gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009, 2010 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "ansidecl.h"
  23 #include "coretypes.h"
  24 #include "opts.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "ggc.h"
  28 #include "toplev.h"
  29 #include "debug.h"
  30 #include "options.h"
  31 #include "flags.h"
  32 #include "convert.h"
  33 #include "diagnostic.h"
  34 #include "langhooks.h"
  35 #include "langhooks-def.h"
  36 #include "except.h"
  37 #include "target.h"
  38
  39 #include <mpfr.h>
  40
  41 #include "go-c.h"
  42
  43 /* Language-dependent contents of a type.  */
  44
  45 struct GTY(()) lang_type
  46 {
  47   char dummy;
  48 };
  49
  50 /* Language-dependent contents of a decl.  */
  51
  52 struct GTY(()) lang_decl
  53 {
  54   char dummy;
  55 };
  56
  57 /* Language-dependent contents of an identifier.  This must include a
  58    tree_identifier.  */
  59
  60 struct GTY(()) lang_identifier
  61 {
  62   struct tree_identifier common;
  63 };
  64
  65 /* The resulting tree type.  */
  66
  67 union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
  68            chain_next ("(union lang_tree_node *) TREE_CHAIN (&%h.generic)")))
  69 lang_tree_node
  70 {
  71   union tree_node GTY((tag ("0"),
  72                        desc ("tree_node_structure (&%h)"))) generic;
  73   struct lang_identifier GTY((tag ("1"))) identifier;
  74 };
  75
  76 /* We don't use language_function.  */
  77
  78 struct GTY(()) language_function
  79 {
  80   int dummy;
  81 };
  82
  83 /* Language hooks.  */
  84
  85 static bool
  86 go_langhook_init (void)
  87 {
  88   build_common_tree_nodes (false);
  89
  90   /* The sizetype may be "unsigned long" or "unsigned long long".  */
  91   if (TYPE_MODE (long_unsigned_type_node) == ptr_mode)
  92     size_type_node = long_unsigned_type_node;
  93   else if (TYPE_MODE (long_long_unsigned_type_node) == ptr_mode)
  94     size_type_node = long_long_unsigned_type_node;
  95   else
  96     size_type_node = long_unsigned_type_node;
  97   set_sizetype (size_type_node);
  98
  99   build_common_tree_nodes_2 (0);
 100
 101   /* We must create the gogo IR after calling build_common_tree_nodes
 102      (because Gogo::define_builtin_function_trees refers indirectly
 103      to, e.g., unsigned_char_type_node) but before calling
 104      build_common_builtin_nodes (because it calls, indirectly,
 105      go_type_for_size).  */
 106   go_create_gogo (INT_TYPE_SIZE, FLOAT_TYPE_SIZE, POINTER_SIZE);
 107
 108   build_common_builtin_nodes ();
 109
 110   /* I don't know why this is not done by any of the above.  */
 111   void_list_node = build_tree_list (NULL_TREE, void_type_node);
 112
 113   /* The default precision for floating point numbers.  This is used
 114      for floating point constants with abstract type.  This may
 115      eventually be controllable by a command line option.  */
 116   mpfr_set_default_prec (128);
 117
 118   /* Go uses exceptions.  */
 119   using_eh_for_cleanups ();
 120
 121   return true;
 122 }
 123
 124 /* The option mask.  */
 125
 126 static unsigned int
 127 go_langhook_option_lang_mask (void)
 128 {
 129   return CL_Go;
 130 }
 131
 132 /* Initialize the options structure.  */
 133
 134 static void
 135 go_langhook_init_options_struct (struct gcc_options *opts)
 136 {
 137   /* Go says that signed overflow is precisely defined.  */
 138   opts->x_flag_wrapv = 1;
 139
 140   /* We default to using strict aliasing, since Go pointers are safe.
