1 /* Generate information regarding function declarations and definitions based
2 on information stored in GCC's tree structure. This code implements the
4 Copyright (C) 1989-2020 Free Software Foundation, Inc.
5 Contributed by Ron Guilmette (rfg@segfault.us.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
36 static const char *data_type
;
38 static char *affix_data_type (const char *) ATTRIBUTE_MALLOC
;
39 static const char *gen_formal_list_for_type (tree
, formals_style
);
40 static const char *gen_formal_list_for_func_def (tree
, formals_style
);
41 static const char *gen_type (const char *, tree
, formals_style
);
42 static const char *gen_decl (tree
, int, formals_style
);
44 /* Given a string representing an entire type or an entire declaration
45 which only lacks the actual "data-type" specifier (at its left end),
46 affix the data-type specifier to the left end of the given type
47 specification or object declaration.
49 Because of C language weirdness, the data-type specifier (which normally
50 goes in at the very left end) may have to be slipped in just to the
51 right of any leading "const" or "volatile" qualifiers (there may be more
52 than one). Actually this may not be strictly necessary because it seems
53 that GCC (at least) accepts `<data-type> const foo;' and treats it the
54 same as `const <data-type> foo;' but people are accustomed to seeing
55 `const char *foo;' and *not* `char const *foo;' so we try to create types
56 that look as expected. */
59 affix_data_type (const char *param
)
61 char *const type_or_decl
= ASTRDUP (param
);
62 char *p
= type_or_decl
;
63 char *qualifiers_then_data_type
;
66 /* Skip as many leading const's or volatile's as there are. */
70 if (!strncmp (p
, "volatile ", 9))
75 if (!strncmp (p
, "const ", 6))
83 /* p now points to the place where we can insert the data type. We have to
84 add a blank after the data-type of course. */
86 if (p
== type_or_decl
)
87 return concat (data_type
, " ", type_or_decl
, NULL
);
91 qualifiers_then_data_type
= concat (type_or_decl
, data_type
, NULL
);
93 return reconcat (qualifiers_then_data_type
,
94 qualifiers_then_data_type
, " ", p
, NULL
);
97 /* Given a tree node which represents some "function type", generate the
98 source code version of a formal parameter list (of some given style) for
99 this function type. Return the whole formal parameter list (including
100 a pair of surrounding parens) as a string. Note that if the style
101 we are currently aiming for is non-ansi, then we just return a pair
102 of empty parens here. */
105 gen_formal_list_for_type (tree fntype
, formals_style style
)
107 const char *formal_list
= "";
113 formal_type
= TYPE_ARG_TYPES (fntype
);
114 while (formal_type
&& TREE_VALUE (formal_type
) != void_type_node
)
116 const char *this_type
;
119 formal_list
= concat (formal_list
, ", ", NULL
);
121 this_type
= gen_type ("", TREE_VALUE (formal_type
), ansi
);
123 = ((strlen (this_type
))
124 ? concat (formal_list
, affix_data_type (this_type
), NULL
)
125 : concat (formal_list
, data_type
, NULL
));
127 formal_type
= TREE_CHAIN (formal_type
);
130 /* If we got to here, then we are trying to generate an ANSI style formal
133 New style prototyped ANSI formal parameter lists should in theory always
134 contain some stuff between the opening and closing parens, even if it is
137 The brutal truth though is that there is lots of old K&R code out there
138 which contains declarations of "pointer-to-function" parameters and
139 these almost never have fully specified formal parameter lists associated
140 with them. That is, the pointer-to-function parameters are declared
141 with just empty parameter lists.
143 In cases such as these, protoize should really insert *something* into
144 the vacant parameter lists, but what? It has no basis on which to insert
145 anything in particular.
147 Here, we make life easy for protoize by trying to distinguish between
148 K&R empty parameter lists and new-style prototyped parameter lists
149 that actually contain "void". In the latter case we (obviously) want
150 to output the "void" verbatim, and that what we do. In the former case,
151 we do our best to give protoize something nice to insert.
153 This "something nice" should be something that is still valid (when
154 re-compiled) but something that can clearly indicate to the user that
155 more typing information (for the parameter list) should be added (by
156 hand) at some convenient moment.
158 The string chosen here is a comment with question marks in it. */
162 if (prototype_p (fntype
))
163 /* assert (TREE_VALUE (TYPE_ARG_TYPES (fntype)) == void_type_node); */
164 formal_list
= "void";
166 formal_list
= "/* ??? */";
170 /* If there were at least some parameters, and if the formals-types-list
171 petered out to a NULL (i.e. without being terminated by a
172 void_type_node) then we need to tack on an ellipsis. */
174 formal_list
= concat (formal_list
, ", ...", NULL
);
177 return concat (" (", formal_list
, ")", NULL
);
180 /* Generate a parameter list for a function definition (in some given style).
