| blob | 30c0fb5dc27b8c4b427b20aa389a0706e13e7931 |
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * T R A N S *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2006, 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 ****************************************************************************/
60 /* Let code below know whether we are targetting VMS without need of
61 intrusive preprocessor directives. */
62 #ifndef TARGET_ABI_OPEN_VMS
63 #define TARGET_ABI_OPEN_VMS 0
64 #endif
77 /* Current filename without path. */
80 /* If true, then gigi is being called on an analyzed but unexpanded
81 tree, and the only purpose of the call is to properly annotate
82 types with representation information. */
85 /* A structure used to gather together information about a statement group.
86 We use this to gather related statements, for example the "then" part
87 of a IF. In the case where it represents a lexical scope, we may also
88 have a BLOCK node corresponding to it and/or cleanups. */
95 };
99 /* List of unused struct stmt_group nodes. */
102 /* A structure used to record information on elaboration procedures
103 we've made and need to process.
105 ??? gnat_node should be Node_Id, but gengtype gets confused. */
111 };
115 /* Free list of TREE_LIST nodes used for stacks. */
118 /* List of TREE_LIST nodes representing a stack of exception pointer
119 variables. TREE_VALUE is the VAR_DECL that stores the address of
120 the raised exception. Nonzero means we are in an exception
121 handler. Not used in the zero-cost case. */
124 /* List of TREE_LIST nodes used to store the current elaboration procedure
125 decl. TREE_VALUE is the decl. */
128 /* Variable that stores a list of labels to be used as a goto target instead of
129 a return in some functions. See processing for N_Subprogram_Body. */
132 /* List of TREE_LIST nodes representing a stack of LOOP_STMT nodes.
133 TREE_VALUE of each entry is the label of the corresponding LOOP_STMT. */
136 /* List of TREE_LIST nodes representing labels for switch statements.
137 TREE_VALUE of each entry is the label at the end of the switch. */
140 /* Map GNAT tree codes to GCC tree codes for simple expressions. */
143 /* Current node being treated, in case abort called. */
144 Node_Id error_gnat_node;
176 \f
177 /* This is the main program of the back-end. It sets up all the table
178 structures and then generates code. */
180 void
188 Int gigi_operating_mode)
189 {
190 tree gnu_standard_long_long_float;
191 tree gnu_standard_exception_type;
211 /* If we are just annotating types, give VOID_TYPE zero sizes to avoid
212 errors. */
214 {
217 }
219 /* Save the type we made for integer as the type for Standard.Integer.
220 Then make the rest of the standard types. Note that some of these
221 may be subtypes. */
227 gnu_standard_long_long_float
229 gnu_standard_exception_type
234 /* Process any Pragma Ident for the main unit. */
235 #ifdef ASM_OUTPUT_IDENT
237 ASM_OUTPUT_IDENT
240 #endif
242 /* If we are using the GCC exception mechanism, let GCC know. */
249 /* Now see if we have any elaboration procedures to deal with. */
251 {
253 tree gnu_stmts;
255 /* Mark everything we have as not visited. */
258 /* Set the current function to be the elaboration procedure and gimplify
259 what we have. */
263 /* We should have a BIND_EXPR, but it may or may not have any statements
264 in it. If it doesn't have any, we have nothing to do. */
269 /* If there are no statements, there is no elaboration code. */
272 else
273 {
274 /* Otherwise, compile the function. Note that we'll be gimplifying
275 it twice, but that's fine for the nodes we use. */
278 }
279 }
280 }
281 \f
282 /* Perform initializations for this module. */
284 void
286 {
287 /* Initialize ourselves. */
291 /* Enable GNAT stack checking method if needed */
294 }
295 \f
296 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier,
297 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
298 where we should place the result type. */
300 static tree
302 {
303 tree gnu_result_type;
304 tree gnu_result;
307 /* If the Etype of this node does not equal the Etype of the Entity,
308 something is wrong with the entity map, probably in generic
309 instantiation. However, this does not apply to types. Since we sometime
310 have strange Ekind's, just do this test for objects. Also, if the Etype of
311 the Entity is private, the Etype of the N_Identifier is allowed to be the
312 full type and also we consider a packed array type to be the same as the
313 original type. Similarly, a class-wide type is equivalent to a subtype of
314 itself. Finally, if the types are Itypes, one may be a copy of the other,
315 which is also legal. */
338 /* If this is a reference to a deferred constant whose partial view is an
339 unconstrained private type, the proper type is on the full view of the
340 constant, not on the full view of the type, which may be unconstrained.
342 This may be a reference to a type, for example in the prefix of the
343 attribute Position, generated for dispatching code (see Make_DT in
344 exp_disp,adb). In that case we need the type itself, not is parent,
345 in particular if it is a derived type */
350 {
354 }
355 else
356 {
357 /* Expand the type of this identifier first, in case it is an enumeral
358 literal, which only get made when the type is expanded. There is no
359 order-of-elaboration issue here. We want to use the Actual_Subtype if
360 it has already been elaborated, otherwise the Etype. Avoid using
361 Actual_Subtype for packed arrays to simplify things. */
369 else
373 }
377 /* If we are in an exception handler, force this variable into memory to
378 ensure optimization does not remove stores that appear redundant but are
379 actually needed in case an exception occurs.
381 ??? Note that we need not do this if the variable is declared within the
382 handler, only if it is referenced in the handler and declared in an
383 enclosing block, but we have no way of testing that right now.
385 ??? Also, for now all we can do is make it volatile. But we only
386 do this for SJLJ. */
391 /* Some objects (such as parameters passed by reference, globals of
392 variable size, and renamed objects) actually represent the address
393 of the object. In that case, we must do the dereference. Likewise,
394 deal with parameters to foreign convention subprograms. Call fold
395 here since GNU_RESULT may be a CONST_DECL. */
400 {
402 tree renamed_obj;
406 gnu_result
409 gnu_result));
411 /* If it's a renaming pointer and we are at the right binding level,
412 we can reference the renamed object directly, since the renamed
413 expression has been protected against multiple evaluations. */
419 else
424 }
426 /* The GNAT tree has the type of a function as the type of its result. Also
427 use the type of the result if the Etype is a subtype which is nominally
428 unconstrained. But remove any padding from the resulting type. */
431 {
436 }
438 /* We always want to return the underlying INTEGER_CST for an enumeration
439 literal to avoid the need to call fold in lots of places. But don't do
440 this is the parent will be taking the address of this object. */
442 {
455 {
457 /* ??? The mark/unmark mechanism implemented in Gigi to prevent tree
458 sharing between global level and subprogram level doesn't apply
459 to elaboration routines. As a result, the DECL_INITIAL tree may
460 be shared between the static initializer of a global object and
461 the elaboration routine, thus wreaking havoc if a local temporary
462 is created in place during gimplification of the latter and the
463 former is emitted afterwards. Manually unshare for now. */
466 }
467 }
471 }
472 \f
473 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return
474 any statements we generate. */
476 static tree
478 {
479 Node_Id gnat_temp;
482 /* Check for (and ignore) unrecognized pragma and do nothing if we are just
483 annotating types. */
488 {
490 /* Do nothing at top level: all such variables are already viewable. */
497 {
506 }
512 {
525 }
532 }
535 }
536 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Attribute,
537 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
538 where we should place the result type. ATTRIBUTE is the attribute ID. */
540 static tree
542 {
544 tree gnu_result_type;
545 tree gnu_expr;
550 /* If the input is a NULL_EXPR, make a new one. */
552 {
556 }
559 {
562 /* These are just conversions until since representation clauses for
563 enumerations are handled in the front end. */
564 {
571 }
576 /* These just add or subject the constant 1. Representation clauses for
577 enumerations are handled in the front-end. */
582 {
584 gnu_expr
585 = emit_check
587 gnu_expr,
588 attribute == Attr_Pred
592 }
594 gnu_result
603 /* Conversions don't change something's address but can cause us to miss
604 the COMPONENT_REF case below, so strip them off. */
608 /* If we are taking 'Address of an unconstrained object, this is the
609 pointer to the underlying array. */
613 /* ... fall through ... */
619 gnu_result
626 /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we
627 don't try to build a trampoline. */
629 {
638 }
642 {
643 tree gnu_obj_type;
648 /* If this is an unconstrained array, we know the object must have been
649 allocated with the template in front of the object. So compute the
650 template address.*/
652 gnu_ptr
654 (TYPE_OBJECT_RECORD_TYPE
656 gnu_ptr);
661 {
664 tree gnu_byte_offset
671 }
674 }
683 /* Remove NOPS from gnu_expr and conversions from gnu_prefix.
684 We only use GNU_EXPR to see if a COMPONENT_REF was involved. */
687 ;
693 /* Replace an unconstrained array type with the type of the underlying
694 array. We can't do this with a call to maybe_unconstrained_array
695 since we may have a TYPE_DECL. For 'Max_Size_In_Storage_Elements,
696 use the record type that will be used to allocate the object and its
697 template. */
699 {
703 }
705 /* If we're looking for the size of a field, return the field size.
706 Otherwise, if the prefix is an object, or if 'Object_Size or
707 'Max_Size_In_Storage_Elements has been specified, the result is the
708 GCC size of the type. Otherwise, the result is the RM_Size of the
709 type. */
715 {
716 /* If this is a padded type, the GCC size isn't relevant to the
717 programmer. Normally, what we want is the RM_Size, which was set
718 from the specified size, but if it was not set, we want the size
719 of the relevant field. Using the MAX of those two produces the
720 right result in all case. Don't use the size of the field if it's
721 a self-referential type, since that's never what's wanted. */
725 {
729 gnu_result
732 }
734 {
740 {
744 }
747 }
748 else
750 }
751 else
756 /* Deal with a self-referential size by returning the maximum size for a
757 type and by qualifying the size with the object for 'Size of an
758 object. */
760 {
763 else
765 }
767 /* If the type contains a template, subtract its size. */
775 /* Always perform division using unsigned arithmetic as the size cannot
776 be negative, but may be an overflowed positive value. This provides
777 correct results for sizes up to 512 MB.
