gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009, 2010, 2011 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 #include "common/common-target.h"
  39
  40 #include <mpfr.h>
  41
  42 #include "go-c.h"
  43
  44 /* Language-dependent contents of a type.  */
  45
  46 struct GTY(()) lang_type
  47 {
  48   char dummy;
  49 };
  50
  51 /* Language-dependent contents of a decl.  */
  52
  53 struct GTY(()) lang_decl
  54 {
  55   char dummy;
  56 };
  57
  58 /* Language-dependent contents of an identifier.  This must include a
  59    tree_identifier.  */
  60
  61 struct GTY(()) lang_identifier
  62 {
  63   struct tree_identifier common;
  64 };
  65
  66 /* The resulting tree type.  */
  67
  68 union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
  69            chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
  70 lang_tree_node
  71 {
  72   union tree_node GTY((tag ("0"),
  73                        desc ("tree_node_structure (&%h)"))) generic;
  74   struct lang_identifier GTY((tag ("1"))) identifier;
  75 };
  76
  77 /* We don't use language_function.  */
  78
  79 struct GTY(()) language_function
  80 {
  81   int dummy;
  82 };
  83
  84 /* Language hooks.  */
  85
  86 static bool
  87 go_langhook_init (void)
  88 {
  89   build_common_tree_nodes (false);
  90
  91   build_common_tree_nodes_2 (0);
  92
  93   /* We must create the gogo IR after calling build_common_tree_nodes
  94      (because Gogo::define_builtin_function_trees refers indirectly
  95      to, e.g., unsigned_char_type_node) but before calling
  96      build_common_builtin_nodes (because it calls, indirectly,
  97      go_type_for_size).  */
  98   go_create_gogo (INT_TYPE_SIZE, POINTER_SIZE);
  99
 100   build_common_builtin_nodes ();
 101
 102   /* I don't know why this is not done by any of the above.  */
 103   void_list_node = build_tree_list (NULL_TREE, void_type_node);
 104
 105   /* The default precision for floating point numbers.  This is used
 106      for floating point constants with abstract type.  This may
 107      eventually be controllable by a command line option.  */
 108   mpfr_set_default_prec (128);
 109
 110   /* Go uses exceptions.  */
 111   using_eh_for_cleanups ();
 112
 113   return true;
 114 }
 115
 116 /* The option mask.  */
 117
 118 static unsigned int
 119 go_langhook_option_lang_mask (void)
 120 {
 121   return CL_Go;
 122 }
 123
 124 /* Initialize the options structure.  */
 125
 126 static void
 127 go_langhook_init_options_struct (struct gcc_options *opts)
 128 {
 129   /* Go says that signed overflow is precisely defined.  */
 130   opts->x_flag_wrapv = 1;
 131
 132   /* We default to using strict aliasing, since Go pointers are safe.
 133      This is turned off for code that imports the "unsafe" package,
 134      because using unsafe.pointer violates C style aliasing
 135      requirements.  */
 136   opts->x_flag_strict_aliasing = 1;
 137
 138   /* Default to avoiding range issues for complex multiply and
 139      divide.  */
 140   opts->x_flag_complex_method = 2;
 141
 142   /* The builtin math functions should not set errno.  */
 143   opts->x_flag_errno_math = 0;
 144   opts->frontend_set_flag_errno_math = true;
 145
 146   /* We turn on stack splitting if we can.  */
 147   if (targetm_common.supports_split_stack (false, opts))
 148     opts->x_flag_split_stack = 1;
 149
 150   /* Exceptions are used to handle recovering from panics.  */
 151   opts->x_flag_exceptions = 1;
 152   opts->x_flag_non_call_exceptions = 1;
 153 }
 154
 155 /* Infrastructure for a VEC of char * pointers.  */
 156
 157 typedef const char *go_char_p;
 158 DEF_VEC_P(go_char_p);
 159 DEF_VEC_ALLOC_P(go_char_p, heap);
 160
 161 /* The list of directories to search after all the Go specific
 162    directories have been searched.  */
 163
 164 static VEC(go_char_p, heap) *go_search_dirs;
 165
 166 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 167
 168 static bool
 169 go_langhook_handle_option (
 170     size_t scode,
 171     const char *arg,
 172     int value ATTRIBUTE_UNUSED,
 173     int kind ATTRIBUTE_UNUSED,
 174     location_t loc ATTRIBUTE_UNUSED,
 175     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 176 {
 177   enum opt_code code = (enum opt_code) scode;
 178   bool ret = true;
 179
 180   switch (code)
 181     {
 182     case OPT_I:
 183       go_add_search_path (arg);
 184       break;
 185
 186     case OPT_L:
 187       /* A -L option is assumed to come from the compiler driver.
