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b0699dad | 1 | /* Parse C expressions for cpplib. |
5d8ebbd8 NB |
2 | Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001, |
3 | 2002 Free Software Foundation. | |
e38992e8 | 4 | Contributed by Per Bothner, 1994. |
7f2935c7 PB |
5 | |
6 | This program is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 2, or (at your option) any | |
9 | later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
940d9d63 | 18 | Foundation, 59 Temple Place - Suite 330, |
e38992e8 | 19 | Boston, MA 02111-1307, USA. */ |
7f2935c7 | 20 | |
7f2935c7 | 21 | #include "config.h" |
b04cd507 | 22 | #include "system.h" |
487a6e06 | 23 | #include "cpplib.h" |
88ae23e7 | 24 | #include "cpphash.h" |
7f2935c7 | 25 | |
7f2935c7 PB |
26 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a |
27 | number with SUM's sign, where A, B, and SUM are all C integers. */ | |
28 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) | |
29 | ||
b04cd507 | 30 | static void integer_overflow PARAMS ((cpp_reader *)); |
b0699dad | 31 | static HOST_WIDEST_INT left_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT, |
e23c0ba3 ZW |
32 | unsigned int, |
33 | unsigned HOST_WIDEST_INT)); | |
b0699dad | 34 | static HOST_WIDEST_INT right_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT, |
e23c0ba3 ZW |
35 | unsigned int, |
36 | unsigned HOST_WIDEST_INT)); | |
cf00a885 | 37 | static struct op parse_number PARAMS ((cpp_reader *, const cpp_token *)); |
cf00a885 | 38 | static struct op parse_defined PARAMS ((cpp_reader *)); |
60284a59 | 39 | static struct op eval_token PARAMS ((cpp_reader *, const cpp_token *)); |
87ed109f | 40 | static struct op *reduce PARAMS ((cpp_reader *, struct op *, enum cpp_ttype)); |
cf00a885 ZW |
41 | |
42 | struct op | |
b0699dad | 43 | { |
cf00a885 | 44 | enum cpp_ttype op; |
562a5c27 | 45 | uchar unsignedp; /* True if value should be treated as unsigned. */ |
4063b943 | 46 | HOST_WIDEST_INT value; /* The value logically "right" of op. */ |
7f2935c7 | 47 | }; |
7f2935c7 | 48 | |
f8b954fc NB |
49 | /* Token type abuse. There is no "error" token, but we can't get |
50 | comments in #if, so we can abuse that token type. Similarly, | |
51 | create unary plus and minus operators. */ | |
cf00a885 | 52 | #define CPP_ERROR CPP_COMMENT |
f8b954fc NB |
53 | #define CPP_UPLUS (CPP_LAST_CPP_OP + 1) |
54 | #define CPP_UMINUS (CPP_LAST_CPP_OP + 2) | |
cf00a885 | 55 | |
15dad1d9 ZW |
56 | /* With -O2, gcc appears to produce nice code, moving the error |
57 | message load and subsequent jump completely out of the main path. */ | |
15dad1d9 | 58 | #define SYNTAX_ERROR(msgid) \ |
ebef4e8c | 59 | do { cpp_error (pfile, DL_ERROR, msgid); goto syntax_error; } while(0) |
15dad1d9 | 60 | #define SYNTAX_ERROR2(msgid, arg) \ |
ebef4e8c | 61 | do { cpp_error (pfile, DL_ERROR, msgid, arg); goto syntax_error; } while(0) |
15dad1d9 | 62 | |
cf00a885 ZW |
63 | struct suffix |
64 | { | |
8b60264b KG |
65 | const unsigned char s[4]; |
66 | const unsigned char u; | |
67 | const unsigned char l; | |
cf00a885 ZW |
68 | }; |
69 | ||
8b60264b | 70 | static const struct suffix vsuf_1[] = { |
cf00a885 ZW |
71 | { "u", 1, 0 }, { "U", 1, 0 }, |
72 | { "l", 0, 1 }, { "L", 0, 1 } | |
73 | }; | |
74 | ||
8b60264b | 75 | static const struct suffix vsuf_2[] = { |
cf00a885 ZW |
76 | { "ul", 1, 1 }, { "UL", 1, 1 }, { "uL", 1, 1 }, { "Ul", 1, 1 }, |
77 | { "lu", 1, 1 }, { "LU", 1, 1 }, { "Lu", 1, 1 }, { "lU", 1, 1 }, | |
78 | { "ll", 0, 2 }, { "LL", 0, 2 } | |
79 | }; | |
7f2935c7 | 80 | |
8b60264b | 81 | static const struct suffix vsuf_3[] = { |
cf00a885 ZW |
82 | { "ull", 1, 2 }, { "ULL", 1, 2 }, { "uLL", 1, 2 }, { "Ull", 1, 2 }, |
83 | { "llu", 1, 2 }, { "LLU", 1, 2 }, { "LLu", 1, 2 }, { "llU", 1, 2 } | |
84 | }; | |
cf00a885 | 85 | |
5d8ebbd8 NB |
86 | /* Parse and convert what is presumably an integer in TOK. Accepts |
87 | decimal, hex, or octal with or without size suffixes. Returned op | |
