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 unsigned.
 107      If T is unsigned, the value is T.  */
 108   tree (*unsigned_type) (tree);
 109
 110   /* Given an integer type T, return a type like T but signed.
 111      If T is signed, the value is T.  */
 112   tree (*signed_type) (tree);
 113
 114   /* Return a type the same as TYPE except unsigned or signed
 115      according to UNSIGNEDP.  */
 116   tree (*signed_or_unsigned_type) (int, 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   /* Do necessary preparations before assemble_variable can proceed.  */
 184   void (*prepare_assemble_variable) (tree);
 185
 186   /* True if this decl may be called via a sibcall.  */
 187   bool (*ok_for_sibcall) (tree);
 188
 189   /* Return the COMDAT group into which this DECL should be placed.
 190      It is known that the DECL belongs in *some* COMDAT group when
 191      this hook is called.  The return value will be used immediately,
 192      but not explicitly deallocated, so implementations should not use
 193      xmalloc to allocate the string returned.  (Typically, the return
 194      value will be the string already stored in an
 195      IDENTIFIER_NODE.)  */
 196   const char * (*comdat_group) (tree);
 197
 198   /* True if OpenMP should privatize what this DECL points to rather
 199      than the DECL itself.  */
 200   bool (*omp_privatize_by_reference) (tree);
 201
 202   /* Return sharing kind if OpenMP sharing attribute of DECL is
 203      predetermined, OMP_CLAUSE_DEFAULT_UNSPECIFIED otherwise.  */
 204   enum omp_clause_default_kind (*omp_predetermined_sharing) (tree);
 205
 206   /* Return true if DECL's DECL_VALUE_EXPR (if any) should be
 207      disregarded in OpenMP construct, because it is going to be
 208      remapped during OpenMP lowering.  SHARED is true if DECL
 209      is going to be shared, false if it is going to be privatized.  */
 210   bool (*omp_disregard_value_expr) (tree, bool);
 211
 212   /* Return true if DECL that is shared iff SHARED is true should
 213      be put into OMP_CLAUSE_PRIVATE_DEBUG.  */
 214   bool (*omp_private_debug_clause) (tree, bool);
 215
 216   /* Build and return code for a default constructor for DECL in
 217      response to CLAUSE.  Return NULL if nothing to be done.  */
 218   tree (*omp_clause_default_ctor) (tree clause, tree decl);
 219
 220   /* Build and return code for a copy constructor from SRC to DST.  */
 221   tree (*omp_clause_copy_ctor) (tree clause, tree dst, tree src);
 222
 223   /* Similarly, except use an assignment operator instead.  */
 224   tree (*omp_clause_assign_op) (tree clause, tree dst, tree src);
 225
 226   /* Build and return code destructing DECL.  Return NULL if nothing
 227      to be done.  */
 228   tree (*omp_clause_dtor) (tree clause, tree decl);
 229 };
 230
 231 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 232
 233 struct lang_hooks
 234 {
 235   /* String identifying the front end.  e.g. "GNU C++".  */
 236   const char *name;
 237
 238   /* sizeof (struct lang_identifier), so make_node () creates
 239      identifier nodes long enough for the language-specific slots.  */
 240   size_t identifier_size;
 241
 242   /* Determines the size of any language-specific tcc_constant or
 243      tcc_exceptional nodes.  Since it is called from make_node, the
 244      only information available is the tree code.  Expected to die
 245      on unrecognized codes.  */
 246   size_t (*tree_size) (enum tree_code);
 247
 248   /* The first callback made to the front end, for simple
 249      initialization needed before any calls to handle_option.  Return
 250      the language mask to filter the switch array with.  */
 251   unsigned int (*init_options) (unsigned int argc, const char **argv);
 252
 253   /* Callback used to perform language-specific initialization for the
 254      global diagnostic context structure.  */
 255   void (*initialize_diagnostics) (struct diagnostic_context *);
 256
 257   /* Handle the switch CODE, which has real type enum opt_code from
 258      options.h.  If the switch takes an argument, it is passed in ARG
 259      which points to permanent storage.  The handler is responsible for
 260      checking whether ARG is NULL, which indicates that no argument
 261      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 262      for the positive and negative forms respectively.
