gcc/go/go-lang.c

   1 /* go-lang.c -- Go frontend gcc interface.
   2    Copyright (C) 2009, 2010 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, FLOAT_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
 153   /* By default assume that floating point math does not trap.  */
 154   opts->x_flag_trapping_math = 0;
 155
 156   /* We turn on stack splitting if we can.  */
 157   if (targetm.supports_split_stack (false, opts))
 158     opts->x_flag_split_stack = 1;
 159
 160   /* Exceptions are used to handle recovering from panics.  */
 161   opts->x_flag_exceptions = 1;
 162   opts->x_flag_non_call_exceptions = 1;
 163 }
 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     case OPT_L:
 183       /* For the compiler, we currently handle -I and -L exactly the
 184          same way: they give us a directory to search for import
 185          statements.  */
 186       go_add_search_path (arg);
 187       break;
 188
 189     case OPT_fgo_dump_:
 190       ret = go_enable_dump (arg) ? true : false;
 191       break;
 192
 193     case OPT_fgo_prefix_:
 194       go_set_prefix (arg);
 195       break;
 196
 197     default:
 198       /* Just return 1 to indicate that the option is valid.  */
 199       break;
 200     }
 201
 202   return ret;
 203 }
 204
 205 /* Run after parsing options.  */
 206
 207 static bool
 208 go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
 209 {
 210   gcc_assert (num_in_fnames > 0);
 211
 212   if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
 213     flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
 214
 215   /* Returning false means that the backend should be used.  */
 216   return false;
 217 }
 218
 219 static void
 220 go_langhook_parse_file (void)
 221 {
 222   go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
 223                         go_require_return_statement);
 224 }
 225
 226 static tree
 227 go_langhook_type_for_size (unsigned int bits, int unsignedp)
 228 {
 229   return go_type_for_size (bits, unsignedp);
 230 }
 231
 232 static tree
 233 go_langhook_type_for_mode (enum machine_mode mode, int unsignedp)
 234 {
 235   return go_type_for_mode (mode, unsignedp);
 236 }
 237
 238 /* Record a builtin function.  We just ignore builtin functions.  */
 239
 240 static tree
 241 go_langhook_builtin_function (tree decl)
 242 {
 243   return decl;
 244 }
 245
 246 static int
 247 go_langhook_global_bindings_p (void)
 248 {
 249   return current_function_decl == NULL ? 1 : 0;
 250 }
 251
 252 /* Push a declaration into the current binding level.  We can't
 253    usefully implement this since we don't want to convert from tree
 254    back to one of our internal data structures.  I think the only way
 255    this is used is to record a decl which is to be returned by
 256    getdecls, and we could implement it for that purpose if
 257    necessary.  */
 258
 259 static tree
 260 go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
 261 {
 262   gcc_unreachable ();
 263 }
 264
 265 /* This hook is used to get the current list of declarations as trees.
 266    We don't support that; instead we use the write_globals hook.  This
 267    can't simply crash because it is called by -gstabs.  */
 268
 269 static tree
 270 go_langhook_getdecls (void)
 271 {
 272   return NULL;
 273 }
 274
 275 /* Write out globals.  */
 276
 277 static void
 278 go_langhook_write_globals (void)
 279 {
 280   go_write_globals ();
 281 }
 282
 283 /* Go specific gimplification.  We need to gimplify
 284    CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
 285    it.  */
 286
 287 static int
 288 go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 289 {
 290   if (TREE_CODE (*expr_p) == CALL_EXPR
 291       && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
 292     gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
