langhooks.c revision 117395
1/* Default language-specific hooks. 2 Copyright 2001, 2002 Free Software Foundation, Inc. 3 Contributed by Alexandre Oliva <aoliva@redhat.com> 4 5This file is part of GNU CC. 6 7GNU CC is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 2, or (at your option) 10any later version. 11 12GNU CC is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17You should have received a copy of the GNU General Public License 18along with GNU CC; see the file COPYING. If not, write to 19the Free Software Foundation, 59 Temple Place - Suite 330, 20Boston, MA 02111-1307, USA. */ 21 22#include "config.h" 23#include "system.h" 24#include "toplev.h" 25#include "tree.h" 26#include "c-tree.h" 27#include "tree-inline.h" 28#include "rtl.h" 29#include "insn-config.h" 30#include "integrate.h" 31#include "flags.h" 32#include "langhooks.h" 33#include "langhooks-def.h" 34 35/* Do nothing; in many cases the default hook. */ 36 37void 38lhd_do_nothing () 39{ 40} 41 42/* Do nothing (tree). */ 43 44void 45lhd_do_nothing_t (t) 46 tree t ATTRIBUTE_UNUSED; 47{ 48} 49 50/* Do nothing (int). */ 51 52void 53lhd_do_nothing_i (i) 54 int i ATTRIBUTE_UNUSED; 55{ 56} 57 58/* Do nothing (function). */ 59 60void 61lhd_do_nothing_f (f) 62 struct function *f ATTRIBUTE_UNUSED; 63{ 64} 65 66/* Do nothing (return the tree node passed). */ 67 68tree 69lhd_return_tree (t) 70 tree t; 71{ 72 return t; 73} 74 75/* Do nothing (return NULL_TREE). */ 76 77tree 78lhd_return_null_tree (t) 79 tree t ATTRIBUTE_UNUSED; 80{ 81 return NULL_TREE; 82} 83 84/* Do nothing; the default hook to decode an option. */ 85 86int 87lhd_decode_option (argc, argv) 88 int argc ATTRIBUTE_UNUSED; 89 char **argv ATTRIBUTE_UNUSED; 90{ 91 return 0; 92} 93 94/* Called from by print-tree.c. */ 95 96void 97lhd_print_tree_nothing (file, node, indent) 98 FILE *file ATTRIBUTE_UNUSED; 99 tree node ATTRIBUTE_UNUSED; 100 int indent ATTRIBUTE_UNUSED; 101{ 102} 103 104/* Called from safe_from_p. */ 105 106int 107lhd_safe_from_p (x, exp) 108 rtx x ATTRIBUTE_UNUSED; 109 tree exp ATTRIBUTE_UNUSED; 110{ 111 return 1; 112} 113 114/* Called from unsafe_for_reeval. */ 115 116int 117lhd_unsafe_for_reeval (t) 118 tree t ATTRIBUTE_UNUSED; 119{ 120 return -1; 121} 122 123/* Called from staticp. */ 124 125int 126lhd_staticp (exp) 127 tree exp ATTRIBUTE_UNUSED; 128{ 129 return 0; 130} 131 132/* Called from check_global_declarations. */ 133 134bool 135lhd_warn_unused_global_decl (decl) 136 tree decl; 137{ 138 /* This is what used to exist in check_global_declarations. Probably 139 not many of these actually apply to non-C languages. */ 140 141 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl)) 142 return false; 143 if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl)) 144 return false; 145 if (DECL_IN_SYSTEM_HEADER (decl)) 146 return false; 147 148 return true; 149} 150 151/* Set the DECL_ASSEMBLER_NAME for DECL. */ 152void 153lhd_set_decl_assembler_name (decl) 154 tree decl; 155{ 156 /* The language-independent code should never use the 157 DECL_ASSEMBLER_NAME for lots of DECLs. Only FUNCTION_DECLs and 158 VAR_DECLs for variables with static storage duration need a real 159 DECL_ASSEMBLER_NAME. */ 160 if (TREE_CODE (decl) == FUNCTION_DECL 161 || (TREE_CODE (decl) == VAR_DECL 162 && (TREE_STATIC (decl) 163 || DECL_EXTERNAL (decl) 164 || TREE_PUBLIC (decl)))) 165 /* By default, assume the name to use in assembly code is the 166 same as that used in the source language. (That's correct 167 for C, and GCC used to set DECL_ASSEMBLER_NAME to the same 168 value as DECL_NAME in build_decl, so this choice provides 169 backwards compatibility with existing front-ends. */ 170 SET_DECL_ASSEMBLER_NAME (decl, DECL_NAME (decl)); 171 else 172 /* Nobody should ever be asking for the DECL_ASSEMBLER_NAME of 173 these DECLs -- unless they're in language-dependent code, in 174 which case set_decl_assembler_name hook should handle things. */ 175 abort (); 176} 177 178/* By default we always allow bit-field based optimizations. */ 179bool 180lhd_can_use_bit_fields_p () 181{ 182 return true; 183} 184 185/* Provide a default routine to clear the binding stack. This is used 186 by languages that don't need to do anything