1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2010, Free Software Foundation, Inc. *
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 3, 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 COPYING3. If not see *
19 * <http://www.gnu.org/licenses/>. *
21 * GNAT was originally developed by the GNAT team at New York University. *
22 * Extensive contributions were provided by Ada Core Technologies Inc. *
24 ****************************************************************************/
26 /* This file contains parts of the compiler that are required for interfacing
27 with GCC but otherwise do nothing and parts of Gigi that need to know
32 #include "coretypes.h"
35 #include "diagnostic.h"
41 #include "langhooks.h"
42 #include "langhooks-def.h"
46 #include "function.h" /* For pass_by_reference. */
49 #include "adadecode.h"
63 static bool gnat_init (void);
64 static unsigned int gnat_option_lang_mask (void);
65 static void gnat_init_options (unsigned int,
66 struct cl_decoded_option *);
67 static int gnat_handle_option (size_t, const char *, int, int);
68 static bool gnat_post_options (const char **);
69 static alias_set_type gnat_get_alias_set (tree);
70 static void gnat_print_decl (FILE *, tree, int);
71 static void gnat_print_type (FILE *, tree, int);
72 static const char *gnat_printable_name (tree, int);
73 static const char *gnat_dwarf_name (tree, int);
74 static tree gnat_return_tree (tree);
75 static void gnat_parse_file (int);
76 static void internal_error_function (diagnostic_context *,
77 const char *, va_list *);
78 static tree gnat_type_max_size (const_tree);
79 static void gnat_get_subrange_bounds (const_tree, tree *, tree *);
80 static tree gnat_eh_personality (void);
82 /* Definitions for our language-specific hooks. */
84 #undef LANG_HOOKS_NAME
85 #define LANG_HOOKS_NAME "GNU Ada"
86 #undef LANG_HOOKS_IDENTIFIER_SIZE
87 #define LANG_HOOKS_IDENTIFIER_SIZE sizeof (struct tree_identifier)
88 #undef LANG_HOOKS_INIT
89 #define LANG_HOOKS_INIT gnat_init
90 #undef LANG_HOOKS_OPTION_LANG_MASK
91 #define LANG_HOOKS_OPTION_LANG_MASK gnat_option_lang_mask
92 #undef LANG_HOOKS_INIT_OPTIONS
93 #define LANG_HOOKS_INIT_OPTIONS gnat_init_options
94 #undef LANG_HOOKS_HANDLE_OPTION
95 #define LANG_HOOKS_HANDLE_OPTION gnat_handle_option
96 #undef LANG_HOOKS_POST_OPTIONS
97 #define LANG_HOOKS_POST_OPTIONS gnat_post_options
98 #undef LANG_HOOKS_PARSE_FILE
99 #define LANG_HOOKS_PARSE_FILE gnat_parse_file
100 #undef LANG_HOOKS_HASH_TYPES
101 #define LANG_HOOKS_HASH_TYPES false
102 #undef LANG_HOOKS_GETDECLS
103 #define LANG_HOOKS_GETDECLS lhd_return_null_tree_v
104 #undef LANG_HOOKS_PUSHDECL
105 #define LANG_HOOKS_PUSHDECL gnat_return_tree
106 #undef LANG_HOOKS_WRITE_GLOBALS
107 #define LANG_HOOKS_WRITE_GLOBALS gnat_write_global_declarations
108 #undef LANG_HOOKS_GET_ALIAS_SET
109 #define LANG_HOOKS_GET_ALIAS_SET gnat_get_alias_set
110 #undef LANG_HOOKS_PRINT_DECL
