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. */
47 #include "except.h" /* For USING_SJLJ_EXCEPTIONS. */
50 #include "adadecode.h"
64 static bool gnat_init (void);
65 static unsigned int gnat_init_options (unsigned int, const char **);
66 static int gnat_handle_option (size_t, const char *, int, int);
67 static bool gnat_post_options (const char **);
68 static alias_set_type gnat_get_alias_set (tree);
69 static void gnat_print_decl (FILE *, tree, int);
70 static void gnat_print_type (FILE *, tree, int);
71 static const char *gnat_printable_name (tree, int);
72 static const char *gnat_dwarf_name (tree, int);
73 static tree gnat_return_tree (tree);
74 static void gnat_parse_file (int);
75 static void internal_error_function (diagnostic_context *,
76 const char *, va_list *);
77 static tree gnat_type_max_size (const_tree);
78 static void gnat_get_subrange_bounds (const_tree, tree *, tree *);
79 static tree gnat_eh_personality (void);
81 /* Definitions for our language-specific hooks. */
83 #undef LANG_HOOKS_NAME
84 #define LANG_HOOKS_NAME "GNU Ada"
85 #undef LANG_HOOKS_IDENTIFIER_SIZE
86 #define LANG_HOOKS_IDENTIFIER_SIZE sizeof (struct tree_identifier)
87 #undef LANG_HOOKS_INIT
88 #define LANG_HOOKS_INIT gnat_init
89 #undef LANG_HOOKS_INIT_OPTIONS
90 #define LANG_HOOKS_INIT_OPTIONS gnat_init_options
91 #undef LANG_HOOKS_HANDLE_OPTION
92 #define LANG_HOOKS_HANDLE_OPTION gnat_handle_option
93 #undef LANG_HOOKS_POST_OPTIONS
94 #define LANG_HOOKS_POST_OPTIONS gnat_post_options
95 #undef LANG_HOOKS_PARSE_FILE
96 #define LANG_HOOKS_PARSE_FILE gnat_parse_file
97 #undef LANG_HOOKS_HASH_TYPES
98 #define LANG_HOOKS_HASH_TYPES false
99 #undef LANG_HOOKS_GETDECLS
100 #define LANG_HOOKS_GETDECLS lhd_return_null_tree_v
101 #undef LANG_HOOKS_PUSHDECL
102 #define LANG_HOOKS_PUSHDECL gnat_return_tree
103 #undef LANG_HOOKS_WRITE_GLOBALS
104 #define LANG_HOOKS_WRITE_GLOBALS gnat_write_global_declarations
105 #undef LANG_HOOKS_GET_ALIAS_SET
106 #define LANG_HOOKS_GET_ALIAS_SET gnat_get_alias_set
107 #undef LANG_HOOKS_PRINT_DECL
108 #define LANG_HOOKS_PRINT_DECL gnat_print_decl
109 #undef LANG_HOOKS_PRINT_TYPE
110 #define LANG_HOOKS_PRINT_TYPE gnat_print_type
111 #undef LANG_HOOKS_TYPE_MAX_SIZE
112 #define LANG_HOOKS_TYPE_MAX_SIZE gnat_type_max_size
113 #undef LANG_HOOKS_DECL_PRINTABLE_NAME
114 #define LANG_HOOKS_DECL_PRINTABLE_NAME gnat_printable_name
115 #undef LANG_HOOKS_DWARF_NAME
116 #define LANG_HOOKS_DWARF_NAME gnat_dwarf_name
117 #undef LANG_HOOKS_GIMPLIFY_EXPR
118 #define LANG_HOOKS_GIMPLIFY_EXPR gnat_gimplify_expr
119 #undef LANG_HOOKS_TYPE_FOR_MODE
120 #define LANG_HOOKS_TYPE_FOR_MODE gnat_type_for_mode
121 #undef LANG_HOOKS_TYPE_FOR_SIZE
122 #define LANG_HOOKS_TYPE_FOR_SIZE gnat_type_for_size
123 #undef LANG_HOOKS_TYPES_COMPATIBLE_P
124 #define LANG_HOOKS_TYPES_COMPATIBLE_P gnat_types_compatible_p
125 #undef LANG_HOOKS_GET_SUBRANGE_BOUNDS
126 #define LANG_HOOKS_GET_SUBRANGE_BOUNDS gnat_get_subrange_bounds
127 #undef LANG_HOOKS_ATTRIBUTE_TABLE
128 #define LANG_HOOKS_ATTRIBUTE_TABLE gnat_internal_attribute_table
129 #undef LANG_HOOKS_BUILTIN_FUNCTION
130 #define LANG_HOOKS_BUILTIN_FUNCTION gnat_builtin_function
131 #undef LANG_HOOKS_EH_PERSONALITY
132 #define LANG_HOOKS_EH_PERSONALITY gnat_eh_personality
133 #undef LANG_HOOKS_DEEP_UNSHARING
134 #define LANG_HOOKS_DEEP_UNSHARING true
136 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
138 /* How much we want of our DWARF extensions. Some of our dwarf+ extensions
139 are incompatible with regular GDB versions, so we must make sure to only
140 produce them on explicit request. This is eventually reflected into the
141 use_gnu_debug_info_extensions common flag for later processing. */
142 static int gnat_dwarf_extensions = 0;
144 /* Command-line argc and argv. These variables are global
145 since they are imported in back_end.adb. */
146 unsigned int save_argc;
147 const char **save_argv;
149 /* GNAT argc and argv. */
150 extern int gnat_argc;
151 extern char **gnat_argv;
