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   /* Function passed as argument is needed and will be compiled.
  57      Lower the representation so the calls are explicit.  */
  58   void (*lower_function) (tree);
  59   /* Produce RTL for function passed as argument.  */
  60   void (*expand_function) (tree);
  61 };
  62
  63 /* Lang hooks for management of language-specific data or status
  64    when entering / leaving functions etc.  */
  65 struct lang_hooks_for_functions
  66 {
  67   /* Called when entering a function.  */
  68   void (*init) (struct function *);
  69
  70   /* Called when leaving a function.  */
  71   void (*final) (struct function *);
  72
  73   /* Called when entering a nested function.  */
  74   void (*enter_nested) (struct function *);
  75
  76   /* Called when leaving a nested function.  */
  77   void (*leave_nested) (struct function *);
  78 };
  79
  80 /* Lang hooks for rtl code generation.  */
  81 struct lang_hooks_for_rtl_expansion
  82 {
  83   /* Called after expand_function_start, but before expanding the body.  */
  84   void (*start) (void);
  85
  86   /* Called to expand each statement.  */
  87   void (*stmt) (tree);
  88
  89   /* Called after expanding the body but before expand_function_end.  */
  90   void (*end) (void);
  91 };
  92
  93 /* The following hooks are used by tree-dump.c.  */
  94
  95 struct lang_hooks_for_tree_dump
  96 {
  97   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  98      does not want the usual dumping of the second argument.  */
  99   bool (*dump_tree) (void *, tree);
 100
 101   /* Determine type qualifiers in a language-specific way.  */
 102   int (*type_quals) (tree);
 103 };
 104
 105 /* Hooks related to types.  */
 106
 107 struct lang_hooks_for_types
 108 {
 109   /* Return a new type (with the indicated CODE), doing whatever
 110      language-specific processing is required.  */
 111   tree (*make_type) (enum tree_code);
 112
 113   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 114      mode.  */
 115   tree (*type_for_mode) (enum machine_mode, int);
 116
 117   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 118      integer type with at least that precision.  */
 119   tree (*type_for_size) (unsigned, int);
 120
 121   /* Given an integer type T, return a type like T but unsigned.
 122      If T is unsigned, the value is T.  */
 123   tree (*unsigned_type) (tree);
 124
 125   /* Given an integer type T, return a type like T but signed.
 126      If T is signed, the value is T.  */
 127   tree (*signed_type) (tree);
 128
 129   /* Return a type the same as TYPE except unsigned or signed
 130      according to UNSIGNEDP.  */
 131   tree (*signed_or_unsigned_type) (int, tree);
 132
 133   /* Given a type, apply default promotions to unnamed function
 134      arguments and return the new type.  Return the same type if no
 135      change.  Required by any language that supports variadic
 136      arguments.  The default hook aborts.  */
 137   tree (*type_promotes_to) (tree);
 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
 146 /* Language hooks related to decls and the symbol table.  */
 147
 148 struct lang_hooks_for_decls
 149 {
 150   /* Enter a new lexical scope.  Argument is always zero when called
 151      from outside the front end.  */
 152   void (*pushlevel) (int);
 153
 154   /* Exit a lexical scope and return a BINDING for that scope.
 155      Takes three arguments:
 156      KEEP -- nonzero if there were declarations in this scope.
 157      REVERSE -- reverse the order of decls before returning them.
 158      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 159   tree (*poplevel) (int, int, int);
 160
 161   /* Returns nonzero if we are in the global binding level.  Ada
 162      returns -1 for an undocumented reason used in stor-layout.c.  */
 163   int (*global_bindings_p) (void);
 164
 165   /* Insert BLOCK at the end of the list of subblocks of the
 166      current binding level.  This is used when a BIND_EXPR is expanded,
 167      to handle the BLOCK node inside the BIND_EXPR.  */
 168   void (*insert_block) (tree);
 169
 170   /* Set the BLOCK node for the current scope level.  */
 171   void (*set_block) (tree);
 172
 173   /* Function to add a decl to the current scope level.  Takes one
 174      argument, a decl to add.  Returns that decl, or, if the same
 175      symbol is already declared, may return a different decl for that
 176      name.  */
 177   tree (*pushdecl) (tree);
 178
 179   /* Returns the chain of decls so far in the current scope level.  */
 180   tree (*getdecls) (void);
 181
 182   /* Returns true when we should warn for an unused global DECL.
