Daily bump.
[official-gcc.git] / libcpp / traditional.c
blob216906f9c0179f5ff5847de259e9f28285abe5cb
1 /* CPP Library - traditional lexical analysis and macro expansion.
2 Copyright (C) 2002-2013 Free Software Foundation, Inc.
3 Contributed by Neil Booth, May 2002
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 3, or (at your option) any
8 later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; see the file COPYING3. If not see
17 <http://www.gnu.org/licenses/>. */
19 #include "config.h"
20 #include "system.h"
21 #include "cpplib.h"
22 #include "internal.h"
24 /* The replacement text of a function-like macro is stored as a
25 contiguous sequence of aligned blocks, each representing the text
26 between subsequent parameters.
28 Each block comprises the text between its surrounding parameters,
29 the length of that text, and the one-based index of the following
30 parameter. The final block in the replacement text is easily
31 recognizable as it has an argument index of zero. */
33 struct block
35 unsigned int text_len;
36 unsigned short arg_index;
37 uchar text[1];
40 #define BLOCK_HEADER_LEN offsetof (struct block, text)
41 #define BLOCK_LEN(TEXT_LEN) CPP_ALIGN (BLOCK_HEADER_LEN + (TEXT_LEN))
43 /* Structure holding information about a function-like macro
44 invocation. */
45 struct fun_macro
47 /* Memory buffer holding the trad_arg array. */
48 _cpp_buff *buff;
50 /* An array of size the number of macro parameters + 1, containing
51 the offsets of the start of each macro argument in the output
52 buffer. The argument continues until the character before the
53 start of the next one. */
54 size_t *args;
56 /* The hashnode of the macro. */
57 cpp_hashnode *node;
59 /* The offset of the macro name in the output buffer. */
60 size_t offset;
62 /* The line the macro name appeared on. */
63 source_location line;
65 /* Zero-based index of argument being currently lexed. */
66 unsigned int argc;
69 /* Lexing state. It is mostly used to prevent macro expansion. */
70 enum ls {ls_none = 0, /* Normal state. */
71 ls_fun_open, /* When looking for '('. */
72 ls_fun_close, /* When looking for ')'. */
73 ls_defined, /* After defined. */
74 ls_defined_close, /* Looking for ')' of defined(). */
75 ls_hash, /* After # in preprocessor conditional. */
76 ls_predicate, /* After the predicate, maybe paren? */
77 ls_answer}; /* In answer to predicate. */
79 /* Lexing TODO: Maybe handle space in escaped newlines. Stop lex.c
80 from recognizing comments and directives during its lexing pass. */
82 static const uchar *skip_whitespace (cpp_reader *, const uchar *, int);
83 static cpp_hashnode *lex_identifier (cpp_reader *, const uchar *);
84 static const uchar *copy_comment (cpp_reader *, const uchar *, int);
85 static void check_output_buffer (cpp_reader *, size_t);
86 static void push_replacement_text (cpp_reader *, cpp_hashnode *);
87 static bool scan_parameters (cpp_reader *, cpp_macro *);
88 static bool recursive_macro (cpp_reader *, cpp_hashnode *);
89 static void save_replacement_text (cpp_reader *, cpp_macro *, unsigned int);
90 static void maybe_start_funlike (cpp_reader *, cpp_hashnode *, const uchar *,
91 struct fun_macro *);
92 static void save_argument (struct fun_macro *, size_t);
93 static void replace_args_and_push (cpp_reader *, struct fun_macro *);
94 static size_t canonicalize_text (uchar *, const uchar *, size_t, uchar *);
96 /* Ensures we have N bytes' space in the output buffer, and
97 reallocates it if not. */
98 static void
99 check_output_buffer (cpp_reader *pfile, size_t n)
101 /* We might need two bytes to terminate an unterminated comment, and
102 one more to terminate the line with a NUL. */
103 n += 2 + 1;
105 if (n > (size_t) (pfile->out.limit - pfile->out.cur))
107 size_t size = pfile->out.cur - pfile->out.base;
108 size_t new_size = (size + n) * 3 / 2;
110 pfile->out.base = XRESIZEVEC (unsigned char, pfile->out.base, new_size);
111 pfile->out.limit = pfile->out.base + new_size;
112 pfile->out.cur = pfile->out.base + size;
116 /* Skip a C-style block comment in a macro as a result of -CC.