111 #define LANG_HOOKS_PRINT_DECL gnat_print_decl
112 #undef LANG_HOOKS_PRINT_TYPE
113 #define LANG_HOOKS_PRINT_TYPE gnat_print_type
114 #undef LANG_HOOKS_TYPE_MAX_SIZE
115 #define LANG_HOOKS_TYPE_MAX_SIZE gnat_type_max_size
116 #undef LANG_HOOKS_DECL_PRINTABLE_NAME
117 #define LANG_HOOKS_DECL_PRINTABLE_NAME gnat_printable_name
118 #undef LANG_HOOKS_DWARF_NAME
119 #define LANG_HOOKS_DWARF_NAME gnat_dwarf_name
120 #undef LANG_HOOKS_GIMPLIFY_EXPR
121 #define LANG_HOOKS_GIMPLIFY_EXPR gnat_gimplify_expr
122 #undef LANG_HOOKS_TYPE_FOR_MODE
123 #define LANG_HOOKS_TYPE_FOR_MODE gnat_type_for_mode
124 #undef LANG_HOOKS_TYPE_FOR_SIZE
125 #define LANG_HOOKS_TYPE_FOR_SIZE gnat_type_for_size
126 #undef LANG_HOOKS_TYPES_COMPATIBLE_P
127 #define LANG_HOOKS_TYPES_COMPATIBLE_P gnat_types_compatible_p
128 #undef LANG_HOOKS_GET_SUBRANGE_BOUNDS
129 #define LANG_HOOKS_GET_SUBRANGE_BOUNDS gnat_get_subrange_bounds
130 #undef LANG_HOOKS_ATTRIBUTE_TABLE
131 #define LANG_HOOKS_ATTRIBUTE_TABLE gnat_internal_attribute_table
132 #undef LANG_HOOKS_BUILTIN_FUNCTION
133 #define LANG_HOOKS_BUILTIN_FUNCTION gnat_builtin_function
134 #undef LANG_HOOKS_EH_PERSONALITY
135 #define LANG_HOOKS_EH_PERSONALITY gnat_eh_personality
136 #undef LANG_HOOKS_DEEP_UNSHARING
137 #define LANG_HOOKS_DEEP_UNSHARING true
139 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
141 /* This symbol needs to be defined for the front-end. */
142 void *callgraph_info_file = NULL;
144 /* How much we want of our DWARF extensions. Some of our dwarf+ extensions
145 are incompatible with regular GDB versions, so we must make sure to only
146 produce them on explicit request. This is eventually reflected into the
147 use_gnu_debug_info_extensions common flag for later processing. */
148 static int gnat_dwarf_extensions = 0;
150 /* Command-line argc and argv. These variables are global
151 since they are imported in back_end.adb. */
152 unsigned int save_argc;
153 const char **save_argv;
155 /* GNAT argc and argv. */
156 extern int gnat_argc;
157 extern char **gnat_argv;
159 /* Declare functions we use as part of startup. */
160 extern void __gnat_initialize (void *);
161 extern void __gnat_install_SEH_handler (void *);
162 extern void adainit (void);
163 extern void _ada_gnat1drv (void);
165 /* The parser for the language. For us, we process the GNAT tree. */
168 gnat_parse_file (int set_yydebug ATTRIBUTE_UNUSED)
172 /* Call the target specific initializations. */
173 __gnat_initialize (NULL);
175 /* ??? Call the SEH initialization routine. This is to workaround
176 a bootstrap path problem. The call below should be removed at some
177 point and the SEH pointer passed to __gnat_initialize() above. */
178 __gnat_install_SEH_handler((void *)seh);
180 /* Call the front-end elaboration procedures. */
183 /* Call the front end. */
187 /* Decode all the language specific options that cannot be decoded by GCC.
