1	/* CPP Library. (Directive handling.)
2	Copyright (C) 1986-2023 Free Software Foundation, Inc.
3	Contributed by Per Bothner, 1994-95.
4	Based on CCCP program by Paul Rubin, June 1986
5	Adapted to ANSI C, Richard Stallman, Jan 1987
6
7	This program is free software; you can redistribute it and/or modify it
8	under the terms of the GNU General Public License as published by the
9	Free Software Foundation; either version 3, or (at your option) any
10	later version.
11
12	This program is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.
16
17	You should have received a copy of the GNU General Public License
18	along with this program; see the file COPYING3. If not see
19	<http://www.gnu.org/licenses/>. */
20
21	#include "config.h"
22	#include "system.h"
23	#include "cpplib.h"
24	#include "internal.h"
25	#include "mkdeps.h"
26	#include "obstack.h"
27
28	/* Stack of conditionals currently in progress
29	(including both successful and failing conditionals). */
30	struct if_stack
31	{
32	struct if_stack *next;
33	location_t line; /* Line where condition started. */
34	const cpp_hashnode *mi_cmacro;/* macro name for #ifndef around entire file */
35	bool skip_elses; /* Can future #else / #elif be skipped? */
36	bool was_skipping; /* If were skipping on entry. */
37	int type; /* Most recent conditional for diagnostics. */
38	};
39
40	/* Contains a registered pragma or pragma namespace. */
41	typedef void (*pragma_cb) (cpp_reader *);
42	struct pragma_entry
43	{
44	struct pragma_entry *next;
45	const cpp_hashnode *pragma; /* Name and length. */
46	bool is_nspace;
47	bool is_internal;
48	bool is_deferred;
49	bool allow_expansion;
50	union {
51	pragma_cb handler;
52	struct pragma_entry *space;
53	unsigned int ident;
54	} u;
55	};
56
57	/* Values for the origin field of struct directive. KANDR directives
58	come from traditional (K&R) C. STDC89 directives come from the
59	1989 C standard. STDC23 directives come from the C23 standard. EXTENSION
60	directives are extensions. */
61	#define KANDR 0
62	#define STDC89 1
63	#define STDC23 2
64	#define EXTENSION 3
65
66	/* Values for the flags field of struct directive. COND indicates a
67	conditional; IF_COND an opening conditional. INCL means to treat
68	"..." and <...> as q-char and h-char sequences respectively. IN_I
69	means this directive should be handled even if -fpreprocessed is in
70	effect (these are the directives with callback hooks).
71
72	EXPAND is set on directives that are always macro-expanded.
73
74	ELIFDEF is set on directives that are only handled for standards with the
75	#elifdef / #elifndef feature. */
76	#define COND (1 << 0)
77	#define IF_COND (1 << 1)
78	#define INCL (1 << 2)
79	#define IN_I (1 << 3)
80	#define EXPAND (1 << 4)
81	#define DEPRECATED (1 << 5)
82	#define ELIFDEF (1 << 6)
83
84	/* Defines one #-directive, including how to handle it. */
85	typedef void (*directive_handler) (cpp_reader *);
86	typedef struct directive directive;
87	struct directive
88	{
89	directive_handler handler; /* Function to handle directive. */
90	const uchar *name; /* Name of directive. */
91	unsigned short length; /* Length of name. */
92	unsigned char origin; /* Origin of directive. */
93	unsigned char flags; /* Flags describing this directive. */
94	};
95
96	/* Forward declarations. */
97
98	static void skip_rest_of_line (cpp_reader *);
99	static void check_eol (cpp_reader *, bool);
100	static void start_directive (cpp_reader *);
101	static void prepare_directive_trad (cpp_reader *);
102	static void end_directive (cpp_reader *, int);
103	static void directive_diagnostics (cpp_reader *, const directive *, int);
104	static void run_directive (cpp_reader *, int, const char *, size_t);
105	static char *glue_header_name (cpp_reader *);
106	static const char *parse_include (cpp_reader *, int *, const cpp_token ***,
107	location_t *);
108	static void push_conditional (cpp_reader *, int, int, const cpp_hashnode *);
109	static unsigned int read_flag (cpp_reader *, unsigned int);
110	static bool strtolinenum (const uchar *, size_t, linenum_type *, bool *);
111	static void do_diagnostic (cpp_reader *, enum cpp_diagnostic_level code,
112	enum cpp_warning_reason reason, int);
113	static cpp_hashnode *lex_macro_node (cpp_reader *, bool);
114	static int undefine_macros (cpp_reader *, cpp_hashnode *, void *);
115	static void do_include_common (cpp_reader *, enum include_type);
116	static struct pragma_entry *lookup_pragma_entry (struct pragma_entry *,
117	const cpp_hashnode *);
118	static int count_registered_pragmas (struct pragma_entry *);
119	static char ** save_registered_pragmas (struct pragma_entry *, char **);
120	static char ** restore_registered_pragmas (cpp_reader *, struct pragma_entry *,
121	char **);
122	static void do_pragma_once (cpp_reader *);
123	static void do_pragma_poison (cpp_reader *);
124	static void do_pragma_system_header (cpp_reader *);
125	static void do_pragma_dependency (cpp_reader *);
126	static void do_pragma_warning_or_error (cpp_reader *, bool error);
127	static void do_pragma_warning (cpp_reader *);
128	static void do_pragma_error (cpp_reader *);
129	static void do_linemarker (cpp_reader *);
130	static const cpp_token *get_token_no_padding (cpp_reader *);
131	static const cpp_token *get__Pragma_string (cpp_reader *);
132	static void destringize_and_run (cpp_reader *, const cpp_string *,
133	location_t);
134	static bool parse_answer (cpp_reader *, int, location_t, cpp_macro **);
135	static cpp_hashnode *parse_assertion (cpp_reader *, int, cpp_macro **);
136	static cpp_macro **find_answer (cpp_hashnode *, const cpp_macro *);
137	static void handle_assertion (cpp_reader *, const char *, int);
138	static void do_pragma_push_macro (cpp_reader *);
139	static void do_pragma_pop_macro (cpp_reader *);
140	static void cpp_pop_definition (cpp_reader *, struct def_pragma_macro *);
141
142	/* This is the table of directive handlers. All extensions other than
143	#warning, #include_next, and #import are deprecated. The name is
144	where the extension appears to have come from. */
145
146	#define DIRECTIVE_TABLE \
147	D(define, T_DEFINE = 0, KANDR, IN_I) \
148	D(include, T_INCLUDE, KANDR, INCL | EXPAND) \
149	D(endif, T_ENDIF, KANDR, COND) \
150	D(ifdef, T_IFDEF, KANDR, COND | IF_COND) \
151	D(if, T_IF, KANDR, COND | IF_COND | EXPAND) \
152	D(else, T_ELSE, KANDR, COND) \
153	D(ifndef, T_IFNDEF, KANDR, COND | IF_COND) \
154	D(undef, T_UNDEF, KANDR, IN_I) \
155	D(line, T_LINE, KANDR, EXPAND) \
156	D(elif, T_ELIF, STDC89, COND | EXPAND) \
157	D(elifdef, T_ELIFDEF, STDC23, COND | ELIFDEF) \
158	D(elifndef, T_ELIFNDEF, STDC23, COND | ELIFDEF) \
159	D(error, T_ERROR, STDC89, 0) \
160	D(pragma, T_PRAGMA, STDC89, IN_I) \
161	D(warning, T_WARNING, STDC23, 0) \
162	D(include_next, T_INCLUDE_NEXT, EXTENSION, INCL | EXPAND) \
163	D(ident, T_IDENT, EXTENSION, IN_I) \
164	D(import, T_IMPORT, EXTENSION, INCL | EXPAND) /* ObjC */ \
165	D(assert, T_ASSERT, EXTENSION, DEPRECATED) /* SVR4 */ \
166	D(unassert, T_UNASSERT, EXTENSION, DEPRECATED) /* SVR4 */ \
167	D(sccs, T_SCCS, EXTENSION, IN_I) /* SVR4? */
168
169	/* #sccs is synonymous with #ident. */
170	#define do_sccs do_ident
171
172	/* Use the table to generate a series of prototypes, an enum for the
173	directive names, and an array of directive handlers. */
174
175	#define D(name, t, o, f) static void do_##name (cpp_reader *);
176	DIRECTIVE_TABLE
177	#undef D
178
179	#define D(n, tag, o, f) tag,
180	enum
181	{
182	DIRECTIVE_TABLE
183	N_DIRECTIVES
184	};
185	#undef D
186
187	#define D(name, t, origin, flags) \
188	{ do_##name, (const uchar *) #name, \
189	sizeof #name - 1, origin, flags },
190	static const directive dtable[] =
191	{
192	DIRECTIVE_TABLE
193	};
194	#undef D
195
196	/* A NULL-terminated array of directive names for use
197	when suggesting corrections for misspelled directives. */
198	#define D(name, t, origin, flags) #name,
199	static const char * const directive_names[] = {
200	DIRECTIVE_TABLE
201	NULL
202	};
203	#undef D
204
205	#undef DIRECTIVE_TABLE
206
207	/* Wrapper struct directive for linemarkers.
208	The origin is more or less true - the original K+R cpp
209	did use this notation in its preprocessed output. */
210	static const directive linemarker_dir =
211	{
212	.handler: do_linemarker, UC"#", .length: 1, KANDR, IN_I
213	};
214
215	/* Skip any remaining tokens in a directive. */
216	static void
217	skip_rest_of_line (cpp_reader *pfile)
218	{
219	/* Discard all stacked contexts. */
220	while (pfile->context->prev)
221	_cpp_pop_context (pfile);
222
223	/* Sweep up all tokens remaining on the line. */
224	if (! SEEN_EOL ())
225	while (_cpp_lex_token (pfile)->type != CPP_EOF)
226	;
227	}
228
229	/* Helper function for check_oel. */
230
231	static void
232	check_eol_1 (cpp_reader *pfile, bool expand, enum cpp_warning_reason reason)
233	{
234	if (! SEEN_EOL () && (expand
235	? cpp_get_token (pfile)
236	: _cpp_lex_token (pfile))->type != CPP_EOF)
237	cpp_pedwarning (pfile, reason, msgid: "extra tokens at end of #%s directive",
238	pfile->directive->name);
239	}
240
241	/* Variant of check_eol used for Wendif-labels warnings. */
242
243	static void
244	check_eol_endif_labels (cpp_reader *pfile)
245	{
246	check_eol_1 (pfile, expand: false, reason: CPP_W_ENDIF_LABELS);
247	}
248
249	/* Ensure there are no stray tokens at the end of a directive. If
250	EXPAND is true, tokens macro-expanding to nothing are allowed. */
251
252	static void
253	check_eol (cpp_reader *pfile, bool expand)
254	{
255	check_eol_1 (pfile, expand, reason: CPP_W_NONE);
256	}
257
258	/* Ensure there are no stray tokens other than comments at the end of
259	a directive, and gather the comments. */
260	static const cpp_token **
261	check_eol_return_comments (cpp_reader *pfile)
262	{
263	size_t c;
264	size_t capacity = 8;
265	const cpp_token **buf;
266
267	buf = XNEWVEC (const cpp_token *, capacity);
268	c = 0;
269	if (! SEEN_EOL ())
270	{
271	while (1)
272	{
273	const cpp_token *tok;
274
275	tok = _cpp_lex_token (pfile);
276	if (tok->type == CPP_EOF)
277	break;
278	if (tok->type != CPP_COMMENT)
279	cpp_error (pfile, CPP_DL_PEDWARN,
280	msgid: "extra tokens at end of #%s directive",
281	pfile->directive->name);
282	else
283	{
284	if (c + 1 >= capacity)
285	{
286	capacity *= 2;
287	buf = XRESIZEVEC (const cpp_token *, buf, capacity);
288	}
289	buf[c] = tok;
290	++c;
291	}
292	}
293	}
294	buf[c] = NULL;
295	return buf;
296	}
297
298	/* Called when entering a directive, _Pragma or command-line directive. */
299	static void
300	start_directive (cpp_reader *pfile)
301	{
302	/* Setup in-directive state. */
303	pfile->state.in_directive = 1;
304	pfile->state.save_comments = 0;
305	pfile->directive_result.type = CPP_PADDING;
306
307	/* Some handlers need the position of the # for diagnostics. */
308	pfile->directive_line = pfile->line_table->highest_line;
309	}
310
311	/* Called when leaving a directive, _Pragma or command-line directive. */
312	static void
313	end_directive (cpp_reader *pfile, int skip_line)
314	{
315	if (CPP_OPTION (pfile, traditional))
316	{
317	/* Revert change of prepare_directive_trad. */
318	if (!pfile->state.in_deferred_pragma)
319	pfile->state.prevent_expansion--;
320
321	if (pfile->directive != &dtable[T_DEFINE])
322	_cpp_remove_overlay (pfile);
323	}
324	else if (pfile->state.in_deferred_pragma)
325	;
326	/* We don't skip for an assembler #. */
327	else if (skip_line)
328	{
329	skip_rest_of_line (pfile);
330	if (!pfile->keep_tokens)
331	{
332	pfile->cur_run = &pfile->base_run;
333	pfile->cur_token = pfile->base_run.base;
334	}
335	}
336
337	/* Restore state. */
338	pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
339	pfile->state.in_directive = 0;
340	pfile->state.in_expression = 0;
341	pfile->state.angled_headers = 0;
342	pfile->directive = 0;
343	}
344
345	/* Prepare to handle the directive in pfile->directive. */
346	static void
347	prepare_directive_trad (cpp_reader *pfile)
348	{
349	if (pfile->directive != &dtable[T_DEFINE])
350	{
351	bool no_expand = (pfile->directive
352	&& ! (pfile->directive->flags & EXPAND));
353	bool was_skipping = pfile->state.skipping;
354
355	pfile->state.in_expression = (pfile->directive == &dtable[T_IF]
356	|| pfile->directive == &dtable[T_ELIF]);
357	if (pfile->state.in_expression)
358	pfile->state.skipping = false;
359
360	if (no_expand)
361	pfile->state.prevent_expansion++;
362	_cpp_scan_out_logical_line (pfile, NULL, false);
363	if (no_expand)
364	pfile->state.prevent_expansion--;
365
366	pfile->state.skipping = was_skipping;
367	_cpp_overlay_buffer (pfile, pfile->out.base,
368	pfile->out.cur - pfile->out.base);
369	}
370
371	/* Stop ISO C from expanding anything. */
372	pfile->state.prevent_expansion++;
373	}
374
375	/* Output diagnostics for a directive DIR. INDENTED is nonzero if
376	the '#' was indented. */
377	static void
378	directive_diagnostics (cpp_reader *pfile, const directive *dir, int indented)
379	{
380	/* Issue -pedantic or deprecated warnings for extensions. We let
381	-pedantic take precedence if both are applicable. */
382	if (! pfile->state.skipping)
383	{
384	if (dir->origin == EXTENSION
385	&& !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc))
386	&& CPP_PEDANTIC (pfile))
387	cpp_error (pfile, CPP_DL_PEDWARN, msgid: "#%s is a GCC extension", dir->name);
388	else if (dir == &dtable[T_WARNING])
389	{
390	if (CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, warning_directive))
391	{
392	if (CPP_OPTION (pfile, cplusplus))
393	cpp_error (pfile, CPP_DL_PEDWARN,
394	msgid: "#%s before C++23 is a GCC extension", dir->name);
395	else
396	cpp_error (pfile, CPP_DL_PEDWARN,
397	msgid: "#%s before C23 is a GCC extension", dir->name);
398	}
399	else if (CPP_OPTION (pfile, cpp_warn_c11_c23_compat) > 0)
400	cpp_warning (pfile, CPP_W_C11_C23_COMPAT,
401	msgid: "#%s before C23 is a GCC extension", dir->name);
402	}
403	else if (((dir->flags & DEPRECATED) != 0
404	|| (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
405	&& CPP_OPTION (pfile, cpp_warn_deprecated))
406	cpp_warning (pfile, CPP_W_DEPRECATED,
407	msgid: "#%s is a deprecated GCC extension", dir->name);
408	}
409
410	/* Traditionally, a directive is ignored unless its # is in
411	column 1. Therefore in code intended to work with K+R
412	compilers, directives added by C89 must have their #
413	indented, and directives present in traditional C must not.
