**************************************/
2719 /* If we are just annotating types and this object has an unconstrained
2720 or task type, don't elaborate it. */
2731 && (!type_annotate_only
2733 {
2738 /* If this object has its elaboration delayed, we must force
2739 evaluation of GNU_EXPR right now and save it for when the object
2740 is frozen. */
2742 {
2745 gnu_expr
2750 else
2754 }
2755 }
2756 else
2769 /* Don't do anything if this renaming is handled by the front end or if
2770 we are just annotating types and this object has a composite or task
2771 type, don't elaborate it. We return the result in case it has any
2772 SAVE_EXPRs in it that need to be evaluated here. */
2774 && ! (type_annotate_only
2778 gnu_result
2781 else
2794 /* These are fully handled in the front end. */
2798 /*************************************/
2799 /* Chapter 4: Names and Expressions: */
2800 /*************************************/
2809 {
2811 tree gnu_type;
2819 /* If we got a padded type, remove it too. */
2822 gnu_array_object
2824 gnu_array_object);
2828 /* First compute the number of dimensions of the array, then
2829 fill the expression array, the order depending on whether
2830 this is a Convention_Fortran array or not. */
2835 ;
2844 else
2852 {
2858 gnu_expr
2859 = emit_index_check
2866 }
2867 }
2873 {
2874 tree gnu_type;
2880 /* Do any implicit dereferences of the prefix and do any needed
2881 range check. */
2886 {
2887 /* Get the bounds of the slice. */
2888 tree gnu_index_type
2894 /* Check to see that the minimum slice value is in range */
2895 gnu_expr_l
2896 = emit_index_check
2901 /* Check to see that the maximum slice value is in range */
2902 gnu_expr_h
2903 = emit_index_check
2908 /* Derive a good type to convert everything too */
2911 /* Build a compound expression that does the range checks */
2912 gnu_expr
2917 /* Build a conditional expression that returns the range checks
2918 expression if the slice range is not null (max >= min) or
2919 returns the min if the slice range is null */
2920 gnu_expr
2924 gnu_max_expr),
2926 gnu_min_expr)),
2928 }
2929 else
2934 }
2938 {
2942 tree gnu_field;
2946 {
2951 }
2955 /* For discriminant references in tagged types always substitute the
2956 corresponding discriminant as the actual selected component. */
2962 /* For discriminant references of untagged types always substitute the
2963 corresponding stored discriminant. */
2968 /* Handle extracting the real or imaginary part of a complex.
2969 The real part is the first field and the imaginary the last. */
2975 else
2976 {
2979 /* If there are discriminants, the prefix might be
2980 evaluated more than once, which is a problem if it has
2981 side-effects. */
2988 gnu_result
2992 }
2996 }
3000 {
3001 /* The attribute designator (like an enumeration value). */
3004 /* The Elab_Spec and Elab_Body attributes are special in that
3005 Prefix is a unit, not an object with a GCC equivalent. Similarly
3006 for Elaborated, since that variable isn't otherwise known. */
3010 attribute == Attr_Elab_Body
3013 gnat_node));
3016 }
3020 /* Like 'Access as far as we are concerned. */
3028 {
3029 tree gnu_aggr_type;
3031 /* ??? It is wrong to evaluate the type now, but there doesn't
3032 seem to be any other practical way of doing it. */
3036 gnu_aggr_type = gnu_result_type
3041 gnu_aggr_type
3049 {
3050 /* The first element is the discrimant, which we ignore. The
3051 next is the field we're building. Convert the expression
3052 to the type of the field and then to the union type. */
3053 Node_Id gnat_assoc
3056 tree gnu_field_type
3061 }
3064 gnu_result
3066 gnu_aggr_type);
3069 gnu_aggr_type,
3072 gnu_result
3073 = build_binary_op
3078 (Next
3080 else
3084 }
3094 /* Get the operand expression. */
3098 gnu_result
3110 /* If the result is a pointer type, see if we are improperly
3111 converting to a stricter alignment. */
3115 {
3121 post_error_ne_tree_2
3125 }
3133 {
3136 tree gnu_low;
3137 tree gnu_high;
3139 /* GNAT_RANGE is either an N_Range node or an identifier
3140 denoting a subtype. */
3142 {
3145 }
3148 {
3153 }
3154 else
3159 /* If LOW and HIGH are identical, perform an equality test.
3160 Otherwise, ensure that GNU_OBJECT is only evaluated once
3161 and perform a full range test. */
3165 else
3166 {
3168 gnu_result
3174 }
3178 }
3186 ? RDIV_EXPR
3193 /* These can either be operations on booleans or on modular types.
3194 Fall through for boolean types since that's the way GNU_CODES is
3195 set up. */
3197 Modular_Integer_Kind))
3198 {
3199 enum tree_code code
3210 }
3212 /* ... fall through ... */
3224 {
3226 tree gnu_type;
3232 /* If this is a comparison operator, convert any references to
3233 an unconstrained array value into a reference to the
3234 actual array. */
3236 {
3239 }
3241 /* If the result type is a private type, its full view may be a
3242 numeric subtype. The representation we need is that of its base
3243 type, given that it is the result of an arithmetic operation. */
3245 gnu_type = gnu_result_type
3248 /* If this is a shift whose count is not guaranteed to be correct,
3249 we need to adjust the shift count. */
3252 {
3254 tree gnu_max_shift
3262 gnu_rhs
3263 = build_binary_op
3266 gnu_count_type,
3267 gnu_max_shift,
3269 integer_one_node)),
3270 gnu_rhs);
3271 }
3273 /* For right shifts, the type says what kind of shift to do,
3274 so we may need to choose a different type. */
3283 {
3286 }
3290 /* If this is a logical shift with the shift count not verified,
3291 we must return zero if it is too large. We cannot compensate
3292 above in this case. */
3296 gnu_result
3297 = build_cond_expr
3300 gnu_rhs,
3304 gnu_result);
3305 }
3309 {
3312 tree gnu_false
3319 }
3328 /* This case can apply to a boolean or a modular type.
