| blob | f8698c5a77adb218c212bb3678cf9ff82b327c83 |
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 */
288 }
289 \f
290 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Identifier,
291 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
292 where we should place the result type. */
294 static tree
296 {
297 tree gnu_result_type;
298 tree gnu_result;
301 /* If the Etype of this node does not equal the Etype of the Entity,
302 something is wrong with the entity map, probably in generic
303 instantiation. However, this does not apply to types. Since we sometime
304 have strange Ekind's, just do this test for objects. Also, if the Etype of
305 the Entity is private, the Etype of the N_Identifier is allowed to be the
306 full type and also we consider a packed array type to be the same as the
307 original type. Similarly, a class-wide type is equivalent to a subtype of
308 itself. Finally, if the types are Itypes, one may be a copy of the other,
309 which is also legal. */
332 /* If this is a reference to a deferred constant whose partial view is an
333 unconstrained private type, the proper type is on the full view of the
334 constant, not on the full view of the type, which may be unconstrained.
336 This may be a reference to a type, for example in the prefix of the
337 attribute Position, generated for dispatching code (see Make_DT in
338 exp_disp,adb). In that case we need the type itself, not is parent,
339 in particular if it is a derived type */
344 {
348 }
349 else
350 {
351 /* Expand the type of this identifier first, in case it is an enumeral
352 literal, which only get made when the type is expanded. There is no
353 order-of-elaboration issue here. We want to use the Actual_Subtype if
354 it has already been elaborated, otherwise the Etype. Avoid using
355 Actual_Subtype for packed arrays to simplify things. */
363 else
367 }
371 /* If we are in an exception handler, force this variable into memory to
372 ensure optimization does not remove stores that appear redundant but are
373 actually needed in case an exception occurs.
375 ??? Note that we need not do this if the variable is declared within the
376 handler, only if it is referenced in the handler and declared in an
377 enclosing block, but we have no way of testing that right now.
379 ??? Also, for now all we can do is make it volatile. But we only
380 do this for SJLJ. */
385 /* Some objects (such as parameters passed by reference, globals of
386 variable size, and renamed objects) actually represent the address
387 of the object. In that case, we must do the dereference. Likewise,
388 deal with parameters to foreign convention subprograms. Call fold
389 here since GNU_RESULT may be a CONST_DECL. */
394 {
396 tree renamed_obj;
400 gnu_result
403 gnu_result));
405 /* If it's a renaming pointer and we are at the right binding level,
406 we can reference the renamed object directly, since the renamed
407 expression has been protected against multiple evaluations. */
413 else
418 }
420 /* The GNAT tree has the type of a function as the type of its result. Also
421 use the type of the result if the Etype is a subtype which is nominally
422 unconstrained. But remove any padding from the resulting type. */
425 {
430 }
432 /* We always want to return the underlying INTEGER_CST for an enumeration
433 literal to avoid the need to call fold in lots of places. But don't do
434 this is the parent will be taking the address of this object. */
436 {
450 }
454 }
455 \f
456 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Pragma. Return
457 any statements we generate. */
459 static tree
461 {
462 Node_Id gnat_temp;
465 /* Check for (and ignore) unrecognized pragma and do nothing if we are just
466 annotating types. */
471 {
473 /* Do nothing at top level: all such variables are already viewable. */
480 {
489 }
495 {
508 }
515 }
518 }
519 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Attribute,
520 to a GCC tree, which is returned. GNU_RESULT_TYPE_P is a pointer to
521 where we should place the result type. ATTRIBUTE is the attribute ID. */
523 static tree
525 {
527 tree gnu_result_type;
528 tree gnu_expr;
533 /* If the input is a NULL_EXPR, make a new one. */
535 {
539 }
542 {
545 /* These are just conversions until since representation clauses for
546 enumerations are handled in the front end. */
547 {
554 }
559 /* These just add or subject the constant 1. Representation clauses for
560 enumerations are handled in the front-end. */
565 {
567 gnu_expr
568 = emit_check
570 gnu_expr,
571 attribute == Attr_Pred
575 }
577 gnu_result
586 /* Conversions don't change something's address but can cause us to miss
587 the COMPONENT_REF case below, so strip them off. */
591 /* If we are taking 'Address of an unconstrained object, this is the
592 pointer to the underlying array. */
596 /* ... fall through ... */
602 gnu_result
609 /* For 'Code_Address, find an inner ADDR_EXPR and mark it so that we
610 don't try to build a trampoline. */
612 {
621 }
625 {
626 tree gnu_obj_type;
631 /* If this is an unconstrained array, we know the object must have been
632 allocated with the template in front of the object. So compute the
633 template address.*/
635 gnu_ptr
637 (TYPE_OBJECT_RECORD_TYPE
639 gnu_ptr);
644 {
647 tree gnu_byte_offset
654 }
657 }
666 /* Remove NOPS from gnu_expr and conversions from gnu_prefix.
667 We only use GNU_EXPR to see if a COMPONENT_REF was involved. */
670 ;
676 /* Replace an unconstrained array type with the type of the underlying
677 array. We can't do this with a call to maybe_unconstrained_array
678 since we may have a TYPE_DECL. For 'Max_Size_In_Storage_Elements,
679 use the record type that will be used to allocate the object and its
680 template. */
682 {
686 }
688 /* If we're looking for the size of a field, return the field size.
689 Otherwise, if the prefix is an object, or if 'Object_Size or
690 'Max_Size_In_Storage_Elements has been specified, the result is the
691 GCC size of the type. Otherwise, the result is the RM_Size of the
692 type. */
698 {
699 /* If this is a padded type, the GCC size isn't relevant to the
700 programmer. Normally, what we want is the RM_Size, which was set
701 from the specified size, but if it was not set, we want the size
702 of the relevant field. Using the MAX of those two produces the
703 right result in all case. Don't use the size of the field if it's
704 a self-referential type, since that's never what's wanted. */
708 {
712 gnu_result
715 }
717 {
723 {
727 }
730 }
731 else
733 }
734 else
739 /* Deal with a self-referential size by returning the maximum size for a
740 type and by qualifying the size with the object for 'Size of an
741 object. */
743 {
746 else
748 }
750 /* If the type contains a template, subtract its size. */
758 /* Always perform division using unsigned arithmetic as the size cannot
759 be negative, but may be an overflowed positive value. This provides
760 correct results for sizes up to 512 MB.
762 ??? Size should be calculated in storage elements directly. */
783 else
793 {
800 else
801 gnu_result
802 = build_binary_op
804 build_binary_op
816 }
818 /* ... fall through ... */
821 {
826 /* Make sure any implicit dereference gets done. */
834 {
836 tree gnu_type_temp;
842 ;
845 }
852 gnu_result
855 gnu_result
857 else
858 /* 'Length or 'Range_Length. */
859 {
860 tree gnu_compute_type
864 gnu_result
865 = build_binary_op
867 build_binary_op
869 build_binary_op
872 TYPE_MAX_VALUE
875 TYPE_MIN_VALUE
879 }
881 /* If this has a PLACEHOLDER_EXPR, qualify it by the object we are
882 handling. Note that these attributes could not have been used on
883 an unconstrained array type. */
885 gnu_prefix);
887 }
894 {
895 HOST_WIDE_INT bitsize;
896 HOST_WIDE_INT bitpos;
897 tree gnu_offset;
898 tree gnu_field_bitpos;
899 tree gnu_field_offset;
900 tree gnu_inner;
908 /* We can have 'Bit on any object, but if it isn't a COMPONENT_REF,
909 the result is 0. Don't allow 'Bit on a bare component, though. */
913 {
916 }
918 else
927 {
935 {
936 gnu_field_bitpos
939 gnu_field_offset
942 }
943 }
945 {
948 }
949 else
950 {
953 }
956 {
971 bitsize_one_node);
977 }
979 /* If this has a PLACEHOLDER_EXPR, qualify it by the object
980 we are handling. */
983 }
987 {
995 }
1023 /* Note this size cannot be self-referential. */
1030 /* This is just a zero cast to the pointer type for
1031 our prefix and dereferenced. */
1033 gnu_result
1036 integer_zero_node));
1041 {
1048 {
1053 ;
1054 }
1062 && (DECL_BY_COMPONENT_PTR_P
1066 }
1070 /* Say we have an unimplemented attribute. Then set the value to be
1071 returned to be a zero and hope that's something we can convert to the
1072 type of this attribute. */
1077 }
1079 /* If this is an attribute where the prefix was unused, force a use of it if
1080 it has a side-effect. But don't do it if the prefix is just an entity
1081 name. However, if an access check is needed, we must do it. See second
1082 example in AARM 11.6(5.e). */
1090 }
1091 \f
1092 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Case_Statement,
1093 to a GCC tree, which is returned. */
1095 static tree
1097 {
1098 tree gnu_result;
1099 tree gnu_expr;
1100 Node_Id gnat_when;
1105 /* The range of values in a case statement is determined by the rules in
1106 RM 5.4(7-9). In almost all cases, this range is represented by the Etype
1107 of the expression. One exception arises in the case of a simple name that
1108 is parenthesized. This still has the Etype of the name, but since it is
1109 not a name, para 7 does not apply, and we need to go to the base type.
1110 This is the only case where parenthesization affects the dynamic
1111 semantics (i.e. the range of possible values at runtime that is covered
1112 by the others alternative.