414	This is true even of directives in skipped conditional
415	blocks. #elif cannot be used at all. */
416	if (CPP_WTRADITIONAL (pfile))
417	{
418	if (dir == &dtable[T_ELIF])
419	cpp_warning (pfile, CPP_W_TRADITIONAL,
420	msgid: "suggest not using #elif in traditional C");
421	else if (indented && dir->origin == KANDR)
422	cpp_warning (pfile, CPP_W_TRADITIONAL,
423	msgid: "traditional C ignores #%s with the # indented",
424	dir->name);
425	else if (!indented && dir->origin != KANDR)
426	cpp_warning (pfile, CPP_W_TRADITIONAL,
427	msgid: "suggest hiding #%s from traditional C with an indented #",
428	dir->name);
429	}
430	}
431
432	/* Check if we have a known directive. INDENTED is true if the
433	'#' of the directive was indented. This function is in this file
434	to save unnecessarily exporting dtable etc. to lex.cc. Returns
435	nonzero if the line of tokens has been handled, zero if we should
436	continue processing the line. */
437	int
438	_cpp_handle_directive (cpp_reader *pfile, bool indented)
439	{
440	const directive *dir = 0;
441	const cpp_token *dname;
442	bool was_parsing_args = pfile->state.parsing_args;
443	bool was_discarding_output = pfile->state.discarding_output;
444	int skip = 1;
445
446	if (was_discarding_output)
447	pfile->state.prevent_expansion = 0;
448
449	if (was_parsing_args)
450	{
451	if (CPP_OPTION (pfile, cpp_pedantic))
452	cpp_error (pfile, CPP_DL_PEDWARN,
453	msgid: "embedding a directive within macro arguments is not portable");
454	pfile->state.parsing_args = 0;
455	pfile->state.prevent_expansion = 0;
456	}
457	start_directive (pfile);
458	dname = _cpp_lex_token (pfile);
459
460	if (dname->type == CPP_NAME)
461	{
462	if (dname->val.node.node->is_directive)
463	{
464	dir = &dtable[dname->val.node.node->directive_index];
465	if ((dir->flags & ELIFDEF)
466	&& !CPP_OPTION (pfile, elifdef)
467	/* For -std=gnu* modes elifdef is supported with
468	a pedwarn if pedantic. */
469	&& CPP_OPTION (pfile, std))
470	dir = 0;
471	}
472	}
473	/* We do not recognize the # followed by a number extension in
474	assembler code. */
475	else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM)
476	{
477	dir = &linemarker_dir;
478	if (CPP_PEDANTIC (pfile) && ! CPP_OPTION (pfile, preprocessed)
479	&& ! pfile->state.skipping)
480	cpp_error (pfile, CPP_DL_PEDWARN,
481	msgid: "style of line directive is a GCC extension");
482	}
483
484	if (dir)
485	{
486	/* If we have a directive that is not an opening conditional,
487	invalidate any control macro. */
488	if (! (dir->flags & IF_COND))
489	pfile->mi_valid = false;
490
491	/* Kluge alert. In order to be sure that code like this
492
493	#define HASH #
494	HASH define foo bar
495
496	does not cause '#define foo bar' to get executed when
497	compiled with -save-temps, we recognize directives in
498	-fpreprocessed mode only if the # is in column 1. macro.cc
499	puts a space in front of any '#' at the start of a macro.
500
501	We exclude the -fdirectives-only case because macro expansion
502	has not been performed yet, and block comments can cause spaces
503	to precede the directive. */
504	if (CPP_OPTION (pfile, preprocessed)
505	&& !CPP_OPTION (pfile, directives_only)
506	&& (indented || !(dir->flags & IN_I)))
507	{
508	skip = 0;
509	dir = 0;
510	}
511	else
512	{
513	/* In failed conditional groups, all non-conditional
514	directives are ignored. Before doing that, whether
515	skipping or not, we should lex angle-bracketed headers
516	correctly, and maybe output some diagnostics. */
517	pfile->state.angled_headers = dir->flags & INCL;
518	pfile->state.directive_wants_padding = dir->flags & INCL;
519	if (! CPP_OPTION (pfile, preprocessed))
520	directive_diagnostics (pfile, dir, indented);
521	if (pfile->state.skipping && !(dir->flags & COND))
522	dir = 0;
523	}
524	}
525	else if (dname->type == CPP_EOF)
526	; /* CPP_EOF is the "null directive". */
527	else
528	{
529	/* An unknown directive. Don't complain about it in assembly
530	source: we don't know where the comments are, and # may
531	introduce assembler pseudo-ops. Don't complain about invalid
532	directives in skipped conditional groups (6.10 p4). */
533	if (CPP_OPTION (pfile, lang) == CLK_ASM)
534	skip = 0;
535	else if (!pfile->state.skipping)
536	{
537	const char *unrecognized
538	= (const char *)cpp_token_as_text (pfile, dname);
539	const char *hint = NULL;
540
541	/* Call back into gcc to get a spelling suggestion. Ideally
542	we'd just use best_match from gcc/spellcheck.h (and filter
543	out the uncommon directives), but that requires moving it
544	to a support library. */
545	if (pfile->cb.get_suggestion)
546	hint = pfile->cb.get_suggestion (pfile, unrecognized,
547	directive_names);
548
549	if (hint)
550	{
551	rich_location richloc (pfile->line_table, dname->src_loc);
552	source_range misspelled_token_range
553	= get_range_from_loc (set: pfile->line_table, loc: dname->src_loc);
554	richloc.add_fixit_replace (src_range: misspelled_token_range, new_content: hint);
555	cpp_error_at (pfile, CPP_DL_ERROR, richloc: &richloc,
556	msgid: "invalid preprocessing directive #%s;"
557	" did you mean #%s?",
558	unrecognized, hint);
559	}
560	else
561	cpp_error (pfile, CPP_DL_ERROR,
562	msgid: "invalid preprocessing directive #%s",
563	unrecognized);
564	}
565	}
566
567	pfile->directive = dir;
568	if (CPP_OPTION (pfile, traditional))
569	prepare_directive_trad (pfile);
570
571	if (dir)
572	pfile->directive->handler (pfile);
573	else if (skip == 0)
574	_cpp_backup_tokens (pfile, 1);
575
576	end_directive (pfile, skip_line: skip);
577	if (was_parsing_args && !pfile->state.in_deferred_pragma)
578	{
579	/* Restore state when within macro args. */
580	pfile->state.parsing_args = 2;
581	pfile->state.prevent_expansion = 1;
582	}
583	if (was_discarding_output)
584	pfile->state.prevent_expansion = 1;
585	return skip;
586	}
587
588	/* Directive handler wrapper used by the command line option
589	processor. BUF is \n terminated. */
590	static void
591	run_directive (cpp_reader *pfile, int dir_no, const char *buf, size_t count)
592	{
593	cpp_push_buffer (pfile, (const uchar *) buf, count,
594	/* from_stage3 */ true);
595	start_directive (pfile);
596
597	/* This is a short-term fix to prevent a leading '#' being
598	interpreted as a directive. */
599	_cpp_clean_line (pfile);
600
601	pfile->directive = &dtable[dir_no];
602	if (CPP_OPTION (pfile, traditional))
603	prepare_directive_trad (pfile);
604	pfile->directive->handler (pfile);
605	end_directive (pfile, skip_line: 1);
606	_cpp_pop_buffer (pfile);
607	}
608
609	/* Checks for validity the macro name in #define, #undef, #ifdef and
610	#ifndef directives. IS_DEF_OR_UNDEF is true if this call is
611	processing a #define or #undefine directive, and false
612	otherwise. */
613	static cpp_hashnode *
614	lex_macro_node (cpp_reader *pfile, bool is_def_or_undef)
615	{
616	const cpp_token *token = _cpp_lex_token (pfile);
617
618	/* The token immediately after #define must be an identifier. That
619	identifier may not be "defined", per C99 6.10.8p4.
620	In C++, it may not be any of the "named operators" either,
621	per C++98 [lex.digraph], [lex.key].
622	Finally, the identifier may not have been poisoned. (In that case
623	the lexer has issued the error message for us.) */
624
625	if (token->type == CPP_NAME)
626	{
627	cpp_hashnode *node = token->val.node.node;
628
629	if (is_def_or_undef
630	&& node == pfile->spec_nodes.n_defined)
631	cpp_error (pfile, CPP_DL_ERROR,
632	msgid: "\"%s\" cannot be used as a macro name",
633	NODE_NAME (node));
634	else if (! (node->flags & NODE_POISONED))
635	return node;
636	}
637	else if (token->flags & NAMED_OP)
638	cpp_error (pfile, CPP_DL_ERROR,
639	msgid: "\"%s\" cannot be used as a macro name as it is an operator in C++",
640	NODE_NAME (token->val.node.node));
641	else if (token->type == CPP_EOF)
642	cpp_error (pfile, CPP_DL_ERROR, msgid: "no macro name given in #%s directive",
643	pfile->directive->name);
644	else
645	cpp_error (pfile, CPP_DL_ERROR, msgid: "macro names must be identifiers");
646
647	return NULL;
648	}
649
650	/* Process a #define directive. Most work is done in macro.cc. */
651	static void
652	do_define (cpp_reader *pfile)
653	{
654	cpp_hashnode *node = lex_macro_node (pfile, is_def_or_undef: true);
655
656	if (node)
657	{
658	/* This is a better location than pfile->directive_line to store
659	as the macro location. */
660	const location_t name_loc = cpp_diagnostic_get_current_location (pfile);
661
662	/* If we have been requested to expand comments into macros,
663	then re-enable saving of comments. */
664	pfile->state.save_comments =
665	! CPP_OPTION (pfile, discard_comments_in_macro_exp);
666
667	if (pfile->cb.before_define)
668	pfile->cb.before_define (pfile);
669
670	if (_cpp_create_definition (pfile, node, name_loc))
671	if (pfile->cb.define)
672	pfile->cb.define (pfile, pfile->directive_line, node);
673
674	node->flags &= ~NODE_USED;
675	}
676	}
677
678	/* Handle #undef. Mark the identifier NT_VOID in the hash table. */
679	static void
680	do_undef (cpp_reader *pfile)
681	{
682	cpp_hashnode *node = lex_macro_node (pfile, is_def_or_undef: true);
683
684	if (node)
685	{
686	if (pfile->cb.before_define)
687	pfile->cb.before_define (pfile);
688
689	if (pfile->cb.undef)
690	pfile->cb.undef (pfile, pfile->directive_line, node);
691
692	/* 6.10.3.5 paragraph 2: [#undef] is ignored if the specified
693	identifier is not currently defined as a macro name. */
694	if (cpp_macro_p (node))
695	{
696	if (node->flags & NODE_WARN)
697	cpp_error (pfile, CPP_DL_WARNING,
698	msgid: "undefining \"%s\"", NODE_NAME (node));
699	else if (cpp_builtin_macro_p (node)
700	&& CPP_OPTION (pfile, warn_builtin_macro_redefined))
701	cpp_warning (pfile, CPP_W_BUILTIN_MACRO_REDEFINED,
702	msgid: "undefining \"%s\"", NODE_NAME (node));
703
704	if (node->value.macro
705	&& CPP_OPTION (pfile, warn_unused_macros))
706	_cpp_warn_if_unused_macro (pfile, node, NULL);
707
708	_cpp_free_definition (node);
709	}
710	}
711
712	check_eol (pfile, expand: false);
713	}
714
715	/* Undefine a single macro/assertion/whatever. */
716
717	static int
718	undefine_macros (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *h,
719	void *data_p ATTRIBUTE_UNUSED)
720	{
721	/* Body of _cpp_free_definition inlined here for speed.
