gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004, 2005, 2006 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
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 Boston, MA 02110-1301, USA.  */
  20
  21 #ifndef GCC_LANG_HOOKS_H
  22 #define GCC_LANG_HOOKS_H
  23
  24 /* This file should be #include-d after tree.h.  */
  25
  26 struct diagnostic_context;
  27
  28 struct gimplify_omp_ctx;
  29
  30 /* A print hook for print_tree ().  */
  31 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  32
  33 /* The following hooks are documented in langhooks.c.  Must not be
  34    NULL.  */
  35
  36 struct lang_hooks_for_tree_inlining
  37 {
  38   tree (*walk_subtrees) (tree *, int *,
  39                          tree (*) (tree *, int *, void *),
  40                          void *, struct pointer_set_t*);
  41   int (*cannot_inline_tree_fn) (tree *);
  42   int (*disregard_inline_limits) (tree);
  43   int (*auto_var_in_fn_p) (tree, tree);
  44   bool (*var_mod_type_p) (tree, tree);
  45   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  46 };
  47
  48 struct lang_hooks_for_callgraph
  49 {
  50   /* The node passed is a language-specific tree node.  If its contents
  51      are relevant to use of other declarations, mark them.  */
  52   tree (*analyze_expr) (tree *, int *, tree);
  53
  54   /* Produce RTL for function passed as argument.  */
  55   void (*expand_function) (tree);
  56 };
  57
  58 /* Lang hooks for management of language-specific data or status
  59    when entering / leaving functions etc.  */
  60 struct lang_hooks_for_functions
  61 {
  62   /* Called when entering a function.  */
  63   void (*init) (struct function *);
  64
  65   /* Called when leaving a function.  */
  66   void (*final) (struct function *);
  67
  68   /* Called when entering a nested function.  */
  69   void (*enter_nested) (struct function *);
  70
  71   /* Called when leaving a nested function.  */
  72   void (*leave_nested) (struct function *);
  73
  74   /* Determines if it's ok for a function to have no noreturn attribute.  */
  75   bool (*missing_noreturn_ok_p) (tree);
  76 };
  77
  78 /* The following hooks are used by tree-dump.c.  */
  79
  80 struct lang_hooks_for_tree_dump
  81 {
  82   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  83      does not want the usual dumping of the second argument.  */
  84   bool (*dump_tree) (void *, tree);
  85
  86   /* Determine type qualifiers in a language-specific way.  */
  87   int (*type_quals) (tree);
  88 };
  89
  90 /* Hooks related to types.  */
  91
  92 struct lang_hooks_for_types
  93 {
  94   /* Return a new type (with the indicated CODE), doing whatever
  95      language-specific processing is required.  */
  96   tree (*make_type) (enum tree_code);
  97
  98   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
  99      mode.  */
 100   tree (*type_for_mode) (enum machine_mode, int);
 101
 102   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 103      integer type with at least that precision.  */
 104   tree (*type_for_size) (unsigned, int);
 105
 106   /* Given an integer type T, return a type like T but signed.
