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 bool gnat_handle_option (size_t, const char *, int, int,
68 const struct cl_option_handlers *);
69 static bool gnat_post_options (const char **);
70 static alias_set_type gnat_get_alias_set (tree);
71 static void gnat_print_decl (FILE *, tree, int);
72 static void gnat_print_type (FILE *, tree, int);
73 static const char *gnat_printable_name (tree, int);
74 static const char *gnat_dwarf_name (tree, int);
75 static tree gnat_return_tree (tree);
76 static void gnat_parse_file (int);
77 static void internal_error_function (diagnostic_context *,
78 const char *, va_list *);
79 static tree gnat_type_max_size (const_tree);
80 static void gnat_get_subrange_bounds (const_tree, tree *, tree *);
81 static tree gnat_eh_personality (void);
83 /* Definitions for our language-specific hooks. */
85 #undef LANG_HOOKS_NAME
86 #define LANG_HOOKS_NAME "GNU Ada"
87 #undef LANG_HOOKS_IDENTIFIER_SIZE
88 #define LANG_HOOKS_IDENTIFIER_SIZE sizeof (struct tree_identifier)
89 #undef LANG_HOOKS_INIT
90 #define LANG_HOOKS_INIT gnat_init
91 #undef LANG_HOOKS_OPTION_LANG_MASK
92 #define LANG_HOOKS_OPTION_LANG_MASK gnat_option_lang_mask
93 #undef LANG_HOOKS_INIT_OPTIONS
94 #define LANG_HOOKS_INIT_OPTIONS gnat_init_options
95 #undef LANG_HOOKS_HANDLE_OPTION
96 #define LANG_HOOKS_HANDLE_OPTION gnat_handle_option
97 #undef LANG_HOOKS_POST_OPTIONS
98 #define LANG_HOOKS_POST_OPTIONS gnat_post_options
99 #undef LANG_HOOKS_PARSE_FILE
100 #define LANG_HOOKS_PARSE_FILE gnat_parse_file
101 #undef LANG_HOOKS_HASH_TYPES
102 #define LANG_HOOKS_HASH_TYPES false
103 #undef LANG_HOOKS_GETDECLS
104 #define LANG_HOOKS_GETDECLS lhd_return_null_tree_v
105 #undef LANG_HOOKS_PUSHDECL
106 #define LANG_HOOKS_PUSHDECL gnat_return_tree
107 #undef LANG_HOOKS_WRITE_GLOBALS
108 #define LANG_HOOKS_WRITE_GLOBALS gnat_write_global_declarations
109 #undef LANG_HOOKS_GET_ALIAS_SET
110 #define LANG_HOOKS_GET_ALIAS_SET gnat_get_alias_set
111 #undef LANG_HOOKS_PRINT_DECL
112 #define LANG_HOOKS_PRINT_DECL gnat_print_decl
113 #undef LANG_HOOKS_PRINT_TYPE
114 #define LANG_HOOKS_PRINT_TYPE gnat_print_type
115 #undef LANG_HOOKS_TYPE_MAX_SIZE
116 #define LANG_HOOKS_TYPE_MAX_SIZE gnat_type_max_size
117 #undef LANG_HOOKS_DECL_PRINTABLE_NAME
118 #define LANG_HOOKS_DECL_PRINTABLE_NAME gnat_printable_name
119 #undef LANG_HOOKS_DWARF_NAME
120 #define LANG_HOOKS_DWARF_NAME gnat_dwarf_name
121 #undef LANG_HOOKS_GIMPLIFY_EXPR
122 #define LANG_HOOKS_GIMPLIFY_EXPR gnat_gimplify_expr
123 #undef LANG_HOOKS_TYPE_FOR_MODE
124 #define LANG_HOOKS_TYPE_FOR_MODE gnat_type_for_mode
125 #undef LANG_HOOKS_TYPE_FOR_SIZE
126 #define LANG_HOOKS_TYPE_FOR_SIZE gnat_type_for_size
127 #undef LANG_HOOKS_TYPES_COMPATIBLE_P
128 #define LANG_HOOKS_TYPES_COMPATIBLE_P gnat_types_compatible_p
129 #undef LANG_HOOKS_GET_SUBRANGE_BOUNDS
130 #define LANG_HOOKS_GET_SUBRANGE_BOUNDS gnat_get_subrange_bounds
131 #undef LANG_HOOKS_ATTRIBUTE_TABLE
132 #define LANG_HOOKS_ATTRIBUTE_TABLE gnat_internal_attribute_table
133 #undef LANG_HOOKS_BUILTIN_FUNCTION
134 #define LANG_HOOKS_BUILTIN_FUNCTION gnat_builtin_function
135 #undef LANG_HOOKS_EH_PERSONALITY
136 #define LANG_HOOKS_EH_PERSONALITY gnat_eh_personality
