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 "vec.h"
  27 #include "hashtab.h"
  28 #include "hash-set.h"
  29 #include "machmode.h"
  30 #include "tm.h"
  31 #include "hard-reg-set.h"
  32 #include "input.h"
  33 #include "function.h"
  34 #include "gimple-expr.h"
  35 #include "gimplify.h"
  36 #include "stor-layout.h"
  37 #include "toplev.h"
  38 #include "debug.h"
  39 #include "options.h"
  40 #include "flags.h"
  41 #include "convert.h"
  42 #include "diagnostic.h"
  43 #include "langhooks.h"
  44 #include "langhooks-def.h"
  45 #include "target.h"
  46 #include "common/common-target.h"
  47
  48 #include <mpfr.h>
  49
  50 #include "go-c.h"
  51
  52 /* Language-dependent contents of a type.  */
  53
  54 struct GTY(()) lang_type
  55 {
  56   char dummy;
  57 };
  58
  59 /* Language-dependent contents of a decl.  */
  60
  61 struct GTY(()) lang_decl
  62 {
  63   char dummy;
  64 };
  65
  66 /* Language-dependent contents of an identifier.  This must include a
  67    tree_identifier.  */
  68
  69 struct GTY(()) lang_identifier
  70 {
  71   struct tree_identifier common;
  72 };
  73
  74 /* The resulting tree type.  */
  75
  76 union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
  77            chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
  78 lang_tree_node
  79 {
  80   union tree_node GTY((tag ("0"),
  81                        desc ("tree_node_structure (&%h)"))) generic;
  82   struct lang_identifier GTY((tag ("1"))) identifier;
  83 };
  84
  85 /* We don't use language_function.  */
  86
  87 struct GTY(()) language_function
  88 {
  89   int dummy;
  90 };
  91
  92 /* Option information we need to pass to go_create_gogo.  */
  93
  94 static const char *go_pkgpath = NULL;
  95 static const char *go_prefix = NULL;
  96 static const char *go_relative_import_path = NULL;
  97
  98 /* Language hooks.  */
  99
 100 static bool
 101 go_langhook_init (void)
 102 {
 103   build_common_tree_nodes (false, false);
 104
 105   /* I don't know why this has to be done explicitly.  */
 106   void_list_node = build_tree_list (NULL_TREE, void_type_node);
 107
 108   /* We must create the gogo IR after calling build_common_tree_nodes
 109      (because Gogo::define_builtin_function_trees refers indirectly
 110      to, e.g., unsigned_char_type_node) but before calling
 111      build_common_builtin_nodes (because it calls, indirectly,
 112      go_type_for_size).  */
 113   go_create_gogo (INT_TYPE_SIZE, POINTER_SIZE, go_pkgpath, go_prefix,
 114                   go_relative_import_path, go_check_divide_zero,
 115                   go_check_divide_overflow);
 116
 117   build_common_builtin_nodes ();
 118
 119   /* The default precision for floating point numbers.  This is used
 120      for floating point constants with abstract type.  This may
 121      eventually be controllable by a command line option.  */
 122   mpfr_set_default_prec (256);
 123
 124   /* Go uses exceptions.  */
 125   using_eh_for_cleanups ();
 126
 127   return true;
 128 }
 129
 130 /* The option mask.  */
 131
 132 static unsigned int
 133 go_langhook_option_lang_mask (void)
 134 {
 135   return CL_Go;
 136 }
 137
 138 /* Initialize the options structure.  */
 139
 140 static void
 141 go_langhook_init_options_struct (struct gcc_options *opts)
 142 {
 143   /* Go says that signed overflow is precisely defined.  */
 144   opts->x_flag_wrapv = 1;
 145
 146   /* We default to using strict aliasing, since Go pointers are safe.
