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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 {
1550 {
1554 }
1555 else
1557 }
1559 /* If we are calling by supplying a pointer to a target, set up that
1560 pointer as the first argument. Use GNU_TARGET if one was passed;
1561 otherwise, make a target by building a variable of the maximum size
1562 of the type. */
1564 {
1565 tree gnu_real_ret_type
1569 {
1570 tree gnu_obj_type
1576 /* ??? We may be about to create a static temporary if we happen to
1577 be at the global binding level. That's a regression from what
1578 the 3.x back-end would generate in the same situation, but we
1579 don't have a mechanism in Gigi for creating automatic variables
1580 in the elaboration routines. */
1581 gnu_target
1584 gnat_node);
1585 }
1587 gnu_actual_list
1591 gnu_target,
1593 NULL_TREE);
1595 }
1597 /* The only way we can be making a call via an access type is if Name is an
1598 explicit dereference. In that case, get the list of formal args from the
1599 type the access type is pointing to. Otherwise, get the formals from
1600 entity being called. */
1604 /* Assume here that this must be 'Elab_Body or 'Elab_Spec. */
1606 else
1609 /* Create the list of the actual parameters as GCC expects it, namely a chain
1610 of TREE_LIST nodes in which the TREE_VALUE field of each node is a
1611 parameter-expression and the TREE_PURPOSE field is null. Skip OUT
1612 parameters not passed by reference and don't need to be copied in. */
1617 {
1618 tree gnu_formal
1622 /* We treat a conversion between aggregate types as if it is an
1623 unchecked conversion. */
1624 bool unchecked_convert_p
1628 Node_Id gnat_name = (unchecked_convert_p
1632 tree gnu_actual;
1634 /* If it's possible we may need to use this expression twice, make sure
1635 than any side-effects are handled via SAVE_EXPRs. Likewise if we need
1636 to force side-effects before the call.
1638 ??? This is more conservative than we need since we don't need to do
1639 this for pass-by-ref with no conversion. If we are passing a
1640 non-addressable Out or In Out parameter by reference, pass the address
1641 of a copy and set up to copy back out after the call. */
1643 {
1647 && gnu_formal
1652 {
1654 tree gnu_temp;
1656 /* For users of Starlet we issue a warning because the
1657 interface apparently assumes that by-ref parameters
1658 outlive the procedure invocation. The code still
1659 will not work as intended, but we cannot do much
1660 better since other low-level parts of the back-end
1661 would allocate temporaries at will because of the
1662 misalignment if we did not do so here. */
1665 {
1666 post_error
1668 gnat_actual);
1669 post_error_ne
1672 post_error_ne
1675 }
1677 /* Remove any unpadding on the actual and make a copy. But if
1678 the actual is a justified modular type, first convert
1679 to it. */
1683 && (TYPE_IS_PADDING_P
1692 /* Since we're going to take the address of the SAVE_EXPR, we
1693 don't want it to be marked as unchanging. So set
1694 TREE_ADDRESSABLE. */
1697 {
1700 }
1702 /* Set up to move the copy back to the original. */
1708 /* Account for next statement just below. */
1710 }
1711 }
1713 /* If this was a procedure call, we may not have removed any padding.
1714 So do it here for the part we will use as an input, if any. */
1720 gnu_actual);
1722 /* Unless this is an In parameter, we must remove any LJM building
1723 from GNU_NAME. */
1729 gnu_name);
1732 && !unchecked_convert_p
1736 /* Do any needed conversions. We need only check for unchecked
1737 conversion since normal conversions will be handled by just
1738 converting to the formal type. */
1740 {
1741 gnu_actual
1743 gnu_actual,
1748 /* One we've done the unchecked conversion, we still must ensure that
1749 the object is in range of the formal's type. */
1754 }
1756 /* We may have suppressed a conversion to the Etype of the actual since
1757 the parent is a procedure call. So add the conversion here. */
1759 gnu_actual);
1764 /* If we have not saved a GCC object for the formal, it means it is an
1765 OUT parameter not passed by reference and that does not need to be
1766 copied in. Otherwise, look at the PARM_DECL to see if it is passed by
1767 reference. */
1770 {
1772 {
1775 /* If we have a padded type, be sure we've removed padding. */
1780 gnu_actual);
1782 /* If we have the constructed subtype of an aliased object
1783 with an unconstrained nominal subtype, the type of the
1784 actual includes the template, although it is formally
1785 constrained. So we need to convert it back to the real
1786 constructed subtype to retrieve the constrained part
1787 and takes its address. */
1794 gnu_actual);
1795 }
1797 /* Otherwise, if we have a non-addressable COMPONENT_REF of a
1798 variable-size type see if it's doing a unpadding operation. If
1799 so, remove that operation since we have no way of allocating the
1800 required temporary. */
1810 /* The symmetry of the paths to the type of an entity is broken here
1811 since arguments don't know that they will be passed by ref. */
1814 }
1817 {
1824 {
1827 }
1829 /* Take the address of the object and convert to the proper pointer
1830 type. We'd like to actually compute the address of the beginning
1831 of the array using an ADDR_EXPR of an ARRAY_REF, but there's a
1832 possibility that the ARRAY_REF might return a constant and we'd be
1833 getting the wrong address. Neither approach is exactly correct,
1834 but this is the most likely to work in all cases. */
1837 gnu_actual));
1838 }
1841 {
1842 /* If arg is 'Null_Parameter, pass zero descriptor. */
1847 integer_zero_node);
1848 else
1851 gnat_formal));
1852 }
1853 else
1854 {
1863 /* If this is 'Null_Parameter, pass a zero even though we are
1864 dereferencing it. */
1869 BITS_PER_WORD))
1870 gnu_actual
1875 integer_zero_node),
1877 else
1879 }
1882 }
1886 NULL_TREE);
1888 /* If we return by passing a target, we emit the call and return the target
1889 as our result. */
1891 {
1893 *gnu_result_type_p
1896 }
1898 /* If it is a function call, the result is the call expression unless
1899 a target is specified, in which case we copy the result into the target
1900 and return the assignment statement. */
1902 {
1905 /* If the function returns an unconstrained array or by reference,
1906 we have to de-dereference the pointer. */
1914 else
1918 }
1920 /* If this is the case where the GNAT tree contains a procedure call
1921 but the Ada procedure has copy in copy out parameters, the special
1922 parameter passing mechanism must be used. */
1924 {
1925 /* List of FIELD_DECLs associated with the PARM_DECLs of the copy
1926 in copy out parameters. */
1931 {
1932 tree gnu_name;
1937 /* If any of the names had side-effects, ensure they are all
1938 evaluated before the call. */
1944 }
1948 else
1955 /* If we are dealing with a copy in copy out parameter, we must
1956 retrieve its value from the record returned in the call. */
1962 || (DECL_BY_DESCRIPTOR_P
1965 {
1966 /* Get the value to assign to this OUT or IN OUT parameter. It is
1967 either the result of the function if there is only a single such
1968 parameter or the appropriate field from the record returned. */
1969 tree gnu_result
1976 /* If the actual is a conversion, get the inner expression, which
1977 will be the real destination, and convert the result to the
1978 type of the actual parameter. */
1979 tree gnu_actual
1982 /* If the result is a padded type, remove the padding. */
1987 gnu_result);
1989 /* If the result is a type conversion, do it. */
1991 gnu_result
1992 = convert_with_check
2000 gnu_result,
2002 else
2003 {
2011 }
2019 }
2020 }
2021 else
2022 {
2025 }
2029 }
2030 \f
2031 /* Subroutine of gnat_to_gnu to translate gnat_node, an
2032 N_Handled_Sequence_Of_Statements, to a GCC tree, which is returned. */
2034 static tree
2036 {
2039 /* If just annotating, ignore all EH and cleanups. */
2043 bool setjmp_longjmp
2049 tree gnu_result;
2050 tree gnu_expr;
2051 Node_Id gnat_temp;
2053 /* The GCC exception handling mechanism can handle both ZCX and SJLJ schemes
2054 and we have our own SJLJ mechanism. To call the GCC mechanism, we call
2055 add_cleanup, and when we leave the binding, end_stmt_group will create
2056 the TRY_FINALLY_EXPR.