722	Macros and assertions no longer have anything to free. */
723	h->type = NT_VOID;
724	h->value.answers = NULL;
725	h->flags &= ~(NODE_POISONED|NODE_DISABLED|NODE_USED);
726	return 1;
727	}
728
729	/* Undefine all macros and assertions. */
730
731	void
732	cpp_undef_all (cpp_reader *pfile)
733	{
734	cpp_forall_identifiers (pfile, undefine_macros, NULL);
735	}
736
737
738	/* Helper routine used by parse_include. Reinterpret the current line
739	as an h-char-sequence (< ... >); we are looking at the first token
740	after the <. Returns a malloced filename. */
741	static char *
742	glue_header_name (cpp_reader *pfile)
743	{
744	const cpp_token *token;
745	char *buffer;
746	size_t len, total_len = 0, capacity = 1024;
747
748	/* To avoid lexed tokens overwriting our glued name, we can only
749	allocate from the string pool once we've lexed everything. */
750	buffer = XNEWVEC (char, capacity);
751	for (;;)
752	{
753	token = get_token_no_padding (pfile);
754
755	if (token->type == CPP_GREATER)
756	break;
757	if (token->type == CPP_EOF)
758	{
759	cpp_error (pfile, CPP_DL_ERROR, msgid: "missing terminating > character");
760	break;
761	}
762
763	len = cpp_token_len (token) + 2; /* Leading space, terminating \0. */
764	if (total_len + len > capacity)
765	{
766	capacity = (capacity + len) * 2;
767	buffer = XRESIZEVEC (char, buffer, capacity);
768	}
769
770	if (token->flags & PREV_WHITE)
771	buffer[total_len++] = ' ';
772
773	total_len = (cpp_spell_token (pfile, token, (uchar *) &buffer[total_len],
774	true)
775	- (uchar *) buffer);
776	}
777
778	buffer[total_len] = '\0';
779	return buffer;
780	}
781
782	/* Returns the file name of #include, #include_next, #import and
783	#pragma dependency. The string is malloced and the caller should
784	free it. Returns NULL on error. LOCATION is the source location
785	of the file name. */
786
787	static const char *
788	parse_include (cpp_reader *pfile, int *pangle_brackets,
789	const cpp_token ***buf, location_t *location)
790	{
791	char *fname;
792	const cpp_token *header;
793
794	/* Allow macro expansion. */
795	header = get_token_no_padding (pfile);
796	*location = header->src_loc;
797	if ((header->type == CPP_STRING && header->val.str.text[0] != 'R')
798	|| header->type == CPP_HEADER_NAME)
799	{
800	fname = XNEWVEC (char, header->val.str.len - 1);
801	memcpy (dest: fname, src: header->val.str.text + 1, n: header->val.str.len - 2);
802	fname[header->val.str.len - 2] = '\0';
803	*pangle_brackets = header->type == CPP_HEADER_NAME;
804	}
805	else if (header->type == CPP_LESS)
806	{
807	fname = glue_header_name (pfile);
808	*pangle_brackets = 1;
809	}
810	else
811	{
812	const unsigned char *dir;
813
814	if (pfile->directive == &dtable[T_PRAGMA])
815	dir = UC"pragma dependency";
816	else
817	dir = pfile->directive->name;
818	cpp_error (pfile, CPP_DL_ERROR, msgid: "#%s expects \"FILENAME\" or <FILENAME>",
819	dir);
820
821	return NULL;
822	}
823
824	if (pfile->directive == &dtable[T_PRAGMA])
825	{
826	/* This pragma allows extra tokens after the file name. */
827	}
828	else if (buf == NULL || CPP_OPTION (pfile, discard_comments))
829	check_eol (pfile, expand: true);
830	else
831	{
832	/* If we are not discarding comments, then gather them while
833	doing the eol check. */
834	*buf = check_eol_return_comments (pfile);
835	}
836
837	return fname;
838	}
839
840	/* Handle #include, #include_next and #import. */
841	static void
842	do_include_common (cpp_reader *pfile, enum include_type type)
843	{
844	const char *fname;
845	int angle_brackets;
846	const cpp_token **buf = NULL;
847	location_t location;
848
849	/* Re-enable saving of comments if requested, so that the include
850	callback can dump comments which follow #include. */
851	pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
852
853	/* Tell the lexer this is an include directive -- we want it to
854	increment the line number even if this is the last line of a file. */
855	pfile->state.in_directive = 2;
856
857	fname = parse_include (pfile, pangle_brackets: &angle_brackets, buf: &buf, location: &location);
858	if (!fname)
859	goto done;
860
861	if (!*fname)
862	{
863	cpp_error_with_line (pfile, CPP_DL_ERROR, location, 0,
864	msgid: "empty filename in #%s",
865	pfile->directive->name);
866	goto done;
867	}
868
869	/* Prevent #include recursion. */
870	if (pfile->line_table->depth >= CPP_OPTION (pfile, max_include_depth))
871	cpp_error (pfile,
872	CPP_DL_ERROR,
873	msgid: "#include nested depth %u exceeds maximum of %u"
874	" (use -fmax-include-depth=DEPTH to increase the maximum)",
875	pfile->line_table->depth,
876	CPP_OPTION (pfile, max_include_depth));
877	else
878	{
879	/* Get out of macro context, if we are. */
880	skip_rest_of_line (pfile);
881
882	if (pfile->cb.include)
883	pfile->cb.include (pfile, pfile->directive_line,
884	pfile->directive->name, fname, angle_brackets,
885	buf);
886
887	_cpp_stack_include (pfile, fname, angle_brackets, type, location);
888	}
889
890	done:
891	XDELETEVEC (fname);
892	if (buf)
893	XDELETEVEC (buf);
894	}
895
896	static void
897	do_include (cpp_reader *pfile)
898	{
899	do_include_common (pfile, type: IT_INCLUDE);
900	}
901
902	static void
903	do_import (cpp_reader *pfile)
904	{
905	do_include_common (pfile, type: IT_IMPORT);
906	}
907
908	static void
909	do_include_next (cpp_reader *pfile)
910	{
911	enum include_type type = IT_INCLUDE_NEXT;
912
913	/* If this is the primary source file, warn and use the normal
914	search logic. */
915	if (_cpp_in_main_source_file (pfile))
916	{
917	cpp_error (pfile, CPP_DL_WARNING,
918	msgid: "#include_next in primary source file");
919	type = IT_INCLUDE;
920	}
921	do_include_common (pfile, type);
922	}
923
924	/* Subroutine of do_linemarker. Read possible flags after file name.
925	LAST is the last flag seen; 0 if this is the first flag. Return the
926	flag if it is valid, 0 at the end of the directive. Otherwise
927	complain. */
928	static unsigned int
929	read_flag (cpp_reader *pfile, unsigned int last)
930	{
931	const cpp_token *token = _cpp_lex_token (pfile);
932
933	if (token->type == CPP_NUMBER && token->val.str.len == 1)
934	{
935	unsigned int flag = token->val.str.text[0] - '0';
936
937	if (flag > last && flag <= 4
938	&& (flag != 4 || last == 3)
939	&& (flag != 2 || last == 0))
940	return flag;
941	}
942
943	if (token->type != CPP_EOF)
944	cpp_error (pfile, CPP_DL_ERROR, msgid: "invalid flag \"%s\" in line directive",
945	cpp_token_as_text (pfile, token));
946	return 0;
947	}
948
949	/* Subroutine of do_line and do_linemarker. Convert a number in STR,
950	of length LEN, to binary; store it in NUMP, and return false if the
951	number was well-formed, true if not. WRAPPED is set to true if the
952	number did not fit into 'linenum_type'. */
953	static bool
954	strtolinenum (const uchar *str, size_t len, linenum_type *nump, bool *wrapped)
955	{
956	linenum_type reg = 0;
957
958	uchar c;
959	bool seen_digit_sep = false;
960	*wrapped = false;
961	while (len--)
962	{
963	c = *str++;
964	if (!seen_digit_sep && c == '\'' && len)
965	{
966	seen_digit_sep = true;
967	continue;
968	}
969	if (!ISDIGIT (c))
970	return true;
971	seen_digit_sep = false;
972	if (reg > ((linenum_type) -1) / 10)
973	*wrapped = true;
974	reg *= 10;
975	if (reg > ((linenum_type) -1) - (c - '0'))
976	*wrapped = true;
977	reg += c - '0';
978	}
979	*nump = reg;
980	return false;
981	}
982
983	/* Interpret #line command.