117 Buffer->cur points to the initial asterisk of the comment. */
118 static void
119 skip_macro_block_comment (cpp_reader *pfile)
121 const uchar *cur = pfile->buffer->cur;
123 cur++;
124 if (*cur == '/')
125 cur++;
127 /* People like decorating comments with '*', so check for '/'
128 instead for efficiency. */
129 while(! (*cur++ == '/' && cur[-2] == '*') )
132 pfile->buffer->cur = cur;
135 /* CUR points to the asterisk introducing a comment in the current
136 context. IN_DEFINE is true if we are in the replacement text of a
137 macro.
139 The asterisk and following comment is copied to the buffer pointed
140 to by pfile->out.cur, which must be of sufficient size.
141 Unterminated comments are diagnosed, and correctly terminated in
142 the output. pfile->out.cur is updated depending upon IN_DEFINE,
143 -C, -CC and pfile->state.in_directive.
145 Returns a pointer to the first character after the comment in the
146 input buffer. */
147 static const uchar *
148 copy_comment (cpp_reader *pfile, const uchar *cur, int in_define)
150 bool unterminated, copy = false;
151 source_location src_loc = pfile->line_table->highest_line;
152 cpp_buffer *buffer = pfile->buffer;
154 buffer->cur = cur;
155 if (pfile->context->prev)
156 unterminated = false, skip_macro_block_comment (pfile);
157 else
158 unterminated = _cpp_skip_block_comment (pfile);
160 if (unterminated)
161 cpp_error_with_line (pfile, CPP_DL_ERROR, src_loc, 0,
162 "unterminated comment");
164 /* Comments in directives become spaces so that tokens are properly
165 separated when the ISO preprocessor re-lexes the line. The
166 exception is #define. */
167 if (pfile->state.in_directive)
169 if (in_define)
171 if (CPP_OPTION (pfile, discard_comments_in_macro_exp))
172 pfile->out.cur--;
173 else
174 copy = true;
176 else
177 pfile->out.cur[-1] = ' ';
179 else if (CPP_OPTION (pfile, discard_comments))
180 pfile->out.cur--;
181 else
182 copy = true;
184 if (copy)
186 size_t len = (size_t) (buffer->cur - cur);
187 memcpy (pfile->out.cur, cur, len);
188 pfile->out.cur += len;
189 if (unterminated)
191 *pfile->out.cur++ = '*';
192 *pfile->out.cur++ = '/';
196 return buffer->cur;
199 /* CUR points to any character in the input buffer. Skips over all
200 contiguous horizontal white space and NULs, including comments if
201 SKIP_COMMENTS, until reaching the first non-horizontal-whitespace
202 character or the end of the current context. Escaped newlines are
203 removed.
205 The whitespace is copied verbatim to the output buffer, except that
206 comments are handled as described in copy_comment().
207 pfile->out.cur is updated.
209 Returns a pointer to the first character after the whitespace in
210 the input buffer. */
211 static const uchar *
212 skip_whitespace (cpp_reader *pfile, const uchar *cur, int skip_comments)
214 uchar *out = pfile->out.cur;
216 for (;;)
218 unsigned int c = *cur++;
219 *out++ = c;
221 if (is_nvspace (c))
222 continue;
224 if (c == '/' && *cur == '*' && skip_comments)
226 pfile->out.cur = out;
227 cur = copy_comment (pfile, cur, false /* in_define */);
228 out = pfile->out.cur;
229 continue;
232 out--;
233 break;
236 pfile->out.cur = out;
237 return cur - 1;
240 /* Lexes and outputs an identifier starting at CUR, which is assumed
241 to point to a valid first character of an identifier. Returns
242 the hashnode, and updates out.cur. */
243 static cpp_hashnode *
244 lex_identifier (cpp_reader *pfile, const uchar *cur)
246 size_t len;
247 uchar *out = pfile->out.cur;
248 cpp_hashnode *result;
251 *out++ = *cur++;
252 while (is_numchar (*cur));
254 CUR (pfile->context) = cur;
255 len = out - pfile->out.cur;
256 result = CPP_HASHNODE (ht_lookup (pfile->hash_table, pfile->out.cur,
257 len, HT_ALLOC));
258 pfile->out.cur = out;
259 return result;
262 /* Overlays the true file buffer temporarily with text of length LEN
263 starting at START. The true buffer is restored upon calling
264 restore_buff(). */
265 void
266 _cpp_overlay_buffer (cpp_reader *pfile, const uchar *start, size_t len)