1114 Another exception is if the subtype of the expression is non-static. In
1115 that case, we also have to use the base type. */
1121 /* We build a SWITCH_EXPR that contains the code with interspersed
1122 CASE_LABEL_EXPRs for each label. */
1129 {
1130 Node_Id gnat_choice;
1132 /* First compile all the different case choices for the current WHEN
1133 alternative. */
1136 {
1140 {
1155 /* This represents either a subtype range or a static value of
1156 some kind; Ekind says which. If a static value, fall through
1157 to the next case. */
1159 {
1165 }
1167 /* ... fall through ... */
1179 }
1184 gnat_choice);
1185 }
1187 /* Push a binding level here in case variables are declared since we want
1188 them to be local to this set of statements instead of the block
1189 containing the Case statement. */
1193 }
1195 /* Now emit a definition of the label all the cases branched to. */
1203 }
1204 \f
1205 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement,
1206 to a GCC tree, which is returned. */
1208 static tree
1210 {
1211 /* ??? It would be nice to use "build" here, but there's no build5. */
1217 tree gnu_result;
1224 /* Save the end label of this LOOP_STMT in a stack so that the corresponding
1225 N_Exit_Statement can find it. */
1229 /* Set the condition that under which the loop should continue.
1230 For "LOOP .... END LOOP;" the condition is always true. */
1232 ;
1233 /* The case "WHILE condition LOOP ..... END LOOP;" */
1237 else
1238 {
1239 /* We have an iteration scheme. */
1254 /* We know the loop variable will not overflow if GNU_LAST is a constant
1255 and is not equal to GNU_LIMIT. If it might overflow, we have to move
1256 the limit test to the end of the loop. In that case, we have to test
1257 for an empty loop outside the loop. */
1261 {
1262 gnu_cond_expr
1268 }
1270 /* Open a new nesting level that will surround the loop to declare the
1271 loop index variable. */
1275 /* Declare the loop index and set it to its initial value. */
1280 /* The loop variable might be a padded type, so use `convert' to get a
1281 reference to the inner variable if so. */
1284 /* Set either the top or bottom exit condition as appropriate depending
1285 on whether or not we know an overflow cannot occur. */
1290 else
1299 gnu_loop_var,
1301 integer_one_node));
1303 gnat_iter_scheme);
1304 }
1306 /* If the loop was named, have the name point to this loop. In this case,
1307 the association is not a ..._DECL node, but the end label from this
1308 LOOP_STMT. */
1313 /* Make the loop body into its own block, so any allocated storage will be
1314 released every iteration. This is needed for stack allocation. */
1318 /* If we declared a variable, then we are in a statement group for that
1319 declaration. Add the LOOP_STMT to it and make that the "loop". */
1321 {
1325 }
1327 /* If we have an outer COND_EXPR, that's our result and this loop is its
1328 "true" statement. Otherwise, the result is the LOOP_STMT. */
1330 {
1334 }
1335 else
1341 }
1342 \f
1343 /* Subroutine of gnat_to_gnu to process gnat_node, an N_Subprogram_Body. We
1344 don't return anything. */
1346 static void
1348 {
1349 /* Save debug output mode in case it is reset. */
1352 /* Defining identifier of a parameter to the subprogram. */
1353 Entity_Id gnat_param;
1354 /* The defining identifier for the subprogram body. Note that if a
1355 specification has appeared before for this body, then the identifier
1356 occurring in that specification will also be a defining identifier and all
1357 the calls to this subprogram will point to that specification. */
1358 Entity_Id gnat_subprog_id
1361 /* The FUNCTION_DECL node corresponding to the subprogram spec. */
1362 tree gnu_subprog_decl;
1363 /* The FUNCTION_TYPE node corresponding to the subprogram spec. */
1364 tree gnu_subprog_type;
1365 tree gnu_cico_list;
1366 tree gnu_result;
1368 /* If this is a generic object or if it has been eliminated,
1369 ignore it. */
1375 /* If debug information is suppressed for the subprogram, turn debug
1376 mode off for the duration of processing. */
1378 {
1381 }
1383 /* If this subprogram acts as its own spec, define it. Otherwise, just get
1384 the already-elaborated tree node. However, if this subprogram had its
1385 elaboration deferred, we will already have made a tree node for it. So
1386 treat it as not being defined in that case. Such a subprogram cannot
1387 have an address clause or a freeze node, so this test is safe, though it
1388 does disable some otherwise-useful error checking. */
1389 gnu_subprog_decl
1396 /* Set the line number in the decl to correspond to that of the body so that
1397 the line number notes are written
1398 correctly. */
1404 /* If there are OUT parameters, we need to ensure that the return statement
1405 properly copies them out. We do this by making a new block and converting
1406 any inner return into a goto to a label at the end of the block. */
1410 /* Get a tree corresponding to the code for the subprogram. */
1414 /* See if there are any parameters for which we don't yet have GCC entities.
1415 These must be for OUT parameters for which we will be making VAR_DECL
1416 nodes here. Fill them in to TYPE_CI_CO_LIST, which must contain the empty
1417 entry as well. We can match up the entries because TYPE_CI_CO_LIST is in
1418 the order of the parameters. */
1423 {
1424 /* Skip any entries that have been already filled in; they must
1425 correspond to IN OUT parameters. */
1428 ;
1430 /* Do any needed references for padded types. */
1434 }
1438 /* Generate the code of the subprogram itself. A return statement will be
1439 present and any OUT parameters will be handled there. */
1444 /* If we made a special return label, we need to make a block that contains
1445 the definition of that label and the copying to the return value. That
1446 block first contains the function, then the label and copy statement. */
1448 {
1449 tree gnu_retval;
1460 else
1462 gnu_cico_list);
1467 add_stmt_with_node
1469 gnat_node);
1472 }
1476 /* Initialize the information node for the function and set the
1477 end location. */
1479 Sloc_to_locus
1487 /* Disconnect the trees for parameters that we made variables for from the
1488 GNAT entities since these are unusable after we end the function. */
1498 }
1499 \f
1500 /* Subroutine of gnat_to_gnu to translate gnat_node, either an N_Function_Call
1501 or an N_Procedure_Call_Statement, to a GCC tree, which is returned.
1502 GNU_RESULT_TYPE_P is a pointer to where we should place the result type.
1503 If GNU_TARGET is non-null, this must be a function call and the result
1504 of the call is to be placed into that object. */
1506 static tree
1508 {
1509 tree gnu_result;
1510 /* The GCC node corresponding to the GNAT subprogram name. This can either
1511 be a FUNCTION_DECL node if we are dealing with a standard subprogram call,
1512 or an indirect reference expression (an INDIRECT_REF node) pointing to a
1513 subprogram. */
1515 /* The FUNCTION_TYPE node giving the GCC type of the subprogram. */
1518 gnu_subprog_node);
1519 Entity_Id gnat_formal;
1520 Node_Id gnat_actual;
1525 tree gnu_subprog_call;
1528 {
1535 }
1539 /* If we are calling a stubbed function, make this into a raise of
1540 Program_Error. Elaborate all our args first. */
1543 {
1549 {
1550 tree call_expr
1554 {
1557 }
1558 else
1560 }
1561 }
1563 /* If we are calling by supplying a pointer to a target, set up that
1564 pointer as the first argument. Use GNU_TARGET if one was passed;
1565 otherwise, make a target by building a variable of the maximum size
1566 of the type. */
1568 {
1569 tree gnu_real_ret_type
1573 {
1574 tree gnu_obj_type
1580 /* ??? We may be about to create a static temporary if we happen to
1581 be at the global binding level. That's a regression from what
1582 the 3.x back-end would generate in the same situation, but we
1583 don't have a mechanism in Gigi for creating automatic variables
1584 in the elaboration routines. */
1585 gnu_target
1588 gnat_node);
1589 }
1591 gnu_actual_list
1595 gnu_target,
1597 NULL_TREE);
1599 }
1601 /* The only way we can be making a call via an access type is if Name is an
1602 explicit dereference. In that case, get the list of formal args from the
1603 type the access type is pointing to. Otherwise, get the formals from
1604 entity being called. */
1608 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
1610 else
1613 /* Create the list of the actual parameters as GCC expects it, namely a chain
1614 of TREE_LIST nodes in which the TREE_VALUE field of each node is a
1615 parameter-expression and the TREE_PURPOSE field is null. Skip OUT
1616 parameters not passed by reference and don't need to be copied in. */
1621 {
1622 tree gnu_formal
1626 /* We treat a conversion between aggregate types as if it is an
1627 unchecked conversion. */
1628 bool unchecked_convert_p
1632 Node_Id gnat_name = (unchecked_convert_p
1636 tree gnu_actual;
1638 /* If it's possible we may need to use this expression twice, make sure
1639 than any side-effects are handled via SAVE_EXPRs. Likewise if we need
1640 to force side-effects before the call.
1642 ??? This is more conservative than we need since we don't need to do
1643 this for pass-by-ref with no conversion. If we are passing a
1644 non-addressable Out or In Out parameter by reference, pass the address
1645 of a copy and set up to copy back out after the call. */
1647 {
1651 && gnu_formal
1656 {
1658 tree gnu_temp;
1660 /* For users of Starlet we issue a warning because the
1661 interface apparently assumes that by-ref parameters
1662 outlive the procedure invocation. The code still
1663 will not work as intended, but we cannot do much
1664 better since other low-level parts of the back-end
1665 would allocate temporaries at will because of the
1666 misalignment if we did not do so here. */
1669 {
1670 post_error
1672 gnat_actual);
1673 post_error_ne
1676 post_error_ne
1679 }
1681 /* Remove any unpadding on the actual and make a copy. But if
1682 the actual is a justified modular type, first convert
1683 to it. */
1687 && (TYPE_IS_PADDING_P
1696 /* Since we're going to take the address of the SAVE_EXPR, we
1697 don't want it to be marked as unchanging. So set
1698 TREE_ADDRESSABLE. */
1701 {
1704 }
1706 /* Set up to move the copy back to the original. */
1712 /* Account for next statement just below. */
1714 }
1715 }
1717 /* If this was a procedure call, we may not have removed any padding.