984	Note that the filename string (if any) is a true string constant
985	(escapes are interpreted). */
986	static void
987	do_line (cpp_reader *pfile)
988	{
989	class line_maps *line_table = pfile->line_table;
990	const line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (set: line_table);
991
992	/* skip_rest_of_line() may cause line table to be realloc()ed so note down
993	sysp right now. */
994
995	unsigned char map_sysp = ORDINARY_MAP_IN_SYSTEM_HEADER_P (ord_map: map);
996	const cpp_token *token;
997	const char *new_file = ORDINARY_MAP_FILE_NAME (ord_map: map);
998	linenum_type new_lineno;
999
1000	/* C99 raised the minimum limit on #line numbers. */
1001	linenum_type cap = CPP_OPTION (pfile, c99) ? 2147483647 : 32767;
1002	bool wrapped;
1003
1004	/* #line commands expand macros. */
1005	token = cpp_get_token (pfile);
1006	if (token->type != CPP_NUMBER
1007	|| strtolinenum (str: token->val.str.text, len: token->val.str.len,
1008	nump: &new_lineno, wrapped: &wrapped))
1009	{
1010	if (token->type == CPP_EOF)
1011	cpp_error (pfile, CPP_DL_ERROR, msgid: "unexpected end of file after #line");
1012	else
1013	cpp_error (pfile, CPP_DL_ERROR,
1014	msgid: "\"%s\" after #line is not a positive integer",
1015	cpp_token_as_text (pfile, token));
1016	return;
1017	}
1018
1019	if (CPP_PEDANTIC (pfile) && (new_lineno == 0 || new_lineno > cap || wrapped))
1020	cpp_error (pfile, CPP_DL_PEDWARN, msgid: "line number out of range");
1021	else if (wrapped)
1022	cpp_error (pfile, CPP_DL_WARNING, msgid: "line number out of range");
1023
1024	token = cpp_get_token (pfile);
1025	if (token->type == CPP_STRING)
1026	{
1027	cpp_string s = { .len: 0, .text: 0 };
1028	if (cpp_interpret_string_notranslate (pfile, &token->val.str, 1,
1029	&s, CPP_STRING))
1030	new_file = (const char *)s.text;
1031	check_eol (pfile, expand: true);
1032	}
1033	else if (token->type != CPP_EOF)
1034	{
1035	cpp_error (pfile, CPP_DL_ERROR, msgid: "\"%s\" is not a valid filename",
1036	cpp_token_as_text (pfile, token));
1037	return;
1038	}
1039
1040	skip_rest_of_line (pfile);
1041	_cpp_do_file_change (pfile, LC_RENAME_VERBATIM, new_file, new_lineno,
1042	map_sysp);
1043	line_table->seen_line_directive = true;
1044	}
1045
1046	/* Interpret the # 44 "file" [flags] notation, which has slightly
1047	different syntax and semantics from #line: Flags are allowed,
1048	and we never complain about the line number being too big. */
1049	static void
1050	do_linemarker (cpp_reader *pfile)
1051	{
1052	class line_maps *line_table = pfile->line_table;
1053	const line_map_ordinary *map = LINEMAPS_LAST_ORDINARY_MAP (set: line_table);
1054	const cpp_token *token;
1055	const char *new_file = ORDINARY_MAP_FILE_NAME (ord_map: map);
1056	linenum_type new_lineno;
1057	unsigned int new_sysp = ORDINARY_MAP_IN_SYSTEM_HEADER_P (ord_map: map);
1058	enum lc_reason reason = LC_RENAME_VERBATIM;
1059	int flag;
1060	bool wrapped;
1061
1062	/* Back up so we can get the number again. Putting this in
1063	_cpp_handle_directive risks two calls to _cpp_backup_tokens in
1064	some circumstances, which can segfault. */
1065	_cpp_backup_tokens (pfile, 1);
1066
1067	/* #line commands expand macros. */
1068	token = cpp_get_token (pfile);
1069	if (token->type != CPP_NUMBER
1070	|| strtolinenum (str: token->val.str.text, len: token->val.str.len,
1071	nump: &new_lineno, wrapped: &wrapped))
1072	{
1073	/* Unlike #line, there does not seem to be a way to get an EOF
1074	here. So, it should be safe to always spell the token. */
1075	cpp_error (pfile, CPP_DL_ERROR,
1076	msgid: "\"%s\" after # is not a positive integer",
1077	cpp_token_as_text (pfile, token));
1078	return;
1079	}
1080
1081	token = cpp_get_token (pfile);
1082	if (token->type == CPP_STRING)
1083	{
1084	cpp_string s = { .len: 0, .text: 0 };
1085	if (cpp_interpret_string_notranslate (pfile, &token->val.str,
1086	1, &s, CPP_STRING))
1087	new_file = (const char *)s.text;
1088
1089	new_sysp = 0;
1090	flag = read_flag (pfile, last: 0);
1091	if (flag == 1)
1092	{
1093	reason = LC_ENTER;
1094	/* Fake an include for cpp_included (). */
1095	_cpp_fake_include (pfile, new_file);
1096	flag = read_flag (pfile, last: flag);
1097	}
1098	else if (flag == 2)
1099	{
1100	reason = LC_LEAVE;
1101	flag = read_flag (pfile, last: flag);
1102	}
1103	if (flag == 3)
1104	{
1105	new_sysp = 1;
1106	flag = read_flag (pfile, last: flag);
1107	if (flag == 4)
1108	new_sysp = 2;
1109	}
1110	pfile->buffer->sysp = new_sysp;
1111
1112	check_eol (pfile, expand: false);
1113	}
1114	else if (token->type != CPP_EOF)
1115	{
1116	cpp_error (pfile, CPP_DL_ERROR, msgid: "\"%s\" is not a valid filename",
1117	cpp_token_as_text (pfile, token));
1118	return;
1119	}
1120
1121	skip_rest_of_line (pfile);
1122
1123	if (reason == LC_LEAVE)
1124	{
1125	/* Reread map since cpp_get_token can invalidate it with a
1126	reallocation. */
1127	map = LINEMAPS_LAST_ORDINARY_MAP (set: line_table);
1128	const line_map_ordinary *from
1129	= linemap_included_from_linemap (set: line_table, map);
1130
1131	if (!from)
1132	/* Not nested. */;
1133	else if (!new_file[0])
1134	/* Leaving to "" means fill in the popped-to name. */
1135	new_file = ORDINARY_MAP_FILE_NAME (ord_map: from);
1136	else if (filename_cmp (s1: ORDINARY_MAP_FILE_NAME (ord_map: from), s2: new_file) != 0)
1137	/* It's the wrong name, Grommit! */
1138	from = NULL;
1139
1140	if (!from)
1141	{
1142	cpp_warning (pfile, CPP_W_NONE,
1143	msgid: "file \"%s\" linemarker ignored due to "
1144	"incorrect nesting", new_file);
1145	return;
1146	}
1147	}
1148
1149	/* Compensate for the increment in linemap_add that occurs in
1150	_cpp_do_file_change. We're currently at the start of the line
1151	*following* the #line directive. A separate location_t for this
1152	location makes no sense (until we do the LC_LEAVE), and
1153	complicates LAST_SOURCE_LINE_LOCATION. */
1154	pfile->line_table->highest_location--;
1155
1156	_cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp);
1157	line_table->seen_line_directive = true;
1158	}
1159
1160	/* Arrange the file_change callback. Changing to TO_FILE:TO_LINE for
1161	REASON. SYSP is 1 for a system header, 2 for a system header that
1162	needs to be extern "C" protected, and zero otherwise. */
1163	void
1164	_cpp_do_file_change (cpp_reader *pfile, enum lc_reason reason,
1165	const char *to_file, linenum_type to_line,
1166	unsigned int sysp)
1167	{
1168	linemap_assert (reason != LC_ENTER_MACRO);
1169
1170	const line_map_ordinary *ord_map = NULL;
1171	if (!to_line && reason == LC_RENAME_VERBATIM)
1172	{
1173	/* A linemarker moving to line zero. If we're on the second
1174	line of the current map, and it also starts at zero, just
1175	rewind -- we're probably reading the builtins of a
1176	preprocessed source. */
1177	line_map_ordinary *last = LINEMAPS_LAST_ORDINARY_MAP (set: pfile->line_table);
1178	if (!ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map: last)
1179	&& 0 == filename_cmp (s1: to_file, s2: ORDINARY_MAP_FILE_NAME (ord_map: last))
1180	&& SOURCE_LINE (ord_map: last, loc: pfile->line_table->highest_line) == 2)
1181	{
1182	ord_map = last;
1183	pfile->line_table->highest_location
1184	= pfile->line_table->highest_line = MAP_START_LOCATION (map: last);
1185	}
1186	}
1187
1188	if (!ord_map)
1189	if (const line_map *map = linemap_add (pfile->line_table, reason, sysp,
1190	to_file, to_line))
1191	{
1192	ord_map = linemap_check_ordinary (map);
1193	linemap_line_start (set: pfile->line_table,
1194	to_line: ORDINARY_MAP_STARTING_LINE_NUMBER (ord_map),
1195	max_column_hint: 127);
1196	}
1197
1198	if (pfile->cb.file_change)
1199	pfile->cb.file_change (pfile, ord_map);
1200	}
1201
1202	/* Report a warning or error detected by the program we are
1203	processing. Use the directive's tokens in the error message. */
1204	static void
1205	do_diagnostic (cpp_reader *pfile, enum cpp_diagnostic_level code,
1206	enum cpp_warning_reason reason, int print_dir)
1207	{
1208	const unsigned char *dir_name;
1209	unsigned char *line;
1210	location_t src_loc = pfile->cur_token[-1].src_loc;
1211
1212	if (print_dir)
1213	dir_name = pfile->directive->name;
1214	else
1215	dir_name = NULL;
1216	pfile->state.prevent_expansion++;
1217	line = cpp_output_line_to_string (pfile, dir_name);
1218	pfile->state.prevent_expansion--;
1219
1220	if (code == CPP_DL_WARNING_SYSHDR && reason)
1221	cpp_warning_with_line_syshdr (pfile, reason, src_loc, 0, msgid: "%s", line);
1222	else if (code == CPP_DL_WARNING && reason)
1223	cpp_warning_with_line (pfile, reason, src_loc, 0, msgid: "%s", line);
1224	else
1225	cpp_error_with_line (pfile, code, src_loc, 0, msgid: "%s", line);
1226	free (ptr: line);
1227	}
1228
1229	static void
1230	do_error (cpp_reader *pfile)
1231	{
1232	do_diagnostic (pfile, code: CPP_DL_ERROR, reason: CPP_W_NONE, print_dir: 1);
1233	}
1234
1235	static void
1236	do_warning (cpp_reader *pfile)
1237	{
1238	/* We want #warning diagnostics to be emitted in system headers too. */
1239	do_diagnostic (pfile, code: CPP_DL_WARNING_SYSHDR, reason: CPP_W_WARNING_DIRECTIVE, print_dir: 1);
1240	}
1241
1242	/* Report program identification. */
1243	static void
1244	do_ident (cpp_reader *pfile)
1245	{
1246	const cpp_token *str = cpp_get_token (pfile);
1247
1248	if (str->type != CPP_STRING)
1249	cpp_error (pfile, CPP_DL_ERROR, msgid: "invalid #%s directive",
1250	pfile->directive->name);
1251	else if (pfile->cb.ident)
1252	pfile->cb.ident (pfile, pfile->directive_line, &str->val.str);
1253
1254	check_eol (pfile, expand: false);
1255	}
1256
1257	/* Lookup a PRAGMA name in a singly-linked CHAIN. Returns the
1258	matching entry, or NULL if none is found. The returned entry could
1259	be the start of a namespace chain, or a pragma. */
1260	static struct pragma_entry *
1261	lookup_pragma_entry (struct pragma_entry *chain, const cpp_hashnode *pragma)
1262	{
1263	while (chain && chain->pragma != pragma)
1264	chain = chain->next;
1265
1266	return chain;
1267	}
1268
1269	/* Create and insert a blank pragma entry at the beginning of a
1270	singly-linked CHAIN. */
1271	static struct pragma_entry *
1272	new_pragma_entry (cpp_reader *pfile, struct pragma_entry **chain)
1273	{
1274	struct pragma_entry *new_entry;
1275
1276	new_entry = (struct pragma_entry *)
1277	_cpp_aligned_alloc (pfile, sizeof (struct pragma_entry));
1278
1279	memset (s: new_entry, c: 0, n: sizeof (struct pragma_entry));
1280	new_entry->next = *chain;
1281
1282	*chain = new_entry;
1283	return new_entry;
1284	}
1285
1286	/* Register a pragma NAME in namespace SPACE. If SPACE is null, it
1287	goes in the global namespace. */
1288	static struct pragma_entry *
1289	register_pragma_1 (cpp_reader *pfile, const char *space, const char *name,
1290	bool allow_name_expansion)
1291	{
1292	struct pragma_entry **chain = &pfile->pragmas;
1293	struct pragma_entry *entry;
1294	const cpp_hashnode *node;
1295
1296	if (space)
1297	{
1298	node = cpp_lookup (pfile, UC space, strlen (s: space));
1299	entry = lookup_pragma_entry (chain: *chain, pragma: node);
1300	if (!entry)
1301	{
1302	entry = new_pragma_entry (pfile, chain);
1303	entry->pragma = node;
1304	entry->is_nspace = true;
1305	entry->allow_expansion = allow_name_expansion;
1306	}
1307	else if (!entry->is_nspace)
1308	goto clash;
1309	else if (entry->allow_expansion != allow_name_expansion)
1310	{
1311	cpp_error (pfile, CPP_DL_ICE,
1312	msgid: "registering pragmas in namespace \"%s\" with mismatched "
1313	"name expansion", space);
1314	return NULL;
1315	}
1316	chain = &entry->u.space;
1317	}
1318	else if (allow_name_expansion)
1319	{
1320	cpp_error (pfile, CPP_DL_ICE,
1321	msgid: "registering pragma \"%s\" with name expansion "
1322	"and no namespace", name);
1323	return NULL;
1324	}
1325
1326	/* Check for duplicates. */
1327	node = cpp_lookup (pfile, UC name, strlen (s: name));
1328	entry = lookup_pragma_entry (chain: *chain, pragma: node);
1329	if (entry == NULL)
1330	{
1331	entry = new_pragma_entry (pfile, chain);
1332	entry->pragma = node;
1333	return entry;
1334	}
1335
1336	if (entry->is_nspace)
1337	clash:
1338	cpp_error (pfile, CPP_DL_ICE,
1339	msgid: "registering \"%s\" as both a pragma and a pragma namespace",
1340	NODE_NAME (node));
1341	else if (space)
1342	cpp_error (pfile, CPP_DL_ICE, msgid: "#pragma %s %s is already registered",
1343	space, name);
1344	else
1345	cpp_error (pfile, CPP_DL_ICE, msgid: "#pragma %s is already registered", name);
1346
1347	return NULL;
1348	}
1349
1350	/* Register a cpplib internal pragma SPACE NAME with HANDLER. */
1351	static void
1352	register_pragma_internal (cpp_reader *pfile, const char *space,
1353	const char *name, pragma_cb handler)
1354	{
1355	struct pragma_entry *entry;
1356
1357	entry = register_pragma_1 (pfile, space, name, allow_name_expansion: false);
1358	entry->is_internal = true;
1359	entry->u.handler = handler;
1360	}
1361
1362	/* Register a pragma NAME in namespace SPACE. If SPACE is null, it
1363	goes in the global namespace. HANDLER is the handler it will call,
1364	which must be non-NULL. If ALLOW_EXPANSION is set, allow macro
1365	expansion while parsing pragma NAME. This function is exported
1366	from libcpp. */
1367	void
1368	cpp_register_pragma (cpp_reader *pfile, const char *space, const char *name,
1369	pragma_cb handler, bool allow_expansion)
1370	{
1371	struct pragma_entry *entry;
1372
1373	if (!handler)
1374	{
1375	cpp_error (pfile, CPP_DL_ICE, msgid: "registering pragma with NULL handler");
1376	return;
1377	}
1378
1379	entry = register_pragma_1 (pfile, space, name, allow_name_expansion: false);
1380	if (entry)
1381	{
1382	entry->allow_expansion = allow_expansion;
1383	entry->u.handler = handler;
1384	}
1385	}
1386
1387	/* Similarly, but create mark the pragma for deferred processing.