 141      This is turned off for code that imports the "unsafe" package,
 142      because using unsafe.pointer violates C style aliasing
 143      requirements.  */
 144   opts->x_flag_strict_aliasing = 1;
 145
 146   /* Default to avoiding range issues for complex multiply and
 147      divide.  */
 148   opts->x_flag_complex_method = 2;
 149
 150   /* The builtin math functions should not set errno.  */
 151   opts->x_flag_errno_math = 0;
 152
 153   /* By default assume that floating point math does not trap.  */
 154   opts->x_flag_trapping_math = 0;
 155
 156   /* We turn on stack splitting if we can.  */
 157   if (targetm.supports_split_stack (false, opts))
 158     opts->x_flag_split_stack = 1;
 159
 160   /* Exceptions are used to handle recovering from panics.  */
 161   opts->x_flag_exceptions = 1;
 162   opts->x_flag_non_call_exceptions = 1;
 163 }
 164
 165 /* Infrastructure for a VEC of char * pointers.  */
 166
 167 typedef const char *go_char_p;
 168 DEF_VEC_P(go_char_p);
 169 DEF_VEC_ALLOC_P(go_char_p, heap);
 170
 171 /* The list of directories to search after all the Go specific
 172    directories have been searched.  */
 173
 174 static VEC(go_char_p, heap) *go_search_dirs;
 175
 176 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 177
 178 static bool
 179 go_langhook_handle_option (
 180     size_t scode,
 181     const char *arg,
 182     int value ATTRIBUTE_UNUSED,
 183     int kind ATTRIBUTE_UNUSED,
 184     location_t loc ATTRIBUTE_UNUSED,
 185     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 186 {
 187   enum opt_code code = (enum opt_code) scode;
 188   bool ret = true;
 189
 190   switch (code)
 191     {
 192     case OPT_I:
 193       go_add_search_path (arg);
 194       break;
 195
 196     case OPT_L:
 197       /* A -L option is assumed to come from the compiler driver.
 198          This is a system directory.  We search the following
 199          directories, if they exist, before this one:
 200            dir/go/VERSION
 201            dir/go/VERSION/MACHINE
 202          This is like include/c++.  */
 203       {
 204         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 205         size_t len;
 206         char *p;
 207         struct stat st;
 208
 209         len = strlen (arg);
 210         p = XALLOCAVEC (char,
 211                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 212                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 213         strcpy (p, arg);
 214         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 215           strcat (p, dir_separator_str);
 216         strcat (p, "go");
 217         strcat (p, dir_separator_str);
 218         strcat (p, DEFAULT_TARGET_VERSION);
 219         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 220           {
 221             go_add_search_path (p);
 222             strcat (p, dir_separator_str);
 223             strcat (p, DEFAULT_TARGET_MACHINE);
 224             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 225               go_add_search_path (p);
 226           }
 227
 228         /* Search ARG too, but only after we've searched to Go
 229            specific directories for all -L arguments.  */
 230         VEC_safe_push (go_char_p, heap, go_search_dirs, arg);
 231       }
 232       break;
 233
 234     case OPT_fgo_dump_:
 235       ret = go_enable_dump (arg) ? true : false;
 236       break;
 237
 238     case OPT_fgo_prefix_:
 239       go_set_prefix (arg);
 240       break;
 241
 242     default:
 243       /* Just return 1 to indicate that the option is valid.  */
 244       break;
 245     }
 246
 247   return ret;
 248 }
 249
 250 /* Run after parsing options.  */
 251
 252 static bool
 253 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 254 {
 255   unsigned int ix;
 256   const char *dir;
 257
 258   gcc_assert (num_in_fnames > 0);
 259
 260   FOR_EACH_VEC_ELT (go_char_p, go_search_dirs, ix, dir)
 261     go_add_search_path (dir);
 262   VEC_free (go_char_p, heap, go_search_dirs);
 263   go_search_dirs = NULL;
 264
 265   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 266     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 267
 268   /* Returning false means that the backend should be used.  */
 269   return false;
 270 }
 271
 272 static void
 273 go_langhook_parse_file (void)
 274 {
 275   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 276                         go_require_return_statement);
 277 }
 278
 279 static tree
 280 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 281 {
 282   return go_type_for_size (bits, unsignedp);
 283 }
 284
 285 static tree
 286 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 287 {
 288   /* Go has no vector types.  Build them here.  FIXME: It does not
 289      make sense for the middle-end to ask the frontend for a type
 290      which the frontend does not support.  However, at least for now
 291      it is required.  See PR 46805.  */
 292   if (VECTOR_MODE_P (mode))
 293     {
 294       tree inner;
 295
 296       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 297       if (inner != NULL_TREE)
 298         return build_vector_type_for_mode (inner, mode);
 299       return NULL_TREE;
 300     }
 301
 302   return go_type_for_mode (mode, unsignedp);
 303 }
 304
 305 /* Record a builtin function.  We just ignore builtin functions.  */
 306
 307 static tree
 308 go_langhook_builtin_function (tree decl)
 309 {
 310   return decl;
 311 }
 312
 313 static int
 314 go_langhook_global_bindings_p (void)
 315 {
 316   return current_function_decl == NULL ? 1 : 0;
 317 }
 318
 319 /* Push a declaration into the current binding level.  We can't
 320    usefully implement this since we don't want to convert from tree
 321    back to one of our internal data structures.  I think the only way
 322    this is used is to record a decl which is to be returned by
 323    getdecls, and we could implement it for that purpose if
 324    necessary.  */
 325
 326 static tree
 327 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 328 {
 329   gcc_unreachable ();
 330 }
 331
 332 /* This hook is used to get the current list of declarations as trees.
