gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003, 2004 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, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, 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 /* A print hook for print_tree ().  */
  29 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  30
  31 /* The following hooks are documented in langhooks.c.  Must not be
  32    NULL.  */
  33
  34 struct lang_hooks_for_tree_inlining
  35 {
  36   tree (*walk_subtrees) (tree *, int *,
  37                          tree (*) (tree *, int *, void *),
  38                          void *, void *);
  39   int (*cannot_inline_tree_fn) (tree *);
  40   int (*disregard_inline_limits) (tree);
  41   tree (*add_pending_fn_decls) (void *, tree);
  42   int (*tree_chain_matters_p) (tree);
  43   int (*auto_var_in_fn_p) (tree, tree);
  44   tree (*copy_res_decl_for_inlining) (tree, tree, tree,
  45                                       void *, int *, tree);
  46   int (*anon_aggr_type_p) (tree);
  47   bool (*var_mod_type_p) (tree);
  48   int (*start_inlining) (tree);
  49   void (*end_inlining) (tree);
  50   tree (*convert_parm_for_inlining) (tree, tree, tree, int);
  51   int (*estimate_num_insns) (tree);
  52 };
  53
  54 struct lang_hooks_for_callgraph
  55 {
  56   /* The node passed is a language-specific tree node.  If its contents
  57      are relevant to use of other declarations, mark them.  */
  58   tree (*analyze_expr) (tree *, int *, tree);
  59
  60   /* Produce RTL for function passed as argument.  */
  61   void (*expand_function) (tree);
  62 };
  63
  64 /* Lang hooks for management of language-specific data or status
  65    when entering / leaving functions etc.  */
  66 struct lang_hooks_for_functions
  67 {
  68   /* Called when entering a function.  */
  69   void (*init) (struct function *);
  70
  71   /* Called when leaving a function.  */
  72   void (*final) (struct function *);
  73
  74   /* Called when entering a nested function.  */
  75   void (*enter_nested) (struct function *);
  76
  77   /* Called when leaving a nested function.  */
  78   void (*leave_nested) (struct function *);
  79
  80   /* Determines if it's ok for a function to have no noreturn attribute.  */
  81   bool (*missing_noreturn_ok_p) (tree);
  82 };
  83
  84 /* The following hooks are used by tree-dump.c.  */
  85
  86 struct lang_hooks_for_tree_dump
  87 {
  88   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  89      does not want the usual dumping of the second argument.  */
  90   bool (*dump_tree) (void *, tree);
  91
  92   /* Determine type qualifiers in a language-specific way.  */
  93   int (*type_quals) (tree);
  94 };
  95
  96 /* Hooks related to types.  */
  97
  98 struct lang_hooks_for_types
  99 {
 100   /* Return a new type (with the indicated CODE), doing whatever
 101      language-specific processing is required.  */
 102   tree (*make_type) (enum tree_code);
 103
 104   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 105      mode.  */
 106   tree (*type_for_mode) (enum machine_mode, int);
 107
 108   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 109      integer type with at least that precision.  */
 110   tree (*type_for_size) (unsigned, int);
 111
 112   /* Given an integer type T, return a type like T but unsigned.
 113      If T is unsigned, the value is T.  */
 114   tree (*unsigned_type) (tree);
 115
 116   /* Given an integer type T, return a type like T but signed.
