1 | /* Some code common to C and ObjC front ends. |
2 | Copyright (C) 2001-2024 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 it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "c-tree.h" |
24 | #include "intl.h" |
25 | #include "c-family/c-pretty-print.h" |
26 | #include "tree-pretty-print.h" |
27 | #include "gimple-pretty-print.h" |
28 | #include "langhooks.h" |
29 | #include "c-objc-common.h" |
30 | #include "gcc-rich-location.h" |
31 | #include "stringpool.h" |
32 | #include "attribs.h" |
33 | #include "dwarf2.h" |
34 | |
35 | static bool c_tree_printer (pretty_printer *, text_info *, const char *, |
36 | int, bool, bool, bool, bool *, const char **); |
37 | |
38 | /* Info for C language features which can be queried through |
39 | __has_{feature,extension}. */ |
40 | |
41 | struct c_feature_info |
42 | { |
43 | const char *ident; |
44 | const int *enable_flag; |
45 | }; |
46 | |
47 | static const c_feature_info c_feature_table[] = |
48 | { |
49 | { .ident: "c_alignas" , .enable_flag: &flag_isoc11 }, |
50 | { .ident: "c_alignof" , .enable_flag: &flag_isoc11 }, |
51 | { .ident: "c_atomic" , .enable_flag: &flag_isoc11 }, |
52 | { .ident: "c_generic_selections" , .enable_flag: &flag_isoc11 }, |
53 | { .ident: "c_static_assert" , .enable_flag: &flag_isoc11 }, |
54 | { .ident: "c_thread_local" , .enable_flag: &flag_isoc11 }, |
55 | { .ident: "cxx_binary_literals" , .enable_flag: &flag_isoc23 } |
56 | }; |
57 | |
58 | /* Register features specific to the C language. */ |
59 | |
60 | void |
61 | c_register_features () |
62 | { |
63 | for (unsigned i = 0; i < ARRAY_SIZE (c_feature_table); i++) |
64 | { |
65 | const c_feature_info *info = c_feature_table + i; |
66 | const bool feat_p = !info->enable_flag || *info->enable_flag; |
67 | c_common_register_feature (info->ident, feat_p); |
68 | } |
69 | } |
70 | |
71 | bool |
72 | c_missing_noreturn_ok_p (tree decl) |
73 | { |
74 | /* A missing noreturn is ok for the `main' function. */ |
75 | if (!MAIN_NAME_P (DECL_ASSEMBLER_NAME (decl))) |
76 | return false; |
77 | |
78 | return flag_hosted |
79 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl))) == integer_type_node; |
80 | } |
81 | |
82 | /* Called from check_global_declaration. */ |
83 | |
84 | bool |
85 | c_warn_unused_global_decl (const_tree decl) |
86 | { |
87 | if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl)) |
88 | return false; |
89 | if (DECL_IN_SYSTEM_HEADER (decl)) |
90 | return false; |
91 | |
92 | return true; |
93 | } |
94 | |
95 | /* Initialization common to C and Objective-C front ends. */ |
96 | bool |
97 | c_objc_common_init (void) |
98 | { |
99 | c_init_decl_processing (); |
100 | |
101 | return c_common_init (); |
102 | } |
103 | |
104 | /* Decide whether it's worth saying that TYPE is also known as some other |
105 | type. Return the other type if so, otherwise return TYPE. */ |
106 | |
107 | static tree |
108 | get_aka_type (tree type) |
109 | { |
110 | if (type == error_mark_node) |
111 | return type; |
112 | |
113 | tree result; |
114 | if (typedef_variant_p (type)) |
115 | { |
116 | /* Saying that "foo" is also known as "struct foo" or |
117 | "struct <anonymous>" is unlikely to be useful, since users of |
118 | structure-like types would already know that they're structures. |
119 | The same applies to unions and enums; in general, printing the |
120 | tag is only useful if it has a different name. */ |
121 | tree orig_type = DECL_ORIGINAL_TYPE (TYPE_NAME (type)); |
122 | tree_code code = TREE_CODE (orig_type); |
123 | tree orig_id = TYPE_IDENTIFIER (orig_type); |