2058 ??? The region level calls down there have been specifically put in place
2059 for a ZCX context and currently the order in which things are emitted
2060 (region/handlers) is different from the SJLJ case. Instead of putting
2061 other calls with different conditions at other places for the SJLJ case,
2062 it seems cleaner to reorder things for the SJLJ case and generalize the
2063 condition to make it not ZCX specific.
2065 If there are any exceptions or cleanup processing involved, we need an
2066 outer statement group (for Setjmp_Longjmp) and binding level. */
2068 {
2071 }
2073 /* If we are to call a function when exiting this block add a cleanup
2074 to the binding level we made above. */
2078 /* If using setjmp_longjmp, make the variables for the setjmp buffer and save
2079 area for address of previous buffer. Do this first since we need to have
2080 the setjmp buf known for any decls in this block. */
2082 {
2087 gnat_node);
2095 /* When we exit this block, restore the saved value. */
2097 }
2099 /* Now build the tree for the declarations and statements inside this block.
2100 If this is SJLJ, set our jmp_buf as the current buffer. */
2106 gnu_jmpbuf_decl)));
2112 /* Generate code for each statement in the block. */
2120 /* Now generate code for the two exception models, if either is relevant for
2121 this block. */
2123 {
2125 tree gnu_handler;
2127 /* Make a binding level for the exception handling declarations and code
2128 and set up gnu_except_ptr_stack for the handlers to use. */
2134 NULL_TREE,
2139 /* Generate code for each handler. The N_Exception_Handler case does the
2140 real work and returns a COND_EXPR for each handler, which we chain
2141 together here. */
2144 {
2147 /* If this is the first one, set it as the outer one. Otherwise,
2148 point the "else" part of the previous handler to us. Then point
2149 to our "else" part. */
2152 else
2156 }
2158 /* If none of the exception handlers did anything, re-raise but do not
2159 defer abortion. */
2166 else
2169 /* End the binding level dedicated to the exception handlers and get the
2170 whole statement group. */
2175 /* If the setjmp returns 1, we restore our incoming longjmp value and
2176 then check the handlers. */
2179 gnu_jmpsave_decl),
2180 gnat_node);
2184 /* This block is now "if (setjmp) ... <handlers> else <block>". */
2186 (build_call_1_expr
2189 gnu_jmpbuf_decl))),
2191 }
2193 {
2194 tree gnu_handlers;
2196 /* First make a block containing the handlers. */
2204 /* Now make the TRY_CATCH_EXPR for the block. */
2207 }
2208 else
2211 /* Now close our outer block, if we had to make one. */
2213 {
2217 }
2220 }
2221 \f
2222 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2223 to a GCC tree, which is returned. This is the variant for Setjmp_Longjmp
2224 exception handling. */
2226 static tree
2228 {
2229 /* Unless this is "Others" or the special "Non-Ada" exception for Ada, make
2230 an "if" statement to select the proper exceptions. For "Others", exclude
2231 exceptions where Handled_By_Others is nonzero unless the All_Others flag
2232 is set. For "Non-ada", accept an exception if "Lang" is 'V'. */
2235 Node_Id gnat_temp;
2239 {
2240 tree this_choice;
2243 {
2246 else
2247 this_choice
2248 = build_binary_op
2250 convert
2252 build_component_ref
2253 (build_unary_op
2258 integer_zero_node);
2259 }
2263 {
2265 tree gnu_expr;
2267 /* Exception may be a renaming. Recover original exception which is
2268 the one elaborated and registered. */
2274 this_choice
2275 = build_binary_op
2280 /* If this is the distinguished exception "Non_Ada_Error" (and we are
2281 in VMS mode), also allow a non-Ada exception (a VMS condition) t
2282 match. */
2284 {
2285 tree gnu_comp
2286 = build_component_ref
2291 this_choice
2292 = build_binary_op
2296 this_choice);
2297 }
2298 }
2299 else
2304 }
2307 }
2308 \f
2309 /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Exception_Handler,
2310 to a GCC tree, which is returned. This is the variant for ZCX. */
2312 static tree
2314 {
2316 tree gnu_expr;
2317 tree gnu_etype;
2318 tree gnu_current_exc_ptr;
2319 tree gnu_incoming_exc_ptr;
2320 Node_Id gnat_temp;
2322 /* We build a TREE_LIST of nodes representing what exception types this
2323 handler can catch, with special cases for others and all others cases.
2325 Each exception type is actually identified by a pointer to the exception
2326 id, or to a dummy object for "others" and "all others".
2328 Care should be taken to ensure that the control flow impact of "others"
2329 and "all others" is known to GCC. lang_eh_type_covers is doing the trick
2330 currently. */
2333 {
2335 {
2336 tree gnu_expr
2339 gnu_etype
2341 }
2344 {
2347 /* Exception may be a renaming. Recover original exception which is
2348 the one elaborated and registered. */
2355 /* The Non_Ada_Error case for VMS exceptions is handled
2356 by the personality routine. */
2357 }
2358 else
2361 /* The GCC interface expects NULL to be passed for catch all handlers, so
2362 it would be quite tempting to set gnu_etypes_list to NULL if gnu_etype
2363 is integer_zero_node. It would not work, however, because GCC's
2364 notion of "catch all" is stronger than our notion of "others". Until
2365 we correctly use the cleanup interface as well, doing that would
2366 prevent the "all others" handlers from being seen, because nothing
2367 can be caught beyond a catch all from GCC's point of view. */
2369 }
2374 /* Expand a call to the begin_handler hook at the beginning of the handler,
2375 and arrange for a call to the end_handler hook to occur on every possible
2376 exit path.
2378 The hooks expect a pointer to the low level occurrence. This is required
2379 for our stack management scheme because a raise inside the handler pushes
2380 a new occurrence on top of the stack, which means that this top does not
2381 necessarily match the occurrence this handler was dealing with.
2383 The EXC_PTR_EXPR object references the exception occurrence being
2384 propagated. Upon handler entry, this is the exception for which the
2385 handler is triggered. This might not be the case upon handler exit,
2386 however, as we might have a new occurrence propagated by the handler's
2387 body, and the end_handler hook called as a cleanup in this context.
2389 We use a local variable to retrieve the incoming value at handler entry
2390 time, and reuse it to feed the end_handler hook's argument at exit. */
2395 gnat_node);
2398 gnu_incoming_exc_ptr),
2399 gnat_node);
2406 }
2407 \f
2408 /* Subroutine of gnat_to_gnu to generate code for an N_Compilation unit. */
2410 static void
2412 {
2413 /* Make the decl for the elaboration procedure. */
2418 tree gnu_elab_proc_decl
2419 = create_subprog_decl
2423 gnat_unit_entity);
2433 /* For a body, first process the spec if there is one. */
2442 {
2449 }
2455 /* Process any pragmas and actions following the unit. */
2459 /* Save away what we've made so far and record this potential elaboration
2460 procedure. */
2470 /* Generate elaboration code for this unit, if necessary, and say whether
2471 we did or not. */
2474 /* Generate functions to call static constructors and destructors
2475 for targets that do not support .ctors/.dtors sections. These
2476 functions have magic names which are detected by collect2. */
2482 }
2483 \f
2484 /* This function is the driver of the GNAT to GCC tree transformation
2485 process. It is the entry point of the tree transformer. GNAT_NODE is the
2486 root of some GNAT tree. Return the root of the corresponding GCC tree.
2487 If this is an expression, return the GCC equivalent of the expression. If
2488 it is a statement, return the statement. In the case when called for a
2489 statement, it may also add statements to the current statement group, in
2490 which case anything it returns is to be interpreted as occurring after
2491 anything `it already added. */
2493 tree
2495 {
2499 tree gnu_expr;
2501 Node_Id gnat_temp;
2503 /* Save node number for error message and set location information. */
2511 /* If this node is a non-static subexpression and we are only
2512 annotating types, make this into a NULL_EXPR. */
2520 /* If this is a Statement and we are at top level, it must be part of the
2521 elaboration procedure, so mark us as being in that procedure and push our
2522 context.