153 /* Declare functions we use as part of startup. */
154 extern void __gnat_initialize (void *);
155 extern void __gnat_install_SEH_handler (void *);
156 extern void adainit (void);
157 extern void _ada_gnat1drv (void);
159 /* The parser for the language. For us, we process the GNAT tree. */
162 gnat_parse_file (int set_yydebug ATTRIBUTE_UNUSED)
166 /* Call the target specific initializations. */
167 __gnat_initialize (NULL);
169 /* ??? Call the SEH initialization routine. This is to workaround
170 a bootstrap path problem. The call below should be removed at some
171 point and the SEH pointer passed to __gnat_initialize() above. */
172 __gnat_install_SEH_handler((void *)seh);
174 /* Call the front-end elaboration procedures. */
177 /* Call the front end. */
181 /* Decode all the language specific options that cannot be decoded by GCC.
182 The option decoding phase of GCC calls this routine on the flags that
183 it cannot decode. Return the number of consecutive arguments from ARGV
184 that have been successfully decoded or 0 on failure. */
187 gnat_handle_option (size_t scode, const char *arg, int value,
188 int kind ATTRIBUTE_UNUSED)
190 const struct cl_option *option = &cl_options[scode];
191 enum opt_code code = (enum opt_code) scode;
194 if (arg == NULL && (option->flags & (CL_JOINED | CL_SEPARATE)))
196 error ("missing argument to \"-%s\"", option->opt_text);
203 q = XNEWVEC (char, sizeof("-I") + strlen (arg));
206 gnat_argv[gnat_argc] = q;
212 warn_uninitialized = value;
215 /* These are used in the GCC Makefile. */
216 case OPT_Wmissing_prototypes:
217 case OPT_Wstrict_prototypes:
218 case OPT_Wwrite_strings:
220 case OPT_Wvariadic_macros:
221 case OPT_Wold_style_definition:
222 case OPT_Wmissing_format_attribute:
223 case OPT_Woverlength_strings:
226 /* This is handled by the front-end. */
231 gnat_argv[gnat_argc] = xstrdup ("-nostdlib");
235 case OPT_feliminate_unused_debug_types:
236 /* We arrange for post_option to be able to only set the corresponding
237 flag to 1 when explicitly requested by the user. We expect the
238 default flag value to be either 0 or positive, and expose a positive
239 -f as a negative value to post_option. */
240 flag_eliminate_unused_debug_types = -value;
244 gnat_argv[gnat_argc] = xstrdup ("-fRTS");
249 warning (0, "%<-gnat%> misspelled as %<-gant%>");
251 /* ... fall through ... */
254 /* Recopy the switches without the 'gnat' prefix. */
255 gnat_argv[gnat_argc] = XNEWVEC (char, strlen (arg) + 2);
256 gnat_argv[gnat_argc][0] = '-';
257 strcpy (gnat_argv[gnat_argc] + 1, arg);
262 gnat_argv[gnat_argc] = xstrdup ("-O");
264 gnat_argv[gnat_argc] = xstrdup (arg);
269 gnat_dwarf_extensions = 1;
279 /* Initialize for option processing. */
282 gnat_init_options (unsigned int argc, const char **argv)
284 /* Initialize gnat_argv with save_argv size. */
285 gnat_argv = (char **) xmalloc ((argc + 1) * sizeof (argv[0]));
286 gnat_argv[0] = xstrdup (argv[0]); /* name of the command */
292 /* Uninitialized really means uninitialized in Ada. */
293 flag_zero_initialized_in_bss = 0;
298 /* Post-switch processing. */
301 gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)
303 /* Excess precision other than "fast" requires front-end
305 if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD
306 && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)
307 sorry ("-fexcess-precision=standard for Ada");
308 flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
310 /* ??? The warning machinery is outsmarted by Ada. */
311 warn_unused_parameter = 0;
313 /* No psABI change warnings for Ada. */
316 /* Force eliminate_unused_debug_types to 0 unless an explicit positive
317 -f has been passed. This forces the default to 0 for Ada, which might
318 differ from the common default. */
319 if (flag_eliminate_unused_debug_types < 0)
320 flag_eliminate_unused_debug_types = 1;
322 flag_eliminate_unused_debug_types = 0;
324 /* Reflect the explicit request of DWARF extensions into the common
325 flag for use by later passes. */
