gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009, 2010, 2011, 2012 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((variable_size)) 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 /* Option information we need to pass to go_create_gogo.  */
  85
  86 static const char *go_pkgpath = NULL;
  87 static const char *go_prefix = NULL;
  88 static const char *go_relative_import_path = NULL;
  89
  90 /* Language hooks.  */
  91
  92 static bool
  93 go_langhook_init (void)
  94 {
  95   build_common_tree_nodes (false, false);
  96
  97   /* I don't know why this has to be done explicitly.  */
  98   void_list_node = build_tree_list (NULL_TREE, void_type_node);
  99
 100   /* We must create the gogo IR after calling build_common_tree_nodes
 101      (because Gogo::define_builtin_function_trees refers indirectly
 102      to, e.g., unsigned_char_type_node) but before calling
 103      build_common_builtin_nodes (because it calls, indirectly,
 104      go_type_for_size).  */
 105   go_create_gogo (INT_TYPE_SIZE, POINTER_SIZE, go_pkgpath, go_prefix,
 106                   go_relative_import_path);
 107
 108   build_common_builtin_nodes ();
 109
 110   /* The default precision for floating point numbers.  This is used
 111      for floating point constants with abstract type.  This may
 112      eventually be controllable by a command line option.  */
 113   mpfr_set_default_prec (256);
 114
 115   /* Go uses exceptions.  */
 116   using_eh_for_cleanups ();
 117
 118   return true;
 119 }
 120
 121 /* The option mask.  */
 122
 123 static unsigned int
 124 go_langhook_option_lang_mask (void)
 125 {
 126   return CL_Go;
 127 }
 128
 129 /* Initialize the options structure.  */
 130
 131 static void
 132 go_langhook_init_options_struct (struct gcc_options *opts)
 133 {
 134   /* Go says that signed overflow is precisely defined.  */
 135   opts->x_flag_wrapv = 1;
 136
 137   /* We default to using strict aliasing, since Go pointers are safe.
 138      This is turned off for code that imports the "unsafe" package,
 139      because using unsafe.pointer violates C style aliasing
 140      requirements.  */
 141   opts->x_flag_strict_aliasing = 1;
 142
 143   /* Default to avoiding range issues for complex multiply and
 144      divide.  */
 145   opts->x_flag_complex_method = 2;
 146
 147   /* The builtin math functions should not set errno.  */
 148   opts->x_flag_errno_math = 0;
 149   opts->frontend_set_flag_errno_math = true;
 150
 151   /* We turn on stack splitting if we can.  */
 152   if (targetm_common.supports_split_stack (false, opts))
 153     opts->x_flag_split_stack = 1;
 154
 155   /* Exceptions are used to handle recovering from panics.  */
 156   opts->x_flag_exceptions = 1;
 157   opts->x_flag_non_call_exceptions = 1;
 158 }
 159
 160 /* Infrastructure for a vector of char * pointers.  */
 161
 162 typedef const char *go_char_p;
 163
 164 /* The list of directories to search after all the Go specific
 165    directories have been searched.  */
 166
 167 static vec<go_char_p> go_search_dirs;
 168
 169 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 170
 171 static bool
 172 go_langhook_handle_option (
 173     size_t scode,
 174     const char *arg,
 175     int value ATTRIBUTE_UNUSED,
 176     int kind ATTRIBUTE_UNUSED,
 177     location_t loc ATTRIBUTE_UNUSED,
 178     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 179 {
 180   enum opt_code code = (enum opt_code) scode;
 181   bool ret = true;
 182
 183   switch (code)
 184     {
 185     case OPT_I:
 186       go_add_search_path (arg);
 187       break;
 188
 189     case OPT_L:
 190       /* A -L option is assumed to come from the compiler driver.