3329 Fall through for a boolean operand since GNU_CODES is set
3330 up to handle this. */
3332 {
3336 gnu_expr);
3338 }
3340 /* ... fall through ... */
3347 else
3356 {
3358 tree gnu_type;
3363 /* The Expression operand can either be an N_Identifier or
3364 Expanded_Name, which must represent a type, or a
3365 N_Qualified_Expression, which contains both the object type and an
3366 initial value for the object. */
3371 {
3372 Entity_Id gnat_desig_type
3384 {
3387 }
3388 else
3389 {
3395 }
3396 }
3397 else
3404 ignore_init_type);
3405 }
3408 /***************************/
3409 /* Chapter 5: Statements: */
3410 /***************************/
3422 /* Get the LHS and RHS of the statement and convert any reference to an
3423 unconstrained array into a reference to the underlying array.
3424 If we are not to do range checking and the RHS is an N_Function_Call,
3425 pass the LHS to the call function. */
3428 /* If the type has a size that overflows, convert this into raise of
3429 Storage_Error: execution shouldn't have gotten here anyway. */
3437 else
3438 {
3439 gnu_rhs
3442 /* If range check is needed, emit code to generate it */
3446 gnu_result
3448 }
3452 {
3455 /* Make the outer COND_EXPR. Avoid non-determinism. */
3464 /* Now make a COND_EXPR for each of the "else if" parts. Put each
3465 into the previous "else" part and point to where to put any
3466 outer "else". Also avoid non-determinism. */
3470 {
3480 }
3483 }
3507 gnu_result
3517 {
3518 /* The gnu function type of the subprogram currently processed. */
3520 /* The return value from the subprogram. */
3522 /* The place to put the return value. */
3523 tree gnu_lhs;
3524 /* Avoid passing error_mark_node to RETURN_EXPR. */
3527 /* If we are dealing with a "return;" from an Ada procedure with
3528 parameters passed by copy in copy out, we need to return a record
3529 containing the final values of these parameters. If the list
3530 contains only one entry, return just that entry.
3532 For a full description of the copy in copy out parameter mechanism,
3533 see the part of the gnat_to_gnu_entity routine dealing with the
3534 translation of subprograms.
3536 But if we have a return label defined, convert this into
3537 a branch to that label. */
3540 {
3544 }
3547 {
3551 else
3552 gnu_ret_val
3555 }
3557 /* If the Ada subprogram is a function, we just need to return the
3558 expression. If the subprogram returns an unconstrained
3559 array, we have to allocate a new version of the result and
3560 return it. If we return by reference, return a pointer. */
3563 {
3564 /* If the current function returns by target pointer and we
3565 are doing a call, pass that target to the call. */
3568 {
3569 gnu_lhs
3574 }
3575 else
3576 {
3580 /* The original return type was unconstrained so dereference
3581 the TARGET pointer in the actual return value's type. */
3582 gnu_lhs
3585 else
3588 /* Do not remove the padding from GNU_RET_VAL if the inner
3589 type is self-referential since we want to allocate the fixed
3590 size in that case. */
3594 && (TYPE_IS_PADDING_P
3596 && (CONTAINS_PLACEHOLDER_P
3602 gnu_ret_val
3606 {
3609 /* We have two cases: either the function returns with
3610 depressed stack or not. If not, we allocate on the
3611 secondary stack. If so, we allocate in the stack frame.