 147      This is turned off for code that imports the "unsafe" package,
 148      because using unsafe.pointer violates C style aliasing
 149      requirements.  */
 150   opts->x_flag_strict_aliasing = 1;
 151
 152   /* Default to avoiding range issues for complex multiply and
 153      divide.  */
 154   opts->x_flag_complex_method = 2;
 155
 156   /* The builtin math functions should not set errno.  */
 157   opts->x_flag_errno_math = 0;
 158   opts->frontend_set_flag_errno_math = true;
 159
 160   /* We turn on stack splitting if we can.  */
 161   if (targetm_common.supports_split_stack (false, opts))
 162     opts->x_flag_split_stack = 1;
 163
 164   /* Exceptions are used to handle recovering from panics.  */
 165   opts->x_flag_exceptions = 1;
 166   opts->x_flag_non_call_exceptions = 1;
 167 }
 168
 169 /* Infrastructure for a vector of char * pointers.  */
 170
 171 typedef const char *go_char_p;
 172
 173 /* The list of directories to search after all the Go specific
 174    directories have been searched.  */
 175
 176 static vec<go_char_p> go_search_dirs;
 177
 178 /* Handle Go specific options.  Return 0 if we didn't do anything.  */
 179
 180 static bool
 181 go_langhook_handle_option (
 182     size_t scode,
 183     const char *arg,
 184     int value ATTRIBUTE_UNUSED,
 185     int kind ATTRIBUTE_UNUSED,
 186     location_t loc ATTRIBUTE_UNUSED,
 187     const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
 188 {
 189   enum opt_code code = (enum opt_code) scode;
 190   bool ret = true;
 191
 192   switch (code)
 193     {
 194     case OPT_I:
 195       go_add_search_path (arg);
 196       break;
 197
 198     case OPT_L:
 199       /* A -L option is assumed to come from the compiler driver.
 200          This is a system directory.  We search the following
 201          directories, if they exist, before this one:
 202            dir/go/VERSION
 203            dir/go/VERSION/MACHINE
 204          This is like include/c++.  */
 205       {
 206         static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
 207         size_t len;
 208         char *p;
 209         struct stat st;
 210
 211         len = strlen (arg);
 212         p = XALLOCAVEC (char,
 213                         (len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
 214                          + sizeof DEFAULT_TARGET_MACHINE + 3));
 215         strcpy (p, arg);
 216         if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
 217           strcat (p, dir_separator_str);
 218         strcat (p, "go");
 219         strcat (p, dir_separator_str);
 220         strcat (p, DEFAULT_TARGET_VERSION);
 221         if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 222           {
 223             go_add_search_path (p);
 224             strcat (p, dir_separator_str);
 225             strcat (p, DEFAULT_TARGET_MACHINE);
 226             if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
 227               go_add_search_path (p);
 228           }
 229
 230         /* Search ARG too, but only after we've searched to Go
 231            specific directories for all -L arguments.  */
 232         go_search_dirs.safe_push (arg);
 233       }
 234       break;
 235
 236     case OPT_fgo_dump_:
 237       ret = go_enable_dump (arg) ? true : false;
 238       break;
 239
 240     case OPT_fgo_optimize_:
 241       ret = go_enable_optimize (arg) ? true : false;
 242       break;
 243
 244     case OPT_fgo_pkgpath_:
 245       go_pkgpath = arg;
 246       break;
 247
 248     case OPT_fgo_prefix_:
 249       go_prefix = arg;
 250       break;
 251
 252     case OPT_fgo_relative_import_path_:
 253       go_relative_import_path = arg;
 254       break;
 255
 256     default:
 257       /* Just return 1 to indicate that the option is valid.  */
 258       break;
 259     }
 260
 261   return ret;
 262 }
 263
 264 /* Run after parsing options.  */
 265
 266 static bool
 267 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 268 {
 269   unsigned int ix;
 270   const char *dir;
 271
 272   gcc_assert (num_in_fnames > 0);
 273
 274   FOR_EACH_VEC_ELT (go_search_dirs, ix, dir)
 275     go_add_search_path (dir);
 276   go_search_dirs.release ();
 277
 278   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 279     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 280
 281   /* Tail call optimizations can confuse uses of runtime.Callers.  */
 282   if (!global_options_set.x_flag_optimize_sibling_calls)
 283     global_options.x_flag_optimize_sibling_calls = 0;
 284
 285   /* Returning false means that the backend should be used.  */
 286   return false;
 287 }
 288
 289 static void
 290 go_langhook_parse_file (void)