88 | is CPP_ERROR on error, otherwise it is a CPP_NUMBER. */ | |
cf00a885 ZW |
89 | static struct op |
90 | parse_number (pfile, tok) | |
7f2935c7 | 91 | cpp_reader *pfile; |
cf00a885 | 92 | const cpp_token *tok; |
7f2935c7 | 93 | { |
cf00a885 | 94 | struct op op; |
562a5c27 NB |
95 | const uchar *start = tok->val.str.text; |
96 | const uchar *end = start + tok->val.str.len; | |
97 | const uchar *p = start; | |
bfb9dc7f | 98 | int c = 0, i, nsuff; |
e915b770 | 99 | unsigned HOST_WIDEST_INT n = 0, nd, MAX_over_base; |
f13eb63a ZW |
100 | int base = 10; |
101 | int overflow = 0; | |
102 | int digit, largest_digit = 0; | |
cf00a885 | 103 | const struct suffix *sufftab; |
7f2935c7 PB |
104 | |
105 | op.unsignedp = 0; | |
106 | ||
f13eb63a ZW |
107 | if (p[0] == '0') |
108 | { | |
109 | if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X')) | |
110 | { | |
111 | p += 2; | |
112 | base = 16; | |
113 | } | |
114 | else | |
115 | { | |
116 | p += 1; | |
117 | base = 8; | |
118 | } | |
7f2935c7 PB |
119 | } |
120 | ||
0f41302f | 121 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
e915b770 KG |
122 | MAX_over_base = (((unsigned HOST_WIDEST_INT) -1) |
123 | / ((unsigned HOST_WIDEST_INT) base)); | |
7f2935c7 | 124 | |
cf00a885 | 125 | for(; p < end; p++) |
f13eb63a | 126 | { |
cf00a885 | 127 | c = *p; |
f13eb63a | 128 | |
9e1ac915 KG |
129 | if (ISDIGIT (c) |
130 | || (base == 16 && ISXDIGIT (c))) | |
131 | digit = hex_value (c); | |
f13eb63a | 132 | else |
cf00a885 ZW |
133 | break; |
134 | ||
f13eb63a ZW |
135 | if (largest_digit < digit) |
136 | largest_digit = digit; | |
137 | nd = n * base + digit; | |
138 | overflow |= MAX_over_base < n || nd < n; | |
139 | n = nd; | |
7f2935c7 | 140 | } |
7f2935c7 | 141 | |
cf00a885 | 142 | if (p < end) |
f13eb63a | 143 | { |
cf00a885 ZW |
144 | /* Check for a floating point constant. Note that float constants |
145 | with an exponent or suffix but no decimal point are technically | |
5ef865d5 | 146 | invalid (C99 6.4.4.2) but accepted elsewhere. */ |
cf00a885 ZW |
147 | if ((c == '.' || c == 'F' || c == 'f') |
148 | || (base == 10 && (c == 'E' || c == 'e') | |
149 | && p+1 < end && (p[1] == '+' || p[1] == '-')) | |
150 | || (base == 16 && (c == 'P' || c == 'p') | |
151 | && p+1 < end && (p[1] == '+' || p[1] == '-'))) | |
152 | SYNTAX_ERROR ("floating point numbers are not valid in #if"); | |
153 | ||
154 | /* Determine the suffix. l means long, and u means unsigned. | |
155 | See the suffix tables, above. */ | |
156 | switch (end - p) | |
157 | { | |
ca7558fc KG |
158 | case 1: sufftab = vsuf_1; nsuff = ARRAY_SIZE (vsuf_1); break; |
159 | case 2: sufftab = vsuf_2; nsuff = ARRAY_SIZE (vsuf_2); break; | |
160 | case 3: sufftab = vsuf_3; nsuff = ARRAY_SIZE (vsuf_3); break; | |
cf00a885 ZW |
161 | default: goto invalid_suffix; |
162 | } | |
163 | ||
164 | for (i = 0; i < nsuff; i++) | |
165 | if (memcmp (p, sufftab[i].s, end - p) == 0) | |
166 | break; | |
167 | if (i == nsuff) | |
168 | goto invalid_suffix; | |
169 | op.unsignedp = sufftab[i].u; | |
170 | ||
7065e130 NB |
171 | if (CPP_WTRADITIONAL (pfile) |
172 | && sufftab[i].u | |
c691145a | 173 | && ! cpp_sys_macro_p (pfile)) |
ebef4e8c | 174 | cpp_error (pfile, DL_WARNING, "traditional C rejects the `U' suffix"); |
fef1de5d NB |
175 | if (sufftab[i].l == 2 && CPP_OPTION (pfile, pedantic) |
176 | && ! CPP_OPTION (pfile, c99)) | |
ebef4e8c NB |
177 | cpp_error (pfile, DL_PEDWARN, |
178 | "too many 'l' suffixes in integer constant"); | |
f13eb63a ZW |
179 | } |
180 | ||
7f2935c7 | 181 | if (base <= largest_digit) |
ebef4e8c NB |
182 | cpp_error (pfile, DL_PEDWARN, |
183 | "integer constant contains digits beyond the radix"); | |
7f2935c7 PB |
184 | |
185 | if (overflow) | |
ebef4e8c | 186 | cpp_error (pfile, DL_PEDWARN, "integer constant out of range"); |
7f2935c7 PB |
187 | |
188 | /* If too big to be signed, consider it unsigned. */ | |
e915b770 | 189 | else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp) |
7f2935c7 PB |