124 | if ((code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE) |
125 | && (!orig_id || TYPE_IDENTIFIER (type) == orig_id)) |
126 | return type; |
127 | |
128 | if (!user_facing_original_type_p (type)) |
129 | return type; |
130 | |
131 | result = get_aka_type (type: orig_type); |
132 | } |
133 | else |
134 | { |
135 | tree canonical = TYPE_CANONICAL (type); |
136 | if (canonical && TREE_CODE (type) != TREE_CODE (canonical)) |
137 | return canonical; |
138 | |
139 | /* Recursive calls might choose a middle ground between TYPE |
140 | (which has no typedefs stripped) and CANONICAL (which has |
141 | all typedefs stripped). So try to reuse TYPE or CANONICAL if |
142 | convenient, but be prepared to create a new type if necessary. */ |
143 | switch (TREE_CODE (type)) |
144 | { |
145 | case POINTER_TYPE: |
146 | case REFERENCE_TYPE: |
147 | { |
148 | tree target_type = get_aka_type (TREE_TYPE (type)); |
149 | |
150 | if (target_type == TREE_TYPE (type)) |
151 | return type; |
152 | |
153 | if (canonical && target_type == TREE_TYPE (canonical)) |
154 | return canonical; |
155 | |
156 | result = (TREE_CODE (type) == POINTER_TYPE |
157 | ? build_pointer_type (target_type) |
158 | : build_reference_type (target_type)); |
159 | break; |
160 | } |
161 | |
162 | case ARRAY_TYPE: |
163 | { |
164 | tree element_type = get_aka_type (TREE_TYPE (type)); |
165 | tree index_type = (TYPE_DOMAIN (type) |
166 | ? get_aka_type (TYPE_DOMAIN (type)) |
167 | : NULL_TREE); |
168 | |
169 | if (element_type == TREE_TYPE (type) |
170 | && index_type == TYPE_DOMAIN (type)) |
171 | return type; |
172 | |
173 | if (canonical |
174 | && element_type == TREE_TYPE (canonical) |
175 | && index_type == TYPE_DOMAIN (canonical)) |
176 | return canonical; |
177 | |
178 | result = build_array_type (element_type, index_type, |
179 | TYPE_TYPELESS_STORAGE (type)); |
180 | break; |
181 | } |
182 | |
183 | case FUNCTION_TYPE: |
184 | { |
185 | tree return_type = get_aka_type (TREE_TYPE (type)); |
186 | |
187 | tree args = TYPE_ARG_TYPES (type); |
188 | if (args == error_mark_node) |
189 | return type; |
190 | |
191 | auto_vec<tree, 32> arg_types; |
192 | bool type_ok_p = true; |
193 | while (args && args != void_list_node) |
194 | { |
195 | tree arg_type = get_aka_type (TREE_VALUE (args)); |
196 | arg_types.safe_push (obj: arg_type); |
197 | type_ok_p &= (arg_type == TREE_VALUE (args)); |
198 | args = TREE_CHAIN (args); |
199 | } |
200 | |
201 | if (type_ok_p && return_type == TREE_TYPE (type)) |
202 | return type; |
203 | |
204 | unsigned int i; |
205 | tree arg_type; |
206 | FOR_EACH_VEC_ELT_REVERSE (arg_types, i, arg_type) |
207 | args = tree_cons (NULL_TREE, arg_type, args); |
208 | result = build_function_type (return_type, args); |
209 | break; |
210 | } |
211 | |
212 | default: |
213 | return canonical ? canonical : type; |
214 | } |
215 | } |
216 | return build_type_attribute_qual_variant (result, TYPE_ATTRIBUTES (type), |
217 | TYPE_QUALS (type)); |
218 | } |
219 | |
220 | /* Print T to CPP. */ |
221 | |
222 | static void |
223 | print_type (c_pretty_printer *cpp, tree t, bool *quoted) |
224 | { |
225 | if (t == error_mark_node) |
226 | { |
227 | pp_string (cpp, _("{erroneous}" )); |
228 | return; |
229 | } |
230 | |
231 | gcc_assert (TYPE_P (t)); |
232 | struct obstack *ob = pp_buffer (cpp)->obstack; |
233 | char *p = (char *) obstack_base (ob); |
234 | /* Remember the end of the initial dump. */ |
235 | int len = obstack_object_size (ob); |
236 | |
237 | tree name = TYPE_NAME (t); |
238 | if (name && TREE_CODE (name) == TYPE_DECL && DECL_NAME (name)) |
239 | pp_identifier (cpp, lang_hooks.decl_printable_name (name, 2)); |