 188          This is a system directory.  We search the following
 189          directories, if they exist, before this one:
 190            dir/go/VERSION
 191            dir/go/VERSION/MACHINE
 192          This is like include/c++.  */
 193       {
 194         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 195         size_t len;
 196         char *p;
 197         struct stat st;
 198
 199         len = strlen (arg);
 200         p = XALLOCAVEC (char,
 201                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 202                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 203         strcpy (p, arg);
 204         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 205           strcat (p, dir_separator_str);
 206         strcat (p, "go");
 207         strcat (p, dir_separator_str);
 208         strcat (p, DEFAULT_TARGET_VERSION);
 209         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 210           {
 211             go_add_search_path (p);
 212             strcat (p, dir_separator_str);
 213             strcat (p, DEFAULT_TARGET_MACHINE);
 214             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 215               go_add_search_path (p);
 216           }
 217
 218         /* Search ARG too, but only after we've searched to Go
 219            specific directories for all -L arguments.  */
 220         VEC_safe_push (go_char_p, heap, go_search_dirs, arg);
 221       }
 222       break;
 223
 224     case OPT_fgo_dump_:
 225       ret = go_enable_dump (arg) ? true : false;
 226       break;
 227
 228     case OPT_fgo_prefix_:
 229       go_set_prefix (arg);
 230       break;
 231
 232     default:
 233       /* Just return 1 to indicate that the option is valid.  */
 234       break;
 235     }
 236
 237   return ret;
 238 }
 239
 240 /* Run after parsing options.  */
 241
 242 static bool
 243 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 244 {
 245   unsigned int ix;
 246   const char *dir;
 247
 248   gcc_assert (num_in_fnames > 0);
 249
 250   FOR_EACH_VEC_ELT (go_char_p, go_search_dirs, ix, dir)
 251     go_add_search_path (dir);
 252   VEC_free (go_char_p, heap, go_search_dirs);
 253   go_search_dirs = NULL;
 254
 255   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 256     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 257
 258   /* Returning false means that the backend should be used.  */
 259   return false;
 260 }
 261
 262 static void
 263 go_langhook_parse_file (void)
 264 {
 265   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 266                         go_require_return_statement);
 267 }
 268
 269 static tree
 270 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 271 {
 272   return go_type_for_size (bits, unsignedp);
 273 }
 274
 275 static tree
 276 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 277 {
 278   /* Go has no vector types.  Build them here.  FIXME: It does not
 279      make sense for the middle-end to ask the frontend for a type
 280      which the frontend does not support.  However, at least for now
 281      it is required.  See PR 46805.  */
 282   if (VECTOR_MODE_P (mode))
 283     {
 284       tree inner;
 285
 286       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 287       if (inner != NULL_TREE)
 288         return build_vector_type_for_mode (inner, mode);
 289       return NULL_TREE;
 290     }
 291
 292   return go_type_for_mode (mode, unsignedp);
 293 }
 294
 295 /* Record a builtin function.  We just ignore builtin functions.  */
 296
 297 static tree
 298 go_langhook_builtin_function (tree decl)
 299 {
 300   return decl;
 301 }
 302
 303 /* Return true if we are in the global binding level.  */
 304
 305 static bool
 306 go_langhook_global_bindings_p (void)
 307 {
 308   return current_function_decl == NULL_TREE;
 309 }
 310
 311 /* Push a declaration into the current binding level.  We can't
 312    usefully implement this since we don't want to convert from tree
 313    back to one of our internal data structures.  I think the only way
 314    this is used is to record a decl which is to be returned by
 315    getdecls, and we could implement it for that purpose if
 316    necessary.  */
 317
 318 static tree
 319 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 320 {
 321   gcc_unreachable ();
 322 }
 323
 324 /* This hook is used to get the current list of declarations as trees.