190 | { |
191 | if (base == 10) | |
ebef4e8c NB |
192 | cpp_error (pfile, DL_WARNING, |
193 | "integer constant is so large that it is unsigned"); | |
7f2935c7 PB |
194 | op.unsignedp = 1; |
195 | } | |
196 | ||
197 | op.value = n; | |
c60e94a7 | 198 | op.op = CPP_NUMBER; |
7f2935c7 | 199 | return op; |
f13eb63a | 200 | |
cf00a885 | 201 | invalid_suffix: |
ebef4e8c | 202 | cpp_error (pfile, DL_ERROR, "invalid suffix '%.*s' on integer constant", |
cf00a885 ZW |
203 | (int) (end - p), p); |
204 | syntax_error: | |
205 | op.op = CPP_ERROR; | |
f13eb63a | 206 | return op; |
7f2935c7 PB |
207 | } |
208 | ||
5d8ebbd8 | 209 | /* Handle meeting "defined" in a preprocessor expression. */ |
cf00a885 | 210 | static struct op |
ba412f14 ZW |
211 | parse_defined (pfile) |
212 | cpp_reader *pfile; | |
213 | { | |
93c80368 NB |
214 | int paren = 0; |
215 | cpp_hashnode *node = 0; | |
4ed5bcfb | 216 | const cpp_token *token; |
cf00a885 | 217 | struct op op; |
63d75005 | 218 | cpp_context *initial_context = pfile->context; |
ba412f14 | 219 | |
93c80368 NB |
220 | /* Don't expand macros. */ |
221 | pfile->state.prevent_expansion++; | |
222 | ||
4ed5bcfb NB |
223 | token = cpp_get_token (pfile); |
224 | if (token->type == CPP_OPEN_PAREN) | |
ba412f14 | 225 | { |
cf00a885 | 226 | paren = 1; |
4ed5bcfb | 227 | token = cpp_get_token (pfile); |
ba412f14 ZW |
228 | } |
229 | ||
4ed5bcfb | 230 | if (token->type == CPP_NAME) |
93c80368 | 231 | { |
4ed5bcfb NB |
232 | node = token->val.node; |
233 | if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN) | |
93c80368 | 234 | { |
ebef4e8c | 235 | cpp_error (pfile, DL_ERROR, "missing ')' after \"defined\""); |
4ed5bcfb | 236 | node = 0; |
93c80368 NB |
237 | } |
238 | } | |
239 | else | |
3c8465d0 | 240 | { |
ebef4e8c NB |
241 | cpp_error (pfile, DL_ERROR, |
242 | "operator \"defined\" requires an identifier"); | |
4ed5bcfb | 243 | if (token->flags & NAMED_OP) |
3c8465d0 NB |
244 | { |
245 | cpp_token op; | |
246 | ||
247 | op.flags = 0; | |
4ed5bcfb | 248 | op.type = token->type; |
ebef4e8c | 249 | cpp_error (pfile, DL_ERROR, |
3c8465d0 | 250 | "(\"%s\" is an alternative token for \"%s\" in C++)", |
4ed5bcfb | 251 | cpp_token_as_text (pfile, token), |
3c8465d0 NB |
252 | cpp_token_as_text (pfile, &op)); |
253 | } | |
254 | } | |
15dad1d9 | 255 | |
93c80368 NB |
256 | if (!node) |
257 | op.op = CPP_ERROR; | |
258 | else | |
15dad1d9 | 259 | { |
63d75005 | 260 | if (pfile->context != initial_context) |
ebef4e8c NB |
261 | cpp_error (pfile, DL_WARNING, |
262 | "this use of \"defined\" may not be portable"); | |
63d75005 | 263 | |
93c80368 | 264 | op.value = node->type == NT_MACRO; |
cf00a885 | 265 | op.unsignedp = 0; |
c60e94a7 | 266 | op.op = CPP_NUMBER; |
15dad1d9 | 267 | |
6d18adbc NB |
268 | /* A possible controlling macro of the form #if !defined (). |
269 | _cpp_parse_expr checks there was no other junk on the line. */ | |
270 | pfile->mi_ind_cmacro = node; | |
15dad1d9 | 271 | } |
93c80368 NB |
272 | |
273 | pfile->state.prevent_expansion--; | |
15dad1d9 | 274 | return op; |
15dad1d9 ZW |
275 | } |
276 | ||
60284a59 NB |
277 | /* Convert a token into a CPP_NUMBER (an interpreted preprocessing |
278 | number or character constant, or the result of the "defined" or "#" | |
279 | operators), or CPP_ERROR on error. */ | |
cf00a885 | 280 | static struct op |
60284a59 | 281 | eval_token (pfile, token) |
52529158 | 282 | cpp_reader *pfile; |
60284a59 | 283 | const cpp_token *token; |
7f2935c7 | 284 | { |
60284a59 | 285 | unsigned int temp; |
cf00a885 | 286 | struct op op; |
60284a59 NB |
287 | |
288 | op.op = CPP_NUMBER; | |
289 | op.unsignedp = 0; | |
041c3194 | 290 | |
93c80368 | 291 | switch (token->type) |
ba412f14 | 292 | { |
7f2935c7 | 293 | case CPP_NUMBER: |
93c80368 | 294 | return parse_number (pfile, token); |
7f2f1a66 | 295 | |
cf00a885 | 296 | case CPP_WCHAR: |
60284a59 NB |
297 | op.unsignedp = WCHAR_UNSIGNED; |
298 | case CPP_CHAR: /* Always unsigned. */ | |