 263
 264      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 265      valid and should not be treated as language-independent too.  */
 266   int (*handle_option) (size_t code, const char *arg, int value);
 267
 268   /* Return false to use the default complaint about a missing
 269      argument, otherwise output a complaint and return true.  */
 270   bool (*missing_argument) (const char *opt, size_t code);
 271
 272   /* Called when all command line options have been parsed to allow
 273      further processing and initialization
 274
 275      Should return true to indicate that a compiler back-end is
 276      not required, such as with the -E option.
 277
 278      If errorcount is nonzero after this call the compiler exits
 279      immediately and the finish hook is not called.  */
 280   bool (*post_options) (const char **);
 281
 282   /* Called after post_options to initialize the front end.  Return
 283      false to indicate that no further compilation be performed, in
 284      which case the finish hook is called immediately.  */
 285   bool (*init) (void);
 286
 287   /* Called at the end of compilation, as a finalizer.  */
 288   void (*finish) (void);
 289
 290   /* Parses the entire file.  The argument is nonzero to cause bison
 291      parsers to dump debugging information during parsing.  */
 292   void (*parse_file) (int);
 293
 294   /* Called immediately after parsing to clear the binding stack.  */
 295   void (*clear_binding_stack) (void);
 296
 297   /* Called to obtain the alias set to be used for an expression or type.
 298      Returns -1 if the language does nothing special for it.  */
 299   HOST_WIDE_INT (*get_alias_set) (tree);
 300
 301   /* Called with an expression that is to be processed as a constant.
 302      Returns either the same expression or a language-independent
 303      constant equivalent to its input.  */
 304   tree (*expand_constant) (tree);
 305
 306   /* Called by expand_expr for language-specific tree codes.
 307      Fourth argument is actually an enum expand_modifier.  */
 308   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 309
 310   /* Called by expand_expr to generate the definition of a decl.  Returns
 311      1 if handled, 0 otherwise.  */
 312   int (*expand_decl) (tree);
 313
 314   /* Function to finish handling an incomplete decl at the end of
 315      compilation.  Default hook is does nothing.  */
 316   void (*finish_incomplete_decl) (tree);
 317
 318   /* Mark EXP saying that we need to be able to take the address of
 319      it; it should not be allocated in a register.  Return true if
 320      successful.  */
 321   bool (*mark_addressable) (tree);
 322
 323   /* Hook called by staticp for language-specific tree codes.  */
 324   tree (*staticp) (tree);
 325
 326   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 327      DECL_NODE with a newly GC-allocated copy.  */
 328   void (*dup_lang_specific_decl) (tree);
 329
 330   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 331      thing that the assembler should talk about, set
 332      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 333      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 334      assembler does not talk about it.  */
 335   void (*set_decl_assembler_name) (tree);
 336
 337   /* Nonzero if operations on types narrower than their mode should
 338      have their results reduced to the precision of the type.  */
 339   bool reduce_bit_field_operations;
 340
 341   /* Nonzero if this front end does not generate a dummy BLOCK between
 342      the outermost scope of the function and the FUNCTION_DECL.  See
 343      is_body_block in stmt.c, and its callers.  */
 344   bool no_body_blocks;
 345
 346   /* The front end can add its own statistics to -fmem-report with
 347      this hook.  It should output to stderr.  */
 348   void (*print_statistics) (void);
 349
 350   /* Called by print_tree when there is a tree of class tcc_exceptional
 351      that it doesn't know how to display.  */
 352   lang_print_tree_hook print_xnode;
 353
 354   /* Called to print language-dependent parts of tcc_decl, tcc_type,
 355      and IDENTIFIER_NODE nodes.  */
 356   lang_print_tree_hook print_decl;
 357   lang_print_tree_hook print_type;
 358   lang_print_tree_hook print_identifier;
 359
 360   /* Computes the name to use to print a declaration.  DECL is the
 361      non-NULL declaration in question.  VERBOSITY determines what
 362      information will be printed: 0: DECL_NAME, demangled as
 363      necessary.  1: and scope information.  2: and any other
 364      information that might be interesting, such as function parameter
 365      types in C++.  */
 366   const char *(*decl_printable_name) (tree decl, int verbosity);
 367
 368   /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
 369      information will be printed: 0: DECL_NAME, demangled as
 370      necessary.  1: and scope information.  */
 371   const char *(*dwarf_name) (tree, int verbosity);
 372
 373   /* This compares two types for equivalence ("compatible" in C-based languages).