1718 So do it here for the part we will use as an input, if any. */
1724 gnu_actual);
1726 /* Unless this is an In parameter, we must remove any LJM building
1727 from GNU_NAME. */
1733 gnu_name);
1736 && !unchecked_convert_p
1740 /* Do any needed conversions. We need only check for unchecked
1741 conversion since normal conversions will be handled by just
1742 converting to the formal type. */
1744 {
1745 gnu_actual
1747 gnu_actual,
1752 /* One we've done the unchecked conversion, we still must ensure that
1753 the object is in range of the formal's type. */
1758 }
1760 /* We may have suppressed a conversion to the Etype of the actual since
1761 the parent is a procedure call. So add the conversion here. */
1763 gnu_actual);
1768 /* If we have not saved a GCC object for the formal, it means it is an
1769 OUT parameter not passed by reference and that does not need to be
1770 copied in. Otherwise, look at the PARM_DECL to see if it is passed by
1771 reference. */
1774 {
1776 {
1779 /* If we have a padded type, be sure we've removed padding. */
1784 gnu_actual);
1786 /* If we have the constructed subtype of an aliased object
1787 with an unconstrained nominal subtype, the type of the
1788 actual includes the template, although it is formally
1789 constrained. So we need to convert it back to the real
1790 constructed subtype to retrieve the constrained part
1791 and takes its address. */
1798 gnu_actual);
1799 }
1801 /* Otherwise, if we have a non-addressable COMPONENT_REF of a
1802 variable-size type see if it's doing a unpadding operation. If
1803 so, remove that operation since we have no way of allocating the
1804 required temporary. */
1814 /* The symmetry of the paths to the type of an entity is broken here
1815 since arguments don't know that they will be passed by ref. */
1818 }
1821 {
1828 {
1831 }
1833 /* Take the address of the object and convert to the proper pointer
1834 type. We'd like to actually compute the address of the beginning
1835 of the array using an ADDR_EXPR of an ARRAY_REF, but there's a
1836 possibility that the ARRAY_REF might return a constant and we'd be
1837 getting the wrong address. Neither approach is exactly correct,
1838 but this is the most likely to work in all cases. */
1841 gnu_actual));
1842 }
1845 {
1846 /* If arg is 'Null_Parameter, pass zero descriptor. */
1851 integer_zero_node);
1852 else
1855 gnat_formal));
1856 }
1857 else
1858 {
1867 /* If this is 'Null_Parameter, pass a zero even though we are
1868 dereferencing it. */
1873 BITS_PER_WORD))
1874 gnu_actual
1879 integer_zero_node),
1881 else
1883 }
1886 }
1890 NULL_TREE);
1892 /* If we return by passing a target, we emit the call and return the target
1893 as our result. */
1895 {
1897 *gnu_result_type_p
1900 }
1902 /* If it is a function call, the result is the call expression unless
1903 a target is specified, in which case we copy the result into the target
1904 and return the assignment statement. */
1906 {
1909 /* If the function returns an unconstrained array or by reference,
1910 we have to de-dereference the pointer. */
1918 else
1922 }
1924 /* If this is the case where the GNAT tree contains a procedure call
1925 but the Ada procedure has copy in copy out parameters, the special
1926 parameter passing mechanism must be used. */
1928 {
1929 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
1930 in copy out parameters. */
1935 {
1936 tree gnu_name;
1941 /* If any of the names had side-effects, ensure they are all
1942 evaluated before the call. */
1948 }
1952 else
1959 /* If we are dealing with a copy in copy out parameter, we must
1960 retrieve its value from the record returned in the call. */
1966 || (DECL_BY_DESCRIPTOR_P
1969 {
1970 /* Get the value to assign to this OUT or IN OUT parameter. It is
1971 either the result of the function if there is only a single such
1972 parameter or the appropriate field from the record returned. */
1973 tree gnu_result
1980 /* If the actual is a conversion, get the inner expression, which
1981 will be the real destination, and convert the result to the
1982 type of the actual parameter. */
1983 tree gnu_actual
1986 /* If the result is a padded type, remove the padding. */
1991 gnu_result);
1993 /* If the result is a type conversion, do it. */
1995 gnu_result
1996 = convert_with_check
2004 gnu_result,
2006 else
2007 {
2015 }
2023 }
2024 }
2025 else
2026 {
2029 }
2033 }
2034 \f
2035 /* Subroutine of gnat_to_gnu to translate gnat_node, an
2036 N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */
2038 static tree
2040 {
2043 /* If just annotating, ignore all EH and cleanups. */
2047 bool setjmp_longjmp
2053 tree gnu_result;
2054 tree gnu_expr;
2055 Node_Id gnat_temp;
2057 /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes
2058 and we have our own SJLJ mechanism. To call the GCC mechanism, we call
2059 add_cleanup, and when we leave the binding, end_stmt_group will create
2060 the TRY_FINALLY_EXPR.
2062 ??? The region level calls down there have been specifically put in place
2063 for a ZCX context and currently the order in which things are emitted
2064 (region/handlers) is different from the SJLJ case. Instead of putting
2065 other calls with different conditions at other places for the SJLJ case,
2066 it seems cleaner to reorder things for the SJLJ case and generalize the
2067 condition to make it not ZCX specific.
2069 If there are any exceptions or cleanup processing involved, we need an
2070 outer statement group (for Setjmp_Longjmp) and binding level. */
2072 {
2075 }
2077 /* If we are to call a function when exiting this block add a cleanup
2078 to the binding level we made above. */
2082 /* If using setjmp_longjmp, make the variables for the setjmp buffer and save
2083 area for address of previous buffer. Do this first since we need to have
2084 the setjmp buf known for any decls in this block. */
2086 {
2091 gnat_node);
2099 /* When we exit this block, restore the saved value. */
2101 }
2103 /* Now build the tree for the declarations and statements inside this block.
2104 If this is SJLJ, set our jmp_buf as the current buffer. */
2110 gnu_jmpbuf_decl)));
2116 /* Generate code for each statement in the block. */
2124 /* Now generate code for the two exception models, if either is relevant for
2125 this block. */
2127 {
2129 tree gnu_handler;
2131 /* Make a binding level for the exception handling declarations and code
2132 and set up gnu_except_ptr_stack for the handlers to use. */
2138 NULL_TREE,
2143 /* Generate code for each handler. The N_Exception_Handler case does the
2144 real work and returns a COND_EXPR for each handler, which we chain
2145 together here. */
2148 {
2151 /* If this is the first one, set it as the outer one. Otherwise,
2152 point the "else" part of the previous handler to us. Then point
2153 to our "else" part. */
2156 else
2160 }
2162 /* If none of the exception handlers did anything, re-raise but do not
2163 defer abortion. */
2170 else
2173 /* End the binding level dedicated to the exception handlers and get the
2174 whole statement group. */
2179 /* If the setjmp returns 1, we restore our incoming longjmp value and
2180 then check the handlers. */
2183 gnu_jmpsave_decl),
2184 gnat_node);
2188 /* This block is now "if (setjmp) ... <handlers> else <block>". */
2190 (build_call_1_expr
2193 gnu_jmpbuf_decl))),
2195 }
2197 {
2198 tree gnu_handlers;
2200 /* First make a block containing the handlers. */
2208 /* Now make the TRY_CATCH_EXPR for the block. */
2211 }
2212 else
2215 /* Now close our outer block, if we had to make one. */
2217 {
2221 }
2224 }
2225 \f
2226 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2227 to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp
2228 exception handling. */
2230 static tree
2232 {
2233 /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make
2234 an "if" statement to select the proper exceptions. For "Others", exclude
2235 exceptions where Handled_By_Others is nonzero unless the All_Others flag
2236 is set. For "Non-ada", accept an exception if "Lang" is 'V'. */
2239 Node_Id gnat_temp;
2243 {
2244 tree this_choice;
2247 {
2250 else
2251 this_choice
2252 = build_binary_op
2254 convert
2256 build_component_ref
2257 (build_unary_op
2262 integer_zero_node);
2263 }
2267 {
2269 tree gnu_expr;
2271 /* Exception may be a renaming. Recover original exception which is
2272 the one elaborated and registered. */
2278 this_choice
2279 = build_binary_op
2284 /* If this is the distinguished exception "Non_Ada_Error" (and we are
2285 in VMS mode), also allow a non-Ada exception (a VMS condition) t
2286 match. */
2288 {
2289 tree gnu_comp
2290 = build_component_ref
2295 this_choice
2296 = build_binary_op
2300 this_choice);
2301 }
2302 }
2303 else
2308 }
2311 }
2312 \f
2313 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2314 to a GCC tree, which is returned. This is the variant for ZCX. */
2316 static tree
2318 {
2320 tree gnu_expr;
2321 tree gnu_etype;
2322 tree gnu_current_exc_ptr;
2323 tree gnu_incoming_exc_ptr;
2324 Node_Id gnat_temp;
2326 /* We build a TREE_LIST of nodes representing what exception types this
2327 handler can catch, with special cases for others and all others cases.
2329 Each exception type is actually identified by a pointer to the exception
2330 id, or to a dummy object for "others" and "all others".
2332 Care should be taken to ensure that the control flow impact of "others"
2333 and "all others" is known to GCC. lang_eh_type_covers is doing the trick
2334 currently. */
2337 {
2339 {
2340 tree gnu_expr
2343 gnu_etype
2345 }
2348 {
2351 /* Exception may be a renaming. Recover original exception which is
2352 the one elaborated and registered. */
2359 /* The Non_Ada_Error case for VMS exceptions is handled
2360 by the personality routine. */
2361 }
2362 else
2365 /* The GCC interface expects NULL to be passed for catch all handlers, so
2366 it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype
2367 is integer_zero_node. It would not work, however, because GCC's
2368 notion of "catch all" is stronger than our notion of "others". Until
2369 we correctly use the cleanup interface as well, doing that would
2370 prevent the "all others" handlers from being seen, because nothing
2371 can be caught beyond a catch all from GCC's point of view. */
2373 }
2378 /* Expand a call to the begin_handler hook at the beginning of the handler,
2379 and arrange for a call to the end_handler hook to occur on every possible
2380 exit path.