3612 if no copy is needed, the front end will set By_Ref,
3613 which we handle in the case above. */
3615 gnu_ret_val
3617 gnu_ret_val,
3620 else
3621 gnu_ret_val
3623 gnu_ret_val,
3628 }
3629 }
3630 }
3637 {
3640 }
3643 }
3651 /****************************/
3652 /* Chapter 6: Subprograms: */
3653 /****************************/
3656 /* Unless there is a freeze node, declare the subprogram. We consider
3657 this a "definition" even though we're not generating code for
3658 the subprogram because we will be making the corresponding GCC
3659 node here. */
3668 /* This subprogram doesn't exist for code generation purposes, but we
3669 have to elaborate the types of any parameters, unless they are
3670 imported types (nothing to generate in this case). */
3683 /* For a child unit identifier go up a level to get the
3684 specification. We get this when we try to find the spec of
3685 a child unit package that is the compilation unit being compiled. */
3699 /*************************/
3700 /* Chapter 7: Packages: */
3701 /*************************/
3717 /* If this is the body of a generic package - do nothing */
3719 {
3722 }
3733 /*********************************/
3734 /* Chapter 8: Visibility Rules: */
3735 /*********************************/
3739 /* Nothing to do here - but these may appear in list of declarations */
3743 /***********************/
3744 /* Chapter 9: Tasks: */
3745 /***********************/
3756 /***********************************************************/
3757 /* Chapter 10: Program Structure and Compilation Issues: */
3758 /***********************************************************/
3762 /* This is not called for the main unit, which is handled in function
3763 gigi above. */
3775 /* Simply process whatever unit is being inserted. */
3783 /***************************/
3784 /* Chapter 11: Exceptions: */
3785 /***************************/
3788 /* If there is an At_End procedure attached to this node, and the EH
3789 mechanism is SJLJ, we must have at least a corresponding At_End
3790 handler, unless the No_Exception_Handlers restriction is set. */
3805 else
3810 /*******************************/
3811 /* Chapter 12: Generic Units: */
3812 /*******************************/
3822 /* These nodes can appear on a declaration list but there is nothing to
3823 to be done with them. */
3827 /***************************************************/
3828 /* Chapter 13: Representation Clauses and */
3829 /* Implementation-Dependent Features: */
3830 /***************************************************/
3836 /* The only one we need deal with is for 'Address. For the others, SEM
3837 puts the information elsewhere. We need only deal with 'Address
3838 if the object has a Freeze_Node (which it never will currently). */
3843 /* Get the value to use as the address and save it as the
3844 equivalent for GNAT_TEMP. When the object is frozen,
3845 gnat_to_gnu_entity will do the right thing. */
3853 /* We do nothing with these. SEM puts the information elsewhere. */
3859 {
3865 /* First process inputs, then outputs, then clobbers. */
3868 {
3873 gnu_input_list
3876 }
3880 {
3885 gnu_output_list
3888 }
3892 gnu_clobber_list
3895 gnu_clobber_list);
3903 }
3904 else
3909 /***************************************************/
3910 /* Added Nodes */
3911 /***************************************************/
3929 {
3931 tree gnu_obj_type;
3932 tree gnu_obj_size;
3935 /* If this is a thin pointer, we must dereference it to create
3936 a fat pointer, then go back below to a thin pointer. The
3937 reason for this is that we need a fat pointer someplace in
3938 order to properly compute the size. */
3942 gnu_ptr));
3944 /* If this is an unconstrained array, we know the object must
3945 have been allocated with the template in front of the object.
3946 So pass the template address, but get the total size. Do this
3947 by converting to a thin pointer. */
3949 gnu_ptr
3951 (TYPE_OBJECT_RECORD_TYPE
3953 gnu_ptr);
3961 {
3964 tree gnu_byte_offset
3971 }
3976 gnat_node);
3977 }
3984 {
3987 }
3992 /* If the type is VOID, this is a statement, so we need to
3993 generate the code for the call. Handle a Condition, if there
3994 is one. */
3996 {
4003 }
4004 else
4009 /* If the result is a pointer type, see if we are either converting
4010 from a non-pointer or from a pointer to a type with a different
4011 alias set and warn if so. If the result defined in the same unit as
4012 this unchecked conversion, we can allow this because we can know to
4013 make that type have alias set 0. */
4014 {
4025 {
4026 post_error_ne
4029 post_error
4031 gnat_node);
4032 post_error_ne
4035 }
4037 /* The No_Strict_Aliasing flag is not propagated to the back-end for
4038 fat pointers so unconditionally warn in problematic cases. */
4040 {
4041 tree array_type
4048 {
4049 post_error_ne
4052 post_error
4054 gnat_node);
4055 }
4056 }
4057 }
4070 }
4072 /* If we pushed our level as part of processing the elaboration routine,
4073 pop it back now. */
4075 {
4080 }
4082 /* Set the location information into the result. Note that we may have
4083 no result if we tried to build a CALL_EXPR node to a procedure with
4084 no side-effects and optimization is enabled. */
4088 /* If we're supposed to return something of void_type, it means we have
4089 something we're elaborating for effect, so just return. */
4093 /* If the result is a constant that overflows, raise constraint error. */
4096 {
4099 gnu_result
4102 }
4104 /* If our result has side-effects and is of an unconstrained type,
4105 make a SAVE_EXPR so that we can be sure it will only be referenced
4106 once. Note we must do this before any conversions. */
4112 /* Now convert the result to the proper type. If the type is void or if
4113 we have no result, return error_mark_node to show we have no result.
4114 If the type of the result is correct or if we have a label (which doesn't
4115 have any well-defined type), return our result. Also don't do the
4116 conversion if the "desired" type involves a PLACEHOLDER_EXPR in its size
4117 since those are the cases where the front end may have the type wrong due
4118 to "instantiating" the unconstrained record with discriminant values
4119 or if this is a FIELD_DECL. If this is the Name of an assignment
4120 statement or a parameter of a procedure call, return what we have since
4121 the RHS has to be converted to our type there in that case, unless
4122 GNU_RESULT_TYPE has a simpler size. Similarly, if the two types are
4123 record types with the same name, the expression type has integral mode,
4124 and GNU_RESULT_TYPE BLKmode, don't convert. This will be the case when
4125 we are converting from a packable type to its actual type and we need
4126 those conversions to be NOPs in order for assignments into these types to
4127 work properly if the inner object is a bitfield and hence can't have
4128 its address taken. Finally, don't convert integral types that are the
4129 operand of an unchecked conversion since we need to ignore those
4130 conversions (for 'Valid). Otherwise, convert the result to the proper
4131 type. */
4151 && (CONTAINS_PLACEHOLDER_P
4155 {
4156 /* In this case remove padding only if the inner object is of
4157 self-referential size: in that case it must be an object of
4158 unconstrained type with a default discriminant. In other cases,
4159 we want to avoid copying too much data. */
4166 gnu_result);
4167 }
4183 {
4184 /* Remove any padding record, but do nothing more in this case. */
4188 gnu_result);
4189 }
4197 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RESULT. */
4204 }
4205 \f
4206 /* Record the current code position in GNAT_NODE. */
4208 static void
4210 {
4215 }
4217 /* Insert the code for GNAT_NODE at the position saved for that node. */
4219 static void
4221 {
4224 }
4225 \f
4226 /* Start a new statement group chained to the previous group. */
4228 static void
4230 {
4233 /* First see if we can get one from the free list. */
4236 else
4242 }
4244 /* Add GNU_STMT to the current statement group. */
4246 void
4248 {
4251 /* If we're at top level, show everything in here is in use in case
4252 any of it is shared by a subprogram. */
4256 }
4258 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE. */
4260 void
4262 {
4266 }
4268 /* Add a declaration statement for GNU_DECL to the current statement group.