 107      If T is signed, the value is T.  */
 108   tree (*signed_type) (tree);
 109
 110   /* Return a type the same as TYPE except unsigned or signed
 111      according to UNSIGNEDP.  */
 112   tree (*signed_or_unsigned_type) (int, tree);
 113
 114   /* True if the type is an instantiation of a generic type,
 115      e.g. C++ template implicit specializations.  */
 116   bool (*generic_p) (tree);
 117
 118   /* Given a type, apply default promotions to unnamed function
 119      arguments and return the new type.  Return the same type if no
 120      change.  Required by any language that supports variadic
 121      arguments.  The default hook dies.  */
 122   tree (*type_promotes_to) (tree);
 123
 124   /* Register TYPE as a builtin type with the indicated NAME.  The
 125      TYPE is placed in the outermost lexical scope.  The semantics
 126      should be analogous to:
 127
 128        typedef TYPE NAME;
 129
 130      in C.  The default hook ignores the declaration.  */
 131   void (*register_builtin_type) (tree, const char *);
 132
 133   /* This routine is called in tree.c to print an error message for
 134      invalid use of an incomplete type.  VALUE is the expression that
 135      was used (or 0 if that isn't known) and TYPE is the type that was
 136      invalid.  */
 137   void (*incomplete_type_error) (tree value, tree type);
 138
 139   /* Called from assign_temp to return the maximum size, if there is one,
 140      for a type.  */
 141   tree (*max_size) (tree);
 142
 143   /* Register language specific type size variables as potentially OpenMP
 144      firstprivate variables.  */
 145   void (*omp_firstprivatize_type_sizes) (struct gimplify_omp_ctx *, tree);
 146
 147   /* Nonzero if types that are identical are to be hashed so that only
 148      one copy is kept.  If a language requires unique types for each
 149      user-specified type, such as Ada, this should be set to TRUE.  */
 150   bool hash_types;
 151 };
 152
 153 /* Language hooks related to decls and the symbol table.  */
 154
 155 struct lang_hooks_for_decls
 156 {
 157   /* Returns nonzero if we are in the global binding level.  Ada
 158      returns -1 for an undocumented reason used in stor-layout.c.  */
 159   int (*global_bindings_p) (void);
 160
 161   /* Insert BLOCK at the end of the list of subblocks of the
 162      current binding level.  This is used when a BIND_EXPR is expanded,
 163      to handle the BLOCK node inside the BIND_EXPR.  */
 164   void (*insert_block) (tree);
 165
 166   /* Function to add a decl to the current scope level.  Takes one
 167      argument, a decl to add.  Returns that decl, or, if the same
 168      symbol is already declared, may return a different decl for that
 169      name.  */
 170   tree (*pushdecl) (tree);
 171
 172   /* Returns the chain of decls so far in the current scope level.  */
 173   tree (*getdecls) (void);
 174
 175   /* Returns true when we should warn for an unused global DECL.
 176      We will already have checked that it has static binding.  */
 177   bool (*warn_unused_global) (tree);
 178
 179   /* Obtain a list of globals and do final output on them at end
 180      of compilation */
 181   void (*final_write_globals) (void);
 182
 183   /* True if this decl may be called via a sibcall.  */
 184   bool (*ok_for_sibcall) (tree);
 185
 186   /* Return the COMDAT group into which this DECL should be placed.
 187      It is known that the DECL belongs in *some* COMDAT group when
 188      this hook is called.  The return value will be used immediately,
 189      but not explicitly deallocated, so implementations should not use
 190      xmalloc to allocate the string returned.  (Typically, the return
 191      value will be the string already stored in an
 192      IDENTIFIER_NODE.)  */
 193   const char * (*comdat_group) (tree);
 194
 195   /* True if OpenMP should privatize what this DECL points to rather
 196      than the DECL itself.  */
 197   bool (*omp_privatize_by_reference) (tree);
 198
 199   /* Return sharing kind if OpenMP sharing attribute of DECL is
 200      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 201   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 202
 203   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 204      disregarded in OpenMP construct, because it is going to be
 205      remapped during OpenMP lowering.  SHARED is true if DECL
 206      is going to be shared, false if it is going to be privatized.  */
 207   bool (*omp_disregard_value_expr) (tree, bool);
 208
 209   /* Return true if DECL that is shared iff SHARED is true should
 210      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 211   bool (*omp_private_debug_clause) (tree, bool);
 212
 213   /* Build and return code for a default constructor for DECL in
 214      response to CLAUSE.  Return NULL if nothing to be done.  */
 215   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 216
 217   /* Build and return code for a copy constructor from SRC to DST.  */
 218   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 219
 220   /* Similarly, except use an assignment operator instead.  */
 221   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 222
 223   /* Build and return code destructing DECL.  Return NULL if nothing
 224      to be done.  */
 225   tree (*omp_clause_dtor) (tree clause, tree decl);
 226 };
 227
 228 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 229
 230 struct lang_hooks
 231 {
 232   /* String identifying the front end.  e.g. "GNU C++".  */
 233   const char *name;
 234
 235   /* sizeof (struct lang_identifier), so make_node () creates
 236      identifier nodes long enough for the language-specific slots.  */
 237   size_t identifier_size;
 238
 239   /* Determines the size of any language-specific tcc_constant or
 240      tcc_exceptional nodes.  Since it is called from make_node, the
 241      only information available is the tree code.  Expected to die
 242      on unrecognized codes.  */
 243   size_t (*tree_size) (enum tree_code);
 244
 245   /* The first callback made to the front end, for simple
 246      initialization needed before any calls to handle_option.  Return
 247      the language mask to filter the switch array with.  */
 248   unsigned int (*init_options) (unsigned int argc, const char **argv);
 249
 250   /* Callback used to perform language-specific initialization for the
 251      global diagnostic context structure.  */
 252   void (*initialize_diagnostics) (struct diagnostic_context *);
 253
 254   /* Handle the switch CODE, which has real type enum opt_code from
 255      options.h.  If the switch takes an argument, it is passed in ARG
 256      which points to permanent storage.  The handler is responsible for
 257      checking whether ARG is NULL, which indicates that no argument
 258      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 259      for the positive and negative forms respectively.