2524 If we are in the elaboration procedure, check if we are violating a a
2525 No_Elaboration_Code restriction by having a statement there. */
2536 {
2538 {
2543 }
2545 /* Don't check for a possible No_Elaboration_Code restriction violation
2546 on N_Handled_Sequence_Of_Statements, as we want to signal an error on
2547 every nested real statement instead. This also avoids triggering
2548 spurious errors on dummy (empty) sequences created by the front-end
2549 for package bodies in some cases. */
2554 }
2557 {
2558 /********************************/
2559 /* Chapter 2: Lexical Elements: */
2560 /********************************/
2570 {
2571 tree gnu_type;
2573 /* Get the type of the result, looking inside any padding and
2574 justified modular types. Then get the value in that type. */
2583 /* If the result overflows (meaning it doesn't fit in its base type),
2584 abort. We would like to check that the value is within the range
2585 of the subtype, but that causes problems with subtypes whose usage
2586 will raise Constraint_Error and with biased representation, so
2587 we don't. */
2589 }
2593 /* If a Entity is present, it means that this was one of the
2594 literals in a user-defined character type. In that case,
2595 just return the value in the CONST_DECL. Otherwise, use the
2596 character code. In that case, the base type should be an
2597 INTEGER_TYPE, but we won't bother checking for that. */
2601 else
2602 gnu_result
2603 = force_fit_type
2604 (build_int_cst
2610 /* If this is of a fixed-point type, the value we want is the
2611 value of the corresponding integer. */
2613 {
2616 gnu_result_type);
2618 }
2620 /* We should never see a Vax_Float type literal, since the front end
2621 is supposed to transform these using appropriate conversions */
2625 else
2626 {
2631 /* If the real value is zero, so is the result. Otherwise,
2632 convert it to a machine number if it isn't already. That
2633 forces BASE to 0 or 2 and simplifies the rest of our logic. */
2636 else
2637 {
2639 ur_realval
2643 gnu_result
2646 /* If we have a base of zero, divide by the denominator.
2647 Otherwise, the base must be 2 and we scale the value, which
2648 we know can fit in the mantissa of the type (hence the use
2649 of that type above). */
2651 gnu_result
2654 gnu_result,
2656 gnu_result_type));
2657 else
2658 {
2659 REAL_VALUE_TYPE tmp;
2665 }
2666 }
2668 /* Now see if we need to negate the result. Do it this way to
2669 properly handle -0. */
2671 gnu_result
2673 gnu_result);
2674 }
2681 {
2687 /* Build the string with the characters in the literal. Note
2688 that Ada strings are 1-origin. */
2692 /* Put a null at the end of the string in case it's in a context
2693 where GCC will want to treat it as a C string. */
2698 /* Strings in GCC don't normally have types, but we want
2699 this to not be converted to the array type. */
2701 }
2702 else
2703 {
2704 /* Build a list consisting of each character, then make
2705 the aggregate. */
2713 {
2714 gnu_list
2719 gnu_list);
2723 }
2725 gnu_result
2727 }
2734 /**************************************/
2735 /* Chapter 3: Declarations and Types: */
2736 /**************************************/
2753 /* If we are just annotating types and this object has an unconstrained
2754 or task type, don't elaborate it. */
2765 && (!type_annotate_only
2767 {
2772 /* If this object has its elaboration delayed, we must force
2773 evaluation of GNU_EXPR right now and save it for when the object
2774 is frozen. */
2776 {
2779 gnu_expr
2784 else
2788 }
2789 }
2790 else
2803 /* Don't do anything if this renaming is handled by the front end or if
2804 we are just annotating types and this object has a composite or task
2805 type, don't elaborate it. We return the result in case it has any
2806 SAVE_EXPRs in it that need to be evaluated here. */
2808 && ! (type_annotate_only
2812 gnu_result
2815 else
2828 /* These are fully handled in the front end. */
2832 /*************************************/
2833 /* Chapter 4: Names and Expressions: */
2834 /*************************************/
2843 {
2845 tree gnu_type;
2853 /* If we got a padded type, remove it too. */
2856 gnu_array_object
2858 gnu_array_object);
2862 /* First compute the number of dimensions of the array, then
2863 fill the expression array, the order depending on whether
2864 this is a Convention_Fortran array or not. */
2869 ;
2878 else
2886 {
2892 gnu_expr
2893 = emit_index_check
2900 }
2901 }
2907 {
2908 tree gnu_type;
2914 /* Do any implicit dereferences of the prefix and do any needed
2915 range check. */
2920 {
2921 /* Get the bounds of the slice. */
2922 tree gnu_index_type
2928 /* Check to see that the minimum slice value is in range */
2929 gnu_expr_l
2930 = emit_index_check
2935 /* Check to see that the maximum slice value is in range */
2936 gnu_expr_h
2937 = emit_index_check
2942 /* Derive a good type to convert everything too */
2945 /* Build a compound expression that does the range checks */
2946 gnu_expr
2951 /* Build a conditional expression that returns the range checks
2952 expression if the slice range is not null (max >= min) or
2953 returns the min if the slice range is null */
2954 gnu_expr
2958 gnu_max_expr),
2960 gnu_min_expr)),
2962 }
2963 else
2968 }
2972 {
2976 tree gnu_field;
2980 {
2985 }
2989 /* For discriminant references in tagged types always substitute the
2990 corresponding discriminant as the actual selected component. */
2996 /* For discriminant references of untagged types always substitute the
2997 corresponding stored discriminant. */
3002 /* Handle extracting the real or imaginary part of a complex.
3003 The real part is the first field and the imaginary the last. */
3009 else
3010 {
3013 /* If there are discriminants, the prefix might be
3014 evaluated more than once, which is a problem if it has
3015 side-effects. */
3022 gnu_result
3026 }
3030 }
3034 {
3035 /* The attribute designator (like an enumeration value). */
3038 /* The Elab_Spec and Elab_Body attributes are special in that
3039 Prefix is a unit, not an object with a GCC equivalent. Similarly
3040 for Elaborated, since that variable isn't otherwise known. */
3044 attribute == Attr_Elab_Body
3047 gnat_node));
3050 }
3054 /* Like 'Access as far as we are concerned. */
3062 {
3063 tree gnu_aggr_type;
3065 /* ??? It is wrong to evaluate the type now, but there doesn't
3066 seem to be any other practical way of doing it. */
3070 gnu_aggr_type = gnu_result_type
3075 gnu_aggr_type
3083 {
3084 /* The first element is the discrimant, which we ignore. The
3085 next is the field we're building. Convert the expression
3086 to the type of the field and then to the union type. */
3087 Node_Id gnat_assoc
3090 tree gnu_field_type
3095 }
3098 gnu_result
3100 gnu_aggr_type);
3103 gnu_aggr_type,
3106 gnu_result
3107 = build_binary_op
3112 (Next
3114 else
3118 }
3128 /* Get the operand expression. */
3132 gnu_result
3144 /* If the result is a pointer type, see if we are improperly
3145 converting to a stricter alignment. */
3149 {
3155 post_error_ne_tree_2
3159 }
3167 {
3170 tree gnu_low;
3171 tree gnu_high;
3173 /* GNAT_RANGE is either an N_Range node or an identifier
3174 denoting a subtype. */
3176 {
3179 }
3182 {
3187 }
3188 else
3193 /* If LOW and HIGH are identical, perform an equality test.
3194 Otherwise, ensure that GNU_OBJECT is only evaluated once
3195 and perform a full range test. */
3199 else
3200 {
3202 gnu_result
3208 }
3212 }
3220 ? RDIV_EXPR
3227 /* These can either be operations on booleans or on modular types.
3228 Fall through for boolean types since that's the way GNU_CODES is
3229 set up. */
3231 Modular_Integer_Kind))
3232 {
3233 enum tree_code code
3244 }
3246 /* ... fall through ... */
3258 {
3260 tree gnu_type;
3266 /* If this is a comparison operator, convert any references to
3267 an unconstrained array value into a reference to the
3268 actual array. */
3270 {
3273 }
3275 /* If the result type is a private type, its full view may be a
3276 numeric subtype. The representation we need is that of its base
3277 type, given that it is the result of an arithmetic operation. */
3279 gnu_type = gnu_result_type
3282 /* If this is a shift whose count is not guaranteed to be correct,
3283 we need to adjust the shift count. */
3286 {
3288 tree gnu_max_shift
3296 gnu_rhs
3297 = build_binary_op
3300 gnu_count_type,
3301 gnu_max_shift,
3303 integer_one_node)),
3304 gnu_rhs);
3305 }
3307 /* For right shifts, the type says what kind of shift to do,
3308 so we may need to choose a different type. */
3317 {
3320 }
3324 /* If this is a logical shift with the shift count not verified,
3325 we must return zero if it is too large. We cannot compensate
3326 above in this case. */
3330 gnu_result
3331 = build_cond_expr
3334 gnu_rhs,
3338 gnu_result);
3339 }
3343 {
3346 tree gnu_false
3353 }
3362 /* This case can apply to a boolean or a modular type.
