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
  81 /* Lang hooks for rtl code generation.  */
  82 struct lang_hooks_for_rtl_expansion
  83 {
  84   /* Called after expand_function_start, but before expanding the body.  */
  85   void (*start) (void);
  86
  87   /* Called to expand each statement.  */
  88   void (*stmt) (tree);
  89
  90   /* Called after expanding the body but before expand_function_end.  */
  91   void (*end) (void);
  92 };
  93
  94 /* The following hooks are used by tree-dump.c.  */
  95
  96 struct lang_hooks_for_tree_dump
  97 {
  98   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  99      does not want the usual dumping of the second argument.  */
 100   bool (*dump_tree) (void *, tree);
 101
 102   /* Determine type qualifiers in a language-specific way.  */
 103   int (*type_quals) (tree);
 104 };
 105
 106 /* Hooks related to types.  */
 107
 108 struct lang_hooks_for_types
 109 {
 110   /* Return a new type (with the indicated CODE), doing whatever
 111      language-specific processing is required.  */
 112   tree (*make_type) (enum tree_code);
 113
 114   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 115      mode.  */
 116   tree (*type_for_mode) (enum machine_mode, int);
 117
 118   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 119      integer type with at least that precision.  */
 120   tree (*type_for_size) (unsigned, int);
 121
 122   /* Given an integer type T, return a type like T but unsigned.
 123      If T is unsigned, the value is T.  */
 124   tree (*unsigned_type) (tree);
 125
 126   /* Given an integer type T, return a type like T but signed.
 127      If T is signed, the value is T.  */
 128   tree (*signed_type) (tree);
 129
 130   /* Return a type the same as TYPE except unsigned or signed
 131      according to UNSIGNEDP.  */
 132   tree (*signed_or_unsigned_type) (int, tree);
 133
 134   /* Given a type, apply default promotions to unnamed function
 135      arguments and return the new type.  Return the same type if no
 136      change.  Required by any language that supports variadic
 137      arguments.  The default hook aborts.  */
 138   tree (*type_promotes_to) (tree);
 139
 140   /* Register TYPE as a builtin type with the indicated NAME.  The
 141      TYPE is placed in the outermost lexical scope.  The semantics
 142      should be analogous to:
 143
 144        typedef TYPE NAME;
 145
 146      in C.  The default hook ignores the declaration.  */
 147   void (*register_builtin_type) (tree, const char *);
 148
 149   /* This routine is called in tree.c to print an error message for
 150      invalid use of an incomplete type.  VALUE is the expression that
 151      was used (or 0 if that isn't known) and TYPE is the type that was
 152      invalid.  */
 153   void (*incomplete_type_error) (tree value, tree type);
 154 };
 155
 156 /* Language hooks related to decls and the symbol table.  */
 157
 158 struct lang_hooks_for_decls
 159 {
 160   /* Enter a new lexical scope.  Argument is always zero when called
 161      from outside the front end.  */
 162   void (*pushlevel) (int);
 163
 164   /* Exit a lexical scope and return a BINDING for that scope.
 165      Takes three arguments:
 166      KEEP -- nonzero if there were declarations in this scope.
 167      REVERSE -- reverse the order of decls before returning them.
 168      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 169   tree (*poplevel) (int, int, int);
 170
 171   /* Returns nonzero if we are in the global binding level.  Ada
 172      returns -1 for an undocumented reason used in stor-layout.c.  */
 173   int (*global_bindings_p) (void);
 174
 175   /* Insert BLOCK at the end of the list of subblocks of the
 176      current binding level.  This is used when a BIND_EXPR is expanded,
 177      to handle the BLOCK node inside the BIND_EXPR.  */
 178   void (*insert_block) (tree);
 179
 180   /* Set the BLOCK node for the current scope level.  */
 181   void (*set_block) (tree);
 182
 183   /* Function to add a decl to the current scope level.  Takes one
 184      argument, a decl to add.  Returns that decl, or, if the same
 185      symbol is already declared, may return a different decl for that
 186      name.  */
 187   tree (*pushdecl) (tree);
 188
 189   /* Returns the chain of decls so far in the current scope level.  */
 190   tree (*getdecls) (void);
 191
 192   /* Returns true when we should warn for an unused global DECL.