188 The option decoding phase of GCC calls this routine on the flags that
189 it cannot decode. Return the number of consecutive arguments from ARGV
190 that have been successfully decoded or 0 on failure. */
193 gnat_handle_option (size_t scode, const char *arg, int value,
194 int kind ATTRIBUTE_UNUSED)
196 const struct cl_option *option = &cl_options[scode];
197 enum opt_code code = (enum opt_code) scode;
199 if (arg == NULL && (option->flags & (CL_JOINED | CL_SEPARATE)))
201 error ("missing argument to \"-%s\"", option->opt_text);
209 warn_uninitialized = value;
212 case OPT_Wmissing_prototypes:
213 case OPT_Wstrict_prototypes:
214 case OPT_Wwrite_strings:
216 case OPT_Wvariadic_macros:
217 case OPT_Wold_style_definition:
218 case OPT_Wmissing_format_attribute:
219 case OPT_Woverlength_strings:
220 /* These are used in the GCC Makefile. */
223 case OPT_feliminate_unused_debug_types:
224 /* We arrange for post_option to be able to only set the corresponding
225 flag to 1 when explicitly requested by the user. We expect the
226 default flag value to be either 0 or positive, and expose a positive
227 -f as a negative value to post_option. */
228 flag_eliminate_unused_debug_types = -value;
232 gnat_dwarf_extensions = 1;
236 warning (0, "%<-gnat%> misspelled as %<-gant%>");
238 /* ... fall through ... */
246 /* These are handled by the front-end. */
256 /* Return language mask for option processing. */
259 gnat_option_lang_mask (void)
264 /* Initialize for option processing. */
267 gnat_init_options (unsigned int decoded_options_count,
268 struct cl_decoded_option *decoded_options)
270 /* Reconstruct an argv array for use of back_end.adb.
272 ??? back_end.adb should not rely on this; instead, it should work
273 with decoded options without such reparsing, to ensure
274 consistency in how options are decoded. */
277 save_argv = XNEWVEC (const char *, 2 * decoded_options_count + 1);
279 for (i = 0; i < decoded_options_count; i++)
281 save_argv[save_argc++] = decoded_options[i].canonical_option[0];
282 if (decoded_options[i].canonical_option[1] != NULL)
283 save_argv[save_argc++] = decoded_options[i].canonical_option[1];
285 save_argv[save_argc] = NULL;
287 gnat_argv = (char **) xmalloc (sizeof (save_argv[0]));
288 gnat_argv[0] = xstrdup (save_argv[0]); /* name of the command */
291 /* Uninitialized really means uninitialized in Ada. */
292 flag_zero_initialized_in_bss = 0;
295 /* Post-switch processing. */
298 gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)
300 /* Excess precision other than "fast" requires front-end
302 if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD
303 && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)
304 sorry ("-fexcess-precision=standard for Ada");
305 flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
307 /* ??? The warning machinery is outsmarted by Ada. */
308 warn_unused_parameter = 0;
310 /* No psABI change warnings for Ada. */
313 /* Force eliminate_unused_debug_types to 0 unless an explicit positive
314 -f has been passed. This forces the default to 0 for Ada, which might
315 differ from the common default. */
316 if (flag_eliminate_unused_debug_types < 0)
317 flag_eliminate_unused_debug_types = 1;
319 flag_eliminate_unused_debug_types = 0;
321 /* Reflect the explicit request of DWARF extensions into the common
322 flag for use by later passes. */
323 if (write_symbols == DWARF2_DEBUG)
324 use_gnu_debug_info_extensions = gnat_dwarf_extensions > 0;
329 /* Here is the function to handle the compiler error processing in GCC. */
332 internal_error_function (diagnostic_context *context,
333 const char *msgid, va_list *ap)
336 char *buffer, *p, *loc;
337 String_Template temp, temp_loc;
338 Fat_Pointer fp, fp_loc;
341 /* Warn if plugins present. */
344 /* Reset the pretty-printer. */
345 pp_clear_output_area (context->printer);
347 /* Format the message into the pretty-printer. */
348 tinfo.format_spec = msgid;
350 tinfo.err_no = errno;