1388	When found, a CPP_PRAGMA token will be insertted into the stream
1389	with IDENT in the token->u.pragma slot. */
1390	void
1391	cpp_register_deferred_pragma (cpp_reader *pfile, const char *space,
1392	const char *name, unsigned int ident,
1393	bool allow_expansion, bool allow_name_expansion)
1394	{
1395	struct pragma_entry *entry;
1396
1397	entry = register_pragma_1 (pfile, space, name, allow_name_expansion);
1398	if (entry)
1399	{
1400	entry->is_deferred = true;
1401	entry->allow_expansion = allow_expansion;
1402	entry->u.ident = ident;
1403	}
1404	}
1405
1406	/* Register the pragmas the preprocessor itself handles. */
1407	void
1408	_cpp_init_internal_pragmas (cpp_reader *pfile)
1409	{
1410	/* Pragmas in the global namespace. */
1411	register_pragma_internal (pfile, space: 0, name: "once", handler: do_pragma_once);
1412	register_pragma_internal (pfile, space: 0, name: "push_macro", handler: do_pragma_push_macro);
1413	register_pragma_internal (pfile, space: 0, name: "pop_macro", handler: do_pragma_pop_macro);
1414
1415	/* New GCC-specific pragmas should be put in the GCC namespace. */
1416	register_pragma_internal (pfile, space: "GCC", name: "poison", handler: do_pragma_poison);
1417	register_pragma_internal (pfile, space: "GCC", name: "system_header",
1418	handler: do_pragma_system_header);
1419	register_pragma_internal (pfile, space: "GCC", name: "dependency", handler: do_pragma_dependency);
1420	register_pragma_internal (pfile, space: "GCC", name: "warning", handler: do_pragma_warning);
1421	register_pragma_internal (pfile, space: "GCC", name: "error", handler: do_pragma_error);
1422	}
1423
1424	/* Return the number of registered pragmas in PE. */
1425
1426	static int
1427	count_registered_pragmas (struct pragma_entry *pe)
1428	{
1429	int ct = 0;
1430	for (; pe != NULL; pe = pe->next)
1431	{
1432	if (pe->is_nspace)
1433	ct += count_registered_pragmas (pe: pe->u.space);
1434	ct++;
1435	}
1436	return ct;
1437	}
1438
1439	/* Save into SD the names of the registered pragmas referenced by PE,
1440	and return a pointer to the next free space in SD. */
1441
1442	static char **
1443	save_registered_pragmas (struct pragma_entry *pe, char **sd)
1444	{
1445	for (; pe != NULL; pe = pe->next)
1446	{
1447	if (pe->is_nspace)
1448	sd = save_registered_pragmas (pe: pe->u.space, sd);
1449	*sd++ = (char *) xmemdup (HT_STR (&pe->pragma->ident),
1450	HT_LEN (&pe->pragma->ident),
1451	HT_LEN (&pe->pragma->ident) + 1);
1452	}
1453	return sd;
1454	}
1455
1456	/* Return a newly-allocated array which saves the names of the
1457	registered pragmas. */
1458
1459	char **
1460	_cpp_save_pragma_names (cpp_reader *pfile)
1461	{
1462	int ct = count_registered_pragmas (pe: pfile->pragmas);
1463	char **result = XNEWVEC (char *, ct);
1464	(void) save_registered_pragmas (pe: pfile->pragmas, sd: result);
1465	return result;
1466	}
1467
1468	/* Restore from SD the names of the registered pragmas referenced by PE,
1469	and return a pointer to the next unused name in SD. */
1470
1471	static char **
1472	restore_registered_pragmas (cpp_reader *pfile, struct pragma_entry *pe,
1473	char **sd)
1474	{
1475	for (; pe != NULL; pe = pe->next)
1476	{
1477	if (pe->is_nspace)
1478	sd = restore_registered_pragmas (pfile, pe: pe->u.space, sd);
1479	pe->pragma = cpp_lookup (pfile, UC *sd, strlen (s: *sd));
1480	free (ptr: *sd);
1481	sd++;
1482	}
1483	return sd;
1484	}
1485
1486	/* Restore the names of the registered pragmas from SAVED. */
1487
1488	void
1489	_cpp_restore_pragma_names (cpp_reader *pfile, char **saved)
1490	{
1491	(void) restore_registered_pragmas (pfile, pe: pfile->pragmas, sd: saved);
1492	free (ptr: saved);
1493	}
1494
1495	/* Pragmata handling. We handle some, and pass the rest on to the
1496	front end. C99 defines three pragmas and says that no macro
1497	expansion is to be performed on them; whether or not macro
1498	expansion happens for other pragmas is implementation defined.
1499	This implementation allows for a mix of both, since GCC did not
1500	traditionally macro expand its (few) pragmas, whereas OpenMP
1501	specifies that macro expansion should happen. */
1502	static void
1503	do_pragma (cpp_reader *pfile)
1504	{
1505	const struct pragma_entry *p = NULL;
1506	const cpp_token *token, *pragma_token;
1507	location_t pragma_token_virt_loc = 0;
1508	cpp_token ns_token;
1509	unsigned int count = 1;
1510
1511	pfile->state.prevent_expansion++;
1512
1513	pragma_token = token = cpp_get_token_with_location (pfile,
1514	&pragma_token_virt_loc);
1515	ns_token = *token;
1516	if (token->type == CPP_NAME)
1517	{
1518	p = lookup_pragma_entry (chain: pfile->pragmas, pragma: token->val.node.node);
1519	if (p && p->is_nspace)
1520	{
1521	bool allow_name_expansion = p->allow_expansion;
1522	if (allow_name_expansion)
1523	pfile->state.prevent_expansion--;
1524
1525	token = cpp_get_token (pfile);
1526	if (token->type == CPP_NAME)
1527	p = lookup_pragma_entry (chain: p->u.space, pragma: token->val.node.node);
1528	else
1529	p = NULL;
1530	if (allow_name_expansion)
1531	pfile->state.prevent_expansion++;
1532	count = 2;
1533	}
1534	}
1535
1536	if (p)
1537	{
1538	if (p->is_deferred)
1539	{
1540	pfile->directive_result.src_loc = pragma_token_virt_loc;
1541	pfile->directive_result.type = CPP_PRAGMA;
1542	pfile->directive_result.flags = pragma_token->flags;
1543	pfile->directive_result.val.pragma = p->u.ident;
1544	pfile->state.in_deferred_pragma = true;
1545	pfile->state.pragma_allow_expansion = p->allow_expansion;
1546	if (!p->allow_expansion)
1547	pfile->state.prevent_expansion++;
1548	}
1549	else
1550	{
1551	/* Since the handler below doesn't get the line number, that
1552	it might need for diagnostics, make sure it has the right
1553	numbers in place. */
1554	if (pfile->cb.line_change)
1555	(*pfile->cb.line_change) (pfile, pragma_token, false);
1556	if (p->allow_expansion)
1557	pfile->state.prevent_expansion--;
1558	(*p->u.handler) (pfile);
1559	if (p->allow_expansion)
1560	pfile->state.prevent_expansion++;
1561	}
1562	}
1563	else if (pfile->cb.def_pragma)
1564	{
1565	if (count == 1 || pfile->context->prev == NULL)
1566	_cpp_backup_tokens (pfile, count);
1567	else
1568	{
1569	/* Invalid name comes from macro expansion, _cpp_backup_tokens
1570	won't allow backing 2 tokens. */
1571	const auto tok_buff = _cpp_get_buff (pfile, 2 * sizeof (cpp_token));
1572	const auto toks = (cpp_token *)tok_buff->base;
1573	toks[0] = ns_token;
1574	toks[0].flags |= NO_EXPAND;
1575	toks[1] = *token;
1576	toks[1].flags |= NO_EXPAND | PREV_WHITE;
1577	_cpp_push_token_context (pfile, NULL, toks, 2);
1578	/* Arrange to free this buffer when no longer needed. */
1579	pfile->context->buff = tok_buff;
1580	}
1581	pfile->cb.def_pragma (pfile, pfile->directive_line);
1582	}
1583
1584	pfile->state.prevent_expansion--;
1585	}
1586
1587	/* Handle #pragma once. */
1588	static void
1589	do_pragma_once (cpp_reader *pfile)
1590	{
1591	if (_cpp_in_main_source_file (pfile))
1592	cpp_error (pfile, CPP_DL_WARNING, msgid: "#pragma once in main file");
1593
1594	check_eol (pfile, expand: false);
1595	_cpp_mark_file_once_only (pfile, pfile->buffer->file);
1596	}
1597
1598	/* Handle #pragma push_macro(STRING). */
1599	static void
1600	do_pragma_push_macro (cpp_reader *pfile)
1601	{
1602	cpp_hashnode *node;
1603	size_t defnlen;
1604	const uchar *defn = NULL;
1605	char *macroname, *dest;
1606	const char *limit, *src;
1607	const cpp_token *txt;
1608	struct def_pragma_macro *c;
1609
1610	txt = get__Pragma_string (pfile);
1611	if (!txt)
1612	{
1613	location_t src_loc = pfile->cur_token[-1].src_loc;
1614	cpp_error_with_line (pfile, CPP_DL_ERROR, src_loc, 0,
1615	msgid: "invalid #pragma push_macro directive");
1616	check_eol (pfile, expand: false);
1617	skip_rest_of_line (pfile);
1618	return;
1619	}
1620	dest = macroname = (char *) alloca (txt->val.str.len + 2);
1621	src = (const char *) (txt->val.str.text + 1 + (txt->val.str.text[0] == 'L'));
1622	limit = (const char *) (txt->val.str.text + txt->val.str.len - 1);
1623	while (src < limit)
1624	{
1625	/* We know there is a character following the backslash. */
1626	if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
1627	src++;
1628	*dest++ = *src++;
1629	}
1630	*dest = 0;
1631	check_eol (pfile, expand: false);
1632	skip_rest_of_line (pfile);
1633	c = XNEW (struct def_pragma_macro);
1634	memset (s: c, c: 0, n: sizeof (struct def_pragma_macro));
1635	c->name = XNEWVAR (char, strlen (macroname) + 1);
1636	strcpy (dest: c->name, src: macroname);
1637	c->next = pfile->pushed_macros;
1638	node = _cpp_lex_identifier (pfile, c->name);
1639	if (node->type == NT_VOID)
1640	c->is_undef = 1;
1641	else if (node->type == NT_BUILTIN_MACRO)
1642	c->is_builtin = 1;
1643	else
1644	{
1645	defn = cpp_macro_definition (pfile, node);
1646	defnlen = ustrlen (s1: defn);
1647	c->definition = XNEWVEC (uchar, defnlen + 2);
1648	c->definition[defnlen] = '\n';
1649	c->definition[defnlen + 1] = 0;
1650	c->line = node->value.macro->line;
1651	c->syshdr = node->value.macro->syshdr;
1652	c->used = node->value.macro->used;
1653	memcpy (dest: c->definition, src: defn, n: defnlen);
1654	}
1655
1656	pfile->pushed_macros = c;
1657	}
1658
1659	/* Handle #pragma pop_macro(STRING). */
1660	static void
1661	do_pragma_pop_macro (cpp_reader *pfile)
1662	{
1663	char *macroname, *dest;
1664	const char *limit, *src;
1665	const cpp_token *txt;
1666	struct def_pragma_macro *l = NULL, *c = pfile->pushed_macros;
1667	txt = get__Pragma_string (pfile);
1668	if (!txt)
1669	{
1670	location_t src_loc = pfile->cur_token[-1].src_loc;
1671	cpp_error_with_line (pfile, CPP_DL_ERROR, src_loc, 0,
1672	msgid: "invalid #pragma pop_macro directive");
1673	check_eol (pfile, expand: false);
1674	skip_rest_of_line (pfile);
1675	return;
1676	}
1677	dest = macroname = (char *) alloca (txt->val.str.len + 2);
1678	src = (const char *) (txt->val.str.text + 1 + (txt->val.str.text[0] == 'L'));
1679	limit = (const char *) (txt->val.str.text + txt->val.str.len - 1);
1680	while (src < limit)
1681	{
1682	/* We know there is a character following the backslash. */
1683	if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
1684	src++;
1685	*dest++ = *src++;
1686	}
1687	*dest = 0;
1688	check_eol (pfile, expand: false);
1689	skip_rest_of_line (pfile);
1690
1691	while (c != NULL)
1692	{
1693	if (!strcmp (s1: c->name, s2: macroname))
1694	{
1695	if (!l)
1696	pfile->pushed_macros = c->next;
1697	else
1698	l->next = c->next;
1699	cpp_pop_definition (pfile, c);
1700	free (ptr: c->definition);
1701	free (ptr: c->name);
1702	free (ptr: c);
1703	break;
1704	}
1705	l = c;
1706	c = c->next;
1707	}
1708	}
1709
1710	/* Handle #pragma GCC poison, to poison one or more identifiers so
1711	that the lexer produces a hard error for each subsequent usage. */
1712	static void
1713	do_pragma_poison (cpp_reader *pfile)
1714	{
1715	const cpp_token *tok;
1716	cpp_hashnode *hp;
1717
1718	pfile->state.poisoned_ok = 1;
1719	for (;;)
1720	{
1721	tok = _cpp_lex_token (pfile);
1722	if (tok->type == CPP_EOF)
1723	break;
1724	if (tok->type != CPP_NAME)
1725	{
1726	cpp_error (pfile, CPP_DL_ERROR,
1727	msgid: "invalid #pragma GCC poison directive");
1728	break;
1729	}
1730
1731	hp = tok->val.node.node;
1732	if (hp->flags & NODE_POISONED)
1733	continue;
1734
1735	if (cpp_macro_p (node: hp))
1736	cpp_error (pfile, CPP_DL_WARNING, msgid: "poisoning existing macro \"%s\"",
1737	NODE_NAME (hp));
1738	_cpp_free_definition (hp);
1739	hp->flags |= NODE_POISONED | NODE_DIAGNOSTIC;
1740	const auto data = (cpp_hashnode_extra *)
1741	ht_lookup (ht: pfile->extra_hash_table, id: hp->ident, opt: HT_ALLOC);
1742	data->poisoned_loc = tok->src_loc;
1743	}
1744	pfile->state.poisoned_ok = 0;
1745	}
1746
1747	/* Mark the current header as a system header. This will suppress
1748	some categories of warnings (notably those from -pedantic). It is
1749	intended for use in system libraries that cannot be implemented in
1750	conforming C, but cannot be certain that their headers appear in a
1751	system include directory. To prevent abuse, it is rejected in the
