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str.c revision 1.96
      1 /*	$NetBSD: str.c,v 1.96 2023/06/22 16:32:09 rillig Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1989, 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Adam de Boor.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 /*
     36  * Copyright (c) 1989 by Berkeley Softworks
     37  * All rights reserved.
     38  *
     39  * This code is derived from software contributed to Berkeley by
     40  * Adam de Boor.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  */
     70 
     71 #include "make.h"
     72 
     73 /*	"@(#)str.c	5.8 (Berkeley) 6/1/90"	*/
     74 MAKE_RCSID("$NetBSD: str.c,v 1.96 2023/06/22 16:32:09 rillig Exp $");
     75 
     76 
     77 static HashTable interned_strings;
     78 
     79 
     80 /* Return the concatenation of s1 and s2, freshly allocated. */
     81 char *
     82 str_concat2(const char *s1, const char *s2)
     83 {
     84 	size_t len1 = strlen(s1);
     85 	size_t len2 = strlen(s2);
     86 	char *result = bmake_malloc(len1 + len2 + 1);
     87 	memcpy(result, s1, len1);
     88 	memcpy(result + len1, s2, len2 + 1);
     89 	return result;
     90 }
     91 
     92 /* Return the concatenation of s1, s2 and s3, freshly allocated. */
     93 char *
     94 str_concat3(const char *s1, const char *s2, const char *s3)
     95 {
     96 	size_t len1 = strlen(s1);
     97 	size_t len2 = strlen(s2);
     98 	size_t len3 = strlen(s3);
     99 	char *result = bmake_malloc(len1 + len2 + len3 + 1);
    100 	memcpy(result, s1, len1);
    101 	memcpy(result + len1, s2, len2);
    102 	memcpy(result + len1 + len2, s3, len3 + 1);
    103 	return result;
    104 }
    105 
    106 /*
    107  * Fracture a string into an array of words (as delineated by tabs or spaces)
    108  * taking quotation marks into account.
    109  *
    110  * If expand is true, quotes are removed and escape sequences such as \r, \t,
    111  * etc... are expanded. In this case, return NULL on parse errors.
    112  *
    113  * Returns the fractured words, which must be freed later using Words_Free,
    114  * unless the returned Words.words was NULL.
    115  */
    116 SubstringWords
    117 Substring_Words(const char *str, bool expand)
    118 {
    119 	size_t str_len;
    120 	char *words_buf;
    121 	size_t words_cap;
    122 	Substring *words;
    123 	size_t words_len;
    124 	char inquote;
    125 	char *word_start;
    126 	char *word_end;
    127 	const char *str_p;
    128 
    129 	/* XXX: why only hspace, not whitespace? */
    130 	cpp_skip_hspace(&str);	/* skip leading space chars. */
    131 
    132 	/* words_buf holds the words, separated by '\0'. */
    133 	str_len = strlen(str);
    134 	words_buf = bmake_malloc(str_len + 1);
    135 
    136 	words_cap = str_len / 5 > 50 ? str_len / 5 : 50;
    137 	words = bmake_malloc((words_cap + 1) * sizeof(words[0]));
    138 
    139 	/*
    140 	 * copy the string; at the same time, parse backslashes,
    141 	 * quotes and build the word list.
    142 	 */
    143 	words_len = 0;
    144 	inquote = '\0';
    145 	word_start = words_buf;
    146 	word_end = words_buf;
    147 	for (str_p = str;; str_p++) {
    148 		char ch = *str_p;
    149 		switch (ch) {
    150 		case '"':
    151 		case '\'':
    152 			if (inquote != '\0') {
    153 				if (inquote == ch)
    154 					inquote = '\0';
    155 				else
    156 					break;
    157 			} else {
    158 				inquote = ch;
    159 				/* Don't miss "" or '' */
    160 				if (word_start == NULL && str_p[1] == inquote) {
    161 					if (!expand) {
    162 						word_start = word_end;
    163 						*word_end++ = ch;
    164 					} else
    165 						word_start = word_end + 1;
    166 					str_p++;
    167 					inquote = '\0';
    168 					break;
    169 				}
    170 			}
    171 			if (!expand) {
    172 				if (word_start == NULL)
    173 					word_start = word_end;
    174 				*word_end++ = ch;
    175 			}
    176 			continue;
    177 		case ' ':
    178 		case '\t':
    179 		case '\n':
    180 			if (inquote != '\0')
    181 				break;
    182 			if (word_start == NULL)
    183 				continue;
    184 			/* FALLTHROUGH */
    185 		case '\0':
    186 			/*
    187 			 * end of a token -- make sure there's enough words
    188 			 * space and save off a pointer.