268 cpp_buffer *buffer = pfile->buffer;
270 pfile->overlaid_buffer = buffer;
271 pfile->saved_cur = buffer->cur;
272 pfile->saved_rlimit = buffer->rlimit;
273 pfile->saved_line_base = buffer->next_line;
274 buffer->need_line = false;
276 buffer->cur = start;
277 buffer->line_base = start;
278 buffer->rlimit = start + len;
281 /* Restores a buffer overlaid by _cpp_overlay_buffer(). */
282 void
283 _cpp_remove_overlay (cpp_reader *pfile)
285 cpp_buffer *buffer = pfile->overlaid_buffer;
287 buffer->cur = pfile->saved_cur;
288 buffer->rlimit = pfile->saved_rlimit;
289 buffer->line_base = pfile->saved_line_base;
290 buffer->need_line = true;
292 pfile->overlaid_buffer = NULL;
295 /* Reads a logical line into the output buffer. Returns TRUE if there
296 is more text left in the buffer. */
297 bool
298 _cpp_read_logical_line_trad (cpp_reader *pfile)
302 if (pfile->buffer->need_line && !_cpp_get_fresh_line (pfile))
303 return false;
305 while (!_cpp_scan_out_logical_line (pfile, NULL) || pfile->state.skipping);
307 return pfile->buffer != NULL;
310 /* Set up state for finding the opening '(' of a function-like
311 macro. */
312 static void
313 maybe_start_funlike (cpp_reader *pfile, cpp_hashnode *node, const uchar *start, struct fun_macro *macro)
315 unsigned int n = node->value.macro->paramc + 1;
317 if (macro->buff)
318 _cpp_release_buff (pfile, macro->buff);
319 macro->buff = _cpp_get_buff (pfile, n * sizeof (size_t));
320 macro->args = (size_t *) BUFF_FRONT (macro->buff);
321 macro->node = node;
322 macro->offset = start - pfile->out.base;
323 macro->argc = 0;
326 /* Save the OFFSET of the start of the next argument to MACRO. */
327 static void
328 save_argument (struct fun_macro *macro, size_t offset)
330 macro->argc++;
331 if (macro->argc <= macro->node->value.macro->paramc)
332 macro->args[macro->argc] = offset;
335 /* Copies the next logical line in the current buffer (starting at
336 buffer->cur) to the output buffer. The output is guaranteed to
337 terminate with a NUL character. buffer->cur is updated.
339 If MACRO is non-NULL, then we are scanning the replacement list of
340 MACRO, and we call save_replacement_text() every time we meet an
341 argument. */
342 bool
343 _cpp_scan_out_logical_line (cpp_reader *pfile, cpp_macro *macro)
345 bool result = true;
346 cpp_context *context;
347 const uchar *cur;
348 uchar *out;
349 struct fun_macro fmacro;
350 unsigned int c, paren_depth = 0, quote;
351 enum ls lex_state = ls_none;
352 bool header_ok;
353 const uchar *start_of_input_line;
355 fmacro.buff = NULL;
356 fmacro.args = NULL;
357 fmacro.node = NULL;
358 fmacro.offset = 0;
359 fmacro.line = 0;
360 fmacro.argc = 0;
362 quote = 0;
363 header_ok = pfile->state.angled_headers;
364 CUR (pfile->context) = pfile->buffer->cur;
365 RLIMIT (pfile->context) = pfile->buffer->rlimit;
366 pfile->out.cur = pfile->out.base;
367 pfile->out.first_line = pfile->line_table->highest_line;
368 /* start_of_input_line is needed to make sure that directives really,
369 really start at the first character of the line. */
370 start_of_input_line = pfile->buffer->cur;
371 new_context:
372 context = pfile->context;
373 cur = CUR (context);
374 check_output_buffer (pfile, RLIMIT (context) - cur);
375 out = pfile->out.cur;
377 for (;;)
379 if (!context->prev
380 && cur >= pfile->buffer->notes[pfile->buffer->cur_note].pos)
382 pfile->buffer->cur = cur;
383 _cpp_process_line_notes (pfile, false);
385 c = *cur++;
386 *out++ = c;
388 /* Whitespace should "continue" out of the switch,
389 non-whitespace should "break" out of it. */
390 switch (c)
392 case ' ':
393 case '\t':
394 case '\f':
395 case '\v':
396 case '\0':
397 continue;
399 case '\n':
400 /* If this is a macro's expansion, pop it. */
401 if (context->prev)
403 pfile->out.cur = out - 1;
404 _cpp_pop_context (pfile);
405 goto new_context;
408 /* Omit the newline from the output buffer. */
409 pfile->out.cur = out - 1;
410 pfile->buffer->cur = cur;
411 pfile->buffer->need_line = true;