special. */ 187void 188lhd_clear_binding_stack () 189{ 190 while (! (*lang_hooks.decls.global_bindings_p) ()) 191 poplevel (0, 0, 0); 192} 193 194/* Type promotion for variable arguments. */ 195tree 196lhd_type_promotes_to (type) 197 tree type ATTRIBUTE_UNUSED; 198{ 199 abort (); 200} 201 202/* Invalid use of an incomplete type. */ 203void 204lhd_incomplete_type_error (value, type) 205 tree value ATTRIBUTE_UNUSED, type; 206{ 207 if (TREE_CODE (type) == ERROR_MARK) 208 return; 209 210 abort (); 211} 212 213/* Provide a default routine for alias sets that always returns -1. This 214 is used by languages that don't need to do anything special. */ 215 216HOST_WIDE_INT 217lhd_get_alias_set (t) 218 tree t ATTRIBUTE_UNUSED; 219{ 220 return -1; 221} 222 223/* Provide a hook routine for alias sets that always returns 0. This is 224 used by languages that haven't deal with alias sets yet. */ 225 226HOST_WIDE_INT 227hook_get_alias_set_0 (t) 228 tree t ATTRIBUTE_UNUSED; 229{ 230 return 0; 231} 232 233/* This is the default expand_expr function. */ 234 235rtx 236lhd_expand_expr (t, r, mm, em) 237 tree t ATTRIBUTE_UNUSED; 238 rtx r ATTRIBUTE_UNUSED; 239 enum machine_mode mm ATTRIBUTE_UNUSED; 240 int em ATTRIBUTE_UNUSED; 241{ 242 abort (); 243} 244 245/* This is the default decl_printable_name function. */ 246 247const char * 248lhd_decl_printable_name (decl, verbosity) 249 tree decl; 250 int verbosity ATTRIBUTE_UNUSED; 251{ 252 return IDENTIFIER_POINTER (DECL_NAME (decl)); 253} 254 255/* lang_hooks.tree_inlining.walk_subtrees is called by walk_tree() 256 after handling common cases, but before walking code-specific 257 sub-trees. If this hook is overridden for a language, it should 258 handle language-specific tree codes, as well as language-specific 259 information associated to common tree codes. If a tree node is 260 completely handled within this function, it should set *SUBTREES to 261 0, so that generic handling isn't attempted. For language-specific 262 tree codes, generic handling would abort(), so make sure it is set 263 properly. Both SUBTREES and *SUBTREES is guaranteed to be nonzero 264 when the function is called. */ 265 266tree 267lhd_tree_inlining_walk_subtrees (tp,subtrees,func,data,htab) 268 tree *tp ATTRIBUTE_UNUSED; 269 int *subtrees ATTRIBUTE_UNUSED; 270 walk_tree_fn func ATTRIBUTE_UNUSED; 271 void *data ATTRIBUTE_UNUSED; 272 void *htab ATTRIBUTE_UNUSED; 273{ 274 return NULL_TREE; 275} 276 277/* lang_hooks.tree_inlining.cannot_inline_tree_fn is called to 278 determine whether there are language-specific reasons for not 279 inlining a given function. */ 280 281int 282lhd_tree_inlining_cannot_inline_tree_fn (fnp) 283 tree *fnp; 284{ 285 if (flag_really_no_inline 286 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (*fnp)) == NULL) 287 return 1; 288 289 return 0; 290} 291 292/* lang_hooks.tree_inlining.disregard_inline_limits is called to 293 determine whether a function should be considered for inlining even 294 if it would exceed inlining limits. */ 295 296int 297lhd_tree_inlining_disregard_inline_limits (fn) 298 tree fn; 299{ 300 if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) != NULL) 301 return 1; 302 303 return 0; 304} 305 306/* lang_hooks.tree_inlining.add_pending_fn_decls is called before 307 starting to inline a function, to push any language-specific 308 functions that should not be inlined into the current function, 309 into VAFNP. PFN is the top of varray, and should be returned if no 310 functions are pushed into VAFNP. The top of the varray should be 311 returned. */ 312 313tree 314lhd_tree_inlining_add_pending_fn_decls (vafnp, pfn) 315 void *vafnp ATTRIBUTE_UNUSED; 316 tree pfn; 317{ 318 return pfn; 319} 320 321/* lang_hooks.tree_inlining.tree_chain_matters_p indicates whether the 322 TREE_CHAIN of a language-specific tree node is relevant, i.e., 323 whether it should be walked, copied and preserved across copies. */ 324 325int 326lhd_tree_inlining_tree_chain_matters_p (t) 327 tree t ATTRIBUTE_UNUSED; 328{ 329 return 0; 330} 331 332/* lang_hooks.tree_inlining.auto_var_in_fn_p is called to determine 333 whether VT is an automatic variable defined in function FT. */ 334 335int 336lhd_tree_inlining_auto_var_in_fn_p (var, fn) 337 tree var, fn; 338{ 339 return (DECL_P (var) && DECL_CONTEXT (var) == fn 340 && (((TREE_CODE (var) == VAR_DECL || TREE_CODE (var) == PARM_DECL) 341 && ! TREE_STATIC (var)) 342 || TREE_CODE (var) == LABEL_DECL 343 || TREE_CODE (var) == RESULT_DECL)); 344} 345 346/* lang_hooks.tree_inlining.copy_res_decl_for_inlining should return a 347 declaration for the result RES of function FN to be inlined into 348 CALLER. NDP points to an integer that should be set in case a new 349 declaration wasn't created (presumably because RES was of aggregate 350 type, such that a TARGET_EXPR is used for the result). TEXPS is a 351 pointer to a varray with the stack of TARGET_EXPRs seen while 352 inlining functions into caller; the top of TEXPS is supposed to 353 match RES. */ 354 355tree 356lhd_tree_inlining_copy_res_decl_for_inlining (res, fn, caller, 357 dm, ndp, texps) 358 tree res, fn, caller; 359 void *dm ATTRIBUTE_UNUSED; 360 int *ndp ATTRIBUTE_UNUSED; 361 void *texps ATTRIBUTE_UNUSED; 362{ 363 return copy_decl_for_inlining (res, fn, caller); 364} 365 366/* lang_hooks.tree_inlining.anon_aggr_type_p determines whether T is a 367 type node representing an anonymous aggregate (union, struct, etc), 368 i.e., one whose members are in the same scope as the union itself. */ 369 370int 371lhd_tree_inlining_anon_aggr_type_p (t) 372 tree t ATTRIBUTE_UNUSED; 373{ 374 return 0; 375} 376 377/* lang_hooks.tree_inlining.start_inlining and end_inlining perform any 378 language-specific bookkeeping necessary for processing 379 FN. start_inlining returns nonzero if inlining should proceed, zero if 380 not. 381 382 For instance, the C++ version keeps track of template instantiations to 383 avoid infinite recursion. */ 384 385int 386lhd_tree_inlining_start_inlining (fn) 387 tree fn ATTRIBUTE_UNUSED; 388{ 389 return 1; 390} 391 392void 393lhd_tree_inlining_end_inlining (fn) 394 tree fn ATTRIBUTE_UNUSED; 395{ 396} 397 398/* lang_hooks.tree_inlining.convert_parm_for_inlining performs any 399 language-specific conversion before assigning VALUE to PARM. */ 400 401tree 402lhd_tree_inlining_convert_parm_for_inlining (parm, value, fndecl) 403 tree parm ATTRIBUTE_UNUSED; 404 tree value; 405 tree fndecl ATTRIBUTE_UNUSED; 406{ 407 return value; 408} 409 410/* lang_hooks.tree_dump.dump_tree: Dump language-specific parts of tree 411 nodes. Returns nonzero if it does not want the usual dumping of the 412 second argument. */ 413 414int 415lhd_tree_dump_dump_tree (di, t) 416 void *di ATTRIBUTE_UNUSED; 417 tree t ATTRIBUTE_UNUSED; 418{ 419 return 0; 420} 421 422/* lang_hooks.tree_dump.type_qual: Determine type qualifiers in a 423 language-specific way. */ 424 425int 426lhd_tree_dump_type_quals (t) 427 tree t; 428{ 429 return TYPE_QUALS (t); 430} 431 432/* lang_hooks.expr_size: Determine the size of the value of an expression T 433 in a language-specific way. Returns a tree for the size in bytes. */ 434 435tree 436lhd_expr_size (exp) 437 tree exp; 438{ 439 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' 440 && DECL_SIZE_UNIT (exp) != 0) 441 return DECL_SIZE_UNIT (exp); 442 else 443 return size_in_bytes (TREE_TYPE (exp)); 444} 445 446/* Return true if decl, which is a function decl, may be called by a 447 sibcall. */ 448 449bool 450lhd_decl_ok_for_sibcall (decl) 451 tree decl ATTRIBUTE_UNUSED; 452{ 453 return true; 454} 455 456/* lang_hooks.decls.final_write_globals: perform final processing on 457 global variables. */ 458void 459write_global_declarations () 460{ 461 /* Really define vars that have had only a tentative definition. 462 Really output inline functions that must actually be callable 463 and have not been output so far. */ 464 465 tree globals = (*lang_hooks.decls.getdecls) (); 466 int len = list_length (globals); 467 tree *vec = (tree *) xmalloc (sizeof (tree) * len); 468 int i; 469 tree decl; 470 471 /* Process the decls in reverse order--earliest first. 472 Put them into VEC from back to front, then take out from front. */ 473 474 for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl)) 475 vec[len - i - 1] = decl; 476 477 wrapup_global_declarations (vec, len); 478 479 check_global_declarations (vec, len); 480 481 /* Clean up. */ 482 free (vec); 483} 484