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ec2bcbe7 | 1 | /* C preprocessor macro expansion for GDB. |
6aba47ca | 2 | Copyright (C) 2002, 2007 Free Software Foundation, Inc. |
ec2bcbe7 JB |
3 | Contributed by Red Hat, Inc. |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any 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; if not, write to the Free Software | |
197e01b6 EZ |
19 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
20 | Boston, MA 02110-1301, USA. */ | |
ec2bcbe7 JB |
21 | |
22 | #include "defs.h" | |
04ea0df1 | 23 | #include "gdb_obstack.h" |
ec2bcbe7 JB |
24 | #include "bcache.h" |
25 | #include "macrotab.h" | |
26 | #include "macroexp.h" | |
27 | #include "gdb_assert.h" | |
28 | ||
29 | ||
30 | \f | |
31 | /* A resizeable, substringable string type. */ | |
32 | ||
33 | ||
34 | /* A string type that we can resize, quickly append to, and use to | |
35 | refer to substrings of other strings. */ | |
36 | struct macro_buffer | |
37 | { | |
38 | /* An array of characters. The first LEN bytes are the real text, | |
39 | but there are SIZE bytes allocated to the array. If SIZE is | |
40 | zero, then this doesn't point to a malloc'ed block. If SHARED is | |
41 | non-zero, then this buffer is actually a pointer into some larger | |
42 | string, and we shouldn't append characters to it, etc. Because | |
43 | of sharing, we can't assume in general that the text is | |
44 | null-terminated. */ | |
45 | char *text; | |
46 | ||
47 | /* The number of characters in the string. */ | |
48 | int len; | |
49 | ||
50 | /* The number of characters allocated to the string. If SHARED is | |
51 | non-zero, this is meaningless; in this case, we set it to zero so | |
52 | that any "do we have room to append something?" tests will fail, | |
53 | so we don't always have to check SHARED before using this field. */ | |
54 | int size; | |
55 | ||
56 | /* Zero if TEXT can be safely realloc'ed (i.e., it's its own malloc | |
57 | block). Non-zero if TEXT is actually pointing into the middle of | |
58 | some other block, and we shouldn't reallocate it. */ | |
59 | int shared; | |
60 | ||
61 | /* For detecting token splicing. | |
62 | ||
63 | This is the index in TEXT of the first character of the token | |
64 | that abuts the end of TEXT. If TEXT contains no tokens, then we | |
65 | set this equal to LEN. If TEXT ends in whitespace, then there is | |
66 | no token abutting the end of TEXT (it's just whitespace), and | |
67 | again, we set this equal to LEN. We set this to -1 if we don't | |
68 | know the nature of TEXT. */ | |
69 | int last_token; | |
70 | ||
71 | /* If this buffer is holding the result from get_token, then this | |
72 | is non-zero if it is an identifier token, zero otherwise. */ | |
73 | int is_identifier; | |
74 | }; | |
75 | ||
76 | ||
77 | /* Set the macro buffer *B to the empty string, guessing that its | |
78 | final contents will fit in N bytes. (It'll get resized if it | |
79 | doesn't, so the guess doesn't have to be right.) Allocate the | |
80 | initial storage with xmalloc. */ | |
81 | static void | |
82 | init_buffer (struct macro_buffer *b, int n) | |
83 | { | |
84 | /* Small value for initial testing. */ | |
85 | n = 1; | |
86 | ||
87 | b->size = n; | |
88 | if (n > 0) | |
89 | b->text = (char *) xmalloc (n); | |
90 | else | |
a86bc61c | 91 | b->text = NULL; |
ec2bcbe7 JB |
92 | b->len = 0; |
93 | b->shared = 0; | |
94 | b->last_token = -1; | |
95 | } | |
96 | ||
97 | ||
98 | /* Set the macro buffer *BUF to refer to the LEN bytes at ADDR, as a | |
99 | shared substring. */ | |
100 | static void | |
101 | init_shared_buffer (struct macro_buffer *buf, char *addr, int len) | |
102 | { | |
103 | buf->text = addr; | |
104 | buf->len = len; | |
105 | buf->shared = 1; | |
106 | buf->size = 0; | |
107 | buf->last_token = -1; | |
108 | } | |
109 | ||
110 | ||
111 | /* Free the text of the buffer B. Raise an error if B is shared. */ | |
112 | static void | |
113 | free_buffer (struct macro_buffer *b) | |
114 | { | |
115 | gdb_assert (! b->shared); | |
116 | if (b->size) | |
117 | xfree (b->text); | |
118 | } | |
119 | ||
120 | ||
121 | /* A cleanup function for macro buffers. */ | |
122 | static void | |
123 | cleanup_macro_buffer (void *untyped_buf) | |
124 | { | |
125 | free_buffer ((struct macro_buffer *) untyped_buf); | |
126 | } | |
127 | ||
128 | ||
129 | /* Resize the buffer B to be at least N bytes long. Raise an error if | |
130 | B shouldn't be resized. */ | |
131 | static void | |
132 | resize_buffer (struct macro_buffer *b, int n) | |
133 | { | |
134 | /* We shouldn't be trying to resize shared strings. */ | |
135 | gdb_assert (! b->shared); | |
136 | ||
137 | if (b->size == 0) | |
138 | b->size = n; | |
139 | else | |
140 | while (b->size <= n) | |
141 | b->size *= 2; | |
142 | ||
143 | b->text = xrealloc (b->text, b->size); | |
144 | } | |
145 | ||
146 | ||
147 | /* Append the character C to the buffer B. */ | |
39efb398 | 148 | static void |
ec2bcbe7 JB |
149 | appendc (struct macro_buffer *b, int c) |