3363 Fall through for a boolean operand since GNU_CODES is set
3364 up to handle this. */
3366 {
3370 gnu_expr);
3372 }
3374 /* ... fall through ... */
3381 else
3390 {
3392 tree gnu_type;
3397 /* The Expression operand can either be an N_Identifier or
3398 Expanded_Name, which must represent a type, or a
3399 N_Qualified_Expression, which contains both the object type and an
3400 initial value for the object. */
3405 {
3406 Entity_Id gnat_desig_type
3418 {
3421 }
3422 else
3423 {
3429 }
3430 }
3431 else
3438 ignore_init_type);
3439 }
3442 /***************************/
3443 /* Chapter 5: Statements: */
3444 /***************************/
3456 /* Get the LHS and RHS of the statement and convert any reference to an
3457 unconstrained array into a reference to the underlying array.
3458 If we are not to do range checking and the RHS is an N_Function_Call,
3459 pass the LHS to the call function. */
3462 /* If the type has a size that overflows, convert this into raise of
3463 Storage_Error: execution shouldn't have gotten here anyway. */
3471 else
3472 {
3473 gnu_rhs
3476 /* If range check is needed, emit code to generate it */
3480 gnu_result
3482 }
3486 {
3489 /* Make the outer COND_EXPR. Avoid non-determinism. */
3498 /* Now make a COND_EXPR for each of the "else if" parts. Put each
3499 into the previous "else" part and point to where to put any
3500 outer "else". Also avoid non-determinism. */
3504 {
3514 }
3517 }
3541 gnu_result
3551 {
3552 /* The gnu function type of the subprogram currently processed. */
3554 /* The return value from the subprogram. */
3556 /* The place to put the return value. */
3557 tree gnu_lhs;
3559 /* If we are dealing with a "return;" from an Ada procedure with
3560 parameters passed by copy in copy out, we need to return a record
3561 containing the final values of these parameters. If the list
3562 contains only one entry, return just that entry.
3564 For a full description of the copy in copy out parameter mechanism,
3565 see the part of the gnat_to_gnu_entity routine dealing with the
3566 translation of subprograms.
3568 But if we have a return label defined, convert this into
3569 a branch to that label. */
3572 {
3576 }
3579 {
3583 else
3584 gnu_ret_val
3587 }
3589 /* If the Ada subprogram is a function, we just need to return the
3590 expression. If the subprogram returns an unconstrained
3591 array, we have to allocate a new version of the result and
3592 return it. If we return by reference, return a pointer. */
3595 {
3596 /* If the current function returns by target pointer and we
3597 are doing a call, pass that target to the call. */
3600 {
3601 gnu_lhs
3606 }
3607 else
3608 {
3612 /* The original return type was unconstrained so dereference
3613 the TARGET pointer in the actual return value's type. */
3614 gnu_lhs
3617 else
3620 /* Do not remove the padding from GNU_RET_VAL if the inner
3621 type is self-referential since we want to allocate the fixed
3622 size in that case. */
3626 && (TYPE_IS_PADDING_P
3628 && (CONTAINS_PLACEHOLDER_P
3634 gnu_ret_val
3638 {
3641 /* We have two cases: either the function returns with
3642 depressed stack or not. If not, we allocate on the
3643 secondary stack. If so, we allocate in the stack frame.
3644 if no copy is needed, the front end will set By_Ref,
3645 which we handle in the case above. */
3647 gnu_ret_val
3649 gnu_ret_val,
3652 else
3653 gnu_ret_val
3655 gnu_ret_val,
3660 }
3661 }
3662 }
3663 else
3664 /* If the Ada subprogram is a regular procedure, just return. */
3668 {
3674 }
3677 }
3685 /****************************/
3686 /* Chapter 6: Subprograms: */
3687 /****************************/
3690 /* Unless there is a freeze node, declare the subprogram. We consider
3691 this a "definition" even though we're not generating code for
3692 the subprogram because we will be making the corresponding GCC
3693 node here. */
3702 /* This subprogram doesn't exist for code generation purposes, but we
3703 have to elaborate the types of any parameters, unless they are
3704 imported types (nothing to generate in this case). */
3717 /* For a child unit identifier go up a level to get the
3718 specification. We get this when we try to find the spec of
3719 a child unit package that is the compilation unit being compiled. */
3733 /*************************/
3734 /* Chapter 7: Packages: */
3735 /*************************/
3751 /* If this is the body of a generic package - do nothing */
3753 {
3756 }
3767 /*********************************/
3768 /* Chapter 8: Visibility Rules: */
3769 /*********************************/
3773 /* Nothing to do here - but these may appear in list of declarations */
3777 /***********************/
3778 /* Chapter 9: Tasks: */
3779 /***********************/
3790 /***********************************************************/
3791 /* Chapter 10: Program Structure and Compilation Issues: */
3792 /***********************************************************/
3796 /* This is not called for the main unit, which is handled in function
3797 gigi above. */
3809 /* Simply process whatever unit is being inserted. */
3817 /***************************/
3818 /* Chapter 11: Exceptions: */
3819 /***************************/
3822 /* If there is an At_End procedure attached to this node, and the EH
3823 mechanism is SJLJ, we must have at least a corresponding At_End
3824 handler, unless the No_Exception_Handlers restriction is set. */
3839 else
3844 /*******************************/
3845 /* Chapter 12: Generic Units: */
3846 /*******************************/
3856 /* These nodes can appear on a declaration list but there is nothing to
3857 to be done with them. */
3861 /***************************************************/
3862 /* Chapter 13: Representation Clauses and */
3863 /* Implementation-Dependent Features: */
3864 /***************************************************/
3870 /* The only one we need deal with is for 'Address. For the others, SEM
3871 puts the information elsewhere. We need only deal with 'Address
3872 if the object has a Freeze_Node (which it never will currently). */
3877 /* Get the value to use as the address and save it as the
3878 equivalent for GNAT_TEMP. When the object is frozen,
3879 gnat_to_gnu_entity will do the right thing. */
3887 /* We do nothing with these. SEM puts the information elsewhere. */
3893 {
3899 /* First process inputs, then outputs, then clobbers. */
3902 {
3907 gnu_input_list
3910 }
3914 {
3919 gnu_output_list
3922 }
3926 gnu_clobber_list
3929 gnu_clobber_list);
3937 }
3938 else
3943 /***************************************************/
3944 /* Added Nodes */
3945 /***************************************************/
3963 {
3966 tree gnu_obj_type;
3968 tree gnu_obj_size;
3971 /* If this is a thin pointer, we must dereference it to create
3972 a fat pointer, then go back below to a thin pointer. The
3973 reason for this is that we need a fat pointer someplace in
3974 order to properly compute the size. */
3978 gnu_ptr));
3980 /* If this is an unconstrained array, we know the object must
3981 have been allocated with the template in front of the object.
3982 So pass the template address, but get the total size. Do this
3983 by converting to a thin pointer. */
3985 gnu_ptr
3987 (TYPE_OBJECT_RECORD_TYPE
3989 gnu_ptr);
3994 {
3998 gnu_actual_obj_type
4000 gnu_actual_obj_type,
4002 }
4003 else
4011 {
4014 tree gnu_byte_offset
4021 }
4026 gnat_node);
4027 }
4034 {
4037 }
4042 /* If the type is VOID, this is a statement, so we need to
4043 generate the code for the call. Handle a Condition, if there
4044 is one. */
4046 {
4053 }
4054 else
4059 /* If the result is a pointer type, see if we are either converting
4060 from a non-pointer or from a pointer to a type with a different
4061 alias set and warn if so. If the result defined in the same unit as
4062 this unchecked conversion, we can allow this because we can know to
4063 make that type have alias set 0. */
4064 {
4075 {
4076 post_error_ne
4079 post_error
4081 gnat_node);
4082 post_error_ne
4085 }
4087 /* The No_Strict_Aliasing flag is not propagated to the back-end for
4088 fat pointers so unconditionally warn in problematic cases. */
4090 {
4091 tree array_type
4098 {
4099 post_error_ne
4102 post_error
4104 gnat_node);
4105 }
4106 }
4107 }
4120 }
4122 /* If we pushed our level as part of processing the elaboration routine,
4123 pop it back now. */
4125 {
4130 }
4132 /* Set the location information into the result. Note that we may have
4133 no result if we tried to build a CALL_EXPR node to a procedure with
4134 no side-effects and optimization is enabled. */
4138 /* If we're supposed to return something of void_type, it means we have
4139 something we're elaborating for effect, so just return. */
4143 /* If the result is a constant that overflows, raise constraint error. */
4146 {
4149 gnu_result
4152 }
4154 /* If our result has side-effects and is of an unconstrained type,
4155 make a SAVE_EXPR so that we can be sure it will only be referenced
4156 once. Note we must do this before any conversions. */
4162 /* Now convert the result to the proper type. If the type is void or if
4163 we have no result, return error_mark_node to show we have no result.
