[AC21.4] Minor doc and code clarity improvements in regex.c

RECOMMEND 21.4 Minor, but any clarity in the regex.c code is a worthwhile improvement IMHO. Built successfully and tested (make check passes 100% with the previous patch's new tests/automated test on Mac OS X 10.3.7). Index: src/ChangeLog =================================================================== RCS file: /Users/steve/Software/Repositories/cvs.xemacs.org/XEmacs/xemacs/src/ChangeLog,v retrieving revision 1.290.2.83 diff -u -r1.290.2.83 ChangeLog --- src/ChangeLog 2005/01/11 02:02:11 1.290.2.83 +++ src/ChangeLog 2005/01/13 12:24:53 ＠＠ -0,0 +1,19 ＠＠ +2005-01-13 Stephen J. Turnbull <stephen(a)xemacs.org&gt; + + Documentation, code clarification, and warning suppression. + + * regex.c (regex_compile): + Improve comments. + (re_match_2_internal): + Improve comments and avoid redundant braces. [Most of the big hunk + at l. 4710 is indentation; use diff -w to see the real changes.] + (alt_match_null_string_p): + (common_op_match_null_string_p): + Avoid shadowing global on Mac OS X 10.4, at least. + +2004-09-08 Stephen J. Turnbull <stephen(a)xemacs.org&gt; + + * regex.c (regcomp): Fix "unsigned comparison" warning (maybe + introduced with shy groups fix). [Already applied, probably + with the second "fix shy groups" patch of 2004-10-07.] + Index: src/regex.c =================================================================== RCS file: /Users/steve/Software/Repositories/cvs.xemacs.org/XEmacs/xemacs/src/regex.c,v retrieving revision 1.25.2.10 diff -u -r1.25.2.10 regex.c --- src/regex.c 2004/10/08 00:40:33 1.25.2.10 +++ src/regex.c 2005/01/13 12:22:03 ＠＠ -1994,6 +1994,7 ＠＠ bufp->re_nsub = 0; bufp->re_ngroups = 0; + /* Allocate index translation array if needed. */ if (bufp->external_to_internal_register == 0) { bufp->external_to_internal_register_size = INIT_REG_TRANSLATE_SIZE; ＠＠ -2002,6 +2003,7 ＠＠ int); } + /* Initialize translations to impossible value to aid debugging. */ { int i; ＠＠ -2614,6 +2616,8 ＠＠ r = ++regnum; bufp->re_ngroups++; if (!shy) + /* Record the translation from capturing group index to + register number, reallocating table as needed. */ { bufp->re_nsub++; while (bufp->external_to_internal_register_size <= ＠＠ -4710,62 +4714,62 ＠＠ succeed_label: DEBUG_PRINT1 ("Accepting match.\n"); - /* If caller wants register contents data back, do it. */ - { - int num_nonshy_regs = bufp->re_nsub + 1; - if (regs && !bufp->no_sub) - { - /* Have the register data arrays been allocated? */ - if (bufp->regs_allocated == REGS_UNALLOCATED) - { /* No. So allocate them with malloc. We need one - extra element beyond `num_regs' for the `-1' marker - GNU code uses. */ - regs->num_regs = MAX (RE_NREGS, num_nonshy_regs + 1); - regs->start = TALLOC (regs->num_regs, regoff_t); - regs->end = TALLOC (regs->num_regs, regoff_t); - if (regs->start == NULL || regs->end == NULL) - { - FREE_VARIABLES (); - return -2; - } - bufp->regs_allocated = REGS_REALLOCATE; - } - else if (bufp->regs_allocated == REGS_REALLOCATE) - { /* Yes. If we need more elements than were already - allocated, reallocate them. If we need fewer, just - leave it alone. */ - if (regs->num_regs < num_nonshy_regs + 1) - { - regs->num_regs = num_nonshy_regs + 1; - RETALLOC (regs->start, regs->num_regs, regoff_t); - RETALLOC (regs->end, regs->num_regs, regoff_t); - if (regs->start == NULL || regs->end == NULL) - { - FREE_VARIABLES (); - return -2; - } - } - } - else - { - /* The braces fend off a "empty body in an else-statement" - warning under GCC when assert expands to nothing. */ - assert (bufp->regs_allocated == REGS_FIXED); - } + /* If caller wants register contents data back, fill REGS. */ + if (regs && !bufp->no_sub) + { + int num_nonshy_regs = bufp->re_nsub + 1; + /* Have the register data arrays been allocated? */ + if (bufp->regs_allocated == REGS_UNALLOCATED) + { /* No. So allocate them with malloc. We need one + extra element beyond `num_regs' for the `-1' marker + GNU code uses. */ + regs->num_regs = MAX (RE_NREGS, num_nonshy_regs + 1); + regs->start = TALLOC (regs->num_regs, regoff_t); + regs->end = TALLOC (regs->num_regs, regoff_t); + if (regs->start == NULL || regs->end == NULL) + { + FREE_VARIABLES (); + return -2; + } + bufp->regs_allocated = REGS_REALLOCATE; + } + else if (bufp->regs_allocated == REGS_REALLOCATE) + { /* Yes. If we need more elements than were already + allocated, reallocate them. If we need fewer, just + leave it alone. */ + if (regs->num_regs < num_nonshy_regs + 1) + { + regs->num_regs = num_nonshy_regs + 1; + RETALLOC (regs->start, regs->num_regs, regoff_t); + RETALLOC (regs->end, regs->num_regs, regoff_t); + if (regs->start == NULL || regs->end == NULL) + { + FREE_VARIABLES (); + return -2; + } + } + } + else + { + /* The braces fend off a "empty body in an else-statement" + warning under GCC when assert expands to nothing. */ + assert (bufp->regs_allocated == REGS_FIXED); + } - /* Convert the pointer data in `regstart' and `regend' to - indices. Register zero has to be set differently, - since we haven't kept track of any info for it. */ - if (regs->num_regs > 0) - { - regs->start[0] = pos; - regs->end[0] = (MATCHING_IN_FIRST_STRING - ? ((regoff_t) (d - string1)) - : ((regoff_t) (d - string2 + size1))); - } + /* Convert the pointer data in `regstart' and `regend' to + indices. Register zero has to be set differently, + since we haven't kept track of any info for it. */ + if (regs->num_regs > 0) + { + regs->start[0] = pos; + regs->end[0] = (MATCHING_IN_FIRST_STRING + ? ((regoff_t) (d - string1)) + : ((regoff_t) (d - string2 + size1))); + } - /* Go through the first `min (num_regs, regs->num_regs)' - registers, since that is all we initialized. */ + /* Map over the NUM_NONSHY_REGS non-shy internal registers. + Copy each into the corresponding external register. + N.B. MCNT indexes external registers. */ for (mcnt = 1; mcnt < MIN (num_nonshy_regs, regs->num_regs); mcnt++) ＠＠ -4783,7 +4787,6 ＠＠ } } } /* regs && !bufp->no_sub */ - } /* If we have regs and the regs structure has more elements than were in the pattern, set the extra elements to -1. If we ＠＠ -5958,7 +5961,7 ＠＠ static re_bool group_match_null_string_p (unsigned char **p, unsigned char *end, - register_info_type *reg_info) + register_info_type *register_info) { int mcnt; /* Point to after the args to the start_memory. */ ＠＠ -6007,7 +6010,7 ＠＠ its number. */ if (!alt_match_null_string_p (p1, p1 + mcnt - 3, - reg_info)) + register_info)) return false; /* Move to right after this alternative, including the ＠＠ -6036,7 +6039,7 ＠＠ the length of the alternative. */ EXTRACT_NUMBER (mcnt, p1 - 2); - if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info)) + if (!alt_match_null_string_p (p1, p1 + mcnt, register_info)) return false; p1 += mcnt; /* Get past the n-th alternative. */ ＠＠ -6051,7 +6054,7 ＠＠ default: - if (!common_op_match_null_string_p (&p1, end, reg_info)) + if (!common_op_match_null_string_p (&p1, end, register_info)) return false; } } /* while p1 < end */ ＠＠ -6066,7 +6069,7 ＠＠ static re_bool alt_match_null_string_p (unsigned char *p, unsigned char *end, - register_info_type *reg_info) + register_info_type *register_info) { int mcnt; unsigned char *p1 = p; ＠＠ -6086,7 +6089,7 ＠＠ break; default: - if (!common_op_match_null_string_p (&p1, end, reg_info)) + if (!common_op_match_null_string_p (&p1, end, register_info)) return false; } } /* while p1 < end */ ＠＠ -6102,7 +6105,7 ＠＠ static re_bool common_op_match_null_string_p (unsigned char **p, unsigned char *end, - register_info_type *reg_info) + register_info_type *register_info) { int mcnt; re_bool ret; ＠＠ -6130,13 +6133,14 ＠＠ case start_memory: reg_no = *p1; assert (reg_no > 0 && reg_no <= MAX_REGNUM); - ret = group_match_null_string_p (&p1, end, reg_info); + ret = group_match_null_string_p (&p1, end, register_info); /* Have to set this here in case we're checking a group which contains a group and a back reference to it. */ - if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE) - REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret; + if (REG_MATCH_NULL_STRING_P (register_info[reg_no]) == + MATCH_NULL_UNSET_VALUE) + REG_MATCH_NULL_STRING_P (register_info[reg_no]) = ret; if (!ret) return false; ＠＠ -6167,7 +6171,7 ＠＠ break; case duplicate: - if (!REG_MATCH_NULL_STRING_P (reg_info[*p1])) + if (!REG_MATCH_NULL_STRING_P (register_info[*p1])) return false; break; -- Institute of Policy and Planning Sciences http://turnbull.sk.tsukuba.ac.jp University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Ask not how you can "do" free software business; ask what your business can "do for" free software.