150 | { | |
151 | int new_len = b->len + 1; | |
152 | ||
153 | if (new_len > b->size) | |
154 | resize_buffer (b, new_len); | |
155 | ||
156 | b->text[b->len] = c; | |
157 | b->len = new_len; | |
158 | } | |
159 | ||
160 | ||
161 | /* Append the LEN bytes at ADDR to the buffer B. */ | |
39efb398 | 162 | static void |
ec2bcbe7 JB |
163 | appendmem (struct macro_buffer *b, char *addr, int len) |
164 | { | |
165 | int new_len = b->len + len; | |
166 | ||
167 | if (new_len > b->size) | |
168 | resize_buffer (b, new_len); | |
169 | ||
170 | memcpy (b->text + b->len, addr, len); | |
171 | b->len = new_len; | |
172 | } | |
173 | ||
174 | ||
175 | \f | |
176 | /* Recognizing preprocessor tokens. */ | |
177 | ||
178 | ||
179 | static int | |
180 | is_whitespace (int c) | |
181 | { | |
182 | return (c == ' ' | |
183 | || c == '\t' | |
184 | || c == '\n' | |
185 | || c == '\v' | |
186 | || c == '\f'); | |
187 | } | |
188 | ||
189 | ||
190 | static int | |
191 | is_digit (int c) | |
192 | { | |
193 | return ('0' <= c && c <= '9'); | |
194 | } | |
195 | ||
196 | ||
197 | static int | |
198 | is_identifier_nondigit (int c) | |
199 | { | |
200 | return (c == '_' | |
201 | || ('a' <= c && c <= 'z') | |
202 | || ('A' <= c && c <= 'Z')); | |
203 | } | |
204 | ||
205 | ||
206 | static void | |
207 | set_token (struct macro_buffer *tok, char *start, char *end) | |
208 | { | |
209 | init_shared_buffer (tok, start, end - start); | |
210 | tok->last_token = 0; | |
211 | ||
212 | /* Presumed; get_identifier may overwrite this. */ | |
213 | tok->is_identifier = 0; | |
214 | } | |
215 | ||
216 | ||
217 | static int | |
218 | get_comment (struct macro_buffer *tok, char *p, char *end) | |
219 | { | |
220 | if (p + 2 > end) | |
221 | return 0; | |
222 | else if (p[0] == '/' | |
223 | && p[1] == '*') | |
224 | { | |
225 | char *tok_start = p; | |
226 | ||
227 | p += 2; | |
228 | ||
229 | for (; p < end; p++) | |
230 | if (p + 2 <= end | |
231 | && p[0] == '*' | |
232 | && p[1] == '/') | |
233 | { | |
234 | p += 2; | |
235 | set_token (tok, tok_start, p); | |
236 | return 1; | |
237 | } | |
238 | ||
8a3fe4f8 | 239 | error (_("Unterminated comment in macro expansion.")); |
ec2bcbe7 JB |
240 | } |
241 | else if (p[0] == '/' | |
242 | && p[1] == '/') | |
243 | { | |
244 | char *tok_start = p; | |
245 | ||
246 | p += 2; | |
247 | for (; p < end; p++) | |
248 | if (*p == '\n') | |
249 | break; | |
250 | ||
251 | set_token (tok, tok_start, p); | |
252 | return 1; | |
253 | } | |
254 | else | |
255 | return 0; | |
256 | } | |
257 | ||
258 | ||
259 | static int | |
260 | get_identifier (struct macro_buffer *tok, char *p, char *end) | |
261 | { | |
262 | if (p < end | |
263 | && is_identifier_nondigit (*p)) | |
264 | { | |
265 | char *tok_start = p; | |
266 | ||
267 | while (p < end | |
268 | && (is_identifier_nondigit (*p) | |
269 | || is_digit (*p))) | |
270 | p++; | |
271 | ||
272 | set_token (tok, tok_start, p); | |
273 | tok->is_identifier = 1; | |
274 | return 1; | |
275 | } | |
276 | else | |
277 | return 0; | |
278 | } | |
279 | ||
280 | ||
281 | static int | |
282 | get_pp_number (struct macro_buffer *tok, char *p, char *end) | |
283 | { | |
284 | if (p < end | |
285 | && (is_digit (*p) | |
286 | || *p == '.')) | |
287 | { | |
288 | char *tok_start = p; | |
289 | ||
290 | while (p < end) | |
291 | { | |
292 | if (is_digit (*p) | |
293 | || is_identifier_nondigit (*p) | |
294 | || *p == '.') | |
295 | p++; | |
296 | else if (p + 2 <= end | |
297 | && strchr ("eEpP.", *p) | |
298 | && (p[1] == '+' || p[1] == '-')) | |
299 | p += 2; | |
300 | else | |
301 | break; | |
302 | } | |
303 | ||
304 | set_token (tok, tok_start, p); | |
305 | return 1; | |
306 | } | |
307 | else | |
308 | return 0; | |
309 | } | |
310 | ||
311 | ||
312 | ||
313 | /* If the text starting at P going up to (but not including) END | |
314 | starts with a character constant, set *TOK to point to that | |
315 | character constant, and return 1. Otherwise, return zero. | |
316 | Signal an error if it contains a malformed or incomplete character | |
317 | constant. */ | |
318 | static int | |
319 | get_character_constant (struct macro_buffer *tok, char *p, char *end) | |
320 | { | |
321 | /* ISO/IEC 9899:1999 (E) Section 6.4.4.4 paragraph 1 | |
322 | But of course, what really matters is that we handle it the same | |
323 | way GDB's C/C++ lexer does. So we call parse_escape in utils.c | |
324 | to handle escape sequences. */ | |
325 | if ((p + 1 <= end && *p == '\'') | |
326 | || (p + 2 <= end && p[0] == 'L' && p[1] == '\'')) | |
327 | { | |
328 | char *tok_start = p; | |
329 | char *body_start; | |
330 | ||
331 | if (*p == '\'') | |
332 | p++; | |
333 | else if (*p == 'L') | |
334 | p += 2; | |
335 | else | |
336 | gdb_assert (0); | |
337 | ||
338 | body_start = p; | |
339 | for (;;) | |
340 | { | |
341 | if (p >= end) | |
8a3fe4f8 | 342 | error (_("Unmatched single quote.")); |
ec2bcbe7 JB |
343 | else if (*p == '\'') |
344 | { | |
345 | if (p == body_start) | |
8a3fe4f8 AC |