351 pp_format_verbatim (context->printer, &tinfo);
353 /* Extract a (writable) pointer to the formatted text. */
354 buffer = xstrdup (pp_formatted_text (context->printer));
356 /* Go up to the first newline. */
357 for (p = buffer; *p; p++)
365 temp.High_Bound = p - buffer;
369 s = expand_location (input_location);
370 if (context->show_column && s.column != 0)
371 asprintf (&loc, "%s:%d:%d", s.file, s.line, s.column);
373 asprintf (&loc, "%s:%d", s.file, s.line);
374 temp_loc.Low_Bound = 1;
375 temp_loc.High_Bound = strlen (loc);
376 fp_loc.Bounds = &temp_loc;
379 Current_Error_Node = error_gnat_node;
380 Compiler_Abort (fp, -1, fp_loc);
383 /* Perform all the initialization steps that are language-specific. */
388 /* Do little here, most of the standard declarations are set up after the
389 front-end has been run. Use the same `char' as C, this doesn't really
390 matter since we'll use the explicit `unsigned char' for Character. */
391 build_common_tree_nodes (flag_signed_char);
393 /* In Ada, we use the unsigned type corresponding to the width of Pmode as
394 SIZETYPE. In most cases when ptr_mode and Pmode differ, C will use the
395 width of ptr_mode for SIZETYPE, but we get better code using the width
396 of Pmode. Note that, although we manipulate negative offsets for some
397 internal constructs and rely on compile time overflow detection in size
398 computations, using unsigned types for SIZETYPEs is fine since they are
399 treated specially by the middle-end, in particular sign-extended. */
400 size_type_node = gnat_type_for_mode (Pmode, 1);
401 set_sizetype (size_type_node);
402 TYPE_NAME (sizetype) = get_identifier ("size_type");
404 /* In Ada, we use an unsigned 8-bit type for the default boolean type. */
405 boolean_type_node = make_unsigned_type (8);
406 TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
407 SET_TYPE_RM_MAX_VALUE (boolean_type_node,
408 build_int_cst (boolean_type_node, 1));
409 SET_TYPE_RM_SIZE (boolean_type_node, bitsize_int (1));
411 build_common_tree_nodes_2 (0);
412 sbitsize_one_node = sbitsize_int (1);
413 sbitsize_unit_node = sbitsize_int (BITS_PER_UNIT);
414 boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
416 ptr_void_type_node = build_pointer_type (void_type_node);
418 /* Show that REFERENCE_TYPEs are internal and should be Pmode. */
419 internal_reference_types ();
421 /* Register our internal error function. */
422 global_dc->internal_error = &internal_error_function;
427 /* If we are using the GCC mechanism to process exception handling, we
428 have to register the personality routine for Ada and to initialize
429 various language dependent hooks. */
432 gnat_init_gcc_eh (void)
434 #ifdef DWARF2_UNWIND_INFO
435 /* lang_dependent_init already called dwarf2out_frame_init if true. */
436 int dwarf2out_frame_initialized = dwarf2out_do_frame ();
439 /* We shouldn't do anything if the No_Exceptions_Handler pragma is set,
440 though. This could for instance lead to the emission of tables with
441 references to symbols (such as the Ada eh personality routine) within
442 libraries we won't link against. */
443 if (No_Exception_Handlers_Set ())
446 /* Tell GCC we are handling cleanup actions through exception propagation.
447 This opens possibilities that we don't take advantage of yet, but is
448 nonetheless necessary to ensure that fixup code gets assigned to the
449 right exception regions. */
450 using_eh_for_cleanups ();
452 /* Turn on -fexceptions and -fnon-call-exceptions. The first one triggers
453 the generation of the necessary exception tables. The second one is
454 useful for two reasons: 1/ we map some asynchronous signals like SEGV to
455 exceptions, so we need to ensure that the insns which can lead to such
456 signals are correctly attached to the exception region they pertain to,
457 2/ Some calls to pure subprograms are handled as libcall blocks and then
458 marked as "cannot trap" if the flag is not set (see emit_libcall_block).
