gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009-2013 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 "target.h"
  37 #include "common/common-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((variable_size)) 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 ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
  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 /* Option information we need to pass to go_create_gogo.  */
  84
  85 static const char *go_pkgpath = NULL;
  86 static const char *go_prefix = NULL;
  87 static const char *go_relative_import_path = NULL;
  88
  89 /* Language hooks.  */
  90
  91 static bool
  92 go_langhook_init (void)
  93 {
  94   build_common_tree_nodes (false, false);
  95
  96   /* I don't know why this has to be done explicitly.  */
  97   void_list_node = build_tree_list (NULL_TREE, void_type_node);
  98
  99   /* We must create the gogo IR after calling build_common_tree_nodes
 100      (because Gogo::define_builtin_function_trees refers indirectly
 101      to, e.g., unsigned_char_type_node) but before calling
 102      build_common_builtin_nodes (because it calls, indirectly,
 103      go_type_for_size).  */
 104   go_create_gogo (INT_TYPE_SIZE, POINTER_SIZE, go_pkgpath, go_prefix,
 105                   go_relative_import_path);
 106
 107   build_common_builtin_nodes ();
 108
 109   /* The default precision for floating point numbers.  This is used
 110      for floating point constants with abstract type.  This may
 111      eventually be controllable by a command line option.  */
 112   mpfr_set_default_prec (256);
 113
 114   /* Go uses exceptions.  */
 115   using_eh_for_cleanups ();
 116
 117   return true;
 118 }
 119
 120 /* The option mask.  */
 121
 122 static unsigned int
 123 go_langhook_option_lang_mask (void)
 124 {
 125   return CL_Go;
 126 }
 127
 128 /* Initialize the options structure.  */
 129
 130 static void
 131 go_langhook_init_options_struct (struct gcc_options *opts)
 132 {
 133   /* Go says that signed overflow is precisely defined.  */
 134   opts->x_flag_wrapv = 1;
 135
 136   /* We default to using strict aliasing, since Go pointers are safe.
 137      This is turned off for code that imports the "unsafe" package,
 138      because using unsafe.pointer violates C style aliasing
 139      requirements.  */
 140   opts->x_flag_strict_aliasing = 1;
 141
 142   /* Default to avoiding range issues for complex multiply and
 143      divide.  */
 144   opts->x_flag_complex_method = 2;
 145
 146   /* The builtin math functions should not set errno.  */
 147   opts->x_flag_errno_math = 0;
 148   opts->frontend_set_flag_errno_math = true;
 149
 150   /* We turn on stack splitting if we can.  */
 151   if (targetm_common.supports_split_stack (false, opts))
 152     opts->x_flag_split_stack = 1;
 153
 154   /* Exceptions are used to handle recovering from panics.  */
 155   opts->x_flag_exceptions = 1;
 156   opts->x_flag_non_call_exceptions = 1;
 157 }
 158
 159 /* Infrastructure for a vector of char * pointers.  */
 160
 161 typedef const char *go_char_p;
 162
 163 /* The list of directories to search after all the Go specific
 164    directories have been searched.  */
 165
 166 static vec<go_char_p> go_search_dirs;
 167
 168 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 169
 170 static bool
 171 go_langhook_handle_option (
 172     size_t scode,
 173     const char *arg,
 174     int value ATTRIBUTE_UNUSED,
 175     int kind ATTRIBUTE_UNUSED,
 176     location_t loc ATTRIBUTE_UNUSED,
 177     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 178 {
 179   enum opt_code code = (enum opt_code) scode;
 180   bool ret = true;
 181
 182   switch (code)
 183     {
 184     case OPT_I:
 185       go_add_search_path (arg);
 186       break;
 187
 188     case OPT_L:
 189       /* A -L option is assumed to come from the compiler driver.
