gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003 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   union tree_node *(*walk_subtrees) (union tree_node **, int *,
  37                                      union tree_node *(*)
  38                                      (union tree_node **, int *, void *),
  39                                      void *, void *);
  40   int (*cannot_inline_tree_fn) (union tree_node **);
  41   int (*disregard_inline_limits) (union tree_node *);
  42   union tree_node *(*add_pending_fn_decls) (void *, union tree_node *);
  43   int (*tree_chain_matters_p) (union tree_node *);
  44   int (*auto_var_in_fn_p) (union tree_node *, union tree_node *);
  45   union tree_node *(*copy_res_decl_for_inlining) (union tree_node *,
  46                                                   union tree_node *,
  47                                                   union tree_node *,
  48                                                   void *, int *, tree);
  49   int (*anon_aggr_type_p) (union tree_node *);
  50   bool (*var_mod_type_p) (union tree_node *);
  51   int (*start_inlining) (union tree_node *);
  52   void (*end_inlining) (union tree_node *);
  53   union tree_node *(*convert_parm_for_inlining) (union tree_node *,
  54                                                  union tree_node *,
  55                                                  union tree_node *);
  56   int (*estimate_num_insns) (union tree_node *);
  57 };
  58
  59 struct lang_hooks_for_callgraph
  60 {
  61   /* Function passed as argument is needed and will be compiled.
  62      Lower the representation so the calls are explicit.  */
  63   void (*lower_function) (union tree_node *);
  64   /* Produce RTL for function passed as argument.  */
  65   void (*expand_function) (union tree_node *);
  66 };
  67
  68 /* Lang hooks for management of language-specific data or status
  69    when entering / leaving functions etc.  */
  70 struct lang_hooks_for_functions
  71 {
  72   /* Called when entering a function.  */
  73   void (*init) (struct function *);
  74
  75   /* Called when leaving a function.  */
  76   void (*final) (struct function *);
  77
  78   /* Called when entering a nested function.  */
  79   void (*enter_nested) (struct function *);
  80
  81   /* Called when leaving a nested function.  */
  82   void (*leave_nested) (struct function *);
  83 };
  84
  85 /* The following hooks are used by tree-dump.c.  */
  86
  87 struct lang_hooks_for_tree_dump
  88 {
  89   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  90      does not want the usual dumping of the second argument.  */
  91   bool (*dump_tree) (void *, tree);
  92
  93   /* Determine type qualifiers in a language-specific way.  */
  94   int (*type_quals) (tree);
  95 };
  96
  97 /* Hooks related to types.  */
  98
  99 struct lang_hooks_for_types
 100 {
 101   /* Return a new type (with the indicated CODE), doing whatever
 102      language-specific processing is required.  */
 103   tree (*make_type) (enum tree_code);
 104
 105   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 106      mode.  */
 107   tree (*type_for_mode) (enum machine_mode, int);
 108
 109   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 110      integer type with at least that precision.  */
 111   tree (*type_for_size) (unsigned, int);
 112
 113   /* Given an integer type T, return a type like T but unsigned.
 114      If T is unsigned, the value is T.  */
 115   tree (*unsigned_type) (tree);
 116
 117   /* Given an integer type T, return a type like T but signed.
 118      If T is signed, the value is T.  */
 119   tree (*signed_type) (tree);
 120
 121   /* Return a type the same as TYPE except unsigned or signed
 122      according to UNSIGNEDP.  */
 123   tree (*signed_or_unsigned_type) (int, tree);
 124
 125   /* Given a type, apply default promotions to unnamed function
 126      arguments and return the new type.  Return the same type if no
 127      change.  Required by any language that supports variadic
 128      arguments.  The default hook aborts.  */
 129   tree (*type_promotes_to) (tree);
 130
 131   /* This routine is called in tree.c to print an error message for
 132      invalid use of an incomplete type.  VALUE is the expression that
 133      was used (or 0 if that isn't known) and TYPE is the type that was
 134      invalid.  */
 135   void (*incomplete_type_error) (tree value, tree type);
 136 };
 137
 138 /* Language hooks related to decls and the symbol table.  */
 139
 140 struct lang_hooks_for_decls
 141 {
 142   /* Enter a new lexical scope.  Argument is always zero when called
 143      from outside the front end.  */
 144   void (*pushlevel) (int);
 145
 146   /* Exit a lexical scope and return a BINDING for that scope.
