gcc/ada/gcc-interface/misc.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                                 M I S C                                  *
   6  *                                                                          *
   7  *                           C Implementation File                          *
   8  *                                                                          *
   9  *          Copyright (C) 1992-2009, 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 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/>.                                          *
  20  *                                                                          *
  21  * GNAT was originally developed  by the GNAT team at  New York University. *
  22  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  23  *                                                                          *
  24  ****************************************************************************/
  25
  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
  28    about RTL.  */
  29
  30 #include "config.h"
  31 #include "system.h"
  32 #include "coretypes.h"
  33 #include "tm.h"
  34 #include "tree.h"
  35 #include "real.h"
  36 #include "rtl.h"
  37 #include "diagnostic.h"
  38 #include "expr.h"
  39 #include "libfuncs.h"
  40 #include "ggc.h"
  41 #include "flags.h"
  42 #include "debug.h"
  43 #include "cgraph.h"
  44 #include "tree-inline.h"
  45 #include "insn-codes.h"
  46 #include "insn-flags.h"
  47 #include "insn-config.h"
  48 #include "optabs.h"
  49 #include "recog.h"
  50 #include "toplev.h"
  51 #include "output.h"
  52 #include "except.h"
  53 #include "tm_p.h"
  54 #include "langhooks.h"
  55 #include "langhooks-def.h"
  56 #include "target.h"
  57
  58 #include "ada.h"
  59 #include "types.h"
  60 #include "atree.h"
  61 #include "elists.h"
  62 #include "namet.h"
  63 #include "nlists.h"
  64 #include "stringt.h"
  65 #include "uintp.h"
  66 #include "fe.h"
  67 #include "sinfo.h"
  68 #include "einfo.h"
  69 #include "ada-tree.h"
  70 #include "gigi.h"
  71 #include "adadecode.h"
  72 #include "opts.h"
  73 #include "options.h"
  74
  75 extern FILE *asm_out_file;
  76
  77 /* The largest alignment, in bits, that is needed for using the widest
  78    move instruction.  */
  79 unsigned int largest_move_alignment;
  80
  81 static bool gnat_init                   (void);
  82 static void gnat_finish_incomplete_decl (tree);
  83 static unsigned int gnat_init_options   (unsigned int, const char **);
  84 static int gnat_handle_option           (size_t, const char *, int);
  85 static bool gnat_post_options           (const char **);
  86 static alias_set_type gnat_get_alias_set (tree);
  87 static void gnat_print_decl             (FILE *, tree, int);
  88 static void gnat_print_type             (FILE *, tree, int);
  89 static const char *gnat_printable_name  (tree, int);
  90 static const char *gnat_dwarf_name      (tree, int);
  91 static tree gnat_return_tree            (tree);
  92 static int gnat_eh_type_covers          (tree, tree);
  93 static void gnat_parse_file             (int);
  94 static void internal_error_function     (const char *, va_list *);
  95 static tree gnat_type_max_size          (const_tree);
  96
  97 /* Definitions for our language-specific hooks.  */
  98
  99 #undef  LANG_HOOKS_NAME
 100 #define LANG_HOOKS_NAME                 "GNU Ada"
 101 #undef  LANG_HOOKS_IDENTIFIER_SIZE
 102 #define LANG_HOOKS_IDENTIFIER_SIZE      sizeof (struct tree_identifier)
 103 #undef  LANG_HOOKS_INIT
 104 #define LANG_HOOKS_INIT                 gnat_init
 105 #undef  LANG_HOOKS_INIT_OPTIONS
 106 #define LANG_HOOKS_INIT_OPTIONS         gnat_init_options
 107 #undef  LANG_HOOKS_HANDLE_OPTION
 108 #define LANG_HOOKS_HANDLE_OPTION        gnat_handle_option
 109 #undef  LANG_HOOKS_POST_OPTIONS
 110 #define LANG_HOOKS_POST_OPTIONS         gnat_post_options
