/*      $NetBSD: str.c,v 1.106 2025/06/28 21:09:43 rillig Exp $ */

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "make.h"

/*      "@(#)str.c      5.8 (Berkeley) 6/1/90"  */
MAKE_RCSID("$NetBSD: str.c,v 1.106 2025/06/28 21:09:43 rillig Exp $");


static HashTable interned_strings;


/* Return the concatenation of s1 and s2, freshly allocated. */
char *
str_concat2(const char *s1, const char *s2)
{
        size_t len1 = strlen(s1);
        size_t len2 = strlen(s2);
        char *result = bmake_malloc(len1 + len2 + 1);
        memcpy(result, s1, len1);
        memcpy(result + len1, s2, len2 + 1);
        return result;
}

/* Return the concatenation of s1, s2 and s3, freshly allocated. */
char *
str_concat3(const char *s1, const char *s2, const char *s3)
{
        size_t len1 = strlen(s1);
        size_t len2 = strlen(s2);
        size_t len3 = strlen(s3);
        char *result = bmake_malloc(len1 + len2 + len3 + 1);
        memcpy(result, s1, len1);
        memcpy(result + len1, s2, len2);
        memcpy(result + len1 + len2, s3, len3 + 1);
        return result;
}

/*
 * Fracture a string into an array of words (as delineated by tabs or spaces)
 * taking quotation marks into account.
 *
 * A string that is empty or only contains whitespace nevertheless results in
 * a single word.  This is unexpected in many places, and the caller needs to
 * correct for this edge case.
 *
 * If expand is true, quotes are removed and escape sequences such as \r, \t,
 * etc... are expanded. In this case, return NULL on parse errors.
 *
 * Returns the fractured words, which must be freed later using Words_Free,
 * unless the returned Words.words was NULL.
 */
SubstringWords
Substring_Words(const char *str, bool expand)
{
        size_t str_len;
        char *words_buf;
        size_t words_cap;
        Substring *words;
        size_t words_len;
        char inquote;
        char *word_start;
        char *word_end;
        const char *str_p;

        /* XXX: why only hspace, not whitespace? */
        cpp_skip_hspace(&str);  /* skip leading space chars. */

        /* words_buf holds the words, separated by '\0'. */
        str_len = strlen(str);
        words_buf = bmake_malloc(str_len + 1);

        words_cap = str_len / 5 > 50 ? str_len / 5 : 50;
        words = bmake_malloc((words_cap + 1) * sizeof(words[0]));

        /*
         * copy the string; at the same time, parse backslashes,
         * quotes and build the word list.
         */
        words_len = 0;
        inquote = '\0';
        word_start = words_buf;
        word_end = words_buf;
        for (str_p = str;; str_p++) {
                char ch = *str_p;
                switch (ch) {
                case '"':
                case '\'':
                        if (inquote != '\0') {
                                if (inquote == ch)
                                        inquote = '\0';
                                else
                                        break;
                        } else {
                                inquote = ch;
                                /* Don't miss "" or '' */
                                if (word_start == NULL && str_p[1] == inquote) {
                                        if (!expand) {
                                                word_start = word_end;
                                                *word_end++ = ch;
                                        } else
                                                word_start = word_end + 1;
                                        str_p++;
                                        inquote = '\0';
                                        break;
                                }
                        }
                        if (!expand) {
                                if (word_start == NULL)
                                        word_start = word_end;
                                *word_end++ = ch;
                        }
                        continue;
                case ' ':
                case '\t':
                case '\n':
                        if (inquote != '\0')
                                break;
                        if (word_start == NULL)
                                continue;
                        /* FALLTHROUGH */
                case '\0':
                        /*
                         * end of a token -- make sure there's enough words
                         * space and save off a pointer.
                         */
                        if (word_start == NULL)
                                goto done;

                        *word_end++ = '\0';
                        if (words_len == words_cap) {
                                words_cap *= 2;
                                words = bmake_realloc(words,
                                    (words_cap + 1) * sizeof(words[0]));
                        }
                        words[words_len++] =
                            Substring_Init(word_start, word_end - 1);
                        word_start = NULL;
                        if (ch == '\n' || ch == '\0') {
                                if (expand && inquote != '\0') {
                                        SubstringWords res;

                                        free(words);
                                        free(words_buf);

                                        res.words = NULL;
                                        res.len = 0;
                                        res.freeIt = NULL;
                                        return res;
                                }
                                goto done;
                        }
                        continue;
                case '\\':
                        if (!expand) {
                                if (word_start == NULL)
                                        word_start = word_end;
                                *word_end++ = '\\';
                                /* catch lonely '\' at end of string */
                                if (str_p[1] == '\0')
                                        continue;
                                ch = *++str_p;
                                break;
                        }