1752	primary source file. */
1753	static void
1754	do_pragma_system_header (cpp_reader *pfile)
1755	{
1756	if (_cpp_in_main_source_file (pfile))
1757	cpp_error (pfile, CPP_DL_WARNING,
1758	msgid: "#pragma system_header ignored outside include file");
1759	else
1760	{
1761	check_eol (pfile, expand: false);
1762	skip_rest_of_line (pfile);
1763	cpp_make_system_header (pfile, 1, 0);
1764	}
1765	}
1766
1767	/* Check the modified date of the current include file against a specified
1768	file. Issue a diagnostic, if the specified file is newer. We use this to
1769	determine if a fixed header should be refixed. */
1770	static void
1771	do_pragma_dependency (cpp_reader *pfile)
1772	{
1773	const char *fname;
1774	int angle_brackets, ordering;
1775	location_t location;
1776
1777	fname = parse_include (pfile, pangle_brackets: &angle_brackets, NULL, location: &location);
1778	if (!fname)
1779	return;
1780
1781	ordering = _cpp_compare_file_date (pfile, fname, angle_brackets);
1782	if (ordering < 0)
1783	cpp_error (pfile, CPP_DL_WARNING, msgid: "cannot find source file %s", fname);
1784	else if (ordering > 0)
1785	{
1786	cpp_error (pfile, CPP_DL_WARNING,
1787	msgid: "current file is older than %s", fname);
1788	if (cpp_get_token (pfile)->type != CPP_EOF)
1789	{
1790	_cpp_backup_tokens (pfile, 1);
1791	do_diagnostic (pfile, code: CPP_DL_WARNING, reason: CPP_W_NONE, print_dir: 0);
1792	}
1793	}
1794
1795	free (ptr: (void *) fname);
1796	}
1797
1798	/* Issue a diagnostic with the message taken from the pragma. If
1799	ERROR is true, the diagnostic is a warning, otherwise, it is an
1800	error. */
1801	static void
1802	do_pragma_warning_or_error (cpp_reader *pfile, bool error)
1803	{
1804	const cpp_token *tok = _cpp_lex_token (pfile);
1805	cpp_string str;
1806	if (tok->type != CPP_STRING
1807	|| !cpp_interpret_string_notranslate (pfile, &tok->val.str, 1, &str,
1808	CPP_STRING)
1809	|| str.len == 0)
1810	{
1811	cpp_error (pfile, CPP_DL_ERROR, msgid: "invalid \"#pragma GCC %s\" directive",
1812	error ? "error" : "warning");
1813	return;
1814	}
1815	cpp_error (pfile, error ? CPP_DL_ERROR : CPP_DL_WARNING,
1816	msgid: "%s", str.text);
1817	free (ptr: (void *)str.text);
1818	}
1819
1820	/* Issue a warning diagnostic. */
1821	static void
1822	do_pragma_warning (cpp_reader *pfile)
1823	{
1824	do_pragma_warning_or_error (pfile, error: false);
1825	}
1826
1827	/* Issue an error diagnostic. */
1828	static void
1829	do_pragma_error (cpp_reader *pfile)
1830	{
1831	do_pragma_warning_or_error (pfile, error: true);
1832	}
1833
1834	/* Get a token but skip padding. */
1835	static const cpp_token *
1836	get_token_no_padding (cpp_reader *pfile)
1837	{
1838	for (;;)
1839	{
1840	const cpp_token *result = cpp_get_token (pfile);
1841	if (result->type != CPP_PADDING)
1842	return result;
1843	}
1844	}
1845
1846	/* Check syntax is "(string-literal)". Returns the string on success,
1847	or NULL on failure. */
1848	static const cpp_token *
1849	get__Pragma_string (cpp_reader *pfile)
1850	{
1851	const cpp_token *string;
1852	const cpp_token *paren;
1853
1854	paren = get_token_no_padding (pfile);
1855	if (paren->type == CPP_EOF)
1856	_cpp_backup_tokens (pfile, 1);
1857	if (paren->type != CPP_OPEN_PAREN)
1858	return NULL;
1859
1860	string = get_token_no_padding (pfile);
1861	if (string->type == CPP_EOF)
1862	_cpp_backup_tokens (pfile, 1);
1863	if (string->type != CPP_STRING && string->type != CPP_WSTRING
1864	&& string->type != CPP_STRING32 && string->type != CPP_STRING16
1865	&& string->type != CPP_UTF8STRING)
1866	return NULL;
1867
1868	paren = get_token_no_padding (pfile);
1869	if (paren->type == CPP_EOF)
1870	_cpp_backup_tokens (pfile, 1);
1871	if (paren->type != CPP_CLOSE_PAREN)
1872	return NULL;
1873
1874	return string;
1875	}
1876
1877	/* Destringize IN into a temporary buffer, by removing the first \ of
1878	\" and \\ sequences, and process the result as a #pragma directive. */
1879	static void
1880	destringize_and_run (cpp_reader *pfile, const cpp_string *in,
1881	location_t expansion_loc)
1882	{
1883	const unsigned char *src, *limit;
1884	char *dest, *result;
1885	cpp_context *saved_context;
1886	cpp_token *saved_cur_token;
1887	tokenrun *saved_cur_run;
1888	cpp_token *toks;
1889	int count;
1890	const struct directive *save_directive;
1891
1892	dest = result = (char *) alloca (in->len - 1);
1893	src = in->text + 1 + (in->text[0] == 'L');
1894	limit = in->text + in->len - 1;
1895	while (src < limit)
1896	{
1897	/* We know there is a character following the backslash. */
1898	if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
1899	src++;
1900	*dest++ = *src++;
1901	}
1902	*dest = '\n';
1903
1904	/* Ugh; an awful kludge. We are really not set up to be lexing
1905	tokens when in the middle of a macro expansion. Use a new
1906	context to force cpp_get_token to lex, and so skip_rest_of_line
1907	doesn't go beyond the end of the text. Also, remember the
1908	current lexing position so we can return to it later.
1909
1910	Something like line-at-a-time lexing should remove the need for
1911	this. */
1912	saved_context = pfile->context;
1913	saved_cur_token = pfile->cur_token;
1914	saved_cur_run = pfile->cur_run;
1915
1916	pfile->context = XCNEW (cpp_context);
1917
1918	/* Inline run_directive, since we need to delay the _cpp_pop_buffer
1919	until we've read all of the tokens that we want. */
1920	cpp_push_buffer (pfile, (const uchar *) result, dest - result,
1921	/* from_stage3 */ true);
1922	/* ??? Antique Disgusting Hack. What does this do? */
1923	if (pfile->buffer->prev)
1924	pfile->buffer->file = pfile->buffer->prev->file;
1925
1926	start_directive (pfile);
1927	_cpp_clean_line (pfile);
1928	save_directive = pfile->directive;
1929	pfile->directive = &dtable[T_PRAGMA];
1930	do_pragma (pfile);
1931	if (pfile->directive_result.type == CPP_PRAGMA)
1932	pfile->directive_result.flags |= PRAGMA_OP;
1933	end_directive (pfile, skip_line: 1);
1934	pfile->directive = save_directive;
1935
1936	/* We always insert at least one token, the directive result. It'll
1937	either be a CPP_PADDING or a CPP_PRAGMA. In the later case, we
1938	need to insert *all* of the tokens, including the CPP_PRAGMA_EOL. */
1939
1940	/* If we're not handling the pragma internally, read all of the tokens from
1941	the string buffer now, while the string buffer is still installed. */
1942	/* ??? Note that the token buffer allocated here is leaked. It's not clear
1943	to me what the true lifespan of the tokens are. It would appear that
1944	the lifespan is the entire parse of the main input stream, in which case
1945	this may not be wrong. */
1946	if (pfile->directive_result.type == CPP_PRAGMA)
1947	{
1948	int maxcount;
1949
1950	count = 1;
1951	maxcount = 50;
1952	toks = XNEWVEC (cpp_token, maxcount);
1953	toks[0] = pfile->directive_result;
1954	toks[0].src_loc = expansion_loc;
1955
1956	do
1957	{
1958	if (count == maxcount)
1959	{
1960	maxcount = maxcount * 3 / 2;
1961	toks = XRESIZEVEC (cpp_token, toks, maxcount);
1962	}
1963	toks[count] = *cpp_get_token (pfile);
1964	/* _Pragma is a builtin, so we're not within a macro-map, and so
1965	the token locations are set to bogus ordinary locations
1966	near to, but after that of the "_Pragma".
1967	Paper over this by setting them equal to the location of the
1968	_Pragma itself (PR preprocessor/69126). */
1969	toks[count].src_loc = expansion_loc;
1970	/* Macros have been already expanded by cpp_get_token
1971	if the pragma allowed expansion. */
1972	toks[count++].flags |= NO_EXPAND;
1973	}
1974	while (toks[count-1].type != CPP_PRAGMA_EOL);
1975	}
1976	else
1977	{
1978	count = 1;
1979	toks = &pfile->avoid_paste;
1980
1981	/* If we handled the entire pragma internally, make sure we get the
1982	line number correct for the next token. */
1983	if (pfile->cb.line_change)
1984	pfile->cb.line_change (pfile, pfile->cur_token, false);
1985	}
1986
1987	/* Finish inlining run_directive. */
1988	pfile->buffer->file = NULL;
1989	_cpp_pop_buffer (pfile);
1990
1991	/* Reset the old macro state before ... */
1992	XDELETE (pfile->context);
1993	pfile->context = saved_context;
1994	pfile->cur_token = saved_cur_token;
1995	pfile->cur_run = saved_cur_run;
1996
1997	/* ... inserting the new tokens we collected. */
1998	_cpp_push_token_context (pfile, NULL, toks, count);
1999	}
2000
2001	/* Handle the _Pragma operator. Return 0 on error, 1 if ok. */
2002	int
2003	_cpp_do__Pragma (cpp_reader *pfile, location_t expansion_loc)
2004	{
2005	/* Make sure we don't invalidate the string token, if the closing parenthesis
2006	ended up on a different line. */
2007	++pfile->keep_tokens;
2008	const cpp_token *string = get__Pragma_string (pfile);
2009	--pfile->keep_tokens;
2010
2011	pfile->directive_result.type = CPP_PADDING;
2012
2013	if (string)
2014	{
2015	destringize_and_run (pfile, in: &string->val.str, expansion_loc);
2016	return 1;
2017	}
2018	cpp_error (pfile, CPP_DL_ERROR,
2019	msgid: "_Pragma takes a parenthesized string literal");
2020	return 0;
2021	}
2022
2023	/* Handle #ifdef. */
2024	static void
2025	do_ifdef (cpp_reader *pfile)
2026	{
2027	int skip = 1;
2028
2029	if (! pfile->state.skipping)
2030	{
2031	cpp_hashnode *node = lex_macro_node (pfile, is_def_or_undef: false);
2032
2033	if (node)
2034	{
2035	skip = !_cpp_defined_macro_p (node);
2036	if (!_cpp_maybe_notify_macro_use (pfile, node, loc: pfile->directive_line))
2037	/* It wasn't a macro after all. */
2038	skip = true;
2039	_cpp_mark_macro_used (node);
2040	if (pfile->cb.used)
2041	pfile->cb.used (pfile, pfile->directive_line, node);
2042	check_eol (pfile, expand: false);
2043	}
2044	}
2045
2046	push_conditional (pfile, skip, T_IFDEF, 0);
2047	}
2048
2049	/* Handle #ifndef. */
2050	static void
2051	do_ifndef (cpp_reader *pfile)
2052	{
2053	int skip = 1;
2054	cpp_hashnode *node = 0;
2055
2056	if (! pfile->state.skipping)
2057	{
2058	node = lex_macro_node (pfile, is_def_or_undef: false);
2059
2060	if (node)
2061	{
2062	skip = _cpp_defined_macro_p (node);
2063	if (!_cpp_maybe_notify_macro_use (pfile, node, loc: pfile->directive_line))
2064	/* It wasn't a macro after all. */
2065	skip = false;
2066	_cpp_mark_macro_used (node);
2067	if (pfile->cb.used)
2068	pfile->cb.used (pfile, pfile->directive_line, node);
2069	check_eol (pfile, expand: false);
2070	}
2071	}
2072
2073	push_conditional (pfile, skip, T_IFNDEF, node);
2074	}
2075
2076	/* _cpp_parse_expr puts a macro in a "#if !defined ()" expression in
2077	pfile->mi_ind_cmacro so we can handle multiple-include
2078	optimizations. If macro expansion occurs in the expression, we
2079	cannot treat it as a controlling conditional, since the expansion
2080	could change in the future. That is handled by cpp_get_token. */
2081	static void
2082	do_if (cpp_reader *pfile)
2083	{
2084	int skip = 1;
2085
2086	if (! pfile->state.skipping)
2087	skip = _cpp_parse_expr (pfile, true) == false;
2088
2089	push_conditional (pfile, skip, T_IF, pfile->mi_ind_cmacro);
2090	}
2091
2092	/* Flip skipping state if appropriate and continue without changing
2093	if_stack; this is so that the error message for missing #endif's
2094	etc. will point to the original #if. */
2095	static void
2096	do_else (cpp_reader *pfile)
2097	{
2098	cpp_buffer *buffer = pfile->buffer;
2099	struct if_stack *ifs = buffer->if_stack;
2100
2101	if (ifs == NULL)
2102	cpp_error (pfile, CPP_DL_ERROR, msgid: "#else without #if");
2103	else
2104	{
2105	if (ifs->type == T_ELSE)
2106	{
2107	cpp_error (pfile, CPP_DL_ERROR, msgid: "#else after #else");
2108	cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
2109	msgid: "the conditional began here");
2110	}
2111	ifs->type = T_ELSE;
2112
2113	/* Skip any future (erroneous) #elses or #elifs. */
2114	pfile->state.skipping = ifs->skip_elses;
2115	ifs->skip_elses = true;
2116
2117	/* Invalidate any controlling macro. */
2118	ifs->mi_cmacro = 0;
2119
2120	/* Only check EOL if was not originally skipping. */
2121	if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
2122	check_eol_endif_labels (pfile);
2123	}
2124	}
2125