 183      We will already have checked that it has static binding.  */
 184   bool (*warn_unused_global) (tree);
 185
 186   /* Obtain a list of globals and do final output on them at end
 187      of compilation */
 188   void (*final_write_globals) (void);
 189
 190   /* Do necessary preparations before assemble_variable can proceed.  */
 191   void (*prepare_assemble_variable) (tree);
 192
 193   /* True if this decl may be called via a sibcall.  */
 194   bool (*ok_for_sibcall) (tree);
 195 };
 196
 197 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 198
 199 struct lang_hooks
 200 {
 201   /* String identifying the front end.  e.g. "GNU C++".  */
 202   const char *name;
 203
 204   /* sizeof (struct lang_identifier), so make_node () creates
 205      identifier nodes long enough for the language-specific slots.  */
 206   size_t identifier_size;
 207
 208   /* Determines the size of any language-specific 'x' or 'c' nodes.
 209      Since it is called from make_node, the only information available
 210      is the tree code.  Expected to abort on unrecognized codes.  */
 211   size_t (*tree_size) (enum tree_code);
 212
 213   /* The first callback made to the front end, for simple
 214      initialization needed before any calls to handle_option.  Return
 215      the language mask to filter the switch array with.  */
 216   unsigned int (*init_options) (unsigned int argc, const char **argv);
 217
 218   /* Callback used to perform language-specific initialization for the
 219      global diagnostic context structure.  */
 220   void (*initialize_diagnostics) (struct diagnostic_context *);
 221
 222   /* Handle the switch CODE, which has real type enum opt_code from
 223      options.h.  If the switch takes an argument, it is passed in ARG
 224      which points to permanent storage.  The handler is responsible for
 225      checking whether ARG is NULL, which indicates that no argument
 226      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 227      for the positive and negative forms respectively.
 228
 229      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 230      valid and should not be treated as language-independent too.  */
 231   int (*handle_option) (size_t code, const char *arg, int value);
 232
 233   /* Return false to use the default complaint about a missing
 234      argument, otherwise output a complaint and return true.  */
 235   bool (*missing_argument) (const char *opt, size_t code);
 236
 237   /* Called when all command line options have been parsed to allow
 238      further processing and initialization
 239
 240      Should return true to indicate that a compiler back-end is
 241      not required, such as with the -E option.
 242
 243      If errorcount is nonzero after this call the compiler exits
 244      immediately and the finish hook is not called.  */
 245   bool (*post_options) (const char **);
 246
 247   /* Called after post_options to initialize the front end.  Return
 248      false to indicate that no further compilation be performed, in
 249      which case the finish hook is called immediately.  */
 250   bool (*init) (void);
 251
 252   /* Called at the end of compilation, as a finalizer.  */
 253   void (*finish) (void);
 254
 255   /* Parses the entire file.  The argument is nonzero to cause bison
 256      parsers to dump debugging information during parsing.  */
 257   void (*parse_file) (int);
 258
 259   /* Called immediately after parsing to clear the binding stack.  */
 260   void (*clear_binding_stack) (void);
 261
 262   /* Called to obtain the alias set to be used for an expression or type.
 263      Returns -1 if the language does nothing special for it.  */
 264   HOST_WIDE_INT (*get_alias_set) (tree);
 265
 266   /* Called with an expression that is to be processed as a constant.
 267      Returns either the same expression or a language-independent
 268      constant equivalent to its input.  */
 269   tree (*expand_constant) (tree);
 270
 271   /* Called by expand_expr for language-specific tree codes.
 272      Fourth argument is actually an enum expand_modifier.  */
 273   rtx (*expand_expr) (tree, rtx, enum machine_mode, int);
 274
 275   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 276      operation.
 277
 278      This preparation consists of taking the ordinary representation
 279      of an expression expr and producing a valid tree boolean
 280      expression describing whether expr is nonzero.  We could simply
 281      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 282      but we optimize comparisons, &&, ||, and !.