779 ??? Size should be calculated in storage elements directly. */
800 else
810 {
817 else
818 gnu_result
819 = build_binary_op
821 build_binary_op
833 }
835 /* ... fall through ... */
838 {
843 /* Make sure any implicit dereference gets done. */
851 {
853 tree gnu_type_temp;
859 ;
862 }
869 gnu_result
872 gnu_result
874 else
875 /* 'Length or 'Range_Length. */
876 {
877 tree gnu_compute_type
881 gnu_result
882 = build_binary_op
884 build_binary_op
886 build_binary_op
889 TYPE_MAX_VALUE
892 TYPE_MIN_VALUE
896 }
898 /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are
899 handling. Note that these attributes could not have been used on
900 an unconstrained array type. */
902 gnu_prefix);
904 }
911 {
912 HOST_WIDE_INT bitsize;
913 HOST_WIDE_INT bitpos;
914 tree gnu_offset;
915 tree gnu_field_bitpos;
916 tree gnu_field_offset;
917 tree gnu_inner;
925 /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF,
926 the result is 0. Don't allow 'Bit on a bare component, though. */
930 {
933 }
935 else
944 {
952 {
953 gnu_field_bitpos
956 gnu_field_offset
959 }
960 }
962 {
965 }
966 else
967 {
970 }
973 {
988 bitsize_one_node);
994 }
996 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
997 we are handling. */
1000 }
1004 {
1012 }
1040 /* Note this size cannot be self-referential. */
1047 /* This is just a zero cast to the pointer type for
1048 our prefix and dereferenced. */
1050 gnu_result
1053 integer_zero_node));
1058 {
1065 {
1070 ;
1071 }
1079 && (DECL_BY_COMPONENT_PTR_P
1083 }
1087 /* Say we have an unimplemented attribute. Then set the value to be
1088 returned to be a zero and hope that's something we can convert to the
1089 type of this attribute. */
1094 }
1096 /* If this is an attribute where the prefix was unused, force a use of it if
1097 it has a side-effect. But don't do it if the prefix is just an entity
1098 name. However, if an access check is needed, we must do it. See second
1099 example in AARM 11.6(5.e). */
1107 }
1108 \f
1109 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement,
1110 to a GCC tree, which is returned. */
1112 static tree
1114 {
1115 tree gnu_result;
1116 tree gnu_expr;
1117 Node_Id gnat_when;
1122 /* The range of values in a case statement is determined by the rules in
1123 RM 5.4(7-9). In almost all cases, this range is represented by the Etype
1124 of the expression. One exception arises in the case of a simple name that
1125 is parenthesized. This still has the Etype of the name, but since it is
1126 not a name, para 7 does not apply, and we need to go to the base type.
1127 This is the only case where parenthesization affects the dynamic
1128 semantics (i.e. the range of possible values at runtime that is covered
1129 by the others alternative.
1131 Another exception is if the subtype of the expression is non-static. In
1132 that case, we also have to use the base type. */
1138 /* We build a SWITCH_EXPR that contains the code with interspersed
1139 CASE_LABEL_EXPRs for each label. */
1146 {
1147 Node_Id gnat_choice;
1149 /* First compile all the different case choices for the current WHEN
1150 alternative. */
1153 {
1157 {
1172 /* This represents either a subtype range or a static value of
1173 some kind; Ekind says which. If a static value, fall through
1174 to the next case. */
1176 {
1182 }
1184 /* ... fall through ... */
1196 }
1201 gnat_choice);
1202 }
1204 /* Push a binding level here in case variables are declared since we want
1205 them to be local to this set of statements instead of the block
1206 containing the Case statement. */
1210 }
1212 /* Now emit a definition of the label all the cases branched to. */
1220 }
1221 \f
1222 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement,
1223 to a GCC tree, which is returned. */
1225 static tree
1227 {
1228 /* ??? It would be nice to use "build" here, but there's no build5. */
1234 tree gnu_result;
1241 /* Save the end label of this LOOP_STMT in a stack so that the corresponding
1242 N_Exit_Statement can find it. */
1246 /* Set the condition that under which the loop should continue.
1247 For "LOOP .... END LOOP;" the condition is always true. */
1249 ;
1250 /* The case "WHILE condition LOOP ..... END LOOP;" */
1254 else
1255 {
1256 /* We have an iteration scheme. */
1271 /* We know the loop variable will not overflow if GNU_LAST is a constant
1272 and is not equal to GNU_LIMIT. If it might overflow, we have to move
1273 the limit test to the end of the loop. In that case, we have to test
1274 for an empty loop outside the loop. */
1278 {
1279 gnu_cond_expr
1285 }
1287 /* Open a new nesting level that will surround the loop to declare the
1288 loop index variable. */
1292 /* Declare the loop index and set it to its initial value. */
1297 /* The loop variable might be a padded type, so use `convert' to get a
1298 reference to the inner variable if so. */
1301 /* Set either the top or bottom exit condition as appropriate depending
1302 on whether or not we know an overflow cannot occur. */
1307 else
1316 gnu_loop_var,
1318 integer_one_node));
1320 gnat_iter_scheme);
1321 }
1323 /* If the loop was named, have the name point to this loop. In this case,
1324 the association is not a ..._DECL node, but the end label from this
1325 LOOP_STMT. */
1330 /* Make the loop body into its own block, so any allocated storage will be
1331 released every iteration. This is needed for stack allocation. */
1335 /* If we declared a variable, then we are in a statement group for that
1336 declaration. Add the LOOP_STMT to it and make that the "loop". */
1338 {
1342 }
1344 /* If we have an outer COND_EXPR, that's our result and this loop is its
1345 "true" statement. Otherwise, the result is the LOOP_STMT. */
1347 {
1351 }
1352 else
1358 }
1359 \f
1360 /* Emit statements to establish __gnat_handle_vms_condition as a VMS condition
1361 handler for the current function. */
1363 /* This is implemented by issuing a call to the appropriate VMS specific
1364 builtin. To avoid having VMS specific sections in the global gigi decls
1365 array, we maintain the decls of interest here. We can't declare them
1366 inside the function because we must mark them never to be GC'd, which we
1367 can only do at the global level. */
1372 static void
1374 {
1375 tree establish_stmt;
1377 /* Elaborate the required decls on the first call. Check on the decl for
1378 the gnat condition handler to decide, as this is one we create so we are
1379 sure that it will be non null on subsequent calls. The builtin decl is
1380 looked up so remains null on targets where it is not implemented yet. */
1382 {
1383 vms_builtin_establish_handler_decl
1384 = builtin_decl_for
1387 gnat_vms_condition_handler_decl
1389 NULL_TREE,
1391 ptr_void_type_node,
1392 ptr_void_type_node,
1393 NULL_TREE),
1395 }
1397 /* Do nothing if the establish builtin is not available, which might happen
1398 on targets where the facility is not implemented. */
1402 establish_stmt
1404 build_unary_op
1406 gnat_vms_condition_handler_decl));
1409 }
1410 \f
1411 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We
1412 don't return anything. */
1414 static void
1416 {
1417 /* Save debug output mode in case it is reset. */
1420 /* Defining identifier of a parameter to the subprogram. */
1421 Entity_Id gnat_param;
1422 /* The defining identifier for the subprogram body. Note that if a
1423 specification has appeared before for this body, then the identifier
1424 occurring in that specification will also be a defining identifier and all
1425 the calls to this subprogram will point to that specification. */
1426 Entity_Id gnat_subprog_id
1429 /* The FUNCTION_DECL node corresponding to the subprogram spec. */
1430 tree gnu_subprog_decl;
1431 /* The FUNCTION_TYPE node corresponding to the subprogram spec. */
1432 tree gnu_subprog_type;
1433 tree gnu_cico_list;
1434 tree gnu_result;
1436 /* If this is a generic object or if it has been eliminated,
1437 ignore it. */
1443 /* If debug information is suppressed for the subprogram, turn debug
1444 mode off for the duration of processing. */
1446 {
1449 }
1451 /* If this subprogram acts as its own spec, define it. Otherwise, just get
1452 the already-elaborated tree node. However, if this subprogram had its
1453 elaboration deferred, we will already have made a tree node for it. So
1454 treat it as not being defined in that case. Such a subprogram cannot
1455 have an address clause or a freeze node, so this test is safe, though it
1456 does disable some otherwise-useful error checking. */
1457 gnu_subprog_decl
1464 /* Set the line number in the decl to correspond to that of the body so that
1465 the line number notes are written
1466 correctly. */
1472 /* If there are OUT parameters, we need to ensure that the return statement
1473 properly copies them out. We do this by making a new block and converting
1474 any inner return into a goto to a label at the end of the block. */
1478 /* Get a tree corresponding to the code for the subprogram. */
1482 /* See if there are any parameters for which we don't yet have GCC entities.
1483 These must be for OUT parameters for which we will be making VAR_DECL
1484 nodes here. Fill them in to TYPE_CI_CO_LIST, which must contain the empty
1485 entry as well. We can match up the entries because TYPE_CI_CO_LIST is in
1486 the order of the parameters. */
1491 {
1492 /* Skip any entries that have been already filled in; they must
1493 correspond to IN OUT parameters. */
1496 ;
1498 /* Do any needed references for padded types. */
1502 }
1505 /* On VMS, establish our condition handler to possibly turn a condition into
1506 the corresponding exception if the subprogram has a foreign convention or
1507 is exported.
1509 To ensure proper execution of local finalizations on condition instances,
1510 we must turn a condition into the corresponding exception even if there
1511 is no applicable Ada handler, and need at least one condition handler per
1512 possible call chain involving GNAT code. OTOH, establishing the handler
1513 has a cost so we want to mimize the number of subprograms into which this
1514 happens. The foreign or exported condition is expected to satisfy all
1515 the constraints. */
1522 /* Generate the code of the subprogram itself. A return statement will be
1523 present and any OUT parameters will be handled there. */
1528 /* If we made a special return label, we need to make a block that contains
1529 the definition of that label and the copying to the return value. That
1530 block first contains the function, then the label and copy statement. */
1532 {
1533 tree gnu_retval;
1544 else
1546 gnu_cico_list);
1551 add_stmt_with_node
1553 gnat_node);
1556 }
1560 /* Initialize the information node for the function and set the
1561 end location. */
1563 Sloc_to_locus
1571 /* Disconnect the trees for parameters that we made variables for from the
1572 GNAT entities since these are unusable after we end the function. */
1582 }
1583 \f
1584 /* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call
1585 or an N_Procedure_Call_Statement, to a GCC tree, which is returned.
