diff options
| -rw-r--r-- | include/intprops.h | 18 | ||||
| -rw-r--r-- | include/regex.h | 3 | ||||
| -rw-r--r-- | misc/sys/cdefs.h | 22 | ||||
| -rw-r--r-- | posix/regcomp.c | 8 | ||||
| -rw-r--r-- | posix/regex.c | 1 | ||||
| -rw-r--r-- | posix/regex.h | 49 | ||||
| -rw-r--r-- | posix/regex_internal.c | 10 | ||||
| -rw-r--r-- | posix/regex_internal.h | 8 | ||||
| -rw-r--r-- | posix/regexec.c | 101 |
9 files changed, 142 insertions, 78 deletions
diff --git a/include/intprops.h b/include/intprops.h index 2b6e5e93ed..3fe64e82e9 100644 --- a/include/intprops.h +++ b/include/intprops.h @@ -132,7 +132,8 @@ operators might not yield numerically correct answers due to arithmetic overflow. They do not rely on undefined or implementation-defined behavior. Their implementations are simple - and straightforward, but they are a bit harder to use than the + and straightforward, but they are harder to use and may be less + efficient than the INT_<op>_WRAPV, INT_<op>_OK, and INT_<op>_OVERFLOW macros described below. Example usage: @@ -157,6 +158,9 @@ must have minimum value MIN and maximum MAX. Unsigned types should use a zero MIN of the proper type. + Because all arguments are subject to integer promotions, these + macros typically do not work on types narrower than 'int'. + These macros are tuned for constant MIN and MAX. For commutative operations such as A + B, they are also tuned for constant B. */ @@ -338,9 +342,15 @@ arguments should not have side effects. The WRAPV macros are not constant expressions. They support only - +, binary -, and *. Because the WRAPV macros convert the result, - they report overflow in different circumstances than the OVERFLOW - macros do. + +, binary -, and *. + + Because the WRAPV macros convert the result, they report overflow + in different circumstances than the OVERFLOW macros do. For + example, in the typical case with 16-bit 'short' and 32-bit 'int', + if A, B and R are all of type 'short' then INT_ADD_OVERFLOW (A, B) + returns false because the addition cannot overflow after A and B + are converted to 'int', whereas INT_ADD_WRAPV (A, B, &R) returns + true or false depending on whether the sum fits into 'short'. These macros are tuned for their last input argument being a constant. diff --git a/include/regex.h b/include/regex.h index 24eca2c297..34fb67d855 100644 --- a/include/regex.h +++ b/include/regex.h @@ -37,7 +37,8 @@ extern int __regcomp (regex_t *__preg, const char *__pattern, int __cflags); libc_hidden_proto (__regcomp) extern int __regexec (const regex_t *__preg, const char *__string, - size_t __nmatch, regmatch_t __pmatch[], int __eflags); + size_t __nmatch, regmatch_t __pmatch[__nmatch], + int __eflags); libc_hidden_proto (__regexec) extern size_t __regerror (int __errcode, const regex_t *__preg, diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h index e490fc1aeb..4dac9d264d 100644 --- a/misc/sys/cdefs.h +++ b/misc/sys/cdefs.h @@ -318,16 +318,18 @@ #endif /* The nonnull function attribute marks pointer parameters that - must not be NULL. */ -#ifndef __nonnull + must not be NULL. This has the name __nonnull in glibc, + and __attribute_nonnull__ in files shared with Gnulib to avoid + collision with a different __nonnull in DragonFlyBSD 5.9. */ +#ifndef __attribute_nonnull__ # if __GNUC_PREREQ (3,3) || __glibc_has_attribute (__nonnull__) -# define __nonnull(params) __attribute__ ((__nonnull__ params)) +# define __attribute_nonnull__(params) __attribute__ ((__nonnull__ params)) # else -# define __nonnull(params) +# define __attribute_nonnull__(params) # endif -#elif !defined __GLIBC__ -# undef __nonnull -# define __nonnull(params) _GL_ATTRIBUTE_NONNULL (params) +#endif +#ifndef __nonnull +# define __nonnull(params) __attribute_nonnull__ (params) #endif /* The returns_nonnull function attribute marks the return type of the function @@ -493,9 +495,9 @@ [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })] #endif -/* The #ifndef lets Gnulib avoid including these on non-glibc - platforms, where the includes typically do not exist. */ -#ifdef __GLIBC__ +/* Gnulib avoids including these, as they don't work on non-glibc or + older glibc platforms. */ +#ifndef __GNULIB_CDEFS # include <bits/wordsize.h> # include <bits/long-double.h> #endif diff --git a/posix/regcomp.c b/posix/regcomp.c index d93698ae78..887e5b5068 100644 --- a/posix/regcomp.c +++ b/posix/regcomp.c @@ -1695,12 +1695,14 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root) reg_errcode_t err; Idx i; re_node_set eclosure; - bool ok; bool incomplete = false; err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1); if (__glibc_unlikely (err != REG_NOERROR)) return err; + /* An epsilon closure includes itself. */ + eclosure.elems[eclosure.nelem++] = node; + /* This indicates that we are calculating this node now. We reference this value to avoid infinite loop. */ dfa->eclosures[node].nelem = -1; @@ -1753,10 +1755,6 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root) } } - /* An epsilon closure includes itself. */ - ok = re_node_set_insert (&eclosure, node); - if (__glibc_unlikely (! ok)) - return REG_ESPACE; if (incomplete && !root) dfa->eclosures[node].nelem = 0; else diff --git a/posix/regex.c b/posix/regex.c index 7296be0f08..d32863972c 100644 --- a/posix/regex.c +++ b/posix/regex.c @@ -24,6 +24,7 @@ # if __GNUC_PREREQ (4, 6) # pragma GCC diagnostic ignored "-Wsuggest-attribute=pure" +# pragma GCC diagnostic ignored "-Wvla" # endif # if __GNUC_PREREQ (4, 3) # pragma GCC diagnostic ignored "-Wold-style-definition" diff --git a/posix/regex.h b/posix/regex.h index 14fb1d8364..adb69768ee 100644 --- a/posix/regex.h +++ b/posix/regex.h @@ -522,6 +522,30 @@ typedef struct /* Declarations for routines. */ +#ifndef _REGEX_NELTS +# if (defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__ \ + && !defined __STDC_NO_VLA__) +# define _REGEX_NELTS(n) n +# else +# define _REGEX_NELTS(n) +# endif +#endif + +#if defined __GNUC__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__) +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wvla" +#endif + +#ifndef _Attr_access_ +# ifdef __attr_access +# define _Attr_access_(arg) __attr_access (arg) +# elif defined __GNUC__ && 10 <= __GNUC__ +# define _Attr_access_(x) __attribute__ ((__access__ x)) +# else +# define _Attr_access_(x) +# endif +#endif + #ifdef __USE_GNU /* Sets the current default syntax to SYNTAX, and return the old syntax. You can also simply assign to the 're_syntax_options' variable. */ @@ -537,7 +561,7 @@ extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax); 'regfree'. */ extern const char *re_compile_pattern (const char *__pattern, size_t __length, struct re_pattern_buffer *__buffer) - __attr_access ((__read_only__, 1, 2)); + _Attr_access_ ((__read_only__, 1, 2)); /* Compile a fastmap for the compiled pattern in BUFFER; used to @@ -555,7 +579,7 @@ extern regoff_t re_search (struct re_pattern_buffer *__buffer, const char *__String, regoff_t __length, regoff_t __start, regoff_t __range, struct re_registers *__regs) - __attr_access ((__read_only__, 2, 3)); + _Attr_access_ ((__read_only__, 2, 3)); /* Like 're_search', but search in the concatenation of STRING1 and @@ -566,8 +590,8 @@ extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer, regoff_t __start, regoff_t __range, struct re_registers *__regs, regoff_t __stop) - __attr_access ((__read_only__, 2, 3)) - __attr_access ((__read_only__, 4, 5)); + _Attr_access_ ((__read_only__, 2, 3)) + _Attr_access_ ((__read_only__, 4, 5)); /* Like 're_search', but return how many characters in STRING the regexp @@ -575,7 +599,7 @@ extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer, extern regoff_t re_match (struct re_pattern_buffer *__buffer, const char *__String, regoff_t __length, regoff_t __start, struct re_registers *__regs) - __attr_access ((__read_only__, 2, 3)); + _Attr_access_ ((__read_only__, 2, 3)); /* Relates to 're_match' as 're_search_2' relates to 're_search'. */ @@ -584,8 +608,8 @@ extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer, const char *__string2, regoff_t __length2, regoff_t __start, struct re_registers *__regs, regoff_t __stop) - __attr_access ((__read_only__, 2, 3)) - __attr_access ((__read_only__, 4, 5)); + _Attr_access_ ((__read_only__, 2, 3)) + _Attr_access_ ((__read_only__, 4, 5)); /* Set REGS to hold NUM_REGS registers, storing them in STARTS and @@ -654,16 +678,19 @@ extern int regcomp (regex_t *_Restrict_ __preg, extern int regexec (const regex_t *_Restrict_ __preg, const char *_Restrict_ __String, size_t __nmatch, - regmatch_t __pmatch[_Restrict_arr_], - int __eflags) - __attr_access ((__write_only__, 4, 3)); + regmatch_t __pmatch[_Restrict_arr_ + _REGEX_NELTS (__nmatch)], + int __eflags); extern size_t regerror (int __errcode, const regex_t *_Restrict_ __preg, char *_Restrict_ __errbuf, size_t __errbuf_size) - __attr_access ((__write_only__, 3, 4)); + _Attr_access_ ((__write_only__, 3, 4)); extern void regfree (regex_t *__preg); +#if defined __GNUC__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__) +# pragma GCC diagnostic pop +#endif #ifdef __cplusplus } diff --git a/posix/regex_internal.c b/posix/regex_internal.c index 9dd387ef85..aefcfa2f52 100644 --- a/posix/regex_internal.c +++ b/posix/regex_internal.c @@ -1211,6 +1211,10 @@ re_node_set_merge (re_node_set *dest, const re_node_set *src) if (__glibc_unlikely (dest->nelem == 0)) { + /* Although we already guaranteed above that dest->alloc != 0 and + therefore dest->elems != NULL, add a debug assertion to pacify + GCC 11.2.1's -fanalyzer. */ + DEBUG_ASSERT (dest->elems); dest->nelem = src->nelem; memcpy (dest->elems, src->elems, src->nelem * sizeof (Idx)); return REG_NOERROR; @@ -1286,7 +1290,10 @@ re_node_set_insert (re_node_set *set, Idx elem) if (__glibc_unlikely (set->nelem) == 0) { - /* We already guaranteed above that set->alloc != 0. */ + /* Although we already guaranteed above that set->alloc != 0 and + therefore set->elems != NULL, add a debug assertion to pacify + GCC 11.2 -fanalyzer. */ + DEBUG_ASSERT (set->elems); set->elems[0] = elem; ++set->nelem; return true; @@ -1314,6 +1321,7 @@ re_node_set_insert (re_node_set *set, Idx elem) { for (idx = set->nelem; set->elems[idx - 1] > elem; idx--) set->elems[idx] = set->elems[idx - 1]; + DEBUG_ASSERT (set->elems[idx - 1] < elem); } /* Insert the new element. */ diff --git a/posix/regex_internal.h b/posix/regex_internal.h index edcdc07e99..1245e782ff 100644 --- a/posix/regex_internal.h +++ b/posix/regex_internal.h @@ -32,6 +32,10 @@ #include <stdbool.h> #include <stdint.h> +#ifndef _LIBC +# include <dynarray.h> +#endif + #include <intprops.h> #include <verify.h> @@ -49,14 +53,14 @@ # define lock_fini(lock) ((void) 0) # define lock_lock(lock) __libc_lock_lock (lock) # define lock_unlock(lock) __libc_lock_unlock (lock) -#elif defined