346 | error (_("A character constant must contain at least one " |
347 | "character.")); | |
ec2bcbe7 JB |
348 | p++; |
349 | break; | |
350 | } | |
351 | else if (*p == '\\') | |
352 | { | |
353 | p++; | |
354 | parse_escape (&p); | |
355 | } | |
356 | else | |
357 | p++; | |
358 | } | |
359 | ||
360 | set_token (tok, tok_start, p); | |
361 | return 1; | |
362 | } | |
363 | else | |
364 | return 0; | |
365 | } | |
366 | ||
367 | ||
368 | /* If the text starting at P going up to (but not including) END | |
369 | starts with a string literal, set *TOK to point to that string | |
370 | literal, and return 1. Otherwise, return zero. Signal an error if | |
371 | it contains a malformed or incomplete string literal. */ | |
372 | static int | |
373 | get_string_literal (struct macro_buffer *tok, char *p, char *end) | |
374 | { | |
375 | if ((p + 1 <= end | |
376 | && *p == '\"') | |
377 | || (p + 2 <= end | |
378 | && p[0] == 'L' | |
379 | && p[1] == '\"')) | |
380 | { | |
381 | char *tok_start = p; | |
382 | ||
383 | if (*p == '\"') | |
384 | p++; | |
385 | else if (*p == 'L') | |
386 | p += 2; | |
387 | else | |
388 | gdb_assert (0); | |
389 | ||
390 | for (;;) | |
391 | { | |
392 | if (p >= end) | |
8a3fe4f8 | 393 | error (_("Unterminated string in expression.")); |
ec2bcbe7 JB |
394 | else if (*p == '\"') |
395 | { | |
396 | p++; | |
397 | break; | |
398 | } | |
399 | else if (*p == '\n') | |
8a3fe4f8 AC |
400 | error (_("Newline characters may not appear in string " |
401 | "constants.")); | |
ec2bcbe7 JB |
402 | else if (*p == '\\') |
403 | { | |
404 | p++; | |
405 | parse_escape (&p); | |
406 | } | |
407 | else | |
408 | p++; | |
409 | } | |
410 | ||
411 | set_token (tok, tok_start, p); | |
412 | return 1; | |
413 | } | |
414 | else | |
415 | return 0; | |
416 | } | |
417 | ||
418 | ||
419 | static int | |
420 | get_punctuator (struct macro_buffer *tok, char *p, char *end) | |
421 | { | |
422 | /* Here, speed is much less important than correctness and clarity. */ | |
423 | ||
424 | /* ISO/IEC 9899:1999 (E) Section 6.4.6 Paragraph 1 */ | |
425 | static const char * const punctuators[] = { | |
426 | "[", "]", "(", ")", "{", "}", ".", "->", | |
427 | "++", "--", "&", "*", "+", "-", "~", "!", | |
428 | "/", "%", "<<", ">>", "<", ">", "<=", ">=", "==", "!=", | |
429 | "^", "|", "&&", "||", | |
430 | "?", ":", ";", "...", | |
431 | "=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|=", | |
432 | ",", "#", "##", | |
433 | "<:", ":>", "<%", "%>", "%:", "%:%:", | |
434 | 0 | |
435 | }; | |
436 | ||
437 | int i; | |
438 | ||
439 | if (p + 1 <= end) | |
440 | { | |
441 | for (i = 0; punctuators[i]; i++) | |
442 | { | |
443 | const char *punctuator = punctuators[i]; | |
444 | ||
445 | if (p[0] == punctuator[0]) | |
446 | { | |
447 | int len = strlen (punctuator); | |
448 | ||
449 | if (p + len <= end | |
450 | && ! memcmp (p, punctuator, len)) | |
451 | { | |
452 | set_token (tok, p, p + len); | |
453 | return 1; | |
454 | } | |
455 | } | |
456 | } | |
457 | } | |
458 | ||
459 | return 0; | |
460 | } | |
461 | ||
462 | ||
463 | /* Peel the next preprocessor token off of SRC, and put it in TOK. | |
464 | Mutate TOK to refer to the first token in SRC, and mutate SRC to | |
465 | refer to the text after that token. SRC must be a shared buffer; | |
466 | the resulting TOK will be shared, pointing into the same string SRC | |
467 | does. Initialize TOK's last_token field. Return non-zero if we | |
468 | succeed, or 0 if we didn't find any more tokens in SRC. */ | |
469 | static int | |
470 | get_token (struct macro_buffer *tok, | |
471 | struct macro_buffer *src) | |
472 | { | |
473 | char *p = src->text; | |
474 | char *end = p + src->len; | |
475 | ||
476 | gdb_assert (src->shared); | |
477 | ||
478 | /* From the ISO C standard, ISO/IEC 9899:1999 (E), section 6.4: | |
479 | ||
480 | preprocessing-token: | |
481 | header-name | |
482 | identifier | |
483 | pp-number | |
484 | character-constant | |
485 | string-literal | |
486 | punctuator | |
487 | each non-white-space character that cannot be one of the above | |
488 | ||
489 | We don't have to deal with header-name tokens, since those can | |
490 | only occur after a #include, which we will never see. */ | |
491 | ||
492 | while (p < end) | |
493 | if (is_whitespace (*p)) | |
494 | p++; | |
495 | else if (get_comment (tok, p, end)) | |
496 | p += tok->len; | |
497 | else if (get_pp_number (tok, p, end) | |
498 | || get_character_constant (tok, p, end) | |
499 | || get_string_literal (tok, p, end) | |
500 | /* Note: the grammar in the standard seems to be | |
501 | ambiguous: L'x' can be either a wide character | |
502 | constant, or an identifier followed by a normal | |
503 | character constant. By trying `get_identifier' after | |
504 | we try get_character_constant and get_string_literal, | |
505 | we give the wide character syntax precedence. Now, | |
506 | since GDB doesn't handle wide character constants | |
507 | anyway, is this the right thing to do? */ | |
508 | || get_identifier (tok, p, end) | |