 193      We will already have checked that it has static binding.  */
 194   bool (*warn_unused_global) (tree);
 195
 196   /* Obtain a list of globals and do final output on them at end
 197      of compilation */
 198   void (*final_write_globals) (void);
 199
 200   /* Do necessary preparations before assemble_variable can proceed.  */
 201   void (*prepare_assemble_variable) (tree);
 202
 203   /* True if this decl may be called via a sibcall.  */
 204   bool (*ok_for_sibcall) (tree);
 205 };
 206
 207 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 208
 209 struct lang_hooks
 210 {
 211   /* String identifying the front end.  e.g. "GNU C++".  */
 212   const char *name;
 213
 214   /* sizeof (struct lang_identifier), so make_node () creates
 215      identifier nodes long enough for the language-specific slots.  */
 216   size_t identifier_size;
 217
 218   /* Determines the size of any language-specific 'x' or 'c' nodes.
 219      Since it is called from make_node, the only information available
 220      is the tree code.  Expected to abort on unrecognized codes.  */
 221   size_t (*tree_size) (enum tree_code);
 222
 223   /* The first callback made to the front end, for simple
 224      initialization needed before any calls to handle_option.  Return
 225      the language mask to filter the switch array with.  */
 226   unsigned int (*init_options) (unsigned int argc, const char **argv);
 227
 228   /* Callback used to perform language-specific initialization for the
 229      global diagnostic context structure.  */
 230   void (*initialize_diagnostics) (struct diagnostic_context *);
 231
 232   /* Handle the switch CODE, which has real type enum opt_code from
 233      options.h.  If the switch takes an argument, it is passed in ARG
 234      which points to permanent storage.  The handler is responsible for
 235      checking whether ARG is NULL, which indicates that no argument
 236      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 237      for the positive and negative forms respectively.
 238
 239      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 240      valid and should not be treated as language-independent too.  */
 241   int (*handle_option) (size_t code, const char *arg, int value);
 242
 243   /* Return false to use the default complaint about a missing
 244      argument, otherwise output a complaint and return true.  */
 245   bool (*missing_argument) (const char *opt, size_t code);
 246
 247   /* Called when all command line options have been parsed to allow
 248      further processing and initialization
 249
 250      Should return true to indicate that a compiler back-end is
 251      not required, such as with the -E option.
 252
 253      If errorcount is nonzero after this call the compiler exits
 254      immediately and the finish hook is not called.  */
 255   bool (*post_options) (const char **);
 256
 257   /* Called after post_options to initialize the front end.  Return
 258      false to indicate that no further compilation be performed, in
 259      which case the finish hook is called immediately.  */
 260   bool (*init) (void);
 261
 262   /* Called at the end of compilation, as a finalizer.  */
 263   void (*finish) (void);
 264
 265   /* Parses the entire file.  The argument is nonzero to cause bison
 266      parsers to dump debugging information during parsing.  */
 267   void (*parse_file) (int);
 268
 269   /* Called immediately after parsing to clear the binding stack.  */
 270   void (*clear_binding_stack) (void);
 271
 272   /* Called to obtain the alias set to be used for an expression or type.
 273      Returns -1 if the language does nothing special for it.  */
 274   HOST_WIDE_INT (*get_alias_set) (tree);
 275
 276   /* Called with an expression that is to be processed as a constant.
 277      Returns either the same expression or a language-independent
 278      constant equivalent to its input.  */
 279   tree (*expand_constant) (tree);
 280
 281   /* Called by expand_expr for language-specific tree codes.
 282      Fourth argument is actually an enum expand_modifier.  */
 283   rtx (*expand_expr) (tree, rtx, enum machine_mode, int, rtx *);
 284
 285   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 286      operation.
 287
 288      This preparation consists of taking the ordinary representation
 289      of an expression expr and producing a valid tree boolean
 290      expression describing whether expr is nonzero.  We could simply
 291      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 292      but we optimize comparisons, &&, ||, and !.