137 #undef LANG_HOOKS_DEEP_UNSHARING
138 #define LANG_HOOKS_DEEP_UNSHARING true
140 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
142 /* This symbol needs to be defined for the front-end. */
143 void *callgraph_info_file = NULL;
145 /* How much we want of our DWARF extensions. Some of our dwarf+ extensions
146 are incompatible with regular GDB versions, so we must make sure to only
147 produce them on explicit request. This is eventually reflected into the
148 use_gnu_debug_info_extensions common flag for later processing. */
149 static int gnat_dwarf_extensions = 0;
151 /* Command-line argc and argv. These variables are global
152 since they are imported in back_end.adb. */
153 unsigned int save_argc;
154 const char **save_argv;
156 /* GNAT argc and argv. */
157 extern int gnat_argc;
158 extern char **gnat_argv;
160 /* Declare functions we use as part of startup. */
161 extern void __gnat_initialize (void *);
162 extern void __gnat_install_SEH_handler (void *);
163 extern void adainit (void);
164 extern void _ada_gnat1drv (void);
166 /* The parser for the language. For us, we process the GNAT tree. */
169 gnat_parse_file (int set_yydebug ATTRIBUTE_UNUSED)
173 /* Call the target specific initializations. */
174 __gnat_initialize (NULL);
176 /* ??? Call the SEH initialization routine. This is to workaround
177 a bootstrap path problem. The call below should be removed at some
178 point and the SEH pointer passed to __gnat_initialize() above. */
179 __gnat_install_SEH_handler((void *)seh);
181 /* Call the front-end elaboration procedures. */
184 /* Call the front end. */
188 /* Decode all the language specific options that cannot be decoded by GCC.
189 The option decoding phase of GCC calls this routine on the flags that
190 are marked as Ada-specific. Return true on success or false on failure. */
193 gnat_handle_option (size_t scode, const char *arg ATTRIBUTE_UNUSED, int value,
194 int kind ATTRIBUTE_UNUSED,
195 const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
197 enum opt_code code = (enum opt_code) scode;
203 warn_uninitialized = value;
206 case OPT_Wmissing_prototypes:
207 case OPT_Wstrict_prototypes:
208 case OPT_Wwrite_strings:
210 case OPT_Wvariadic_macros:
211 case OPT_Wold_style_definition:
212 case OPT_Wmissing_format_attribute:
213 case OPT_Woverlength_strings:
214 /* These are used in the GCC Makefile. */
217 case OPT_feliminate_unused_debug_types:
218 /* We arrange for post_option to be able to only set the corresponding
219 flag to 1 when explicitly requested by the user. We expect the
220 default flag value to be either 0 or positive, and expose a positive
221 -f as a negative value to post_option. */
222 flag_eliminate_unused_debug_types = -value;
226 gnat_dwarf_extensions = 1;
230 warning (0, "%<-gnat%> misspelled as %<-gant%>");
232 /* ... fall through ... */
240 /* These are handled by the front-end. */
250 /* Return language mask for option processing. */
253 gnat_option_lang_mask (void)
258 /* Initialize for option processing. */
261 gnat_init_options (unsigned int decoded_options_count,
262 struct cl_decoded_option *decoded_options)
264 /* Reconstruct an argv array for use of back_end.adb.