326 if (write_symbols == DWARF2_DEBUG)
327 use_gnu_debug_info_extensions = gnat_dwarf_extensions > 0;
332 /* Here is the function to handle the compiler error processing in GCC. */
335 internal_error_function (diagnostic_context *context,
336 const char *msgid, va_list *ap)
339 char *buffer, *p, *loc;
340 String_Template temp, temp_loc;
341 Fat_Pointer fp, fp_loc;
344 /* Warn if plugins present. */
347 /* Reset the pretty-printer. */
348 pp_clear_output_area (context->printer);
350 /* Format the message into the pretty-printer. */
351 tinfo.format_spec = msgid;
353 tinfo.err_no = errno;
354 pp_format_verbatim (context->printer, &tinfo);
356 /* Extract a (writable) pointer to the formatted text. */
357 buffer = xstrdup (pp_formatted_text (context->printer));
359 /* Go up to the first newline. */
360 for (p = buffer; *p; p++)
368 temp.High_Bound = p - buffer;
372 s = expand_location (input_location);
373 if (context->show_column && s.column != 0)
374 asprintf (&loc, "%s:%d:%d", s.file, s.line, s.column);
376 asprintf (&loc, "%s:%d", s.file, s.line);
377 temp_loc.Low_Bound = 1;
378 temp_loc.High_Bound = strlen (loc);
379 fp_loc.Bounds = &temp_loc;
382 Current_Error_Node = error_gnat_node;
383 Compiler_Abort (fp, -1, fp_loc);
386 /* Perform all the initialization steps that are language-specific. */
391 /* Do little here, most of the standard declarations are set up after the
392 front-end has been run. Use the same `char' as C, this doesn't really
393 matter since we'll use the explicit `unsigned char' for Character. */
394 build_common_tree_nodes (flag_signed_char);
396 /* In Ada, we use the unsigned type corresponding to the width of Pmode as
397 SIZETYPE. In most cases when ptr_mode and Pmode differ, C will use the
398 width of ptr_mode for SIZETYPE, but we get better code using the width
399 of Pmode. Note that, although we manipulate negative offsets for some
400 internal constructs and rely on compile time overflow detection in size
401 computations, using unsigned types for SIZETYPEs is fine since they are
402 treated specially by the middle-end, in particular sign-extended. */
403 size_type_node = gnat_type_for_mode (Pmode, 1);
404 set_sizetype (size_type_node);
405 TYPE_NAME (sizetype) = get_identifier ("size_type");
407 /* In Ada, we use an unsigned 8-bit type for the default boolean type. */
408 boolean_type_node = make_unsigned_type (8);
409 TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
410 SET_TYPE_RM_MAX_VALUE (boolean_type_node,
411 build_int_cst (boolean_type_node, 1));
412 SET_TYPE_RM_SIZE (boolean_type_node, bitsize_int (1));
414 build_common_tree_nodes_2 (0);
415 sbitsize_one_node = sbitsize_int (1);
416 sbitsize_unit_node = sbitsize_int (BITS_PER_UNIT);
417 boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
419 ptr_void_type_node = build_pointer_type (void_type_node);
421 /* Show that REFERENCE_TYPEs are internal and should be Pmode. */
422 internal_reference_types ();
424 /* Add the input filename as the last argument. */
425 if (main_input_filename)
427 gnat_argv[gnat_argc] = xstrdup (main_input_filename);
429 gnat_argv[gnat_argc] = NULL;
432 /* Register our internal error function. */
433 global_dc->internal_error = &internal_error_function;
438 /* If we are using the GCC mechanism to process exception handling, we
439 have to register the personality routine for Ada and to initialize
440 various language dependent hooks. */
443 gnat_init_gcc_eh (void)
445 #ifdef DWARF2_UNWIND_INFO
446 /* lang_dependent_init already called dwarf2out_frame_init if true. */
447 int dwarf2out_frame_initialized = dwarf2out_do_frame ();
450 /* We shouldn't do anything if the No_Exceptions_Handler pragma is set,
451 though. This could for instance lead to the emission of tables with
452 references to symbols (such as the Ada eh personality routine) within
453 libraries we won't link against. */
454 if (No_Exception_Handlers_Set ())
457 /* Tell GCC we are handling cleanup actions through exception propagation.