 293
 294      The result should be an expression of boolean type (if not an
 295      error_mark_node).  */
 296   tree (*truthvalue_conversion) (tree);
 297
 298   /* Hook called by safe_from_p for language-specific tree codes.  It is
 299      up to the language front-end to install a hook if it has any such
 300      codes that safe_from_p needs to know about.  Since same_from_p will
 301      recursively explore the TREE_OPERANDs of an expression, this hook
 302      should not reexamine those pieces.  This routine may recursively
 303      call safe_from_p; it should always pass `0' as the TOP_P
 304      parameter.  */
 305   int (*safe_from_p) (rtx, tree);
 306
 307   /* Function to finish handling an incomplete decl at the end of
 308      compilation.  Default hook is does nothing.  */
 309   void (*finish_incomplete_decl) (tree);
 310
 311   /* Function used by unsafe_for_reeval.  A non-negative number is
 312      returned directly from unsafe_for_reeval, a negative number falls
 313      through.  The default hook returns a negative number.  */
 314   int (*unsafe_for_reeval) (tree);
 315
 316   /* Mark EXP saying that we need to be able to take the address of
 317      it; it should not be allocated in a register.  Return true if
 318      successful.  */
 319   bool (*mark_addressable) (tree);
 320
 321   /* Hook called by staticp for language-specific tree codes.  */
 322   int (*staticp) (tree);
 323
 324   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 325      DECL_NODE with a newly GC-allocated copy.  */
 326   void (*dup_lang_specific_decl) (tree);
 327
 328   /* Called before its argument, an UNSAVE_EXPR, is to be
 329      unsaved.  Modify it in-place so that all the evaluate only once
 330      things are cleared out.  */
 331   tree (*unsave_expr_now) (tree);
 332
 333   /* Called by expand_expr to build and return the cleanup-expression
 334      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 335   tree (*maybe_build_cleanup) (tree);
 336
 337   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 338      thing that the assembler should talk about, set
 339      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 340      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 341      assembler does not talk about it.  */
 342   void (*set_decl_assembler_name) (tree);
 343
 344   /* Return nonzero if fold-const is free to use bit-field
 345      optimizations, for instance in fold_truthop().  */
 346   bool (*can_use_bit_fields_p) (void);
 347
 348   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 349   bool honor_readonly;
 350
 351   /* Nonzero if this front end does not generate a dummy BLOCK between
 352      the outermost scope of the function and the FUNCTION_DECL.  See
 353      is_body_block in stmt.c, and its callers.  */
 354   bool no_body_blocks;
 355
 356   /* The front end can add its own statistics to -fmem-report with
 357      this hook.  It should output to stderr.  */
 358   void (*print_statistics) (void);
 359
 360   /* Called by print_tree when there is a tree of class 'x' that it
 361      doesn't know how to display.  */
 362   lang_print_tree_hook print_xnode;
 363
 364   /* Called to print language-dependent parts of a class 'd', class
 365      't', and IDENTIFIER_NODE nodes.  */
 366   lang_print_tree_hook print_decl;
 367   lang_print_tree_hook print_type;
 368   lang_print_tree_hook print_identifier;
 369
 370   /* Computes the name to use to print a declaration.  DECL is the
 371      non-NULL declaration in question.  VERBOSITY determines what
 372      information will be printed: 0: DECL_NAME, demangled as
 373      necessary.  1: and scope information.  2: and any other
 374      information that might be interesting, such as function parameter
 375      types in C++.  */
 376   const char *(*decl_printable_name) (tree decl, int verbosity);
 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   /* Called from uninitialized_vars_warning to find out if a variable is
 391      uninitialized based on DECL_INITIAL.  */
 392   bool (*decl_uninit) (tree);
 393
 394   /* Pointers to machine-independent attribute tables, for front ends
 395      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 396      table of attributes specific to the language, a table of
 397      attributes common to two or more languages (to allow easy
 398      sharing), and a table of attributes for checking formats.  */
 399   const struct attribute_spec *attribute_table;
 400   const struct attribute_spec *common_attribute_table;
 401   const struct attribute_spec *format_attribute_table;
 402
 403   /* Function-related language hooks.  */
 404   struct lang_hooks_for_functions function;
 405
 406   struct lang_hooks_for_tree_inlining tree_inlining;
 407
 408   struct lang_hooks_for_callgraph callgraph;
 409
 410   struct lang_hooks_for_tree_dump tree_dump;
 411
 412   struct lang_hooks_for_decls decls;
 413
 414   struct lang_hooks_for_types types;
 415
 416   struct lang_hooks_for_rtl_expansion rtl_expand;
 417
 418   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 419      and langhooks.c accordingly.  */
 420 };
 421
 422 /* Each front end provides its own.  */
 423 extern const struct lang_hooks lang_hooks;
 424
 425 #endif /* GCC_LANG_HOOKS_H */