gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009-2014 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 "basic-block.h"
  27 #include "gimple-expr.h"
  28 #include "gimplify.h"
  29 #include "stor-layout.h"
  30 #include "toplev.h"
  31 #include "debug.h"
  32 #include "options.h"
  33 #include "flags.h"
  34 #include "convert.h"
  35 #include "diagnostic.h"
  36 #include "langhooks.h"
  37 #include "langhooks-def.h"
  38 #include "target.h"
  39 #include "common/common-target.h"
  40
  41 #include <mpfr.h>
  42
  43 #include "go-c.h"
  44
  45 /* Language-dependent contents of a type.  */
  46
  47 struct GTY(()) lang_type
  48 {
  49   char dummy;
  50 };
  51
  52 /* Language-dependent contents of a decl.  */
  53
  54 struct GTY(()) lang_decl
  55 {
  56   char dummy;
  57 };
  58
  59 /* Language-dependent contents of an identifier.  This must include a
  60    tree_identifier.  */
  61
  62 struct GTY(()) lang_identifier
  63 {
  64   struct tree_identifier common;
  65 };
  66
  67 /* The resulting tree type.  */
  68
  69 union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
  70            chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
  71 lang_tree_node
  72 {
  73   union tree_node GTY((tag ("0"),
  74                        desc ("tree_node_structure (&%h)"))) generic;
  75   struct lang_identifier GTY((tag ("1"))) identifier;
  76 };
  77
  78 /* We don't use language_function.  */
  79
  80 struct GTY(()) language_function
  81 {
  82   int dummy;
  83 };
  84
  85 /* Option information we need to pass to go_create_gogo.  */
  86
  87 static const char *go_pkgpath = NULL;
  88 static const char *go_prefix = NULL;
  89 static const char *go_relative_import_path = NULL;
  90
  91 /* Language hooks.  */
  92
  93 static bool
  94 go_langhook_init (void)
  95 {
  96   build_common_tree_nodes (false, false);
  97
  98   /* I don't know why this has to be done explicitly.  */
  99   void_list_node = build_tree_list (NULL_TREE, void_type_node);
 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, go_pkgpath, go_prefix,
 107                   go_relative_import_path, go_check_divide_zero,
 108                   go_check_divide_overflow);
 109
 110   build_common_builtin_nodes ();
 111
 112   /* The default precision for floating point numbers.  This is used
 113      for floating point constants with abstract type.  This may
 114      eventually be controllable by a command line option.  */
 115   mpfr_set_default_prec (256);
 116
 117   /* Go uses exceptions.  */
 118   using_eh_for_cleanups ();
 119
 120   return true;
 121 }
 122
 123 /* The option mask.  */
 124
 125 static unsigned int
 126 go_langhook_option_lang_mask (void)
 127 {
 128   return CL_Go;
 129 }
 130
 131 /* Initialize the options structure.  */
 132
 133 static void
 134 go_langhook_init_options_struct (struct gcc_options *opts)
 135 {
 136   /* Go says that signed overflow is precisely defined.  */
 137   opts->x_flag_wrapv = 1;
 138
 139   /* We default to using strict aliasing, since Go pointers are safe.
 140      This is turned off for code that imports the "unsafe" package,
 141      because using unsafe.pointer violates C style aliasing
 142      requirements.  */
 143   opts->x_flag_strict_aliasing = 1;
 144
 145   /* Default to avoiding range issues for complex multiply and
 146      divide.  */
 147   opts->x_flag_complex_method = 2;
 148
 149   /* The builtin math functions should not set errno.  */
 150   opts->x_flag_errno_math = 0;
 151   opts->frontend_set_flag_errno_math = true;
 152
 153   /* We turn on stack splitting if we can.  */
 154   if (targetm_common.supports_split_stack (false, opts))
 155     opts->x_flag_split_stack = 1;
 156
 157   /* Exceptions are used to handle recovering from panics.  */
 158   opts->x_flag_exceptions = 1;
 159   opts->x_flag_non_call_exceptions = 1;
 160 }
 161
 162 /* Infrastructure for a vector of char * pointers.  */
 163
 164 typedef const char *go_char_p;
 165
 166 /* The list of directories to search after all the Go specific
 167    directories have been searched.  */
 168
 169 static vec<go_char_p> go_search_dirs;
 170
 171 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 172
 173 static bool
 174 go_langhook_handle_option (
 175     size_t scode,
 176     const char *arg,
 177     int value ATTRIBUTE_UNUSED,
 178     int kind ATTRIBUTE_UNUSED,
 179     location_t loc ATTRIBUTE_UNUSED,
 180     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 181 {
 182   enum opt_code code = (enum opt_code) scode;
 183   bool ret = true;
 184
 185   switch (code)
 186     {
 187     case OPT_I:
 188       go_add_search_path (arg);
 189       break;
 190
 191     case OPT_L:
 192       /* A -L option is assumed to come from the compiler driver.