 190          This is a system directory.  We search the following
 191          directories, if they exist, before this one:
 192            dir/go/VERSION
 193            dir/go/VERSION/MACHINE
 194          This is like include/c++.  */
 195       {
 196         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 197         size_t len;
 198         char *p;
 199         struct stat st;
 200
 201         len = strlen (arg);
 202         p = XALLOCAVEC (char,
 203                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 204                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 205         strcpy (p, arg);
 206         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 207           strcat (p, dir_separator_str);
 208         strcat (p, "go");
 209         strcat (p, dir_separator_str);
 210         strcat (p, DEFAULT_TARGET_VERSION);
 211         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 212           {
 213             go_add_search_path (p);
 214             strcat (p, dir_separator_str);
 215             strcat (p, DEFAULT_TARGET_MACHINE);
 216             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 217               go_add_search_path (p);
 218           }
 219
 220         /* Search ARG too, but only after we've searched to Go
 221            specific directories for all -L arguments.  */
 222         go_search_dirs.safe_push (arg);
 223       }
 224       break;
 225
 226     case OPT_fgo_dump_:
 227       ret = go_enable_dump (arg) ? true : false;
 228       break;
 229
 230     case OPT_fgo_optimize_:
 231       ret = go_enable_optimize (arg) ? true : false;
 232       break;
 233
 234     case OPT_fgo_pkgpath_:
 235       go_pkgpath = arg;
 236       break;
 237
 238     case OPT_fgo_prefix_:
 239       go_prefix = arg;
 240       break;
 241
 242     case OPT_fgo_relative_import_path_:
 243       go_relative_import_path = arg;
 244       break;
 245
 246     default:
 247       /* Just return 1 to indicate that the option is valid.  */
 248       break;
 249     }
 250
 251   return ret;
 252 }
 253
 254 /* Run after parsing options.  */
 255
 256 static bool
 257 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 258 {
 259   unsigned int ix;
 260   const char *dir;
 261
 262   gcc_assert (num_in_fnames > 0);
 263
 264   FOR_EACH_VEC_ELT (go_search_dirs, ix, dir)
 265     go_add_search_path (dir);
 266   go_search_dirs.release ();
 267
 268   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 269     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 270
 271   /* Returning false means that the backend should be used.  */
 272   return false;
 273 }
 274
 275 static void
 276 go_langhook_parse_file (void)
 277 {
 278   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 279                         go_require_return_statement);
 280 }
 281
 282 static tree
 283 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 284 {
 285   return go_type_for_size (bits, unsignedp);
 286 }
 287
 288 static tree
 289 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 290 {
 291   tree type;
 292   /* Go has no vector types.  Build them here.  FIXME: It does not
 293      make sense for the middle-end to ask the frontend for a type
 294      which the frontend does not support.  However, at least for now
 295      it is required.  See PR 46805.  */
 296   if (VECTOR_MODE_P (mode))
 297     {
 298       tree inner;
 299
 300       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 301       if (inner != NULL_TREE)
 302         return build_vector_type_for_mode (inner, mode);
 303       return NULL_TREE;
 304     }
 305
 306   type = go_type_for_mode (mode, unsignedp);
 307   if (type)
 308     return type;
 309
 310 #if HOST_BITS_PER_WIDE_INT >= 64
 311   /* The middle-end and some backends rely on TImode being supported
 312      for 64-bit HWI.  */
 313   if (mode == TImode)
 314     {
 315       type = build_nonstandard_integer_type (GET_MODE_BITSIZE (TImode),
 316                                              unsignedp);
 317       if (type && TYPE_MODE (type) == TImode)
 318         return type;
 319     }
 320 #endif
 321   return NULL_TREE;
 322 }
 323
 324 /* Record a builtin function.  We just ignore builtin functions.  */
 325
 326 static tree
 327 go_langhook_builtin_function (tree decl)
 328 {
 329   return decl;
 330 }
 331
 332 /* Return true if we are in the global binding level.  */
 333
 334 static bool
 335 go_langhook_global_bindings_p (void)
 336 {
 337   return current_function_decl == NULL_TREE;
 338 }
 339
 340 /* Push a declaration into the current binding level.  We can't
 341    usefully implement this since we don't want to convert from tree
 342    back to one of our internal data structures.  I think the only way
 343    this is used is to record a decl which is to be returned by
 344    getdecls, and we could implement it for that purpose if
 345    necessary.  */
 346
 347 static tree
 348 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 349 {
 350   gcc_unreachable ();
 351 }
 352
 353 /* This hook is used to get the current list of declarations as trees.