299 | op.value = cpp_interpret_charconst (pfile, token, 1, &temp); | |
300 | break; | |
ba412f14 | 301 | |
92936ecf | 302 | case CPP_NAME: |
93c80368 | 303 | if (token->val.node == pfile->spec_nodes.n_defined) |
63d75005 | 304 | return parse_defined (pfile); |
7d4918a2 ZW |
305 | else if (CPP_OPTION (pfile, cplusplus) |
306 | && (token->val.node == pfile->spec_nodes.n_true | |
307 | || token->val.node == pfile->spec_nodes.n_false)) | |
308 | { | |
7d4918a2 ZW |
309 | op.value = (token->val.node == pfile->spec_nodes.n_true); |
310 | ||
311 | /* Warn about use of true or false in #if when pedantic | |
312 | and stdbool.h has not been included. */ | |
313 | if (CPP_PEDANTIC (pfile) | |
314 | && ! cpp_defined (pfile, DSC("__bool_true_false_are_defined"))) | |
ebef4e8c NB |
315 | cpp_error (pfile, DL_PEDWARN, |
316 | "ISO C++ does not permit \"%s\" in #if", | |
317 | NODE_NAME (token->val.node)); | |
7d4918a2 ZW |
318 | } |
319 | else | |
320 | { | |
7d4918a2 | 321 | op.value = 0; |
87ed109f | 322 | if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval) |
ebef4e8c NB |
323 | cpp_error (pfile, DL_WARNING, "\"%s\" is not defined", |
324 | NODE_NAME (token->val.node)); | |
7f2935c7 | 325 | } |
60284a59 | 326 | break; |
7f2935c7 | 327 | |
60284a59 NB |
328 | default: /* CPP_HASH */ |
329 | if (_cpp_test_assertion (pfile, &temp)) | |
330 | op.op = CPP_ERROR; | |
331 | op.value = temp; | |
93c80368 | 332 | } |
7c3bb1de | 333 | |
cf00a885 | 334 | return op; |
7c3bb1de | 335 | } |
7f2935c7 | 336 | |
5d8ebbd8 | 337 | /* Warn if appropriate on overflow. */ |
7f2935c7 PB |
338 | static void |
339 | integer_overflow (pfile) | |
340 | cpp_reader *pfile; | |
341 | { | |
342 | if (CPP_PEDANTIC (pfile)) | |
ebef4e8c NB |
343 | cpp_error (pfile, DL_PEDWARN, |
344 | "integer overflow in preprocessor expression"); | |
7f2935c7 PB |
345 | } |
346 | ||
5d8ebbd8 NB |
347 | /* Handle shifting A left by B bits. UNSIGNEDP is non-zero if A is |
348 | unsigned. */ | |
ca261cb4 | 349 | static HOST_WIDEST_INT |
7f2935c7 PB |
350 | left_shift (pfile, a, unsignedp, b) |
351 | cpp_reader *pfile; | |
ca261cb4 | 352 | HOST_WIDEST_INT a; |
e23c0ba3 | 353 | unsigned int unsignedp; |
ca261cb4 | 354 | unsigned HOST_WIDEST_INT b; |
7f2935c7 | 355 | { |
ca261cb4 | 356 | if (b >= HOST_BITS_PER_WIDEST_INT) |
7f2935c7 PB |
357 | { |
358 | if (! unsignedp && a != 0) | |
359 | integer_overflow (pfile); | |
360 | return 0; | |
361 | } | |
362 | else if (unsignedp) | |
ca261cb4 | 363 | return (unsigned HOST_WIDEST_INT) a << b; |
7f2935c7 PB |
364 | else |
365 | { | |
ca261cb4 | 366 | HOST_WIDEST_INT l = a << b; |
7f2935c7 PB |
367 | if (l >> b != a) |
368 | integer_overflow (pfile); | |
369 | return l; | |
370 | } | |
371 | } | |
372 | ||
5d8ebbd8 NB |
373 | /* Handle shifting A right by B bits. UNSIGNEDP is non-zero if A is |
374 | unsigned. */ | |
ca261cb4 | 375 | static HOST_WIDEST_INT |
7f2935c7 | 376 | right_shift (pfile, a, unsignedp, b) |
d6f4ec51 | 377 | cpp_reader *pfile ATTRIBUTE_UNUSED; |
ca261cb4 | 378 | HOST_WIDEST_INT a; |
e23c0ba3 | 379 | unsigned int unsignedp; |
ca261cb4 | 380 | unsigned HOST_WIDEST_INT b; |
7f2935c7 | 381 | { |
ca261cb4 KG |
382 | if (b >= HOST_BITS_PER_WIDEST_INT) |
383 | return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1); | |
7f2935c7 | 384 | else if (unsignedp) |
ca261cb4 | 385 | return (unsigned HOST_WIDEST_INT) a >> b; |
7f2935c7 PB |
386 | else |
387 | return a >> b; | |
388 | } | |
389 | \f | |
4063b943 | 390 | /* Operator precedence and flags table. |
dbac4aff NB |
391 | |
392 | After an operator is returned from the lexer, if it has priority less | |
87ed109f NB |
393 | than the operator on the top of the stack, we reduce the stack by one |
394 | operator and repeat the test. Since equal priorities do not reduce, | |
395 | this is naturally right-associative. | |
396 | ||
397 | We handle left-associative operators by decrementing the priority of | |
398 | just-lexed operators by one, but retaining the priority of operators | |