240 | else |
241 | cpp->type_id (t); |
242 | |
243 | /* If we're printing a type that involves typedefs, also print the |
244 | stripped version. But sometimes the stripped version looks |
245 | exactly the same, so we don't want it after all. To avoid |
246 | printing it in that case, we play ugly obstack games. */ |
247 | tree aka_type = get_aka_type (type: t); |
248 | if (aka_type != t) |
249 | { |
250 | c_pretty_printer cpp2; |
251 | /* Print the stripped version into a temporary printer. */ |
252 | cpp2.type_id (aka_type); |
253 | struct obstack *ob2 = cpp2.buffer->obstack; |
254 | /* Get the stripped version from the temporary printer. */ |
255 | const char *aka = (char *) obstack_base (ob2); |
256 | int aka_len = obstack_object_size (ob2); |
257 | int type1_len = obstack_object_size (ob) - len; |
258 | |
259 | /* If they are identical, bail out. */ |
260 | if (aka_len == type1_len && memcmp (s1: p + len, s2: aka, n: aka_len) == 0) |
261 | return; |
262 | |
263 | /* They're not, print the stripped version now. */ |
264 | if (*quoted) |
265 | pp_end_quote (cpp, pp_show_color (cpp)); |
266 | pp_c_whitespace (cpp); |
267 | pp_left_brace (cpp); |
268 | pp_c_ws_string (cpp, _("aka" )); |
269 | pp_c_whitespace (cpp); |
270 | if (*quoted) |
271 | pp_begin_quote (cpp, pp_show_color (cpp)); |
272 | cpp->type_id (aka_type); |
273 | if (*quoted) |
274 | pp_end_quote (cpp, pp_show_color (cpp)); |
275 | pp_right_brace (cpp); |
276 | /* No further closing quotes are needed. */ |
277 | *quoted = false; |
278 | } |
279 | } |
280 | |
281 | /* Called during diagnostic message formatting process to print a |
282 | source-level entity onto BUFFER. The meaning of the format specifiers |
283 | is as follows: |
284 | %D: a general decl, |
285 | %E: an identifier or expression, |
286 | %F: a function declaration, |
287 | %T: a type. |
288 | %V: a list of type qualifiers from a tree. |
289 | %v: an explicit list of type qualifiers |
290 | %#v: an explicit list of type qualifiers of a function type. |
291 | |
292 | Please notice when called, the `%' part was already skipped by the |
293 | diagnostic machinery. */ |
294 | static bool |
295 | c_tree_printer (pretty_printer *pp, text_info *text, const char *spec, |
296 | int precision, bool wide, bool set_locus, bool hash, |
297 | bool *quoted, const char **) |
298 | { |
299 | tree t = NULL_TREE; |
300 | // FIXME: the next cast should be a dynamic_cast, when it is permitted. |
301 | c_pretty_printer *cpp = (c_pretty_printer *) pp; |
302 | pp->padding = pp_none; |
303 | |
304 | if (precision != 0 || wide) |
305 | return false; |
306 | |
307 | if (*spec != 'v') |
308 | { |
309 | t = va_arg (*text->m_args_ptr, tree); |
310 | if (set_locus) |
311 | text->set_location (idx: 0, DECL_SOURCE_LOCATION (t), |
312 | range_display_kind: SHOW_RANGE_WITH_CARET); |
313 | } |
314 | |
315 | switch (*spec) |
316 | { |
317 | case 'D': |
318 | if (VAR_P (t) && DECL_HAS_DEBUG_EXPR_P (t)) |
319 | { |
320 | t = DECL_DEBUG_EXPR (t); |
321 | if (!DECL_P (t)) |
322 | { |
323 | cpp->expression (t); |
324 | return true; |
325 | } |
326 | } |
327 | /* FALLTHRU */ |
328 | |
329 | case 'F': |
330 | if (DECL_NAME (t)) |
331 | { |
332 | pp_identifier (cpp, lang_hooks.decl_printable_name (t, 2)); |
333 | return true; |
334 | } |
335 | break; |
336 | |
337 | case 'T': |
338 | print_type (cpp, t, quoted); |
339 | return true; |
340 | |
341 | case 'E': |
342 | if (TREE_CODE (t) == IDENTIFIER_NODE) |
343 | pp_identifier (cpp, IDENTIFIER_POINTER (t)); |
344 | else |
345 | cpp->expression (t); |
346 | return true; |