182 Note that this routine has to be separate (and different) from the code that
183 generates the prototype parameter lists for function declarations, because
184 in the case of a function declaration, all we have to go on is a tree node
185 representing the function's own "function type". This can tell us the types
186 of all of the formal parameters for the function, but it cannot tell us the
187 actual *names* of each of the formal parameters. We need to output those
188 parameter names for each function definition.
190 This routine gets a pointer to a tree node which represents the actual
191 declaration of the given function, and this DECL node has a list of formal
192 parameter (variable) declarations attached to it. These formal parameter
193 (variable) declaration nodes give us the actual names of the formal
194 parameters for the given function definition.
196 This routine returns a string which is the source form for the entire
197 function formal parameter list. */
200 gen_formal_list_for_func_def (tree fndecl
, formals_style style
)
202 const char *formal_list
= "";
205 formal_decl
= DECL_ARGUMENTS (fndecl
);
208 const char *this_formal
;
210 if (*formal_list
&& ((style
== ansi
) || (style
== k_and_r_names
)))
211 formal_list
= concat (formal_list
, ", ", NULL
);
212 this_formal
= gen_decl (formal_decl
, 0, style
);
213 if (style
== k_and_r_decls
)
214 formal_list
= concat (formal_list
, this_formal
, "; ", NULL
);
216 formal_list
= concat (formal_list
, this_formal
, NULL
);
217 formal_decl
= TREE_CHAIN (formal_decl
);
221 if (!DECL_ARGUMENTS (fndecl
))
222 formal_list
= concat (formal_list
, "void", NULL
);
223 if (stdarg_p (TREE_TYPE (fndecl
)))
224 formal_list
= concat (formal_list
, ", ...", NULL
);
226 if ((style
== ansi
) || (style
== k_and_r_names
))
227 formal_list
= concat (" (", formal_list
, ")", NULL
);
231 /* Generate a string which is the source code form for a given type (t). This
232 routine is ugly and complex because the C syntax for declarations is ugly
233 and complex. This routine is straightforward so long as *no* pointer types,
234 array types, or function types are involved.
236 In the simple cases, this routine will return the (string) value which was
237 passed in as the "ret_val" argument. Usually, this starts out either as an
238 empty string, or as the name of the declared item (i.e. the formal function
241 This routine will also return with the global variable "data_type" set to
242 some string value which is the "basic" data-type of the given complete type.
243 This "data_type" string can be concatenated onto the front of the returned
244 string after this routine returns to its caller.
246 In complicated cases involving pointer types, array types, or function
247 types, the C declaration syntax requires an "inside out" approach, i.e. if
248 you have a type which is a "pointer-to-function" type, you need to handle
249 the "pointer" part first, but it also has to be "innermost" (relative to
250 the declaration stuff for the "function" type). Thus, is this case, you
251 must prepend a "(*" and append a ")" to the name of the item (i.e. formal
252 variable). Then you must append and prepend the other info for the
253 "function type" part of the overall type.
255 To handle the "innermost precedence" rules of complicated C declarators, we
256 do the following (in this routine). The input parameter called "ret_val"
257 is treated as a "seed". Each time gen_type is called (perhaps recursively)
258 some additional strings may be appended or prepended (or both) to the "seed"
259 string. If yet another (lower) level of the GCC tree exists for the given
260 type (as in the case of a pointer type, an array type, or a function type)
261 then the (wrapped) seed is passed to a (recursive) invocation of gen_type()
262 this recursive invocation may again "wrap" the (new) seed with yet more
263 declarator stuff, by appending, prepending (or both). By the time the
264 recursion bottoms out, the "seed value" at that point will have a value
265 which is (almost) the complete source version of the declarator (except
266 for the data_type info). Thus, this deepest "seed" value is simply passed