1586 GNU_RESULT_TYPE_P is a pointer to where we should place the result type.
1587 If GNU_TARGET is non-null, this must be a function call and the result
1588 of the call is to be placed into that object. */
1590 static tree
1592 {
1593 tree gnu_result;
1594 /* The GCC node corresponding to the GNAT subprogram name. This can either
1595 be a FUNCTION_DECL node if we are dealing with a standard subprogram call,
1596 or an indirect reference expression (an INDIRECT_REF node) pointing to a
1597 subprogram. */
1599 /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */
1602 gnu_subprog_node);
1603 Entity_Id gnat_formal;
1604 Node_Id gnat_actual;
1609 tree gnu_subprog_call;
1612 {
1619 }
1623 /* If we are calling a stubbed function, make this into a raise of
1624 Program_Error. Elaborate all our args first. */
1627 {
1633 {
1634 tree call_expr
1638 {
1641 }
1642 else
1644 }
1645 }
1647 /* If we are calling by supplying a pointer to a target, set up that
1648 pointer as the first argument. Use GNU_TARGET if one was passed;
1649 otherwise, make a target by building a variable of the maximum size
1650 of the type. */
1652 {
1653 tree gnu_real_ret_type
1657 {
1658 tree gnu_obj_type
1664 /* ??? We may be about to create a static temporary if we happen to
1665 be at the global binding level. That's a regression from what
1666 the 3.x back-end would generate in the same situation, but we
1667 don't have a mechanism in Gigi for creating automatic variables
1668 in the elaboration routines. */
1669 gnu_target
1672 gnat_node);
1673 }
1675 gnu_actual_list
1679 gnu_target,
1681 NULL_TREE);
1683 }
1685 /* The only way we can be making a call via an access type is if Name is an
1686 explicit dereference. In that case, get the list of formal args from the
1687 type the access type is pointing to. Otherwise, get the formals from
1688 entity being called. */
1692 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
1694 else
1697 /* Create the list of the actual parameters as GCC expects it, namely a chain
1698 of TREE_LIST nodes in which the TREE_VALUE field of each node is a
1699 parameter-expression and the TREE_PURPOSE field is null. Skip OUT
1700 parameters not passed by reference and don't need to be copied in. */
1705 {
1706 tree gnu_formal
1710 /* We treat a conversion between aggregate types as if it is an
1711 unchecked conversion. */
1712 bool unchecked_convert_p
1716 Node_Id gnat_name = (unchecked_convert_p
1720 tree gnu_actual;
1722 /* If it's possible we may need to use this expression twice, make sure
1723 than any side-effects are handled via SAVE_EXPRs. Likewise if we need
1724 to force side-effects before the call.
1726 ??? This is more conservative than we need since we don't need to do
1727 this for pass-by-ref with no conversion. If we are passing a
1728 non-addressable Out or In Out parameter by reference, pass the address
1729 of a copy and set up to copy back out after the call. */
1731 {
1735 && gnu_formal
1740 {
1742 tree gnu_temp;
1744 /* For users of Starlet we issue a warning because the
1745 interface apparently assumes that by-ref parameters
1746 outlive the procedure invocation. The code still
1747 will not work as intended, but we cannot do much
1748 better since other low-level parts of the back-end
1749 would allocate temporaries at will because of the
1750 misalignment if we did not do so here. */
1753 {
1754 post_error
1756 gnat_actual);
1757 post_error_ne
1760 post_error_ne
1763 }
1765 /* Remove any unpadding on the actual and make a copy. But if
1766 the actual is a justified modular type, first convert
1767 to it. */
1771 && (TYPE_IS_PADDING_P
1780 /* Since we're going to take the address of the SAVE_EXPR, we
1781 don't want it to be marked as unchanging. So set
1782 TREE_ADDRESSABLE. */
1785 {
1788 }
1790 /* Set up to move the copy back to the original. */
1796 /* Account for next statement just below. */
1798 }
1799 }
1801 /* If this was a procedure call, we may not have removed any padding.
1802 So do it here for the part we will use as an input, if any. */
1808 gnu_actual);
1810 /* Unless this is an In parameter, we must remove any LJM building
1811 from GNU_NAME. */
1817 gnu_name);
1820 && !unchecked_convert_p
1824 /* Do any needed conversions. We need only check for unchecked
1825 conversion since normal conversions will be handled by just
1826 converting to the formal type. */
1828 {
1829 gnu_actual
1831 gnu_actual,
1836 /* One we've done the unchecked conversion, we still must ensure that
1837 the object is in range of the formal's type. */
1842 }
1844 /* We may have suppressed a conversion to the Etype of the actual since
1845 the parent is a procedure call. So add the conversion here. */
1847 gnu_actual);
1852 /* If we have not saved a GCC object for the formal, it means it is an
1853 OUT parameter not passed by reference and that does not need to be
1854 copied in. Otherwise, look at the PARM_DECL to see if it is passed by
1855 reference. */
1858 {
1860 {
1863 /* If we have a padded type, be sure we've removed padding. */
1868 gnu_actual);
1870 /* If we have the constructed subtype of an aliased object
1871 with an unconstrained nominal subtype, the type of the
1872 actual includes the template, although it is formally
1873 constrained. So we need to convert it back to the real
1874 constructed subtype to retrieve the constrained part
1875 and takes its address. */
1882 gnu_actual);
1883 }
1885 /* Otherwise, if we have a non-addressable COMPONENT_REF of a
1886 variable-size type see if it's doing a unpadding operation. If
1887 so, remove that operation since we have no way of allocating the
1888 required temporary. */
1898 /* The symmetry of the paths to the type of an entity is broken here
1899 since arguments don't know that they will be passed by ref. */
1902 }
1905 {
1912 {
1915 }
1917 /* Take the address of the object and convert to the proper pointer
1918 type. We'd like to actually compute the address of the beginning
1919 of the array using an ADDR_EXPR of an ARRAY_REF, but there's a
1920 possibility that the ARRAY_REF might return a constant and we'd be
1921 getting the wrong address. Neither approach is exactly correct,
1922 but this is the most likely to work in all cases. */
1925 gnu_actual));
1926 }
1929 {
1930 /* If arg is 'Null_Parameter, pass zero descriptor. */
1935 integer_zero_node);
1936 else
1939 gnat_formal));
1940 }
1941 else
1942 {
1951 /* If this is 'Null_Parameter, pass a zero even though we are
1952 dereferencing it. */
1957 BITS_PER_WORD))
1958 gnu_actual
1963 integer_zero_node),
1965 else
1967 }
1970 }
1974 NULL_TREE);
1976 /* If we return by passing a target, we emit the call and return the target
1977 as our result. */
1979 {
1981 *gnu_result_type_p
1984 }
1986 /* If it is a function call, the result is the call expression unless
1987 a target is specified, in which case we copy the result into the target
1988 and return the assignment statement. */
1990 {
1993 /* If the function returns an unconstrained array or by reference,
1994 we have to de-dereference the pointer. */
2002 else
2006 }
2008 /* If this is the case where the GNAT tree contains a procedure call
2009 but the Ada procedure has copy in copy out parameters, the special
2010 parameter passing mechanism must be used. */
2012 {
2013 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
2014 in copy out parameters. */
2019 {
2020 tree gnu_name;
2025 /* If any of the names had side-effects, ensure they are all
2026 evaluated before the call. */
2032 }
2036 else
2043 /* If we are dealing with a copy in copy out parameter, we must
2044 retrieve its value from the record returned in the call. */
2050 || (DECL_BY_DESCRIPTOR_P
2053 {
2054 /* Get the value to assign to this OUT or IN OUT parameter. It is
2055 either the result of the function if there is only a single such
2056 parameter or the appropriate field from the record returned. */
2057 tree gnu_result
2064 /* If the actual is a conversion, get the inner expression, which
2065 will be the real destination, and convert the result to the
2066 type of the actual parameter. */
2067 tree gnu_actual
2070 /* If the result is a padded type, remove the padding. */
2075 gnu_result);
2077 /* If the result is a type conversion, do it. */
2079 gnu_result
2080 = convert_with_check
2088 gnu_result,
2090 else
2091 {
2099 }
2107 }
2108 }
2109 else
2110 {
2113 }
2117 }
2118 \f
2119 /* Subroutine of gnat_to_gnu to translate gnat_node, an
2120 N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */
2122 static tree
2124 {
2127 /* If just annotating, ignore all EH and cleanups. */
2131 bool setjmp_longjmp
2137 tree gnu_result;
2138 tree gnu_expr;
2139 Node_Id gnat_temp;
2141 /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes
2142 and we have our own SJLJ mechanism. To call the GCC mechanism, we call
2143 add_cleanup, and when we leave the binding, end_stmt_group will create
2144 the TRY_FINALLY_EXPR.
2146 ??? The region level calls down there have been specifically put in place
2147 for a ZCX context and currently the order in which things are emitted
2148 (region/handlers) is different from the SJLJ case. Instead of putting
2149 other calls with different conditions at other places for the SJLJ case,
2150 it seems cleaner to reorder things for the SJLJ case and generalize the
2151 condition to make it not ZCX specific.
2153 If there are any exceptions or cleanup processing involved, we need an
2154 outer statement group (for Setjmp_Longjmp) and binding level. */
2156 {
2159 }
2161 /* If we are to call a function when exiting this block add a cleanup
2162 to the binding level we made above. */
2166 /* If using setjmp_longjmp, make the variables for the setjmp buffer and save
2167 area for address of previous buffer. Do this first since we need to have
2168 the setjmp buf known for any decls in this block. */
2170 {
2175 gnat_node);
2183 /* When we exit this block, restore the saved value. */
2185 }
2187 /* Now build the tree for the declarations and statements inside this block.