    189 			 */
    190 			if (word_start == NULL)
    191 				goto done;
    192 
    193 			*word_end++ = '\0';
    194 			if (words_len == words_cap) {
    195 				words_cap *= 2;
    196 				words = bmake_realloc(words,
    197 				    (words_cap + 1) * sizeof(words[0]));
    198 			}
    199 			words[words_len++] =
    200 			    Substring_Init(word_start, word_end - 1);
    201 			word_start = NULL;
    202 			if (ch == '\n' || ch == '\0') {
    203 				if (expand && inquote != '\0') {
    204 					SubstringWords res;
    205 
    206 					free(words);
    207 					free(words_buf);
    208 
    209 					res.words = NULL;
    210 					res.len = 0;
    211 					res.freeIt = NULL;
    212 					return res;
    213 				}
    214 				goto done;
    215 			}
    216 			continue;
    217 		case '\\':
    218 			if (!expand) {
    219 				if (word_start == NULL)
    220 					word_start = word_end;
    221 				*word_end++ = '\\';
    222 				/* catch lonely '\' at end of string */
    223 				if (str_p[1] == '\0')
    224 					continue;
    225 				ch = *++str_p;
    226 				break;
    227 			}
    228 
    229 			switch (ch = *++str_p) {
    230 			case '\0':
    231 			case '\n':
    232 				/* hmmm; fix it up as best we can */
    233 				ch = '\\';
    234 				str_p--;
    235 				break;
    236 			case 'b':
    237 				ch = '\b';
    238 				break;
    239 			case 'f':
    240 				ch = '\f';
    241 				break;
    242 			case 'n':
    243 				ch = '\n';
    244 				break;
    245 			case 'r':
    246 				ch = '\r';
    247 				break;
    248 			case 't':
    249 				ch = '\t';
    250 				break;
    251 			}
    252 			break;
    253 		}
    254 		if (word_start == NULL)
    255 			word_start = word_end;
    256 		*word_end++ = ch;
    257 	}
    258 done:
    259 	words[words_len] = Substring_Init(NULL, NULL);	/* useful for argv */
    260 
    261 	{
    262 		SubstringWords result;
    263 
    264 		result.words = words;
    265 		result.len = words_len;
    266 		result.freeIt = words_buf;
    267 		return result;
    268 	}
    269 }
    270 
    271 Words
    272 Str_Words(const char *str, bool expand)
    273 {
    274 	SubstringWords swords;
    275 	Words words;
    276 	size_t i;
    277 
    278 	swords = Substring_Words(str, expand);
    279 	if (swords.words == NULL) {
    280 		words.words = NULL;
    281 		words.len = 0;
    282 		words.freeIt = NULL;
    283 		return words;
    284 	}
    285 
    286 	words.words = bmake_malloc((swords.len + 1) * sizeof(words.words[0]));
    287 	words.len = swords.len;
    288 	words.freeIt = swords.freeIt;
    289 	for (i = 0; i < swords.len + 1; i++)
    290 		words.words[i] = UNCONST(swords.words[i].start);
    291 	free(swords.words);
    292 	return words;
    293 }
    294 
    295 /*
    296  * XXX: In the extreme edge case that one of the characters is from the basic
    297  * execution character set and the other isn't, the result of the comparison
    298  * differs depending on whether plain char is signed or unsigned.
    299  *
    300  * An example is the character range from \xE4 to 'a', where \xE4 may come
    301  * from U+00E4 'Latin small letter A with diaeresis'.
    302  *
    303  * If char is signed, \xE4 evaluates to -28, the first half of the condition
    304  * becomes -28 <= '0' && '0' <= 'a', which evaluates to true.