399 | already on the stack. | |
dbac4aff NB |
400 | |
401 | The remaining cases are '(' and ')'. We handle '(' by skipping the | |
402 | reduction phase completely. ')' is given lower priority than | |
403 | everything else, including '(', effectively forcing a reduction of the | |
87ed109f NB |
404 | parenthesised expression. If there is a matching '(', the routine |
405 | reduce() exits immediately. If the normal exit route sees a ')', then | |
406 | there cannot have been a matching '(' and an error message is output. | |
4063b943 | 407 | |
f8b954fc NB |
408 | The parser assumes all shifted operators require a left operand unless |
409 | the flag NO_L_OPERAND is set. These semantics are automatic; any | |
410 | extra semantics need to be handled with operator-specific code. */ | |
4063b943 | 411 | |
4063b943 | 412 | /* Flags. */ |
87ed109f NB |
413 | #define NO_L_OPERAND (1 << 0) |
414 | #define LEFT_ASSOC (1 << 1) | |
eba30526 | 415 | |
cf00a885 ZW |
416 | /* Operator to priority map. Must be in the same order as the first |
417 | N entries of enum cpp_ttype. */ | |
87ed109f NB |
418 | static const struct operator |
419 | { | |
60284a59 | 420 | uchar prio; |
87ed109f NB |
421 | uchar flags; |
422 | } optab[] = | |
cf00a885 | 423 | { |
87ed109f NB |
424 | /* EQ */ {0, 0}, /* Shouldn't happen. */ |
425 | /* NOT */ {16, NO_L_OPERAND}, | |
426 | /* GREATER */ {12, LEFT_ASSOC}, | |
427 | /* LESS */ {12, LEFT_ASSOC}, | |
428 | /* PLUS */ {14, LEFT_ASSOC}, | |
429 | /* MINUS */ {14, LEFT_ASSOC}, | |
430 | /* MULT */ {15, LEFT_ASSOC}, | |
431 | /* DIV */ {15, LEFT_ASSOC}, | |
432 | /* MOD */ {15, LEFT_ASSOC}, | |
433 | /* AND */ {9, LEFT_ASSOC}, | |
434 | /* OR */ {7, LEFT_ASSOC}, | |
435 | /* XOR */ {8, LEFT_ASSOC}, | |
436 | /* RSHIFT */ {13, LEFT_ASSOC}, | |
437 | /* LSHIFT */ {13, LEFT_ASSOC}, | |
438 | /* MIN */ {10, LEFT_ASSOC}, /* C++ specific */ | |
439 | /* MAX */ {10, LEFT_ASSOC}, /* extensions */ | |
440 | ||
441 | /* COMPL */ {16, NO_L_OPERAND}, | |
442 | /* AND_AND */ {6, LEFT_ASSOC}, | |
443 | /* OR_OR */ {5, LEFT_ASSOC}, | |
444 | /* QUERY */ {3, 0}, | |
445 | /* COLON */ {4, LEFT_ASSOC}, | |
446 | /* COMMA */ {2, LEFT_ASSOC}, | |
447 | /* OPEN_PAREN */ {1, NO_L_OPERAND}, | |
448 | /* CLOSE_PAREN */ {0, 0}, | |
449 | /* EOF */ {0, 0}, | |
450 | /* EQ_EQ */ {11, LEFT_ASSOC}, | |
451 | /* NOT_EQ */ {11, LEFT_ASSOC}, | |
452 | /* GREATER_EQ */ {12, LEFT_ASSOC}, | |
453 | /* LESS_EQ */ {12, LEFT_ASSOC}, | |
454 | /* UPLUS */ {16, NO_L_OPERAND}, | |
455 | /* UMINUS */ {16, NO_L_OPERAND} | |
cf00a885 ZW |
456 | }; |
457 | ||
7f2935c7 | 458 | #define COMPARE(OP) \ |
4063b943 | 459 | top->unsignedp = 0; \ |
b22ef131 | 460 | top->value = (unsigned1 | unsigned2) \ |
4063b943 NB |
461 | ? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 \ |
462 | : (v1 OP v2) | |
463 | #define EQUALITY(OP) \ | |
464 | top->value = v1 OP v2; \ | |
465 | top->unsignedp = 0; | |
cf00a885 | 466 | #define BITWISE(OP) \ |
4063b943 | 467 | top->value = v1 OP v2; \ |
b22ef131 | 468 | top->unsignedp = unsigned1 | unsigned2; |
92936ecf ZW |
469 | #define MINMAX(OP) \ |
470 | top->value = (v1 OP v2) ? v1 : v2; \ | |
471 | top->unsignedp = unsigned1 | unsigned2; | |
cf00a885 ZW |
472 | #define UNARY(OP) \ |
473 | top->value = OP v2; \ | |
f8b954fc | 474 | top->unsignedp = unsigned2; |
cf00a885 | 475 | #define SHIFT(PSH, MSH) \ |
87ed109f | 476 | if (pfile->state.skip_eval) \ |
cf00a885 ZW |
477 | break; \ |
478 | top->unsignedp = unsigned1; \ | |
479 | if (v2 < 0 && ! unsigned2) \ | |
480 | top->value = MSH (pfile, v1, unsigned1, -v2); \ | |
481 | else \ | |
482 | top->value = PSH (pfile, v1, unsigned1, v2); | |
b22ef131 | 483 | |
7f2935c7 | 484 | /* Parse and evaluate a C expression, reading from PFILE. |
87ed109f NB |
485 | Returns the truth value of the expression. |
486 | ||
487 | The implementation is an operator precedence parser, i.e. a | |
488 | bottom-up parser, using a stack for not-yet-reduced tokens. | |
