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