xref: /openbsd/gnu/usr.bin/gcc/gcc/langhooks.h (revision c87b03e5)
1 /* The lang_hooks data structure.
2    Copyright 2001, 2002 Free Software Foundation, Inc.
3 
4 This file is part of GNU CC.
5 
6 GNU CC 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 GNU CC 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 GNU CC; 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) PARAMS ((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) PARAMS ((union tree_node **, int *,
37 					     union tree_node *(*)
38 					     (union tree_node **,
39 					      int *, void *),
40 					     void *, void *));
41   int (*cannot_inline_tree_fn) PARAMS ((union tree_node **));
42   int (*disregard_inline_limits) PARAMS ((union tree_node *));
43   union tree_node *(*add_pending_fn_decls) PARAMS ((void *,
44 						    union tree_node *));
45   int (*tree_chain_matters_p) PARAMS ((union tree_node *));
46   int (*auto_var_in_fn_p) PARAMS ((union tree_node *, union tree_node *));
47   union tree_node *(*copy_res_decl_for_inlining) PARAMS ((union tree_node *,
48 							  union tree_node *,
49 							  union tree_node *,
50 							  void *, int *,
51 							  void *));
52   int (*anon_aggr_type_p) PARAMS ((union tree_node *));
53   bool (*var_mod_type_p) PARAMS ((union tree_node *));
54   int (*start_inlining) PARAMS ((union tree_node *));
55   void (*end_inlining) PARAMS ((union tree_node *));
56   union tree_node *(*convert_parm_for_inlining) PARAMS ((union tree_node *,
57 							 union tree_node *,
58 							 union tree_node *));
59 };
60 
61 /* Lang hooks for management of language-specific data or status
62    when entering / leaving functions etc.  */
63 struct lang_hooks_for_functions
64 {
65   /* Called when entering a function.  */
66   void (*init) PARAMS ((struct function *));
67 
68   /* Called when leaving a function.  */
69   void (*final) PARAMS ((struct function *));
70 
71   /* Called when entering a nested function.  */
72   void (*enter_nested) PARAMS ((struct function *));
73 
74   /* Called when leaving a nested function.  */
75   void (*leave_nested) PARAMS ((struct function *));
76 };
77 
78 /* The following hooks are used by tree-dump.c.  */
79 
80 struct lang_hooks_for_tree_dump
81 {
82   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
83      does not want the usual dumping of the second argument.  */
84   int (*dump_tree) PARAMS ((void *, tree));
85 
86   /* Determine type qualifiers in a language-specific way.  */
87   int (*type_quals) PARAMS ((tree));
88 };
89 
90 /* Hooks related to types.  */
91 
92 struct lang_hooks_for_types
93 {
94   /* Return a new type (with the indicated CODE), doing whatever
95      language-specific processing is required.  */
96   tree (*make_type) PARAMS ((enum tree_code));
97 
98   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
99      mode.  */
100   tree (*type_for_mode) PARAMS ((enum machine_mode, int));
101 
102   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
103      integer type with at least that precision.  */
104   tree (*type_for_size) PARAMS ((unsigned, int));
105 
106   /* Given an integer type T, return a type like T but unsigned.
107      If T is unsigned, the value is T.  */
108   tree (*unsigned_type) PARAMS ((tree));
109 
110   /* Given an integer type T, return a type like T but signed.
111      If T is signed, the value is T.  */
112   tree (*signed_type) PARAMS ((tree));
113 
114   /* Return a type the same as TYPE except unsigned or signed
115      according to UNSIGNEDP.  */
116   tree (*signed_or_unsigned_type) PARAMS ((int, tree));
117 
118   /* Given a type, apply default promotions to unnamed function
119      arguments and return the new type.  Return the same type if no
120      change.  Required by any language that supports variadic
121      arguments.  The default hook aborts.  */
122   tree (*type_promotes_to) PARAMS ((tree));
123 
124   /* This routine is called in tree.c to print an error message for
125      invalid use of an incomplete type.  VALUE is the expression that
126      was used (or 0 if that isn't known) and TYPE is the type that was
127      invalid.  */
128   void (*incomplete_type_error) PARAMS ((tree value, tree type));
129 };
130 
131 /* Language hooks related to decls and the symbol table.  */
132 
133 struct lang_hooks_for_decls
134 {
135   /* Enter a new lexical scope.  Argument is always zero when called
136      from outside the front end.  */
137   void (*pushlevel) PARAMS ((int));
138 
139   /* Exit a lexical scope and return a BINDING for that scope.
