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