 191          This is a system directory.  We search the following
 192          directories, if they exist, before this one:
 193            dir/go/VERSION
 194            dir/go/VERSION/MACHINE
 195          This is like include/c++.  */
 196       {
 197         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 198         size_t len;
 199         char *p;
 200         struct stat st;
 201
 202         len = strlen (arg);
 203         p = XALLOCAVEC (char,
 204                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 205                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 206         strcpy (p, arg);
 207         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 208           strcat (p, dir_separator_str);
 209         strcat (p, "go");
 210         strcat (p, dir_separator_str);
 211         strcat (p, DEFAULT_TARGET_VERSION);
 212         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 213           {
 214             go_add_search_path (p);
 215             strcat (p, dir_separator_str);
 216             strcat (p, DEFAULT_TARGET_MACHINE);
 217             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 218               go_add_search_path (p);
 219           }
 220
 221         /* Search ARG too, but only after we've searched to Go
 222            specific directories for all -L arguments.  */
 223         go_search_dirs.safe_push (arg);
 224       }
 225       break;
 226
 227     case OPT_fgo_dump_:
 228       ret = go_enable_dump (arg) ? true : false;
 229       break;
 230
 231     case OPT_fgo_optimize_:
 232       ret = go_enable_optimize (arg) ? true : false;
 233       break;
 234
 235     case OPT_fgo_pkgpath_:
 236       go_pkgpath = arg;
 237       break;
 238
 239     case OPT_fgo_prefix_:
 240       go_prefix = arg;
 241       break;
 242
 243     case OPT_fgo_relative_import_path_:
 244       go_relative_import_path = arg;
 245       break;
 246
 247     default:
 248       /* Just return 1 to indicate that the option is valid.  */
 249       break;
 250     }
 251
 252   return ret;
 253 }
 254
 255 /* Run after parsing options.  */
 256
 257 static bool
 258 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 259 {
 260   unsigned int ix;
 261   const char *dir;
 262
 263   gcc_assert (num_in_fnames > 0);
 264
 265   FOR_EACH_VEC_ELT (go_search_dirs, ix, dir)
 266     go_add_search_path (dir);
 267   go_search_dirs.release ();
 268
 269   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 270     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 271
 272   /* Returning false means that the backend should be used.  */
 273   return false;
 274 }
 275
 276 static void
 277 go_langhook_parse_file (void)
 278 {
 279   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 280                         go_require_return_statement);
 281 }
 282
 283 static tree
 284 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 285 {
 286   return go_type_for_size (bits, unsignedp);
 287 }
 288
 289 static tree
 290 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 291 {
 292   tree type;
 293   /* Go has no vector types.  Build them here.  FIXME: It does not
 294      make sense for the middle-end to ask the frontend for a type
 295      which the frontend does not support.  However, at least for now
 296      it is required.  See PR 46805.  */
 297   if (VECTOR_MODE_P (mode))
 298     {
 299       tree inner;
 300
 301       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 302       if (inner != NULL_TREE)
 303         return build_vector_type_for_mode (inner, mode);
 304       return NULL_TREE;
 305     }
 306
 307   type = go_type_for_mode (mode, unsignedp);
 308   if (type)
 309     return type;
 310
 311 #if HOST_BITS_PER_WIDE_INT >= 64
 312   /* The middle-end and some backends rely on TImode being supported
 313      for 64-bit HWI.  */
 314   if (mode == TImode)
 315     {
 316       type = build_nonstandard_integer_type (GET_MODE_BITSIZE (TImode),
 317                                              unsignedp);
 318       if (type && TYPE_MODE (type) == TImode)
 319         return type;
 320     }
 321 #endif
 322   return NULL_TREE;
 323 }
 324
 325 /* Record a builtin function.  We just ignore builtin functions.  */
 326
 327 static tree
 328 go_langhook_builtin_function (tree decl)
 329 {
 330   return decl;
 331 }
 332
 333 /* Return true if we are in the global binding level.  */
 334
 335 static bool
 336 go_langhook_global_bindings_p (void)
 337 {
 338   return current_function_decl == NULL_TREE;
 339 }
 340
 341 /* Push a declaration into the current binding level.  We can't
 342    usefully implement this since we don't want to convert from tree
 343    back to one of our internal data structures.  I think the only way
 344    this is used is to record a decl which is to be returned by
 345    getdecls, and we could implement it for that purpose if
 346    necessary.  */
 347
 348 static tree
 349 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 350 {
 351   gcc_unreachable ();
 352 }
 353
 354 /* This hook is used to get the current list of declarations as trees.