140      Takes three arguments:
141      KEEP -- nonzero if there were declarations in this scope.
142      REVERSE -- reverse the order of decls before returning them.
143      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
144   tree (*poplevel) PARAMS ((int, int, int));
145 
146   /* Returns nonzero if we are in the global binding level.  Ada
147      returns -1 for an undocumented reason used in stor-layout.c.  */
148   int (*global_bindings_p) PARAMS ((void));
149 
150   /* Insert BLOCK at the end of the list of subblocks of the
151      current binding level.  This is used when a BIND_EXPR is expanded,
152      to handle the BLOCK node inside the BIND_EXPR.  */
153   void (*insert_block) PARAMS ((tree));
154 
155   /* Set the BLOCK node for the current scope level.  */
156   void (*set_block) PARAMS ((tree));
157 
158   /* Function to add a decl to the current scope level.  Takes one
159      argument, a decl to add.  Returns that decl, or, if the same
160      symbol is already declared, may return a different decl for that
161      name.  */
162   tree (*pushdecl) PARAMS ((tree));
163 
164   /* Returns the chain of decls so far in the current scope level.  */
165   tree (*getdecls) PARAMS ((void));
166 
167   /* Returns true when we should warn for an unused global DECL.
168      We will already have checked that it has static binding.  */
169   bool (*warn_unused_global) PARAMS ((tree));
170 
171   /* Obtain a list of globals and do final output on them at end
172      of compilation */
173   void (*final_write_globals) PARAMS ((void));
174 
175   /* True if this decl may be called via a sibcall.  */
176   bool (*ok_for_sibcall) PARAMS ((tree));
177 };
178 
179 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
180 
181 struct lang_hooks
182 {
183   /* String identifying the front end.  e.g. "GNU C++".  */
184   const char *name;
185 
186   /* sizeof (struct lang_identifier), so make_node () creates
187      identifier nodes long enough for the language-specific slots.  */
188   size_t identifier_size;
189 
190   /* The first callback made to the front end, for simple
191      initialization needed before any calls to decode_option.  */
192   void (*init_options) PARAMS ((void));
193 
194   /* Function called with an option vector as argument, to decode a
195      single option (typically starting with -f or -W or +).  It should
196      return the number of command-line arguments it uses if it handles
197      the option, or 0 and not complain if it does not recognize the
198      option.  If this function returns a negative number, then its
199      absolute value is the number of command-line arguments used, but,
200      in addition, no language-independent option processing should be
201      done for this option.  */
202   int (*decode_option) PARAMS ((int, char **));
203 
204   /* Called when all command line options have been parsed.  Should do
205      any required consistency checks, modifications etc.  Complex
206      initialization should be left to the "init" callback, since GC
207      and the identifier hashes are set up between now and then.
208 
209      Should return zero unless the compiler back-end does not need to
210      be initialized, such as with the -E option.
211 
212      If errorcount is nonzero after this call the compiler exits
213      immediately and the finish hook is not called.  */
214   bool (*post_options) PARAMS ((void));
215 
216   /* Called after post_options, to initialize the front end.  The main
217      input filename is passed, which may be NULL; the front end should
218      return the original filename (e.g. foo.i -> foo.c).  Return NULL
219      to indicate a serious error of some sort; in that case no
220      compilation is performed, and the finish hook is called
221      immediately.  */
222   const char * (*init) PARAMS ((const char *));
223 
224   /* Called at the end of compilation, as a finalizer.  */
225   void (*finish) PARAMS ((void));
226 
227   /* Parses the entire file.  The argument is nonzero to cause bison
228      parsers to dump debugging information during parsing.  */
229   void (*parse_file) PARAMS ((int));
230 
231   /* Called immediately after parsing to clear the binding stack.  */
232   void (*clear_binding_stack) PARAMS ((void));
233 
234   /* Called to obtain the alias set to be used for an expression or type.
235      Returns -1 if the language does nothing special for it.  */
236   HOST_WIDE_INT (*get_alias_set) PARAMS ((tree));
237 
238   /* Called with an expression that is to be processed as a constant.
239      Returns either the same expression or a language-independent
240      constant equivalent to its input.  */
241   tree (*expand_constant) PARAMS ((tree));
242 
243   /* Called by expand_expr for language-specific tree codes.
244      Fourth argument is actually an enum expand_modifier.  */
245   rtx (*expand_expr) PARAMS ((tree, rtx, enum machine_mode, int));
246 
247   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
248      operation.
249 
250      This preparation consists of taking the ordinary representation
251      of an expression expr and producing a valid tree boolean
252      expression describing whether expr is nonzero.  We could simply
253      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
254      but we optimize comparisons, &&, ||, and !.