 147      Takes three arguments:
 148      KEEP -- nonzero if there were declarations in this scope.
 149      REVERSE -- reverse the order of decls before returning them.
 150      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 151   tree (*poplevel) (int, int, int);
 152
 153   /* Returns nonzero if we are in the global binding level.  Ada
 154      returns -1 for an undocumented reason used in stor-layout.c.  */
 155   int (*global_bindings_p) (void);
 156
 157   /* Insert BLOCK at the end of the list of subblocks of the
 158      current binding level.  This is used when a BIND_EXPR is expanded,
 159      to handle the BLOCK node inside the BIND_EXPR.  */
 160   void (*insert_block) (tree);
 161
 162   /* Set the BLOCK node for the current scope level.  */
 163   void (*set_block) (tree);
 164
 165   /* Function to add a decl to the current scope level.  Takes one
 166      argument, a decl to add.  Returns that decl, or, if the same
 167      symbol is already declared, may return a different decl for that
 168      name.  */
 169   tree (*pushdecl) (tree);
 170
 171   /* Returns the chain of decls so far in the current scope level.  */
 172   tree (*getdecls) (void);
 173
 174   /* Returns true when we should warn for an unused global DECL.
 175      We will already have checked that it has static binding.  */
 176   bool (*warn_unused_global) (tree);
 177
 178   /* Obtain a list of globals and do final output on them at end
 179      of compilation */
 180   void (*final_write_globals) (void);
 181
 182   /* Do necessary preparations before assemble_variable can proceed.  */
 183   void (*prepare_assemble_variable) (tree);
 184
 185   /* True if this decl may be called via a sibcall.  */
 186   bool (*ok_for_sibcall) (tree);
 187 };
 188
 189 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 190
 191 struct lang_hooks
 192 {
 193   /* String identifying the front end.  e.g. "GNU C++".  */
 194   const char *name;
 195
 196   /* sizeof (struct lang_identifier), so make_node () creates
 197      identifier nodes long enough for the language-specific slots.  */
 198   size_t identifier_size;
 199
 200   /* Determines the size of any language-specific 'x' or 'c' nodes.
 201      Since it is called from make_node, the only information available
 202      is the tree code.  Expected to abort on unrecognized codes.  */
 203   size_t (*tree_size) (enum tree_code);
 204
 205   /* The first callback made to the front end, for simple
 206      initialization needed before any calls to handle_option.  Return
 207      the language mask to filter the switch array with.  */
 208   unsigned int (*init_options) (unsigned int argc, const char **argv);
 209
 210   /* Handle the switch CODE, which has real type enum opt_code from
 211      options.h.  If the switch takes an argument, it is passed in ARG
 212      which points to permanent storage.  The handler is responsible for
 213      checking whether ARG is NULL, which indicates that no argument
 214      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 215      for the positive and negative forms respectively.
 216
 217      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 218      valid and should not be treated as language-independent too.  */
 219   int (*handle_option) (size_t code, const char *arg, int value);
 220
 221   /* Handle a filename on the command line.  */
 222   void (*handle_filename) (const char *filename);
 223
 224   /* Return false to use the default complaint about a missing
 225      argument, otherwise output a complaint and return true.  */
 226   bool (*missing_argument) (const char *opt, size_t code);
 227
 228   /* Called when all command line options have been parsed to allow
 229      further processing and initialization
 230
 231      Should return true to indicate that a compiler back-end is
 232      not required, such as with the -E option.
 233
 234      If errorcount is nonzero after this call the compiler exits
 235      immediately and the finish hook is not called.  */
 236   bool (*post_options) (const char **);
 237
 238   /* Called after post_options to initialize the front end.  Return
 239      false to indicate that no further compilation be performed, in
 240      which case the finish hook is called immediately.  */
 241   bool (*init) (void);
 242
 243   /* Called at the end of compilation, as a finalizer.  */
 244   void (*finish) (void);
 245
 246   /* Parses the entire file.  The argument is nonzero to cause bison
 247      parsers to dump debugging information during parsing.  */
 248   void (*parse_file) (int);
 249
 250   /* Called immediately after parsing to clear the binding stack.  */
 251   void (*clear_binding_stack) (void);
 252
 253   /* Called to obtain the alias set to be used for an expression or type.
 254      Returns -1 if the language does nothing special for it.  */
 255   HOST_WIDE_INT (*get_alias_set) (tree);
 256
 257   /* Called with an expression that is to be processed as a constant.
 258      Returns either the same expression or a language-independent
 259      constant equivalent to its input.  */
 260   tree (*expand_constant) (tree);
 261
 262   /* Called by expand_expr for language-specific tree codes.
 263      Fourth argument is actually an enum expand_modifier.  */
 264   rtx (*expand_expr) (tree, rtx, enum machine_mode, int);
 265
 266   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 267      operation.
 268
 269      This preparation consists of taking the ordinary representation
 270      of an expression expr and producing a valid tree boolean
 271      expression describing whether expr is nonzero.  We could simply
 272      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 273      but we optimize comparisons, &&, ||, and !.
