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   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);
  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 a chain of TYPE_DECLs for built-in types.  */
 193   tree (*builtin_type_decls) (void);
 194
 195   /* Returns true when we should warn for an unused global DECL.
 196      We will already have checked that it has static binding.  */
 197   bool (*warn_unused_global) (tree);
 198
 199   /* Obtain a list of globals and do final output on them at end
 200      of compilation */
 201   void (*final_write_globals) (void);
 202
 203   /* Do necessary preparations before assemble_variable can proceed.  */
 204   void (*prepare_assemble_variable) (tree);
 205
 206   /* True if this decl may be called via a sibcall.  */
 207   bool (*ok_for_sibcall) (tree);
 208 };
 209
 210 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 211
 212 struct lang_hooks
 213 {
 214   /* String identifying the front end.  e.g. "GNU C++".  */
 215   const char *name;
 216
 217   /* sizeof (struct lang_identifier), so make_node () creates
 218      identifier nodes long enough for the language-specific slots.  */
 219   size_t identifier_size;
 220
 221   /* Determines the size of any language-specific 'x' or 'c' nodes.
 222      Since it is called from make_node, the only information available
 223      is the tree code.  Expected to abort on unrecognized codes.  */
 224   size_t (*tree_size) (enum tree_code);
 225
 226   /* The first callback made to the front end, for simple
 227      initialization needed before any calls to handle_option.  Return
 228      the language mask to filter the switch array with.  */
 229   unsigned int (*init_options) (unsigned int argc, const char **argv);
 230
 231   /* Callback used to perform language-specific initialization for the
 232      global diagnostic context structure.  */
 233   void (*initialize_diagnostics) (struct diagnostic_context *);
 234
 235   /* Handle the switch CODE, which has real type enum opt_code from
 236      options.h.  If the switch takes an argument, it is passed in ARG
 237      which points to permanent storage.  The handler is responsible for
 238      checking whether ARG is NULL, which indicates that no argument
 239      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 240      for the positive and negative forms respectively.
 241
 242      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 243      valid and should not be treated as language-independent too.  */
 244   int (*handle_option) (size_t code, const char *arg, int value);
 245
 246   /* Return false to use the default complaint about a missing
 247      argument, otherwise output a complaint and return true.  */
 248   bool (*missing_argument) (const char *opt, size_t code);
 249
 250   /* Called when all command line options have been parsed to allow
 251      further processing and initialization
 252
 253      Should return true to indicate that a compiler back-end is
 254      not required, such as with the -E option.
 255
 256      If errorcount is nonzero after this call the compiler exits
 257      immediately and the finish hook is not called.  */
 258   bool (*post_options) (const char **);
 259
 260   /* Called after post_options to initialize the front end.  Return
 261      false to indicate that no further compilation be performed, in
 262      which case the finish hook is called immediately.  */
 263   bool (*init) (void);
 264
 265   /* Called at the end of compilation, as a finalizer.  */
 266   void (*finish) (void);
 267
 268   /* Parses the entire file.  The argument is nonzero to cause bison
 269      parsers to dump debugging information during parsing.  */
 270   void (*parse_file) (int);
 271
 272   /* Called immediately after parsing to clear the binding stack.  */
 273   void (*clear_binding_stack) (void);
 274
 275   /* Called to obtain the alias set to be used for an expression or type.
 276      Returns -1 if the language does nothing special for it.  */
 277   HOST_WIDE_INT (*get_alias_set) (tree);
 278
 279   /* Called with an expression that is to be processed as a constant.
 280      Returns either the same expression or a language-independent
 281      constant equivalent to its input.  */
 282   tree (*expand_constant) (tree);
 283
 284   /* Called by expand_expr for language-specific tree codes.
 285      Fourth argument is actually an enum expand_modifier.  */
 286   rtx (*expand_expr) (tree, rtx, enum machine_mode, int);
 287
 288   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 289      operation.
 290
 291      This preparation consists of taking the ordinary representation
 292      of an expression expr and producing a valid tree boolean
 293      expression describing whether expr is nonzero.  We could simply
 294      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 295      but we optimize comparisons, &&, ||, and !.
 296
 297      The result should be an expression of boolean type (if not an
 298      error_mark_node).  */
 299   tree (*truthvalue_conversion) (tree);
 300
 301   /* Hook called by safe_from_p for language-specific tree codes.  It is
 302      up to the language front-end to install a hook if it has any such
 303      codes that safe_from_p needs to know about.  Since same_from_p will
 304      recursively explore the TREE_OPERANDs of an expression, this hook
 305      should not reexamine those pieces.  This routine may recursively
 306      call safe_from_p; it should always pass `0' as the TOP_P
 307      parameter.  */
 308   int (*safe_from_p) (rtx, tree);
 309
 310   /* Function to finish handling an incomplete decl at the end of
 311      compilation.  Default hook is does nothing.  */
 312   void (*finish_incomplete_decl) (tree);
 313
 314   /* Function used by unsafe_for_reeval.  A non-negative number is
 315      returned directly from unsafe_for_reeval, a negative number falls
 316      through.  The default hook returns a negative number.  */
 317   int (*unsafe_for_reeval) (tree);
 318
 319   /* Mark EXP saying that we need to be able to take the address of
 320      it; it should not be allocated in a register.  Return true if
 321      successful.  */
 322   bool (*mark_addressable) (tree);
 323
 324   /* Hook called by staticp for language-specific tree codes.  */
 325   int (*staticp) (tree);
 326
 327   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 328      DECL_NODE with a newly GC-allocated copy.  */
 329   void (*dup_lang_specific_decl) (tree);
 330
 331   /* Called before its argument, an UNSAVE_EXPR, is to be
 332      unsaved.  Modify it in-place so that all the evaluate only once
 333      things are cleared out.  */
 334   tree (*unsave_expr_now) (tree);
 335
 336   /* Called by expand_expr to build and return the cleanup-expression
 337      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 338   tree (*maybe_build_cleanup) (tree);
 339
 340   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 341      thing that the assembler should talk about, set
 342      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 343      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 344      assembler does not talk about it.  */
 345   void (*set_decl_assembler_name) (tree);
 346
 347   /* Return nonzero if fold-const is free to use bit-field
 348      optimizations, for instance in fold_truthop().  */
 349   bool (*can_use_bit_fields_p) (void);
 350
 351   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 352   bool honor_readonly;
 353
 354   /* Nonzero if this front end does not generate a dummy BLOCK between
 355      the outermost scope of the function and the FUNCTION_DECL.  See
 356      is_body_block in stmt.c, and its callers.  */
 357   bool no_body_blocks;
 358
 359   /* The front end can add its own statistics to -fmem-report with
 360      this hook.  It should output to stderr.  */
 361   void (*print_statistics) (void);
 362
 363   /* Called by print_tree when there is a tree of class 'x' that it
 364      doesn't know how to display.  */
 365   lang_print_tree_hook print_xnode;
 366
 367   /* Called to print language-dependent parts of a class 'd', class
 368      't', and IDENTIFIER_NODE nodes.  */
 369   lang_print_tree_hook print_decl;
 370   lang_print_tree_hook print_type;
 371   lang_print_tree_hook print_identifier;
 372
 373   /* Computes the name to use to print a declaration.  DECL is the
 374      non-NULL declaration in question.  VERBOSITY determines what
 375      information will be printed: 0: DECL_NAME, demangled as
 376      necessary.  1: and scope information.  2: and any other
 377      information that might be interesting, such as function parameter
 378      types in C++.  */
 379   const char *(*decl_printable_name) (tree decl, int verbosity);
 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 */