 293                    is_gimple_val, fb_rvalue);
 294   return GS_UNHANDLED;
 295 }
 296
 297 /* Return a decl for the exception personality function.  The function
 298    itself is implemented in libgo/runtime/go-unwind.c.  */
 299
 300 static tree
 301 go_langhook_eh_personality (void)
 302 {
 303   static tree personality_decl;
 304   if (personality_decl == NULL_TREE)
 305     {
 306       personality_decl = build_personality_function ("gccgo");
 307       go_preserve_from_gc (personality_decl);
 308     }
 309   return personality_decl;
 310 }
 311
 312 /* Functions called directly by the generic backend.  */
 313
 314 tree
 315 convert (tree type, tree expr)
 316 {
 317   if (type == error_mark_node
 318       || expr == error_mark_node
 319       || TREE_TYPE (expr) == error_mark_node)
 320     return error_mark_node;
 321
 322   if (type == TREE_TYPE (expr))
 323     return expr;
 324
 325   if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
 326     return fold_convert (type, expr);
 327
 328   switch (TREE_CODE (type))
 329     {
 330     case VOID_TYPE:
 331     case BOOLEAN_TYPE:
 332       return fold_convert (type, expr);
 333     case INTEGER_TYPE:
 334       return fold (convert_to_integer (type, expr));
 335     case POINTER_TYPE:
 336       return fold (convert_to_pointer (type, expr));
 337     case REAL_TYPE:
 338       return fold (convert_to_real (type, expr));
 339     case COMPLEX_TYPE:
 340       return fold (convert_to_complex (type, expr));
 341     default:
 342       break;
 343     }
 344
 345   gcc_unreachable ();
 346 }
 347
 348 /* FIXME: This is a hack to preserve trees that we create from the
 349    garbage collector.  */
 350
 351 static GTY(()) tree go_gc_root;
 352
 353 void
 354 go_preserve_from_gc (tree t)
 355 {
 356   go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
 357 }
 358
 359 /* Convert an identifier for use in an error message.  */
 360
 361 const char *
 362 go_localize_identifier (const char *ident)
 363 {
 364   return identifier_to_locale (ident);
 365 }
 366
 367 #undef LANG_HOOKS_NAME
 368 #undef LANG_HOOKS_INIT
 369 #undef LANG_HOOKS_OPTION_LANG_MASK
 370 #undef LANG_HOOKS_INIT_OPTIONS_STRUCT
 371 #undef LANG_HOOKS_HANDLE_OPTION
 372 #undef LANG_HOOKS_POST_OPTIONS
 373 #undef LANG_HOOKS_PARSE_FILE
 374 #undef LANG_HOOKS_TYPE_FOR_MODE
 375 #undef LANG_HOOKS_TYPE_FOR_SIZE
 376 #undef LANG_HOOKS_BUILTIN_FUNCTION
 377 #undef LANG_HOOKS_GLOBAL_BINDINGS_P
 378 #undef LANG_HOOKS_PUSHDECL
 379 #undef LANG_HOOKS_GETDECLS
 380 #undef LANG_HOOKS_WRITE_GLOBALS
 381 #undef LANG_HOOKS_GIMPLIFY_EXPR
 382 #undef LANG_HOOKS_EH_PERSONALITY
 383
 384 #define LANG_HOOKS_NAME                 "GNU Go"
 385 #define LANG_HOOKS_INIT                 go_langhook_init
 386 #define LANG_HOOKS_OPTION_LANG_MASK     go_langhook_option_lang_mask
 387 #define LANG_HOOKS_INIT_OPTIONS_STRUCT  go_langhook_init_options_struct
 388 #define LANG_HOOKS_HANDLE_OPTION        go_langhook_handle_option
 389 #define LANG_HOOKS_POST_OPTIONS         go_langhook_post_options
 390 #define LANG_HOOKS_PARSE_FILE           go_langhook_parse_file
 391 #define LANG_HOOKS_TYPE_FOR_MODE        go_langhook_type_for_mode
 392 #define LANG_HOOKS_TYPE_FOR_SIZE        go_langhook_type_for_size
 393 #define LANG_HOOKS_BUILTIN_FUNCTION     go_langhook_builtin_function
 394 #define LANG_HOOKS_GLOBAL_BINDINGS_P    go_langhook_global_bindings_p
 395 #define LANG_HOOKS_PUSHDECL             go_langhook_pushdecl
 396 #define LANG_HOOKS_GETDECLS             go_langhook_getdecls
 397 #define LANG_HOOKS_WRITE_GLOBALS        go_langhook_write_globals
 398 #define LANG_HOOKS_GIMPLIFY_EXPR        go_langhook_gimplify_expr
 399 #define LANG_HOOKS_EH_PERSONALITY       go_langhook_eh_personality
 400
 401 struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 402
 403 #include "gt-go-go-lang.h"
 404 #include "gtype-go.h"