2382 The hooks expect a pointer to the low level occurrence. This is required
2383 for our stack management scheme because a raise inside the handler pushes
2384 a new occurrence on top of the stack, which means that this top does not
2385 necessarily match the occurrence this handler was dealing with.
2387 The EXC_PTR_EXPR object references the exception occurrence being
2388 propagated. Upon handler entry, this is the exception for which the
2389 handler is triggered. This might not be the case upon handler exit,
2390 however, as we might have a new occurrence propagated by the handler's
2391 body, and the end_handler hook called as a cleanup in this context.
2393 We use a local variable to retrieve the incoming value at handler entry
2394 time, and reuse it to feed the end_handler hook's argument at exit. */
2399 gnat_node);
2402 gnu_incoming_exc_ptr),
2403 gnat_node);
2410 }
2411 \f
2412 /* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */
2414 static void
2416 {
2417 /* Make the decl for the elaboration procedure. */
2422 tree gnu_elab_proc_decl
2423 = create_subprog_decl
2427 gnat_unit_entity);
2437 /* For a body, first process the spec if there is one. */
2446 {
2453 }
2459 /* Process any pragmas and actions following the unit. */
2463 /* Save away what we've made so far and record this potential elaboration
2464 procedure. */
2474 /* Generate elaboration code for this unit, if necessary, and say whether
2475 we did or not. */
2478 /* Generate functions to call static constructors and destructors
2479 for targets that do not support .ctors/.dtors sections. These
2480 functions have magic names which are detected by collect2. */
2486 }
2487 \f
2488 /* This function is the driver of the GNAT to GCC tree transformation
2489 process. It is the entry point of the tree transformer. GNAT_NODE is the
2490 root of some GNAT tree. Return the root of the corresponding GCC tree.
2491 If this is an expression, return the GCC equivalent of the expression. If
2492 it is a statement, return the statement. In the case when called for a
2493 statement, it may also add statements to the current statement group, in
2494 which case anything it returns is to be interpreted as occurring after
2495 anything `it already added. */
2497 tree
2499 {
2503 tree gnu_expr;
2505 Node_Id gnat_temp;
2507 /* Save node number for error message and set location information. */
2515 /* If this node is a non-static subexpression and we are only
2516 annotating types, make this into a NULL_EXPR. */
2524 /* If this is a Statement and we are at top level, it must be part of the
2525 elaboration procedure, so mark us as being in that procedure and push our
2526 context.
2528 If we are in the elaboration procedure, check if we are violating a a
2529 No_Elaboration_Code restriction by having a statement there. */
2540 {
2542 {
2547 }
2549 /* Don't check for a possible No_Elaboration_Code restriction violation
2550 on N_Handled_Sequence_Of_Statements, as we want to signal an error on
2551 every nested real statement instead. This also avoids triggering
2552 spurious errors on dummy (empty) sequences created by the front-end
2553 for package bodies in some cases. */
2558 }
2561 {
2562 /********************************/
2563 /* Chapter 2: Lexical Elements: */
2564 /********************************/
2574 {
2575 tree gnu_type;
2577 /* Get the type of the result, looking inside any padding and
2578 justified modular types. Then get the value in that type. */
2587 /* If the result overflows (meaning it doesn't fit in its base type),
2588 abort. We would like to check that the value is within the range
2589 of the subtype, but that causes problems with subtypes whose usage
2590 will raise Constraint_Error and with biased representation, so
2591 we don't. */
2593 }
2597 /* If a Entity is present, it means that this was one of the
2598 literals in a user-defined character type. In that case,
2599 just return the value in the CONST_DECL. Otherwise, use the
2600 character code. In that case, the base type should be an
2601 INTEGER_TYPE, but we won't bother checking for that. */
2605 else
2606 gnu_result
2607 = force_fit_type
2608 (build_int_cst
2614 /* If this is of a fixed-point type, the value we want is the
2615 value of the corresponding integer. */
2617 {
2620 gnu_result_type);
2622 }
2624 /* We should never see a Vax_Float type literal, since the front end
2625 is supposed to transform these using appropriate conversions */
2629 else
2630 {
2635 /* If the real value is zero, so is the result. Otherwise,
2636 convert it to a machine number if it isn't already. That
2637 forces BASE to 0 or 2 and simplifies the rest of our logic. */
2640 else
2641 {
2643 ur_realval
2647 gnu_result
2650 /* If we have a base of zero, divide by the denominator.
2651 Otherwise, the base must be 2 and we scale the value, which
2652 we know can fit in the mantissa of the type (hence the use
2653 of that type above). */
2655 gnu_result
2658 gnu_result,
2660 gnu_result_type));
2661 else
2662 {
2663 REAL_VALUE_TYPE tmp;
2669 }
2670 }
2672 /* Now see if we need to negate the result. Do it this way to
2673 properly handle -0. */
2675 gnu_result
2677 gnu_result);
2678 }
2685 {
2691 /* Build the string with the characters in the literal. Note
2692 that Ada strings are 1-origin. */
2696 /* Put a null at the end of the string in case it's in a context
2697 where GCC will want to treat it as a C string. */
2702 /* Strings in GCC don't normally have types, but we want
2703 this to not be converted to the array type. */
2705 }
2706 else
2707 {
2708 /* Build a list consisting of each character, then make
2709 the aggregate. */
2717 {
2718 gnu_list
2723 gnu_list);
2727 }
2729 gnu_result
2731 }
2738 /**************************************/
2739 /* Chapter 3: Declarations and Types: */
2740 /**************************************/
2757 /* If we are just annotating types and this object has an unconstrained
2758 or task type, don't elaborate it. */
2769 && (!type_annotate_only
2771 {
2776 /* If this object has its elaboration delayed, we must force
2777 evaluation of GNU_EXPR right now and save it for when the object
2778 is frozen. */
2780 {
2783 gnu_expr
2788 else
2792 }
2793 }
2794 else
2807 /* Don't do anything if this renaming is handled by the front end or if
2808 we are just annotating types and this object has a composite or task
2809 type, don't elaborate it. We return the result in case it has any
2810 SAVE_EXPRs in it that need to be evaluated here. */
2812 && ! (type_annotate_only
2816 gnu_result
2819 else
2832 /* These are fully handled in the front end. */
2836 /*************************************/
2837 /* Chapter 4: Names and Expressions: */
2838 /*************************************/
2847 {
2849 tree gnu_type;
2857 /* If we got a padded type, remove it too. */
2860 gnu_array_object
2862 gnu_array_object);
2866 /* First compute the number of dimensions of the array, then
2867 fill the expression array, the order depending on whether
2868 this is a Convention_Fortran array or not. */
2873 ;
2882 else
2890 {
2896 gnu_expr
2897 = emit_index_check
2904 }
2905 }
2911 {
2912 tree gnu_type;
2918 /* Do any implicit dereferences of the prefix and do any needed
2919 range check. */
2924 {
2925 /* Get the bounds of the slice. */
2926 tree gnu_index_type
2932 /* Check to see that the minimum slice value is in range */
2933 gnu_expr_l
2934 = emit_index_check
2939 /* Check to see that the maximum slice value is in range */
2940 gnu_expr_h
2941 = emit_index_check
2946 /* Derive a good type to convert everything too */
2949 /* Build a compound expression that does the range checks */
2950 gnu_expr
2955 /* Build a conditional expression that returns the range checks
2956 expression if the slice range is not null (max >= min) or
2957 returns the min if the slice range is null */
2958 gnu_expr
2962 gnu_max_expr),
2964 gnu_min_expr)),
2966 }
2967 else
2972 }
2976 {
2980 tree gnu_field;
2984 {
2989 }
2993 /* For discriminant references in tagged types always substitute the
2994 corresponding discriminant as the actual selected component. */
3000 /* For discriminant references of untagged types always substitute the
3001 corresponding stored discriminant. */
3006 /* Handle extracting the real or imaginary part of a complex.
3007 The real part is the first field and the imaginary the last. */
3013 else
3014 {
3017 /* If there are discriminants, the prefix might be
3018 evaluated more than once, which is a problem if it has
3019 side-effects. */
3026 gnu_result
3030 }
3034 }
3038 {
3039 /* The attribute designator (like an enumeration value). */
3042 /* The Elab_Spec and Elab_Body attributes are special in that
3043 Prefix is a unit, not an object with a GCC equivalent. Similarly
3044 for Elaborated, since that variable isn't otherwise known. */
3048 attribute == Attr_Elab_Body
3051 gnat_node));
3054 }
3058 /* Like 'Access as far as we are concerned. */
3066 {
3067 tree gnu_aggr_type;
3069 /* ??? It is wrong to evaluate the type now, but there doesn't
3070 seem to be any other practical way of doing it. */
3074 gnu_aggr_type = gnu_result_type
3079 gnu_aggr_type
3087 {
3088 /* The first element is the discrimant, which we ignore. The
3089 next is the field we're building. Convert the expression
3090 to the type of the field and then to the union type. */
3091 Node_Id gnat_assoc
3094 tree gnu_field_type
3099 }
3102 gnu_result
3104 gnu_aggr_type);
3107 gnu_aggr_type,
3110 gnu_result
3111 = build_binary_op
3116 (Next
3118 else
3122 }
3132 /* Get the operand expression. */
3136 gnu_result
3148 /* If the result is a pointer type, see if we are improperly
3149 converting to a stricter alignment. */
3153 {
3159 post_error_ne_tree_2
3163 }
3171 {
3174 tree gnu_low;
3175 tree gnu_high;
3177 /* GNAT_RANGE is either an N_Range node or an identifier
3178 denoting a subtype. */
3180 {
3183 }
3186 {
3191 }
3192 else
3197 /* If LOW and HIGH are identical, perform an equality test.
3198 Otherwise, ensure that GNU_OBJECT is only evaluated once
3199 and perform a full range test. */
3203 else
3204 {
3206 gnu_result
3212 }
3216 }
3224 ? RDIV_EXPR
3231 /* These can either be operations on booleans or on modular types.