4164 If the type of the result is correct or if we have a label (which doesn't
4165 have any well-defined type), return our result. Also don't do the
4166 conversion if the "desired" type involves a PLACEHOLDER_EXPR in its size
4167 since those are the cases where the front end may have the type wrong due
4168 to "instantiating" the unconstrained record with discriminant values
4169 or if this is a FIELD_DECL. If this is the Name of an assignment
4170 statement or a parameter of a procedure call, return what we have since
4171 the RHS has to be converted to our type there in that case, unless
4172 GNU_RESULT_TYPE has a simpler size. Similarly, if the two types are
4173 record types with the same name, the expression type has integral mode,
4174 and GNU_RESULT_TYPE BLKmode, don't convert. This will be the case when
4175 we are converting from a packable type to its actual type and we need
4176 those conversions to be NOPs in order for assignments into these types to
4177 work properly if the inner object is a bitfield and hence can't have
4178 its address taken. Finally, don't convert integral types that are the
4179 operand of an unchecked conversion since we need to ignore those
4180 conversions (for 'Valid). Otherwise, convert the result to the proper
4181 type. */
4201 && (CONTAINS_PLACEHOLDER_P
4205 {
4206 /* In this case remove padding only if the inner object is of
4207 self-referential size: in that case it must be an object of
4208 unconstrained type with a default discriminant. In other cases,
4209 we want to avoid copying too much data. */
4216 gnu_result);
4217 }
4233 {
4234 /* Remove any padding record, but do nothing more in this case. */
4238 gnu_result);
4239 }
4247 /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RESULT. */
4254 }
4255 \f
4256 /* Record the current code position in GNAT_NODE. */
4258 static void
4260 {
4265 }
4267 /* Insert the code for GNAT_NODE at the position saved for that node. */
4269 static void
4271 {
4274 }
4275 \f
4276 /* Start a new statement group chained to the previous group. */
4278 static void
4280 {
4283 /* First see if we can get one from the free list. */
4286 else
4292 }
4294 /* Add GNU_STMT to the current statement group. */
4296 void
4298 {
4301 /* If we're at top level, show everything in here is in use in case
4302 any of it is shared by a subprogram. */
4306 }
4308 /* Similar, but set the location of GNU_STMT to that of GNAT_NODE. */
4310 void
4312 {
4316 }
4318 /* Add a declaration statement for GNU_DECL to the current statement group.
4319 Get SLOC from Entity_Id. */
4321 void
4323 {
4324 tree gnu_stmt;
4326 /* If this is a variable that Gigi is to ignore, we may have been given
4327 an ERROR_MARK. So test for it. We also might have been given a
4328 reference for a renaming. So only do something for a decl. Also
4329 ignore a TYPE_DECL for an UNCONSTRAINED_ARRAY_TYPE. */
4335 /* If we are global, we don't want to actually output the DECL_EXPR for
4336 this decl since we already have evaluated the expressions in the
4337 sizes and positions as globals and doing it again would be wrong.
4338 But we do have to mark everything as used. */
4342 else
4343 {
4347 {
4351 }
4352 }
4354 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set,
4355 there are two cases we need to handle here. */
4357 {
4361 /* If this is a DECL_EXPR for a variable with DECL_INITIAL set
4362 and decl has a padded type, convert it to the unpadded type so the
4363 assignment is done properly. */
4366 gnu_lhs
4369 /* Otherwise, if this is going into memory and the initializer isn't
4370 valid for the assembler and loader. Gimplification could do this,
4371 but would be run too late if -fno-unit-at-a-time. */
4378 {
4379 tree gnu_assign_stmt
4388 }
4389 }
4390 }
4392 /* Utility function to mark nodes with TREE_VISITED and types as having their
4393 sized gimplified. Called from walk_tree. We use this to indicate all
4394 variable sizes and positions in global types may not be shared by any
4395 subprogram. */
4397 static tree
4399 {
4403 /* Don't mark a dummy type as visited because we want to mark its sizes
4404 and fields once it's filled in. */
4412 }
4414 /* Likewise, but to mark as unvisited. */
4416 static tree
4419 {
4423 }
4425 /* Add GNU_CLEANUP, a cleanup action, to the current code group. */
4427 static void
4429 {
4431 }
4433 /* Set the BLOCK node corresponding to the current code group to GNU_BLOCK. */
4435 void
4437 {
4440 }
4442 /* Return code corresponding to the current code group. It is normally
4443 a STATEMENT_LIST, but may also be a BIND_EXPR or TRY_FINALLY_EXPR if
4444 BLOCK or cleanups were set. */
4446 static tree
4448 {
4452 /* If this is a null list, allocate a new STATEMENT_LIST. Then, if there
4453 are cleanups, make a TRY_FINALLY_EXPR. Last, if there is a BLOCK,
4454 make a BIND_EXPR. Note that we nest in that because the cleanup may
4455 reference variables in the block. */
4467 /* Remove this group from the stack and add it to the free list. */
4473 }
4475 /* Add a list of statements from GNAT_LIST, a possibly-empty list of
4476 statements.*/
4478 static void
4480 {
4481 Node_Id gnat_node;
4487 }
4489 /* Build a tree from GNAT_LIST, a possibly-empty list of statements.
4490 If BINDING_P is true, push and pop a binding level around the list. */
4492 static tree
4494 {
4504 }
4505 \f
4506 /* Push and pop routines for stacks. We keep a free list around so we
4507 don't waste tree nodes. */
4509 static void
4511 {
4515 {
4520 }
4521 else
4525 }
4527 static void
4529 {
4535 }
4536 \f
4537 /* GNU_STMT is a statement. We generate code for that statement. */
4539 void
4541 {
4542 #if 0
4544 #endif
4547 {
4548 #if 0
4550 /* First write a volatile ASM_INPUT to prevent anything from being
4551 moved. */
4557 modifier);
4560 #endif
4564 }
4565 }
4566 \f
4567 /* Generate GIMPLE in place for the expression at *EXPR_P. */
4569 int
4571 {
4573 tree op;
4579 {
4581 /* If this is for a scalar, just make a VAR_DECL for it. If for
4582 an aggregate, get a null pointer of the appropriate type and
4583 dereference it. */
4587 integer_zero_node));
4588 else
4589 {
4592 }
4598 /* We should only do this if we are just elaborating for side-effects,
4599 but we can't know that yet. */
4606 /* If we're taking the address of a constant CONSTRUCTOR, force it to
4607 be put into static memory. We know it's going to be readonly given
4608 the semantics we have and it's required to be static memory in
4609 the case when the reference is in an elaboration procedure. */
4611 {
4622 }
4624 /* Otherwise, if we are taking the address of something that is neither
4625 reference, declaration, or constant, make a variable for the operand
4626 here and then take its address. If we don't do it this way, we may
4627 confuse the gimplifier because it needs to know the variable is
4628 addressable at this point. This duplicates code in
4629 internal_get_tmp_var, which is unfortunate. */
4633 {
4646 }
4651 /* We have a kludge here. If the FIELD_DECL is from a fat pointer and is
4652 from an early dummy type, replace it with the proper FIELD_DECL. */
4655 {
4659 }
4661 /* ... fall through ... */
4665 }
4666 }
4668 /* Generate GIMPLE in place for the statement at *STMT_P. */
4670 static enum gimplify_status
4672 {
4676 {
4686 {
4690 /* Set to emit the statements of the loop. */
4693 /* We first emit the start label and then a conditional jump to
4694 the end label if there's a top condition, then the body of the
4695 loop, then a conditional branch to the end label, then the update,
4696 if any, and finally a jump to the start label and the definition
4697 of the end label. */
4699 gnu_start_label),
4700 stmt_p);
4707 void_type_node,
4708 gnu_end_label)),
4709 stmt_p);
4718 void_type_node,
4719 gnu_end_label)),
4720 stmt_p);
4726 gnu_start_label),
4727 stmt_p);
4729 gnu_end_label),
4730 stmt_p);
4732 }
4735 /* Build a statement to jump to the corresponding end label, then
4736 see if it needs to be conditional. */
4745 }
4746 }
4747 \f
4748 /* Force references to each of the entities in packages GNAT_NODE with's
4749 so that the debugging information for all of them are identical
4750 in all clients. Operate recursively on anything it with's, but check
4751 that we aren't elaborating something more than once. */
4753 /* The reason for this routine's existence is two-fold.