509 | || get_punctuator (tok, p, end)) | |
510 | { | |
511 | /* How many characters did we consume, including whitespace? */ | |
512 | int consumed = p - src->text + tok->len; | |
513 | src->text += consumed; | |
514 | src->len -= consumed; | |
515 | return 1; | |
516 | } | |
517 | else | |
518 | { | |
519 | /* We have found a "non-whitespace character that cannot be | |
520 | one of the above." Make a token out of it. */ | |
521 | int consumed; | |
522 | ||
523 | set_token (tok, p, p + 1); | |
524 | consumed = p - src->text + tok->len; | |
525 | src->text += consumed; | |
526 | src->len -= consumed; | |
527 | return 1; | |
528 | } | |
529 | ||
530 | return 0; | |
531 | } | |
532 | ||
533 | ||
534 | \f | |
535 | /* Appending token strings, with and without splicing */ | |
536 | ||
537 | ||
538 | /* Append the macro buffer SRC to the end of DEST, and ensure that | |
539 | doing so doesn't splice the token at the end of SRC with the token | |
540 | at the beginning of DEST. SRC and DEST must have their last_token | |
541 | fields set. Upon return, DEST's last_token field is set correctly. | |
542 | ||
543 | For example: | |
544 | ||
545 | If DEST is "(" and SRC is "y", then we can return with | |
546 | DEST set to "(y" --- we've simply appended the two buffers. | |
547 | ||
548 | However, if DEST is "x" and SRC is "y", then we must not return | |
549 | with DEST set to "xy" --- that would splice the two tokens "x" and | |
550 | "y" together to make a single token "xy". However, it would be | |
551 | fine to return with DEST set to "x y". Similarly, "<" and "<" must | |
552 | yield "< <", not "<<", etc. */ | |
553 | static void | |
554 | append_tokens_without_splicing (struct macro_buffer *dest, | |
555 | struct macro_buffer *src) | |
556 | { | |
557 | int original_dest_len = dest->len; | |
558 | struct macro_buffer dest_tail, new_token; | |
559 | ||
560 | gdb_assert (src->last_token != -1); | |
561 | gdb_assert (dest->last_token != -1); | |
562 | ||
563 | /* First, just try appending the two, and call get_token to see if | |
564 | we got a splice. */ | |
565 | appendmem (dest, src->text, src->len); | |
566 | ||
567 | /* If DEST originally had no token abutting its end, then we can't | |
568 | have spliced anything, so we're done. */ | |
569 | if (dest->last_token == original_dest_len) | |
570 | { | |
571 | dest->last_token = original_dest_len + src->last_token; | |
572 | return; | |
573 | } | |
574 | ||
575 | /* Set DEST_TAIL to point to the last token in DEST, followed by | |
576 | all the stuff we just appended. */ | |
577 | init_shared_buffer (&dest_tail, | |
578 | dest->text + dest->last_token, | |
579 | dest->len - dest->last_token); | |
580 | ||
581 | /* Re-parse DEST's last token. We know that DEST used to contain | |
582 | at least one token, so if it doesn't contain any after the | |
583 | append, then we must have spliced "/" and "*" or "/" and "/" to | |
584 | make a comment start. (Just for the record, I got this right | |
585 | the first time. This is not a bug fix.) */ | |
586 | if (get_token (&new_token, &dest_tail) | |
587 | && (new_token.text + new_token.len | |
588 | == dest->text + original_dest_len)) | |
589 | { | |
590 | /* No splice, so we're done. */ | |
591 | dest->last_token = original_dest_len + src->last_token; | |
592 | return; | |
593 | } | |
594 | ||
595 | /* Okay, a simple append caused a splice. Let's chop dest back to | |
596 | its original length and try again, but separate the texts with a | |
597 | space. */ | |
598 | dest->len = original_dest_len; | |
599 | appendc (dest, ' '); | |
600 | appendmem (dest, src->text, src->len); | |
601 | ||
602 | init_shared_buffer (&dest_tail, | |
603 | dest->text + dest->last_token, | |
604 | dest->len - dest->last_token); | |
605 | ||
606 | /* Try to re-parse DEST's last token, as above. */ | |
607 | if (get_token (&new_token, &dest_tail) | |
608 | && (new_token.text + new_token.len | |
609 | == dest->text + original_dest_len)) | |
610 | { | |
611 | /* No splice, so we're done. */ | |
612 | dest->last_token = original_dest_len + 1 + src->last_token; | |
613 | return; | |
614 | } | |
615 | ||
616 | /* As far as I know, there's no case where inserting a space isn't | |
617 | enough to prevent a splice. */ | |
618 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 619 | _("unable to avoid splicing tokens during macro expansion")); |
ec2bcbe7 JB |
620 | } |
621 | ||
622 | ||
623 | \f | |
624 | /* Expanding macros! */ | |
625 | ||
626 | ||
627 | /* A singly-linked list of the names of the macros we are currently | |
628 | expanding --- for detecting expansion loops. */ | |
629 | struct macro_name_list { | |
630 | const char *name; | |
631 | struct macro_name_list *next; | |
632 | }; | |
633 | ||
634 | ||
635 | /* Return non-zero if we are currently expanding the macro named NAME, | |
636 | according to LIST; otherwise, return zero. | |
637 | ||
638 | You know, it would be possible to get rid of all the NO_LOOP | |
639 | arguments to these functions by simply generating a new lookup | |