 355    We don't support that; instead we use the write_globals hook.  This
 356    can't simply crash because it is called by -gstabs.  */
 357
 358 static tree
 359 go_langhook_getdecls (void)
 360 {
 361   return NULL;
 362 }
 363
 364 /* Write out globals.  */
 365
 366 static void
 367 go_langhook_write_globals (void)
 368 {
 369   go_write_globals ();
 370 }
 371
 372 /* Go specific gimplification.  We need to gimplify
 373    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 374    it.  */
 375
 376 static int
 377 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 378 {
 379   if (TREE_CODE (*expr_p) == CALL_EXPR
 380       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 381     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 382                    is_gimple_val, fb_rvalue);
 383   return GS_UNHANDLED;
 384 }
 385
 386 /* Return a decl for the exception personality function.  The function
 387    itself is implemented in libgo/runtime/go-unwind.c.  */
 388
 389 static tree
 390 go_langhook_eh_personality (void)
 391 {
 392   static tree personality_decl;
 393   if (personality_decl == NULL_TREE)
 394     {
 395       personality_decl = build_personality_function ("gccgo");
 396       go_preserve_from_gc (personality_decl);
 397     }
 398   return personality_decl;
 399 }
 400
 401 /* Functions called directly by the generic backend.  */
 402
 403 tree
 404 convert (tree type, tree expr)
 405 {
 406   if (type == error_mark_node
 407       || expr == error_mark_node
 408       || TREE_TYPE (expr) == error_mark_node)
 409     return error_mark_node;
 410
 411   if (type == TREE_TYPE (expr))
 412     return expr;
 413
 414   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 415     return fold_convert (type, expr);
 416
 417   switch (TREE_CODE (type))
 418     {
 419     case VOID_TYPE:
 420     case BOOLEAN_TYPE:
 421       return fold_convert (type, expr);
 422     case INTEGER_TYPE:
 423       return fold (convert_to_integer (type, expr));
 424     case POINTER_TYPE:
 425       return fold (convert_to_pointer (type, expr));
 426     case REAL_TYPE:
 427       return fold (convert_to_real (type, expr));
 428     case COMPLEX_TYPE:
 429       return fold (convert_to_complex (type, expr));
 430     default:
 431       break;
 432     }
 433
 434   gcc_unreachable ();
 435 }
 436
 437 /* FIXME: This is a hack to preserve trees that we create from the
 438    garbage collector.  */
 439
 440 static GTY(()) tree go_gc_root;
 441
 442 void
 443 go_preserve_from_gc (tree t)
 444 {
 445   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 446 }
 447
 448 /* Convert an identifier for use in an error message.  */
 449
 450 const char *
 451 go_localize_identifier (const char *ident)
 452 {
 453   return identifier_to_locale (ident);
 454 }
 455
 456 #undef LANG_HOOKS_NAME
 457 #undef LANG_HOOKS_INIT
 458 #undef LANG_HOOKS_OPTION_LANG_MASK
 459 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 460 #undef LANG_HOOKS_HANDLE_OPTION
 461 #undef LANG_HOOKS_POST_OPTIONS
 462 #undef LANG_HOOKS_PARSE_FILE
 463 #undef LANG_HOOKS_TYPE_FOR_MODE
 464 #undef LANG_HOOKS_TYPE_FOR_SIZE
 465 #undef LANG_HOOKS_BUILTIN_FUNCTION
 466 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 467 #undef LANG_HOOKS_PUSHDECL
 468 #undef LANG_HOOKS_GETDECLS
 469 #undef LANG_HOOKS_WRITE_GLOBALS
 470 #undef LANG_HOOKS_GIMPLIFY_EXPR
 471 #undef LANG_HOOKS_EH_PERSONALITY
 472
 473 #define LANG_HOOKS_NAME                 "GNU Go"
 474 #define LANG_HOOKS_INIT                 go_langhook_init
 475 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 476 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 477 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 478 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 479 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 480 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 481 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 482 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 483 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 484 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 485 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 486 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 487 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 488 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 489
 490 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 491
 492 #include "gt-go-go-lang.h"
 493 #include "gtype-go.h"