4754 First, with some debugging formats, notably MDEBUG on SGI
4755 IRIX, the linker will remove duplicate debugging information if two
4756 clients have identical debugguing information. With the normal scheme
4757 of elaboration, this does not usually occur, since entities in with'ed
4758 packages are elaborated on demand, and if clients have different usage
4759 patterns, the normal case, then the order and selection of entities
4760 will differ. In most cases however, it seems that linkers do not know
4761 how to eliminate duplicate debugging information, even if it is
4762 identical, so the use of this routine would increase the total amount
4763 of debugging information in the final executable.
4765 Second, this routine is called in type_annotate mode, to compute DDA
4766 information for types in withed units, for ASIS use */
4768 static void
4770 {
4773 /* Process each unit only once. As we trace the context of all relevant
4774 units transitively, including generic bodies, we may encounter the
4775 same generic unit repeatedly */
4780 /* Save entities in all context units. A body may have an implicit_with
4781 on its own spec, if the context includes a child unit, so don't save
4782 the spec twice. */
4790 {
4794 {
4811 }
4813 {
4814 Node_Id gnat_body
4817 /* Retrieve compilation unit node of generic body. */
4822 /* If body is available, elaborate its context. */
4825 }
4826 }
4830 }
4831 \f
4832 /* Do the processing of N_Freeze_Entity, GNAT_NODE. */
4834 static void
4836 {
4838 tree gnu_old;
4839 tree gnu_new;
4840 tree gnu_init
4845 /* If this is a package, need to generate code for the package. */
4847 {
4848 insert_code_for
4852 }
4854 /* Check for old definition after the above call. This Freeze_Node
4855 might be for one its Itypes. */
4856 gnu_old
4859 /* If this entity has an Address representation clause, GNU_OLD is the
4860 address, so discard it here. */
4864 /* Don't do anything for class-wide types they are always
4865 transformed into their root type. */
4871 /* Don't do anything for subprograms that may have been elaborated before
4872 their freeze nodes. This can happen, for example because of an inner call
4873 in an instance body, or a previous compilation of a spec for inlining
4874 purposes. */
4879 || (gnu_old
4884 /* If we have a non-dummy type old tree, we have nothing to do. Unless
4885 this is the public view of a private type whose full view was not
4886 delayed, this node was never delayed as it should have been.
4887 Also allow this to happen for concurrent types since we may have
4888 frozen both the Corresponding_Record_Type and this type. */
4892 {
4898 }
4900 /* Reset the saved tree, if any, and elaborate the object or type for real.
4901 If there is a full declaration, elaborate it and copy the type to
4902 GNAT_ENTITY. Likewise if this is the record subtype corresponding to
4903 a class wide type or subtype. */
4905 {
4914 }
4918 {
4921 /* Propagate back-annotations from full view to partial view. */
4931 /* The above call may have defined this entity (the simplest example
4932 of this is when we have a private enumeral type since the bounds
4933 will have the public view. */
4939 }
4940 else
4943 /* If we've made any pointers to the old version of this type, we
4944 have to update them. */
4948 }
4949 \f
4950 /* Process the list of inlined subprograms of GNAT_NODE, which is an
4951 N_Compilation_Unit. */
4953 static void
4955 {
4956 Entity_Id gnat_entity;
4957 Node_Id gnat_body;
4959 /* If we can inline, generate RTL for all the inlined subprograms.
4960 Define the entity first so we set DECL_EXTERNAL. */
4965 {
4969 {
4970 /* ??? This really should always be Present. */
4974 gnat_body
4976 }
4979 {
4982 }
4983 }
4984 }
4985 \f
4986 /* Elaborate decls in the lists GNAT_DECLS and GNAT_DECLS2, if present.
4987 We make two passes, one to elaborate anything other than bodies (but
4988 we declare a function if there was no spec). The second pass
4989 elaborates the bodies.
4991 GNAT_END_LIST gives the element in the list past the end. Normally,
4992 this is Empty, but can be First_Real_Statement for a
4993 Handled_Sequence_Of_Statements.
4995 We make a complete pass through both lists if PASS1P is true, then make
4996 the second pass over both lists if PASS2P is true. The lists usually
4997 correspond to the public and private parts of a package. */
4999 static void
5002 {
5004 Node_Id gnat_decl;
5014 {
5015 /* For package specs, we recurse inside the declarations,
5016 thus taking the two pass approach inside the boundary. */
5024 /* Similarly for any declarations in the actions of a
5025 freeze node. */
5027 {
5030 }
5032 /* Package bodies with freeze nodes get their elaboration deferred
5033 until the freeze node, but the code must be placed in the right
5034 place, so record the code position now. */
5042 (Corresponding_Spec
5045 record_code_position
5048 /* We defer most subprogram bodies to the second pass. */
5050 {
5052 {
5058 }
5059 }
5060 /* For bodies and stubs that act as their own specs, the entity
5061 itself must be elaborated in the first pass, because it may
5062 be used in other declarations. */
5064 {
5065 Node_Id gnat_subprog_id =
5072 }
5074 /* Concurrent stubs stand for the corresponding subprogram bodies,
5075 which are deferred like other bodies. */
5078 ;
5079 else
5081 }
5083 /* Here we elaborate everything we deferred above except for package bodies,
5084 which are elaborated at their freeze nodes. Note that we must also
5085 go inside things (package specs and freeze nodes) the first pass did. */
5091 {
5107 }
5108 }
5109 \f
5110 /* Emit code for a range check. GNU_EXPR is the expression to be checked,
5111 GNAT_RANGE_TYPE the gnat type or subtype containing the bounds against
5112 which we have to check. */
5114 static tree
5116 {
5122 /* If GNU_EXPR has an integral type that is narrower than GNU_RANGE_TYPE,
5123 we can't do anything since we might be truncating the bounds. No
5124 check is needed in this case. */
5130 /* Checked expressions must be evaluated only once. */
5133 /* There's no good type to use here, so we might as well use
5134 integer_type_node. Note that the form of the check is
5135 (not (expr >= lo)) or (not (expr >= hi))
5136 the reason for this slightly convoluted form is that NaN's
5137 are not considered to be in range in the float case. */
5138 return emit_check
5140 invert_truthvalue
5144 invert_truthvalue
5148 gnu_high)))),
5150 }
5151 \f
5152 /* Emit code for an index check. GNU_ARRAY_OBJECT is the array object
5153 which we are about to index, GNU_EXPR is the index expression to be
5154 checked, GNU_LOW and GNU_HIGH are the lower and upper bounds
5155 against which GNU_EXPR has to be checked. Note that for index
5156 checking we cannot use the emit_range_check function (although very
5157 similar code needs to be generated in both cases) since for index
5158 checking the array type against which we are checking the indeces
5159 may be unconstrained and consequently we need to retrieve the
5160 actual index bounds from the array object itself
5161 (GNU_ARRAY_OBJECT). The place where we need to do that is in
5162 subprograms having unconstrained array formal parameters */
5164 static tree
5166 tree gnu_expr,
5167 tree gnu_low,
5168 tree gnu_high)
5169 {
5170 tree gnu_expr_check;
5172 /* Checked expressions must be evaluated only once. */
5175 /* Must do this computation in the base type in case the expression's
5176 type is an unsigned subtypes. */
5179 /* If GNU_LOW or GNU_HIGH are a PLACEHOLDER_EXPR, qualify them by
5180 the object we are handling. */
5184 /* There's no good type to use here, so we might as well use
5185 integer_type_node. */
5186 return emit_check
5189 gnu_expr_check,
5191 gnu_low)),
5193 gnu_expr_check,
5195 gnu_high))),
5197 }
5198 \f
5199 /* GNU_COND contains the condition corresponding to an access, discriminant or