 193          This is a system directory.  We search the following
 194          directories, if they exist, before this one:
 195            dir/go/VERSION
 196            dir/go/VERSION/MACHINE
 197          This is like include/c++.  */
 198       {
 199         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 200         size_t len;
 201         char *p;
 202         struct stat st;
 203
 204         len = strlen (arg);
 205         p = XALLOCAVEC (char,
 206                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 207                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 208         strcpy (p, arg);
 209         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 210           strcat (p, dir_separator_str);
 211         strcat (p, "go");
 212         strcat (p, dir_separator_str);
 213         strcat (p, DEFAULT_TARGET_VERSION);
 214         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 215           {
 216             go_add_search_path (p);
 217             strcat (p, dir_separator_str);
 218             strcat (p, DEFAULT_TARGET_MACHINE);
 219             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 220               go_add_search_path (p);
 221           }
 222
 223         /* Search ARG too, but only after we've searched to Go
 224            specific directories for all -L arguments.  */
 225         go_search_dirs.safe_push (arg);
 226       }
 227       break;
 228
 229     case OPT_fgo_dump_:
 230       ret = go_enable_dump (arg) ? true : false;
 231       break;
 232
 233     case OPT_fgo_optimize_:
 234       ret = go_enable_optimize (arg) ? true : false;
 235       break;
 236
 237     case OPT_fgo_pkgpath_:
 238       go_pkgpath = arg;
 239       break;
 240
 241     case OPT_fgo_prefix_:
 242       go_prefix = arg;
 243       break;
 244
 245     case OPT_fgo_relative_import_path_:
 246       go_relative_import_path = arg;
 247       break;
 248
 249     default:
 250       /* Just return 1 to indicate that the option is valid.  */
 251       break;
 252     }
 253
 254   return ret;
 255 }
 256
 257 /* Run after parsing options.  */
 258
 259 static bool
 260 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 261 {
 262   unsigned int ix;
 263   const char *dir;
 264
 265   gcc_assert (num_in_fnames > 0);
 266
 267   FOR_EACH_VEC_ELT (go_search_dirs, ix, dir)
 268     go_add_search_path (dir);
 269   go_search_dirs.release ();
 270
 271   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 272     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 273
 274   /* Tail call optimizations can confuse uses of runtime.Callers.  */
 275   if (!global_options_set.x_flag_optimize_sibling_calls)
 276     global_options.x_flag_optimize_sibling_calls = 0;
 277
 278   /* Returning false means that the backend should be used.  */
 279   return false;
 280 }
 281
 282 static void
 283 go_langhook_parse_file (void)
 284 {
 285   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 286                         go_require_return_statement);
 287 }
 288
 289 static tree
 290 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 291 {
 292   tree type;
 293   if (unsignedp)
 294     {
 295       if (bits == INT_TYPE_SIZE)
 296         type = unsigned_type_node;
 297       else if (bits == CHAR_TYPE_SIZE)
 298         type = unsigned_char_type_node;
 299       else if (bits == SHORT_TYPE_SIZE)
 300         type = short_unsigned_type_node;
 301       else if (bits == LONG_TYPE_SIZE)
 302         type = long_unsigned_type_node;
 303       else if (bits == LONG_LONG_TYPE_SIZE)
 304         type = long_long_unsigned_type_node;
 305       else
 306         type = make_unsigned_type(bits);
 307     }
 308   else
 309     {
 310       if (bits == INT_TYPE_SIZE)
 311         type = integer_type_node;