3232 Fall through for boolean types since that's the way GNU_CODES is
3233 set up. */
3235 Modular_Integer_Kind))
3236 {
3237 enum tree_code code
3248 }
3250 /* ... fall through ... */
3262 {
3264 tree gnu_type;
3270 /* If this is a comparison operator, convert any references to
3271 an unconstrained array value into a reference to the
3272 actual array. */
3274 {
3277 }
3279 /* If the result type is a private type, its full view may be a
3280 numeric subtype. The representation we need is that of its base
3281 type, given that it is the result of an arithmetic operation. */
3283 gnu_type = gnu_result_type
3286 /* If this is a shift whose count is not guaranteed to be correct,
3287 we need to adjust the shift count. */
3290 {
3292 tree gnu_max_shift
3300 gnu_rhs
3301 = build_binary_op
3304 gnu_count_type,
3305 gnu_max_shift,
3307 integer_one_node)),
3308 gnu_rhs);
3309 }
3311 /* For right shifts, the type says what kind of shift to do,
3312 so we may need to choose a different type. */
3321 {
3324 }
3328 /* If this is a logical shift with the shift count not verified,
3329 we must return zero if it is too large. We cannot compensate
3330 above in this case. */
3334 gnu_result
3335 = build_cond_expr
3338 gnu_rhs,
3342 gnu_result);
3343 }
3347 {
3350 tree gnu_false
3357 }
3366 /* This case can apply to a boolean or a modular type.
3367 Fall through for a boolean operand since GNU_CODES is set
3368 up to handle this. */
3370 {
3374 gnu_expr);
3376 }
3378 /* ... fall through ... */
3385 else
3394 {
3396 tree gnu_type;
3401 /* The Expression operand can either be an N_Identifier or
3402 Expanded_Name, which must represent a type, or a
3403 N_Qualified_Expression, which contains both the object type and an
3404 initial value for the object. */
3409 {
3410 Entity_Id gnat_desig_type
3422 {
3425 }
3426 else
3427 {
3433 }
3434 }
3435 else
3442 ignore_init_type);
3443 }
3446 /***************************/
3447 /* Chapter 5: Statements: */
3448 /***************************/
3460 /* Get the LHS and RHS of the statement and convert any reference to an
3461 unconstrained array into a reference to the underlying array.
3462 If we are not to do range checking and the RHS is an N_Function_Call,
3463 pass the LHS to the call function. */
3466 /* If the type has a size that overflows, convert this into raise of
3467 Storage_Error: execution shouldn't have gotten here anyway. */
3475 else
3476 {
3477 gnu_rhs
3480 /* If range check is needed, emit code to generate it */
3484 gnu_result
3486 }
3490 {
3493 /* Make the outer COND_EXPR. Avoid non-determinism. */
3502 /* Now make a COND_EXPR for each of the "else if" parts. Put each
3503 into the previous "else" part and point to where to put any
3504 outer "else". Also avoid non-determinism. */
3508 {
3518 }
3521 }
3545 gnu_result
3555 {
3556 /* The gnu function type of the subprogram currently processed. */
3558 /* The return value from the subprogram. */
3560 /* The place to put the return value. */
3561 tree gnu_lhs;
3563 /* If we are dealing with a "return;" from an Ada procedure with
3564 parameters passed by copy in copy out, we need to return a record
3565 containing the final values of these parameters. If the list
3566 contains only one entry, return just that entry.
3568 For a full description of the copy in copy out parameter mechanism,
3569 see the part of the gnat_to_gnu_entity routine dealing with the
3570 translation of subprograms.
3572 But if we have a return label defined, convert this into
3573 a branch to that label. */
3576 {
3580 }
3583 {
3587 else
3588 gnu_ret_val
3591 }
3593 /* If the Ada subprogram is a function, we just need to return the
3594 expression. If the subprogram returns an unconstrained
3595 array, we have to allocate a new version of the result and
3596 return it. If we return by reference, return a pointer. */
3599 {
3600 /* If the current function returns by target pointer and we
3601 are doing a call, pass that target to the call. */
3604 {
3605 gnu_lhs
3610 }
3611 else
3612 {
3616 /* The original return type was unconstrained so dereference
3617 the TARGET pointer in the actual return value's type. */
3618 gnu_lhs
3621 else
3624 /* Do not remove the padding from GNU_RET_VAL if the inner
3625 type is self-referential since we want to allocate the fixed
3626 size in that case. */
3630 && (TYPE_IS_PADDING_P
3632 && (CONTAINS_PLACEHOLDER_P
3638 gnu_ret_val
3642 {
3645 /* We have two cases: either the function returns with
3646 depressed stack or not. If not, we allocate on the
3647 secondary stack. If so, we allocate in the stack frame.
3648 if no copy is needed, the front end will set By_Ref,
3649 which we handle in the case above. */
3651 gnu_ret_val
3653 gnu_ret_val,
3656 else
3657 gnu_ret_val
3659 gnu_ret_val,
3664 }
3665 }
3666 }
3667 else
3668 /* If the Ada subprogram is a regular procedure, just return. */
3672 {
3678 }
3681 }
3689 /****************************/
3690 /* Chapter 6: Subprograms: */
3691 /****************************/
3694 /* Unless there is a freeze node, declare the subprogram. We consider
3695 this a "definition" even though we're not generating code for
3696 the subprogram because we will be making the corresponding GCC
3697 node here. */
3706 /* This subprogram doesn't exist for code generation purposes, but we
3707 have to elaborate the types of any parameters, unless they are
3708 imported types (nothing to generate in this case). */
3721 /* For a child unit identifier go up a level to get the
3722 specification. We get this when we try to find the spec of
3723 a child unit package that is the compilation unit being compiled. */
3737 /*************************/
3738 /* Chapter 7: Packages: */
3739 /*************************/
3755 /* If this is the body of a generic package - do nothing */
3757 {
3760 }
3771 /*********************************/
3772 /* Chapter 8: Visibility Rules: */
3773 /*********************************/
3777 /* Nothing to do here - but these may appear in list of declarations */
3781 /***********************/
3782 /* Chapter 9: Tasks: */
3783 /***********************/
3794 /***********************************************************/
3795 /* Chapter 10: Program Structure and Compilation Issues: */
3796 /***********************************************************/
3800 /* This is not called for the main unit, which is handled in function
3801 gigi above. */
3813 /* Simply process whatever unit is being inserted. */
3821 /***************************/
3822 /* Chapter 11: Exceptions: */
3823 /***************************/
3826 /* If there is an At_End procedure attached to this node, and the EH
3827 mechanism is SJLJ, we must have at least a corresponding At_End
3828 handler, unless the No_Exception_Handlers restriction is set. */
3843 else
3848 /*******************************/
3849 /* Chapter 12: Generic Units: */
3850 /*******************************/
3860 /* These nodes can appear on a declaration list but there is nothing to
3861 to be done with them. */
3865 /***************************************************/
3866 /* Chapter 13: Representation Clauses and */
3867 /* Implementation-Dependent Features: */
3868 /***************************************************/
3874 /* The only one we need deal with is for 'Address. For the others, SEM
3875 puts the information elsewhere. We need only deal with 'Address
3876 if the object has a Freeze_Node (which it never will currently). */
3881 /* Get the value to use as the address and save it as the
3882 equivalent for GNAT_TEMP. When the object is frozen,
3883 gnat_to_gnu_entity will do the right thing. */
3891 /* We do nothing with these. SEM puts the information elsewhere. */
3897 {
3903 /* First process inputs, then outputs, then clobbers. */
3906 {
3911 gnu_input_list
3914 }
3918 {
3923 gnu_output_list
3926 }
3930 gnu_clobber_list
3933 gnu_clobber_list);
3941 }
3942 else
3947 /***************************************************/
3948 /* Added Nodes */
3949 /***************************************************/
3967 {
3970 tree gnu_obj_type;
3972 tree gnu_obj_size;
3975 /* If this is a thin pointer, we must dereference it to create
3976 a fat pointer, then go back below to a thin pointer. The
3977 reason for this is that we need a fat pointer someplace in
3978 order to properly compute the size. */
3982 gnu_ptr));
3984 /* If this is an unconstrained array, we know the object must
3985 have been allocated with the template in front of the object.
3986 So pass the template address, but get the total size. Do this
3987 by converting to a thin pointer. */
3989 gnu_ptr
3991 (TYPE_OBJECT_RECORD_TYPE
3993 gnu_ptr);
3998 {
4002 gnu_actual_obj_type
4004 gnu_actual_obj_type,
4006 }
4007 else
4015 {
4018 tree gnu_byte_offset
4025 }
4030 gnat_node);
4031 }
4038 {
4041 }
4044 gnu_result
4047 /* If the type is VOID, this is a statement, so we need to
4048 generate the code for the call. Handle a Condition, if there
4049 is one. */
4051 {
4058 }
4059 else
4064 /* If the result is a pointer type, see if we are either converting
4065 from a non-pointer or from a pointer to a type with a different
4066 alias set and warn if so. If the result defined in the same unit as
4067 this unchecked conversion, we can allow this because we can know to
4068 make that type have alias set 0. */
4069 {
4080 {
4081 post_error_ne
4084 post_error
4086 gnat_node);
4087 post_error_ne
4090 }
4092 /* The No_Strict_Aliasing flag is not propagated to the back-end for
4093 fat pointers so unconditionally warn in problematic cases. */
4095 {
4096 tree array_type
4103 {
4104 post_error_ne
4107 post_error
4109 gnat_node);
4110 }
4111 }
4112 }
4125 }
4127 /* If we pushed our level as part of processing the elaboration routine,
4128 pop it back now. */
4130 {
4135 }
4137 /* Set the location information into the result. Note that we may have
4138 no result if we tried to build a CALL_EXPR node to a procedure with
4139 no side-effects and optimization is enabled. */
4143 /* If we're supposed to return something of void_type, it means we have
4144 something we're elaborating for effect, so just return. */
4148 /* If the result is a constant that overflows, raise constraint error. */
4151 {
4154 gnu_result
4157 }
4159 /* If our result has side-effects and is of an unconstrained type,
4160 make a SAVE_EXPR so that we can be sure it will only be referenced
4161 once. Note we must do this before any conversions. */
4167 /* Now convert the result to the proper type. If the type is void or if
4168 we have no result, return error_mark_node to show we have no result.