4269 Get SLOC from Entity_Id. */
4271 void
4273 {
4274 tree gnu_stmt;
4276 /* If this is a variable that Gigi is to ignore, we may have been given
4277 an ERROR_MARK. So test for it. We also might have been given a
4278 reference for a renaming. So only do something for a decl. Also
4279 ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */
4285 /* If we are global, we don't want to actually output the DECL_EXPR for
4286 this decl since we already have evaluated the expressions in the
4287 sizes and positions as globals and doing it again would be wrong.
4288 But we do have to mark everything as used. */
4292 else
4293 {
4297 {
4301 }
4302 }
4304 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set,
4305 there are two cases we need to handle here. */
4307 {
4311 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set
4312 and decl has a padded type, convert it to the unpadded type so the
4313 assignment is done properly. */
4316 gnu_lhs
4319 /* Otherwise, if this is going into memory and the initializer isn't
4320 valid for the assembler and loader. Gimplification could do this,
4321 but would be run too late if -fno-unit-at-a-time. */
4328 {
4329 tree gnu_assign_stmt
4338 }
4339 }
4340 }
4342 /* Utility function to mark nodes with TREE_VISITED and types as having their
4343 sized gimplified. Called from walk_tree. We use this to indicate all
4344 variable sizes and positions in global types may not be shared by any
4345 subprogram. */
4347 static tree
4349 {
4353 /* Don't mark a dummy type as visited because we want to mark its sizes
4354 and fields once it's filled in. */
4362 }
4364 /* Likewise, but to mark as unvisited. */
4366 static tree
4369 {
4373 }
4375 /* Add GNU_CLEANUP, a cleanup action, to the current code group. */
4377 static void
4379 {
4381 }
4383 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */
4385 void
4387 {
4390 }
4392 /* Return code corresponding to the current code group. It is normally
4393 a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
4394 BLOCK or cleanups were set. */
4396 static tree
4398 {
4402 /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there
4403 are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK,
4404 make a BIND_EXPR. Note that we nest in that because the cleanup may
4405 reference variables in the block. */
4417 /* Remove this group from the stack and add it to the free list. */
4423 }
4425 /* Add a list of statements from GNAT_LIST, a possibly-empty list of
4426 statements.*/
4428 static void
4430 {
4431 Node_Id gnat_node;
4437 }
4439 /* Build a tree from GNAT_LIST, a possibly-empty list of statements.
4440 If BINDING_P is true, push and pop a binding level around the list. */
4442 static tree
4444 {
4454 }
4455 \f
4456 /* Push and pop routines for stacks. We keep a free list around so we
4457 don't waste tree nodes. */
4459 static void
4461 {
4465 {
4470 }
4471 else
4475 }
4477 static void
4479 {
4485 }
4486 \f
4487 /* GNU_STMT is a statement. We generate code for that statement. */
4489 void
4491 {
4492 #if 0
4494 #endif
4497 {
4498 #if 0
4500 /* First write a volatile ASM_INPUT to prevent anything from being
4501 moved. */
4507 modifier);
4510 #endif
4514 }
4515 }
4516 \f
4517 /* Generate GIMPLE in place for the expression at *EXPR_P. */
4519 int
4521 {
4528 {
4530 /* If this is for a scalar, just make a VAR_DECL for it. If for
4531 an aggregate, get a null pointer of the appropriate type and
4532 dereference it. */
4536 integer_zero_node));
4537 else
4538 {
4541 }
4547 /* We should only do this if we are just elaborating for side-effects,
4548 but we can't know that yet. */
4553 /* If we're taking the address of a constant CONSTRUCTOR, force it to
4554 be put into static memory. We know it's going to be readonly given
4555 the semantics we have and it's required to be static memory in
4556 the case when the reference is in an elaboration procedure. */
4559 {
4560 tree new_var
4571 }
4575 /* We have a kludge here. If the FIELD_DECL is from a fat pointer and is
4576 from an early dummy type, replace it with the proper FIELD_DECL. */
4579 {
4583 }
4585 /* ... fall through ... */
4589 }
4590 }
4592 /* Generate GIMPLE in place for the statement at *STMT_P. */
4594 static enum gimplify_status
4596 {
4600 {
4610 {
4614 /* Set to emit the statements of the loop. */
4617 /* We first emit the start label and then a conditional jump to
4618 the end label if there's a top condition, then the body of the
4619 loop, then a conditional branch to the end label, then the update,
4620 if any, and finally a jump to the start label and the definition
4621 of the end label. */
4623 gnu_start_label),
4624 stmt_p);
4631 void_type_node,
4632 gnu_end_label)),
4633 stmt_p);
4642 void_type_node,
4643 gnu_end_label)),
4644 stmt_p);
4650 gnu_start_label),
4651 stmt_p);
4653 gnu_end_label),
4654 stmt_p);
4656 }
4659 /* Build a statement to jump to the corresponding end label, then
4660 see if it needs to be conditional. */
4669 }
4670 }
4671 \f
4672 /* Force references to each of the entities in packages GNAT_NODE with's
4673 so that the debugging information for all of them are identical
4674 in all clients. Operate recursively on anything it with's, but check
4675 that we aren't elaborating something more than once. */
4677 /* The reason for this routine's existence is two-fold.