 291 {
 292   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 293                         go_require_return_statement);
 294 }
 295
 296 static tree
 297 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 298 {
 299   tree type;
 300   if (unsignedp)
 301     {
 302       if (bits == INT_TYPE_SIZE)
 303         type = unsigned_type_node;
 304       else if (bits == CHAR_TYPE_SIZE)
 305         type = unsigned_char_type_node;
 306       else if (bits == SHORT_TYPE_SIZE)
 307         type = short_unsigned_type_node;
 308       else if (bits == LONG_TYPE_SIZE)
 309         type = long_unsigned_type_node;
 310       else if (bits == LONG_LONG_TYPE_SIZE)
 311         type = long_long_unsigned_type_node;
 312       else
 313         type = make_unsigned_type(bits);
 314     }
 315   else
 316     {
 317       if (bits == INT_TYPE_SIZE)
 318         type = integer_type_node;
 319       else if (bits == CHAR_TYPE_SIZE)
 320         type = signed_char_type_node;
 321       else if (bits == SHORT_TYPE_SIZE)
 322         type = short_integer_type_node;
 323       else if (bits == LONG_TYPE_SIZE)
 324         type = long_integer_type_node;
 325       else if (bits == LONG_LONG_TYPE_SIZE)
 326         type = long_long_integer_type_node;
 327       else
 328         type = make_signed_type(bits);
 329     }
 330   return type;
 331 }
 332
 333 static tree
 334 go_langhook_type_for_mode (machine_mode mode, int unsignedp)
 335 {
 336   tree type;
 337   /* Go has no vector types.  Build them here.  FIXME: It does not
 338      make sense for the middle-end to ask the frontend for a type
 339      which the frontend does not support.  However, at least for now
 340      it is required.  See PR 46805.  */
 341   if (VECTOR_MODE_P (mode))
 342     {
 343       tree inner;
 344
 345       inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
 346       if (inner != NULL_TREE)
 347         return build_vector_type_for_mode (inner, mode);
 348       return NULL_TREE;
 349     }
 350
 351   // FIXME: This static_cast should be in machmode.h.
 352   enum mode_class mc = static_cast<enum mode_class>(GET_MODE_CLASS(mode));
 353   if (mc == MODE_INT)
 354     return go_langhook_type_for_size(GET_MODE_BITSIZE(mode), unsignedp);
 355   else if (mc == MODE_FLOAT)
 356     {
 357       switch (GET_MODE_BITSIZE (mode))
 358         {
 359         case 32:
 360           return float_type_node;
 361         case 64:
 362           return double_type_node;
 363         default:
 364           // We have to check for long double in order to support
 365           // i386 excess precision.
 366           if (mode == TYPE_MODE(long_double_type_node))
 367             return long_double_type_node;
 368         }
 369     }
 370   else if (mc == MODE_COMPLEX_FLOAT)
 371     {
 372       switch (GET_MODE_BITSIZE (mode))
 373         {
 374         case 64:
 375           return complex_float_type_node;
 376         case 128:
 377           return complex_double_type_node;
 378         default:
 379           // We have to check for long double in order to support
 380           // i386 excess precision.
 381           if (mode == TYPE_MODE(complex_long_double_type_node))
 382             return complex_long_double_type_node;
 383         }
 384     }
 385
 386 #if HOST_BITS_PER_WIDE_INT >= 64
 387   /* The middle-end and some backends rely on TImode being supported
 388      for 64-bit HWI.  */
 389   if (mode == TImode)
 390     {
 391       type = build_nonstandard_integer_type (GET_MODE_BITSIZE (TImode),
 392                                              unsignedp);
 393       if (type && TYPE_MODE (type) == TImode)
 394         return type;
 395     }
 396 #endif
 397   return NULL_TREE;
 398 }
 399
 400 /* Record a builtin function.  We just ignore builtin functions.  */
 401
 402 static tree
 403 go_langhook_builtin_function (tree decl)
 404 {
 405   return decl;
 406 }
 407
 408 /* Return true if we are in the global binding level.  */
 409
 410 static bool
 411 go_langhook_global_bindings_p (void)
 412 {
 413   return current_function_decl == NULL_TREE;
 414 }
 415
 416 /* Push a declaration into the current binding level.  We can't
 417    usefully implement this since we don't want to convert from tree
 418    back to one of our internal data structures.  I think the only way
 419    this is used is to record a decl which is to be returned by
 420    getdecls, and we could implement it for that purpose if
 421    necessary.  */
 422
 423 static tree
 424 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 425 {
 426   gcc_unreachable ();
 427 }
 428
 429 /* This hook is used to get the current list of declarations as trees.