 260
 261      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 262      valid and should not be treated as language-independent too.  */
 263   int (*handle_option) (size_t code, const char *arg, int value);
 264
 265   /* Return false to use the default complaint about a missing
 266      argument, otherwise output a complaint and return true.  */
 267   bool (*missing_argument) (const char *opt, size_t code);
 268
 269   /* Called when all command line options have been parsed to allow
 270      further processing and initialization
 271
 272      Should return true to indicate that a compiler back-end is
 273      not required, such as with the -E option.
 274
 275      If errorcount is nonzero after this call the compiler exits
 276      immediately and the finish hook is not called.  */
 277   bool (*post_options) (const char **);
 278
 279   /* Called after post_options to initialize the front end.  Return
 280      false to indicate that no further compilation be performed, in
 281      which case the finish hook is called immediately.  */
 282   bool (*init) (void);
 283
 284   /* Called at the end of compilation, as a finalizer.  */
 285   void (*finish) (void);
 286
 287   /* Parses the entire file.  The argument is nonzero to cause bison
 288      parsers to dump debugging information during parsing.  */
 289   void (*parse_file) (int);
 290
 291   /* Called immediately after parsing to clear the binding stack.  */
 292   void (*clear_binding_stack) (void);
 293
 294   /* Called to obtain the alias set to be used for an expression or type.
 295      Returns -1 if the language does nothing special for it.  */
 296   HOST_WIDE_INT (*get_alias_set) (tree);
 297
 298   /* Called with an expression that is to be processed as a constant.
 299      Returns either the same expression or a language-independent
 300      constant equivalent to its input.  */
 301   tree (*expand_constant) (tree);
 302
 303   /* Called by expand_expr for language-specific tree codes.
 304      Fourth argument is actually an enum expand_modifier.  */
 305   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 306
 307   /* Called by expand_expr to generate the definition of a decl.  Returns
 308      1 if handled, 0 otherwise.  */
 309   int (*expand_decl) (tree);
 310
 311   /* Function to finish handling an incomplete decl at the end of
 312      compilation.  Default hook is does nothing.  */
 313   void (*finish_incomplete_decl) (tree);
 314
 315   /* Mark EXP saying that we need to be able to take the address of
 316      it; it should not be allocated in a register.  Return true if
 317      successful.  */
 318   bool (*mark_addressable) (tree);
 319
 320   /* Hook called by staticp for language-specific tree codes.  */
 321   tree (*staticp) (tree);
 322
 323   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 324      DECL_NODE with a newly GC-allocated copy.  */
 325   void (*dup_lang_specific_decl) (tree);
 326
 327   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 328      thing that the assembler should talk about, set
 329      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 330      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 331      assembler does not talk about it.  */
 332   void (*set_decl_assembler_name) (tree);
 333
 334   /* Nonzero if operations on types narrower than their mode should
 335      have their results reduced to the precision of the type.  */
 336   bool reduce_bit_field_operations;
 337
 338   /* Nonzero if this front end does not generate a dummy BLOCK between
 339      the outermost scope of the function and the FUNCTION_DECL.  See
 340      is_body_block in stmt.c, and its callers.  */
 341   bool no_body_blocks;
 342
 343   /* The front end can add its own statistics to -fmem-report with
 344      this hook.  It should output to stderr.  */
 345   void (*print_statistics) (void);
 346
 347   /* Called by print_tree when there is a tree of class tcc_exceptional
 348      that it doesn't know how to display.  */
 349   lang_print_tree_hook print_xnode;
 350
 351   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 352      and IDENTIFIER_NODE nodes.  */
 353   lang_print_tree_hook print_decl;
 354   lang_print_tree_hook print_type;
 355   lang_print_tree_hook print_identifier;
 356
 357   /* Computes the name to use to print a declaration.  DECL is the
 358      non-NULL declaration in question.  VERBOSITY determines what
 359      information will be printed: 0: DECL_NAME, demangled as
 360      necessary.  1: and scope information.  2: and any other
 361      information that might be interesting, such as function parameter
 362      types in C++.  */
 363   const char *(*decl_printable_name) (tree decl, int verbosity);
 364
 365   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 366      information will be printed: 0: DECL_NAME, demangled as
 367      necessary.  1: and scope information.  */
 368   const char *(*dwarf_name) (tree, int verbosity);
 369
 370   /* This compares two types for equivalence ("compatible" in C-based languages).