 111 #undef  LANG_HOOKS_PARSE_FILE
 112 #define LANG_HOOKS_PARSE_FILE           gnat_parse_file
 113 #undef  LANG_HOOKS_HASH_TYPES
 114 #define LANG_HOOKS_HASH_TYPES           false
 115 #undef  LANG_HOOKS_GETDECLS
 116 #define LANG_HOOKS_GETDECLS             lhd_return_null_tree_v
 117 #undef  LANG_HOOKS_PUSHDECL
 118 #define LANG_HOOKS_PUSHDECL             gnat_return_tree
 119 #undef  LANG_HOOKS_WRITE_GLOBALS
 120 #define LANG_HOOKS_WRITE_GLOBALS        gnat_write_global_declarations
 121 #undef  LANG_HOOKS_FINISH_INCOMPLETE_DECL
 122 #define LANG_HOOKS_FINISH_INCOMPLETE_DECL gnat_finish_incomplete_decl
 123 #undef  LANG_HOOKS_GET_ALIAS_SET
 124 #define LANG_HOOKS_GET_ALIAS_SET        gnat_get_alias_set
 125 #undef  LANG_HOOKS_MARK_ADDRESSABLE
 126 #define LANG_HOOKS_MARK_ADDRESSABLE     gnat_mark_addressable
 127 #undef  LANG_HOOKS_PRINT_DECL
 128 #define LANG_HOOKS_PRINT_DECL           gnat_print_decl
 129 #undef  LANG_HOOKS_PRINT_TYPE
 130 #define LANG_HOOKS_PRINT_TYPE           gnat_print_type
 131 #undef  LANG_HOOKS_TYPE_MAX_SIZE
 132 #define LANG_HOOKS_TYPE_MAX_SIZE        gnat_type_max_size
 133 #undef  LANG_HOOKS_DECL_PRINTABLE_NAME
 134 #define LANG_HOOKS_DECL_PRINTABLE_NAME  gnat_printable_name
 135 #undef  LANG_HOOKS_DWARF_NAME
 136 #define LANG_HOOKS_DWARF_NAME           gnat_dwarf_name
 137 #undef  LANG_HOOKS_GIMPLIFY_EXPR
 138 #define LANG_HOOKS_GIMPLIFY_EXPR        gnat_gimplify_expr
 139 #undef  LANG_HOOKS_TYPE_FOR_MODE
 140 #define LANG_HOOKS_TYPE_FOR_MODE        gnat_type_for_mode
 141 #undef  LANG_HOOKS_TYPE_FOR_SIZE
 142 #define LANG_HOOKS_TYPE_FOR_SIZE        gnat_type_for_size
 143 #undef  LANG_HOOKS_TYPES_COMPATIBLE_P
 144 #define LANG_HOOKS_TYPES_COMPATIBLE_P   gnat_types_compatible_p
 145 #undef  LANG_HOOKS_ATTRIBUTE_TABLE
 146 #define LANG_HOOKS_ATTRIBUTE_TABLE      gnat_internal_attribute_table
 147 #undef  LANG_HOOKS_BUILTIN_FUNCTION
 148 #define LANG_HOOKS_BUILTIN_FUNCTION        gnat_builtin_function
 149
 150 const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 151
 152 /* How much we want of our DWARF extensions.  Some of our dwarf+ extensions
 153    are incompatible with regular GDB versions, so we must make sure to only
 154    produce them on explicit request.  This is eventually reflected into the
 155    use_gnu_debug_info_extensions common flag for later processing.  */
 156
 157 static int gnat_dwarf_extensions = 0;
 158
 159 /* Command-line argc and argv.
 160    These variables are global, since they are imported and used in
 161    back_end.adb  */
 162
 163 unsigned int save_argc;
 164 const char **save_argv;
 165
 166 /* gnat standard argc argv */
 167
 168 extern int gnat_argc;
 169 extern char **gnat_argv;
 170
 171 \f
 172 /* Declare functions we use as part of startup.  */
 173 extern void __gnat_initialize           (void *);
 174 extern void __gnat_install_SEH_handler  (void *);
 175 extern void adainit                     (void);
 176 extern void _ada_gnat1drv               (void);
 177
 178 /* The parser for the language.  For us, we process the GNAT tree.  */
 179
 180 static void
 181 gnat_parse_file (int set_yydebug ATTRIBUTE_UNUSED)
 182 {
 183   int seh[2];
 184
 185   /* Call the target specific initializations.  */
 186   __gnat_initialize (NULL);
 187
 188   /* ??? Call the SEH initialization routine.  This is to workaround
 189   a bootstrap path problem.  The call below should be removed at some
 190   point and the SEH pointer passed to __gnat_initialize() above.  */
 191   __gnat_install_SEH_handler((void *)seh);
 192
 193   /* Call the front-end elaboration procedures.  */
 194   adainit ();
 195
 196   /* Call the front end.  */
 197   _ada_gnat1drv ();
 198
 199   /* We always have a single compilation unit in Ada.  */
 200   cgraph_finalize_compilation_unit ();
 201 }
 202
 203 /* Decode all the language specific options that cannot be decoded by GCC.