5200 range check of value GNU_EXPR. Build a COND_EXPR that returns GNU_EXPR if
5201 GNU_COND is false and raises a CONSTRAINT_ERROR if GNU_COND is true.
5202 REASON is the code that says why the exception was raised. */
5204 static tree
5206 {
5207 tree gnu_call;
5208 tree gnu_result;
5212 /* Use an outer COMPOUND_EXPR to make sure that GNU_EXPR will get evaluated
5213 in front of the comparison in case it ends up being a SAVE_EXPR. Put the
5214 whole thing inside its own SAVE_EXPR so the inner SAVE_EXPR doesn't leak
5215 out. */
5219 gnu_expr));
5221 /* If GNU_EXPR has side effects, make the outer COMPOUND_EXPR and
5222 protect it. Otherwise, show GNU_RESULT has no side effects: we
5223 don't need to evaluate it just for the check. */
5225 gnu_result
5227 else
5230 /* ??? Unfortunately, if we don't put a SAVE_EXPR around this whole thing,
5231 we will repeatedly do the test. It would be nice if GCC was able
5232 to optimize this and only do it once. */
5234 }
5235 \f
5236 /* Return an expression that converts GNU_EXPR to GNAT_TYPE, doing
5237 overflow checks if OVERFLOW_P is nonzero and range checks if
5238 RANGE_P is nonzero. GNAT_TYPE is known to be an integral type.
5239 If TRUNCATE_P is nonzero, do a float to integer conversion with
5240 truncation; otherwise round. */
5242 static tree
5245 {
5253 /* If we are not doing any checks, the output is an integral type, and
5254 the input is not a floating type, just do the conversion. This
5255 shortcut is required to avoid problems with packed array types
5256 and simplifies code in all cases anyway. */
5261 /* First convert the expression to its base type. This
5262 will never generate code, but makes the tests below much simpler.
5263 But don't do this if converting from an integer type to an unconstrained
5264 array type since then we need to get the bounds from the original
5265 (unpacked) type. */
5269 /* If overflow checks are requested, we need to be sure the result will
5270 fit in the output base type. But don't do this if the input
5271 is integer and the output floating-point. */
5274 {
5275 /* Ensure GNU_EXPR only gets evaluated once. */
5283 /* Convert the lower bounds to signed types, so we're sure we're
5284 comparing them properly. Likewise, convert the upper bounds
5285 to unsigned types. */
5299 /* Check each bound separately and only if the result bound
5300 is tighter than the bound on the input type. Note that all the
5301 types are base types, so the bounds must be constant. Also,
5302 the comparison is done in the base type of the input, which
5303 always has the proper signedness. First check for input
5304 integer (which means output integer), output float (which means
5305 both float), or mixed, in which case we always compare.
5306 Note that we have to do the comparison which would *fail* in the
5307 case of an error since if it's an FP comparison and one of the
5308 values is a NaN or Inf, the comparison will fail. */
5315 gnu_cond
5316 = invert_truthvalue
5319 gnu_out_lb)));
5327 gnu_cond
5329 invert_truthvalue
5331 gnu_input,
5333 gnu_out_ub))));
5337 CE_Overflow_Check_Failed);
5338 }
5340 /* Now convert to the result base type. If this is a non-truncating
5341 float-to-integer conversion, round. */
5344 {
5350 /* The following calculations depend on proper rounding to even
5351 of each arithmetic operation. In order to prevent excess
5352 precision from spoiling this property, use the widest hardware
5353 floating-point type.
5355 FIXME: For maximum efficiency, this should only be done for machines
5356 and types where intermediates may have extra precision. */
5359 /* FIXME: Should not have padding in the first place */
5364 /* Compute the exact value calc_type'Pred (0.5) at compile time. */
5368 half_minus_pred_half);
5371 /* If the input is strictly negative, subtract this value
5372 and otherwise add it from the input. For 0.5, the result
5373 is exactly between 1.0 and the machine number preceding 1.0
5374 (for calc_type). Since the last bit of 1.0 is even, this 0.5
5375 will round to 1.0, while all other number with an absolute
5376 value less than 0.5 round to 0.0. For larger numbers exactly
5377 halfway between integers, rounding will always be correct as
5378 the true mathematical result will be closer to the higher
5379 integer compared to the lower one. So, this constant works
5380 for all floating-point numbers.
5382 The reason to use the same constant with subtract/add instead
5383 of a positive and negative constant is to allow the comparison
5384 to be scheduled in parallel with retrieval of the constant and
5385 conversion of the input to the calc_type (if necessary).
5386 */
5393 gnu_add_pred_half
5395 gnu_subtract_pred_half
5399 }
5405 else
5408 /* Finally, do the range check if requested. Note that if the
5409 result type is a modular type, the range check is actually
5410 an overflow check. */
5418 }
5419 \f
5420 /* Return 1 if GNU_EXPR can be directly addressed. This is the case unless
5421 it is an expression involving computation or if it involves a reference
5422 to a bitfield or to a field not sufficiently aligned for its type. */
5424 static bool
5426 {
5428 {
5433 /* All DECLs are addressable: if they are in a register, we can force
5434 them to memory. */
5446 && (!STRICT_ALIGNMENT
5447 /* If the field was marked as "semantically" addressable
5448 in create_field_decl, we are guaranteed that it can
5449 be directly addressed. */
5451 /* Otherwise it can nevertheless be directly addressed
5452 if it has been sufficiently aligned in the record. */
5467 {
5468 /* This is addressable if we can avoid a copy. */
5482 }
5486 }
5487 }
5488 \f
5489 /* Do the processing for the declaration of a GNAT_ENTITY, a type. If
5490 a separate Freeze node exists, delay the bulk of the processing. Otherwise
5491 make a GCC type for GNAT_ENTITY and set up the correspondence. */
5493 void
5495 {
5496 tree gnu_old
5498 tree gnu_new;
5500 /* If we are to delay elaboration of this type, just do any
5501 elaborations needed for expressions within the declaration and
5502 make a dummy type entry for this node and its Full_View (if
5503 any) in case something points to it. Don't do this if it
5504 has already been done (the only way that can happen is if
5505 the private completion is also delayed). */
5511 {
5515 {
5524 }
5527 }
5529 /* If we saved away a dummy type for this node it means that this
5530 made the type that corresponds to the full type of an incomplete
5531 type. Clear that type for now and then update the type in the
5532 pointers. */
5534 {
5537 {
5538 /* If this was a withed access type, this is not an error
5539 and merely indicates we've already elaborated the type
5540 already. */
5543 }
5546 }
5548 /* Now fully elaborate the type. */
5552 /* If we have an old type and we've made pointers to this type,
5553 update those pointers. */
5558 /* If this is a record type corresponding to a task or protected type
5559 that is a completion of an incomplete type, perform a similar update
5560 on the type. */
5561 /* ??? Including protected types here is a guess. */
5566 {
5567 tree gnu_task_old
5577 }
5578 }
5579 \f
5580 /* GNAT_ASSOC is the front of the Component_Associations of an N_Aggregate.