2188 If this is SJLJ, set our jmp_buf as the current buffer. */
2194 gnu_jmpbuf_decl)));
2200 /* Generate code for each statement in the block. */
2208 /* Now generate code for the two exception models, if either is relevant for
2209 this block. */
2211 {
2213 tree gnu_handler;
2215 /* Make a binding level for the exception handling declarations and code
2216 and set up gnu_except_ptr_stack for the handlers to use. */
2222 NULL_TREE,
2227 /* Generate code for each handler. The N_Exception_Handler case does the
2228 real work and returns a COND_EXPR for each handler, which we chain
2229 together here. */
2232 {
2235 /* If this is the first one, set it as the outer one. Otherwise,
2236 point the "else" part of the previous handler to us. Then point
2237 to our "else" part. */
2240 else
2244 }
2246 /* If none of the exception handlers did anything, re-raise but do not
2247 defer abortion. */
2254 else
2257 /* End the binding level dedicated to the exception handlers and get the
2258 whole statement group. */
2263 /* If the setjmp returns 1, we restore our incoming longjmp value and
2264 then check the handlers. */
2267 gnu_jmpsave_decl),
2268 gnat_node);
2272 /* This block is now "if (setjmp) ... <handlers> else <block>". */
2274 (build_call_1_expr
2277 gnu_jmpbuf_decl))),
2279 }
2281 {
2282 tree gnu_handlers;
2284 /* First make a block containing the handlers. */
2292 /* Now make the TRY_CATCH_EXPR for the block. */
2295 }
2296 else
2299 /* Now close our outer block, if we had to make one. */
2301 {
2305 }
2308 }
2309 \f
2310 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2311 to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp
2312 exception handling. */
2314 static tree
2316 {
2317 /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make
2318 an "if" statement to select the proper exceptions. For "Others", exclude
2319 exceptions where Handled_By_Others is nonzero unless the All_Others flag
2320 is set. For "Non-ada", accept an exception if "Lang" is 'V'. */
2323 Node_Id gnat_temp;
2327 {
2328 tree this_choice;
2331 {
2334 else
2335 this_choice
2336 = build_binary_op
2338 convert
2340 build_component_ref
2341 (build_unary_op
2346 integer_zero_node);
2347 }
2351 {
2353 tree gnu_expr;
2355 /* Exception may be a renaming. Recover original exception which is
2356 the one elaborated and registered. */
2362 this_choice
2363 = build_binary_op
2368 /* If this is the distinguished exception "Non_Ada_Error" (and we are
2369 in VMS mode), also allow a non-Ada exception (a VMS condition) t
2370 match. */
2372 {
2373 tree gnu_comp
2374 = build_component_ref
2379 this_choice
2380 = build_binary_op
2384 this_choice);
2385 }
2386 }
2387 else
2392 }
2395 }
2396 \f
2397 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2398 to a GCC tree, which is returned. This is the variant for ZCX. */
2400 static tree
2402 {
2404 tree gnu_expr;
2405 tree gnu_etype;
2406 tree gnu_current_exc_ptr;
2407 tree gnu_incoming_exc_ptr;
2408 Node_Id gnat_temp;
2410 /* We build a TREE_LIST of nodes representing what exception types this
2411 handler can catch, with special cases for others and all others cases.
2413 Each exception type is actually identified by a pointer to the exception
2414 id, or to a dummy object for "others" and "all others".
2416 Care should be taken to ensure that the control flow impact of "others"
2417 and "all others" is known to GCC. lang_eh_type_covers is doing the trick
2418 currently. */
2421 {
2423 {
2424 tree gnu_expr
2427 gnu_etype
2429 }
2432 {
2435 /* Exception may be a renaming. Recover original exception which is
2436 the one elaborated and registered. */
2443 /* The Non_Ada_Error case for VMS exceptions is handled
2444 by the personality routine. */
2445 }
2446 else
2449 /* The GCC interface expects NULL to be passed for catch all handlers, so
2450 it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype
2451 is integer_zero_node. It would not work, however, because GCC's
2452 notion of "catch all" is stronger than our notion of "others". Until
2453 we correctly use the cleanup interface as well, doing that would
2454 prevent the "all others" handlers from being seen, because nothing
2455 can be caught beyond a catch all from GCC's point of view. */
2457 }
2462 /* Expand a call to the begin_handler hook at the beginning of the handler,
2463 and arrange for a call to the end_handler hook to occur on every possible
2464 exit path.
2466 The hooks expect a pointer to the low level occurrence. This is required
2467 for our stack management scheme because a raise inside the handler pushes
2468 a new occurrence on top of the stack, which means that this top does not
2469 necessarily match the occurrence this handler was dealing with.
2471 The EXC_PTR_EXPR object references the exception occurrence being
2472 propagated. Upon handler entry, this is the exception for which the
2473 handler is triggered. This might not be the case upon handler exit,
2474 however, as we might have a new occurrence propagated by the handler's
2475 body, and the end_handler hook called as a cleanup in this context.
2477 We use a local variable to retrieve the incoming value at handler entry
2478 time, and reuse it to feed the end_handler hook's argument at exit. */
2483 gnat_node);
2486 gnu_incoming_exc_ptr),
2487 gnat_node);
2494 }
2495 \f
2496 /* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */
2498 static void
2500 {
2501 /* Make the decl for the elaboration procedure. */
2506 tree gnu_elab_proc_decl
2507 = create_subprog_decl
2511 gnat_unit_entity);
2521 /* For a body, first process the spec if there is one. */
2530 {
2537 }
2543 /* Process any pragmas and actions following the unit. */
2547 /* Save away what we've made so far and record this potential elaboration
2548 procedure. */
2558 /* Generate elaboration code for this unit, if necessary, and say whether
2559 we did or not. */
2562 /* Generate functions to call static constructors and destructors
2563 for targets that do not support .ctors/.dtors sections. These
2564 functions have magic names which are detected by collect2. */
2570 }
2571 \f
2572 /* This function is the driver of the GNAT to GCC tree transformation
2573 process. It is the entry point of the tree transformer. GNAT_NODE is the
2574 root of some GNAT tree. Return the root of the corresponding GCC tree.
2575 If this is an expression, return the GCC equivalent of the expression. If
2576 it is a statement, return the statement. In the case when called for a
2577 statement, it may also add statements to the current statement group, in
2578 which case anything it returns is to be interpreted as occurring after
2579 anything `it already added. */
2581 tree
2583 {
2587 tree gnu_expr;
2589 Node_Id gnat_temp;
2591 /* Save node number for error message and set location information. */
2599 /* If this node is a non-static subexpression and we are only
2600 annotating types, make this into a NULL_EXPR. */
2608 /* If this is a Statement and we are at top level, it must be part of the
2609 elaboration procedure, so mark us as being in that procedure and push our
2610 context.
2612 If we are in the elaboration procedure, check if we are violating a a
2613 No_Elaboration_Code restriction by having a statement there. */
2624 {
2626 {
2631 }
2633 /* Don't check for a possible No_Elaboration_Code restriction violation
2634 on N_Handled_Sequence_Of_Statements, as we want to signal an error on
2635 every nested real statement instead. This also avoids triggering
2636 spurious errors on dummy (empty) sequences created by the front-end
2637 for package bodies in some cases. */
2642 }
2645 {
2646 /********************************/
2647 /* Chapter 2: Lexical Elements: */
2648 /********************************/
2658 {
2659 tree gnu_type;
2661 /* Get the type of the result, looking inside any padding and
2662 justified modular types. Then get the value in that type. */
2671 /* If the result overflows (meaning it doesn't fit in its base type),
2672 abort. We would like to check that the value is within the range
2673 of the subtype, but that causes problems with subtypes whose usage
2674 will raise Constraint_Error and with biased representation, so
2675 we don't. */
2677 }
2681 /* If a Entity is present, it means that this was one of the
2682 literals in a user-defined character type. In that case,
2683 just return the value in the CONST_DECL. Otherwise, use the
2684 character code. In that case, the base type should be an
2685 INTEGER_TYPE, but we won't bother checking for that. */
2689 else
2690 gnu_result
2691 = force_fit_type
2692 (build_int_cst
2698 /* If this is of a fixed-point type, the value we want is the
2699 value of the corresponding integer. */
2701 {
2704 gnu_result_type);
2706 }
2708 /* We should never see a Vax_Float type literal, since the front end
2709 is supposed to transform these using appropriate conversions */
2713 else
2714 {
2719 /* If the real value is zero, so is the result. Otherwise,
2720 convert it to a machine number if it isn't already. That
2721 forces BASE to 0 or 2 and simplifies the rest of our logic. */
2724 else
2725 {
2727 ur_realval
2731 gnu_result
2734 /* If we have a base of zero, divide by the denominator.
2735 Otherwise, the base must be 2 and we scale the value, which
2736 we know can fit in the mantissa of the type (hence the use
2737 of that type above). */
2739 gnu_result
2742 gnu_result,
2744 gnu_result_type));
2745 else
2746 {
2747 REAL_VALUE_TYPE tmp;
2753 }
2754 }
2756 /* Now see if we need to negate the result. Do it this way to
2757 properly handle -0. */
2759 gnu_result
2761 gnu_result);
2762 }
2769 {
2775 /* Build the string with the characters in the literal. Note
2776 that Ada strings are 1-origin. */
2780 /* Put a null at the end of the string in case it's in a context
2781 where GCC will want to treat it as a C string. */
2786 /* Strings in GCC don't normally have types, but we want
2787 this to not be converted to the array type. */
2789 }
2790 else
2791 {
2792 /* Build a list consisting of each character, then make
2793 the aggregate. */
2801 {
2802 gnu_list
2807 gnu_list);
2811 }
2813 gnu_result
2815 }
2822 /**************************************/
2823 /* Chapter 3: Declarations and Types: */
2824 /**************************************/
2841 /* If we are just annotating types and this object has an unconstrained
2842 or task type, don't elaborate it. */
2853 && (!type_annotate_only
2855 {
2860 /* If this object has its elaboration delayed, we must force
2861 evaluation of GNU_EXPR right now and save it for when the object
2862 is frozen. */
2864 {
2867 gnu_expr
2872 else
2876 }
2877 }
2878 else
2891 /* Don't do anything if this renaming is handled by the front end or if
2892 we are just annotating types and this object has a composite or task
2893 type, don't elaborate it. We return the result in case it has any
2894 SAVE_EXPRs in it that need to be evaluated here. */
2896 && ! (type_annotate_only
2900 gnu_result
2903 else
2916 /* These are fully handled in the front end. */
2920 /*************************************/
2921 /* Chapter 4: Names and Expressions: */
2922 /*************************************/
2931 {
2933 tree gnu_type;
2941 /* If we got a padded type, remove it too. */
2944 gnu_array_object
2946 gnu_array_object);
2950 /* First compute the number of dimensions of the array, then
2951 fill the expression array, the order depending on whether
2952 this is a Convention_Fortran array or not. */
2957 ;
2966 else
2974 {
2980 gnu_expr
2981 = emit_index_check
2988 }
2989 }
2995 {
2996 tree gnu_type;
3002 /* Do any implicit dereferences of the prefix and do any needed
3003 range check. */
3008 {
3009 /* Get the bounds of the slice. */
3010 tree gnu_index_type
3016 /* Check to see that the minimum slice value is in range */
3017 gnu_expr_l
3018 = emit_index_check
3023 /* Check to see that the maximum slice value is in range */
3024 gnu_expr_h
3025 = emit_index_check
3030 /* Derive a good type to convert everything too */
3033 /* Build a compound expression that does the range checks */
3034 gnu_expr
3039 /* Build a conditional expression that returns the range checks
3040 expression if the slice range is not null (max >= min) or
3041 returns the min if the slice range is null */
3042 gnu_expr
3046 gnu_max_expr),
3048 gnu_min_expr)),
3050 }
3051 else
3056 }
3060 {
3064 tree gnu_field;
3068 {
3073 }
3077 /* For discriminant references in tagged types always substitute the
3078 corresponding discriminant as the actual selected component. */
3084 /* For discriminant references of untagged types always substitute the
3085 corresponding stored discriminant. */
3090 /* Handle extracting the real or imaginary part of a complex.