 354    We don't support that; instead we use the write_globals hook.  This
 355    can't simply crash because it is called by -gstabs.  */
 356
 357 static tree
 358 go_langhook_getdecls (void)
 359 {
 360   return NULL;
 361 }
 362
 363 /* Write out globals.  */
 364
 365 static void
 366 go_langhook_write_globals (void)
 367 {
 368   go_write_globals ();
 369 }
 370
 371 /* Go specific gimplification.  We need to gimplify
 372    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 373    it.  */
 374
 375 static int
 376 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 377 {
 378   if (TREE_CODE (*expr_p) == CALL_EXPR
 379       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 380     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 381                    is_gimple_val, fb_rvalue);
 382   return GS_UNHANDLED;
 383 }
 384
 385 /* Return a decl for the exception personality function.  The function
 386    itself is implemented in libgo/runtime/go-unwind.c.  */
 387
 388 static tree
 389 go_langhook_eh_personality (void)
 390 {
 391   static tree personality_decl;
 392   if (personality_decl == NULL_TREE)
 393     {
 394       personality_decl = build_personality_function ("gccgo");
 395       go_preserve_from_gc (personality_decl);
 396     }
 397   return personality_decl;
 398 }
 399
 400 /* Functions called directly by the generic backend.  */
 401
 402 tree
 403 convert (tree type, tree expr)
 404 {
 405   if (type == error_mark_node
 406       || expr == error_mark_node
 407       || TREE_TYPE (expr) == error_mark_node)
 408     return error_mark_node;
 409
 410   if (type == TREE_TYPE (expr))
 411     return expr;
 412
 413   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 414     return fold_convert (type, expr);
 415
 416   switch (TREE_CODE (type))
 417     {
 418     case VOID_TYPE:
 419     case BOOLEAN_TYPE:
 420       return fold_convert (type, expr);
 421     case INTEGER_TYPE:
 422       return fold (convert_to_integer (type, expr));
 423     case POINTER_TYPE:
 424       return fold (convert_to_pointer (type, expr));
 425     case REAL_TYPE:
 426       return fold (convert_to_real (type, expr));
 427     case COMPLEX_TYPE:
 428       return fold (convert_to_complex (type, expr));
 429     default:
 430       break;
 431     }
 432
 433   gcc_unreachable ();
 434 }
 435
 436 /* FIXME: This is a hack to preserve trees that we create from the
 437    garbage collector.  */
 438
 439 static GTY(()) tree go_gc_root;
 440
 441 void
 442 go_preserve_from_gc (tree t)
 443 {
 444   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 445 }
 446
 447 /* Convert an identifier for use in an error message.  */
 448
 449 const char *
 450 go_localize_identifier (const char *ident)
 451 {
 452   return identifier_to_locale (ident);
 453 }
 454
 455 #undef LANG_HOOKS_NAME
 456 #undef LANG_HOOKS_INIT
 457 #undef LANG_HOOKS_OPTION_LANG_MASK
 458 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 459 #undef LANG_HOOKS_HANDLE_OPTION
 460 #undef LANG_HOOKS_POST_OPTIONS
 461 #undef LANG_HOOKS_PARSE_FILE
 462 #undef LANG_HOOKS_TYPE_FOR_MODE
 463 #undef LANG_HOOKS_TYPE_FOR_SIZE
 464 #undef LANG_HOOKS_BUILTIN_FUNCTION
 465 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 466 #undef LANG_HOOKS_PUSHDECL
 467 #undef LANG_HOOKS_GETDECLS
 468 #undef LANG_HOOKS_WRITE_GLOBALS
 469 #undef LANG_HOOKS_GIMPLIFY_EXPR
 470 #undef LANG_HOOKS_EH_PERSONALITY
 471
 472 #define LANG_HOOKS_NAME                 "GNU Go"
 473 #define LANG_HOOKS_INIT                 go_langhook_init
 474 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 475 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 476 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 477 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 478 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 479 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 480 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 481 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 482 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 483 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 484 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 485 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 486 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 487 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 488
 489 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 490
 491 #include "gt-go-go-lang.h"
 492 #include "gtype-go.h"