 430    We don't support that; instead we use the write_globals hook.  This
 431    can't simply crash because it is called by -gstabs.  */
 432
 433 static tree
 434 go_langhook_getdecls (void)
 435 {
 436   return NULL;
 437 }
 438
 439 /* Write out globals.  */
 440
 441 static void
 442 go_langhook_write_globals (void)
 443 {
 444   go_write_globals ();
 445 }
 446
 447 /* Go specific gimplification.  We need to gimplify
 448    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 449    it.  */
 450
 451 static int
 452 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 453 {
 454   if (TREE_CODE (*expr_p) == CALL_EXPR
 455       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 456     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 457                    is_gimple_val, fb_rvalue);
 458   return GS_UNHANDLED;
 459 }
 460
 461 /* Return a decl for the exception personality function.  The function
 462    itself is implemented in libgo/runtime/go-unwind.c.  */
 463
 464 static tree
 465 go_langhook_eh_personality (void)
 466 {
 467   static tree personality_decl;
 468   if (personality_decl == NULL_TREE)
 469     {
 470       personality_decl = build_personality_function ("gccgo");
 471       go_preserve_from_gc (personality_decl);
 472     }
 473   return personality_decl;
 474 }
 475
 476 /* Functions called directly by the generic backend.  */
 477
 478 tree
 479 convert (tree type, tree expr)
 480 {
 481   if (type == error_mark_node
 482       || expr == error_mark_node
 483       || TREE_TYPE (expr) == error_mark_node)
 484     return error_mark_node;
 485
 486   if (type == TREE_TYPE (expr))
 487     return expr;
 488
 489   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 490     return fold_convert (type, expr);
 491
 492   switch (TREE_CODE (type))
 493     {
 494     case VOID_TYPE:
 495     case BOOLEAN_TYPE:
 496       return fold_convert (type, expr);
 497     case INTEGER_TYPE:
 498       return fold (convert_to_integer (type, expr));
 499     case POINTER_TYPE:
 500       return fold (convert_to_pointer (type, expr));
 501     case REAL_TYPE:
 502       return fold (convert_to_real (type, expr));
 503     case COMPLEX_TYPE:
 504       return fold (convert_to_complex (type, expr));
 505     default:
 506       break;
 507     }
 508
 509   gcc_unreachable ();
 510 }
 511
 512 /* FIXME: This is a hack to preserve trees that we create from the
 513    garbage collector.  */
 514
 515 static GTY(()) tree go_gc_root;
 516
 517 void
 518 go_preserve_from_gc (tree t)
 519 {
 520   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 521 }
 522
 523 /* Convert an identifier for use in an error message.  */
 524
 525 const char *
 526 go_localize_identifier (const char *ident)
 527 {
 528   return identifier_to_locale (ident);
 529 }
 530
 531 #undef LANG_HOOKS_NAME
 532 #undef LANG_HOOKS_INIT
 533 #undef LANG_HOOKS_OPTION_LANG_MASK
 534 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 535 #undef LANG_HOOKS_HANDLE_OPTION
 536 #undef LANG_HOOKS_POST_OPTIONS
 537 #undef LANG_HOOKS_PARSE_FILE
 538 #undef LANG_HOOKS_TYPE_FOR_MODE
 539 #undef LANG_HOOKS_TYPE_FOR_SIZE
 540 #undef LANG_HOOKS_BUILTIN_FUNCTION
 541 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 542 #undef LANG_HOOKS_PUSHDECL
 543 #undef LANG_HOOKS_GETDECLS
 544 #undef LANG_HOOKS_WRITE_GLOBALS
 545 #undef LANG_HOOKS_GIMPLIFY_EXPR
 546 #undef LANG_HOOKS_EH_PERSONALITY
 547
 548 #define LANG_HOOKS_NAME                 "GNU Go"
 549 #define LANG_HOOKS_INIT                 go_langhook_init
 550 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 551 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 552 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 553 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 554 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 555 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 556 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 557 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 558 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 559 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 560 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 561 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 562 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 563 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 564
 565 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 566
 567 #include "gt-go-go-lang.h"
 568 #include "gtype-go.h"