3091 The real part is the first field and the imaginary the last. */
3097 else
3098 {
3101 /* If there are discriminants, the prefix might be
3102 evaluated more than once, which is a problem if it has
3103 side-effects. */
3110 gnu_result
3114 }
3118 }
3122 {
3123 /* The attribute designator (like an enumeration value). */
3126 /* The Elab_Spec and Elab_Body attributes are special in that
3127 Prefix is a unit, not an object with a GCC equivalent. Similarly
3128 for Elaborated, since that variable isn't otherwise known. */
3132 attribute == Attr_Elab_Body
3135 gnat_node));
3138 }
3142 /* Like 'Access as far as we are concerned. */
3150 {
3151 tree gnu_aggr_type;
3153 /* ??? It is wrong to evaluate the type now, but there doesn't
3154 seem to be any other practical way of doing it. */
3158 gnu_aggr_type = gnu_result_type
3163 gnu_aggr_type
3171 gnu_result
3174 gnu_aggr_type);
3177 gnu_aggr_type,
3180 gnu_result
3181 = build_binary_op
3186 (Next
3188 else
3192 }
3202 /* Get the operand expression. */
3206 gnu_result
3218 /* If the result is a pointer type, see if we are improperly
3219 converting to a stricter alignment. */
3223 {
3229 post_error_ne_tree_2
3233 }
3241 {
3244 tree gnu_low;
3245 tree gnu_high;
3247 /* GNAT_RANGE is either an N_Range node or an identifier
3248 denoting a subtype. */
3250 {
3253 }
3256 {
3261 }
3262 else
3267 /* If LOW and HIGH are identical, perform an equality test.
3268 Otherwise, ensure that GNU_OBJECT is only evaluated once
3269 and perform a full range test. */
3273 else
3274 {
3276 gnu_result
3282 }
3286 }
3294 ? RDIV_EXPR
3301 /* These can either be operations on booleans or on modular types.
3302 Fall through for boolean types since that's the way GNU_CODES is
3303 set up. */
3305 Modular_Integer_Kind))
3306 {
3307 enum tree_code code
3318 }
3320 /* ... fall through ... */
3332 {
3334 tree gnu_type;
3340 /* If this is a comparison operator, convert any references to
3341 an unconstrained array value into a reference to the
3342 actual array. */
3344 {
3347 }
3349 /* If the result type is a private type, its full view may be a
3350 numeric subtype. The representation we need is that of its base
3351 type, given that it is the result of an arithmetic operation. */
3353 gnu_type = gnu_result_type
3356 /* If this is a shift whose count is not guaranteed to be correct,
3357 we need to adjust the shift count. */
3360 {
3362 tree gnu_max_shift
3370 gnu_rhs
3371 = build_binary_op
3374 gnu_count_type,
3375 gnu_max_shift,
3377 integer_one_node)),
3378 gnu_rhs);
3379 }
3381 /* For right shifts, the type says what kind of shift to do,
3382 so we may need to choose a different type. */
3391 {
3394 }
3398 /* If this is a logical shift with the shift count not verified,
3399 we must return zero if it is too large. We cannot compensate
3400 above in this case. */
3404 gnu_result
3405 = build_cond_expr
3408 gnu_rhs,
3412 gnu_result);
3413 }
3417 {
3420 tree gnu_false
3427 }
3436 /* This case can apply to a boolean or a modular type.
3437 Fall through for a boolean operand since GNU_CODES is set
3438 up to handle this. */
3440 {
3444 gnu_expr);
3446 }
3448 /* ... fall through ... */
3455 else
3464 {
3466 tree gnu_type;
3471 /* The Expression operand can either be an N_Identifier or
3472 Expanded_Name, which must represent a type, or a
3473 N_Qualified_Expression, which contains both the object type and an
3474 initial value for the object. */
3479 {
3480 Entity_Id gnat_desig_type
3492 {
3495 }
3496 else
3497 {
3503 }
3504 }
3505 else
3512 ignore_init_type);
3513 }
3516 /***************************/
3517 /* Chapter 5: Statements: */
3518 /***************************/
3530 /* Get the LHS and RHS of the statement and convert any reference to an
3531 unconstrained array into a reference to the underlying array.
3532 If we are not to do range checking and the RHS is an N_Function_Call,
3533 pass the LHS to the call function. */
3536 /* If the type has a size that overflows, convert this into raise of
3537 Storage_Error: execution shouldn't have gotten here anyway. */
3545 else
3546 {
3547 gnu_rhs
3550 /* If range check is needed, emit code to generate it */
3554 gnu_result
3556 }
3560 {
3563 /* Make the outer COND_EXPR. Avoid non-determinism. */
3572 /* Now make a COND_EXPR for each of the "else if" parts. Put each
3573 into the previous "else" part and point to where to put any
3574 outer "else". Also avoid non-determinism. */
3578 {
3588 }
3591 }
3615 gnu_result
3625 {
3626 /* The gnu function type of the subprogram currently processed. */
3628 /* The return value from the subprogram. */
3630 /* The place to put the return value. */
3631 tree gnu_lhs;
3633 /* If we are dealing with a "return;" from an Ada procedure with
3634 parameters passed by copy in copy out, we need to return a record
3635 containing the final values of these parameters. If the list
3636 contains only one entry, return just that entry.
3638 For a full description of the copy in copy out parameter mechanism,
3639 see the part of the gnat_to_gnu_entity routine dealing with the
3640 translation of subprograms.
3642 But if we have a return label defined, convert this into
3643 a branch to that label. */
3646 {
3650 }
3653 {
3657 else
3658 gnu_ret_val
3661 }
3663 /* If the Ada subprogram is a function, we just need to return the
3664 expression. If the subprogram returns an unconstrained
3665 array, we have to allocate a new version of the result and
3666 return it. If we return by reference, return a pointer. */
3669 {
3670 /* If the current function returns by target pointer and we
3671 are doing a call, pass that target to the call. */
3674 {
3675 gnu_lhs
3680 }
3681 else
3682 {
3686 /* The original return type was unconstrained so dereference
3687 the TARGET pointer in the actual return value's type. */
3688 gnu_lhs
3691 else
3694 /* Do not remove the padding from GNU_RET_VAL if the inner
3695 type is self-referential since we want to allocate the fixed
3696 size in that case. */
3700 && (TYPE_IS_PADDING_P
3702 && (CONTAINS_PLACEHOLDER_P
3708 gnu_ret_val
3712 {
3715 /* We have two cases: either the function returns with
3716 depressed stack or not. If not, we allocate on the
3717 secondary stack. If so, we allocate in the stack frame.
3718 if no copy is needed, the front end will set By_Ref,
3719 which we handle in the case above. */
3721 gnu_ret_val
3723 gnu_ret_val,
3726 else
3727 gnu_ret_val
3729 gnu_ret_val,
3734 }
3735 }
3736 }
3737 else
3738 /* If the Ada subprogram is a regular procedure, just return. */
3742 {
3748 }
3751 }
3759 /****************************/
3760 /* Chapter 6: Subprograms: */
3761 /****************************/
3764 /* Unless there is a freeze node, declare the subprogram. We consider
3765 this a "definition" even though we're not generating code for
3766 the subprogram because we will be making the corresponding GCC
3767 node here. */
3776 /* This subprogram doesn't exist for code generation purposes, but we
3777 have to elaborate the types of any parameters, unless they are
3778 imported types (nothing to generate in this case). */
3791 /* For a child unit identifier go up a level to get the
3792 specification. We get this when we try to find the spec of
3793 a child unit package that is the compilation unit being compiled. */
3807 /*************************/
3808 /* Chapter 7: Packages: */
3809 /*************************/
3825 /* If this is the body of a generic package - do nothing */
3827 {
3830 }
3841 /*********************************/
3842 /* Chapter 8: Visibility Rules: */
3843 /*********************************/
3847 /* Nothing to do here - but these may appear in list of declarations */
3851 /***********************/
3852 /* Chapter 9: Tasks: */
3853 /***********************/
3864 /***********************************************************/
3865 /* Chapter 10: Program Structure and Compilation Issues: */
3866 /***********************************************************/
3870 /* This is not called for the main unit, which is handled in function
3871 gigi above. */
3883 /* Simply process whatever unit is being inserted. */
3891 /***************************/
3892 /* Chapter 11: Exceptions: */
3893 /***************************/
3896 /* If there is an At_End procedure attached to this node, and the EH
3897 mechanism is SJLJ, we must have at least a corresponding At_End
3898 handler, unless the No_Exception_Handlers restriction is set. */
3913 else
3918 /*******************************/
3919 /* Chapter 12: Generic Units: */
3920 /*******************************/
3930 /* These nodes can appear on a declaration list but there is nothing to
3931 to be done with them. */
3935 /***************************************************/
3936 /* Chapter 13: Representation Clauses and */
3937 /* Implementation-Dependent Features: */
3938 /***************************************************/
3944 /* The only one we need deal with is for 'Address. For the others, SEM
3945 puts the information elsewhere. We need only deal with 'Address
3946 if the object has a Freeze_Node (which it never will currently). */
3951 /* Get the value to use as the address and save it as the
3952 equivalent for GNAT_TEMP. When the object is frozen,
3953 gnat_to_gnu_entity will do the right thing. */
3961 /* We do nothing with these. SEM puts the information elsewhere. */
3967 {
3973 /* First process inputs, then outputs, then clobbers. */
3976 {
3981 gnu_input_list
3984 }
3988 {
3993 gnu_output_list
3996 }
4000 gnu_clobber_list
4003 gnu_clobber_list);
4011 }
4012 else
4017 /***************************************************/
4018 /* Added Nodes */
4019 /***************************************************/
4037 {
4040 tree gnu_obj_type;
4042 tree gnu_obj_size;
4045 /* If this is a thin pointer, we must dereference it to create
4046 a fat pointer, then go back below to a thin pointer. The
4047 reason for this is that we need a fat pointer someplace in
4048 order to properly compute the size. */
4052 gnu_ptr));
4054 /* If this is an unconstrained array, we know the object must
4055 have been allocated with the template in front of the object.