 117      If T is signed, the value is T.  */
 118   tree (*signed_type) (tree);
 119
 120   /* Return a type the same as TYPE except unsigned or signed
 121      according to UNSIGNEDP.  */
 122   tree (*signed_or_unsigned_type) (int, tree);
 123
 124   /* Given a type, apply default promotions to unnamed function
 125      arguments and return the new type.  Return the same type if no
 126      change.  Required by any language that supports variadic
 127      arguments.  The default hook aborts.  */
 128   tree (*type_promotes_to) (tree);
 129
 130   /* Register TYPE as a builtin type with the indicated NAME.  The
 131      TYPE is placed in the outermost lexical scope.  The semantics
 132      should be analogous to:
 133
 134        typedef TYPE NAME;
 135
 136      in C.  The default hook ignores the declaration.  */
 137   void (*register_builtin_type) (tree, const char *);
 138
 139   /* This routine is called in tree.c to print an error message for
 140      invalid use of an incomplete type.  VALUE is the expression that
 141      was used (or 0 if that isn't known) and TYPE is the type that was
 142      invalid.  */
 143   void (*incomplete_type_error) (tree value, tree type);
 144
 145   /* Nonzero if types that are identical are to be hashed so that only
 146      one copy is kept.  If a language requires unique types for each
 147      user-specified type, such as Ada, this should be set to TRUE.  */
 148   bool hash_types;
 149 };
 150
 151 /* Language hooks related to decls and the symbol table.  */
 152
 153 struct lang_hooks_for_decls
 154 {
 155   /* Enter a new lexical scope.  Argument is always zero when called
 156      from outside the front end.  */
 157   void (*pushlevel) (int);
 158
 159   /* Exit a lexical scope and return a BINDING for that scope.
 160      Takes three arguments:
 161      KEEP -- nonzero if there were declarations in this scope.
 162      REVERSE -- reverse the order of decls before returning them.
 163      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 164   tree (*poplevel) (int, int, int);
 165
 166   /* Returns nonzero if we are in the global binding level.  Ada
 167      returns -1 for an undocumented reason used in stor-layout.c.  */
 168   int (*global_bindings_p) (void);
 169
 170   /* Insert BLOCK at the end of the list of subblocks of the
 171      current binding level.  This is used when a BIND_EXPR is expanded,
 172      to handle the BLOCK node inside the BIND_EXPR.  */
 173   void (*insert_block) (tree);
 174
 175   /* Set the BLOCK node for the current scope level.  */
 176   void (*set_block) (tree);
 177
 178   /* Function to add a decl to the current scope level.  Takes one
 179      argument, a decl to add.  Returns that decl, or, if the same
 180      symbol is already declared, may return a different decl for that
 181      name.  */
 182   tree (*pushdecl) (tree);
 183
 184   /* Returns the chain of decls so far in the current scope level.  */
 185   tree (*getdecls) (void);
 186
 187   /* Returns true when we should warn for an unused global DECL.
 188      We will already have checked that it has static binding.  */
 189   bool (*warn_unused_global) (tree);
 190
 191   /* Obtain a list of globals and do final output on them at end
 192      of compilation */
 193   void (*final_write_globals) (void);
 194
 195   /* Do necessary preparations before assemble_variable can proceed.  */
 196   void (*prepare_assemble_variable) (tree);
 197
 198   /* True if this decl may be called via a sibcall.  */
 199   bool (*ok_for_sibcall) (tree);
 200 };
 201
 202 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 203
 204 struct lang_hooks
 205 {
 206   /* String identifying the front end.  e.g. "GNU C++".  */
 207   const char *name;
 208
 209   /* sizeof (struct lang_identifier), so make_node () creates
 210      identifier nodes long enough for the language-specific slots.  */
 211   size_t identifier_size;
 212
 213   /* Determines the size of any language-specific 'x' or 'c' nodes.
 214      Since it is called from make_node, the only information available
 215      is the tree code.  Expected to abort on unrecognized codes.  */
 216   size_t (*tree_size) (enum tree_code);
 217
 218   /* The first callback made to the front end, for simple
 219      initialization needed before any calls to handle_option.  Return
 220      the language mask to filter the switch array with.  */
 221   unsigned int (*init_options) (unsigned int argc, const char **argv);
 222
 223   /* Callback used to perform language-specific initialization for the
 224      global diagnostic context structure.  */
 225   void (*initialize_diagnostics) (struct diagnostic_context *);
 226
 227   /* Handle the switch CODE, which has real type enum opt_code from
 228      options.h.  If the switch takes an argument, it is passed in ARG
 229      which points to permanent storage.  The handler is responsible for
 230      checking whether ARG is NULL, which indicates that no argument
 231      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 232      for the positive and negative forms respectively.