5581 GNU_TYPE is the GCC type of the corresponding record.
5583 Return a CONSTRUCTOR to build the record. */
5585 static tree
5587 {
5590 /* We test for GNU_FIELD being empty in the case where a variant
5591 was the last thing since we don't take things off GNAT_ASSOC in
5592 that case. We check GNAT_ASSOC in case we have a variant, but it
5593 has no fields. */
5597 {
5602 /* The expander is supposed to put a single component selector name
5603 in every record component association */
5606 /* Ignore fields that have Corresponding_Discriminants since we'll
5607 be setting that field in the parent. */
5612 /* Before assigning a value in an aggregate make sure range checks
5613 are done if required. Then convert to the type of the field. */
5619 /* Add the field and expression to the list. */
5621 }
5625 #ifdef ENABLE_CHECKING
5626 {
5627 tree gnu_field;
5629 /* Verify every enty in GNU_LIST was used. */
5632 }
5633 #endif
5636 }
5638 /* Builds a possibly nested constructor for array aggregates. GNAT_EXPR
5639 is the first element of an array aggregate. It may itself be an
5640 aggregate (an array or record aggregate). GNU_ARRAY_TYPE is the gnu type
5641 corresponding to the array aggregate. GNAT_COMPONENT_TYPE is the type
5642 of the array component. It is needed for range checking. */
5644 static tree
5646 Entity_Id gnat_component_type)
5647 {
5650 tree gnu_expr;
5653 {
5654 /* If the expression is itself an array aggregate then first build the
5655 innermost constructor if it is part of our array (multi-dimensional
5656 case). */
5663 gnat_component_type);
5664 else
5665 {
5668 /* before assigning the element to the array make sure it is
5669 in range */
5672 }
5674 gnu_expr_list
5676 gnu_expr_list);
5679 }
5682 }
5683 \f
5684 /* Subroutine of assoc_to_constructor: VALUES is a list of field associations,
5685 some of which are from RECORD_TYPE. Return a CONSTRUCTOR consisting
5686 of the associations that are from RECORD_TYPE. If we see an internal
5687 record, make a recursive call to fill it in as well. */
5689 static tree
5691 {
5696 {
5699 /* _Parent is an internal field, but may have values in the aggregate,
5700 so check for values first. */
5702 {
5705 }
5708 {
5713 }
5714 else
5715 /* If we have a record subtype, the names will match, but not the
5716 actual FIELD_DECLs. */
5719 {
5722 }
5728 }
5731 }
5732 \f
5733 /* EXP is to be treated as an array or record. Handle the cases when it is
5734 an access object and perform the required dereferences. */
5736 static tree
5738 {
5739 /* If the type is a pointer, dereference it. */
5744 /* If we got a padded type, remove it too. */
5750 }
5751 \f
5752 /* Protect EXP from multiple evaluation. This may make a SAVE_EXPR. */
5754 tree
5756 {
5759 /* If this has no side effects, we don't need to do anything. */
5763 /* If it is a conversion, protect what's inside the conversion.
5764 Similarly, if we're indirectly referencing something, we only
5765 actually need to protect the address since the data itself can't
5766 change in these situations. */
5775 /* If EXP is a fat pointer or something that can be placed into a register,
5776 just make a SAVE_EXPR. */
5780 /* Otherwise, dereference, protect the address, and re-reference. */
5781 else
5782 return
5786 exp)));
5787 }
5788 \f
5789 /* This is equivalent to stabilize_reference in GCC's tree.c, but we know how
5790 to handle our new nodes and we take extra arguments:
5792 FORCE says whether to force evaluation of everything,
5794 SUCCESS we set to true unless we walk through something we don't know how
5795 to stabilize, or through something which is not an lvalue and LVALUES_ONLY
5796 is true, in which cases we set to false. */
5798 tree
5801 {
5804 tree result;
5806 /* Assume we'll success unless proven otherwise. */
5810 {
5814 /* No action is needed in this case. */
5818 /* A standalone ADDR_EXPR is never an lvalue, and this one can't
5819 be nested inside an outer INDIRECT_REF, since INDIREC_REF goes
5820 straight to stabilize_1. */
5824 /* ... Fallthru ... */
5834 result
5844 force));
5859 force),
5861 force));
5870 force),
5877 force),
5885 /* ... Fallthru to failure ... */
5887 /* If arg isn't a kind of lvalue we recognize, make no change.
5888 Caller should recognize the error for an invalid lvalue. */
5890 failure:
5893 }
5897 /* TREE_THIS_VOLATILE and TREE_SIDE_EFFECTS attached to the initial
5898 expression may not be sustained across some paths, such as the way via
5899 build1 for INDIRECT_REF. We re-populate those flags here for the general
5900 case, which is consistent with the GCC version of this routine.
5902 Special care should be taken regarding TREE_SIDE_EFFECTS, because some
5903 paths introduce side effects where there was none initially (e.g. calls
5904 to save_expr), and we also want to keep track of that. */
5910 }
5912 /* Wrapper around maybe_stabilize_reference, for common uses without
5913 lvalue restrictions and without need to examine the success
5914 indication. */
5916 tree
5918 {
5921 }
5923 /* Similar to stabilize_reference_1 in tree.c, but supports an extra
5924 arg to force a SAVE_EXPR for everything. */
5926 static tree
5928 {
5931 tree result;
5933 /* We cannot ignore const expressions because it might be a reference
5934 to a const array but whose index contains side-effects. But we can
5935 ignore things that are actual constant or that already have been
5936 handled by this function. */
5942 {
5950 /* If this is a COMPONENT_REF of a fat pointer, save the entire
5951 fat pointer. This may be more efficient, but will also allow
5952 us to more easily find the match for the PLACEHOLDER_EXPR. */
5957 force),
5961 else
5966 /* Constants need no processing. In fact, we should never reach
5967 here. */
5971 /* Recursively stabilize each operand. */
5975 force));
5979 /* Recursively stabilize each operand. */
5982 force));
5987 }
5994 }
5996 /* Build a global constructor or destructor function. METHOD_TYPE gives
5997 the type of the function and CDTORS points to the list of constructor
5998 or destructor functions to be invoked. FIXME: Migrate into cgraph. */
6000 static void
6002 {
6006 {
6011 NULL_TREE);
6013 }
6016 }
6017 \f
6020 /* Convert Sloc into *LOCUS (a location_t). Return true if this Sloc
6021 corresponds to a source code location and false if it doesn't. In the
6022 latter case, we don't update *LOCUS. We also set the Gigi global variable
6023 REF_FILENAME to the reference file name as given by sinput (i.e no
6024 directory). */
6026 bool
6028 {
6029 /* If node not from source code, ignore. */
6033 /* Use the identifier table to make a hashed, permanent copy of the filename,
6034 since the name table gets reallocated after Gigi returns but before all
6035 the debugging information is output. The __gnat_to_canonical_file_spec
6036 call translates filenames from pragmas Source_Reference that contain host
6037 style syntax not understood by gdb. */
6038 locus->file
6039 = IDENTIFIER_POINTER
6040 (get_identifier
6041 (__gnat_to_canonical_file_spec
6046 ref_filename
6047 = IDENTIFIER_POINTER
6048 (get_identifier
6052 }
6054 /* Similar to annotate_with_locus, but start with the Sloc of GNAT_NODE and
6055 don't do anything if it doesn't correspond to a source location. */
6057 static void
6059 {
6060 location_t locus;
6066 }
6067 \f
6068 /* Post an error message. MSG is the error message, properly annotated.
6069 NODE is the node at which to post the error and the node to use for the
6070 "&" substitution. */
6072 void
6074 {
6075 String_Template temp;
6076 Fat_Pointer fp;
6082 }
6084 /* Similar, but NODE is the node at which to post the error and ENT
6085 is the node to use for the "&" substitution. */
6087 void
6089 {
6090 String_Template temp;
6091 Fat_Pointer fp;
6097 }
6099 /* Similar, but NODE is the node at which to post the error, ENT is the node
6100 to use for the "&" substitution, and N is the number to use for the ^. */
6102 void
6104 {
6105 String_Template temp;
6106 Fat_Pointer fp;
6114 }
6115 \f
6116 /* Similar to post_error_ne_num, but T is a GCC tree representing the
6117 number to write. If the tree represents a constant that fits within
6118 a host integer, the text inside curly brackets in MSG will be output
6119 (presumably including a '^'). Otherwise that text will not be output
6120 and the text inside square brackets will be output instead. */
6122 void
6124 {
6127 Fat_Pointer fp;
6135 #if HOST_BITS_PER_WIDE_INT > HOST_BITS_PER_INT
6136 &&
6137 compare_tree_int
6139 #endif
6140 )
6141 {
6144 }
6145 else
6149 {
6155 ;
6156 else
6158 }
6165 }
6167 /* Similar to post_error_ne_tree, except that NUM is a second
6168 integer to write in the message. */
6170 void
6172 Node_Id node,
6173 Entity_Id ent,
6174 tree t,
6176 {
6179 }
6180 \f
6181 /* Initialize the table that maps GNAT codes to GCC codes for simple
6182 binary and unary operations. */
6184 void
6186 {
6212 }