4056 So pass the template address, but get the total size. Do this
4057 by converting to a thin pointer. */
4059 gnu_ptr
4061 (TYPE_OBJECT_RECORD_TYPE
4063 gnu_ptr);
4068 {
4069 gnu_actual_obj_type
4073 gnu_actual_obj_type
4075 gnu_actual_obj_type,
4077 }
4078 else
4086 {
4089 tree gnu_byte_offset
4096 }
4101 gnat_node);
4102 }
4109 {
4112 }
4115 gnu_result
4118 /* If the type is VOID, this is a statement, so we need to
4119 generate the code for the call. Handle a Condition, if there
4120 is one. */
4122 {
4129 }
4130 else
4135 /* If the result is a pointer type, see if we are either converting
4136 from a non-pointer or from a pointer to a type with a different
4137 alias set and warn if so. If the result defined in the same unit as
4138 this unchecked conversion, we can allow this because we can know to
4139 make that type have alias set 0. */
4140 {
4151 {
4152 post_error_ne
4155 post_error
4157 gnat_node);
4158 post_error_ne
4161 }
4163 /* The No_Strict_Aliasing flag is not propagated to the back-end for
4164 fat pointers so unconditionally warn in problematic cases. */
4166 {
4167 tree array_type
4174 {
4175 post_error_ne
4178 post_error
4180 gnat_node);
4181 }
4182 }
4183 }
4196 }
4198 /* If we pushed our level as part of processing the elaboration routine,
4199 pop it back now. */
4201 {
4206 }
4208 /* Set the location information into the result. Note that we may have
4209 no result if we tried to build a CALL_EXPR node to a procedure with
4210 no side-effects and optimization is enabled. */
4214 /* If we're supposed to return something of void_type, it means we have
4215 something we're elaborating for effect, so just return. */
4219 /* If the result is a constant that overflows, raise constraint error. */
4222 {
4225 gnu_result
4228 }
4230 /* If our result has side-effects and is of an unconstrained type,
4231 make a SAVE_EXPR so that we can be sure it will only be referenced
4232 once. Note we must do this before any conversions. */
4238 /* Now convert the result to the proper type. If the type is void or if
4239 we have no result, return error_mark_node to show we have no result.
4240 If the type of the result is correct or if we have a label (which doesn't
4241 have any well-defined type), return our result. Also don't do the
4242 conversion if the "desired" type involves a PLACEHOLDER_EXPR in its size
4243 since those are the cases where the front end may have the type wrong due
4244 to "instantiating" the unconstrained record with discriminant values
4245 or if this is a FIELD_DECL. If this is the Name of an assignment
4246 statement or a parameter of a procedure call, return what we have since
4247 the RHS has to be converted to our type there in that case, unless
4248 GNU_RESULT_TYPE has a simpler size. Similarly, if the two types are
4249 record types with the same name, the expression type has integral mode,
4250 and GNU_RESULT_TYPE BLKmode, don't convert. This will be the case when
4251 we are converting from a packable type to its actual type and we need
4252 those conversions to be NOPs in order for assignments into these types to
4253 work properly if the inner object is a bitfield and hence can't have
4254 its address taken. Finally, don't convert integral types that are the
4255 operand of an unchecked conversion since we need to ignore those
4256 conversions (for 'Valid). Otherwise, convert the result to the proper
4257 type. */
4277 && (CONTAINS_PLACEHOLDER_P
4281 {
4282 /* In this case remove padding only if the inner object is of
4283 self-referential size: in that case it must be an object of
4284 unconstrained type with a default discriminant. In other cases,
4285 we want to avoid copying too much data. */
4292 gnu_result);
4293 }
4309 {
4310 /* Remove any padding record, but do nothing more in this case. */
4314 gnu_result);
4315 }
4323 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RESULT. */
4330 }
4331 \f
4332 /* Record the current code position in GNAT_NODE. */
4334 static void
4336 {
4341 }
4343 /* Insert the code for GNAT_NODE at the position saved for that node. */
4345 static void
4347 {
4350 }
4351 \f
4352 /* Start a new statement group chained to the previous group. */
4354 static void
4356 {
4359 /* First see if we can get one from the free list. */
4362 else
4368 }
4370 /* Add GNU_STMT to the current statement group. */
4372 void
4374 {
4377 /* If we're at top level, show everything in here is in use in case
4378 any of it is shared by a subprogram. */
4382 }
4384 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE. */
4386 void
4388 {
4392 }
4394 /* Add a declaration statement for GNU_DECL to the current statement group.
4395 Get SLOC from Entity_Id. */
4397 void
4399 {
4400 tree gnu_stmt;
4402 /* If this is a variable that Gigi is to ignore, we may have been given
4403 an ERROR_MARK. So test for it. We also might have been given a
4404 reference for a renaming. So only do something for a decl. Also
4405 ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */
4411 /* If we are global, we don't want to actually output the DECL_EXPR for
4412 this decl since we already have evaluated the expressions in the
4413 sizes and positions as globals and doing it again would be wrong.
4414 But we do have to mark everything as used. */
4418 else
4419 {
4423 {
4427 }
4428 }
4430 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set,
4431 there are two cases we need to handle here. */
4433 {
4437 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set
4438 and decl has a padded type, convert it to the unpadded type so the
4439 assignment is done properly. */
4442 gnu_lhs
4445 /* Otherwise, if this is going into memory and the initializer isn't
4446 valid for the assembler and loader. Gimplification could do this,
4447 but would be run too late if -fno-unit-at-a-time. */
4454 {
4455 tree gnu_assign_stmt
4464 }
4465 }
4466 }
4468 /* Utility function to mark nodes with TREE_VISITED and types as having their
4469 sized gimplified. Called from walk_tree. We use this to indicate all
4470 variable sizes and positions in global types may not be shared by any
4471 subprogram. */
4473 static tree
4475 {
4479 /* Don't mark a dummy type as visited because we want to mark its sizes
4480 and fields once it's filled in. */
4488 }
4490 /* Likewise, but to mark as unvisited. */
4492 static tree
4495 {
4499 }
4501 /* Add GNU_CLEANUP, a cleanup action, to the current code group. */
4503 static void
4505 {
4507 }
4509 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */
4511 void
4513 {
4516 }
4518 /* Return code corresponding to the current code group. It is normally
4519 a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
4520 BLOCK or cleanups were set. */
4522 static tree
4524 {
4528 /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there
4529 are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK,
4530 make a BIND_EXPR. Note that we nest in that because the cleanup may
4531 reference variables in the block. */
4543 /* Remove this group from the stack and add it to the free list. */
4549 }
4551 /* Add a list of statements from GNAT_LIST, a possibly-empty list of
4552 statements.*/
4554 static void
4556 {
4557 Node_Id gnat_node;
4563 }
4565 /* Build a tree from GNAT_LIST, a possibly-empty list of statements.
4566 If BINDING_P is true, push and pop a binding level around the list. */
4568 static tree
4570 {
4580 }
4581 \f
4582 /* Push and pop routines for stacks. We keep a free list around so we
4583 don't waste tree nodes. */
4585 static void
4587 {
4591 {
4596 }
4597 else
4601 }
4603 static void
4605 {
4611 }
4612 \f
4613 /* GNU_STMT is a statement. We generate code for that statement. */
4615 void
4617 {
4618 #if 0
4620 #endif
4623 {
4624 #if 0
4626 /* First write a volatile ASM_INPUT to prevent anything from being
4627 moved. */
4633 modifier);
4636 #endif
4640 }
4641 }
4642 \f
4643 /* Generate GIMPLE in place for the expression at *EXPR_P. */
4645 int
4647 {
4649 tree op;
4655 {
4657 /* If this is for a scalar, just make a VAR_DECL for it. If for
4658 an aggregate, get a null pointer of the appropriate type and
4659 dereference it. */
4663 integer_zero_node));
4664 else
4665 {
4668 }
4674 /* We should only do this if we are just elaborating for side-effects,
4675 but we can't know that yet. */
4682 /* If we're taking the address of a constant CONSTRUCTOR, force it to
4683 be put into static memory. We know it's going to be readonly given
4684 the semantics we have and it's required to be static memory in
4685 the case when the reference is in an elaboration procedure. */
4687 {
4698 }
4700 /* Otherwise, if we are taking the address of something that is neither
4701 reference, declaration, or constant, make a variable for the operand
4702 here and then take its address. If we don't do it this way, we may
4703 confuse the gimplifier because it needs to know the variable is
4704 addressable at this point. This duplicates code in
4705 internal_get_tmp_var, which is unfortunate. */
4709 {
4722 }
4727 /* We have a kludge here. If the FIELD_DECL is from a fat pointer and is
4728 from an early dummy type, replace it with the proper FIELD_DECL. */
4731 {
4735 }
4737 /* ... fall through ... */
4741 }
4742 }
4744 /* Generate GIMPLE in place for the statement at *STMT_P. */
4746 static enum gimplify_status
4748 {
4752 {
4762 {
4766 /* Set to emit the statements of the loop. */
4769 /* We first emit the start label and then a conditional jump to
4770 the end label if there's a top condition, then the body of the
4771 loop, then a conditional branch to the end label, then the update,
4772 if any, and finally a jump to the start label and the definition
4773 of the end label. */
4775 gnu_start_label),
4776 stmt_p);
4783 void_type_node,
4784 gnu_end_label)),
4785 stmt_p);
4794 void_type_node,
4795 gnu_end_label)),
4796 stmt_p);
4802 gnu_start_label),
4803 stmt_p);
4805 gnu_end_label),
4806 stmt_p);
4808 }
4811 /* Build a statement to jump to the corresponding end label, then
4812 see if it needs to be conditional. */
4821 }
4822 }
4823 \f
4824 /* Force references to each of the entities in packages GNAT_NODE with's
4825 so that the debugging information for all of them are identical
4826 in all clients. Operate recursively on anything it with's, but check
4827 that we aren't elaborating something more than once. */
4829 /* The reason for this routine's existence is two-fold.
4830 First, with some debugging formats, notably MDEBUG on SGI
4831 IRIX, the linker will remove duplicate debugging information if two
4832 clients have identical debugguing information. With the normal scheme
4833 of elaboration, this does not usually occur, since entities in with'ed
4834 packages are elaborated on demand, and if clients have different usage
4835 patterns, the normal case, then the order and selection of entities
4836 will differ. In most cases however, it seems that linkers do not know
4837 how to eliminate duplicate debugging information, even if it is
4838 identical, so the use of this routine would increase the total amount
4839 of debugging information in the final executable.