 333    We don't support that; instead we use the write_globals hook.  This
 334    can't simply crash because it is called by -gstabs.  */
 335
 336 static tree
 337 go_langhook_getdecls (void)
 338 {
 339   return NULL;
 340 }
 341
 342 /* Write out globals.  */
 343
 344 static void
 345 go_langhook_write_globals (void)
 346 {
 347   go_write_globals ();
 348 }
 349
 350 /* Go specific gimplification.  We need to gimplify
 351    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 352    it.  */
 353
 354 static int
 355 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 356 {
 357   if (TREE_CODE (*expr_p) == CALL_EXPR
 358       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 359     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 360                    is_gimple_val, fb_rvalue);
 361   return GS_UNHANDLED;
 362 }
 363
 364 /* Return a decl for the exception personality function.  The function
 365    itself is implemented in libgo/runtime/go-unwind.c.  */
 366
 367 static tree
 368 go_langhook_eh_personality (void)
 369 {
 370   static tree personality_decl;
 371   if (personality_decl == NULL_TREE)
 372     {
 373       personality_decl = build_personality_function ("gccgo");
 374       go_preserve_from_gc (personality_decl);
 375     }
 376   return personality_decl;
 377 }
 378
 379 /* Functions called directly by the generic backend.  */
 380
 381 tree
 382 convert (tree type, tree expr)
 383 {
 384   if (type == error_mark_node
 385       || expr == error_mark_node
 386       || TREE_TYPE (expr) == error_mark_node)
 387     return error_mark_node;
 388
 389   if (type == TREE_TYPE (expr))
 390     return expr;
 391
 392   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 393     return fold_convert (type, expr);
 394
 395   switch (TREE_CODE (type))
 396     {
 397     case VOID_TYPE:
 398     case BOOLEAN_TYPE:
 399       return fold_convert (type, expr);
 400     case INTEGER_TYPE:
 401       return fold (convert_to_integer (type, expr));
 402     case POINTER_TYPE:
 403       return fold (convert_to_pointer (type, expr));
 404     case REAL_TYPE:
 405       return fold (convert_to_real (type, expr));
 406     case COMPLEX_TYPE:
 407       return fold (convert_to_complex (type, expr));
 408     default:
 409       break;
 410     }
 411
 412   gcc_unreachable ();
 413 }
 414
 415 /* FIXME: This is a hack to preserve trees that we create from the
 416    garbage collector.  */
 417
 418 static GTY(()) tree go_gc_root;
 419
 420 void
 421 go_preserve_from_gc (tree t)
 422 {
 423   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 424 }
 425
 426 /* Convert an identifier for use in an error message.  */
 427
 428 const char *
 429 go_localize_identifier (const char *ident)
 430 {
 431   return identifier_to_locale (ident);
 432 }
 433
 434 #undef LANG_HOOKS_NAME
 435 #undef LANG_HOOKS_INIT
 436 #undef LANG_HOOKS_OPTION_LANG_MASK
 437 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 438 #undef LANG_HOOKS_HANDLE_OPTION
 439 #undef LANG_HOOKS_POST_OPTIONS
 440 #undef LANG_HOOKS_PARSE_FILE
 441 #undef LANG_HOOKS_TYPE_FOR_MODE
 442 #undef LANG_HOOKS_TYPE_FOR_SIZE
 443 #undef LANG_HOOKS_BUILTIN_FUNCTION
 444 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 445 #undef LANG_HOOKS_PUSHDECL
 446 #undef LANG_HOOKS_GETDECLS
 447 #undef LANG_HOOKS_WRITE_GLOBALS
 448 #undef LANG_HOOKS_GIMPLIFY_EXPR
 449 #undef LANG_HOOKS_EH_PERSONALITY
 450
 451 #define LANG_HOOKS_NAME                 "GNU Go"
 452 #define LANG_HOOKS_INIT                 go_langhook_init
 453 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 454 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 455 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 456 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 457 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 458 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 459 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 460 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 461 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 462 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 463 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 464 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 465 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 466 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 467
 468 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 469
 470 #include "gt-go-go-lang.h"
 471 #include "gtype-go.h"