489 | ||
490 | The stack base is op_stack, and the current stack pointer is 'top'. | |
491 | There is a stack element for each operator (only), and the most | |
492 | recently pushed operator is 'top->op'. An operand (value) is | |
493 | stored in the 'value' field of the stack element of the operator | |
494 | that precedes it. */ | |
495 | bool | |
b0699dad | 496 | _cpp_parse_expr (pfile) |
7f2935c7 PB |
497 | cpp_reader *pfile; |
498 | { | |
87ed109f | 499 | struct op *top = pfile->op_stack; |
60284a59 | 500 | const cpp_token *token = NULL, *prev_token; |
87ed109f NB |
501 | unsigned int lex_count; |
502 | bool saw_leading_not, want_value = true; | |
503 | ||
504 | pfile->state.skip_eval = 0; | |
7f2935c7 | 505 | |
93c80368 | 506 | /* Set up detection of #if ! defined(). */ |
6d18adbc | 507 | pfile->mi_ind_cmacro = 0; |
87ed109f | 508 | saw_leading_not = false; |
6d18adbc | 509 | lex_count = 0; |
93c80368 | 510 | |
87ed109f | 511 | /* Lowest priority operator prevents further reductions. */ |
cf00a885 | 512 | top->op = CPP_EOF; |
4063b943 | 513 | |
7f2935c7 PB |
514 | for (;;) |
515 | { | |
cf00a885 | 516 | struct op op; |
7f2935c7 | 517 | |
60284a59 NB |
518 | prev_token = token; |
519 | token = cpp_get_token (pfile); | |
6d18adbc | 520 | lex_count++; |
60284a59 | 521 | op.op = token->type; |
7f2935c7 | 522 | |
7f2935c7 PB |
523 | switch (op.op) |
524 | { | |
60284a59 | 525 | /* These tokens convert into values. */ |
c60e94a7 | 526 | case CPP_NUMBER: |
60284a59 NB |
527 | case CPP_CHAR: |
528 | case CPP_WCHAR: | |
529 | case CPP_NAME: | |
530 | case CPP_HASH: | |
f8b954fc | 531 | if (!want_value) |
60284a59 NB |
532 | SYNTAX_ERROR2 ("missing binary operator before token \"%s\"", |
533 | cpp_token_as_text (pfile, token)); | |
f8b954fc | 534 | want_value = false; |
60284a59 NB |
535 | op = eval_token (pfile, token); |
536 | if (op.op == CPP_ERROR) | |
537 | goto syntax_error; | |
9ee70313 NB |
538 | top->value = op.value; |
539 | top->unsignedp = op.unsignedp; | |
9ee70313 NB |
540 | continue; |
541 | ||
6d18adbc NB |
542 | case CPP_NOT: |
543 | saw_leading_not = lex_count == 1; | |
6d18adbc | 544 | break; |
cf00a885 | 545 | case CPP_PLUS: |
f8b954fc NB |
546 | if (want_value) |
547 | op.op = CPP_UPLUS; | |
548 | break; | |
549 | case CPP_MINUS: | |
550 | if (want_value) | |
551 | op.op = CPP_UMINUS; | |
552 | break; | |
60284a59 NB |
553 | case CPP_OTHER: |
554 | if (ISGRAPH (token->val.c)) | |
555 | SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c); | |
556 | else | |
557 | SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c); | |
558 | ||
f8b954fc | 559 | default: |
60284a59 NB |
560 | if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ) |
561 | SYNTAX_ERROR2 ("token \"%s\" is not valid in #if expressions", | |
562 | cpp_token_as_text (pfile, token)); | |
f8b954fc | 563 | break; |
7f2935c7 | 564 | } |
7f2935c7 | 565 | |
87ed109f NB |
566 | /* Check we have a value or operator as appropriate. */ |
567 | if (optab[op.op].flags & NO_L_OPERAND) | |
7f2935c7 | 568 | { |
87ed109f | 569 | if (!want_value) |
60284a59 NB |
570 | SYNTAX_ERROR2 ("missing binary operator before token \"%s\"", |
571 | cpp_token_as_text (pfile, token)); | |
87ed109f NB |
572 | } |
573 | else if (want_value) | |
574 | { | |
60284a59 NB |
575 | /* Ordering here is subtle and intended to favour the |
576 | missing parenthesis diagnostics over alternatives. */ | |
87ed109f | 577 | if (op.op == CPP_CLOSE_PAREN) |
7f2935c7 | 578 | { |
cf00a885 | 579 | if (top->op == CPP_OPEN_PAREN) |
b22ef131 | 580 | SYNTAX_ERROR ("void expression between '(' and ')'"); |
7f2935c7 | 581 | } |
87ed109f NB |
582 | else if (top->op == CPP_EOF) |
583 | SYNTAX_ERROR ("#if with no expression"); | |
584 | if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN) | |
585 | SYNTAX_ERROR2 ("operator '%s' has no right operand", | |
60284a59 | 586 | cpp_token_as_text (pfile, prev_token)); |
7f2935c7 | 587 | } |
9ee70313 | 588 | |