412 CPP_INCREMENT_LINE (pfile, 0);
414 if ((lex_state == ls_fun_open || lex_state == ls_fun_close)
415 && !pfile->state.in_directive
416 && _cpp_get_fresh_line (pfile))
418 /* Newlines in arguments become a space, but we don't
419 clear any in-progress quote. */
420 if (lex_state == ls_fun_close)
421 out[-1] = ' ';
422 cur = pfile->buffer->cur;
423 continue;
425 goto done;
427 case '<':
428 if (header_ok)
429 quote = '>';
430 break;
431 case '>':
432 if (c == quote)
433 quote = 0;
434 break;
436 case '"':
437 case '\'':
438 if (c == quote)
439 quote = 0;
440 else if (!quote)
441 quote = c;
442 break;
444 case '\\':
445 /* Skip escaped quotes here, it's easier than above. */
446 if (*cur == '\\' || *cur == '"' || *cur == '\'')
447 *out++ = *cur++;
448 break;
450 case '/':
451 /* Traditional CPP does not recognize comments within
452 literals. */
453 if (!quote && *cur == '*')
455 pfile->out.cur = out;
456 cur = copy_comment (pfile, cur, macro != 0);
457 out = pfile->out.cur;
458 continue;
460 break;
462 case '_':
463 case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
464 case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
465 case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
466 case 's': case 't': case 'u': case 'v': case 'w': case 'x':
467 case 'y': case 'z':
468 case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
469 case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
470 case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
471 case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
472 case 'Y': case 'Z':
473 if (!pfile->state.skipping && (quote == 0 || macro))
475 cpp_hashnode *node;
476 uchar *out_start = out - 1;
478 pfile->out.cur = out_start;
479 node = lex_identifier (pfile, cur - 1);
480 out = pfile->out.cur;
481 cur = CUR (context);
483 if (node->type == NT_MACRO
484 /* Should we expand for ls_answer? */
485 && (lex_state == ls_none || lex_state == ls_fun_open)
486 && !pfile->state.prevent_expansion)
488 /* Macros invalidate MI optimization. */
489 pfile->mi_valid = false;
490 if (! (node->flags & NODE_BUILTIN)
491 && node->value.macro->fun_like)
493 maybe_start_funlike (pfile, node, out_start, &fmacro);
494 lex_state = ls_fun_open;
495 fmacro.line = pfile->line_table->highest_line;
496 continue;
498 else if (!recursive_macro (pfile, node))
500 /* Remove the object-like macro's name from the
501 output, and push its replacement text. */
502 pfile->out.cur = out_start;
503 push_replacement_text (pfile, node);
504 lex_state = ls_none;
505 goto new_context;
508 else if (macro && (node->flags & NODE_MACRO_ARG) != 0)
510 /* Found a parameter in the replacement text of a
511 #define. Remove its name from the output. */
512 pfile->out.cur = out_start;
513 save_replacement_text (pfile, macro, node->value.arg_index);
514 out = pfile->out.base;
516 else if (lex_state == ls_hash)
518 lex_state = ls_predicate;
519 continue;
521 else if (pfile->state.in_expression
522 && node == pfile->spec_nodes.n_defined)
524 lex_state = ls_defined;
525 continue;
528 break;
530 case '(':
531 if (quote == 0)
533 paren_depth++;
534 if (lex_state == ls_fun_open)
536 if (recursive_macro (pfile, fmacro.node))
537 lex_state = ls_none;
538 else
540 lex_state = ls_fun_close;
541 paren_depth = 1;
542 out = pfile->out.base + fmacro.offset;
543 fmacro.args[0] = fmacro.offset;
546 else if (lex_state == ls_predicate)
547 lex_state = ls_answer;
548 else if (lex_state == ls_defined)
549 lex_state = ls_defined_close;
551 break;
553 case ',':
554 if (quote == 0 && lex_state == ls_fun_close && paren_depth == 1)
555 save_argument (&fmacro, out - pfile->out.base);
556 break;
558 case ')':
559 if (quote == 0)
561 paren_depth--;
562 if (lex_state == ls_fun_close && paren_depth == 0)
564 cpp_macro *m = fmacro.node->value.macro;
566 m->used = 1;
567 lex_state = ls_none;
568 save_argument (&fmacro, out - pfile->out.base);
570 /* A single zero-length argument is no argument. */
571 if (fmacro.argc == 1
572 && m->paramc == 0