                        switch (ch = *++str_p) {
                        case '\0':
                        case '\n':
                                /* hmmm; fix it up as best we can */
                                ch = '\\';
                                str_p--;
                                break;
                        case 'b':
                                ch = '\b';
                                break;
                        case 'f':
                                ch = '\f';
                                break;
                        case 'n':
                                ch = '\n';
                                break;
                        case 'r':
                                ch = '\r';
                                break;
                        case 't':
                                ch = '\t';
                                break;
                        }
                        break;
                }
                if (word_start == NULL)
                        word_start = word_end;
                *word_end++ = ch;
        }
done:
        words[words_len] = Substring_Init(NULL, NULL);  /* useful for argv */

        {
                SubstringWords result;

                result.words = words;
                result.len = words_len;
                result.freeIt = words_buf;
                return result;
        }
}

Words
Str_Words(const char *str, bool expand)
{
        SubstringWords swords;
        Words words;
        size_t i;

        swords = Substring_Words(str, expand);
        if (swords.words == NULL) {
                words.words = NULL;
                words.len = 0;
                words.freeIt = NULL;
                return words;
        }

        words.words = bmake_malloc((swords.len + 1) * sizeof(words.words[0]));
        words.len = swords.len;
        words.freeIt = swords.freeIt;
        for (i = 0; i < swords.len + 1; i++)
                words.words[i] = UNCONST(swords.words[i].start);
        free(swords.words);
        return words;
}

/*
 * Test if a string matches a pattern like "*.[ch]". The pattern matching
 * characters are '*', '?' and '[]', as in fnmatch(3).
 *
 * See varmod-match.mk for examples and edge cases.
 */
StrMatchResult
Str_Match(const char *str, const char *pat)
{
        StrMatchResult res = { NULL, false };
        bool asterisk = false;
        const char *fixed_str = str;
        const char *fixed_pat = pat;

match_fixed_length:
        str = fixed_str;
        pat = fixed_pat;
        for (; *pat != '\0' && *pat != '*'; str++, pat++) {
                if (*str == '\0')
                        return res;

                if (*pat == '?')        /* match any single character */
                        continue;

                if (*pat == '[') {      /* match a character from a list */
                        bool neg = pat[1] == '^';
                        pat += neg ? 2 : 1;

                next_char_in_list:
                        if (*pat == '\0')
                                res.error = "Unfinished character list";
                        if (*pat == ']' || *pat == '\0') {
                                if (neg)
                                        goto end_of_char_list;
                                goto no_match;
                        }
                        if (*pat == *str)
                                goto end_of_char_list;
                        if (pat[1] == '-' && pat[2] == '\0') {
                                res.error = "Unfinished character range";
                                res.matched = neg;
                                return res;
                        }
                        if (pat[1] == '-') {
                                unsigned char e1 = (unsigned char)pat[0];
                                unsigned char c = (unsigned char)*str;
                                unsigned char e2 = (unsigned char)pat[2];
                                if ((e1 <= c && c <= e2)
                                    || (e2 <= c && c <= e1))
                                        goto end_of_char_list;
                                pat += 2;
                        }
                        pat++;
                        goto next_char_in_list;

                end_of_char_list:
                        if (neg && *pat != ']' && *pat != '\0')
                                goto no_match;
                        while (*pat != ']' && *pat != '\0')
                                pat++;
                        if (*pat == '\0') {
                                res.error = "Unfinished character list";
                                pat--;
                        }
                        continue;
                }

                if (*pat == '\\') {     /* match the next character exactly */
                        pat++;
                        if (*pat == '\0')
                                res.error = "Unfinished backslash at the end";
                }
                if (*pat != *str) {
                        if (asterisk && str == fixed_str) {
                                while (*str != '\0' && *str != *pat)
                                        str++;
                                fixed_str = str;
                                goto match_fixed_length;
                        }
                        goto no_match;
                }
        }

        if (*pat == '*') {
                asterisk = true;
                while (*pat == '*')
                        pat++;
                if (*pat == '\0') {
                        res.matched = true;
                        return res;
                }
                fixed_str = str;
                fixed_pat = pat;
                goto match_fixed_length;
        }
        if (asterisk && *str != '\0') {
                fixed_str += strlen(str);
                goto match_fixed_length;
        }
        res.matched = *str == '\0';
        return res;

no_match:
        if (!asterisk)
                return res;
        fixed_str++;
        goto match_fixed_length;
}

void
Str_Intern_Init(void)
{
        HashTable_Init(&interned_strings);
}

#ifdef CLEANUP
void
Str_Intern_End(void)
{
        HashTable_Done(&interned_strings);
}
#endif

/* Return a canonical instance of str, with unlimited lifetime. */
const char *
Str_Intern(const char *str)
{
        return HashTable_CreateEntry(&interned_strings, str, NULL)->key;
}