4169 If the type of the result is correct or if we have a label (which doesn't
4170 have any well-defined type), return our result. Also don't do the
4171 conversion if the "desired" type involves a PLACEHOLDER_EXPR in its size
4172 since those are the cases where the front end may have the type wrong due
4173 to "instantiating" the unconstrained record with discriminant values
4174 or if this is a FIELD_DECL. If this is the Name of an assignment
4175 statement or a parameter of a procedure call, return what we have since
4176 the RHS has to be converted to our type there in that case, unless
4177 GNU_RESULT_TYPE has a simpler size. Similarly, if the two types are
4178 record types with the same name, the expression type has integral mode,
4179 and GNU_RESULT_TYPE BLKmode, don't convert. This will be the case when
4180 we are converting from a packable type to its actual type and we need
4181 those conversions to be NOPs in order for assignments into these types to
4182 work properly if the inner object is a bitfield and hence can't have
4183 its address taken. Finally, don't convert integral types that are the
4184 operand of an unchecked conversion since we need to ignore those
4185 conversions (for 'Valid). Otherwise, convert the result to the proper
4186 type. */
4206 && (CONTAINS_PLACEHOLDER_P
4210 {
4211 /* In this case remove padding only if the inner object is of
4212 self-referential size: in that case it must be an object of
4213 unconstrained type with a default discriminant. In other cases,
4214 we want to avoid copying too much data. */
4221 gnu_result);
4222 }
4238 {
4239 /* Remove any padding record, but do nothing more in this case. */
4243 gnu_result);
4244 }
4252 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RESULT. */
4259 }
4260 \f
4261 /* Record the current code position in GNAT_NODE. */
4263 static void
4265 {
4270 }
4272 /* Insert the code for GNAT_NODE at the position saved for that node. */
4274 static void
4276 {
4279 }
4280 \f
4281 /* Start a new statement group chained to the previous group. */
4283 static void
4285 {
4288 /* First see if we can get one from the free list. */
4291 else
4297 }
4299 /* Add GNU_STMT to the current statement group. */
4301 void
4303 {
4306 /* If we're at top level, show everything in here is in use in case
4307 any of it is shared by a subprogram. */
4311 }
4313 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE. */
4315 void
4317 {
4321 }
4323 /* Add a declaration statement for GNU_DECL to the current statement group.
4324 Get SLOC from Entity_Id. */
4326 void
4328 {
4329 tree gnu_stmt;
4331 /* If this is a variable that Gigi is to ignore, we may have been given
4332 an ERROR_MARK. So test for it. We also might have been given a
4333 reference for a renaming. So only do something for a decl. Also
4334 ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */
4340 /* If we are global, we don't want to actually output the DECL_EXPR for
4341 this decl since we already have evaluated the expressions in the
4342 sizes and positions as globals and doing it again would be wrong.
4343 But we do have to mark everything as used. */
4347 else
4348 {
4352 {
4356 }
4357 }
4359 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set,
4360 there are two cases we need to handle here. */
4362 {
4366 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set
4367 and decl has a padded type, convert it to the unpadded type so the
4368 assignment is done properly. */
4371 gnu_lhs
4374 /* Otherwise, if this is going into memory and the initializer isn't
4375 valid for the assembler and loader. Gimplification could do this,
4376 but would be run too late if -fno-unit-at-a-time. */
4383 {
4384 tree gnu_assign_stmt
4393 }
4394 }
4395 }
4397 /* Utility function to mark nodes with TREE_VISITED and types as having their
4398 sized gimplified. Called from walk_tree. We use this to indicate all
4399 variable sizes and positions in global types may not be shared by any
4400 subprogram. */
4402 static tree
4404 {
4408 /* Don't mark a dummy type as visited because we want to mark its sizes
4409 and fields once it's filled in. */
4417 }
4419 /* Likewise, but to mark as unvisited. */
4421 static tree
4424 {
4428 }
4430 /* Add GNU_CLEANUP, a cleanup action, to the current code group. */
4432 static void
4434 {
4436 }
4438 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */
4440 void
4442 {
4445 }
4447 /* Return code corresponding to the current code group. It is normally
4448 a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
4449 BLOCK or cleanups were set. */
4451 static tree
4453 {
4457 /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there
4458 are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK,
4459 make a BIND_EXPR. Note that we nest in that because the cleanup may
4460 reference variables in the block. */
4472 /* Remove this group from the stack and add it to the free list. */
4478 }
4480 /* Add a list of statements from GNAT_LIST, a possibly-empty list of
4481 statements.*/
4483 static void
4485 {
4486 Node_Id gnat_node;
4492 }
4494 /* Build a tree from GNAT_LIST, a possibly-empty list of statements.
4495 If BINDING_P is true, push and pop a binding level around the list. */
4497 static tree
4499 {
4509 }
4510 \f
4511 /* Push and pop routines for stacks. We keep a free list around so we
4512 don't waste tree nodes. */
4514 static void
4516 {
4520 {
4525 }
4526 else
4530 }
4532 static void
4534 {
4540 }
4541 \f
4542 /* GNU_STMT is a statement. We generate code for that statement. */
4544 void
4546 {
4547 #if 0
4549 #endif
4552 {
4553 #if 0
4555 /* First write a volatile ASM_INPUT to prevent anything from being
4556 moved. */
4562 modifier);
4565 #endif
4569 }
4570 }
4571 \f
4572 /* Generate GIMPLE in place for the expression at *EXPR_P. */
4574 int
4576 {
4578 tree op;
4584 {
4586 /* If this is for a scalar, just make a VAR_DECL for it. If for
4587 an aggregate, get a null pointer of the appropriate type and
4588 dereference it. */
4592 integer_zero_node));
4593 else
4594 {
4597 }
4603 /* We should only do this if we are just elaborating for side-effects,
4604 but we can't know that yet. */
4611 /* If we're taking the address of a constant CONSTRUCTOR, force it to
4612 be put into static memory. We know it's going to be readonly given
4613 the semantics we have and it's required to be static memory in
4614 the case when the reference is in an elaboration procedure. */
4616 {
4627 }
4629 /* Otherwise, if we are taking the address of something that is neither
4630 reference, declaration, or constant, make a variable for the operand
4631 here and then take its address. If we don't do it this way, we may
4632 confuse the gimplifier because it needs to know the variable is
4633 addressable at this point. This duplicates code in
4634 internal_get_tmp_var, which is unfortunate. */
4638 {
4651 }
4656 /* We have a kludge here. If the FIELD_DECL is from a fat pointer and is
4657 from an early dummy type, replace it with the proper FIELD_DECL. */
4660 {
4664 }
4666 /* ... fall through ... */
4670 }
4671 }
4673 /* Generate GIMPLE in place for the statement at *STMT_P. */
4675 static enum gimplify_status
4677 {
4681 {
4691 {
4695 /* Set to emit the statements of the loop. */
4698 /* We first emit the start label and then a conditional jump to
4699 the end label if there's a top condition, then the body of the
4700 loop, then a conditional branch to the end label, then the update,
4701 if any, and finally a jump to the start label and the definition
4702 of the end label. */
4704 gnu_start_label),
4705 stmt_p);
4712 void_type_node,
4713 gnu_end_label)),
4714 stmt_p);
4723 void_type_node,
4724 gnu_end_label)),
4725 stmt_p);
4731 gnu_start_label),
4732 stmt_p);
4734 gnu_end_label),
4735 stmt_p);
4737 }
4740 /* Build a statement to jump to the corresponding end label, then
4741 see if it needs to be conditional. */
4750 }
4751 }
4752 \f
4753 /* Force references to each of the entities in packages GNAT_NODE with's
4754 so that the debugging information for all of them are identical
4755 in all clients. Operate recursively on anything it with's, but check
4756 that we aren't elaborating something more than once. */
4758 /* The reason for this routine's existence is two-fold.
4759 First, with some debugging formats, notably MDEBUG on SGI
4760 IRIX, the linker will remove duplicate debugging information if two
4761 clients have identical debugguing information. With the normal scheme
4762 of elaboration, this does not usually occur, since entities in with'ed
4763 packages are elaborated on demand, and if clients have different usage
4764 patterns, the normal case, then the order and selection of entities
4765 will differ. In most cases however, it seems that linkers do not know
4766 how to eliminate duplicate debugging information, even if it is
4767 identical, so the use of this routine would increase the total amount
4768 of debugging information in the final executable.
4770 Second, this routine is called in type_annotate mode, to compute DDA
4771 information for types in withed units, for ASIS use */
4773 static void
4775 {
4778 /* Process each unit only once. As we trace the context of all relevant
4779 units transitively, including generic bodies, we may encounter the
4780 same generic unit repeatedly */
4785 /* Save entities in all context units. A body may have an implicit_with
4786 on its own spec, if the context includes a child unit, so don't save
4787 the spec twice. */
4795 {
4799 {
4816 }
4818 {
4819 Node_Id gnat_body
4822 /* Retrieve compilation unit node of generic body. */
4827 /* If body is available, elaborate its context. */
4830 }
4831 }
4835 }
4836 \f
4837 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
4839 static void
4841 {
4843 tree gnu_old;
4844 tree gnu_new;
4845 tree gnu_init
4850 /* If this is a package, need to generate code for the package. */
4852 {
4853 insert_code_for
4857 }
4859 /* Check for old definition after the above call. This Freeze_Node
4860 might be for one its Itypes. */
4861 gnu_old
4864 /* If this entity has an Address representation clause, GNU_OLD is the
4865 address, so discard it here. */
4869 /* Don't do anything for class-wide types they are always
4870 transformed into their root type. */
4876 /* Don't do anything for subprograms that may have been elaborated before
4877 their freeze nodes. This can happen, for example because of an inner call
4878 in an instance body, or a previous compilation of a spec for inlining
4879 purposes. */
4884 || (gnu_old
4889 /* If we have a non-dummy type old tree, we have nothing to do. Unless
4890 this is the public view of a private type whose full view was not
4891 delayed, this node was never delayed as it should have been.