573 && out == pfile->out.base + fmacro.offset + 1)
574 fmacro.argc = 0;
576 if (_cpp_arguments_ok (pfile, m, fmacro.node, fmacro.argc))
578 /* Remove the macro's invocation from the
579 output, and push its replacement text. */
580 pfile->out.cur = (pfile->out.base
581 + fmacro.offset);
582 CUR (context) = cur;
583 replace_args_and_push (pfile, &fmacro);
584 goto new_context;
587 else if (lex_state == ls_answer || lex_state == ls_defined_close)
588 lex_state = ls_none;
590 break;
592 case '#':
593 if (cur - 1 == start_of_input_line
594 /* A '#' from a macro doesn't start a directive. */
595 && !pfile->context->prev
596 && !pfile->state.in_directive)
598 /* A directive. With the way _cpp_handle_directive
599 currently works, we only want to call it if either we
600 know the directive is OK, or we want it to fail and
601 be removed from the output. If we want it to be
602 passed through (the assembler case) then we must not
603 call _cpp_handle_directive. */
604 pfile->out.cur = out;
605 cur = skip_whitespace (pfile, cur, true /* skip_comments */);
606 out = pfile->out.cur;
608 if (*cur == '\n')
610 /* Null directive. Ignore it and don't invalidate
611 the MI optimization. */
612 pfile->buffer->need_line = true;
613 CPP_INCREMENT_LINE (pfile, 0);
614 result = false;
615 goto done;
617 else
619 bool do_it = false;
621 if (is_numstart (*cur)
622 && CPP_OPTION (pfile, lang) != CLK_ASM)
623 do_it = true;
624 else if (is_idstart (*cur))
625 /* Check whether we know this directive, but don't
626 advance. */
627 do_it = lex_identifier (pfile, cur)->is_directive;
629 if (do_it || CPP_OPTION (pfile, lang) != CLK_ASM)
631 /* This is a kludge. We want to have the ISO
632 preprocessor lex the next token. */
633 pfile->buffer->cur = cur;
634 _cpp_handle_directive (pfile, false /* indented */);
635 result = false;
636 goto done;
641 if (pfile->state.in_expression)
643 lex_state = ls_hash;
644 continue;
646 break;
648 default:
649 break;
652 /* Non-whitespace disables MI optimization and stops treating
653 '<' as a quote in #include. */
654 header_ok = false;
655 if (!pfile->state.in_directive)
656 pfile->mi_valid = false;
658 if (lex_state == ls_none)
659 continue;
661 /* Some of these transitions of state are syntax errors. The
662 ISO preprocessor will issue errors later. */
663 if (lex_state == ls_fun_open)
664 /* Missing '('. */
665 lex_state = ls_none;
666 else if (lex_state == ls_hash
667 || lex_state == ls_predicate
668 || lex_state == ls_defined)
669 lex_state = ls_none;
671 /* ls_answer and ls_defined_close keep going until ')'. */
674 done:
675 if (fmacro.buff)
676 _cpp_release_buff (pfile, fmacro.buff);
678 if (lex_state == ls_fun_close)
679 cpp_error_with_line (pfile, CPP_DL_ERROR, fmacro.line, 0,
680 "unterminated argument list invoking macro \"%s\"",
681 NODE_NAME (fmacro.node));
682 return result;
685 /* Push a context holding the replacement text of the macro NODE on
686 the context stack. NODE is either object-like, or a function-like
687 macro with no arguments. */
688 static void
689 push_replacement_text (cpp_reader *pfile, cpp_hashnode *node)
691 size_t len;
692 const uchar *text;
693 uchar *buf;
695 if (node->flags & NODE_BUILTIN)
697 text = _cpp_builtin_macro_text (pfile, node);
698 len = ustrlen (text);
699 buf = _cpp_unaligned_alloc (pfile, len + 1);
700 memcpy (buf, text, len);
701 buf[len]='\n';
702 text = buf;
704 else
706 cpp_macro *macro = node->value.macro;
707 macro->used = 1;
708 text = macro->exp.text;
709 macro->traditional = 1;
710 len = macro->count;
713 _cpp_push_text_context (pfile, node, text, len);
716 /* Returns TRUE if traditional macro recursion is detected. */
717 static bool
718 recursive_macro (cpp_reader *pfile, cpp_hashnode *node)
720 bool recursing = !!(node->flags & NODE_DISABLED);
722 /* Object-like macros that are already expanding are necessarily
723 recursive.
725 However, it is possible to have traditional function-like macros
726 that are not infinitely recursive but recurse to any given depth.