 204    The option decoding phase of GCC calls this routine on the flags that
 205    it cannot decode.  This routine returns the number of consecutive arguments
 206    from ARGV that it successfully decoded; 0 indicates failure.  */
 207
 208 static int
 209 gnat_handle_option (size_t scode, const char *arg, int value)
 210 {
 211   const struct cl_option *option = &cl_options[scode];
 212   enum opt_code code = (enum opt_code) scode;
 213   char *q;
 214
 215   if (arg == NULL && (option->flags & (CL_JOINED | CL_SEPARATE)))
 216     {
 217       error ("missing argument to \"-%s\"", option->opt_text);
 218       return 1;
 219     }
 220
 221   switch (code)
 222     {
 223     case OPT_I:
 224       q = XNEWVEC (char, sizeof("-I") + strlen (arg));
 225       strcpy (q, "-I");
 226       strcat (q, arg);
 227       gnat_argv[gnat_argc] = q;
 228       gnat_argc++;
 229       break;
 230
 231     case OPT_Wall:
 232       warn_unused = value;
 233
 234       /* We save the value of warn_uninitialized, since if they put
 235          -Wuninitialized on the command line, we need to generate a
 236          warning about not using it without also specifying -O.  */
 237       if (warn_uninitialized != 1)
 238         warn_uninitialized = (value ? 2 : 0);
 239       break;
 240
 241       /* These are used in the GCC Makefile.  */
 242     case OPT_Wmissing_prototypes:
 243     case OPT_Wstrict_prototypes:
 244     case OPT_Wwrite_strings:
 245     case OPT_Wlong_long:
 246     case OPT_Wvariadic_macros:
 247     case OPT_Wold_style_definition:
 248     case OPT_Wmissing_format_attribute:
 249     case OPT_Woverlength_strings:
 250       break;
 251
 252       /* This is handled by the front-end.  */
 253     case OPT_nostdinc:
 254       break;
 255
 256     case OPT_nostdlib:
 257       gnat_argv[gnat_argc] = xstrdup ("-nostdlib");
 258       gnat_argc++;
 259       break;
 260
 261     case OPT_feliminate_unused_debug_types:
 262       /* We arrange for post_option to be able to only set the corresponding
 263          flag to 1 when explicitly requested by the user.  We expect the
 264          default flag value to be either 0 or positive, and expose a positive
 265          -f as a negative value to post_option.  */
 266       flag_eliminate_unused_debug_types = -value;
 267       break;
 268
 269     case OPT_fRTS_:
 270       gnat_argv[gnat_argc] = xstrdup ("-fRTS");
 271       gnat_argc++;
 272       break;
 273
 274     case OPT_gant:
 275       warning (0, "%<-gnat%> misspelled as %<-gant%>");
 276
 277       /* ... fall through ... */
 278
 279     case OPT_gnat:
 280       /* Recopy the switches without the 'gnat' prefix.  */
 281       gnat_argv[gnat_argc] = XNEWVEC (char, strlen (arg) + 2);
 282       gnat_argv[gnat_argc][0] = '-';
 283       strcpy (gnat_argv[gnat_argc] + 1, arg);
 284       gnat_argc++;
 285       break;
 286
 287     case OPT_gnatO:
 288       gnat_argv[gnat_argc] = xstrdup ("-O");
 289       gnat_argc++;
 290       gnat_argv[gnat_argc] = xstrdup (arg);
 291       gnat_argc++;
 292       break;
 293
 294     case OPT_gdwarf_:
 295       gnat_dwarf_extensions ++;
 296       break;
 297
 298     default:
 299       gcc_unreachable ();
 300     }
 301
 302   return 1;
 303 }
 304
 305 /* Initialize for option processing.  */
 306
 307 static unsigned int
 308 gnat_init_options (unsigned int argc, const char **argv)
 309 {
 310   /* Initialize gnat_argv with save_argv size.  */