459 We should not let this be since it is possible for such calls to actually
462 flag_non_call_exceptions = 1;
465 #ifdef DWARF2_UNWIND_INFO
466 if (!dwarf2out_frame_initialized && dwarf2out_do_frame ())
467 dwarf2out_frame_init ();
471 /* Print language-specific items in declaration NODE. */
474 gnat_print_decl (FILE *file, tree node, int indent)
476 switch (TREE_CODE (node))
479 print_node (file, "corresponding var",
480 DECL_CONST_CORRESPONDING_VAR (node), indent + 4);
484 print_node (file, "original field", DECL_ORIGINAL_FIELD (node),
489 print_node (file, "renamed object", DECL_RENAMED_OBJECT (node),
498 /* Print language-specific items in type NODE. */
501 gnat_print_type (FILE *file, tree node, int indent)
503 switch (TREE_CODE (node))
506 print_node (file, "ci/co list", TYPE_CI_CO_LIST (node), indent + 4);
510 if (TYPE_MODULAR_P (node))
511 print_node_brief (file, "modulus", TYPE_MODULUS (node), indent + 4);
512 else if (TYPE_HAS_ACTUAL_BOUNDS_P (node))
513 print_node (file, "actual bounds", TYPE_ACTUAL_BOUNDS (node),
515 else if (TYPE_VAX_FLOATING_POINT_P (node))
518 print_node (file, "index type", TYPE_INDEX_TYPE (node), indent + 4);
520 /* ... fall through ... */
524 print_node_brief (file, "RM size", TYPE_RM_SIZE (node), indent + 4);
526 /* ... fall through ... */
529 print_node_brief (file, "RM min", TYPE_RM_MIN_VALUE (node), indent + 4);
530 print_node_brief (file, "RM max", TYPE_RM_MAX_VALUE (node), indent + 4);
534 print_node (file,"actual bounds", TYPE_ACTUAL_BOUNDS (node), indent + 4);
538 print_node (file,"representative array",
539 TYPE_REPRESENTATIVE_ARRAY (node), indent + 4);
543 if (TYPE_FAT_POINTER_P (node) || TYPE_CONTAINS_TEMPLATE_P (node))
544 print_node (file, "unconstrained array",
545 TYPE_UNCONSTRAINED_ARRAY (node), indent + 4);
547 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
551 case QUAL_UNION_TYPE:
552 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
560 /* Return the name to be printed for DECL. */
563 gnat_printable_name (tree decl, int verbosity)
565 const char *coded_name = IDENTIFIER_POINTER (DECL_NAME (decl));
566 char *ada_name = (char *) ggc_alloc_atomic (strlen (coded_name) * 2 + 60);
568 __gnat_decode (coded_name, ada_name, 0);
570 if (verbosity == 2 && !DECL_IS_BUILTIN (decl))
572 Set_Identifier_Casing (ada_name, DECL_SOURCE_FILE (decl));
573 return ggc_strdup (Name_Buffer);
579 /* Return the name to be used in DWARF debug info for DECL. */
582 gnat_dwarf_name (tree decl, int verbosity ATTRIBUTE_UNUSED)
584 gcc_assert (DECL_P (decl));
585 return (const char *) IDENTIFIER_POINTER (DECL_NAME (decl));
588 /* Do nothing (return the tree node passed). */
591 gnat_return_tree (tree t)
596 /* Get the alias set corresponding to a type or expression. */
598 static alias_set_type
599 gnat_get_alias_set (tree type)
601 /* If this is a padding type, use the type of the first field. */
602 if (TYPE_IS_PADDING_P (type))
603 return get_alias_set (TREE_TYPE (TYPE_FIELDS (type)));
605 /* If the type is an unconstrained array, use the type of the
606 self-referential array we make. */
607 else if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
609 get_alias_set (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))));
611 /* If the type can alias any other types, return the alias set 0. */
612 else if (TYPE_P (type)
613 && TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (type)))
619 /* GNU_TYPE is a type. Return its maximum size in bytes, if known,
620 as a constant when possible. */
623 gnat_type_max_size (const_tree gnu_type)