 283
 284      The result should be an expression of boolean type (if not an
 285      error_mark_node).  */
 286   tree (*truthvalue_conversion) (tree);
 287
 288   /* Hook called by safe_from_p for language-specific tree codes.  It is
 289      up to the language front-end to install a hook if it has any such
 290      codes that safe_from_p needs to know about.  Since same_from_p will
 291      recursively explore the TREE_OPERANDs of an expression, this hook
 292      should not reexamine those pieces.  This routine may recursively
 293      call safe_from_p; it should always pass `0' as the TOP_P
 294      parameter.  */
 295   int (*safe_from_p) (rtx, tree);
 296
 297   /* Function to finish handling an incomplete decl at the end of
 298      compilation.  Default hook is does nothing.  */
 299   void (*finish_incomplete_decl) (tree);
 300
 301   /* Function used by unsafe_for_reeval.  A non-negative number is
 302      returned directly from unsafe_for_reeval, a negative number falls
 303      through.  The default hook returns a negative number.  */
 304   int (*unsafe_for_reeval) (tree);
 305
 306   /* Mark EXP saying that we need to be able to take the address of
 307      it; it should not be allocated in a register.  Return true if
 308      successful.  */
 309   bool (*mark_addressable) (tree);
 310
 311   /* Hook called by staticp for language-specific tree codes.  */
 312   int (*staticp) (tree);
 313
 314   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 315      DECL_NODE with a newly GC-allocated copy.  */
 316   void (*dup_lang_specific_decl) (tree);
 317
 318   /* Called before its argument, an UNSAVE_EXPR, is to be
 319      unsaved.  Modify it in-place so that all the evaluate only once
 320      things are cleared out.  */
 321   tree (*unsave_expr_now) (tree);
 322
 323   /* Called by expand_expr to build and return the cleanup-expression
 324      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 325   tree (*maybe_build_cleanup) (tree);
 326
 327   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 328      thing that the assembler should talk about, set
 329      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 330      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 331      assembler does not talk about it.  */
 332   void (*set_decl_assembler_name) (tree);
 333
 334   /* Return nonzero if fold-const is free to use bit-field
 335      optimizations, for instance in fold_truthop().  */
 336   bool (*can_use_bit_fields_p) (void);
 337
 338   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 339   bool honor_readonly;
 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 'x' that it
 351      doesn't know how to display.  */
 352   lang_print_tree_hook print_xnode;
 353
 354   /* Called to print language-dependent parts of a class 'd', class
 355      't', 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   /* Called by report_error_function to print out function name.  */
 369   void (*print_error_function) (struct diagnostic_context *, const char *);
 370
 371   /* Called from expr_size to calculate the size of the value of an
 372      expression in a language-dependent way.  Returns a tree for the size
 373      in bytes.  A frontend can call lhd_expr_size to get the default
 374      semantics in cases that it doesn't want to handle specially.  */
 375   tree (*expr_size) (tree);
 376
 377   /* Called from uninitialized_vars_warning to find out if a variable is
 378      uninitialized based on DECL_INITIAL.  */
 379   bool (*decl_uninit) (tree);
 380
 381   /* Pointers to machine-independent attribute tables, for front ends
 382      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 383      table of attributes specific to the language, a table of
 384      attributes common to two or more languages (to allow easy
 385      sharing), and a table of attributes for checking formats.  */
 386   const struct attribute_spec *attribute_table;
 387   const struct attribute_spec *common_attribute_table;
 388   const struct attribute_spec *format_attribute_table;
 389
 390   /* Function-related language hooks.  */
 391   struct lang_hooks_for_functions function;
 392
 393   struct lang_hooks_for_tree_inlining tree_inlining;
 394
 395   struct lang_hooks_for_callgraph callgraph;
 396
 397   struct lang_hooks_for_tree_dump tree_dump;
 398
 399   struct lang_hooks_for_decls decls;
 400
 401   struct lang_hooks_for_types types;
 402
 403   struct lang_hooks_for_rtl_expansion rtl_expand;
 404
 405   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 406      and langhooks.c accordingly.  */
 407 };
 408
 409 /* Each front end provides its own.  */
 410 extern const struct lang_hooks lang_hooks;
 411
 412 #endif /* GCC_LANG_HOOKS_H */