 311   gnat_argv = (char **) xmalloc ((argc + 1) * sizeof (argv[0]));
 312   gnat_argv[0] = xstrdup (argv[0]);     /* name of the command */
 313   gnat_argc = 1;
 314
 315   save_argc = argc;
 316   save_argv = argv;
 317
 318   /* Uninitialized really means uninitialized in Ada.  */
 319   flag_zero_initialized_in_bss = 0;
 320
 321   return CL_Ada;
 322 }
 323
 324 /* Post-switch processing.  */
 325
 326 bool
 327 gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 328 {
 329   /* Excess precision other than "fast" requires front-end
 330      support.  */
 331   if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD
 332       && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)
 333     sorry ("-fexcess-precision=standard for Ada");
 334   flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;
 335
 336   /* ??? The warning machinery is outsmarted by Ada.  */
 337   warn_unused_parameter = 0;
 338
 339   /* No psABI change warnings for Ada.  */
 340   warn_psabi = 0;
 341
 342   /* Force eliminate_unused_debug_types to 0 unless an explicit positive
 343      -f has been passed.  This forces the default to 0 for Ada, which might
 344      differ from the common default.  */
 345   if (flag_eliminate_unused_debug_types < 0)
 346     flag_eliminate_unused_debug_types = 1;
 347   else
 348     flag_eliminate_unused_debug_types = 0;
 349
 350   /* Reflect the explicit request of DWARF extensions into the common
 351      flag for use by later passes.  */
 352   if (write_symbols == DWARF2_DEBUG)
 353     use_gnu_debug_info_extensions = gnat_dwarf_extensions > 0;
 354
 355   return false;
 356 }
 357
 358 /* Here is the function to handle the compiler error processing in GCC.  */
 359
 360 static void
 361 internal_error_function (const char *msgid, va_list *ap)
 362 {
 363   text_info tinfo;
 364   char *buffer, *p, *loc;
 365   String_Template temp, temp_loc;
 366   Fat_Pointer fp, fp_loc;
 367   expanded_location s;
 368
 369   /* Reset the pretty-printer.  */
 370   pp_clear_output_area (global_dc->printer);
 371
 372   /* Format the message into the pretty-printer.  */
 373   tinfo.format_spec = msgid;
 374   tinfo.args_ptr = ap;
 375   tinfo.err_no = errno;
 376   pp_format_verbatim (global_dc->printer, &tinfo);
 377
 378   /* Extract a (writable) pointer to the formatted text.  */
 379   buffer = (char*) pp_formatted_text (global_dc->printer);
 380
 381   /* Go up to the first newline.  */
 382   for (p = buffer; *p; p++)
 383     if (*p == '\n')
 384       {
 385         *p = '\0';
 386         break;
 387       }
 388
 389   temp.Low_Bound = 1;
 390   temp.High_Bound = p - buffer;
 391   fp.Bounds = &temp;
 392   fp.Array = buffer;
 393
 394   s = expand_location (input_location);
 395   if (flag_show_column && s.column != 0)
 396     asprintf (&loc, "%s:%d:%d", s.file, s.line, s.column);
 397   else
 398     asprintf (&loc, "%s:%d", s.file, s.line);
 399   temp_loc.Low_Bound = 1;
 400   temp_loc.High_Bound = strlen (loc);
 401   fp_loc.Bounds = &temp_loc;
 402   fp_loc.Array = loc;
 403
 404   Current_Error_Node = error_gnat_node;
 405   Compiler_Abort (fp, -1, fp_loc);
 406 }
 407
 408 /* Perform all the initialization steps that are language-specific.  */
 409
 410 static bool
 411 gnat_init (void)
 412 {
 413   /* Performs whatever initialization steps needed by the language-dependent
 414      lexical analyzer.  */
 415   gnat_init_decl_processing ();
 416
 417   /* Add the input filename as the last argument.  */