4841 Second, this routine is called in type_annotate mode, to compute DDA
4842 information for types in withed units, for ASIS use */
4844 static void
4846 {
4849 /* Process each unit only once. As we trace the context of all relevant
4850 units transitively, including generic bodies, we may encounter the
4851 same generic unit repeatedly */
4856 /* Save entities in all context units. A body may have an implicit_with
4857 on its own spec, if the context includes a child unit, so don't save
4858 the spec twice. */
4866 {
4870 {
4887 }
4889 {
4890 Node_Id gnat_body
4893 /* Retrieve compilation unit node of generic body. */
4898 /* If body is available, elaborate its context. */
4901 }
4902 }
4906 }
4907 \f
4908 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
4910 static void
4912 {
4914 tree gnu_old;
4915 tree gnu_new;
4916 tree gnu_init
4921 /* If this is a package, need to generate code for the package. */
4923 {
4924 insert_code_for
4928 }
4930 /* Check for old definition after the above call. This Freeze_Node
4931 might be for one its Itypes. */
4932 gnu_old
4935 /* If this entity has an Address representation clause, GNU_OLD is the
4936 address, so discard it here. */
4940 /* Don't do anything for class-wide types they are always
4941 transformed into their root type. */
4947 /* Don't do anything for subprograms that may have been elaborated before
4948 their freeze nodes. This can happen, for example because of an inner call
4949 in an instance body, or a previous compilation of a spec for inlining
4950 purposes. */
4955 || (gnu_old
4960 /* If we have a non-dummy type old tree, we have nothing to do. Unless
4961 this is the public view of a private type whose full view was not
4962 delayed, this node was never delayed as it should have been.
4963 Also allow this to happen for concurrent types since we may have
4964 frozen both the Corresponding_Record_Type and this type. */
4968 {
4974 }
4976 /* Reset the saved tree, if any, and elaborate the object or type for real.
4977 If there is a full declaration, elaborate it and copy the type to
4978 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
4979 a class wide type or subtype. */
4981 {
4990 }
4994 {
4997 /* Propagate back-annotations from full view to partial view. */
5007 /* The above call may have defined this entity (the simplest example
5008 of this is when we have a private enumeral type since the bounds
5009 will have the public view. */
5015 }
5016 else
5019 /* If we've made any pointers to the old version of this type, we
5020 have to update them. */
5024 }
5025 \f
5026 /* Process the list of inlined subprograms of GNAT_NODE, which is an
5027 N_Compilation_Unit. */
5029 static void
5031 {
5032 Entity_Id gnat_entity;
5033 Node_Id gnat_body;
5035 /* If we can inline, generate RTL for all the inlined subprograms.
5036 Define the entity first so we set DECL_EXTERNAL. */
5041 {
5045 {
5046 /* ??? This really should always be Present. */
5050 gnat_body
5052 }
5055 {
5058 }
5059 }
5060 }
5061 \f
5062 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
5063 We make two passes, one to elaborate anything other than bodies (but
5064 we declare a function if there was no spec). The second pass
5065 elaborates the bodies.
5067 GNAT_END_LIST gives the element in the list past the end. Normally,
5068 this is Empty, but can be First_Real_Statement for a
5069 Handled_Sequence_Of_Statements.
5071 We make a complete pass through both lists if PASS1P is true, then make
5072 the second pass over both lists if PASS2P is true. The lists usually
5073 correspond to the public and private parts of a package. */
5075 static void
5078 {
5080 Node_Id gnat_decl;
5090 {
5091 /* For package specs, we recurse inside the declarations,
5092 thus taking the two pass approach inside the boundary. */
5100 /* Similarly for any declarations in the actions of a
5101 freeze node. */
5103 {
5106 }
5108 /* Package bodies with freeze nodes get their elaboration deferred
5109 until the freeze node, but the code must be placed in the right
5110 place, so record the code position now. */
5118 (Corresponding_Spec
5121 record_code_position
5124 /* We defer most subprogram bodies to the second pass. */
5126 {
5128 {
5134 }
5135 }
5136 /* For bodies and stubs that act as their own specs, the entity
5137 itself must be elaborated in the first pass, because it may
5138 be used in other declarations. */
5140 {
5141 Node_Id gnat_subprog_id =
5148 }
5150 /* Concurrent stubs stand for the corresponding subprogram bodies,
5151 which are deferred like other bodies. */
5154 ;
5155 else
5157 }
5159 /* Here we elaborate everything we deferred above except for package bodies,
5160 which are elaborated at their freeze nodes. Note that we must also
5161 go inside things (package specs and freeze nodes) the first pass did. */
5167 {
5183 }
5184 }
5185 \f
5186 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
5187 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
5188 which we have to check. */
5190 static tree
5192 {
5198 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
5199 we can't do anything since we might be truncating the bounds. No
5200 check is needed in this case. */
5206 /* Checked expressions must be evaluated only once. */
5209 /* There's no good type to use here, so we might as well use
5210 integer_type_node. Note that the form of the check is
5211 (not (expr >= lo)) or (not (expr >= hi))
5212 the reason for this slightly convoluted form is that NaN's
5213 are not considered to be in range in the float case. */
5214 return emit_check
5216 invert_truthvalue
5220 invert_truthvalue
5224 gnu_high)))),
5226 }
5227 \f
5228 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
5229 which we are about to index, GNU_EXPR is the index expression to be
5230 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
5231 against which GNU_EXPR has to be checked. Note that for index
5232 checking we cannot use the emit_range_check function (although very
5233 similar code needs to be generated in both cases) since for index
5234 checking the array type against which we are checking the indeces
5235 may be unconstrained and consequently we need to retrieve the
5236 actual index bounds from the array object itself
5237 (GNU_ARRAY_OBJECT). The place where we need to do that is in
5238 subprograms having unconstrained array formal parameters */
5240 static tree
5242 tree gnu_expr,
5243 tree gnu_low,
5244 tree gnu_high)
5245 {
5246 tree gnu_expr_check;
5248 /* Checked expressions must be evaluated only once. */
5251 /* Must do this computation in the base type in case the expression's
5252 type is an unsigned subtypes. */
5255 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
5256 the object we are handling. */
5260 /* There's no good type to use here, so we might as well use
5261 integer_type_node. */
5262 return emit_check
5265 gnu_expr_check,
5267 gnu_low)),
5269 gnu_expr_check,
5271 gnu_high))),
5273 }
5274 \f
5275 /* GNU_COND contains the condition corresponding to an access, discriminant or
5276 range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if
5277 GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true.
5278 REASON is the code that says why the exception was raised. */
5280 static tree
5282 {
5283 tree gnu_call;
5284 tree gnu_result;
5288 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
5289 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
5290 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
5291 out. */
5295 gnu_expr));
5297 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
5298 protect it. Otherwise, show GNU_RESULT has no side effects: we
5299 don't need to evaluate it just for the check. */
5301 gnu_result
5303 else
5306 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
5307 we will repeatedly do the test. It would be nice if GCC was able
5308 to optimize this and only do it once. */
5310 }
5311 \f
5312 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
5313 overflow checks if OVERFLOW_P is nonzero and range checks if
5314 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
5315 If TRUNCATE_P is nonzero, do a float to integer conversion with
5316 truncation; otherwise round. */
5318 static tree
5321 {
5328 /* If we are not doing any checks, the output is an integral type, and
5329 the input is not a floating type, just do the conversion. This
5330 shortcut is required to avoid problems with packed array types
5331 and simplifies code in all cases anyway. */
5336 /* First convert the expression to its base type. This
5337 will never generate code, but makes the tests below much simpler.
5338 But don't do this if converting from an integer type to an unconstrained
5339 array type since then we need to get the bounds from the original
5340 (unpacked) type. */
5344 /* If overflow checks are requested, we need to be sure the result will
5345 fit in the output base type. But don't do this if the input
5346 is integer and the output floating-point. */
5349 {
5350 /* Ensure GNU_EXPR only gets evaluated once. */
5358 /* Convert the lower bounds to signed types, so we're sure we're
5359 comparing them properly. Likewise, convert the upper bounds
5360 to unsigned types. */
5374 /* Check each bound separately and only if the result bound
5375 is tighter than the bound on the input type. Note that all the
5376 types are base types, so the bounds must be constant. Also,
5377 the comparison is done in the base type of the input, which
5378 always has the proper signedness. First check for input
5379 integer (which means output integer), output float (which means
5380 both float), or mixed, in which case we always compare.
5381 Note that we have to do the comparison which would *fail* in the
5382 case of an error since if it's an FP comparison and one of the
5383 values is a NaN or Inf, the comparison will fail. */
5390 gnu_cond
5391 = invert_truthvalue
5394 gnu_out_lb)));
5402 gnu_cond
5404 invert_truthvalue
5406 gnu_input,
5408 gnu_out_ub))));
5412 CE_Overflow_Check_Failed);
5413 }
5415 /* Now convert to the result base type. If this is a non-truncating
5416 float-to-integer conversion, round. */
5419 {
5425 /* The following calculations depend on proper rounding to even
5426 of each arithmetic operation. In order to prevent excess
5427 precision from spoiling this property, use the widest hardware
5428 floating-point type.
5430 FIXME: For maximum efficiency, this should only be done for machines
5431 and types where intermediates may have extra precision. */
5434 /* FIXME: Should not have padding in the first place */
5439 /* Compute the exact value calc_type'Pred (0.5) at compile time. */
5443 half_minus_pred_half);
5446 /* If the input is strictly negative, subtract this value
5447 and otherwise add it from the input. For 0.5, the result
5448 is exactly between 1.0 and the machine number preceding 1.0
5449 (for calc_type). Since the last bit of 1.0 is even, this 0.5
5450 will round to 1.0, while all other number with an absolute
5451 value less than 0.5 round to 0.0. For larger numbers exactly
5452 halfway between integers, rounding will always be correct as
5453 the true mathematical result will be closer to the higher
5454 integer compared to the lower one. So, this constant works
5455 for all floating-point numbers.
5457 The reason to use the same constant with subtract/add instead
5458 of a positive and negative constant is to allow the comparison
5459 to be scheduled in parallel with retrieval of the constant and
5460 conversion of the input to the calc_type (if necessary).