 312       else if (bits == CHAR_TYPE_SIZE)
 313         type = signed_char_type_node;
 314       else if (bits == SHORT_TYPE_SIZE)
 315         type = short_integer_type_node;
 316       else if (bits == LONG_TYPE_SIZE)
 317         type = long_integer_type_node;
 318       else if (bits == LONG_LONG_TYPE_SIZE)
 319         type = long_long_integer_type_node;
 320       else
 321         type = make_signed_type(bits);
 322     }
 323   return type;
 324 }
 325
 326 static tree
 327 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 328 {
 329   tree type;
 330   /* Go has no vector types.  Build them here.  FIXME: It does not
 331      make sense for the middle-end to ask the frontend for a type
 332      which the frontend does not support.  However, at least for now
 333      it is required.  See PR 46805.  */
 334   if (VECTOR_MODE_P (mode))
 335     {
 336       tree inner;
 337
 338       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 339       if (inner != NULL_TREE)
 340         return build_vector_type_for_mode (inner, mode);
 341       return NULL_TREE;
 342     }
 343
 344   // FIXME: This static_cast should be in machmode.h.
 345   enum mode_class mc = static_cast<enum mode_class>(GET_MODE_CLASS(mode));
 346   if (mc == MODE_INT)
 347     return go_langhook_type_for_size(GET_MODE_BITSIZE(mode), unsignedp);
 348   else if (mc == MODE_FLOAT)
 349     {
 350       switch (GET_MODE_BITSIZE (mode))
 351         {
 352         case 32:
 353           return float_type_node;
 354         case 64:
 355           return double_type_node;
 356         default:
 357           // We have to check for long double in order to support
 358           // i386 excess precision.
 359           if (mode == TYPE_MODE(long_double_type_node))
 360             return long_double_type_node;
 361         }
 362     }
 363   else if (mc == MODE_COMPLEX_FLOAT)
 364     {
 365       switch (GET_MODE_BITSIZE (mode))
 366         {
 367         case 64:
 368           return complex_float_type_node;
 369         case 128:
 370           return complex_double_type_node;
 371         default:
 372           // We have to check for long double in order to support
 373           // i386 excess precision.
 374           if (mode == TYPE_MODE(complex_long_double_type_node))
 375             return complex_long_double_type_node;
 376         }
 377     }
 378
 379 #if HOST_BITS_PER_WIDE_INT >= 64
 380   /* The middle-end and some backends rely on TImode being supported
 381      for 64-bit HWI.  */
 382   if (mode == TImode)
 383     {
 384       type = build_nonstandard_integer_type (GET_MODE_BITSIZE (TImode),
 385                                              unsignedp);
 386       if (type && TYPE_MODE (type) == TImode)
 387         return type;
 388     }
 389 #endif
 390   return NULL_TREE;
 391 }
 392
 393 /* Record a builtin function.  We just ignore builtin functions.  */
 394
 395 static tree
 396 go_langhook_builtin_function (tree decl)
 397 {
 398   return decl;
 399 }
 400
 401 /* Return true if we are in the global binding level.  */
 402
 403 static bool
 404 go_langhook_global_bindings_p (void)
 405 {
 406   return current_function_decl == NULL_TREE;
 407 }
 408
 409 /* Push a declaration into the current binding level.  We can't
 410    usefully implement this since we don't want to convert from tree
 411    back to one of our internal data structures.  I think the only way
 412    this is used is to record a decl which is to be returned by
 413    getdecls, and we could implement it for that purpose if
 414    necessary.  */
 415
 416 static tree
 417 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 418 {
 419   gcc_unreachable ();
 420 }
 421
 422 /* This hook is used to get the current list of declarations as trees.