 233
 234      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 235      valid and should not be treated as language-independent too.  */
 236   int (*handle_option) (size_t code, const char *arg, int value);
 237
 238   /* Return false to use the default complaint about a missing
 239      argument, otherwise output a complaint and return true.  */
 240   bool (*missing_argument) (const char *opt, size_t code);
 241
 242   /* Called when all command line options have been parsed to allow
 243      further processing and initialization
 244
 245      Should return true to indicate that a compiler back-end is
 246      not required, such as with the -E option.
 247
 248      If errorcount is nonzero after this call the compiler exits
 249      immediately and the finish hook is not called.  */
 250   bool (*post_options) (const char **);
 251
 252   /* Called after post_options to initialize the front end.  Return
 253      false to indicate that no further compilation be performed, in
 254      which case the finish hook is called immediately.  */
 255   bool (*init) (void);
 256
 257   /* Called at the end of compilation, as a finalizer.  */
 258   void (*finish) (void);
 259
 260   /* Parses the entire file.  The argument is nonzero to cause bison
 261      parsers to dump debugging information during parsing.  */
 262   void (*parse_file) (int);
 263
 264   /* Called immediately after parsing to clear the binding stack.  */
 265   void (*clear_binding_stack) (void);
 266
 267   /* Called to obtain the alias set to be used for an expression or type.
 268      Returns -1 if the language does nothing special for it.  */
 269   HOST_WIDE_INT (*get_alias_set) (tree);
 270
 271   /* Called with an expression that is to be processed as a constant.
 272      Returns either the same expression or a language-independent
 273      constant equivalent to its input.  */
 274   tree (*expand_constant) (tree);
 275
 276   /* Called by expand_expr for language-specific tree codes.
 277      Fourth argument is actually an enum expand_modifier.  */
 278   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 279
 280   /* Called by expand_expr to generate the definition of a decl.  Returns
 281      1 if handled, 0 otherwise.  */
 282   int (*expand_decl) (tree);
 283
 284   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 285      operation.
 286
 287      This preparation consists of taking the ordinary representation
 288      of an expression expr and producing a valid tree boolean
 289      expression describing whether expr is nonzero.  We could simply
 290      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 291      but we optimize comparisons, &&, ||, and !.
 292
 293      The result should be an expression of boolean type (if not an
 294      error_mark_node).  */
 295   tree (*truthvalue_conversion) (tree);
 296
 297   /* Hook called by safe_from_p for language-specific tree codes.  It is
 298      up to the language front-end to install a hook if it has any such
 299      codes that safe_from_p needs to know about.  Since same_from_p will
 300      recursively explore the TREE_OPERANDs of an expression, this hook
 301      should not reexamine those pieces.  This routine may recursively
 302      call safe_from_p; it should always pass `0' as the TOP_P
 303      parameter.  */
 304   int (*safe_from_p) (rtx, tree);
 305
 306   /* Function to finish handling an incomplete decl at the end of
 307      compilation.  Default hook is does nothing.  */
 308   void (*finish_incomplete_decl) (tree);
 309
 310   /* Function used by unsafe_for_reeval.  A non-negative number is
 311      returned directly from unsafe_for_reeval, a negative number falls
 312      through.  The default hook returns a negative number.  */
 313   int (*unsafe_for_reeval) (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   int (*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   /* Called before its argument, an UNSAVE_EXPR, is to be
 328      unsaved.  Modify it in-place so that all the evaluate only once
 329      things are cleared out.  */
 330   tree (*unsave_expr_now) (tree);
 331
 332   /* Called by expand_expr to build and return the cleanup-expression
 333      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 334   tree (*maybe_build_cleanup) (tree);
 335
 336   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 337      thing that the assembler should talk about, set