727 Further, it is easy to construct examples that get ever longer
728 until the point they stop recursing. So there is no easy way to
729 detect true recursion; instead we assume any expansion more than
730 20 deep since the first invocation of this macro must be
731 recursing. */
732 if (recursing && node->value.macro->fun_like)
734 size_t depth = 0;
735 cpp_context *context = pfile->context;
739 depth++;
740 if (context->c.macro == node && depth > 20)
741 break;
742 context = context->prev;
744 while (context);
745 recursing = context != NULL;
748 if (recursing)
749 cpp_error (pfile, CPP_DL_ERROR,
750 "detected recursion whilst expanding macro \"%s\"",
751 NODE_NAME (node));
753 return recursing;
756 /* Return the length of the replacement text of a function-like or
757 object-like non-builtin macro. */
758 size_t
759 _cpp_replacement_text_len (const cpp_macro *macro)
761 size_t len;
763 if (macro->fun_like && (macro->paramc != 0))
765 const uchar *exp;
767 len = 0;
768 for (exp = macro->exp.text;;)
770 struct block *b = (struct block *) exp;
772 len += b->text_len;
773 if (b->arg_index == 0)
774 break;
775 len += NODE_LEN (macro->params[b->arg_index - 1]);
776 exp += BLOCK_LEN (b->text_len);
779 else
780 len = macro->count;
782 return len;
785 /* Copy the replacement text of MACRO to DEST, which must be of
786 sufficient size. It is not NUL-terminated. The next character is
787 returned. */
788 uchar *
789 _cpp_copy_replacement_text (const cpp_macro *macro, uchar *dest)
791 if (macro->fun_like && (macro->paramc != 0))
793 const uchar *exp;
795 for (exp = macro->exp.text;;)
797 struct block *b = (struct block *) exp;
798 cpp_hashnode *param;
800 memcpy (dest, b->text, b->text_len);
801 dest += b->text_len;
802 if (b->arg_index == 0)
803 break;
804 param = macro->params[b->arg_index - 1];
805 memcpy (dest, NODE_NAME (param), NODE_LEN (param));
806 dest += NODE_LEN (param);
807 exp += BLOCK_LEN (b->text_len);
810 else
812 memcpy (dest, macro->exp.text, macro->count);
813 dest += macro->count;
816 return dest;
819 /* Push a context holding the replacement text of the macro NODE on
820 the context stack. NODE is either object-like, or a function-like
821 macro with no arguments. */
822 static void
823 replace_args_and_push (cpp_reader *pfile, struct fun_macro *fmacro)
825 cpp_macro *macro = fmacro->node->value.macro;
827 if (macro->paramc == 0)
828 push_replacement_text (pfile, fmacro->node);
829 else
831 const uchar *exp;
832 uchar *p;
833 _cpp_buff *buff;
834 size_t len = 0;
835 int cxtquote = 0;
837 /* Get an estimate of the length of the argument-replaced text.
838 This is a worst case estimate, assuming that every replacement
839 text character needs quoting. */
840 for (exp = macro->exp.text;;)
842 struct block *b = (struct block *) exp;
844 len += b->text_len;
845 if (b->arg_index == 0)
846 break;
847 len += 2 * (fmacro->args[b->arg_index]
848 - fmacro->args[b->arg_index - 1] - 1);
849 exp += BLOCK_LEN (b->text_len);
852 /* Allocate room for the expansion plus \n. */
853 buff = _cpp_get_buff (pfile, len + 1);
855 /* Copy the expansion and replace arguments. */
856 /* Accumulate actual length, including quoting as necessary */
857 p = BUFF_FRONT (buff);
858 len = 0;
859 for (exp = macro->exp.text;;)
861 struct block *b = (struct block *) exp;
862 size_t arglen;
863 int argquote;
864 uchar *base;
865 uchar *in;
867 len += b->text_len;
868 /* Copy the non-argument text literally, keeping
869 track of whether matching quotes have been seen. */
870 for (arglen = b->text_len, in = b->text; arglen > 0; arglen--)
872 if (*in == '"')
873 cxtquote = ! cxtquote;
874 *p++ = *in++;
876 /* Done if no more arguments */
877 if (b->arg_index == 0)
878 break;
879 arglen = (fmacro->args[b->arg_index]
880 - fmacro->args[b->arg_index - 1] - 1);
881 base = pfile->out.base + fmacro->args[b->arg_index - 1];
