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
  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, 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   opts->frontend_set_flag_errno_math = true;
 153
 154   /* We turn on stack splitting if we can.  */
 155   if (targetm.supports_split_stack (false, opts))
 156     opts->x_flag_split_stack = 1;
 157
 158   /* Exceptions are used to handle recovering from panics.  */
 159   opts->x_flag_exceptions = 1;
 160   opts->x_flag_non_call_exceptions = 1;
 161 }
 162
 163 /* Infrastructure for a VEC of char * pointers.  */
 164
 165 typedef const char *go_char_p;
 166 DEF_VEC_P(go_char_p);
 167 DEF_VEC_ALLOC_P(go_char_p, heap);
 168
 169 /* The list of directories to search after all the Go specific
 170    directories have been searched.  */
 171
 172 static VEC(go_char_p, heap) *go_search_dirs;
 173
 174 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 175
 176 static bool
 177 go_langhook_handle_option (
 178     size_t scode,
 179     const char *arg,
 180     int value ATTRIBUTE_UNUSED,
 181     int kind ATTRIBUTE_UNUSED,
 182     location_t loc ATTRIBUTE_UNUSED,
 183     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 184 {
 185   enum opt_code code = (enum opt_code) scode;
 186   bool ret = true;
 187
 188   switch (code)
 189     {
 190     case OPT_I:
 191       go_add_search_path (arg);
 192       break;
 193
 194     case OPT_L:
 195       /* A -L option is assumed to come from the compiler driver.
 196          This is a system directory.  We search the following
 197          directories, if they exist, before this one:
 198            dir/go/VERSION
 199            dir/go/VERSION/MACHINE
 200          This is like include/c++.  */
 201       {
 202         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 203         size_t len;
 204         char *p;
 205         struct stat st;
 206
 207         len = strlen (arg);
 208         p = XALLOCAVEC (char,
 209                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 210                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 211         strcpy (p, arg);
 212         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 213           strcat (p, dir_separator_str);
 214         strcat (p, "go");
 215         strcat (p, dir_separator_str);
 216         strcat (p, DEFAULT_TARGET_VERSION);
 217         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 218           {
 219             go_add_search_path (p);
 220             strcat (p, dir_separator_str);
 221             strcat (p, DEFAULT_TARGET_MACHINE);
 222             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 223               go_add_search_path (p);
 224           }
 225
 226         /* Search ARG too, but only after we've searched to Go
 227            specific directories for all -L arguments.  */
 228         VEC_safe_push (go_char_p, heap, go_search_dirs, arg);
 229       }
 230       break;
 231
 232     case OPT_fgo_dump_:
 233       ret = go_enable_dump (arg) ? true : false;
 234       break;
 235
 236     case OPT_fgo_prefix_:
 237       go_set_prefix (arg);
 238       break;
 239
 240     default:
 241       /* Just return 1 to indicate that the option is valid.  */
 242       break;
 243     }
 244
 245   return ret;
 246 }
 247
 248 /* Run after parsing options.  */
 249
 250 static bool
 251 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 252 {
 253   unsigned int ix;
 254   const char *dir;
 255
 256   gcc_assert (num_in_fnames > 0);
 257
 258   FOR_EACH_VEC_ELT (go_char_p, go_search_dirs, ix, dir)
 259     go_add_search_path (dir);
 260   VEC_free (go_char_p, heap, go_search_dirs);
 261   go_search_dirs = NULL;
 262
 263   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 264     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 265
 266   /* Returning false means that the backend should be used.  */
 267   return false;
 268 }
 269
 270 static void
 271 go_langhook_parse_file (void)
 272 {
 273   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 274                         go_require_return_statement);
 275 }
 276
 277 static tree
 278 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 279 {
 280   return go_type_for_size (bits, unsignedp);
 281 }
 282
 283 static tree
 284 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 285 {
 286   /* Go has no vector types.  Build them here.  FIXME: It does not
 287      make sense for the middle-end to ask the frontend for a type
 288      which the frontend does not support.  However, at least for now
 289      it is required.  See PR 46805.  */
 290   if (VECTOR_MODE_P (mode))
 291     {
 292       tree inner;
 293
 294       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 295       if (inner != NULL_TREE)
 296         return build_vector_type_for_mode (inner, mode);
 297       return NULL_TREE;
 298     }
 299
 300   return go_type_for_mode (mode, unsignedp);
 301 }
 302
 303 /* Record a builtin function.  We just ignore builtin functions.  */
 304
 305 static tree
 306 go_langhook_builtin_function (tree decl)
 307 {
 308   return decl;
 309 }
 310
 311 static int
 312 go_langhook_global_bindings_p (void)
 313 {
 314   return current_function_decl == NULL ? 1 : 0;
 315 }
 316
 317 /* Push a declaration into the current binding level.  We can't
 318    usefully implement this since we don't want to convert from tree
 319    back to one of our internal data structures.  I think the only way
 320    this is used is to record a decl which is to be returned by
 321    getdecls, and we could implement it for that purpose if
 322    necessary.  */
 323
 324 static tree
 325 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 326 {
 327   gcc_unreachable ();
 328 }
 329
 330 /* This hook is used to get the current list of declarations as trees.