4892 Also allow this to happen for concurrent types since we may have
4893 frozen both the Corresponding_Record_Type and this type. */
4897 {
4903 }
4905 /* Reset the saved tree, if any, and elaborate the object or type for real.
4906 If there is a full declaration, elaborate it and copy the type to
4907 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
4908 a class wide type or subtype. */
4910 {
4919 }
4923 {
4926 /* Propagate back-annotations from full view to partial view. */
4936 /* The above call may have defined this entity (the simplest example
4937 of this is when we have a private enumeral type since the bounds
4938 will have the public view. */
4944 }
4945 else
4948 /* If we've made any pointers to the old version of this type, we
4949 have to update them. */
4953 }
4954 \f
4955 /* Process the list of inlined subprograms of GNAT_NODE, which is an
4956 N_Compilation_Unit. */
4958 static void
4960 {
4961 Entity_Id gnat_entity;
4962 Node_Id gnat_body;
4964 /* If we can inline, generate RTL for all the inlined subprograms.
4965 Define the entity first so we set DECL_EXTERNAL. */
4970 {
4974 {
4975 /* ??? This really should always be Present. */
4979 gnat_body
4981 }
4984 {
4987 }
4988 }
4989 }
4990 \f
4991 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
4992 We make two passes, one to elaborate anything other than bodies (but
4993 we declare a function if there was no spec). The second pass
4994 elaborates the bodies.
4996 GNAT_END_LIST gives the element in the list past the end. Normally,
4997 this is Empty, but can be First_Real_Statement for a
4998 Handled_Sequence_Of_Statements.
5000 We make a complete pass through both lists if PASS1P is true, then make
5001 the second pass over both lists if PASS2P is true. The lists usually
5002 correspond to the public and private parts of a package. */
5004 static void
5007 {
5009 Node_Id gnat_decl;
5019 {
5020 /* For package specs, we recurse inside the declarations,
5021 thus taking the two pass approach inside the boundary. */
5029 /* Similarly for any declarations in the actions of a
5030 freeze node. */
5032 {
5035 }
5037 /* Package bodies with freeze nodes get their elaboration deferred
5038 until the freeze node, but the code must be placed in the right
5039 place, so record the code position now. */
5047 (Corresponding_Spec
5050 record_code_position
5053 /* We defer most subprogram bodies to the second pass. */
5055 {
5057 {
5063 }
5064 }
5065 /* For bodies and stubs that act as their own specs, the entity
5066 itself must be elaborated in the first pass, because it may
5067 be used in other declarations. */
5069 {
5070 Node_Id gnat_subprog_id =
5077 }
5079 /* Concurrent stubs stand for the corresponding subprogram bodies,
5080 which are deferred like other bodies. */
5083 ;
5084 else
5086 }
5088 /* Here we elaborate everything we deferred above except for package bodies,
5089 which are elaborated at their freeze nodes. Note that we must also
5090 go inside things (package specs and freeze nodes) the first pass did. */
5096 {
5112 }
5113 }
5114 \f
5115 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
5116 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
5117 which we have to check. */
5119 static tree
5121 {
5127 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
5128 we can't do anything since we might be truncating the bounds. No
5129 check is needed in this case. */
5135 /* Checked expressions must be evaluated only once. */
5138 /* There's no good type to use here, so we might as well use
5139 integer_type_node. Note that the form of the check is
5140 (not (expr >= lo)) or (not (expr >= hi))
5141 the reason for this slightly convoluted form is that NaN's
5142 are not considered to be in range in the float case. */
5143 return emit_check
5145 invert_truthvalue
5149 invert_truthvalue
5153 gnu_high)))),
5155 }
5156 \f
5157 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
5158 which we are about to index, GNU_EXPR is the index expression to be
5159 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
5160 against which GNU_EXPR has to be checked. Note that for index
5161 checking we cannot use the emit_range_check function (although very
5162 similar code needs to be generated in both cases) since for index
5163 checking the array type against which we are checking the indeces
5164 may be unconstrained and consequently we need to retrieve the
5165 actual index bounds from the array object itself
5166 (GNU_ARRAY_OBJECT). The place where we need to do that is in
5167 subprograms having unconstrained array formal parameters */
5169 static tree
5171 tree gnu_expr,
5172 tree gnu_low,
5173 tree gnu_high)
5174 {
5175 tree gnu_expr_check;
5177 /* Checked expressions must be evaluated only once. */
5180 /* Must do this computation in the base type in case the expression's
5181 type is an unsigned subtypes. */
5184 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
5185 the object we are handling. */
5189 /* There's no good type to use here, so we might as well use
5190 integer_type_node. */
5191 return emit_check
5194 gnu_expr_check,
5196 gnu_low)),
5198 gnu_expr_check,
5200 gnu_high))),
5202 }
5203 \f
5204 /* GNU_COND contains the condition corresponding to an access, discriminant or
5205 range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if
5206 GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true.
5207 REASON is the code that says why the exception was raised. */
5209 static tree
5211 {
5212 tree gnu_call;
5213 tree gnu_result;
5217 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
5218 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
5219 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
5220 out. */
5224 gnu_expr));
5226 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
5227 protect it. Otherwise, show GNU_RESULT has no side effects: we
5228 don't need to evaluate it just for the check. */
5230 gnu_result
5232 else
5235 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
5236 we will repeatedly do the test. It would be nice if GCC was able
5237 to optimize this and only do it once. */
5239 }
5240 \f
5241 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
5242 overflow checks if OVERFLOW_P is nonzero and range checks if
5243 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
5244 If TRUNCATE_P is nonzero, do a float to integer conversion with
5245 truncation; otherwise round. */
5247 static tree
5250 {
5258 /* If we are not doing any checks, the output is an integral type, and
5259 the input is not a floating type, just do the conversion. This
5260 shortcut is required to avoid problems with packed array types
5261 and simplifies code in all cases anyway. */
5266 /* First convert the expression to its base type. This
5267 will never generate code, but makes the tests below much simpler.
5268 But don't do this if converting from an integer type to an unconstrained
5269 array type since then we need to get the bounds from the original
5270 (unpacked) type. */
5274 /* If overflow checks are requested, we need to be sure the result will
5275 fit in the output base type. But don't do this if the input
5276 is integer and the output floating-point. */
5279 {
5280 /* Ensure GNU_EXPR only gets evaluated once. */
5288 /* Convert the lower bounds to signed types, so we're sure we're
5289 comparing them properly. Likewise, convert the upper bounds
5290 to unsigned types. */
5304 /* Check each bound separately and only if the result bound
5305 is tighter than the bound on the input type. Note that all the
5306 types are base types, so the bounds must be constant. Also,
5307 the comparison is done in the base type of the input, which
5308 always has the proper signedness. First check for input
5309 integer (which means output integer), output float (which means
5310 both float), or mixed, in which case we always compare.
5311 Note that we have to do the comparison which would *fail* in the
5312 case of an error since if it's an FP comparison and one of the
5313 values is a NaN or Inf, the comparison will fail. */
5320 gnu_cond
5321 = invert_truthvalue
5324 gnu_out_lb)));
5332 gnu_cond
5334 invert_truthvalue
5336 gnu_input,
5338 gnu_out_ub))));
5342 CE_Overflow_Check_Failed);
5343 }
5345 /* Now convert to the result base type. If this is a non-truncating
5346 float-to-integer conversion, round. */
5349 {
5355 /* The following calculations depend on proper rounding to even
5356 of each arithmetic operation. In order to prevent excess
5357 precision from spoiling this property, use the widest hardware
5358 floating-point type.
5360 FIXME: For maximum efficiency, this should only be done for machines
5361 and types where intermediates may have extra precision. */
5364 /* FIXME: Should not have padding in the first place */
5369 /* Compute the exact value calc_type'Pred (0.5) at compile time. */
5373 half_minus_pred_half);
5376 /* If the input is strictly negative, subtract this value
5377 and otherwise add it from the input. For 0.5, the result
5378 is exactly between 1.0 and the machine number preceding 1.0
5379 (for calc_type). Since the last bit of 1.0 is even, this 0.5
5380 will round to 1.0, while all other number with an absolute
5381 value less than 0.5 round to 0.0. For larger numbers exactly
5382 halfway between integers, rounding will always be correct as
5383 the true mathematical result will be closer to the higher
5384 integer compared to the lower one. So, this constant works
5385 for all floating-point numbers.
5387 The reason to use the same constant with subtract/add instead
5388 of a positive and negative constant is to allow the comparison
5389 to be scheduled in parallel with retrieval of the constant and
5390 conversion of the input to the calc_type (if necessary).