266 ??? back_end.adb should not rely on this; instead, it should work
267 with decoded options without such reparsing, to ensure
268 consistency in how options are decoded. */
271 save_argv = XNEWVEC (const char *, 2 * decoded_options_count + 1);
273 for (i = 0; i < decoded_options_count; i++)
275 save_argv[save_argc++] = decoded_options[i].canonical_option[0];
276 if (decoded_options[i].canonical_option[1] != NULL)
277 save_argv[save_argc++] = decoded_options[i].canonical_option[1];
279 save_argv[save_argc] = NULL;
281 gnat_argv = (char **) xmalloc (sizeof (save_argv[0]));
282 gnat_argv[0] = xstrdup (save_argv[0]); /* name of the command */
285 /* Uninitialized really means uninitialized in Ada. */
286 flag_zero_initialized_in_bss = 0;
289 /* Post-switch processing. */
292 gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)
294 /* Excess precision other than "fast" requires front-end
296 if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD
297 && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)
298 sorry ("-fexcess-precision=standard for Ada");
299 flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
301 /* ??? The warning machinery is outsmarted by Ada. */
302 warn_unused_parameter = 0;
304 /* No psABI change warnings for Ada. */
307 /* Force eliminate_unused_debug_types to 0 unless an explicit positive
308 -f has been passed. This forces the default to 0 for Ada, which might
309 differ from the common default. */
310 if (flag_eliminate_unused_debug_types < 0)
311 flag_eliminate_unused_debug_types = 1;
313 flag_eliminate_unused_debug_types = 0;
315 /* Reflect the explicit request of DWARF extensions into the common
316 flag for use by later passes. */
317 if (write_symbols == DWARF2_DEBUG)
318 use_gnu_debug_info_extensions = gnat_dwarf_extensions > 0;
323 /* Here is the function to handle the compiler error processing in GCC. */
326 internal_error_function (diagnostic_context *context,
327 const char *msgid, va_list *ap)
330 char *buffer, *p, *loc;
331 String_Template temp, temp_loc;
332 Fat_Pointer fp, fp_loc;
335 /* Warn if plugins present. */
338 /* Reset the pretty-printer. */
339 pp_clear_output_area (context->printer);
341 /* Format the message into the pretty-printer. */
342 tinfo.format_spec = msgid;
344 tinfo.err_no = errno;
345 pp_format_verbatim (context->printer, &tinfo);
347 /* Extract a (writable) pointer to the formatted text. */
348 buffer = xstrdup (pp_formatted_text (context->printer));
350 /* Go up to the first newline. */
351 for (p = buffer; *p; p++)
359 temp.High_Bound = p - buffer;
363 s = expand_location (input_location);
364 if (context->show_column && s.column != 0)
365 asprintf (&loc, "%s:%d:%d", s.file, s.line, s.column);
367 asprintf (&loc, "%s:%d", s.file, s.line);
368 temp_loc.Low_Bound = 1;
369 temp_loc.High_Bound = strlen (loc);
370 fp_loc.Bounds = &temp_loc;
373 Current_Error_Node = error_gnat_node;
374 Compiler_Abort (fp, -1, fp_loc);
377 /* Perform all the initialization steps that are language-specific. */
382 /* Do little here, most of the standard declarations are set up after the
383 front-end has been run. Use the same `char' as C, this doesn't really
384 matter since we'll use the explicit `unsigned char' for Character. */
385 build_common_tree_nodes (flag_signed_char);
387 /* In Ada, we use the unsigned type corresponding to the width of Pmode as
388 SIZETYPE. In most cases when ptr_mode and Pmode differ, C will use the
389 width of ptr_mode for SIZETYPE, but we get better code using the width
390 of Pmode. Note that, although we manipulate negative offsets for some
391 internal constructs and rely on compile time overflow detection in size
392 computations, using unsigned types for SIZETYPEs is fine since they are
393 treated specially by the middle-end, in particular sign-extended. */
394 size_type_node = gnat_type_for_mode (Pmode, 1);
395 set_sizetype (size_type_node);
396 TYPE_NAME (sizetype) = get_identifier ("size_type");
398 /* In Ada, we use an unsigned 8-bit type for the default boolean type. */
399 boolean_type_node = make_unsigned_type (8);
400 TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
401 SET_TYPE_RM_MAX_VALUE (boolean_type_node,
402 build_int_cst (boolean_type_node, 1));
403 SET_TYPE_RM_SIZE (boolean_type_node, bitsize_int (1));
405 build_common_tree_nodes_2 (0);
406 sbitsize_one_node = sbitsize_int (1);
407 sbitsize_unit_node = sbitsize_int (BITS_PER_UNIT);
408 boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
410 ptr_void_type_node = build_pointer_type (void_type_node);
412 /* Show that REFERENCE_TYPEs are internal and should be Pmode. */
413 internal_reference_types ();
415 /* Register our internal error function. */
416 global_dc->internal_error = &internal_error_function;
421 /* If we are using the GCC mechanism to process exception handling, we
422 have to register the personality routine for Ada and to initialize
423 various language dependent hooks. */
426 gnat_init_gcc_eh (void)
428 #ifdef DWARF2_UNWIND_INFO
429 /* lang_dependent_init already called dwarf2out_frame_init if true. */
430 int dwarf2out_frame_initialized = dwarf2out_do_frame ();
433 /* We shouldn't do anything if the No_Exceptions_Handler pragma is set,
434 though. This could for instance lead to the emission of tables with
435 references to symbols (such as the Ada eh personality routine) within
436 libraries we won't link against. */
437 if (No_Exception_Handlers_Set ())
440 /* Tell GCC we are handling cleanup actions through exception propagation.