640 | function and baton which refuses to find the definition for a | |
641 | particular macro, and otherwise delegates the decision to another | |
642 | function/baton pair. But that makes the linked list of excluded | |
643 | macros chained through untyped baton pointers, which will make it | |
644 | harder to debug. :( */ | |
645 | static int | |
646 | currently_rescanning (struct macro_name_list *list, const char *name) | |
647 | { | |
648 | for (; list; list = list->next) | |
a86bc61c | 649 | if (strcmp (name, list->name) == 0) |
ec2bcbe7 JB |
650 | return 1; |
651 | ||
652 | return 0; | |
653 | } | |
654 | ||
655 | ||
656 | /* Gather the arguments to a macro expansion. | |
657 | ||
658 | NAME is the name of the macro being invoked. (It's only used for | |
659 | printing error messages.) | |
660 | ||
661 | Assume that SRC is the text of the macro invocation immediately | |
662 | following the macro name. For example, if we're processing the | |
663 | text foo(bar, baz), then NAME would be foo and SRC will be (bar, | |
664 | baz). | |
665 | ||
666 | If SRC doesn't start with an open paren ( token at all, return | |
667 | zero, leave SRC unchanged, and don't set *ARGC_P to anything. | |
668 | ||
669 | If SRC doesn't contain a properly terminated argument list, then | |
670 | raise an error. | |
671 | ||
672 | Otherwise, return a pointer to the first element of an array of | |
673 | macro buffers referring to the argument texts, and set *ARGC_P to | |
674 | the number of arguments we found --- the number of elements in the | |
675 | array. The macro buffers share their text with SRC, and their | |
676 | last_token fields are initialized. The array is allocated with | |
677 | xmalloc, and the caller is responsible for freeing it. | |
678 | ||
679 | NOTE WELL: if SRC starts with a open paren ( token followed | |
680 | immediately by a close paren ) token (e.g., the invocation looks | |
681 | like "foo()"), we treat that as one argument, which happens to be | |
682 | the empty list of tokens. The caller should keep in mind that such | |
683 | a sequence of tokens is a valid way to invoke one-parameter | |
684 | function-like macros, but also a valid way to invoke zero-parameter | |
685 | function-like macros. Eeew. | |
686 | ||
687 | Consume the tokens from SRC; after this call, SRC contains the text | |
688 | following the invocation. */ | |
689 | ||
690 | static struct macro_buffer * | |
691 | gather_arguments (const char *name, struct macro_buffer *src, int *argc_p) | |
692 | { | |
693 | struct macro_buffer tok; | |
694 | int args_len, args_size; | |
a86bc61c | 695 | struct macro_buffer *args = NULL; |
ec2bcbe7 JB |
696 | struct cleanup *back_to = make_cleanup (free_current_contents, &args); |
697 | ||
698 | /* Does SRC start with an opening paren token? Read from a copy of | |
699 | SRC, so SRC itself is unaffected if we don't find an opening | |
700 | paren. */ | |
701 | { | |
702 | struct macro_buffer temp; | |
703 | init_shared_buffer (&temp, src->text, src->len); | |
704 | ||
705 | if (! get_token (&tok, &temp) | |
706 | || tok.len != 1 | |
707 | || tok.text[0] != '(') | |
708 | { | |
709 | discard_cleanups (back_to); | |
710 | return 0; | |
711 | } | |
712 | } | |
713 | ||
714 | /* Consume SRC's opening paren. */ | |
715 | get_token (&tok, src); | |
716 | ||
717 | args_len = 0; | |
718 | args_size = 1; /* small for initial testing */ | |
719 | args = (struct macro_buffer *) xmalloc (sizeof (*args) * args_size); | |
720 | ||
721 | for (;;) | |
722 | { | |
723 | struct macro_buffer *arg; | |
724 | int depth; | |
725 | ||
726 | /* Make sure we have room for the next argument. */ | |
727 | if (args_len >= args_size) | |
728 | { | |
729 | args_size *= 2; | |
730 | args = xrealloc (args, sizeof (*args) * args_size); | |
731 | } | |
732 | ||
733 | /* Initialize the next argument. */ | |
734 | arg = &args[args_len++]; | |
735 | set_token (arg, src->text, src->text); | |
736 | ||
737 | /* Gather the argument's tokens. */ | |
738 | depth = 0; | |
739 | for (;;) | |
740 | { | |
741 | char *start = src->text; | |
742 | ||
743 | if (! get_token (&tok, src)) | |
8a3fe4f8 | 744 | error (_("Malformed argument list for macro `%s'."), name); |
ec2bcbe7 JB |
745 | |
746 | /* Is tok an opening paren? */ | |
747 | if (tok.len == 1 && tok.text[0] == '(') | |
748 | depth++; | |
749 | ||
750 | /* Is tok is a closing paren? */ | |
751 | else if (tok.len == 1 && tok.text[0] == ')') | |
752 | { | |
753 | /* If it's a closing paren at the top level, then that's | |
754 | the end of the argument list. */ | |
755 | if (depth == 0) | |
756 | { | |
757 | discard_cleanups (back_to); | |
758 | *argc_p = args_len; | |
759 | return args; | |
760 | } | |
761 | ||
762 | depth--; | |
763 | } | |
764 | ||
765 | /* If tok is a comma at top level, then that's the end of | |
766 | the current argument. */ | |
767 | else if (tok.len == 1 && tok.text[0] == ',' && depth == 0) | |
768 | break; | |
769 | ||
770 | /* Extend the current argument to enclose this token. If | |