2126	/* Handle a #elif, #elifdef or #elifndef directive by not changing if_stack
2127	either. See the comment above do_else. */
2128	static void
2129	do_elif (cpp_reader *pfile)
2130	{
2131	cpp_buffer *buffer = pfile->buffer;
2132	struct if_stack *ifs = buffer->if_stack;
2133
2134	if (ifs == NULL)
2135	cpp_error (pfile, CPP_DL_ERROR, msgid: "#%s without #if", pfile->directive->name);
2136	else
2137	{
2138	if (ifs->type == T_ELSE)
2139	{
2140	cpp_error (pfile, CPP_DL_ERROR, msgid: "#%s after #else",
2141	pfile->directive->name);
2142	cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
2143	msgid: "the conditional began here");
2144	}
2145	ifs->type = T_ELIF;
2146
2147	/* See DR#412: "Only the first group whose control condition
2148	evaluates to true (nonzero) is processed; any following groups
2149	are skipped and their controlling directives are processed as
2150	if they were in a group that is skipped." */
2151	if (ifs->skip_elses)
2152	{
2153	/* In older GNU standards, #elifdef/#elifndef is supported
2154	as an extension, but pedwarn if -pedantic if the presence
2155	of the directive would be rejected. */
2156	if (pfile->directive != &dtable[T_ELIF]
2157	&& ! CPP_OPTION (pfile, elifdef)
2158	&& CPP_PEDANTIC (pfile)
2159	&& !pfile->state.skipping)
2160	{
2161	if (CPP_OPTION (pfile, cplusplus))
2162	cpp_error (pfile, CPP_DL_PEDWARN,
2163	msgid: "#%s before C++23 is a GCC extension",
2164	pfile->directive->name);
2165	else
2166	cpp_error (pfile, CPP_DL_PEDWARN,
2167	msgid: "#%s before C23 is a GCC extension",
2168	pfile->directive->name);
2169	}
2170	pfile->state.skipping = 1;
2171	}
2172	else
2173	{
2174	if (pfile->directive == &dtable[T_ELIF])
2175	pfile->state.skipping = !_cpp_parse_expr (pfile, false);
2176	else
2177	{
2178	cpp_hashnode *node = lex_macro_node (pfile, is_def_or_undef: false);
2179
2180	if (node)
2181	{
2182	bool macro_defined = _cpp_defined_macro_p (node);
2183	if (!_cpp_maybe_notify_macro_use (pfile, node,
2184	loc: pfile->directive_line))
2185	/* It wasn't a macro after all. */
2186	macro_defined = false;
2187	bool skip = (pfile->directive == &dtable[T_ELIFDEF]
2188	? !macro_defined
2189	: macro_defined);
2190	if (pfile->cb.used)
2191	pfile->cb.used (pfile, pfile->directive_line, node);
2192	check_eol (pfile, expand: false);
2193	/* In older GNU standards, #elifdef/#elifndef is supported
2194	as an extension, but pedwarn if -pedantic if the presence
2195	of the directive would change behavior. */
2196	if (! CPP_OPTION (pfile, elifdef)
2197	&& CPP_PEDANTIC (pfile)
2198	&& pfile->state.skipping != skip)
2199	{
2200	if (CPP_OPTION (pfile, cplusplus))
2201	cpp_error (pfile, CPP_DL_PEDWARN,
2202	msgid: "#%s before C++23 is a GCC extension",
2203	pfile->directive->name);
2204	else
2205	cpp_error (pfile, CPP_DL_PEDWARN,
2206	msgid: "#%s before C23 is a GCC extension",
2207	pfile->directive->name);
2208	}
2209	pfile->state.skipping = skip;
2210	}
2211	}
2212	ifs->skip_elses = !pfile->state.skipping;
2213	}
2214
2215	/* Invalidate any controlling macro. */
2216	ifs->mi_cmacro = 0;
2217	}
2218	}
2219
2220	/* Handle a #elifdef directive. */
2221	static void
2222	do_elifdef (cpp_reader *pfile)
2223	{
2224	do_elif (pfile);
2225	}
2226
2227	/* Handle a #elifndef directive. */
2228	static void
2229	do_elifndef (cpp_reader *pfile)
2230	{
2231	do_elif (pfile);
2232	}
2233
2234	/* #endif pops the if stack and resets pfile->state.skipping. */
2235	static void
2236	do_endif (cpp_reader *pfile)
2237	{
2238	cpp_buffer *buffer = pfile->buffer;
2239	struct if_stack *ifs = buffer->if_stack;
2240
2241	if (ifs == NULL)
2242	cpp_error (pfile, CPP_DL_ERROR, msgid: "#endif without #if");
2243	else
2244	{
2245	/* Only check EOL if was not originally skipping. */
2246	if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
2247	check_eol_endif_labels (pfile);
2248
2249	/* If potential control macro, we go back outside again. */
2250	if (ifs->next == 0 && ifs->mi_cmacro)
2251	{
2252	pfile->mi_valid = true;
2253	pfile->mi_cmacro = ifs->mi_cmacro;
2254	}
2255
2256	buffer->if_stack = ifs->next;
2257	pfile->state.skipping = ifs->was_skipping;
2258	obstack_free (&pfile->buffer_ob, ifs);
2259	}
2260	}
2261
2262	/* Push an if_stack entry for a preprocessor conditional, and set
2263	pfile->state.skipping to SKIP. If TYPE indicates the conditional
2264	is #if or #ifndef, CMACRO is a potentially controlling macro, and
2265	we need to check here that we are at the top of the file. */
2266	static void
2267	push_conditional (cpp_reader *pfile, int skip, int type,
2268	const cpp_hashnode *cmacro)
2269	{
2270	struct if_stack *ifs;
2271	cpp_buffer *buffer = pfile->buffer;
2272
2273	ifs = XOBNEW (&pfile->buffer_ob, struct if_stack);
2274	ifs->line = pfile->directive_line;
2275	ifs->next = buffer->if_stack;
2276	ifs->skip_elses = pfile->state.skipping || !skip;
2277	ifs->was_skipping = pfile->state.skipping;
2278	ifs->type = type;
2279	/* This condition is effectively a test for top-of-file. */
2280	if (pfile->mi_valid && pfile->mi_cmacro == 0)
2281	ifs->mi_cmacro = cmacro;
2282	else
2283	ifs->mi_cmacro = 0;
2284
2285	pfile->state.skipping = skip;
2286	buffer->if_stack = ifs;
2287	}
2288
2289	/* Read the tokens of the answer into the macro pool, in a directive
2290	of type TYPE. Only commit the memory if we intend it as permanent
2291	storage, i.e. the #assert case. Returns 0 on success, and sets
2292	ANSWERP to point to the answer. PRED_LOC is the location of the
2293	predicate. */
2294	static bool
2295	parse_answer (cpp_reader *pfile, int type, location_t pred_loc,
2296	cpp_macro **answer_ptr)
2297	{
2298	/* In a conditional, it is legal to not have an open paren. We
2299	should save the following token in this case. */
2300	const cpp_token *paren = cpp_get_token (pfile);
2301
2302	/* If not a paren, see if we're OK. */
2303	if (paren->type != CPP_OPEN_PAREN)
2304	{
2305	/* In a conditional no answer is a test for any answer. It
2306	could be followed by any token. */
2307	if (type == T_IF)
2308	{
2309	_cpp_backup_tokens (pfile, 1);
2310	return true;
2311	}
2312
2313	/* #unassert with no answer is valid - it removes all answers. */
2314	if (type == T_UNASSERT && paren->type == CPP_EOF)
2315	return true;
2316
2317	cpp_error_with_line (pfile, CPP_DL_ERROR, pred_loc, 0,
2318	msgid: "missing '(' after predicate");
2319	return false;
2320	}
2321
2322	cpp_macro *answer = _cpp_new_macro (pfile, cmk_assert,
2323	_cpp_reserve_room (pfile, have: 0,
2324	extra: sizeof (cpp_macro)));
2325	answer->parm.next = NULL;
2326	unsigned count = 0;
2327	for (;;)
2328	{
2329	const cpp_token *token = cpp_get_token (pfile);
2330
2331	if (token->type == CPP_CLOSE_PAREN)
2332	break;
2333
2334	if (token->type == CPP_EOF)
2335	{
2336	cpp_error (pfile, CPP_DL_ERROR, msgid: "missing ')' to complete answer");
2337	return false;
2338	}
2339
2340	answer = (cpp_macro *)_cpp_reserve_room
2341	(pfile, have: sizeof (cpp_macro) + count * sizeof (cpp_token),
2342	extra: sizeof (cpp_token));
2343	answer->exp.tokens[count++] = *token;
2344	}
2345
2346	if (!count)
2347	{
2348	cpp_error (pfile, CPP_DL_ERROR, msgid: "predicate's answer is empty");
2349	return false;
2350	}
2351
2352	/* Drop whitespace at start, for answer equivalence purposes. */
2353	answer->exp.tokens[0].flags &= ~PREV_WHITE;
2354
2355	answer->count = count;
2356	*answer_ptr = answer;
2357
2358	return true;
2359	}
2360
2361	/* Parses an assertion directive of type TYPE, returning a pointer to
2362	the hash node of the predicate, or 0 on error. The node is
2363	guaranteed to be disjoint from the macro namespace, so can only
2364	have type 'NT_VOID'. If an answer was supplied, it is placed in
2365	*ANSWER_PTR, which is otherwise set to 0. */
2366	static cpp_hashnode *
2367	parse_assertion (cpp_reader *pfile, int type, cpp_macro **answer_ptr)
2368	{
2369	cpp_hashnode *result = 0;
2370
2371	/* We don't expand predicates or answers. */
2372	pfile->state.prevent_expansion++;
2373
2374	*answer_ptr = NULL;
2375
2376	const cpp_token *predicate = cpp_get_token (pfile);
2377	if (predicate->type == CPP_EOF)
2378	cpp_error (pfile, CPP_DL_ERROR, msgid: "assertion without predicate");
2379	else if (predicate->type != CPP_NAME)
2380	cpp_error_with_line (pfile, CPP_DL_ERROR, predicate->src_loc, 0,
2381	msgid: "predicate must be an identifier");
2382	else if (parse_answer (pfile, type, pred_loc: predicate->src_loc, answer_ptr))
2383	{
2384	unsigned int len = NODE_LEN (predicate->val.node.node);
2385	unsigned char *sym = (unsigned char *) alloca (len + 1);
2386
2387	/* Prefix '#' to get it out of macro namespace. */
2388	sym[0] = '#';
2389	memcpy (dest: sym + 1, NODE_NAME (predicate->val.node.node), n: len);
2390	result = cpp_lookup (pfile, sym, len + 1);
2391	}
2392
2393	pfile->state.prevent_expansion--;
2394
2395	return result;
2396	}
2397
2398	/* Returns a pointer to the pointer to CANDIDATE in the answer chain,
2399	or a pointer to NULL if the answer is not in the chain. */
2400	static cpp_macro **
2401	find_answer (cpp_hashnode *node, const cpp_macro *candidate)
2402	{
2403	unsigned int i;
2404	cpp_macro **result = NULL;
2405
2406	for (result = &node->value.answers; *result; result = &(*result)->parm.next)
2407	{
2408	cpp_macro *answer = *result;
2409
2410	if (answer->count == candidate->count)
2411	{
2412	for (i = 0; i < answer->count; i++)
2413	if (!_cpp_equiv_tokens (&answer->exp.tokens[i],
2414	&candidate->exp.tokens[i]))
2415	break;
2416
2417	if (i == answer->count)
2418	break;
2419	}
2420	}
2421
2422	return result;
2423	}
2424
2425	/* Test an assertion within a preprocessor conditional. Returns
2426	nonzero on failure, zero on success. On success, the result of
2427	the test is written into VALUE, otherwise the value 0. */
2428	int
2429	_cpp_test_assertion (cpp_reader *pfile, unsigned int *value)
2430	{
2431	cpp_macro *answer;
2432	cpp_hashnode *node = parse_assertion (pfile, type: T_IF, answer_ptr: &answer);
2433
2434	/* For recovery, an erroneous assertion expression is handled as a
2435	failing assertion. */
2436	*value = 0;
2437
2438	if (node)
2439	{
2440	if (node->value.answers)
2441	*value = !answer || *find_answer (node, candidate: answer);
2442	}
2443	else if (pfile->cur_token[-1].type == CPP_EOF)
2444	_cpp_backup_tokens (pfile, 1);
2445
2446	/* We don't commit the memory for the answer - it's temporary only. */
2447	return node == 0;
2448	}
2449
2450	/* Handle #assert. */
2451	static void
2452	do_assert (cpp_reader *pfile)
2453	{
2454	cpp_macro *answer;
2455	cpp_hashnode *node = parse_assertion (pfile, type: T_ASSERT, answer_ptr: &answer);
2456
2457	if (node)
2458	{
2459	/* Place the new answer in the answer list. First check there
2460	is not a duplicate. */
2461	if (*find_answer (node, candidate: answer))
2462	{
2463	cpp_error (pfile, CPP_DL_WARNING, msgid: "\"%s\" re-asserted",
2464	NODE_NAME (node) + 1);
2465	return;
2466	}
2467
2468	/* Commit or allocate storage for the answer. */
2469	answer = (cpp_macro *)_cpp_commit_buff
2470	(pfile, size: sizeof (cpp_macro) - sizeof (cpp_token)
2471	+ sizeof (cpp_token) * answer->count);
2472
2473	/* Chain into the list. */
2474	answer->parm.next = node->value.answers;
2475	node->value.answers = answer;
2476
2477	check_eol (pfile, expand: false);
2478	}
2479	}
2480
2481	/* Handle #unassert. */
2482	static void
2483	do_unassert (cpp_reader *pfile)
2484	{
2485	cpp_macro *answer;
2486	cpp_hashnode *node = parse_assertion (pfile, type: T_UNASSERT, answer_ptr: &answer);
2487
2488	/* It isn't an error to #unassert something that isn't asserted. */
2489	if (node)
2490	{
2491	if (answer)
2492	{
2493	cpp_macro **p = find_answer (node, candidate: answer);
2494
2495	/* Remove the assert from the list. */
2496	if (cpp_macro *temp = *p)
2497	*p = temp->parm.next;
2498
2499	check_eol (pfile, expand: false);
2500	}
2501	else
2502	_cpp_free_definition (node);
2503	}
2504
2505	/* We don't commit the memory for the answer - it's temporary only. */
2506	}
2507
2508	/* These are for -D, -U, -A. */
2509
2510	/* Process the string STR as if it appeared as the body of a #define.