882 in = base;
883 #if 0
884 /* Skip leading whitespace in the text for the argument to
885 be substituted. To be compatible with gcc 2.95, we would
886 also need to trim trailing whitespace. Gcc 2.95 trims
887 leading and trailing whitespace, which may be a bug. The
888 current gcc testsuite explicitly checks that this leading
889 and trailing whitespace in actual arguments is
890 preserved. */
891 while (arglen > 0 && is_space (*in))
893 in++;
894 arglen--;
896 #endif
897 for (argquote = 0; arglen > 0; arglen--)
899 if (cxtquote && *in == '"')
901 if (in > base && *(in-1) != '\\')
902 argquote = ! argquote;
903 /* Always add backslash before double quote if argument
904 is expanded in a quoted context */
905 *p++ = '\\';
906 len++;
908 else if (cxtquote && argquote && *in == '\\')
910 /* Always add backslash before a backslash in an argument
911 that is expanded in a quoted context and also in the
912 range of a quoted context in the argument itself. */
913 *p++ = '\\';
914 len++;
916 *p++ = *in++;
917 len++;
919 exp += BLOCK_LEN (b->text_len);
922 /* \n-terminate. */
923 *p = '\n';
924 _cpp_push_text_context (pfile, fmacro->node, BUFF_FRONT (buff), len);
926 /* So we free buffer allocation when macro is left. */
927 pfile->context->buff = buff;
931 /* Read and record the parameters, if any, of a function-like macro
932 definition. Destroys pfile->out.cur.
934 Returns true on success, false on failure (syntax error or a
935 duplicate parameter). On success, CUR (pfile->context) is just
936 past the closing parenthesis. */
937 static bool
938 scan_parameters (cpp_reader *pfile, cpp_macro *macro)
940 const uchar *cur = CUR (pfile->context) + 1;
941 bool ok;
943 for (;;)
945 cur = skip_whitespace (pfile, cur, true /* skip_comments */);
947 if (is_idstart (*cur))
949 ok = false;
950 if (_cpp_save_parameter (pfile, macro, lex_identifier (pfile, cur)))
951 break;
952 cur = skip_whitespace (pfile, CUR (pfile->context),
953 true /* skip_comments */);
954 if (*cur == ',')
956 cur++;
957 continue;
959 ok = (*cur == ')');
960 break;
963 ok = (*cur == ')' && macro->paramc == 0);
964 break;
967 if (!ok)
968 cpp_error (pfile, CPP_DL_ERROR, "syntax error in macro parameter list");
970 CUR (pfile->context) = cur + (*cur == ')');
972 return ok;
975 /* Save the text from pfile->out.base to pfile->out.cur as
976 the replacement text for the current macro, followed by argument
977 ARG_INDEX, with zero indicating the end of the replacement
978 text. */
979 static void
980 save_replacement_text (cpp_reader *pfile, cpp_macro *macro,
981 unsigned int arg_index)
983 size_t len = pfile->out.cur - pfile->out.base;
984 uchar *exp;
986 if (macro->paramc == 0)
988 /* Object-like and function-like macros without parameters
989 simply store their \n-terminated replacement text. */
990 exp = _cpp_unaligned_alloc (pfile, len + 1);
991 memcpy (exp, pfile->out.base, len);
992 exp[len] = '\n';
993 macro->exp.text = exp;
994 macro->traditional = 1;
995 macro->count = len;
997 else
999 /* Store the text's length (unsigned int), the argument index
1000 (unsigned short, base 1) and then the text. */
1001 size_t blen = BLOCK_LEN (len);
1002 struct block *block;
1004 if (macro->count + blen > BUFF_ROOM (pfile->a_buff))
1005 _cpp_extend_buff (pfile, &pfile->a_buff, macro->count + blen);
1007 exp = BUFF_FRONT (pfile->a_buff);
1008 block = (struct block *) (exp + macro->count);
1009 macro->exp.text = exp;
1010 macro->traditional = 1;
1012 /* Write out the block information. */
1013 block->text_len = len;
1014 block->arg_index = arg_index;
1015 memcpy (block->text, pfile->out.base, len);
1017 /* Lex the rest into the start of the output buffer. */
1018 pfile->out.cur = pfile->out.base;
1020 macro->count += blen;
1022 /* If we've finished, commit the memory. */
1023 if (arg_index == 0)