87ed109f NB |
589 | top = reduce (pfile, top, op.op); |
590 | if (!top) | |
591 | goto syntax_error; | |
9ee70313 | 592 | |
60284a59 NB |
593 | if (op.op == CPP_EOF) |
594 | break; | |
595 | ||
87ed109f | 596 | switch (op.op) |
b22ef131 | 597 | { |
87ed109f NB |
598 | case CPP_CLOSE_PAREN: |
599 | continue; | |
87ed109f NB |
600 | case CPP_OR_OR: |
601 | if (top->value) | |
602 | pfile->state.skip_eval++; | |
603 | break; | |
604 | case CPP_AND_AND: | |
605 | case CPP_QUERY: | |
606 | if (!top->value) | |
607 | pfile->state.skip_eval++; | |
608 | break; | |
609 | case CPP_COLON: | |
60284a59 NB |
610 | if (top->op != CPP_QUERY) |
611 | SYNTAX_ERROR (" ':' without preceding '?'"); | |
87ed109f NB |
612 | if (top[-1].value) /* Was '?' condition true? */ |
613 | pfile->state.skip_eval++; | |
614 | else | |
615 | pfile->state.skip_eval--; | |
616 | default: | |
617 | break; | |
4063b943 | 618 | } |
87ed109f | 619 | |
f8b954fc | 620 | want_value = true; |
4063b943 | 621 | |
0f41302f | 622 | /* Check for and handle stack overflow. */ |
87ed109f NB |
623 | if (++top == pfile->op_limit) |
624 | top = _cpp_expand_op_stack (pfile); | |
7f2935c7 | 625 | |
7f2935c7 PB |
626 | top->op = op.op; |
627 | } | |
9ee70313 | 628 | |
6d18adbc NB |
629 | /* The controlling macro expression is only valid if we called lex 3 |
630 | times: <!> <defined expression> and <EOF>. push_conditional () | |
631 | checks that we are at top-of-file. */ | |
632 | if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3)) | |
633 | pfile->mi_ind_cmacro = 0; | |
634 | ||
87ed109f | 635 | if (top != pfile->op_stack) |
ebef4e8c NB |
636 | { |
637 | cpp_error (pfile, DL_ICE, "unbalanced stack in #if"); | |
4063b943 | 638 | syntax_error: |
87ed109f | 639 | return false; /* Return false on syntax error. */ |
4063b943 | 640 | } |
9ee70313 | 641 | |
87ed109f NB |
642 | return top->value != 0; |
643 | } | |
644 | ||
645 | /* Reduce the operator / value stack if possible, in preparation for | |
646 | pushing operator OP. Returns NULL on error, otherwise the top of | |
647 | the stack. */ | |
648 | static struct op * | |
649 | reduce (pfile, top, op) | |
650 | cpp_reader *pfile; | |
651 | struct op *top; | |
652 | enum cpp_ttype op; | |
653 | { | |
654 | unsigned int prio; | |
655 | ||
656 | if (op == CPP_OPEN_PAREN) | |
657 | return top; | |
658 | ||
659 | /* Decrement the priority of left-associative operators to force a | |
660 | reduction with operators of otherwise equal priority. */ | |
661 | prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0); | |
662 | while (prio < optab[top->op].prio) | |
663 | { | |
664 | HOST_WIDEST_INT v1, v2; | |
665 | unsigned int unsigned1, unsigned2; | |
666 | ||
667 | unsigned2 = top->unsignedp, v2 = top->value; | |
668 | top--; | |
669 | unsigned1 = top->unsignedp, v1 = top->value; | |
670 | ||
671 | /* Now set top->value = (top[1].op)(v1, v2); */ | |
672 | switch (top[1].op) | |
673 | { | |
674 | default: | |
60284a59 | 675 | cpp_error (pfile, DL_ICE, "impossible operator '%u'", top[1].op); |
87ed109f NB |
676 | return 0; |
677 | ||
678 | case CPP_NOT: UNARY(!); break; | |
679 | case CPP_COMPL: UNARY(~); break; | |
680 | case CPP_LESS: COMPARE(<); break; | |
681 | case CPP_GREATER: COMPARE(>); break; | |
682 | case CPP_LESS_EQ: COMPARE(<=); break; | |
683 | case CPP_GREATER_EQ: COMPARE(>=); break; | |
684 | case CPP_EQ_EQ: EQUALITY(==); break; | |
685 | case CPP_NOT_EQ: EQUALITY(!=); break; | |
686 | case CPP_AND: BITWISE(&); break; | |
687 | case CPP_XOR: BITWISE(^); break; | |
688 | case CPP_OR: BITWISE(|); break; | |
689 | case CPP_LSHIFT: SHIFT(left_shift, right_shift); break; | |
690 | case CPP_RSHIFT: SHIFT(right_shift, left_shift); break; | |
691 | case CPP_MIN: MINMAX(<); break; | |
692 | case CPP_MAX: MINMAX(>); break; | |
693 | ||
694 | case CPP_UPLUS: | |
695 | /* Can't use UNARY(+) because K+R C did not have unary | |
696 | plus. Can't use UNARY() because some compilers object | |