2511	If STR is just an identifier, define it with value 1.
2512	If STR has anything after the identifier, then it should
2513	be identifier=definition. */
2514	void
2515	cpp_define (cpp_reader *pfile, const char *str)
2516	{
2517	char *buf;
2518	const char *p;
2519	size_t count;
2520
2521	/* Copy the entire option so we can modify it.
2522	Change the first "=" in the string to a space. If there is none,
2523	tack " 1" on the end. */
2524
2525	count = strlen (s: str);
2526	buf = (char *) alloca (count + 3);
2527	memcpy (dest: buf, src: str, n: count);
2528
2529	p = strchr (s: str, c: '=');
2530	if (p)
2531	buf[p - str] = ' ';
2532	else
2533	{
2534	buf[count++] = ' ';
2535	buf[count++] = '1';
2536	}
2537	buf[count] = '\n';
2538
2539	run_directive (pfile, dir_no: T_DEFINE, buf, count);
2540	}
2541
2542	/* Like cpp_define, but does not warn about unused macro. */
2543	void
2544	cpp_define_unused (cpp_reader *pfile, const char *str)
2545	{
2546	unsigned char warn_unused_macros = CPP_OPTION (pfile, warn_unused_macros);
2547	CPP_OPTION (pfile, warn_unused_macros) = 0;
2548	cpp_define (pfile, str);
2549	CPP_OPTION (pfile, warn_unused_macros) = warn_unused_macros;
2550	}
2551
2552	/* Use to build macros to be run through cpp_define() as
2553	described above.
2554	Example: cpp_define_formatted (pfile, "MACRO=%d", value); */
2555
2556	void
2557	cpp_define_formatted (cpp_reader *pfile, const char *fmt, ...)
2558	{
2559	char *ptr;
2560
2561	va_list ap;
2562	va_start (ap, fmt);
2563	ptr = xvasprintf (fmt, ap);
2564	va_end (ap);
2565
2566	cpp_define (pfile, str: ptr);
2567	free (ptr: ptr);
2568	}
2569
2570	/* Like cpp_define_formatted, but does not warn about unused macro. */
2571	void
2572	cpp_define_formatted_unused (cpp_reader *pfile, const char *fmt, ...)
2573	{
2574	char *ptr;
2575
2576	va_list ap;
2577	va_start (ap, fmt);
2578	ptr = xvasprintf (fmt, ap);
2579	va_end (ap);
2580
2581	cpp_define_unused (pfile, str: ptr);
2582	free (ptr: ptr);
2583	}
2584
2585	/* Slight variant of the above for use by initialize_builtins. */
2586	void
2587	_cpp_define_builtin (cpp_reader *pfile, const char *str)
2588	{
2589	size_t len = strlen (s: str);
2590	char *buf = (char *) alloca (len + 1);
2591	memcpy (dest: buf, src: str, n: len);
2592	buf[len] = '\n';
2593	run_directive (pfile, dir_no: T_DEFINE, buf, count: len);
2594	}
2595
2596	/* Process MACRO as if it appeared as the body of an #undef. */
2597	void
2598	cpp_undef (cpp_reader *pfile, const char *macro)
2599	{
2600	size_t len = strlen (s: macro);
2601	char *buf = (char *) alloca (len + 1);
2602	memcpy (dest: buf, src: macro, n: len);
2603	buf[len] = '\n';
2604	run_directive (pfile, dir_no: T_UNDEF, buf, count: len);
2605	}
2606
2607	/* Replace a previous definition DEF of the macro STR. If DEF is NULL,
2608	or first element is zero, then the macro should be undefined. */
2609	static void
2610	cpp_pop_definition (cpp_reader *pfile, struct def_pragma_macro *c)
2611	{
2612	cpp_hashnode *node = _cpp_lex_identifier (pfile, c->name);
2613	if (node == NULL)
2614	return;
2615
2616	if (pfile->cb.before_define)
2617	pfile->cb.before_define (pfile);
2618
2619	if (cpp_macro_p (node))
2620	{
2621	if (pfile->cb.undef)
2622	pfile->cb.undef (pfile, pfile->directive_line, node);
2623	if (CPP_OPTION (pfile, warn_unused_macros))
2624	_cpp_warn_if_unused_macro (pfile, node, NULL);
2625	_cpp_free_definition (node);
2626	}
2627
2628	if (c->is_undef)
2629	return;
2630	if (c->is_builtin)
2631	{
2632	_cpp_restore_special_builtin (pfile, c);
2633	return;
2634	}
2635
2636	{
2637	size_t namelen;
2638	const uchar *dn;
2639	cpp_hashnode *h = NULL;
2640	cpp_buffer *nbuf;
2641
2642	namelen = ustrcspn (s1: c->definition, s2: "( \n");
2643	h = cpp_lookup (pfile, c->definition, namelen);
2644	dn = c->definition + namelen;
2645
2646	nbuf = cpp_push_buffer (pfile, dn, ustrchr (s1: dn, c: '\n') - dn, true);
2647	if (nbuf != NULL)
2648	{
2649	_cpp_clean_line (pfile);
2650	nbuf->sysp = 1;
2651	if (!_cpp_create_definition (pfile, h, 0))
2652	abort ();
2653	_cpp_pop_buffer (pfile);
2654	}
2655	else
2656	abort ();
2657	h->value.macro->line = c->line;
2658	h->value.macro->syshdr = c->syshdr;
2659	h->value.macro->used = c->used;
2660	}
2661	}
2662
2663	/* Process the string STR as if it appeared as the body of a #assert. */
2664	void
2665	cpp_assert (cpp_reader *pfile, const char *str)
2666	{
2667	handle_assertion (pfile, str, T_ASSERT);
2668	}
2669
2670	/* Process STR as if it appeared as the body of an #unassert. */
2671	void
2672	cpp_unassert (cpp_reader *pfile, const char *str)
2673	{
2674	handle_assertion (pfile, str, T_UNASSERT);
2675	}
2676
2677	/* Common code for cpp_assert (-A) and cpp_unassert (-A-). */
2678	static void
2679	handle_assertion (cpp_reader *pfile, const char *str, int type)
2680	{
2681	size_t count = strlen (s: str);
2682	const char *p = strchr (s: str, c: '=');
2683
2684	/* Copy the entire option so we can modify it. Change the first
2685	"=" in the string to a '(', and tack a ')' on the end. */
2686	char *buf = (char *) alloca (count + 2);
2687
2688	memcpy (dest: buf, src: str, n: count);
2689	if (p)
2690	{
2691	buf[p - str] = '(';
2692	buf[count++] = ')';
2693	}
2694	buf[count] = '\n';
2695	str = buf;
2696
2697	run_directive (pfile, dir_no: type, buf: str, count);
2698	}
2699
2700	/* The options structure. */
2701	cpp_options *
2702	cpp_get_options (cpp_reader *pfile)
2703	{
2704	return &pfile->opts;
2705	}
2706
2707	/* The callbacks structure. */
2708	cpp_callbacks *
2709	cpp_get_callbacks (cpp_reader *pfile)
2710	{
2711	return &pfile->cb;
2712	}
2713
2714	/* Copy the given callbacks structure to our own. */
2715	void
2716	cpp_set_callbacks (cpp_reader *pfile, cpp_callbacks *cb)
2717	{
2718	pfile->cb = *cb;
2719	}
2720
2721	/* The narrow character set identifier. */
2722	const char *
2723	cpp_get_narrow_charset_name (cpp_reader *pfile)
2724	{
2725	return pfile->narrow_cset_desc.to;
2726	}
2727
2728	/* The wide character set identifier. */
2729	const char *
2730	cpp_get_wide_charset_name (cpp_reader *pfile)
2731	{
2732	return pfile->wide_cset_desc.to;
2733	}
2734
2735	/* The dependencies structure. (Creates one if it hasn't already been.) */
2736	class mkdeps *
2737	cpp_get_deps (cpp_reader *pfile)
2738	{
2739	if (!pfile->deps && CPP_OPTION (pfile, deps.style) != DEPS_NONE)
2740	pfile->deps = deps_init ();
2741	return pfile->deps;
2742	}
2743
2744	/* Push a new buffer on the buffer stack. Returns the new buffer; it
2745	doesn't fail. It does not generate a file change call back; that
2746	is the responsibility of the caller. */
2747	cpp_buffer *
2748	cpp_push_buffer (cpp_reader *pfile, const uchar *buffer, size_t len,
2749	int from_stage3)
2750	{
2751	cpp_buffer *new_buffer = XOBNEW (&pfile->buffer_ob, cpp_buffer);
2752
2753	/* Clears, amongst other things, if_stack and mi_cmacro. */
2754	memset (s: new_buffer, c: 0, n: sizeof (cpp_buffer));
2755
2756	new_buffer->next_line = new_buffer->buf = buffer;
2757	new_buffer->rlimit = buffer + len;
2758	new_buffer->from_stage3 = from_stage3;
2759	new_buffer->prev = pfile->buffer;
2760	new_buffer->need_line = true;
2761
2762	pfile->buffer = new_buffer;
2763
2764	return new_buffer;
2765	}
2766
2767	/* Pops a single buffer, with a file change call-back if appropriate.
2768	Then pushes the next -include file, if any remain. */
2769	void
2770	_cpp_pop_buffer (cpp_reader *pfile)
2771	{
2772	cpp_buffer *buffer = pfile->buffer;
2773	struct _cpp_file *inc = buffer->file;
2774	struct if_stack *ifs;
2775	const unsigned char *to_free;
2776
2777	/* Walk back up the conditional stack till we reach its level at
2778	entry to this file, issuing error messages. */
2779	for (ifs = buffer->if_stack; ifs; ifs = ifs->next)
2780	cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
2781	msgid: "unterminated #%s", dtable[ifs->type].name);
2782
2783	/* In case of a missing #endif. */
2784	pfile->state.skipping = 0;
2785
2786	/* _cpp_do_file_change expects pfile->buffer to be the new one. */
2787	pfile->buffer = buffer->prev;
2788
2789	to_free = buffer->to_free;
2790	free (ptr: buffer->notes);
2791
2792	/* Free the buffer object now; we may want to push a new buffer
2793	in _cpp_push_next_include_file. */
2794	obstack_free (&pfile->buffer_ob, buffer);
2795
2796	if (inc)
2797	{
2798	_cpp_pop_file_buffer (pfile, inc, to_free);
2799
2800	_cpp_do_file_change (pfile, reason: LC_LEAVE, to_file: 0, to_line: 0, sysp: 0);
2801	}
2802	else if (to_free)
2803	free (ptr: (void *)to_free);
2804	}
2805
2806	/* Enter all recognized directives in the hash table. */
2807	void
2808	_cpp_init_directives (cpp_reader *pfile)
2809	{
2810	for (int i = 0; i < N_DIRECTIVES; i++)
2811	{
2812	cpp_hashnode *node = cpp_lookup (pfile, dtable[i].name, dtable[i].length);
2813	node->is_directive = 1;
2814	node->directive_index = i;
2815	}
2816	}
2817
2818	/* Extract header file from a bracket include. Parsing starts after '<'.
2819	The string is malloced and must be freed by the caller. */
2820	char *
2821	_cpp_bracket_include(cpp_reader *pfile)
2822	{
2823	return glue_header_name (pfile);
2824	}
2825
2826