 418   gnat_argv[gnat_argc] = (char *) main_input_filename;
 419   gnat_argc++;
 420   gnat_argv[gnat_argc] = 0;
 421
 422   global_dc->internal_error = &internal_error_function;
 423
 424   /* Show that REFERENCE_TYPEs are internal and should be Pmode.  */
 425   internal_reference_types ();
 426
 427   return true;
 428 }
 429
 430 /* This function is called indirectly from toplev.c to handle incomplete
 431    declarations, i.e. VAR_DECL nodes whose DECL_SIZE is zero.  To be precise,
 432    compile_file in toplev.c makes an indirect call through the function pointer
 433    incomplete_decl_finalize_hook which is initialized to this routine in
 434    init_decl_processing.  */
 435
 436 static void
 437 gnat_finish_incomplete_decl (tree dont_care ATTRIBUTE_UNUSED)
 438 {
 439   gcc_unreachable ();
 440 }
 441 \f
 442 /* Compute the alignment of the largest mode that can be used for copying
 443    objects.  */
 444
 445 void
 446 gnat_compute_largest_alignment (void)
 447 {
 448   enum machine_mode mode;
 449
 450   for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
 451        mode = GET_MODE_WIDER_MODE (mode))
 452     if (optab_handler (mov_optab, mode)->insn_code != CODE_FOR_nothing)
 453       largest_move_alignment = MIN (BIGGEST_ALIGNMENT,
 454                                     MAX (largest_move_alignment,
 455                                          GET_MODE_ALIGNMENT (mode)));
 456 }
 457
 458 /* If we are using the GCC mechanism to process exception handling, we
 459    have to register the personality routine for Ada and to initialize
 460    various language dependent hooks.  */
 461
 462 void
 463 gnat_init_gcc_eh (void)
 464 {
 465 #ifdef DWARF2_UNWIND_INFO
 466   /* lang_dependent_init already called dwarf2out_frame_init if true.  */
 467   int dwarf2out_frame_initialized = dwarf2out_do_frame ();
 468 #endif
 469
 470   /* We shouldn't do anything if the No_Exceptions_Handler pragma is set,
 471      though. This could for instance lead to the emission of tables with
 472      references to symbols (such as the Ada eh personality routine) within
 473      libraries we won't link against.  */
 474   if (No_Exception_Handlers_Set ())
 475     return;
 476
 477   /* Tell GCC we are handling cleanup actions through exception propagation.
 478      This opens possibilities that we don't take advantage of yet, but is
 479      nonetheless necessary to ensure that fixup code gets assigned to the
 480      right exception regions.  */
 481   using_eh_for_cleanups ();
 482
 483   eh_personality_libfunc = init_one_libfunc (USING_SJLJ_EXCEPTIONS
 484                                              ? "__gnat_eh_personality_sj"
 485                                              : "__gnat_eh_personality");
 486   lang_eh_type_covers = gnat_eh_type_covers;
 487   lang_eh_runtime_type = gnat_return_tree;
 488   default_init_unwind_resume_libfunc ();
 489
 490   /* Turn on -fexceptions and -fnon-call-exceptions. The first one triggers
 491      the generation of the necessary exception runtime tables. The second one
 492      is useful for two reasons: 1/ we map some asynchronous signals like SEGV
 493      to exceptions, so we need to ensure that the insns which can lead to such
 494      signals are correctly attached to the exception region they pertain to,
 495      2/ Some calls to pure subprograms are handled as libcall blocks and then
 496      marked as "cannot trap" if the flag is not set (see emit_libcall_block).