4678 First, with some debugging formats, notably MDEBUG on SGI
4679 IRIX, the linker will remove duplicate debugging information if two
4680 clients have identical debugguing information. With the normal scheme
4681 of elaboration, this does not usually occur, since entities in with'ed
4682 packages are elaborated on demand, and if clients have different usage
4683 patterns, the normal case, then the order and selection of entities
4684 will differ. In most cases however, it seems that linkers do not know
4685 how to eliminate duplicate debugging information, even if it is
4686 identical, so the use of this routine would increase the total amount
4687 of debugging information in the final executable.
4689 Second, this routine is called in type_annotate mode, to compute DDA
4690 information for types in withed units, for ASIS use */
4692 static void
4694 {
4697 /* Process each unit only once. As we trace the context of all relevant
4698 units transitively, including generic bodies, we may encounter the
4699 same generic unit repeatedly */
4704 /* Save entities in all context units. A body may have an implicit_with
4705 on its own spec, if the context includes a child unit, so don't save
4706 the spec twice. */
4714 {
4718 {
4735 }
4737 {
4738 Node_Id gnat_body
4741 /* Retrieve compilation unit node of generic body. */
4746 /* If body is available, elaborate its context. */
4749 }
4750 }
4754 }
4755 \f
4756 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
4758 static void
4760 {
4762 tree gnu_old;
4763 tree gnu_new;
4764 tree gnu_init
4769 /* If this is a package, need to generate code for the package. */
4771 {
4772 insert_code_for
4776 }
4778 /* Check for old definition after the above call. This Freeze_Node
4779 might be for one its Itypes. */
4780 gnu_old
4783 /* If this entity has an Address representation clause, GNU_OLD is the
4784 address, so discard it here. */
4788 /* Don't do anything for class-wide types they are always
4789 transformed into their root type. */
4795 /* Don't do anything for subprograms that may have been elaborated before
4796 their freeze nodes. This can happen, for example because of an inner call
4797 in an instance body, or a previous compilation of a spec for inlining
4798 purposes. */
4803 || (gnu_old
4808 /* If we have a non-dummy type old tree, we have nothing to do. Unless
4809 this is the public view of a private type whose full view was not
4810 delayed, this node was never delayed as it should have been.
4811 Also allow this to happen for concurrent types since we may have
4812 frozen both the Corresponding_Record_Type and this type. */
4816 {
4822 }
4824 /* Reset the saved tree, if any, and elaborate the object or type for real.
4825 If there is a full declaration, elaborate it and copy the type to
4826 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
4827 a class wide type or subtype. */
4829 {
4838 }
4842 {
4845 /* Propagate back-annotations from full view to partial view. */
4855 /* The above call may have defined this entity (the simplest example
4856 of this is when we have a private enumeral type since the bounds
4857 will have the public view. */
4863 }
4864 else
4867 /* If we've made any pointers to the old version of this type, we
4868 have to update them. */
4872 }
4873 \f
4874 /* Process the list of inlined subprograms of GNAT_NODE, which is an
4875 N_Compilation_Unit. */
4877 static void
4879 {
4880 Entity_Id gnat_entity;
4881 Node_Id gnat_body;
4883 /* If we can inline, generate RTL for all the inlined subprograms.
4884 Define the entity first so we set DECL_EXTERNAL. */
4889 {
4893 {
4894 /* ??? This really should always be Present. */
4898 gnat_body
4900 }
4903 {
4906 }
4907 }
4908 }
4909 \f
4910 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
4911 We make two passes, one to elaborate anything other than bodies (but
4912 we declare a function if there was no spec). The second pass
4913 elaborates the bodies.