441 This opens possibilities that we don't take advantage of yet, but is
442 nonetheless necessary to ensure that fixup code gets assigned to the
443 right exception regions. */
444 using_eh_for_cleanups ();
446 /* Turn on -fexceptions and -fnon-call-exceptions. The first one triggers
447 the generation of the necessary exception tables. The second one is
448 useful for two reasons: 1/ we map some asynchronous signals like SEGV to
449 exceptions, so we need to ensure that the insns which can lead to such
450 signals are correctly attached to the exception region they pertain to,
451 2/ Some calls to pure subprograms are handled as libcall blocks and then
452 marked as "cannot trap" if the flag is not set (see emit_libcall_block).
453 We should not let this be since it is possible for such calls to actually
456 flag_non_call_exceptions = 1;
459 #ifdef DWARF2_UNWIND_INFO
460 if (!dwarf2out_frame_initialized && dwarf2out_do_frame ())
461 dwarf2out_frame_init ();
465 /* Print language-specific items in declaration NODE. */
468 gnat_print_decl (FILE *file, tree node, int indent)
470 switch (TREE_CODE (node))
473 print_node (file, "corresponding var",
474 DECL_CONST_CORRESPONDING_VAR (node), indent + 4);
478 print_node (file, "original field", DECL_ORIGINAL_FIELD (node),
483 print_node (file, "renamed object", DECL_RENAMED_OBJECT (node),
492 /* Print language-specific items in type NODE. */
495 gnat_print_type (FILE *file, tree node, int indent)
497 switch (TREE_CODE (node))
500 print_node (file, "ci/co list", TYPE_CI_CO_LIST (node), indent + 4);
504 if (TYPE_MODULAR_P (node))
505 print_node_brief (file, "modulus", TYPE_MODULUS (node), indent + 4);
506 else if (TYPE_HAS_ACTUAL_BOUNDS_P (node))
507 print_node (file, "actual bounds", TYPE_ACTUAL_BOUNDS (node),
509 else if (TYPE_VAX_FLOATING_POINT_P (node))
512 print_node (file, "index type", TYPE_INDEX_TYPE (node), indent + 4);
514 /* ... fall through ... */
518 print_node_brief (file, "RM size", TYPE_RM_SIZE (node), indent + 4);
520 /* ... fall through ... */
523 print_node_brief (file, "RM min", TYPE_RM_MIN_VALUE (node), indent + 4);
524 print_node_brief (file, "RM max", TYPE_RM_MAX_VALUE (node), indent + 4);
528 print_node (file,"actual bounds", TYPE_ACTUAL_BOUNDS (node), indent + 4);
532 print_node (file,"representative array",
533 TYPE_REPRESENTATIVE_ARRAY (node), indent + 4);
537 if (TYPE_FAT_POINTER_P (node) || TYPE_CONTAINS_TEMPLATE_P (node))
538 print_node (file, "unconstrained array",
539 TYPE_UNCONSTRAINED_ARRAY (node), indent + 4);
541 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
545 case QUAL_UNION_TYPE:
546 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
554 /* Return the name to be printed for DECL. */
557 gnat_printable_name (tree decl, int verbosity)
559 const char *coded_name = IDENTIFIER_POINTER (DECL_NAME (decl));
560 char *ada_name = (char *) ggc_alloc_atomic (strlen (coded_name) * 2 + 60);
562 __gnat_decode (coded_name, ada_name, 0);
564 if (verbosity == 2 && !DECL_IS_BUILTIN (decl))
566 Set_Identifier_Casing (ada_name, DECL_SOURCE_FILE (decl));
567 return ggc_strdup (Name_Buffer);
573 /* Return the name to be used in DWARF debug info for DECL. */
576 gnat_dwarf_name (tree decl, int verbosity ATTRIBUTE_UNUSED)
578 gcc_assert (DECL_P (decl));
579 return (const char *) IDENTIFIER_POINTER (DECL_NAME (decl));
582 /* Do nothing (return the tree node passed). */
585 gnat_return_tree (tree t)
590 /* Get the alias set corresponding to a type or expression. */
592 static alias_set_type
593 gnat_get_alias_set (tree type)
595 /* If this is a padding type, use the type of the first field. */
596 if (TYPE_IS_PADDING_P (type))
597 return get_alias_set (TREE_TYPE (TYPE_FIELDS (type)));
599 /* If the type is an unconstrained array, use the type of the
600 self-referential array we make. */
601 else if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
603 get_alias_set (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))));
