From 9ce56b1533161b01ebb8475db61800df8fdef92c Mon Sep 17 00:00:00 2001 From: Richard Stallman Date: Wed, 16 Nov 1994 20:29:39 +0000 Subject: [PATCH] (re_opcode_t): New opcode `succeed' (re_match_2_internal): Handle `succeed'. (regex_compile): Handle RE_NO_BACKTRACKING. (re_syntax_options): Delete initializer. --- regex.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/regex.c b/regex.c index 33c7ea242c..bce02247d0 100644 --- a/regex.c +++ b/regex.c @@ -267,6 +267,9 @@ typedef enum { no_op = 0, + /* Succeed right away--no more backtracking. */ + succeed, + /* Followed by one byte giving n, then by n literal bytes. */ exactn, @@ -834,7 +837,9 @@ print_double_string (where, string1, size1, string2, size2) /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can also be assigned to arbitrarily: each pattern buffer stores its own syntax, so it can be changed between regex compilations. */ -reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS; +/* This has no initializer because initialized variables in Emacs + become read-only after dumping. */ +reg_syntax_t re_syntax_options; /* Specify the precise syntax of regexps for compilation. This provides @@ -2470,6 +2475,11 @@ regex_compile (pattern, size, syntax, bufp) if (!COMPILE_STACK_EMPTY) FREE_STACK_RETURN (REG_EPAREN); + /* If we don't want backtracking, force success + the first time we reach the end of the compiled pattern. */ + if (syntax & RE_NO_POSIX_BACKTRACKING) + BUF_PUSH (succeed); + free (compile_stack.stack); /* We have succeeded; set the length of the buffer. */ @@ -3652,6 +3662,7 @@ re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop) } } /* d != end_match_2 */ + succeed: DEBUG_PRINT1 ("Accepting match.\n"); /* If caller wants register contents data back, do it. */ @@ -3752,6 +3763,9 @@ re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop) DEBUG_PRINT1 ("EXECUTING no_op.\n"); break; + case succeed: + DEBUG_PRINT1 ("EXECUTING succeed.\n"); + goto succeed; /* Match the next n pattern characters exactly. The following byte in the pattern defines n, and the n bytes after that -- 2.30.2