267 back up through all of the recursive calls until it is given (as the return
268 value) to the initial caller of the gen_type() routine. All that remains
269 to do at this point is for the initial caller to prepend the "data_type"
270 string onto the returned "seed". */
273 gen_type (const char *ret_val
, tree t
, formals_style style
)
277 /* If there is a typedef name for this type, use it. */
278 if (TYPE_NAME (t
) && TREE_CODE (TYPE_NAME (t
)) == TYPE_DECL
)
279 data_type
= IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t
)));
282 switch (TREE_CODE (t
))
286 ret_val
= concat ("_Atomic ", ret_val
, NULL
);
287 if (TYPE_READONLY (t
))
288 ret_val
= concat ("const ", ret_val
, NULL
);
289 if (TYPE_VOLATILE (t
))
290 ret_val
= concat ("volatile ", ret_val
, NULL
);
292 ret_val
= concat ("*", ret_val
, NULL
);
294 if (TREE_CODE (TREE_TYPE (t
)) == ARRAY_TYPE
|| TREE_CODE (TREE_TYPE (t
)) == FUNCTION_TYPE
)
295 ret_val
= concat ("(", ret_val
, ")", NULL
);
297 ret_val
= gen_type (ret_val
, TREE_TYPE (t
), style
);
302 if (!COMPLETE_TYPE_P (t
) || TREE_CODE (TYPE_SIZE (t
)) != INTEGER_CST
)
303 ret_val
= gen_type (concat (ret_val
, "[]", NULL
),
304 TREE_TYPE (t
), style
);
305 else if (int_size_in_bytes (t
) == 0)
306 ret_val
= gen_type (concat (ret_val
, "[0]", NULL
),
307 TREE_TYPE (t
), style
);
311 sprintf (buff
, "[" HOST_WIDE_INT_PRINT_DEC
"]",
312 int_size_in_bytes (t
)
313 / int_size_in_bytes (TREE_TYPE (t
)));
314 ret_val
= gen_type (concat (ret_val
, buff
, NULL
),
315 TREE_TYPE (t
), style
);
320 ret_val
= gen_type (concat (ret_val
,
321 gen_formal_list_for_type (t
, style
),
323 TREE_TYPE (t
), style
);
326 case IDENTIFIER_NODE
:
327 data_type
= IDENTIFIER_POINTER (t
);
330 /* The following three cases are complicated by the fact that a
331 user may do something really stupid, like creating a brand new
332 "anonymous" type specification in a formal argument list (or as
333 part of a function return type specification). For example:
335 int f (enum { red, green, blue } color);
337 In such cases, we have no name that we can put into the prototype
338 to represent the (anonymous) type. Thus, we have to generate the
339 whole darn type specification. Yuck! */
343 data_type
= IDENTIFIER_POINTER (TYPE_NAME (t
));
347 chain_p
= TYPE_FIELDS (t
);
350 data_type
= concat (data_type
, gen_decl (chain_p
, 0, ansi
),
352 chain_p
= TREE_CHAIN (chain_p
);
353 data_type
= concat (data_type
, "; ", NULL
);
355 data_type
= concat ("{ ", data_type
, "}", NULL
);
357 data_type
= concat ("struct ", data_type
, NULL
);
362 data_type
= IDENTIFIER_POINTER (TYPE_NAME (t
));
366 chain_p
= TYPE_FIELDS (t
);
369 data_type
= concat (data_type
, gen_decl (chain_p
, 0, ansi
),
371 chain_p
= TREE_CHAIN (chain_p
);
372 data_type
= concat (data_type
, "; ", NULL
);
374 data_type
= concat ("{ ", data_type
, "}", NULL
);
376 data_type
= concat ("union ", data_type
, NULL
);
381 data_type
= IDENTIFIER_POINTER (TYPE_NAME (t
));
385 chain_p
= TYPE_VALUES (t
);
388 data_type
= concat (data_type
,
389 IDENTIFIER_POINTER (TREE_PURPOSE (chain_p
)), NULL
);
390 chain_p
= TREE_CHAIN (chain_p
);
392 data_type
= concat (data_type
, ", ", NULL
);
394 data_type
= concat ("{ ", data_type
, " }", NULL
);
396 data_type
= concat ("enum ", data_type
, NULL
);
400 data_type
= IDENTIFIER_POINTER (DECL_NAME (t
));
404 case FIXED_POINT_TYPE
:
405 data_type
= IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t
)));
406 /* Normally, `unsigned' is part of the deal. Not so if it comes
407 with a type qualifier. */
408 if (TYPE_UNSIGNED (t
) && TYPE_QUALS (t
))
409 data_type
= concat ("unsigned ", data_type
, NULL
);
414 data_type
= IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (t
)));
422 data_type
= "[ERROR]";
430 ret_val
= concat ("_Atomic ", ret_val
, NULL
);
431 if (TYPE_READONLY (t
))
432 ret_val
= concat ("const ", ret_val
, NULL
);
433 if (TYPE_VOLATILE (t
))
434 ret_val
= concat ("volatile ", ret_val
, NULL
);
435 if (TYPE_RESTRICT (t
))
436 ret_val
= concat ("restrict ", ret_val
, NULL
);
440 /* Generate a string (source) representation of an entire entity declaration
441 (using some particular style for function types).