 497      We should not let this be since it is possible for such calls to actually
 498      raise in Ada.  */
 499   flag_exceptions = 1;
 500   flag_non_call_exceptions = 1;
 501
 502   init_eh ();
 503 #ifdef DWARF2_UNWIND_INFO
 504   if (!dwarf2out_frame_initialized && dwarf2out_do_frame ())
 505     dwarf2out_frame_init ();
 506 #endif
 507 }
 508
 509 /* Language hooks, first one to print language-specific items in a DECL.  */
 510
 511 static void
 512 gnat_print_decl (FILE *file, tree node, int indent)
 513 {
 514   switch (TREE_CODE (node))
 515     {
 516     case CONST_DECL:
 517       print_node (file, "const_corresponding_var",
 518                   DECL_CONST_CORRESPONDING_VAR (node), indent + 4);
 519       break;
 520
 521     case FIELD_DECL:
 522       print_node (file, "original_field", DECL_ORIGINAL_FIELD (node),
 523                   indent + 4);
 524       break;
 525
 526     case VAR_DECL:
 527       print_node (file, "renamed_object", DECL_RENAMED_OBJECT (node),
 528                   indent + 4);
 529       break;
 530
 531     default:
 532       break;
 533     }
 534 }
 535
 536 static void
 537 gnat_print_type (FILE *file, tree node, int indent)
 538 {
 539   switch (TREE_CODE (node))
 540     {
 541     case FUNCTION_TYPE:
 542       print_node (file, "ci_co_list", TYPE_CI_CO_LIST (node), indent + 4);
 543       break;
 544
 545     case ENUMERAL_TYPE:
 546     case BOOLEAN_TYPE:
 547       print_node (file, "RM size", TYPE_RM_SIZE_NUM (node), indent + 4);
 548       break;
 549
 550     case INTEGER_TYPE:
 551       if (TYPE_MODULAR_P (node))
 552         print_node (file, "modulus", TYPE_MODULUS (node), indent + 4);
 553       else if (TYPE_HAS_ACTUAL_BOUNDS_P (node))
 554         print_node (file, "actual bounds", TYPE_ACTUAL_BOUNDS (node),
 555                     indent + 4);
 556       else if (TYPE_VAX_FLOATING_POINT_P (node))
 557         ;
 558       else
 559         print_node (file, "index type", TYPE_INDEX_TYPE (node), indent + 4);
 560
 561       print_node (file, "RM size", TYPE_RM_SIZE_NUM (node), indent + 4);
 562       break;
 563
 564     case ARRAY_TYPE:
 565       print_node (file,"actual bounds", TYPE_ACTUAL_BOUNDS (node), indent + 4);
 566       break;
 567
 568     case RECORD_TYPE:
 569       if (TYPE_IS_FAT_POINTER_P (node) || TYPE_CONTAINS_TEMPLATE_P (node))
 570         print_node (file, "unconstrained array",
 571                     TYPE_UNCONSTRAINED_ARRAY (node), indent + 4);
 572       else
 573         print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
 574       break;
 575
 576     case UNION_TYPE:
 577     case QUAL_UNION_TYPE:
 578       print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);
 579       break;
 580
 581     default:
 582       break;
 583     }
 584 }
 585
 586 static const char *
 587 gnat_dwarf_name (tree t, int verbosity ATTRIBUTE_UNUSED)
 588 {
 589   gcc_assert (DECL_P (t));
 590
 591   return (const char *) IDENTIFIER_POINTER (DECL_NAME (t));
 592 }
 593
 594 static const char *
 595 gnat_printable_name (tree decl, int verbosity)
 596 {
 597   const char *coded_name = IDENTIFIER_POINTER (DECL_NAME (decl));
 598   char *ada_name = (char *) ggc_alloc (strlen (coded_name) * 2 + 60);
 599
 600   __gnat_decode (coded_name, ada_name, 0);
 601
 602   if (verbosity == 2 && !DECL_IS_BUILTIN (decl))
 603     {
 604       Set_Identifier_Casing (ada_name, (char *) DECL_SOURCE_FILE (decl));
 605       return ggc_strdup (Name_Buffer);
 606     }
 607   else
 608     return ada_name;
 609 }
 610
 611 /* Do nothing (return the tree node passed).  */
 612
 613 static tree
 614 gnat_return_tree (tree t)
 615 {
 616   return t;
 617 }
 618
 619 /* Return true if type A catches type B. Callback for flow analysis from
 620    the exception handling part of the back-end.  */
 621
 622 static int
 623 gnat_eh_type_covers (tree a, tree b)
 624 {
 625   /* a catches b if they represent the same exception id or if a
 626      is an "others".