4915 GNAT_END_LIST gives the element in the list past the end. Normally,
4916 this is Empty, but can be First_Real_Statement for a
4917 Handled_Sequence_Of_Statements.
4919 We make a complete pass through both lists if PASS1P is true, then make
4920 the second pass over both lists if PASS2P is true. The lists usually
4921 correspond to the public and private parts of a package. */
4923 static void
4926 {
4928 Node_Id gnat_decl;
4938 {
4939 /* For package specs, we recurse inside the declarations,
4940 thus taking the two pass approach inside the boundary. */
4948 /* Similarly for any declarations in the actions of a
4949 freeze node. */
4951 {
4954 }
4956 /* Package bodies with freeze nodes get their elaboration deferred
4957 until the freeze node, but the code must be placed in the right
4958 place, so record the code position now. */
4966 (Corresponding_Spec
4969 record_code_position
4972 /* We defer most subprogram bodies to the second pass. */
4974 {
4976 {
4982 }
4983 }
4984 /* For bodies and stubs that act as their own specs, the entity
4985 itself must be elaborated in the first pass, because it may
4986 be used in other declarations. */
4988 {
4989 Node_Id gnat_subprog_id =
4996 }
4998 /* Concurrent stubs stand for the corresponding subprogram bodies,
4999 which are deferred like other bodies. */
5002 ;
5003 else
5005 }
5007 /* Here we elaborate everything we deferred above except for package bodies,
5008 which are elaborated at their freeze nodes. Note that we must also
5009 go inside things (package specs and freeze nodes) the first pass did. */
5015 {
5031 }
5032 }
5033 \f
5034 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
5035 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
5036 which we have to check. */
5038 static tree
5040 {
5046 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
5047 we can't do anything since we might be truncating the bounds. No
5048 check is needed in this case. */
5054 /* Checked expressions must be evaluated only once. */
5057 /* There's no good type to use here, so we might as well use
5058 integer_type_node. Note that the form of the check is
5059 (not (expr >= lo)) or (not (expr >= hi))
5060 the reason for this slightly convoluted form is that NaN's
5061 are not considered to be in range in the float case. */
5062 return emit_check
5064 invert_truthvalue
5068 invert_truthvalue
5072 gnu_high)))),
5074 }
5075 \f
5076 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
5077 which we are about to index, GNU_EXPR is the index expression to be
5078 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
5079 against which GNU_EXPR has to be checked. Note that for index
5080 checking we cannot use the emit_range_check function (although very
5081 similar code needs to be generated in both cases) since for index
5082 checking the array type against which we are checking the indeces
5083 may be unconstrained and consequently we need to retrieve the
5084 actual index bounds from the array object itself
5085 (GNU_ARRAY_OBJECT). The place where we need to do that is in
5086 subprograms having unconstrained array formal parameters */
5088 static tree
5090 tree gnu_expr,
5091 tree gnu_low,
5092 tree gnu_high)
5093 {
5094 tree gnu_expr_check;
5096 /* Checked expressions must be evaluated only once. */
5099 /* Must do this computation in the base type in case the expression's
5100 type is an unsigned subtypes. */
5103 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
5104 the object we are handling. */
5108 /* There's no good type to use here, so we might as well use
5109 integer_type_node. */
5110 return emit_check
5113 gnu_expr_check,
5115 gnu_low)),
5117 gnu_expr_check,
5119 gnu_high))),
5121 }
5122 \f
5123 /* GNU_COND contains the condition corresponding to an access, discriminant or
5124 range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if
5125 GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true.
5126 REASON is the code that says why the exception was raised. */
5128 static tree
5130 {
5131 tree gnu_call;
5132 tree gnu_result;
5136 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
5137 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
5138 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
5139 out. */
5143 gnu_expr));
5145 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
5146 protect it. Otherwise, show GNU_RESULT has no side effects: we
5147 don't need to evaluate it just for the check. */
5149 gnu_result
5151 else
5154 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
5155 we will repeatedly do the test. It would be nice if GCC was able
5156 to optimize this and only do it once. */
5158 }
5159 \f
5160 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
5161 overflow checks if OVERFLOW_P is nonzero and range checks if
5162 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
5163 If TRUNCATE_P is nonzero, do a float to integer conversion with
5164 truncation; otherwise round. */
5166 static tree
5169 {
5177 /* If we are not doing any checks, the output is an integral type, and
5178 the input is not a floating type, just do the conversion. This
5179 shortcut is required to avoid problems with packed array types
5180 and simplifies code in all cases anyway. */
5185 /* First convert the expression to its base type. This
5186 will never generate code, but makes the tests below much simpler.
5187 But don't do this if converting from an integer type to an unconstrained
5188 array type since then we need to get the bounds from the original
5189 (unpacked) type. */
5193 /* If overflow checks are requested, we need to be sure the result will
5194 fit in the output base type. But don't do this if the input
5195 is integer and the output floating-point. */
5198 {
5199 /* Ensure GNU_EXPR only gets evaluated once. */
5207 /* Convert the lower bounds to signed types, so we're sure we're
5208 comparing them properly. Likewise, convert the upper bounds
5209 to unsigned types. */
5223 /* Check each bound separately and only if the result bound
5224 is tighter than the bound on the input type. Note that all the
5225 types are base types, so the bounds must be constant. Also,
5226 the comparison is done in the base type of the input, which
5227 always has the proper signedness. First check for input
5228 integer (which means output integer), output float (which means
5229 both float), or mixed, in which case we always compare.
5230 Note that we have to do the comparison which would *fail* in the
5231 case of an error since if it's an FP comparison and one of the
5232 values is a NaN or Inf, the comparison will fail. */
5239 gnu_cond
5240 = invert_truthvalue
5243 gnu_out_lb)));
5251 gnu_cond
5253 invert_truthvalue
5255 gnu_input,
5257 gnu_out_ub))));
5261 CE_Overflow_Check_Failed);
5262 }
5264 /* Now convert to the result base type. If this is a non-truncating
5265 float-to-integer conversion, round. */
5268 {
5274 /* The following calculations depend on proper rounding to even
5275 of each arithmetic operation. In order to prevent excess
5276 precision from spoiling this property, use the widest hardware
5277 floating-point type.