771 | this is the current argument's first token, leave out any | |
772 | leading whitespace, just for aesthetics. */ | |
773 | if (arg->len == 0) | |
774 | { | |
775 | arg->text = tok.text; | |
776 | arg->len = tok.len; | |
777 | arg->last_token = 0; | |
778 | } | |
779 | else | |
780 | { | |
781 | arg->len = (tok.text + tok.len) - arg->text; | |
782 | arg->last_token = tok.text - arg->text; | |
783 | } | |
784 | } | |
785 | } | |
786 | } | |
787 | ||
788 | ||
789 | /* The `expand' and `substitute_args' functions both invoke `scan' | |
790 | recursively, so we need a forward declaration somewhere. */ | |
791 | static void scan (struct macro_buffer *dest, | |
792 | struct macro_buffer *src, | |
793 | struct macro_name_list *no_loop, | |
794 | macro_lookup_ftype *lookup_func, | |
795 | void *lookup_baton); | |
796 | ||
797 | ||
798 | /* Given the macro definition DEF, being invoked with the actual | |
799 | arguments given by ARGC and ARGV, substitute the arguments into the | |
800 | replacement list, and store the result in DEST. | |
801 | ||
802 | If it is necessary to expand macro invocations in one of the | |
803 | arguments, use LOOKUP_FUNC and LOOKUP_BATON to find the macro | |
804 | definitions, and don't expand invocations of the macros listed in | |
805 | NO_LOOP. */ | |
806 | static void | |
807 | substitute_args (struct macro_buffer *dest, | |
808 | struct macro_definition *def, | |
809 | int argc, struct macro_buffer *argv, | |
810 | struct macro_name_list *no_loop, | |
811 | macro_lookup_ftype *lookup_func, | |
812 | void *lookup_baton) | |
813 | { | |
814 | /* A macro buffer for the macro's replacement list. */ | |
815 | struct macro_buffer replacement_list; | |
816 | ||
817 | init_shared_buffer (&replacement_list, (char *) def->replacement, | |
818 | strlen (def->replacement)); | |
819 | ||
820 | gdb_assert (dest->len == 0); | |
821 | dest->last_token = 0; | |
822 | ||
823 | for (;;) | |
824 | { | |
825 | struct macro_buffer tok; | |
826 | char *original_rl_start = replacement_list.text; | |
827 | int substituted = 0; | |
828 | ||
829 | /* Find the next token in the replacement list. */ | |
830 | if (! get_token (&tok, &replacement_list)) | |
831 | break; | |
832 | ||
833 | /* Just for aesthetics. If we skipped some whitespace, copy | |
834 | that to DEST. */ | |
835 | if (tok.text > original_rl_start) | |
836 | { | |
837 | appendmem (dest, original_rl_start, tok.text - original_rl_start); | |
838 | dest->last_token = dest->len; | |
839 | } | |
840 | ||
841 | /* Is this token the stringification operator? */ | |
842 | if (tok.len == 1 | |
843 | && tok.text[0] == '#') | |
8a3fe4f8 | 844 | error (_("Stringification is not implemented yet.")); |
ec2bcbe7 JB |
845 | |
846 | /* Is this token the splicing operator? */ | |
847 | if (tok.len == 2 | |
848 | && tok.text[0] == '#' | |
849 | && tok.text[1] == '#') | |
8a3fe4f8 | 850 | error (_("Token splicing is not implemented yet.")); |
ec2bcbe7 JB |
851 | |
852 | /* Is this token an identifier? */ | |
853 | if (tok.is_identifier) | |
854 | { | |
855 | int i; | |
856 | ||
857 | /* Is it the magic varargs parameter? */ | |
858 | if (tok.len == 11 | |
859 | && ! memcmp (tok.text, "__VA_ARGS__", 11)) | |
8a3fe4f8 | 860 | error (_("Variable-arity macros not implemented yet.")); |
ec2bcbe7 JB |
861 | |
862 | /* Is it one of the parameters? */ | |
863 | for (i = 0; i < def->argc; i++) | |
864 | if (tok.len == strlen (def->argv[i]) | |
865 | && ! memcmp (tok.text, def->argv[i], tok.len)) | |
866 | { | |
867 | struct macro_buffer arg_src; | |
868 | ||
869 | /* Expand any macro invocations in the argument text, | |
870 | and append the result to dest. Remember that scan | |
871 | mutates its source, so we need to scan a new buffer | |
872 | referring to the argument's text, not the argument | |
873 | itself. */ | |
874 | init_shared_buffer (&arg_src, argv[i].text, argv[i].len); | |
875 | scan (dest, &arg_src, no_loop, lookup_func, lookup_baton); | |
876 | substituted = 1; | |
877 | break; | |
878 | } | |
879 | } | |
880 | ||
881 | /* If it wasn't a parameter, then just copy it across. */ | |
882 | if (! substituted) | |
883 | append_tokens_without_splicing (dest, &tok); | |
884 | } | |
885 | } | |
886 | ||
887 | ||
888 | /* Expand a call to a macro named ID, whose definition is DEF. Append | |
889 | its expansion to DEST. SRC is the input text following the ID | |
890 | token. We are currently rescanning the expansions of the macros | |
891 | named in NO_LOOP; don't re-expand them. Use LOOKUP_FUNC and | |
892 | LOOKUP_BATON to find definitions for any nested macro references. | |
893 | ||
894 | Return 1 if we decided to expand it, zero otherwise. (If it's a | |
895 | function-like macro name that isn't followed by an argument list, | |
896 | we don't expand it.) If we return zero, leave SRC unchanged. */ | |
897 | static int | |
898 | expand (const char *id, | |
899 | struct macro_definition *def, | |
900 | struct macro_buffer *dest, | |
901 | struct macro_buffer *src, | |
902 | struct macro_name_list *no_loop, | |