5461 */
5468 gnu_add_pred_half
5470 gnu_subtract_pred_half
5474 }
5480 else
5483 /* Finally, do the range check if requested. Note that if the
5484 result type is a modular type, the range check is actually
5485 an overflow check. */
5493 }
5494 \f
5495 /* Return 1 if GNU_EXPR can be directly addressed. This is the case unless
5496 it is an expression involving computation or if it involves a reference
5497 to a bitfield or to a field not sufficiently aligned for its type. */
5499 static bool
5501 {
5503 {
5508 /* All DECLs are addressable: if they are in a register, we can force
5509 them to memory. */
5521 && (!STRICT_ALIGNMENT
5522 /* If the field was marked as "semantically" addressable
5523 in create_field_decl, we are guaranteed that it can
5524 be directly addressed. */
5526 /* Otherwise it can nevertheless be directly addressed
5527 if it has been sufficiently aligned in the record. */
5542 {
5543 /* This is addressable if we can avoid a copy. */
5557 }
5561 }
5562 }
5563 \f
5564 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
5565 a separate Freeze node exists, delay the bulk of the processing. Otherwise
5566 make a GCC type for GNAT_ENTITY and set up the correspondence. */
5568 void
5570 {
5571 tree gnu_old
5573 tree gnu_new;
5575 /* If we are to delay elaboration of this type, just do any
5576 elaborations needed for expressions within the declaration and
5577 make a dummy type entry for this node and its Full_View (if
5578 any) in case something points to it. Don't do this if it
5579 has already been done (the only way that can happen is if
5580 the private completion is also delayed). */
5586 {
5590 {
5599 }
5602 }
5604 /* If we saved away a dummy type for this node it means that this
5605 made the type that corresponds to the full type of an incomplete
5606 type. Clear that type for now and then update the type in the
5607 pointers. */
5609 {
5612 {
5613 /* If this was a withed access type, this is not an error
5614 and merely indicates we've already elaborated the type
5615 already. */
5618 }
5621 }
5623 /* Now fully elaborate the type. */
5627 /* If we have an old type and we've made pointers to this type,
5628 update those pointers. */
5633 /* If this is a record type corresponding to a task or protected type
5634 that is a completion of an incomplete type, perform a similar update
5635 on the type. */
5636 /* ??? Including protected types here is a guess. */
5641 {
5642 tree gnu_task_old
5652 }
5653 }
5654 \f
5655 /* GNAT_ENTITY is the type of the resulting constructors,
5656 GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate,
5657 and GNU_TYPE is the GCC type of the corresponding record.
5659 Return a CONSTRUCTOR to build the record. */
5661 static tree
5663 {
5666 /* We test for GNU_FIELD being empty in the case where a variant
5667 was the last thing since we don't take things off GNAT_ASSOC in
5668 that case. We check GNAT_ASSOC in case we have a variant, but it
5669 has no fields. */
5673 {
5678 /* The expander is supposed to put a single component selector name
5679 in every record component association */
5682 /* Ignore fields that have Corresponding_Discriminants since we'll
5683 be setting that field in the parent. */
5688 /* Also ignore discriminants of Unchecked_Unions. */
5693 /* Before assigning a value in an aggregate make sure range checks
5694 are done if required. Then convert to the type of the field. */
5700 /* Add the field and expression to the list. */
5702 }
5706 #ifdef ENABLE_CHECKING
5707 {
5708 tree gnu_field;
5710 /* Verify every enty in GNU_LIST was used. */
5713 }
5714 #endif
5717 }
5719 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
5720 is the first element of an array aggregate. It may itself be an
5721 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
5722 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
5723 of the array component. It is needed for range checking. */
5725 static tree
5727 Entity_Id gnat_component_type)
5728 {
5731 tree gnu_expr;
5734 {
5735 /* If the expression is itself an array aggregate then first build the
5736 innermost constructor if it is part of our array (multi-dimensional
5737 case). */
5744 gnat_component_type);
5745 else
5746 {
5749 /* before assigning the element to the array make sure it is
5750 in range */
5753 }
5755 gnu_expr_list
5757 gnu_expr_list);
5760 }
5763 }
5764 \f
5765 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
5766 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
5767 of the associations that are from RECORD_TYPE. If we see an internal
5768 record, make a recursive call to fill it in as well. */
5770 static tree
5772 {
5777 {
5780 /* _Parent is an internal field, but may have values in the aggregate,
5781 so check for values first. */
5783 {
5786 }
5789 {
5794 }
5795 else
5796 /* If we have a record subtype, the names will match, but not the
5797 actual FIELD_DECLs. */
5800 {
5803 }
5809 }
5812 }
5813 \f
5814 /* EXP is to be treated as an array or record. Handle the cases when it is
5815 an access object and perform the required dereferences. */
5817 static tree
5819 {
5820 /* If the type is a pointer, dereference it. */
5825 /* If we got a padded type, remove it too. */
5831 }
5832 \f
5833 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
5835 tree
5837 {
5840 /* If this has no side effects, we don't need to do anything. */
5844 /* If it is a conversion, protect what's inside the conversion.
5845 Similarly, if we're indirectly referencing something, we only
5846 actually need to protect the address since the data itself can't
5847 change in these situations. */
5856 /* If EXP is a fat pointer or something that can be placed into a register,
5857 just make a SAVE_EXPR. */
5861 /* Otherwise, dereference, protect the address, and re-reference. */
5862 else
5863 return
5867 exp)));
5868 }
5869 \f
5870 /* This is equivalent to stabilize_reference in GCC's tree.c, but we know how
5871 to handle our new nodes and we take extra arguments:
5873 FORCE says whether to force evaluation of everything,
5875 SUCCESS we set to true unless we walk through something we don't know how
5876 to stabilize, or through something which is not an lvalue and LVALUES_ONLY
5877 is true, in which cases we set to false. */
5879 tree
5882 {
5885 tree result;
5887 /* Assume we'll success unless proven otherwise. */
5891 {
5895 /* No action is needed in this case. */
5899 /* A standalone ADDR_EXPR is never an lvalue, and this one can't
5900 be nested inside an outer INDIRECT_REF, since INDIREC_REF goes
5901 straight to stabilize_1. */
5905 /* ... Fallthru ... */
5915 result
5925 force));
5940 force),
5942 force));
5951 force),
5958 force),
5966 /* ... Fallthru to failure ... */
5968 /* If arg isn't a kind of lvalue we recognize, make no change.
5969 Caller should recognize the error for an invalid lvalue. */
5971 failure:
5974 }
5978 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS attached to the initial
5979 expression may not be sustained across some paths, such as the way via
5980 build1 for INDIRECT_REF. We re-populate those flags here for the general
5981 case, which is consistent with the GCC version of this routine.
5983 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
5984 paths introduce side effects where there was none initially (e.g. calls
5985 to save_expr), and we also want to keep track of that. */
5991 }
5993 /* Wrapper around maybe_stabilize_reference, for common uses without
5994 lvalue restrictions and without need to examine the success
5995 indication. */
5997 tree
5999 {
6002 }
6004 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
6005 arg to force a SAVE_EXPR for everything. */
6007 static tree
6009 {
6012 tree result;
6014 /* We cannot ignore const expressions because it might be a reference
6015 to a const array but whose index contains side-effects. But we can
6016 ignore things that are actual constant or that already have been
6017 handled by this function. */
6023 {
6031 /* If this is a COMPONENT_REF of a fat pointer, save the entire
6032 fat pointer. This may be more efficient, but will also allow
6033 us to more easily find the match for the PLACEHOLDER_EXPR. */
6038 force),
6042 else
6047 /* Constants need no processing. In fact, we should never reach
6048 here. */
6052 /* Recursively stabilize each operand. */
6056 force));
6060 /* Recursively stabilize each operand. */
6063 force));
6068 }
6075 }
6077 /* Build a global constructor or destructor function. METHOD_TYPE gives
6078 the type of the function and CDTORS points to the list of constructor
6079 or destructor functions to be invoked. FIXME: Migrate into cgraph. */
6081 static void
6083 {
6087 {
6092 NULL_TREE);
6094 }
6097 }
6098 \f
6101 /* Convert Sloc into *LOCUS (a location_t). Return true if this Sloc
6102 corresponds to a source code location and false if it doesn't. In the
6103 latter case, we don't update *LOCUS. We also set the Gigi global variable
6104 REF_FILENAME to the reference file name as given by sinput (i.e no
6105 directory). */
6107 bool
6109 {
6110 /* If node not from source code, ignore. */
6114 /* Use the identifier table to make a hashed, permanent copy of the filename,
6115 since the name table gets reallocated after Gigi returns but before all
6116 the debugging information is output. The __gnat_to_canonical_file_spec
6117 call translates filenames from pragmas Source_Reference that contain host
6118 style syntax not understood by gdb. */
6119 locus->file
6120 = IDENTIFIER_POINTER
6121 (get_identifier
6122 (__gnat_to_canonical_file_spec
6127 ref_filename
6128 = IDENTIFIER_POINTER
6129 (get_identifier
6133 }
6135 /* Similar to annotate_with_locus, but start with the Sloc of GNAT_NODE and
6136 don't do anything if it doesn't correspond to a source location. */
6138 static void
6140 {
6141 location_t locus;
6147 }
6148 \f
6149 /* Post an error message. MSG is the error message, properly annotated.
6150 NODE is the node at which to post the error and the node to use for the
6151 "&" substitution. */
6153 void
6155 {
6156 String_Template temp;
6157 Fat_Pointer fp;
6163 }
6165 /* Similar, but NODE is the node at which to post the error and ENT
6166 is the node to use for the "&" substitution. */
6168 void
6170 {
6171 String_Template temp;
6172 Fat_Pointer fp;
6178 }
6180 /* Similar, but NODE is the node at which to post the error, ENT is the node
6181 to use for the "&" substitution, and N is the number to use for the ^. */
6183 void
6185 {
6186 String_Template temp;
6187 Fat_Pointer fp;
6195 }
6196 \f
6197 /* Similar to post_error_ne_num, but T is a GCC tree representing the
6198 number to write. If the tree represents a constant that fits within
6199 a host integer, the text inside curly brackets in MSG will be output
6200 (presumably including a '^'). Otherwise that text will not be output
6201 and the text inside square brackets will be output instead. */
6203 void
6205 {
6208 Fat_Pointer fp;
6216 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
6217 &&
6218 compare_tree_int
6220 #endif
6221 )
6222 {
6225 }
6226 else
6230 {
6236 ;
6237 else
6239 }
6246 }
6248 /* Similar to post_error_ne_tree, except that NUM is a second
6249 integer to write in the message. */
6251 void
6253 Node_Id node,
6254 Entity_Id ent,
6255 tree t,
6257 {
6260 }
6261 \f
6262 /* Initialize the table that maps GNAT codes to GCC codes for simple
6263 binary and unary operations. */
6265 void
6267 {
6293 }