697 | to the empty argument. */ | |
698 | top->value = v2; | |
699 | top->unsignedp = unsigned2; | |
700 | if (CPP_WTRADITIONAL (pfile)) | |
701 | cpp_error (pfile, DL_WARNING, | |
702 | "traditional C rejects the unary plus operator"); | |
703 | break; | |
704 | case CPP_UMINUS: | |
705 | UNARY(-); | |
706 | if (!pfile->state.skip_eval && (top->value & v2) < 0 && !unsigned2) | |
707 | integer_overflow (pfile); | |
708 | break; | |
709 | ||
710 | case CPP_PLUS: | |
711 | top->value = v1 + v2; | |
712 | top->unsignedp = unsigned1 | unsigned2; | |
713 | if (! top->unsignedp && ! pfile->state.skip_eval | |
714 | && ! possible_sum_sign (v1, v2, top->value)) | |
715 | integer_overflow (pfile); | |
716 | break; | |
717 | case CPP_MINUS: | |
718 | top->value = v1 - v2; | |
719 | top->unsignedp = unsigned1 | unsigned2; | |
720 | if (! top->unsignedp && ! pfile->state.skip_eval | |
721 | && ! possible_sum_sign (top->value, v2, v1)) | |
722 | integer_overflow (pfile); | |
723 | break; | |
724 | case CPP_MULT: | |
725 | top->unsignedp = unsigned1 | unsigned2; | |
726 | if (top->unsignedp) | |
727 | top->value = (unsigned HOST_WIDEST_INT) v1 * v2; | |
728 | else if (!pfile->state.skip_eval) | |
729 | { | |
730 | top->value = v1 * v2; | |
731 | if (v1 && (top->value / v1 != v2 | |
732 | || (top->value & v1 & v2) < 0)) | |
733 | integer_overflow (pfile); | |
734 | } | |
735 | break; | |
736 | case CPP_DIV: | |
737 | case CPP_MOD: | |
738 | if (pfile->state.skip_eval) | |
739 | break; | |
740 | if (v2 == 0) | |
741 | { | |
742 | cpp_error (pfile, DL_ERROR, "division by zero in #if"); | |
743 | return 0; | |
744 | } | |
745 | top->unsignedp = unsigned1 | unsigned2; | |
746 | if (top[1].op == CPP_DIV) | |
747 | { | |
748 | if (top->unsignedp) | |
749 | top->value = (unsigned HOST_WIDEST_INT) v1 / v2; | |
750 | else | |
751 | { | |
752 | top->value = v1 / v2; | |
753 | if ((top->value & v1 & v2) < 0) | |
754 | integer_overflow (pfile); | |
755 | } | |
756 | } | |
757 | else | |
758 | { | |
759 | if (top->unsignedp) | |
760 | top->value = (unsigned HOST_WIDEST_INT) v1 % v2; | |
761 | else | |
762 | top->value = v1 % v2; | |
763 | } | |
764 | break; | |
765 | ||
766 | case CPP_OR_OR: | |
767 | top->value = v1 || v2; | |
768 | top->unsignedp = 0; | |
769 | if (v1) pfile->state.skip_eval--; | |
770 | break; | |
771 | case CPP_AND_AND: | |
772 | top->value = v1 && v2; | |
773 | top->unsignedp = 0; | |
774 | if (!v1) pfile->state.skip_eval--; | |
775 | break; | |
776 | case CPP_COMMA: | |
777 | if (CPP_PEDANTIC (pfile)) | |
778 | cpp_error (pfile, DL_PEDWARN, | |
779 | "comma operator in operand of #if"); | |
780 | top->value = v2; | |
781 | top->unsignedp = unsigned2; | |
782 | break; | |
783 | case CPP_QUERY: | |
784 | cpp_error (pfile, DL_ERROR, "'?' without following ':'"); | |
785 | return 0; | |
786 | case CPP_COLON: | |
87ed109f NB |
787 | top--; |
788 | if (top->value) pfile->state.skip_eval--; | |
789 | top->value = top->value ? v1 : v2; | |
790 | top->unsignedp = unsigned1 | unsigned2; | |
791 | break; | |
792 | case CPP_OPEN_PAREN: | |
793 | if (op != CPP_CLOSE_PAREN) | |
794 | { | |
795 | cpp_error (pfile, DL_ERROR, "missing ')' in expression"); | |
796 | return 0; | |
797 | } | |
798 | top->value = v2; | |
799 | top->unsignedp = unsigned2; | |
800 | return top; | |
801 | } | |
802 | } | |
803 | ||
804 | if (op == CPP_CLOSE_PAREN) | |
805 | { | |
806 | cpp_error (pfile, DL_ERROR, "missing '(' in expression"); | |
807 | return 0; | |
808 | } | |
809 | ||
810 | return top; | |
811 | } | |
812 | ||
813 | /* Returns the position of the old top of stack after expansion. */ | |
814 | struct op * | |
815 | _cpp_expand_op_stack (pfile) | |
816 | cpp_reader *pfile; | |
817 | { | |
818 | size_t n = (size_t) (pfile->op_limit - pfile->op_stack); | |
819 | ||
820 | pfile->op_stack = (struct op *) xrealloc (pfile->op_stack, | |
821 | (n * 2 + 20) * sizeof (struct op)); | |
822 | ||
823 | return pfile->op_stack + n; | |
7f2935c7 | 824 | } |