 627
 628      ??? integer_zero_node for "others" is hardwired in too many places
 629      currently.  */
 630   return (a == b || a == integer_zero_node);
 631 }
 632 \f
 633 /* Get the alias set corresponding to a type or expression.  */
 634
 635 static alias_set_type
 636 gnat_get_alias_set (tree type)
 637 {
 638   /* If this is a padding type, use the type of the first field.  */
 639   if (TREE_CODE (type) == RECORD_TYPE
 640       && TYPE_IS_PADDING_P (type))
 641     return get_alias_set (TREE_TYPE (TYPE_FIELDS (type)));
 642
 643   /* If the type is an unconstrained array, use the type of the
 644      self-referential array we make.  */
 645   else if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)
 646     return
 647       get_alias_set (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))));
 648
 649   /* If the type can alias any other types, return the alias set 0.  */
 650   else if (TYPE_P (type)
 651            && TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (type)))
 652     return 0;
 653
 654   return -1;
 655 }
 656
 657 /* GNU_TYPE is a type.  Return its maximum size in bytes, if known,
 658    as a constant when possible.  */
 659
 660 static tree
 661 gnat_type_max_size (const_tree gnu_type)
 662 {
 663   /* First see what we can get from TYPE_SIZE_UNIT, which might not
 664      be constant even for simple expressions if it has already been
 665      elaborated and possibly replaced by a VAR_DECL.  */
 666   tree max_unitsize = max_size (TYPE_SIZE_UNIT (gnu_type), true);
 667
 668   /* If we don't have a constant, see what we can get from TYPE_ADA_SIZE,
 669      which should stay untouched.  */
 670   if (!host_integerp (max_unitsize, 1)
 671       && (TREE_CODE (gnu_type) == RECORD_TYPE
 672           || TREE_CODE (gnu_type) == UNION_TYPE
 673           || TREE_CODE (gnu_type) == QUAL_UNION_TYPE)
 674       && TYPE_ADA_SIZE (gnu_type))
 675     {
 676       tree max_adasize = max_size (TYPE_ADA_SIZE (gnu_type), true);
 677
 678       /* If we have succeeded in finding a constant, round it up to the
 679          type's alignment and return the result in units.  */
 680       if (host_integerp (max_adasize, 1))
 681         max_unitsize
 682           = size_binop (CEIL_DIV_EXPR,
 683                         round_up (max_adasize, TYPE_ALIGN (gnu_type)),
 684                         bitsize_unit_node);
 685     }
 686
 687   return max_unitsize;
 688 }
 689
 690 /* GNU_TYPE is a type. Determine if it should be passed by reference by
 691    default.  */
 692
 693 bool
 694 default_pass_by_ref (tree gnu_type)
 695 {
 696   /* We pass aggregates by reference if they are sufficiently large.  The
 697      choice of constant here is somewhat arbitrary.  We also pass by
 698      reference if the target machine would either pass or return by
 699      reference.  Strictly speaking, we need only check the return if this
 700      is an In Out parameter, but it's probably best to err on the side of
 701      passing more things by reference.  */
 702
 703   if (pass_by_reference (NULL, TYPE_MODE (gnu_type), gnu_type, 1))
 704     return true;
 705
 706   if (targetm.calls.return_in_memory (gnu_type, NULL_TREE))
 707     return true;
 708
 709   if (AGGREGATE_TYPE_P (gnu_type)
 710       && (!host_integerp (TYPE_SIZE (gnu_type), 1)
 711           || 0 < compare_tree_int (TYPE_SIZE (gnu_type),
 712                                    8 * TYPE_ALIGN (gnu_type))))
 713     return true;
 714
 715   return false;
 716 }
 717
 718 /* GNU_TYPE is the type of a subprogram parameter.  Determine from the type if
 719    it should be passed by reference. */
 720
 721 bool
 722 must_pass_by_ref (tree gnu_type)
 723 {
 724   /* We pass only unconstrained objects, those required by the language
 725      to be passed by reference, and objects of variable size.  The latter
 726      is more efficient, avoids problems with variable size temporaries,
 727      and does not produce compatibility problems with C, since C does
 728      not have such objects.  */
 729   return (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE
 730           || (AGGREGATE_TYPE_P (gnu_type) && TYPE_BY_REFERENCE_P (gnu_type))
 731           || (TYPE_SIZE (gnu_type)
 732               && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));
 733 }
 734
 735 /* This function is called by the front end to enumerate all the supported
 736    modes for the machine.  We pass a function which is called back with
 737    the following integer parameters:
 738
 739    FLOAT_P      nonzero if this represents a floating-point mode
 740    COMPLEX_P    nonzero is this represents a complex mode
 741    COUNT        count of number of items, nonzero for vector mode
 742    PRECISION    number of bits in data representation
 743    MANTISSA     number of bits in mantissa, if FP and known, else zero.
 744    SIZE         number of bits used to store data
 745    ALIGN        number of bits to which mode is aligned.  */
 746
 747 void
 748 enumerate_modes (void (*f) (int, int, int, int, int, int, unsigned int))
 749 {
 750   enum machine_mode i;
 751
 752   for (i = 0; i < NUM_MACHINE_MODES; i++)
 753     {
 754       enum machine_mode j;
 755       bool float_p = 0;
 756       bool complex_p = 0;
 757       bool vector_p = 0;
 758       bool skip_p = 0;
 759       int mantissa = 0;
 760       enum machine_mode inner_mode = i;
 761
 762       switch (GET_MODE_CLASS (i))
 763         {
 764         case MODE_INT:
 765           break;
 766         case MODE_FLOAT:
 767           float_p = 1;
 768           break;
 769         case MODE_COMPLEX_INT:
 770           complex_p = 1;
 771           inner_mode = GET_MODE_INNER (i);
 772           break;
 773         case MODE_COMPLEX_FLOAT:
 774           float_p = 1;
 775           complex_p = 1;
 776           inner_mode = GET_MODE_INNER (i);
 777           break;
 778         case MODE_VECTOR_INT:
 779           vector_p = 1;
 780           inner_mode = GET_MODE_INNER (i);
 781           break;
 782         case MODE_VECTOR_FLOAT:
 783           float_p = 1;
 784           vector_p = 1;
 785           inner_mode = GET_MODE_INNER (i);
 786           break;
 787         default:
 788           skip_p = 1;
 789         }
 790
 791       /* Skip this mode if it's one the front end doesn't need to know about
 792          (e.g., the CC modes) or if there is no add insn for that mode (or
 793          any wider mode), meaning it is not supported by the hardware.  If
 794          this a complex or vector mode, we care about the inner mode.  */
 795       for (j = inner_mode; j != VOIDmode; j = GET_MODE_WIDER_MODE (j))
 796         if (optab_handler (add_optab, j)->insn_code != CODE_FOR_nothing)
 797           break;
 798
 799       if (float_p)
 800         {
 801           const struct real_format *fmt = REAL_MODE_FORMAT (inner_mode);
 802
 803           mantissa = fmt->p;
 804         }
 805
 806       if (!skip_p && j != VOIDmode)
 807         (*f) (float_p, complex_p, vector_p ? GET_MODE_NUNITS (i) : 0,
 808               GET_MODE_BITSIZE (i), mantissa,
 809               GET_MODE_SIZE (i) * BITS_PER_UNIT, GET_MODE_ALIGNMENT (i));
 810     }
 811 }
 812
 813 int
 814 fp_prec_to_size (int prec)
 815 {
 816   enum machine_mode mode;
 817
 818   for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
 819        mode = GET_MODE_WIDER_MODE (mode))
 820     if (GET_MODE_PRECISION (mode) == prec)
 821       return GET_MODE_BITSIZE (mode);
 822
 823   gcc_unreachable ();
 824 }
 825
 826 int
 827 fp_size_to_prec (int size)
 828 {
 829   enum machine_mode mode;
 830
 831   for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
 832        mode = GET_MODE_WIDER_MODE (mode))
 833     if (GET_MODE_BITSIZE (mode) == size)
 834       return GET_MODE_PRECISION (mode);
 835
 836   gcc_unreachable ();
 837 }