 331    We don't support that; instead we use the write_globals hook.  This
 332    can't simply crash because it is called by -gstabs.  */
 333
 334 static tree
 335 go_langhook_getdecls (void)
 336 {
 337   return NULL;
 338 }
 339
 340 /* Write out globals.  */
 341
 342 static void
 343 go_langhook_write_globals (void)
 344 {
 345   go_write_globals ();
 346 }
 347
 348 /* Go specific gimplification.  We need to gimplify
 349    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 350    it.  */
 351
 352 static int
 353 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 354 {
 355   if (TREE_CODE (*expr_p) == CALL_EXPR
 356       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 357     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 358                    is_gimple_val, fb_rvalue);
 359   return GS_UNHANDLED;
 360 }
 361
 362 /* Return a decl for the exception personality function.  The function
 363    itself is implemented in libgo/runtime/go-unwind.c.  */
 364
 365 static tree
 366 go_langhook_eh_personality (void)
 367 {
 368   static tree personality_decl;
 369   if (personality_decl == NULL_TREE)
 370     {
 371       personality_decl = build_personality_function ("gccgo");
 372       go_preserve_from_gc (personality_decl);
 373     }
 374   return personality_decl;
 375 }
 376
 377 /* Functions called directly by the generic backend.  */
 378
 379 tree
 380 convert (tree type, tree expr)
 381 {
 382   if (type == error_mark_node
 383       || expr == error_mark_node
 384       || TREE_TYPE (expr) == error_mark_node)
 385     return error_mark_node;
 386
 387   if (type == TREE_TYPE (expr))
 388     return expr;
 389
 390   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 391     return fold_convert (type, expr);
 392
 393   switch (TREE_CODE (type))
 394     {
 395     case VOID_TYPE:
 396     case BOOLEAN_TYPE:
 397       return fold_convert (type, expr);
 398     case INTEGER_TYPE:
 399       return fold (convert_to_integer (type, expr));
 400     case POINTER_TYPE:
 401       return fold (convert_to_pointer (type, expr));
 402     case REAL_TYPE:
 403       return fold (convert_to_real (type, expr));
 404     case COMPLEX_TYPE:
 405       return fold (convert_to_complex (type, expr));
 406     default:
 407       break;
 408     }
 409
 410   gcc_unreachable ();
 411 }
 412
 413 /* FIXME: This is a hack to preserve trees that we create from the
 414    garbage collector.  */
 415
 416 static GTY(()) tree go_gc_root;
 417
 418 void
 419 go_preserve_from_gc (tree t)
 420 {
 421   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 422 }
 423
 424 /* Convert an identifier for use in an error message.  */
 425
 426 const char *
 427 go_localize_identifier (const char *ident)
 428 {
 429   return identifier_to_locale (ident);
 430 }
 431
 432 #undef LANG_HOOKS_NAME
 433 #undef LANG_HOOKS_INIT
 434 #undef LANG_HOOKS_OPTION_LANG_MASK
 435 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 436 #undef LANG_HOOKS_HANDLE_OPTION
 437 #undef LANG_HOOKS_POST_OPTIONS
 438 #undef LANG_HOOKS_PARSE_FILE
 439 #undef LANG_HOOKS_TYPE_FOR_MODE
 440 #undef LANG_HOOKS_TYPE_FOR_SIZE
 441 #undef LANG_HOOKS_BUILTIN_FUNCTION
 442 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 443 #undef LANG_HOOKS_PUSHDECL
 444 #undef LANG_HOOKS_GETDECLS
 445 #undef LANG_HOOKS_WRITE_GLOBALS
 446 #undef LANG_HOOKS_GIMPLIFY_EXPR
 447 #undef LANG_HOOKS_EH_PERSONALITY
 448
 449 #define LANG_HOOKS_NAME                 "GNU Go"
 450 #define LANG_HOOKS_INIT                 go_langhook_init
 451 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 452 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 453 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 454 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 455 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 456 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 457 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 458 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 459 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 460 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 461 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 462 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 463 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 464 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 465
 466 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 467
 468 #include "gt-go-go-lang.h"
 469 #include "gtype-go.h"