903 | macro_lookup_ftype *lookup_func, | |
904 | void *lookup_baton) | |
905 | { | |
906 | struct macro_name_list new_no_loop; | |
907 | ||
908 | /* Create a new node to be added to the front of the no-expand list. | |
909 | This list is appropriate for re-scanning replacement lists, but | |
910 | it is *not* appropriate for scanning macro arguments; invocations | |
911 | of the macro whose arguments we are gathering *do* get expanded | |
912 | there. */ | |
913 | new_no_loop.name = id; | |
914 | new_no_loop.next = no_loop; | |
915 | ||
916 | /* What kind of macro are we expanding? */ | |
917 | if (def->kind == macro_object_like) | |
918 | { | |
919 | struct macro_buffer replacement_list; | |
920 | ||
921 | init_shared_buffer (&replacement_list, (char *) def->replacement, | |
922 | strlen (def->replacement)); | |
923 | ||
924 | scan (dest, &replacement_list, &new_no_loop, lookup_func, lookup_baton); | |
925 | return 1; | |
926 | } | |
927 | else if (def->kind == macro_function_like) | |
928 | { | |
929 | struct cleanup *back_to = make_cleanup (null_cleanup, 0); | |
0a029df5 | 930 | int argc = 0; |
a86bc61c | 931 | struct macro_buffer *argv = NULL; |
ec2bcbe7 JB |
932 | struct macro_buffer substituted; |
933 | struct macro_buffer substituted_src; | |
934 | ||
935 | if (def->argc >= 1 | |
a86bc61c | 936 | && strcmp (def->argv[def->argc - 1], "...") == 0) |
8a3fe4f8 | 937 | error (_("Varargs macros not implemented yet.")); |
ec2bcbe7 JB |
938 | |
939 | make_cleanup (free_current_contents, &argv); | |
940 | argv = gather_arguments (id, src, &argc); | |
941 | ||
942 | /* If we couldn't find any argument list, then we don't expand | |
943 | this macro. */ | |
944 | if (! argv) | |
945 | { | |
946 | do_cleanups (back_to); | |
947 | return 0; | |
948 | } | |
949 | ||
950 | /* Check that we're passing an acceptable number of arguments for | |
951 | this macro. */ | |
952 | if (argc != def->argc) | |
953 | { | |
954 | /* Remember that a sequence of tokens like "foo()" is a | |
955 | valid invocation of a macro expecting either zero or one | |
956 | arguments. */ | |
957 | if (! (argc == 1 | |
958 | && argv[0].len == 0 | |
959 | && def->argc == 0)) | |
8a3fe4f8 AC |
960 | error (_("Wrong number of arguments to macro `%s' " |
961 | "(expected %d, got %d)."), | |
ec2bcbe7 JB |
962 | id, def->argc, argc); |
963 | } | |
964 | ||
965 | /* Note that we don't expand macro invocations in the arguments | |
966 | yet --- we let subst_args take care of that. Parameters that | |
967 | appear as operands of the stringifying operator "#" or the | |
968 | splicing operator "##" don't get macro references expanded, | |
969 | so we can't really tell whether it's appropriate to macro- | |
970 | expand an argument until we see how it's being used. */ | |
971 | init_buffer (&substituted, 0); | |
972 | make_cleanup (cleanup_macro_buffer, &substituted); | |
973 | substitute_args (&substituted, def, argc, argv, no_loop, | |
974 | lookup_func, lookup_baton); | |
975 | ||
976 | /* Now `substituted' is the macro's replacement list, with all | |
977 | argument values substituted into it properly. Re-scan it for | |
978 | macro references, but don't expand invocations of this macro. | |
979 | ||
980 | We create a new buffer, `substituted_src', which points into | |
981 | `substituted', and scan that. We can't scan `substituted' | |
982 | itself, since the tokenization process moves the buffer's | |
983 | text pointer around, and we still need to be able to find | |
984 | `substituted's original text buffer after scanning it so we | |
985 | can free it. */ | |
986 | init_shared_buffer (&substituted_src, substituted.text, substituted.len); | |
987 | scan (dest, &substituted_src, &new_no_loop, lookup_func, lookup_baton); | |
988 | ||
989 | do_cleanups (back_to); | |
990 | ||
991 | return 1; | |
992 | } | |
993 | else | |
e2e0b3e5 | 994 | internal_error (__FILE__, __LINE__, _("bad macro definition kind")); |
ec2bcbe7 JB |
995 | } |
996 | ||
997 | ||
998 | /* If the single token in SRC_FIRST followed by the tokens in SRC_REST | |
999 | constitute a macro invokation not forbidden in NO_LOOP, append its | |
1000 | expansion to DEST and return non-zero. Otherwise, return zero, and | |
1001 | leave DEST unchanged. | |
1002 | ||
1003 | SRC_FIRST and SRC_REST must be shared buffers; DEST must not be one. | |
1004 | SRC_FIRST must be a string built by get_token. */ | |
1005 | static int | |
1006 | maybe_expand (struct macro_buffer *dest, | |
1007 | struct macro_buffer *src_first, | |
1008 | struct macro_buffer *src_rest, | |
1009 | struct macro_name_list *no_loop, | |
1010 | macro_lookup_ftype *lookup_func, | |
1011 | void *lookup_baton) | |
1012 | { | |
1013 | gdb_assert (src_first->shared); | |
1014 | gdb_assert (src_rest->shared); | |
1015 | gdb_assert (! dest->shared); | |
1016 | ||
1017 | /* Is this token an identifier? */ | |
1018 | if (src_first->is_identifier) | |
1019 | { | |
1020 | /* Make a null-terminated copy of it, since that's what our | |
1021 | lookup function expects. */ | |