5279 FIXME: For maximum efficiency, this should only be done for machines
5280 and types where intermediates may have extra precision. */
5283 /* FIXME: Should not have padding in the first place */
5288 /* Compute the exact value calc_type'Pred (0.5) at compile time. */
5292 half_minus_pred_half);
5295 /* If the input is strictly negative, subtract this value
5296 and otherwise add it from the input. For 0.5, the result
5297 is exactly between 1.0 and the machine number preceding 1.0
5298 (for calc_type). Since the last bit of 1.0 is even, this 0.5
5299 will round to 1.0, while all other number with an absolute
5300 value less than 0.5 round to 0.0. For larger numbers exactly
5301 halfway between integers, rounding will always be correct as
5302 the true mathematical result will be closer to the higher
5303 integer compared to the lower one. So, this constant works
5304 for all floating-point numbers.
5306 The reason to use the same constant with subtract/add instead
5307 of a positive and negative constant is to allow the comparison
5308 to be scheduled in parallel with retrieval of the constant and
5309 conversion of the input to the calc_type (if necessary).
5310 */
5317 gnu_add_pred_half
5319 gnu_subtract_pred_half
5323 }
5329 else
5332 /* Finally, do the range check if requested. Note that if the
5333 result type is a modular type, the range check is actually
5334 an overflow check. */
5342 }
5343 \f
5344 /* Return 1 if GNU_EXPR can be directly addressed. This is the case unless
5345 it is an expression involving computation or if it involves a bitfield
5346 reference. This returns the same as gnat_mark_addressable in most
5347 cases. */
5349 static bool
5351 {
5353 {
5358 /* All DECLs are addressable: if they are in a register, we can force
5359 them to memory. */
5371 && !(STRICT_ALIGNMENT
5385 {
5386 /* This is addressable if we can avoid a copy. */
5400 }
5404 }
5405 }
5406 \f
5407 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
5408 a separate Freeze node exists, delay the bulk of the processing. Otherwise
5409 make a GCC type for GNAT_ENTITY and set up the correspondence. */
5411 void
5413 {
5414 tree gnu_old
5416 tree gnu_new;
5418 /* If we are to delay elaboration of this type, just do any
5419 elaborations needed for expressions within the declaration and
5420 make a dummy type entry for this node and its Full_View (if
5421 any) in case something points to it. Don't do this if it
5422 has already been done (the only way that can happen is if
5423 the private completion is also delayed). */
5429 {
5433 {
5442 }
5445 }
5447 /* If we saved away a dummy type for this node it means that this
5448 made the type that corresponds to the full type of an incomplete
5449 type. Clear that type for now and then update the type in the
5450 pointers. */
5452 {
5455 {
5456 /* If this was a withed access type, this is not an error
5457 and merely indicates we've already elaborated the type
5458 already. */
5461 }
5464 }
5466 /* Now fully elaborate the type. */
5470 /* If we have an old type and we've made pointers to this type,
5471 update those pointers. */
5476 /* If this is a record type corresponding to a task or protected type
5477 that is a completion of an incomplete type, perform a similar update
5478 on the type. */
5479 /* ??? Including protected types here is a guess. */
5484 {
5485 tree gnu_task_old
5495 }
5496 }
5497 \f
5498 /* GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate.
5499 GNU_TYPE is the GCC type of the corresponding record.
5501 Return a CONSTRUCTOR to build the record. */
5503 static tree
5505 {
5508 /* We test for GNU_FIELD being empty in the case where a variant
5509 was the last thing since we don't take things off GNAT_ASSOC in
5510 that case. We check GNAT_ASSOC in case we have a variant, but it
5511 has no fields. */
5515 {
5520 /* The expander is supposed to put a single component selector name
5521 in every record component association */
5524 /* Ignore fields that have Corresponding_Discriminants since we'll
5525 be setting that field in the parent. */
5530 /* Before assigning a value in an aggregate make sure range checks
5531 are done if required. Then convert to the type of the field. */
5537 /* Add the field and expression to the list. */
5539 }
5543 #ifdef ENABLE_CHECKING
5544 {
5545 tree gnu_field;
5547 /* Verify every enty in GNU_LIST was used. */
5550 }
5551 #endif
5554 }
5556 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
5557 is the first element of an array aggregate. It may itself be an
5558 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
5559 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
5560 of the array component. It is needed for range checking. */
5562 static tree
5564 Entity_Id gnat_component_type)
5565 {
5568 tree gnu_expr;
5571 {
5572 /* If the expression is itself an array aggregate then first build the
5573 innermost constructor if it is part of our array (multi-dimensional
5574 case). */
5581 gnat_component_type);
5582 else
5583 {
5586 /* before assigning the element to the array make sure it is
5587 in range */
5590 }
5592 gnu_expr_list
5594 gnu_expr_list);
5597 }
5600 }
5601 \f
5602 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
5603 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
5604 of the associations that are from RECORD_TYPE. If we see an internal
5605 record, make a recursive call to fill it in as well. */
5607 static tree
5609 {
5614 {
5617 /* _Parent is an internal field, but may have values in the aggregate,
5618 so check for values first. */
5620 {
5623 }
5626 {
5631 }
5632 else
5633 /* If we have a record subtype, the names will match, but not the
5634 actual FIELD_DECLs. */
5637 {
5640 }
5646 }
5649 }
5650 \f
5651 /* EXP is to be treated as an array or record. Handle the cases when it is
5652 an access object and perform the required dereferences. */
5654 static tree
5656 {
5657 /* If the type is a pointer, dereference it. */
5662 /* If we got a padded type, remove it too. */
5668 }
5669 \f
5670 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
5672 tree
5674 {
5677 /* If this has no side effects, we don't need to do anything. */
5681 /* If it is a conversion, protect what's inside the conversion.