1024 BUFF_FRONT (pfile->a_buff) += macro->count;
1028 /* Analyze and save the replacement text of a macro. Returns true on
1029 success. */
1030 bool
1031 _cpp_create_trad_definition (cpp_reader *pfile, cpp_macro *macro)
1033 const uchar *cur;
1034 uchar *limit;
1035 cpp_context *context = pfile->context;
1037 /* The context has not been set up for command line defines, and CUR
1038 has not been updated for the macro name for in-file defines. */
1039 pfile->out.cur = pfile->out.base;
1040 CUR (context) = pfile->buffer->cur;
1041 RLIMIT (context) = pfile->buffer->rlimit;
1042 check_output_buffer (pfile, RLIMIT (context) - CUR (context));
1044 /* Is this a function-like macro? */
1045 if (* CUR (context) == '(')
1047 bool ok = scan_parameters (pfile, macro);
1049 /* Remember the params so we can clear NODE_MACRO_ARG flags. */
1050 macro->params = (cpp_hashnode **) BUFF_FRONT (pfile->a_buff);
1052 /* Setting macro to NULL indicates an error occurred, and
1053 prevents unnecessary work in _cpp_scan_out_logical_line. */
1054 if (!ok)
1055 macro = NULL;
1056 else
1058 BUFF_FRONT (pfile->a_buff) = (uchar *) &macro->params[macro->paramc];
1059 macro->fun_like = 1;
1063 /* Skip leading whitespace in the replacement text. */
1064 pfile->buffer->cur
1065 = skip_whitespace (pfile, CUR (context),
1066 CPP_OPTION (pfile, discard_comments_in_macro_exp));
1068 pfile->state.prevent_expansion++;
1069 _cpp_scan_out_logical_line (pfile, macro);
1070 pfile->state.prevent_expansion--;
1072 if (!macro)
1073 return false;
1075 /* Skip trailing white space. */
1076 cur = pfile->out.base;
1077 limit = pfile->out.cur;
1078 while (limit > cur && is_space (limit[-1]))
1079 limit--;
1080 pfile->out.cur = limit;
1081 save_replacement_text (pfile, macro, 0);
1083 return true;
1086 /* Copy SRC of length LEN to DEST, but convert all contiguous
1087 whitespace to a single space, provided it is not in quotes. The
1088 quote currently in effect is pointed to by PQUOTE, and is updated
1089 by the function. Returns the number of bytes copied. */
1090 static size_t
1091 canonicalize_text (uchar *dest, const uchar *src, size_t len, uchar *pquote)
1093 uchar *orig_dest = dest;
1094 uchar quote = *pquote;
1096 while (len)
1098 if (is_space (*src) && !quote)
1101 src++, len--;
1102 while (len && is_space (*src));
1103 *dest++ = ' ';
1105 else
1107 if (*src == '\'' || *src == '"')
1109 if (!quote)
1110 quote = *src;
1111 else if (quote == *src)
1112 quote = 0;
1114 *dest++ = *src++, len--;
1118 *pquote = quote;
1119 return dest - orig_dest;
1122 /* Returns true if MACRO1 and MACRO2 have expansions different other
1123 than in the form of their whitespace. */
1124 bool
1125 _cpp_expansions_different_trad (const cpp_macro *macro1,
1126 const cpp_macro *macro2)
1128 uchar *p1 = XNEWVEC (uchar, macro1->count + macro2->count);
1129 uchar *p2 = p1 + macro1->count;
1130 uchar quote1 = 0, quote2 = 0;
1131 bool mismatch;
1132 size_t len1, len2;
1134 if (macro1->paramc > 0)
1136 const uchar *exp1 = macro1->exp.text, *exp2 = macro2->exp.text;
1138 mismatch = true;
1139 for (;;)
1141 struct block *b1 = (struct block *) exp1;
1142 struct block *b2 = (struct block *) exp2;
1144 if (b1->arg_index != b2->arg_index)
1145 break;
1147 len1 = canonicalize_text (p1, b1->text, b1->text_len, &quote1);
1148 len2 = canonicalize_text (p2, b2->text, b2->text_len, &quote2);
1149 if (len1 != len2 || memcmp (p1, p2, len1))
1150 break;
1151 if (b1->arg_index == 0)
1153 mismatch = false;
1154 break;
1156 exp1 += BLOCK_LEN (b1->text_len);
1157 exp2 += BLOCK_LEN (b2->text_len);
1160 else
1162 len1 = canonicalize_text (p1, macro1->exp.text, macro1->count, &quote1);
1163 len2 = canonicalize_text (p2, macro2->exp.text, macro2->count, &quote2);
1164 mismatch = (len1 != len2 || memcmp (p1, p2, len1));
1167 free (p1);
1168 return mismatch;