625 /* First see what we can get from TYPE_SIZE_UNIT, which might not
626 be constant even for simple expressions if it has already been
627 elaborated and possibly replaced by a VAR_DECL. */
628 tree max_unitsize = max_size (TYPE_SIZE_UNIT (gnu_type), true);
630 /* If we don't have a constant, see what we can get from TYPE_ADA_SIZE,
631 which should stay untouched. */
632 if (!host_integerp (max_unitsize, 1)
633 && (TREE_CODE (gnu_type) == RECORD_TYPE
634 || TREE_CODE (gnu_type) == UNION_TYPE
635 || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
636 && TYPE_ADA_SIZE (gnu_type))
638 tree max_adasize = max_size (TYPE_ADA_SIZE (gnu_type), true);
640 /* If we have succeeded in finding a constant, round it up to the
641 type's alignment and return the result in units. */
642 if (host_integerp (max_adasize, 1))
644 = size_binop (CEIL_DIV_EXPR,
645 round_up (max_adasize, TYPE_ALIGN (gnu_type)),
652 /* GNU_TYPE is a subtype of an integral type. Set LOWVAL to the low bound
653 and HIGHVAL to the high bound, respectively. */
656 gnat_get_subrange_bounds (const_tree gnu_type, tree *lowval, tree *highval)
658 *lowval = TYPE_MIN_VALUE (gnu_type);
659 *highval = TYPE_MAX_VALUE (gnu_type);
662 /* GNU_TYPE is a type. Determine if it should be passed by reference by
666 default_pass_by_ref (tree gnu_type)
668 /* We pass aggregates by reference if they are sufficiently large. The
669 choice of constant here is somewhat arbitrary. We also pass by
670 reference if the target machine would either pass or return by
671 reference. Strictly speaking, we need only check the return if this
672 is an In Out parameter, but it's probably best to err on the side of
673 passing more things by reference. */
675 if (pass_by_reference (NULL, TYPE_MODE (gnu_type), gnu_type, 1))
678 if (targetm.calls.return_in_memory (gnu_type, NULL_TREE))
681 if (AGGREGATE_TYPE_P (gnu_type)
682 && (!host_integerp (TYPE_SIZE (gnu_type), 1)
683 || 0 < compare_tree_int (TYPE_SIZE (gnu_type),
684 8 * TYPE_ALIGN (gnu_type))))
690 /* GNU_TYPE is the type of a subprogram parameter. Determine from the type if
691 it should be passed by reference. */
694 must_pass_by_ref (tree gnu_type)
696 /* We pass only unconstrained objects, those required by the language
697 to be passed by reference, and objects of variable size. The latter
698 is more efficient, avoids problems with variable size temporaries,
699 and does not produce compatibility problems with C, since C does
700 not have such objects. */
701 return (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
702 || TREE_ADDRESSABLE (gnu_type)
703 || (TYPE_SIZE (gnu_type)
704 && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));
707 /* Return the size of the FP mode with precision PREC. */
710 fp_prec_to_size (int prec)
712 enum machine_mode mode;
714 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
715 mode = GET_MODE_WIDER_MODE (mode))
716 if (GET_MODE_PRECISION (mode) == prec)
717 return GET_MODE_BITSIZE (mode);
722 /* Return the precision of the FP mode with size SIZE. */
725 fp_size_to_prec (int size)
727 enum machine_mode mode;
729 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
730 mode = GET_MODE_WIDER_MODE (mode))
731 if (GET_MODE_BITSIZE (mode) == size)
732 return GET_MODE_PRECISION (mode);
737 static GTY(()) tree gnat_eh_personality_decl;
740 gnat_eh_personality (void)
742 if (!gnat_eh_personality_decl)
743 gnat_eh_personality_decl
744 = build_personality_function (USING_SJLJ_EXCEPTIONS
745 ? "__gnat_eh_personality_sj"
746 : "__gnat_eh_personality");
748 return gnat_eh_personality_decl;
751 #include "gt-ada-misc.h"