 374      This routine should only return 1 if it is sure.  It should not be used
 375      in contexts where erroneously returning 0 causes problems.  */
 376   int (*types_compatible_p) (tree x, tree y);
 377
 378   /* Given a CALL_EXPR, return a function decl that is its target.  */
 379   tree (*lang_get_callee_fndecl) (tree);
 380
 381   /* Called by report_error_function to print out function name.  */
 382   void (*print_error_function) (struct diagnostic_context *, const char *);
 383
 384   /* Called from expr_size to calculate the size of the value of an
 385      expression in a language-dependent way.  Returns a tree for the size
 386      in bytes.  A frontend can call lhd_expr_size to get the default
 387      semantics in cases that it doesn't want to handle specially.  */
 388   tree (*expr_size) (tree);
 389
 390   /* Convert a character from the host's to the target's character
 391      set.  The character should be in what C calls the "basic source
 392      character set" (roughly, the set of characters defined by plain
 393      old ASCII).  The default is to return the character unchanged,
 394      which is correct in most circumstances.  Note that both argument
 395      and result should be sign-extended under -fsigned-char,
 396      zero-extended under -fno-signed-char.  */
 397   HOST_WIDE_INT (*to_target_charset) (HOST_WIDE_INT);
 398
 399   /* Pointers to machine-independent attribute tables, for front ends
 400      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 401      table of attributes specific to the language, a table of
 402      attributes common to two or more languages (to allow easy
 403      sharing), and a table of attributes for checking formats.  */
 404   const struct attribute_spec *attribute_table;
 405   const struct attribute_spec *common_attribute_table;
 406   const struct attribute_spec *format_attribute_table;
 407
 408   /* Function-related language hooks.  */
 409   struct lang_hooks_for_functions function;
 410
 411   struct lang_hooks_for_tree_inlining tree_inlining;
 412
 413   struct lang_hooks_for_callgraph callgraph;
 414
 415   struct lang_hooks_for_tree_dump tree_dump;
 416
 417   struct lang_hooks_for_decls decls;
 418
 419   struct lang_hooks_for_types types;
 420
 421   /* Perform language-specific gimplification on the argument.  Returns an
 422      enum gimplify_status, though we can't see that type here.  */
 423   int (*gimplify_expr) (tree *, tree *, tree *);
 424
 425   /* Fold an OBJ_TYPE_REF expression to the address of a function.
 426      KNOWN_TYPE carries the true type of the OBJ_TYPE_REF_OBJECT.  */
 427   tree (*fold_obj_type_ref) (tree, tree);
 428
 429   /* Do language specific processing in the builtin function DECL  */
 430   tree (*builtin_function) (tree decl);
 431
 432   /* Used to set up the tree_contains_structure array for a frontend. */
 433   void (*init_ts) (void);
 434
 435   /* Called by recompute_tree_invariant_for_addr_expr to go from EXPR
 436      to a contained expression or DECL, possibly updating *TC, *TI or
 437      *SE if in the process TREE_CONSTANT, TREE_INVARIANT or
 438      TREE_SIDE_EFFECTS need updating.  */
 439   tree (*expr_to_decl) (tree expr, bool *tc, bool *ti, bool *se);
 440
 441   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 442      and langhooks.c accordingly.  */
 443 };
 444
 445 /* Each front end provides its own.  */
 446 extern const struct lang_hooks lang_hooks;
 447 extern tree add_builtin_function (const char *name, tree type,
 448                                   int function_code, enum built_in_class cl,
 449                                   const char *library_name,
 450                                   tree attrs);
 451 extern tree lhd_signed_or_unsigned_type (int unsignedp, tree type);
 452
 453 #endif /* GCC_LANG_HOOKS_H */