458 This opens possibilities that we don't take advantage of yet, but is
459 nonetheless necessary to ensure that fixup code gets assigned to the
460 right exception regions. */
461 using_eh_for_cleanups ();
463 /* Turn on -fexceptions and -fnon-call-exceptions. The first one triggers
464 the generation of the necessary exception tables. The second one is
465 useful for two reasons: 1/ we map some asynchronous signals like SEGV to
466 exceptions, so we need to ensure that the insns which can lead to such
467 signals are correctly attached to the exception region they pertain to,
468 2/ Some calls to pure subprograms are handled as libcall blocks and then
469 marked as "cannot trap" if the flag is not set (see emit_libcall_block).
470 We should not let this be since it is possible for such calls to actually
473 flag_non_call_exceptions = 1;
476 #ifdef DWARF2_UNWIND_INFO
477 if (!dwarf2out_frame_initialized && dwarf2out_do_frame ())
478 dwarf2out_frame_init ();
482 /* Print language-specific items in declaration NODE. */
485 gnat_print_decl (FILE *file, tree node, int indent)
487 switch (TREE_CODE (node))
490 print_node (file, "corresponding var",
491 DECL_CONST_CORRESPONDING_VAR (node), indent + 4);
495 print_node (file, "original field", DECL_ORIGINAL_FIELD (node),
500 print_node (file, "renamed object", DECL_RENAMED_OBJECT (node),
509 /* Print language-specific items in type NODE. */
512 gnat_print_type (FILE *file, tree node, int indent)
514 switch (TREE_CODE (node))
517 print_node (file, "ci/co list", TYPE_CI_CO_LIST (node), indent + 4);
521 if (TYPE_MODULAR_P (node))
522 print_node_brief (file, "modulus", TYPE_MODULUS (node), indent + 4);
523 else if (TYPE_HAS_ACTUAL_BOUNDS_P (node))
524 print_node (file, "actual bounds", TYPE_ACTUAL_BOUNDS (node),
526 else if (TYPE_VAX_FLOATING_POINT_P (node))
529 print_node (file, "index type", TYPE_INDEX_TYPE (node), indent + 4);
531 /* ... fall through ... */
535 print_node_brief (file, "RM size", TYPE_RM_SIZE (node), indent + 4);
537 /* ... fall through ... */
540 print_node_brief (file, "RM min", TYPE_RM_MIN_VALUE (node), indent + 4);
541 print_node_brief (file, "RM max", TYPE_RM_MAX_VALUE (node), indent + 4);
545 print_node (file,"actual bounds", TYPE_ACTUAL_BOUNDS (node), indent + 4);
549 print_node (file,"representative array",
550 TYPE_REPRESENTATIVE_ARRAY (node), indent + 4);
554 if (TYPE_FAT_POINTER_P (node) || TYPE_CONTAINS_TEMPLATE_P (node))
555 print_node (file, "unconstrained array",
556 TYPE_UNCONSTRAINED_ARRAY (node), indent + 4);
558 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
562 case QUAL_UNION_TYPE:
563 print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
571 /* Return the name to be printed for DECL. */
574 gnat_printable_name (tree decl, int verbosity)
576 const char *coded_name = IDENTIFIER_POINTER (DECL_NAME (decl));
577 char *ada_name = (char *) ggc_alloc (strlen (coded_name) * 2 + 60);
579 __gnat_decode (coded_name, ada_name, 0);
581 if (verbosity == 2 && !DECL_IS_BUILTIN (decl))
583 Set_Identifier_Casing (ada_name, DECL_SOURCE_FILE (decl));
584 return ggc_strdup (Name_Buffer);
590 /* Return the name to be used in DWARF debug info for DECL. */
593 gnat_dwarf_name (tree decl, int verbosity ATTRIBUTE_UNUSED)
595 gcc_assert (DECL_P (decl));
596 return (const char *) IDENTIFIER_POINTER (DECL_NAME (decl));
599 /* Do nothing (return the tree node passed). */
602 gnat_return_tree (tree t)
607 /* Get the alias set corresponding to a type or expression. */
609 static alias_set_type
610 gnat_get_alias_set (tree type)
612 /* If this is a padding type, use the type of the first field. */
613 if (TYPE_IS_PADDING_P (type))
614 return get_alias_set (TREE_TYPE (TYPE_FIELDS (type)));
616 /* If the type is an unconstrained array, use the type of the
617 self-referential array we make. */
618 else if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
620 get_alias_set (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))));