443 The given entity may be either a variable or a function.
445 If the "is_func_definition" parameter is nonzero, assume that the thing
446 we are generating a declaration for is a FUNCTION_DECL node which is
447 associated with a function definition. In this case, we can assume that
448 an attached list of DECL nodes for function formal arguments is present. */
451 gen_decl (tree decl
, int is_func_definition
, formals_style style
)
455 if (DECL_NAME (decl
))
456 ret_val
= IDENTIFIER_POINTER (DECL_NAME (decl
));
460 /* If we are just generating a list of names of formal parameters, we can
461 simply return the formal parameter name (with no typing information
462 attached to it) now. */
464 if (style
== k_and_r_names
)
467 /* Note that for the declaration of some entity (either a function or a
468 data object, like for instance a parameter) if the entity itself was
469 declared as either const or volatile, then const and volatile properties
470 are associated with just the declaration of the entity, and *not* with
471 the `type' of the entity. Thus, for such declared entities, we have to
472 generate the qualifiers here. */
474 if (TREE_THIS_VOLATILE (decl
))
475 ret_val
= concat ("volatile ", ret_val
, NULL
);
476 if (TREE_READONLY (decl
))
477 ret_val
= concat ("const ", ret_val
, NULL
);
481 /* For FUNCTION_DECL nodes, there are two possible cases here. First, if
482 this FUNCTION_DECL node was generated from a function "definition", then
483 we will have a list of DECL_NODE's, one for each of the function's formal
484 parameters. In this case, we can print out not only the types of each
485 formal, but also each formal's name. In the second case, this
486 FUNCTION_DECL node came from an actual function declaration (and *not*
487 a definition). In this case, we do nothing here because the formal
488 argument type-list will be output later, when the "type" of the function
489 is added to the string we are building. Note that the ANSI-style formal
490 parameter list is considered to be a (suffix) part of the "type" of the
493 if (TREE_CODE (decl
) == FUNCTION_DECL
&& is_func_definition
)
495 ret_val
= concat (ret_val
, gen_formal_list_for_func_def (decl
, ansi
),
498 /* Since we have already added in the formals list stuff, here we don't
499 add the whole "type" of the function we are considering (which
500 would include its parameter-list info), rather, we only add in
501 the "type" of the "type" of the function, which is really just
502 the return-type of the function (and does not include the parameter
505 ret_val
= gen_type (ret_val
, TREE_TYPE (TREE_TYPE (decl
)), style
);
508 ret_val
= gen_type (ret_val
, TREE_TYPE (decl
), style
);
510 ret_val
= affix_data_type (ret_val
);
512 if (TREE_CODE (decl
) != FUNCTION_DECL
&& C_DECL_REGISTER (decl
))
513 ret_val
= concat ("register ", ret_val
, NULL
);
514 if (TREE_PUBLIC (decl
))
515 ret_val
= concat ("extern ", ret_val
, NULL
);
516 if (TREE_CODE (decl
) == FUNCTION_DECL
&& !TREE_PUBLIC (decl
))
517 ret_val
= concat ("static ", ret_val
, NULL
);
522 extern FILE *aux_info_file
;
524 /* Generate and write a new line of info to the aux-info (.X) file. This
525 routine is called once for each function declaration, and once for each
526 function definition (even the implicit ones). */
529 gen_aux_info_record (tree fndecl
, int is_definition
, int is_implicit
,
532 if (flag_gen_aux_info
)
534 static int compiled_from_record
= 0;
535 expanded_location xloc
= expand_location (DECL_SOURCE_LOCATION (fndecl
));
537 /* Each output .X file must have a header line. Write one now if we
538 have not yet done so. */
540 if (!compiled_from_record
++)
542 /* The first line tells which directory file names are relative to.
543 Currently, -aux-info works only for files in the working
544 directory, so just use a `.' as a placeholder for now. */
545 fprintf (aux_info_file
, "/* compiled from: . */\n");
548 /* Write the actual line of auxiliary info. */
550 fprintf (aux_info_file
, "/* %s:%d:%c%c */ %s;",
551 xloc
.file
, xloc
.line
,
552 (is_implicit
) ? 'I' : (is_prototyped
) ? 'N' : 'O',
553 (is_definition
) ? 'F' : 'C',
554 gen_decl (fndecl
, is_definition
, ansi
));
556 /* If this is an explicit function declaration, we need to also write
557 out an old-style (i.e. K&R) function header, just in case the user
558 wants to run unprotoize. */
562 fprintf (aux_info_file
, " /*%s %s*/",
563 gen_formal_list_for_func_def (fndecl
, k_and_r_names
),
564 gen_formal_list_for_func_def (fndecl
, k_and_r_decls
));
567 fprintf (aux_info_file
, "\n");