1022 | char *id = xmalloc (src_first->len + 1); | |
1023 | struct cleanup *back_to = make_cleanup (xfree, id); | |
1024 | memcpy (id, src_first->text, src_first->len); | |
1025 | id[src_first->len] = 0; | |
1026 | ||
1027 | /* If we're currently re-scanning the result of expanding | |
1028 | this macro, don't expand it again. */ | |
1029 | if (! currently_rescanning (no_loop, id)) | |
1030 | { | |
1031 | /* Does this identifier have a macro definition in scope? */ | |
1032 | struct macro_definition *def = lookup_func (id, lookup_baton); | |
1033 | ||
1034 | if (def && expand (id, def, dest, src_rest, no_loop, | |
1035 | lookup_func, lookup_baton)) | |
1036 | { | |
1037 | do_cleanups (back_to); | |
1038 | return 1; | |
1039 | } | |
1040 | } | |
1041 | ||
1042 | do_cleanups (back_to); | |
1043 | } | |
1044 | ||
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | ||
1049 | /* Expand macro references in SRC, appending the results to DEST. | |
1050 | Assume we are re-scanning the result of expanding the macros named | |
1051 | in NO_LOOP, and don't try to re-expand references to them. | |
1052 | ||
1053 | SRC must be a shared buffer; DEST must not be one. */ | |
1054 | static void | |
1055 | scan (struct macro_buffer *dest, | |
1056 | struct macro_buffer *src, | |
1057 | struct macro_name_list *no_loop, | |
1058 | macro_lookup_ftype *lookup_func, | |
1059 | void *lookup_baton) | |
1060 | { | |
1061 | gdb_assert (src->shared); | |
1062 | gdb_assert (! dest->shared); | |
1063 | ||
1064 | for (;;) | |
1065 | { | |
1066 | struct macro_buffer tok; | |
1067 | char *original_src_start = src->text; | |
1068 | ||
1069 | /* Find the next token in SRC. */ | |
1070 | if (! get_token (&tok, src)) | |
1071 | break; | |
1072 | ||
1073 | /* Just for aesthetics. If we skipped some whitespace, copy | |
1074 | that to DEST. */ | |
1075 | if (tok.text > original_src_start) | |
1076 | { | |
1077 | appendmem (dest, original_src_start, tok.text - original_src_start); | |
1078 | dest->last_token = dest->len; | |
1079 | } | |
1080 | ||
1081 | if (! maybe_expand (dest, &tok, src, no_loop, lookup_func, lookup_baton)) | |
1082 | /* We didn't end up expanding tok as a macro reference, so | |
1083 | simply append it to dest. */ | |
1084 | append_tokens_without_splicing (dest, &tok); | |
1085 | } | |
1086 | ||
1087 | /* Just for aesthetics. If there was any trailing whitespace in | |
1088 | src, copy it to dest. */ | |
1089 | if (src->len) | |
1090 | { | |
1091 | appendmem (dest, src->text, src->len); | |
1092 | dest->last_token = dest->len; | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | ||
1097 | char * | |
1098 | macro_expand (const char *source, | |
1099 | macro_lookup_ftype *lookup_func, | |
1100 | void *lookup_func_baton) | |
1101 | { | |
1102 | struct macro_buffer src, dest; | |
1103 | struct cleanup *back_to; | |
1104 | ||
1105 | init_shared_buffer (&src, (char *) source, strlen (source)); | |
1106 | ||
1107 | init_buffer (&dest, 0); | |
1108 | dest.last_token = 0; | |
1109 | back_to = make_cleanup (cleanup_macro_buffer, &dest); | |
1110 | ||
1111 | scan (&dest, &src, 0, lookup_func, lookup_func_baton); | |
1112 | ||
1113 | appendc (&dest, '\0'); | |
1114 | ||
1115 | discard_cleanups (back_to); | |
1116 | return dest.text; | |
1117 | } | |
1118 | ||
1119 | ||
1120 | char * | |
1121 | macro_expand_once (const char *source, | |
1122 | macro_lookup_ftype *lookup_func, | |
1123 | void *lookup_func_baton) | |
1124 | { | |
8a3fe4f8 | 1125 | error (_("Expand-once not implemented yet.")); |
ec2bcbe7 JB |
1126 | } |
1127 | ||
1128 | ||
1129 | char * | |
1130 | macro_expand_next (char **lexptr, | |
1131 | macro_lookup_ftype *lookup_func, | |
1132 | void *lookup_baton) | |
1133 | { | |
1134 | struct macro_buffer src, dest, tok; | |
1135 | struct cleanup *back_to; | |
1136 | ||
1137 | /* Set up SRC to refer to the input text, pointed to by *lexptr. */ | |
1138 | init_shared_buffer (&src, *lexptr, strlen (*lexptr)); | |
1139 | ||
1140 | /* Set up DEST to receive the expansion, if there is one. */ | |
1141 | init_buffer (&dest, 0); | |
1142 | dest.last_token = 0; | |
1143 | back_to = make_cleanup (cleanup_macro_buffer, &dest); | |
1144 | ||
1145 | /* Get the text's first preprocessing token. */ | |
1146 | if (! get_token (&tok, &src)) | |
1147 | { | |
1148 | do_cleanups (back_to); | |
1149 | return 0; | |
1150 | } | |
1151 | ||
1152 | /* If it's a macro invocation, expand it. */ | |
1153 | if (maybe_expand (&dest, &tok, &src, 0, lookup_func, lookup_baton)) | |
1154 | { | |
1155 | /* It was a macro invocation! Package up the expansion as a | |
1156 | null-terminated string and return it. Set *lexptr to the | |
1157 | start of the next token in the input. */ | |
1158 | appendc (&dest, '\0'); | |
1159 | discard_cleanups (back_to); | |
1160 | *lexptr = src.text; | |
1161 | return dest.text; | |
1162 | } | |
1163 | else | |
1164 | { | |
1165 | /* It wasn't a macro invocation. */ | |
1166 | do_cleanups (back_to); | |
1167 | return 0; | |
1168 | } | |
1169 | } |