    305  *
    306  * If char is unsigned, \xE4 evaluates to 228, the second half of the
    307  * condition becomes 'a' <= '0' && '0' <= 228, which evaluates to false.
    308  */
    309 static bool
    310 in_range(char e1, char c, char e2)
    311 {
    312 	return (e1 <= c && c <= e2) || (e2 <= c && c <= e1);
    313 }
    314 
    315 /*
    316  * Test if a string matches a pattern like "*.[ch]". The pattern matching
    317  * characters are '*', '?' and '[]', as in fnmatch(3).
    318  *
    319  * XXX: this function does not detect or report malformed patterns.
    320  *
    321  * See varmod-match.mk for examples and edge cases.
    322  */
    323 bool
    324 Str_Match(const char *str, const char *pat)
    325 {
    326 	enum { START, SEEN_ASTERISK, END } state;
    327 	const char *fixed_str, *fixed_pat;
    328 	bool matched;
    329 
    330 	state = START;
    331 	fixed_str = str;
    332 	fixed_pat = pat;
    333 
    334 match_fixed_length:
    335 	str = fixed_str;
    336 	pat = fixed_pat;
    337 	matched = false;
    338 	for (; *pat != '\0' && *pat != '*'; str++, pat++) {
    339 		if (*str == '\0')
    340 			return false;
    341 
    342 		if (*pat == '?')	/* match any single character */
    343 			continue;
    344 
    345 		if (*pat == '[') {	/* match a character from a list */
    346 			bool neg = pat[1] == '^';
    347 			pat += neg ? 2 : 1;
    348 
    349 			for (;;) {
    350 				if (*pat == ']' || *pat == '\0') {
    351 					if (neg)
    352 						break;
    353 					goto match_done;
    354 				}
    355 				if (*pat == *str)
    356 					break;
    357 				if (pat[1] == '-') {
    358 					if (pat[2] == '\0')
    359 						return neg;
    360 					if (in_range(pat[0], *str, pat[2]))
    361 						break;
    362 					pat += 2;
    363 				}
    364 				pat++;
    365 			}
    366 			if (neg && *pat != ']' && *pat != '\0')
    367 				goto match_done;
    368 			while (*pat != ']' && *pat != '\0')
    369 				pat++;
    370 			if (*pat == '\0')
    371 				pat--;
    372 			continue;
    373 		}
    374 
    375 		if (*pat == '\\')	/* match the next character exactly */
    376 			pat++;
    377 		if (*pat != *str)
    378 			goto match_done;
    379 	}
    380 	matched = true;
    381 
    382 match_done:
    383 	switch (state) {
    384 	case START:
    385 		if (!matched)
    386 			return false;
    387 		if (*pat == '\0')
    388 			return *str == '\0';
    389 		state = SEEN_ASTERISK;
    390 		break;
    391 	default:
    392 		if (!matched) {
    393 			fixed_str++;
    394 			goto match_fixed_length;
    395 		}
    396 		if (*pat == '\0') {
    397 			size_t match_len = (size_t)(str - fixed_str);
    398 			fixed_str = str + strlen(str) - match_len;
    399 			state = END;
    400 			goto match_fixed_length;
    401 		}
    402 		break;
    403 	case END:
    404 		return matched;
    405 	}
    406 
    407 	while (*pat == '*')
    408 		pat++;
    409 	if (*pat == '\0')
    410 		return true;
    411 	fixed_str = str;
    412 	fixed_pat = pat;
    413 	goto match_fixed_length;
    414 }
    415 
    416 void
    417 Str_Intern_Init(void)
    418 {
    419 	HashTable_Init(&interned_strings);
    420 }
    421 
    422 void
    423 Str_Intern_End(void)
    424 {
    425 #ifdef CLEANUP
    426 	HashTable_Done(&interned_strings);
    427 #endif
    428 }
    429 
    430 /* Return a canonical instance of str, with unlimited lifetime. */
    431 const char *
    432 Str_Intern(const char *str)
    433 {
    434 	return HashTable_CreateEntry(&interned_strings, str, NULL)->key;
    435 }
    436