 274
 275      The result should be an expression of boolean type (if not an
 276      error_mark_node).  */
 277   tree (*truthvalue_conversion) (tree);
 278
 279   /* Possibly apply default attributes to a function (represented by
 280      a FUNCTION_DECL).  */
 281   void (*insert_default_attributes) (tree);
 282
 283   /* Hook called by safe_from_p for language-specific tree codes.  It is
 284      up to the language front-end to install a hook if it has any such
 285      codes that safe_from_p needs to know about.  Since same_from_p will
 286      recursively explore the TREE_OPERANDs of an expression, this hook
 287      should not reexamine those pieces.  This routine may recursively
 288      call safe_from_p; it should always pass `0' as the TOP_P
 289      parameter.  */
 290   int (*safe_from_p) (rtx, tree);
 291
 292   /* Function to finish handling an incomplete decl at the end of
 293      compilation.  Default hook is does nothing.  */
 294   void (*finish_incomplete_decl) (tree);
 295
 296   /* Function used by unsafe_for_reeval.  A non-negative number is
 297      returned directly from unsafe_for_reeval, a negative number falls
 298      through.  The default hook returns a negative number.  */
 299   int (*unsafe_for_reeval) (tree);
 300
 301   /* Mark EXP saying that we need to be able to take the address of
 302      it; it should not be allocated in a register.  Return true if
 303      successful.  */
 304   bool (*mark_addressable) (tree);
 305
 306   /* Hook called by staticp for language-specific tree codes.  */
 307   int (*staticp) (tree);
 308
 309   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 310      DECL_NODE with a newly GC-allocated copy.  */
 311   void (*dup_lang_specific_decl) (tree);
 312
 313   /* Called before its argument, an UNSAVE_EXPR, is to be
 314      unsaved.  Modify it in-place so that all the evaluate only once
 315      things are cleared out.  */
 316   tree (*unsave_expr_now) (tree);
 317
 318   /* Called by expand_expr to build and return the cleanup-expression
 319      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 320   tree (*maybe_build_cleanup) (tree);
 321
 322   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 323      thing that the assembler should talk about, set
 324      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 325      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 326      assembler does not talk about it.  */
 327   void (*set_decl_assembler_name) (tree);
 328
 329   /* Return nonzero if fold-const is free to use bit-field
 330      optimizations, for instance in fold_truthop().  */
 331   bool (*can_use_bit_fields_p) (void);
 332
 333   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 334   bool honor_readonly;
 335
 336   /* Nonzero if this front end does not generate a dummy BLOCK between
 337      the outermost scope of the function and the FUNCTION_DECL.  See
 338      is_body_block in stmt.c, and its callers.  */
 339   bool no_body_blocks;
 340
 341   /* The front end can add its own statistics to -fmem-report with
 342      this hook.  It should output to stderr.  */
 343   void (*print_statistics) (void);
 344
 345   /* Called by print_tree when there is a tree of class 'x' that it
 346      doesn't know how to display.  */
 347   lang_print_tree_hook print_xnode;
 348
 349   /* Called to print language-dependent parts of a class 'd', class
 350      't', and IDENTIFIER_NODE nodes.  */
 351   lang_print_tree_hook print_decl;
 352   lang_print_tree_hook print_type;
 353   lang_print_tree_hook print_identifier;
 354
 355   /* Computes the name to use to print a declaration.  DECL is the
 356      non-NULL declaration in question.  VERBOSITY determines what
 357      information will be printed: 0: DECL_NAME, demangled as
 358      necessary.  1: and scope information.  2: and any other
 359      information that might be interesting, such as function parameter
 360      types in C++.  */
 361   const char *(*decl_printable_name) (tree decl, int verbosity);
 362
 363   /* Called by report_error_function to print out function name.  */
 364   void (*print_error_function) (struct diagnostic_context *, const char *);
 365
 366   /* Called from expr_size to calculate the size of the value of an
 367      expression in a language-dependent way.  Returns a tree for the size
 368      in bytes.  A frontend can call lhd_expr_size to get the default
 369      semantics in cases that it doesn't want to handle specially.  */
 370   tree (*expr_size) (tree);
 371
 372   /* Pointers to machine-independent attribute tables, for front ends
 373      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 374      table of attributes specific to the language, a table of
 375      attributes common to two or more languages (to allow easy
 376      sharing), and a table of attributes for checking formats.  */
 377   const struct attribute_spec *attribute_table;
 378   const struct attribute_spec *common_attribute_table;
 379   const struct attribute_spec *format_attribute_table;
 380
 381   /* Function-related language hooks.  */
 382   struct lang_hooks_for_functions function;
 383
 384   struct lang_hooks_for_tree_inlining tree_inlining;
 385
 386   struct lang_hooks_for_callgraph callgraph;
 387
 388   struct lang_hooks_for_tree_dump tree_dump;
 389
 390   struct lang_hooks_for_decls decls;
 391
 392   struct lang_hooks_for_types types;
 393
 394   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 395      and langhooks.c accordingly.  */
 396 };
 397
 398 /* Each front end provides its own.  */
 399 extern const struct lang_hooks lang_hooks;
 400
 401 #endif /* GCC_LANG_HOOKS_H */