 423    We don't support that; instead we use the write_globals hook.  This
 424    can't simply crash because it is called by -gstabs.  */
 425
 426 static tree
 427 go_langhook_getdecls (void)
 428 {
 429   return NULL;
 430 }
 431
 432 /* Write out globals.  */
 433
 434 static void
 435 go_langhook_write_globals (void)
 436 {
 437   go_write_globals ();
 438 }
 439
 440 /* Go specific gimplification.  We need to gimplify
 441    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 442    it.  */
 443
 444 static int
 445 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 446 {
 447   if (TREE_CODE (*expr_p) == CALL_EXPR
 448       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 449     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 450                    is_gimple_val, fb_rvalue);
 451   return GS_UNHANDLED;
 452 }
 453
 454 /* Return a decl for the exception personality function.  The function
 455    itself is implemented in libgo/runtime/go-unwind.c.  */
 456
 457 static tree
 458 go_langhook_eh_personality (void)
 459 {
 460   static tree personality_decl;
 461   if (personality_decl == NULL_TREE)
 462     {
 463       personality_decl = build_personality_function ("gccgo");
 464       go_preserve_from_gc (personality_decl);
 465     }
 466   return personality_decl;
 467 }
 468
 469 /* Functions called directly by the generic backend.  */
 470
 471 tree
 472 convert (tree type, tree expr)
 473 {
 474   if (type == error_mark_node
 475       || expr == error_mark_node
 476       || TREE_TYPE (expr) == error_mark_node)
 477     return error_mark_node;
 478
 479   if (type == TREE_TYPE (expr))
 480     return expr;
 481
 482   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 483     return fold_convert (type, expr);
 484
 485   switch (TREE_CODE (type))
 486     {
 487     case VOID_TYPE:
 488     case BOOLEAN_TYPE:
 489       return fold_convert (type, expr);
 490     case INTEGER_TYPE:
 491       return fold (convert_to_integer (type, expr));
 492     case POINTER_TYPE:
 493       return fold (convert_to_pointer (type, expr));
 494     case REAL_TYPE:
 495       return fold (convert_to_real (type, expr));
 496     case COMPLEX_TYPE:
 497       return fold (convert_to_complex (type, expr));
 498     default:
 499       break;
 500     }
 501
 502   gcc_unreachable ();
 503 }
 504
 505 /* FIXME: This is a hack to preserve trees that we create from the
 506    garbage collector.  */
 507
 508 static GTY(()) tree go_gc_root;
 509
 510 void
 511 go_preserve_from_gc (tree t)
 512 {
 513   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 514 }
 515
 516 /* Convert an identifier for use in an error message.  */
 517
 518 const char *
 519 go_localize_identifier (const char *ident)
 520 {
 521   return identifier_to_locale (ident);
 522 }
 523
 524 #undef LANG_HOOKS_NAME
 525 #undef LANG_HOOKS_INIT
 526 #undef LANG_HOOKS_OPTION_LANG_MASK
 527 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 528 #undef LANG_HOOKS_HANDLE_OPTION
 529 #undef LANG_HOOKS_POST_OPTIONS
 530 #undef LANG_HOOKS_PARSE_FILE
 531 #undef LANG_HOOKS_TYPE_FOR_MODE
 532 #undef LANG_HOOKS_TYPE_FOR_SIZE
 533 #undef LANG_HOOKS_BUILTIN_FUNCTION
 534 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 535 #undef LANG_HOOKS_PUSHDECL
 536 #undef LANG_HOOKS_GETDECLS
 537 #undef LANG_HOOKS_WRITE_GLOBALS
 538 #undef LANG_HOOKS_GIMPLIFY_EXPR
 539 #undef LANG_HOOKS_EH_PERSONALITY
 540
 541 #define LANG_HOOKS_NAME                 "GNU Go"
 542 #define LANG_HOOKS_INIT                 go_langhook_init
 543 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 544 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 545 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 546 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 547 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 548 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 549 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 550 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 551 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 552 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 553 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 554 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 555 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 556 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 557
 558 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 559
 560 #include "gt-go-go-lang.h"
 561 #include "gtype-go.h"