Function compile_regexp

grep.c:492–573

#endif /* !USE_LIBPCRE2 */

static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
{
	int err;
	int regflags = REG_NEWLINE;

	if (opt->pattern_type_option == GREP_PATTERN_TYPE_UNSPECIFIED)
		opt->pattern_type_option = (opt->extended_regexp_option
					    ? GREP_PATTERN_TYPE_ERE
					    : GREP_PATTERN_TYPE_BRE);

	p->word_regexp = opt->word_regexp;
	p->ignore_case = opt->ignore_case;
	p->fixed = opt->pattern_type_option == GREP_PATTERN_TYPE_FIXED;

	if (opt->pattern_type_option != GREP_PATTERN_TYPE_PCRE &&
	    memchr(p->pattern, 0, p->patternlen))
		die(_("given pattern contains NULL byte (via -f <file>). This is only supported with -P under PCRE v2"));

	p->is_fixed = is_fixed(p->pattern, p->patternlen);
#ifdef USE_LIBPCRE2
       if (!p->fixed && !p->is_fixed) {
	       const char *no_jit = "(*NO_JIT)";
	       const int no_jit_len = strlen(no_jit);
	       if (starts_with(p->pattern, no_jit) &&
		   is_fixed(p->pattern + no_jit_len,
			    p->patternlen - no_jit_len))
		       p->is_fixed = 1;
       }
#endif
	if (p->fixed || p->is_fixed) {
#ifdef USE_LIBPCRE2
		if (p->is_fixed) {
			compile_pcre2_pattern(p, opt);
		} else {
			/*
			 * E.g. t7811-grep-open.sh relies on the
			 * pattern being restored.
			 */
			char *old_pattern = p->pattern;
			size_t old_patternlen = p->patternlen;
			struct strbuf sb = STRBUF_INIT;

			/*
			 * There is the PCRE2_LITERAL flag, but it's
			 * only in PCRE v2 10.30 and later. Needing to
			 * ifdef our way around that and dealing with
			 * it + PCRE2_MULTILINE being an error is more
			 * complex than just quoting this ourselves.
			*/
			strbuf_add(&sb, "\\Q", 2);
			strbuf_add(&sb, p->pattern, p->patternlen);
			strbuf_add(&sb, "\\E", 2);

			p->pattern = sb.buf;
			p->patternlen = sb.len;
			compile_pcre2_pattern(p, opt);
			p->pattern = old_pattern;
			p->patternlen = old_patternlen;