5391 */
5398 gnu_add_pred_half
5400 gnu_subtract_pred_half
5404 }
5410 else
5413 /* Finally, do the range check if requested. Note that if the
5414 result type is a modular type, the range check is actually
5415 an overflow check. */
5423 }
5424 \f
5425 /* Return 1 if GNU_EXPR can be directly addressed. This is the case unless
5426 it is an expression involving computation or if it involves a reference
5427 to a bitfield or to a field not sufficiently aligned for its type. */
5429 static bool
5431 {
5433 {
5438 /* All DECLs are addressable: if they are in a register, we can force
5439 them to memory. */
5451 && (!STRICT_ALIGNMENT
5452 /* If the field was marked as "semantically" addressable
5453 in create_field_decl, we are guaranteed that it can
5454 be directly addressed. */
5456 /* Otherwise it can nevertheless be directly addressed
5457 if it has been sufficiently aligned in the record. */
5472 {
5473 /* This is addressable if we can avoid a copy. */
5487 }
5491 }
5492 }
5493 \f
5494 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
5495 a separate Freeze node exists, delay the bulk of the processing. Otherwise
5496 make a GCC type for GNAT_ENTITY and set up the correspondence. */
5498 void
5500 {
5501 tree gnu_old
5503 tree gnu_new;
5505 /* If we are to delay elaboration of this type, just do any
5506 elaborations needed for expressions within the declaration and
5507 make a dummy type entry for this node and its Full_View (if
5508 any) in case something points to it. Don't do this if it
5509 has already been done (the only way that can happen is if
5510 the private completion is also delayed). */
5516 {
5520 {
5529 }
5532 }
5534 /* If we saved away a dummy type for this node it means that this
5535 made the type that corresponds to the full type of an incomplete
5536 type. Clear that type for now and then update the type in the
5537 pointers. */
5539 {
5542 {
5543 /* If this was a withed access type, this is not an error
5544 and merely indicates we've already elaborated the type
5545 already. */
5548 }
5551 }
5553 /* Now fully elaborate the type. */
5557 /* If we have an old type and we've made pointers to this type,
5558 update those pointers. */
5563 /* If this is a record type corresponding to a task or protected type
5564 that is a completion of an incomplete type, perform a similar update
5565 on the type. */
5566 /* ??? Including protected types here is a guess. */
5571 {
5572 tree gnu_task_old
5582 }
5583 }
5584 \f
5585 /* GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate.
5586 GNU_TYPE is the GCC type of the corresponding record.
5588 Return a CONSTRUCTOR to build the record. */
5590 static tree
5592 {
5595 /* We test for GNU_FIELD being empty in the case where a variant
5596 was the last thing since we don't take things off GNAT_ASSOC in
5597 that case. We check GNAT_ASSOC in case we have a variant, but it
5598 has no fields. */
5602 {
5607 /* The expander is supposed to put a single component selector name
5608 in every record component association */
5611 /* Ignore fields that have Corresponding_Discriminants since we'll
5612 be setting that field in the parent. */
5617 /* Before assigning a value in an aggregate make sure range checks
5618 are done if required. Then convert to the type of the field. */
5624 /* Add the field and expression to the list. */
5626 }
5630 #ifdef ENABLE_CHECKING
5631 {
5632 tree gnu_field;
5634 /* Verify every enty in GNU_LIST was used. */
5637 }
5638 #endif
5641 }
5643 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
5644 is the first element of an array aggregate. It may itself be an
5645 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
5646 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
5647 of the array component. It is needed for range checking. */
5649 static tree
5651 Entity_Id gnat_component_type)
5652 {
5655 tree gnu_expr;
5658 {
5659 /* If the expression is itself an array aggregate then first build the
5660 innermost constructor if it is part of our array (multi-dimensional
5661 case). */
5668 gnat_component_type);
5669 else
5670 {
5673 /* before assigning the element to the array make sure it is
5674 in range */
5677 }
5679 gnu_expr_list
5681 gnu_expr_list);
5684 }
5687 }
5688 \f
5689 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
5690 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
5691 of the associations that are from RECORD_TYPE. If we see an internal
5692 record, make a recursive call to fill it in as well. */
5694 static tree
5696 {
5701 {
5704 /* _Parent is an internal field, but may have values in the aggregate,
5705 so check for values first. */
5707 {
5710 }
5713 {
5718 }
5719 else
5720 /* If we have a record subtype, the names will match, but not the
5721 actual FIELD_DECLs. */
5724 {
5727 }
5733 }
5736 }
5737 \f
5738 /* EXP is to be treated as an array or record. Handle the cases when it is
5739 an access object and perform the required dereferences. */
5741 static tree
5743 {
5744 /* If the type is a pointer, dereference it. */
5749 /* If we got a padded type, remove it too. */
5755 }
5756 \f
5757 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
5759 tree
5761 {
5764 /* If this has no side effects, we don't need to do anything. */
5768 /* If it is a conversion, protect what's inside the conversion.
5769 Similarly, if we're indirectly referencing something, we only
5770 actually need to protect the address since the data itself can't
5771 change in these situations. */
5780 /* If EXP is a fat pointer or something that can be placed into a register,
5781 just make a SAVE_EXPR. */
5785 /* Otherwise, dereference, protect the address, and re-reference. */
5786 else
5787 return
5791 exp)));
5792 }
5793 \f
5794 /* This is equivalent to stabilize_reference in GCC's tree.c, but we know how
5795 to handle our new nodes and we take extra arguments:
5797 FORCE says whether to force evaluation of everything,
5799 SUCCESS we set to true unless we walk through something we don't know how
5800 to stabilize, or through something which is not an lvalue and LVALUES_ONLY
5801 is true, in which cases we set to false. */
5803 tree
5806 {
5809 tree result;
5811 /* Assume we'll success unless proven otherwise. */
5815 {
5819 /* No action is needed in this case. */
5823 /* A standalone ADDR_EXPR is never an lvalue, and this one can't
5824 be nested inside an outer INDIRECT_REF, since INDIREC_REF goes
5825 straight to stabilize_1. */
5829 /* ... Fallthru ... */
5839 result
5849 force));
5864 force),
5866 force));
5875 force),
5882 force),
5890 /* ... Fallthru to failure ... */
5892 /* If arg isn't a kind of lvalue we recognize, make no change.
5893 Caller should recognize the error for an invalid lvalue. */
5895 failure:
5898 }
5902 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS attached to the initial
5903 expression may not be sustained across some paths, such as the way via
5904 build1 for INDIRECT_REF. We re-populate those flags here for the general
5905 case, which is consistent with the GCC version of this routine.
5907 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
5908 paths introduce side effects where there was none initially (e.g. calls
5909 to save_expr), and we also want to keep track of that. */
5915 }
5917 /* Wrapper around maybe_stabilize_reference, for common uses without
5918 lvalue restrictions and without need to examine the success
5919 indication. */
5921 tree
5923 {
5926 }
5928 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
5929 arg to force a SAVE_EXPR for everything. */
5931 static tree
5933 {
5936 tree result;
5938 /* We cannot ignore const expressions because it might be a reference
5939 to a const array but whose index contains side-effects. But we can
5940 ignore things that are actual constant or that already have been
5941 handled by this function. */
5947 {
5955 /* If this is a COMPONENT_REF of a fat pointer, save the entire
5956 fat pointer. This may be more efficient, but will also allow
5957 us to more easily find the match for the PLACEHOLDER_EXPR. */
5962 force),
5966 else
5971 /* Constants need no processing. In fact, we should never reach
5972 here. */
5976 /* Recursively stabilize each operand. */
5980 force));
5984 /* Recursively stabilize each operand. */
5987 force));
5992 }
5999 }
6001 /* Build a global constructor or destructor function. METHOD_TYPE gives
6002 the type of the function and CDTORS points to the list of constructor
6003 or destructor functions to be invoked. FIXME: Migrate into cgraph. */
6005 static void
6007 {
6011 {
6016 NULL_TREE);
6018 }
6021 }
6022 \f
6025 /* Convert Sloc into *LOCUS (a location_t). Return true if this Sloc
6026 corresponds to a source code location and false if it doesn't. In the
6027 latter case, we don't update *LOCUS. We also set the Gigi global variable
6028 REF_FILENAME to the reference file name as given by sinput (i.e no
6029 directory). */
6031 bool
6033 {
6034 /* If node not from source code, ignore. */
6038 /* Use the identifier table to make a hashed, permanent copy of the filename,
6039 since the name table gets reallocated after Gigi returns but before all
6040 the debugging information is output. The __gnat_to_canonical_file_spec
6041 call translates filenames from pragmas Source_Reference that contain host
6042 style syntax not understood by gdb. */
6043 locus->file
6044 = IDENTIFIER_POINTER
6045 (get_identifier
6046 (__gnat_to_canonical_file_spec
6051 ref_filename
6052 = IDENTIFIER_POINTER
6053 (get_identifier
6057 }
6059 /* Similar to annotate_with_locus, but start with the Sloc of GNAT_NODE and
6060 don't do anything if it doesn't correspond to a source location. */
6062 static void
6064 {
6065 location_t locus;
6071 }
6072 \f
6073 /* Post an error message. MSG is the error message, properly annotated.
6074 NODE is the node at which to post the error and the node to use for the
6075 "&" substitution. */
6077 void
6079 {
6080 String_Template temp;
6081 Fat_Pointer fp;
6087 }
6089 /* Similar, but NODE is the node at which to post the error and ENT
6090 is the node to use for the "&" substitution. */
6092 void
6094 {
6095 String_Template temp;
6096 Fat_Pointer fp;
6102 }
6104 /* Similar, but NODE is the node at which to post the error, ENT is the node
6105 to use for the "&" substitution, and N is the number to use for the ^. */
6107 void
6109 {
6110 String_Template temp;
6111 Fat_Pointer fp;
6119 }
6120 \f
6121 /* Similar to post_error_ne_num, but T is a GCC tree representing the
6122 number to write. If the tree represents a constant that fits within
6123 a host integer, the text inside curly brackets in MSG will be output
6124 (presumably including a '^'). Otherwise that text will not be output
6125 and the text inside square brackets will be output instead. */
6127 void
6129 {
6132 Fat_Pointer fp;
6140 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
6141 &&
6142 compare_tree_int
6144 #endif
6145 )
6146 {
6149 }
6150 else
6154 {
6160 ;
6161 else
6163 }
6170 }
6172 /* Similar to post_error_ne_tree, except that NUM is a second
6173 integer to write in the message. */
6175 void
6177 Node_Id node,
6178 Entity_Id ent,
6179 tree t,
6181 {
6184 }
6185 \f
6186 /* Initialize the table that maps GNAT codes to GCC codes for simple
6187 binary and unary operations. */
6189 void
6191 {
6217 }