5682 Similarly, if we're indirectly referencing something, we only
5683 actually need to protect the address since the data itself can't
5684 change in these situations. */
5693 /* If EXP is a fat pointer or something that can be placed into a register,
5694 just make a SAVE_EXPR. */
5698 /* Otherwise, dereference, protect the address, and re-reference. */
5699 else
5700 return
5704 exp)));
5705 }
5706 \f
5707 /* This is equivalent to stabilize_reference in GCC's tree.c, but we know
5708 how to handle our new nodes and we take an extra argument that says
5709 whether to force evaluation of everything. */
5711 tree
5713 {
5716 tree result;
5719 {
5723 /* No action is needed in this case. */
5735 result
5744 force));
5750 force),
5758 force),
5760 force));
5768 force),
5775 force),
5777 force));
5780 /* If arg isn't a kind of lvalue we recognize, make no change.
5781 Caller should recognize the error for an invalid lvalue. */
5787 }
5791 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS attached to the initial
5792 expression may not be sustained across some paths, such as the way via
5793 build1 for INDIRECT_REF. We re-populate those flags here for the general
5794 case, which is consistent with the GCC version of this routine.
5796 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
5797 paths introduce side effects where there was none initially (e.g. calls
5798 to save_expr), and we also want to keep track of that. */
5804 }
5806 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
5807 arg to force a SAVE_EXPR for everything. */
5809 static tree
5811 {
5814 tree result;
5816 /* We cannot ignore const expressions because it might be a reference
5817 to a const array but whose index contains side-effects. But we can
5818 ignore things that are actual constant or that already have been
5819 handled by this function. */
5825 {
5833 /* If this is a COMPONENT_REF of a fat pointer, save the entire
5834 fat pointer. This may be more efficient, but will also allow
5835 us to more easily find the match for the PLACEHOLDER_EXPR. */
5840 force),
5844 else
5849 /* Constants need no processing. In fact, we should never reach
5850 here. */
5854 /* Recursively stabilize each operand. */
5858 force));
5862 /* Recursively stabilize each operand. */
5865 force));
5870 }
5877 }
5879 /* Build a global constructor or destructor function. METHOD_TYPE gives
5880 the type of the function and CDTORS points to the list of constructor
5881 or destructor functions to be invoked. FIXME: Migrate into cgraph. */
5883 static void
5885 {
5889 {
5894 NULL_TREE);
5896 }
5899 }
5900 \f
5903 /* Convert Sloc into *LOCUS (a location_t). Return true if this Sloc
5904 corresponds to a source code location and false if it doesn't. In the
5905 latter case, we don't update *LOCUS. We also set the Gigi global variable
5906 REF_FILENAME to the reference file name as given by sinput (i.e no
5907 directory). */
5909 bool
5911 {
5912 /* If node not from source code, ignore. */
5916 /* Use the identifier table to make a hashed, permanent copy of the filename,
5917 since the name table gets reallocated after Gigi returns but before all
5918 the debugging information is output. The __gnat_to_canonical_file_spec
5919 call translates filenames from pragmas Source_Reference that contain host
5920 style syntax not understood by gdb. */
5921 locus->file
5922 = IDENTIFIER_POINTER
5923 (get_identifier
5924 (__gnat_to_canonical_file_spec
5929 ref_filename
5930 = IDENTIFIER_POINTER
5931 (get_identifier
5935 }
5937 /* Similar to annotate_with_locus, but start with the Sloc of GNAT_NODE and
5938 don't do anything if it doesn't correspond to a source location. */
5940 static void
5942 {
5943 location_t locus;
5949 }
5950 \f
5951 /* Post an error message. MSG is the error message, properly annotated.
5952 NODE is the node at which to post the error and the node to use for the
5953 "&" substitution. */
5955 void
5957 {
5958 String_Template temp;
5959 Fat_Pointer fp;
5965 }
5967 /* Similar, but NODE is the node at which to post the error and ENT
5968 is the node to use for the "&" substitution. */
5970 void
5972 {
5973 String_Template temp;
5974 Fat_Pointer fp;
5980 }
5982 /* Similar, but NODE is the node at which to post the error, ENT is the node
5983 to use for the "&" substitution, and N is the number to use for the ^. */
5985 void
5987 {
5988 String_Template temp;
5989 Fat_Pointer fp;
5997 }
5998 \f
5999 /* Similar to post_error_ne_num, but T is a GCC tree representing the
6000 number to write. If the tree represents a constant that fits within
6001 a host integer, the text inside curly brackets in MSG will be output
6002 (presumably including a '^'). Otherwise that text will not be output
6003 and the text inside square brackets will be output instead. */
6005 void
6007 {
6010 Fat_Pointer fp;
6018 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
6019 &&
6020 compare_tree_int
6022 #endif
6023 )
6024 {
6027 }
6028 else
6032 {
6038 ;
6039 else
6041 }
6048 }
6050 /* Similar to post_error_ne_tree, except that NUM is a second
6051 integer to write in the message. */
6053 void
6055 Node_Id node,
6056 Entity_Id ent,
6057 tree t,
6059 {
6062 }
6063 \f
6064 /* Initialize the table that maps GNAT codes to GCC codes for simple
6065 binary and unary operations. */
6067 void
6069 {
6095 }