 338      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 339      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 340      assembler does not talk about it.  */
 341   void (*set_decl_assembler_name) (tree);
 342
 343   /* Return nonzero if fold-const is free to use bit-field
 344      optimizations, for instance in fold_truthop().  */
 345   bool (*can_use_bit_fields_p) (void);
 346
 347   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 348   bool honor_readonly;
 349
 350   /* Nonzero if this front end does not generate a dummy BLOCK between
 351      the outermost scope of the function and the FUNCTION_DECL.  See
 352      is_body_block in stmt.c, and its callers.  */
 353   bool no_body_blocks;
 354
 355   /* The front end can add its own statistics to -fmem-report with
 356      this hook.  It should output to stderr.  */
 357   void (*print_statistics) (void);
 358
 359   /* Called by print_tree when there is a tree of class 'x' that it
 360      doesn't know how to display.  */
 361   lang_print_tree_hook print_xnode;
 362
 363   /* Called to print language-dependent parts of a class 'd', class
 364      't', and IDENTIFIER_NODE nodes.  */
 365   lang_print_tree_hook print_decl;
 366   lang_print_tree_hook print_type;
 367   lang_print_tree_hook print_identifier;
 368
 369   /* Computes the name to use to print a declaration.  DECL is the
 370      non-NULL declaration in question.  VERBOSITY determines what
 371      information will be printed: 0: DECL_NAME, demangled as
 372      necessary.  1: and scope information.  2: and any other
 373      information that might be interesting, such as function parameter
 374      types in C++.  */
 375   const char *(*decl_printable_name) (tree decl, int verbosity);
 376
 377   /* This compares two types for equivalence ("compatible" in C-based languages).
 378      This routine should only return 1 if it is sure.  It should not be used
 379      in contexts where erroneously returning 0 causes problems.  */
 380   int (*types_compatible_p) (tree x, tree y);
 381
 382   /* Given a CALL_EXPR, return a function decl that is its target.  */
 383   tree (*lang_get_callee_fndecl) (tree);
 384
 385   /* Called by report_error_function to print out function name.  */
 386   void (*print_error_function) (struct diagnostic_context *, const char *);
 387
 388   /* Called from expr_size to calculate the size of the value of an
 389      expression in a language-dependent way.  Returns a tree for the size
 390      in bytes.  A frontend can call lhd_expr_size to get the default
 391      semantics in cases that it doesn't want to handle specially.  */
 392   tree (*expr_size) (tree);
 393
 394   /* Update lang specific fields after duplicating function body.  */
 395   void (*update_decl_after_saving) (tree, void *);
 396
 397   /* Pointers to machine-independent attribute tables, for front ends
 398      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 399      table of attributes specific to the language, a table of
 400      attributes common to two or more languages (to allow easy
 401      sharing), and a table of attributes for checking formats.  */
 402   const struct attribute_spec *attribute_table;
 403   const struct attribute_spec *common_attribute_table;
 404   const struct attribute_spec *format_attribute_table;
 405
 406   /* Function-related language hooks.  */
 407   struct lang_hooks_for_functions function;
 408
 409   struct lang_hooks_for_tree_inlining tree_inlining;
 410
 411   struct lang_hooks_for_callgraph callgraph;
 412
 413   struct lang_hooks_for_tree_dump tree_dump;
 414
 415   struct lang_hooks_for_decls decls;
 416
 417   struct lang_hooks_for_types types;
 418
 419   /* Perform language-specific gimplification on the argument.  Returns an
 420      enum gimplify_status, though we can't see that type here.  */
 421   int (*gimplify_expr) (tree *, tree *, tree *);
 422
 423   /* True if the front end has gimplified the function before running the
 424      inliner, false if the front end generates GENERIC directly.  */
 425   bool gimple_before_inlining;
 426
 427   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 428      and langhooks.c accordingly.  */
 429 };
 430
 431 /* Each front end provides its own.  */
 432 extern const struct lang_hooks lang_hooks;
 433
 434 #endif /* GCC_LANG_HOOKS_H */