347 | |
348 | case 'V': |
349 | pp_c_type_qualifier_list (cpp, t); |
350 | return true; |
351 | |
352 | case 'v': |
353 | pp_c_cv_qualifiers (pp: cpp, va_arg (*text->m_args_ptr, int), func_type: hash); |
354 | return true; |
355 | |
356 | default: |
357 | return false; |
358 | } |
359 | |
360 | pp_string (cpp, _("({anonymous})" )); |
361 | return true; |
362 | } |
363 | |
364 | /* C-specific implementation of range_label::get_text () vfunc for |
365 | range_label_for_type_mismatch. */ |
366 | |
367 | label_text |
368 | range_label_for_type_mismatch::get_text (unsigned /*range_idx*/) const |
369 | { |
370 | if (m_labelled_type == NULL_TREE) |
371 | return label_text::borrow (NULL); |
372 | |
373 | c_pretty_printer cpp; |
374 | bool quoted = false; |
375 | print_type (cpp: &cpp, t: m_labelled_type, quoted: "ed); |
376 | return label_text::take (buffer: xstrdup (pp_formatted_text (&cpp))); |
377 | } |
378 | |
379 | |
380 | /* In C and ObjC, all decls have "C" linkage. */ |
381 | bool |
382 | has_c_linkage (const_tree decl ATTRIBUTE_UNUSED) |
383 | { |
384 | return true; |
385 | } |
386 | |
387 | void |
388 | c_initialize_diagnostics (diagnostic_context *context) |
389 | { |
390 | pretty_printer *base = context->printer; |
391 | c_pretty_printer *pp = XNEW (c_pretty_printer); |
392 | context->printer = new (pp) c_pretty_printer (); |
393 | |
394 | /* It is safe to free this object because it was previously XNEW()'d. */ |
395 | base->~pretty_printer (); |
396 | XDELETE (base); |
397 | |
398 | c_common_diagnostics_set_defaults (context); |
399 | diagnostic_format_decoder (context) = &c_tree_printer; |
400 | } |
401 | |
402 | int |
403 | c_types_compatible_p (tree x, tree y) |
404 | { |
405 | return comptypes (TYPE_MAIN_VARIANT (x), TYPE_MAIN_VARIANT (y)); |
406 | } |
407 | |
408 | /* Determine if the type is a variably modified type for the backend. */ |
409 | |
410 | bool |
411 | c_var_mod_p (tree x, tree fn ATTRIBUTE_UNUSED) |
412 | { |
413 | return C_TYPE_VARIABLY_MODIFIED (x); |
414 | } |
415 | |
416 | /* Special routine to get the alias set of T for C. */ |
417 | |
418 | alias_set_type |
419 | c_get_alias_set (tree t) |
420 | { |
421 | /* Allow aliasing between enumeral types and the underlying |
422 | integer type. This is required since those are compatible types. */ |
423 | if (TREE_CODE (t) == ENUMERAL_TYPE) |
424 | return get_alias_set (ENUM_UNDERLYING_TYPE (t)); |
425 | |
426 | /* Structs with variable size can alias different incompatible |
427 | structs. Let them alias anything. */ |
428 | if (RECORD_OR_UNION_TYPE_P (t) && C_TYPE_VARIABLE_SIZE (t)) |
429 | return 0; |
430 | |
431 | return c_common_get_alias_set (t); |
432 | } |
433 | |
434 | /* In C there are no invisible parameters like in C++ (this, in-charge, VTT, |
435 | etc.). */ |
436 | |
437 | int |
438 | maybe_adjust_arg_pos_for_attribute (const_tree) |
439 | { |
440 | return 0; |
441 | } |
442 | |
443 | /* In C, no expression is dependent. */ |
444 | |
445 | bool |
446 | instantiation_dependent_expression_p (tree) |
447 | { |
448 | return false; |
449 | } |
450 | |
451 | /* Return -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute |
452 | value otherwise. */ |
453 | int |
454 | c_type_dwarf_attribute (const_tree type, int attr) |
455 | { |
456 | if (type == NULL_TREE) |
457 | return -1; |
458 | |
459 | switch (attr) |
460 | { |
461 | case DW_AT_export_symbols: |
462 | if (RECORD_OR_UNION_TYPE_P (type) && TYPE_NAME (type) == NULL_TREE) |
463 | return 1; |
464 | break; |
465 | |
466 | default: |
467 | break; |
468 | } |
469 | |
470 | return -1; |
471 | } |
472 | |