605 /* If the type can alias any other types, return the alias set 0. */
606 else if (TYPE_P (type)
607 && TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (type)))
613 /* GNU_TYPE is a type. Return its maximum size in bytes, if known,
614 as a constant when possible. */
617 gnat_type_max_size (const_tree gnu_type)
619 /* First see what we can get from TYPE_SIZE_UNIT, which might not
620 be constant even for simple expressions if it has already been
621 elaborated and possibly replaced by a VAR_DECL. */
622 tree max_unitsize = max_size (TYPE_SIZE_UNIT (gnu_type), true);
624 /* If we don't have a constant, see what we can get from TYPE_ADA_SIZE,
625 which should stay untouched. */
626 if (!host_integerp (max_unitsize, 1)
627 && (TREE_CODE (gnu_type) == RECORD_TYPE
628 || TREE_CODE (gnu_type) == UNION_TYPE
629 || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
630 && TYPE_ADA_SIZE (gnu_type))
632 tree max_adasize = max_size (TYPE_ADA_SIZE (gnu_type), true);
634 /* If we have succeeded in finding a constant, round it up to the
635 type's alignment and return the result in units. */
636 if (host_integerp (max_adasize, 1))
638 = size_binop (CEIL_DIV_EXPR,
639 round_up (max_adasize, TYPE_ALIGN (gnu_type)),
646 /* GNU_TYPE is a subtype of an integral type. Set LOWVAL to the low bound
647 and HIGHVAL to the high bound, respectively. */
650 gnat_get_subrange_bounds (const_tree gnu_type, tree *lowval, tree *highval)
652 *lowval = TYPE_MIN_VALUE (gnu_type);
653 *highval = TYPE_MAX_VALUE (gnu_type);
656 /* GNU_TYPE is a type. Determine if it should be passed by reference by
660 default_pass_by_ref (tree gnu_type)
662 /* We pass aggregates by reference if they are sufficiently large. The
663 choice of constant here is somewhat arbitrary. We also pass by
664 reference if the target machine would either pass or return by
665 reference. Strictly speaking, we need only check the return if this
666 is an In Out parameter, but it's probably best to err on the side of
667 passing more things by reference. */
669 if (pass_by_reference (NULL, TYPE_MODE (gnu_type), gnu_type, 1))
672 if (targetm.calls.return_in_memory (gnu_type, NULL_TREE))
675 if (AGGREGATE_TYPE_P (gnu_type)
676 && (!host_integerp (TYPE_SIZE (gnu_type), 1)
677 || 0 < compare_tree_int (TYPE_SIZE (gnu_type),
678 8 * TYPE_ALIGN (gnu_type))))
684 /* GNU_TYPE is the type of a subprogram parameter. Determine from the type if
685 it should be passed by reference. */
688 must_pass_by_ref (tree gnu_type)
690 /* We pass only unconstrained objects, those required by the language
691 to be passed by reference, and objects of variable size. The latter
692 is more efficient, avoids problems with variable size temporaries,
693 and does not produce compatibility problems with C, since C does
694 not have such objects. */
695 return (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
696 || TREE_ADDRESSABLE (gnu_type)
697 || (TYPE_SIZE (gnu_type)
698 && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));
701 /* Return the size of the FP mode with precision PREC. */
704 fp_prec_to_size (int prec)
706 enum machine_mode mode;
708 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
709 mode = GET_MODE_WIDER_MODE (mode))
710 if (GET_MODE_PRECISION (mode) == prec)
711 return GET_MODE_BITSIZE (mode);
716 /* Return the precision of the FP mode with size SIZE. */
719 fp_size_to_prec (int size)
721 enum machine_mode mode;
723 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
724 mode = GET_MODE_WIDER_MODE (mode))
725 if (GET_MODE_BITSIZE (mode) == size)
726 return GET_MODE_PRECISION (mode);
731 static GTY(()) tree gnat_eh_personality_decl;
734 gnat_eh_personality (void)
736 if (!gnat_eh_personality_decl)
737 gnat_eh_personality_decl
738 = build_personality_function (USING_SJLJ_EXCEPTIONS
739 ? "__gnat_eh_personality_sj"
740 : "__gnat_eh_personality");
742 return gnat_eh_personality_decl;
745 #include "gt-ada-misc.h"