255 
256      The result should be an expression of boolean type (if not an
257      error_mark_node).  */
258   tree (*truthvalue_conversion) PARAMS ((tree));
259 
260   /* Possibly apply default attributes to a function (represented by
261      a FUNCTION_DECL).  */
262   void (*insert_default_attributes) PARAMS ((tree));
263 
264   /* Hook called by safe_from_p for language-specific tree codes.  It is
265      up to the language front-end to install a hook if it has any such
266      codes that safe_from_p needs to know about.  Since same_from_p will
267      recursively explore the TREE_OPERANDs of an expression, this hook
268      should not reexamine those pieces.  This routine may recursively
269      call safe_from_p; it should always pass `0' as the TOP_P
270      parameter.  */
271   int (*safe_from_p) PARAMS ((rtx, tree));
272 
273   /* Function to finish handling an incomplete decl at the end of
274      compilation.  Default hook is does nothing.  */
275   void (*finish_incomplete_decl) PARAMS ((tree));
276 
277   /* Function used by unsafe_for_reeval.  A non-negative number is
278      returned directly from unsafe_for_reeval, a negative number falls
279      through.  The default hook returns a negative number.  */
280   int (*unsafe_for_reeval) PARAMS ((tree));
281 
282   /* Mark EXP saying that we need to be able to take the address of
283      it; it should not be allocated in a register.  Return true if
284      successful.  */
285   bool (*mark_addressable) PARAMS ((tree));
286 
287   /* Hook called by staticp for language-specific tree codes.  */
288   int (*staticp) PARAMS ((tree));
289 
290   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
291      DECL_NODE with a newly GC-allocated copy.  */
292   void (*dup_lang_specific_decl) PARAMS ((tree));
293 
294   /* Called before its argument, an UNSAVE_EXPR, is to be
295      unsaved.  Modify it in-place so that all the evaluate only once
296      things are cleared out.  */
297   tree (*unsave_expr_now) PARAMS ((tree));
298 
299   /* Called by expand_expr to build and return the cleanup-expression
300      for the passed TARGET_EXPR.  Return NULL if there is none.  */
301   tree (*maybe_build_cleanup) PARAMS ((tree));
302 
303   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
304      thing that the assembler should talk about, set
305      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
306      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
307      assembler does not talk about it.  */
308   void (*set_decl_assembler_name) PARAMS ((tree));
309 
310   /* Return nonzero if fold-const is free to use bit-field
311      optimizations, for instance in fold_truthop().  */
312   bool (*can_use_bit_fields_p) PARAMS ((void));
313 
314   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
315   bool honor_readonly;
316 
317   /* The front end can add its own statistics to -fmem-report with
318      this hook.  It should output to stderr.  */
319   void (*print_statistics) PARAMS ((void));
320 
321   /* Called by print_tree when there is a tree of class 'x' that it
322      doesn't know how to display.  */
323   lang_print_tree_hook print_xnode;
324 
325   /* Called to print language-dependent parts of a class 'd', class
326      't', and IDENTIFIER_NODE nodes.  */
327   lang_print_tree_hook print_decl;
328   lang_print_tree_hook print_type;
329   lang_print_tree_hook print_identifier;
330 
331   /* Computes the name to use to print a declaration.  DECL is the
332      non-NULL declaration in question.  VERBOSITY determines what
333      information will be printed: 0: DECL_NAME, demangled as
334      necessary.  1: and scope information.  2: and any other
335      information that might be interesting, such as function parameter
336      types in C++.  */
337   const char *(*decl_printable_name) PARAMS ((tree decl, int verbosity));
338 
339   /* Called by report_error_function to print out function name.  */
340   void (*print_error_function) PARAMS ((struct diagnostic_context *,
341 					const char *));
342 
343   /* Called from expr_size to calculate the size of the value of an
344      expression in a language-dependent way.  Returns a tree for the size
345      in bytes.  A frontend can call lhd_expr_size to get the default
346      semantics in cases that it doesn't want to handle specially.  */
347   tree (*expr_size) PARAMS ((tree));
348 
349   /* Pointers to machine-independent attribute tables, for front ends
350      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
351      table of attributes specific to the language, a table of
352      attributes common to two or more languages (to allow easy
353      sharing), and a table of attributes for checking formats.  */
354   const struct attribute_spec *attribute_table;
355   const struct attribute_spec *common_attribute_table;
356   const struct attribute_spec *format_attribute_table;
357 
358   /* Function-related language hooks.  */
359   struct lang_hooks_for_functions function;
360 
361   struct lang_hooks_for_tree_inlining tree_inlining;
362 
363   struct lang_hooks_for_tree_dump tree_dump;
364 
365   struct lang_hooks_for_decls decls;
366 
367   struct lang_hooks_for_types types;
368 
369   /* Whenever you add entries here, make sure you adjust langhooks-def.h
370      and langhooks.c accordingly.  */
371 };
372 
373 /* Each front end provides its own.  */
374 extern const struct lang_hooks lang_hooks;
375 
376 #endif /* GCC_LANG_HOOKS_H */
377