622 /* If the type can alias any other types, return the alias set 0. */
623 else if (TYPE_P (type)
624 && TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (type)))
630 /* GNU_TYPE is a type. Return its maximum size in bytes, if known,
631 as a constant when possible. */
634 gnat_type_max_size (const_tree gnu_type)
636 /* First see what we can get from TYPE_SIZE_UNIT, which might not
637 be constant even for simple expressions if it has already been
638 elaborated and possibly replaced by a VAR_DECL. */
639 tree max_unitsize = max_size (TYPE_SIZE_UNIT (gnu_type), true);
641 /* If we don't have a constant, see what we can get from TYPE_ADA_SIZE,
642 which should stay untouched. */
643 if (!host_integerp (max_unitsize, 1)
644 && (TREE_CODE (gnu_type) == RECORD_TYPE
645 || TREE_CODE (gnu_type) == UNION_TYPE
646 || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
647 && TYPE_ADA_SIZE (gnu_type))
649 tree max_adasize = max_size (TYPE_ADA_SIZE (gnu_type), true);
651 /* If we have succeeded in finding a constant, round it up to the
652 type's alignment and return the result in units. */
653 if (host_integerp (max_adasize, 1))
655 = size_binop (CEIL_DIV_EXPR,
656 round_up (max_adasize, TYPE_ALIGN (gnu_type)),
663 /* GNU_TYPE is a subtype of an integral type. Set LOWVAL to the low bound
664 and HIGHVAL to the high bound, respectively. */
667 gnat_get_subrange_bounds (const_tree gnu_type, tree *lowval, tree *highval)
669 *lowval = TYPE_MIN_VALUE (gnu_type);
670 *highval = TYPE_MAX_VALUE (gnu_type);
673 /* GNU_TYPE is a type. Determine if it should be passed by reference by
677 default_pass_by_ref (tree gnu_type)
679 /* We pass aggregates by reference if they are sufficiently large. The
680 choice of constant here is somewhat arbitrary. We also pass by
681 reference if the target machine would either pass or return by
682 reference. Strictly speaking, we need only check the return if this
683 is an In Out parameter, but it's probably best to err on the side of
684 passing more things by reference. */
686 if (pass_by_reference (NULL, TYPE_MODE (gnu_type), gnu_type, 1))
689 if (targetm.calls.return_in_memory (gnu_type, NULL_TREE))
692 if (AGGREGATE_TYPE_P (gnu_type)
693 && (!host_integerp (TYPE_SIZE (gnu_type), 1)
694 || 0 < compare_tree_int (TYPE_SIZE (gnu_type),
695 8 * TYPE_ALIGN (gnu_type))))
701 /* GNU_TYPE is the type of a subprogram parameter. Determine from the type if
702 it should be passed by reference. */
705 must_pass_by_ref (tree gnu_type)
707 /* We pass only unconstrained objects, those required by the language
708 to be passed by reference, and objects of variable size. The latter
709 is more efficient, avoids problems with variable size temporaries,
710 and does not produce compatibility problems with C, since C does
711 not have such objects. */
712 return (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
713 || TREE_ADDRESSABLE (gnu_type)
714 || (TYPE_SIZE (gnu_type)
715 && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));
718 /* Return the size of the FP mode with precision PREC. */
721 fp_prec_to_size (int prec)
723 enum machine_mode mode;
725 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
726 mode = GET_MODE_WIDER_MODE (mode))
727 if (GET_MODE_PRECISION (mode) == prec)
728 return GET_MODE_BITSIZE (mode);
733 /* Return the precision of the FP mode with size SIZE. */
736 fp_size_to_prec (int size)
738 enum machine_mode mode;
740 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
741 mode = GET_MODE_WIDER_MODE (mode))
742 if (GET_MODE_BITSIZE (mode) == size)
743 return GET_MODE_PRECISION (mode);
748 static GTY(()) tree gnat_eh_personality_decl;
751 gnat_eh_personality (void)
753 if (!gnat_eh_personality_decl)
754 gnat_eh_personality_decl
755 = build_personality_function (USING_SJLJ_EXCEPTIONS
756 ? "__gnat_eh_personality_sj"
757 : "__gnat_eh_personality");
759 return gnat_eh_personality_decl;
762 #include "gt-ada-misc.h"