 371      This routine should only return 1 if it is sure.  It should not be used
 372      in contexts where erroneously returning 0 causes problems.  */
 373   int (*types_compatible_p) (tree x, tree y);
 374
 375   /* Given a CALL_EXPR, return a function decl that is its target.  */
 376   tree (*lang_get_callee_fndecl) (tree);
 377
 378   /* Called by report_error_function to print out function name.  */
 379   void (*print_error_function) (struct diagnostic_context *, const char *);
 380
 381   /* Called from expr_size to calculate the size of the value of an
 382      expression in a language-dependent way.  Returns a tree for the size
 383      in bytes.  A frontend can call lhd_expr_size to get the default
 384      semantics in cases that it doesn't want to handle specially.  */
 385   tree (*expr_size) (tree);
 386
 387   /* Convert a character from the host's to the target's character
 388      set.  The character should be in what C calls the "basic source
 389      character set" (roughly, the set of characters defined by plain
 390      old ASCII).  The default is to return the character unchanged,
 391      which is correct in most circumstances.  Note that both argument
 392      and result should be sign-extended under -fsigned-char,
 393      zero-extended under -fno-signed-char.  */
 394   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 395
 396   /* Pointers to machine-independent attribute tables, for front ends
 397      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 398      table of attributes specific to the language, a table of
 399      attributes common to two or more languages (to allow easy
 400      sharing), and a table of attributes for checking formats.  */
 401   const struct attribute_spec *attribute_table;
 402   const struct attribute_spec *common_attribute_table;
 403   const struct attribute_spec *format_attribute_table;
 404
 405   /* Function-related language hooks.  */
 406   struct lang_hooks_for_functions function;
 407
 408   struct lang_hooks_for_tree_inlining tree_inlining;
 409
 410   struct lang_hooks_for_callgraph callgraph;
 411
 412   struct lang_hooks_for_tree_dump tree_dump;
 413
 414   struct lang_hooks_for_decls decls;
 415
 416   struct lang_hooks_for_types types;
 417
 418   /* Perform language-specific gimplification on the argument.  Returns an
 419      enum gimplify_status, though we can't see that type here.  */
 420   int (*gimplify_expr) (tree *, tree *, tree *);
 421
 422   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 423      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 424   tree (*fold_obj_type_ref) (tree, tree);
 425
 426   /* Do language specific processing in the builtin function DECL  */
 427   tree (*builtin_function) (tree decl);
 428
 429   /* Used to set up the tree_contains_structure array for a frontend. */
 430   void (*init_ts) (void);
 431
 432   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 433      to a contained expression or DECL, possibly updating *TC, *TI or
 434      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 435      TREE_SIDE_EFFECTS need updating.  */
 436   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 437
 438   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 439      and langhooks.c accordingly.  */
 440 };
 441
 442 /* Each front end provides its own.  */
 443 extern const struct lang_hooks lang_hooks;
 444 extern tree add_builtin_function (const char *name, tree type,
 445                                   int function_code, enum built_in_class cl,
 446                                   const char *library_name,
 447                                   tree attrs);
 448 extern tree lhd_signed_or_unsigned_type (int unsignedp, tree type);
 449
 450 #endif /* GCC_LANG_HOOKS_H */