 325    We don't support that; instead we use the write_globals hook.  This
 326    can't simply crash because it is called by -gstabs.  */
 327
 328 static tree
 329 go_langhook_getdecls (void)
 330 {
 331   return NULL;
 332 }
 333
 334 /* Write out globals.  */
 335
 336 static void
 337 go_langhook_write_globals (void)
 338 {
 339   go_write_globals ();
 340 }
 341
 342 /* Go specific gimplification.  We need to gimplify
 343    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 344    it.  */
 345
 346 static int
 347 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 348 {
 349   if (TREE_CODE (*expr_p) == CALL_EXPR
 350       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 351     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 352                    is_gimple_val, fb_rvalue);
 353   return GS_UNHANDLED;
 354 }
 355
 356 /* Return a decl for the exception personality function.  The function
 357    itself is implemented in libgo/runtime/go-unwind.c.  */
 358
 359 static tree
 360 go_langhook_eh_personality (void)
 361 {
 362   static tree personality_decl;
 363   if (personality_decl == NULL_TREE)
 364     {
 365       personality_decl = build_personality_function ("gccgo");
 366       go_preserve_from_gc (personality_decl);
 367     }
 368   return personality_decl;
 369 }
 370
 371 /* Functions called directly by the generic backend.  */
 372
 373 tree
 374 convert (tree type, tree expr)
 375 {
 376   if (type == error_mark_node
 377       || expr == error_mark_node
 378       || TREE_TYPE (expr) == error_mark_node)
 379     return error_mark_node;
 380
 381   if (type == TREE_TYPE (expr))
 382     return expr;
 383
 384   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 385     return fold_convert (type, expr);
 386
 387   switch (TREE_CODE (type))
 388     {
 389     case VOID_TYPE:
 390     case BOOLEAN_TYPE:
 391       return fold_convert (type, expr);
 392     case INTEGER_TYPE:
 393       return fold (convert_to_integer (type, expr));
 394     case POINTER_TYPE:
 395       return fold (convert_to_pointer (type, expr));
 396     case REAL_TYPE:
 397       return fold (convert_to_real (type, expr));
 398     case COMPLEX_TYPE:
 399       return fold (convert_to_complex (type, expr));
 400     default:
 401       break;
 402     }
 403
 404   gcc_unreachable ();
 405 }
 406
 407 /* FIXME: This is a hack to preserve trees that we create from the
 408    garbage collector.  */
 409
 410 static GTY(()) tree go_gc_root;
 411
 412 void
 413 go_preserve_from_gc (tree t)
 414 {
 415   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 416 }
 417
 418 /* Convert an identifier for use in an error message.  */
 419
 420 const char *
 421 go_localize_identifier (const char *ident)
 422 {
 423   return identifier_to_locale (ident);
 424 }
 425
 426 #undef LANG_HOOKS_NAME
 427 #undef LANG_HOOKS_INIT
 428 #undef LANG_HOOKS_OPTION_LANG_MASK
 429 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 430 #undef LANG_HOOKS_HANDLE_OPTION
 431 #undef LANG_HOOKS_POST_OPTIONS
 432 #undef LANG_HOOKS_PARSE_FILE
 433 #undef LANG_HOOKS_TYPE_FOR_MODE
 434 #undef LANG_HOOKS_TYPE_FOR_SIZE
 435 #undef LANG_HOOKS_BUILTIN_FUNCTION
 436 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 437 #undef LANG_HOOKS_PUSHDECL
 438 #undef LANG_HOOKS_GETDECLS
 439 #undef LANG_HOOKS_WRITE_GLOBALS
 440 #undef LANG_HOOKS_GIMPLIFY_EXPR
 441 #undef LANG_HOOKS_EH_PERSONALITY
 442
 443 #define LANG_HOOKS_NAME                 "GNU Go"
 444 #define LANG_HOOKS_INIT                 go_langhook_init
 445 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 446 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 447 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 448 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 449 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 450 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 451 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 452 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 453 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 454 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 455 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 456 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 457 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 458 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 459
 460 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 461
 462 #include "gt-go-go-lang.h"
 463 #include "gtype-go.h"