GNULIB_LOCK && !defined USE_UNLOCKED_IO +#elif defined GNULIB_LOCK && !defined GNULIB_REGEX_SINGLE_THREAD # include "glthread/lock.h" # define lock_define(name) gl_lock_define (, name) # define lock_init(lock) glthread_lock_init (&(lock)) # define lock_fini(lock) glthread_lock_destroy (&(lock)) # define lock_lock(lock) glthread_lock_lock (&(lock)) # define lock_unlock(lock) glthread_lock_unlock (&(lock)) -#elif defined GNULIB_PTHREAD && !defined USE_UNLOCKED_IO +#elif defined GNULIB_PTHREAD && !defined GNULIB_REGEX_SINGLE_THREAD # include <pthread.h> # define lock_define(name) pthread_mutex_t name; # define lock_init(lock) pthread_mutex_init (&(lock), 0) diff --git a/posix/regexec.c b/posix/regexec.c index f7b4f9cfc3..83e9aaf8ca 100644 --- a/posix/regexec.c +++ b/posix/regexec.c @@ -59,7 +59,7 @@ static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch, Idx cur_idx, Idx nmatch); static reg_errcode_t push_fail_stack (struct re_fail_stack_t *fs, Idx str_idx, Idx dest_node, Idx nregs, - regmatch_t *regs, + regmatch_t *regs, regmatch_t *prevregs, re_node_set *eps_via_nodes); static reg_errcode_t set_regs (const regex_t *preg, const re_match_context_t *mctx, @@ -186,11 +186,12 @@ static reg_errcode_t extend_buffers (re_match_context_t *mctx, int min_len); REG_NOTBOL is set, then ^ does not match at the beginning of the string; if REG_NOTEOL is set, then $ does not match at the end. - We return 0 if we find a match and REG_NOMATCH if not. */ + Return 0 if a match is found, REG_NOMATCH if not, REG_BADPAT if + EFLAGS is invalid. */ int regexec (const regex_t *__restrict preg, const char *__restrict string, - size_t nmatch, regmatch_t pmatch[], int eflags) + size_t nmatch, regmatch_t pmatch[_REGEX_NELTS (nmatch)], int eflags) { reg_errcode_t err; Idx start, length; @@ -234,7 +235,7 @@ int attribute_compat_text_section __compat_regexec (const regex_t *__restrict preg, const char *__restrict string, size_t nmatch, - regmatch_t pmatch[], int eflags) + regmatch_t pmatch[_REGEX_NELTS (nmatch)], int eflags) { return regexec (preg, string, nmatch, pmatch, eflags & (REG_NOTBOL | REG_NOTEOL)); @@ -269,8 +270,8 @@ compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0); strings.) On success, re_match* functions return the length of the match, re_search* - return the position of the start of the match. Return value -1 means no - match was found and -2 indicates an internal error. */ + return the position of the start of the match. They return -1 on + match failure, -2 on error. */ regoff_t re_match (struct re_pattern_buffer *bufp, const char *string, Idx length, @@ -1206,27 +1207,30 @@ check_halt_state_context (const re_match_context_t *mctx, /* Compute the next node to which "NFA" transit from NODE("NFA" is a NFA corresponding to the DFA). Return the destination node, and update EPS_VIA_NODES; - return -1 in case of errors. */ + return -1 on match failure, -2 on error. */ static Idx proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs, + regmatch_t *prevregs, Idx *pidx, Idx node, re_node_set *eps_via_nodes, struct re_fail_stack_t *fs) { const re_dfa_t *const dfa = mctx->dfa; - Idx i; - bool ok; if (IS_EPSILON_NODE (dfa->nodes[node].type)) { re_node_set *cur_nodes = &mctx->state_log[*pidx]->nodes; re_node_set *edests = &dfa->edests[node]; - Idx dest_node; - ok = re_node_set_insert (eps_via_nodes, node); - if (__glibc_unlikely (! ok)) - return -2; - /* Pick up a valid destination, or return -1 if none - is found. */ - for (dest_node = -1, i = 0; i < edests->nelem; ++i) + + if (! re_node_set_contains (eps_via_nodes, node)) + { + bool ok = re_node_set_insert (eps_via_nodes, node); + if (__glibc_unlikely (! ok)) + return -2; + } + + /* Pick a valid destination, or return -1 if none is found. */ + Idx dest_node = -1; + for (Idx i = 0; i < edests->nelem; i++) { Idx candidate = edests->elems[i]; if (!re_node_set_contains (cur_nodes, candidate)) @@ -1244,7 +1248,7 @@ proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs, /* Otherwise, push the second epsilon-transition on the fail stack. */ else if (fs != NULL && push_fail_stack (fs, *pidx, candidate, nregs, regs, - eps_via_nodes)) + prevregs, eps_via_nodes)) return -2; /* We know we are going to exit. */ @@ -1288,7 +1292,7 @@ proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs, if (naccepted == 0) { Idx dest_node; - ok = re_node_set_insert (eps_via_nodes, node); + bool ok = re_node_set_insert (eps_via_nodes, node); if (__glibc_unlikely (! ok)) return -2; dest_node = dfa->edests[node].elems[0]; @@ -1317,7 +1321,8 @@ proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs, static reg_errcode_t __attribute_warn_unused_result__ push_fail_stack (struct re_fail_stack_t *fs, Idx str_idx, Idx dest_node, - Idx nregs, regmatch_t *regs, re_node_set *eps_via_nodes) + Idx nregs, regmatch_t *regs, regmatch_t *prevregs, + re_node_set *eps_via_nodes) { reg_errcode_t err; Idx num = fs->num++; @@ -1333,25 +1338,30 @@ push_fail_stack (struct re_fail_stack_t *fs, Idx str_idx, Idx dest_node, } fs->stack[num].idx = str_idx; fs->stack[num].node = dest_node; - fs->stack[num].regs = re_malloc (regmatch_t, nregs); + fs->stack[num].regs = re_malloc (regmatch_t, 2 * nregs); if (fs->stack[num].regs == NULL) return REG_ESPACE; memcpy (fs->stack[num].regs, regs, sizeof (regmatch_t) * nregs); + memcpy (fs->stack[num].regs + nregs, prevregs, sizeof (regmatch_t) * nregs); err = re_node_set_init_copy (&fs->stack[num].eps_via_nodes, eps_via_nodes); return err; } static Idx pop_fail_stack (struct re_fail_stack_t *fs, Idx *pidx, Idx nregs, - regmatch_t *regs, re_node_set *eps_via_nodes) + regmatch_t *regs, regmatch_t *prevregs, + re_node_set *eps_via_nodes) { + if (fs == NULL || fs->num == 0) + return -1; Idx num = --fs->num; - DEBUG_ASSERT (num >= 0); *pidx = fs->stack[num].idx; memcpy (regs, fs->stack[num].regs, sizeof (regmatch_t) * nregs); + memcpy (prevregs, fs->stack[num].regs + nregs, sizeof (regmatch_t) * nregs); re_node_set_free (eps_via_nodes); re_free (fs->stack[num].regs); *eps_via_nodes = fs->stack[num].eps_via_nodes; + DEBUG_ASSERT (0 <= fs->stack[num].node); return fs->stack[num].node; } @@ -1407,33 +1417,32 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch, { update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch); - if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node) + if ((idx == pmatch[0].rm_eo && cur_node == mctx->last_node) + || (fs && re_node_set_contains (&eps_via_nodes, cur_node))) { Idx reg_idx; + cur_node = -1; if (fs) { for (reg_idx = 0; reg_idx < nmatch; ++reg_idx) if (pmatch[reg_idx].rm_so > -1 && pmatch[reg_idx].rm_eo == -1) - break; - if (reg_idx == nmatch) - { - re_node_set_free (&eps_via_nodes); - regmatch_list_free (&prev_match); - return free_fail_stack_return (fs); - } - cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, - &eps_via_nodes); + { + cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, + prev_idx_match, &eps_via_nodes); + break; + } } - else + if (cur_node < 0) { re_node_set_free (&eps_via_nodes); regmatch_list_free (&prev_match); - return REG_NOERROR; + return free_fail_stack_return (fs); } } /* Proceed to next node. */ - cur_node = proceed_next_node (mctx, nmatch, pmatch, &idx, cur_node, + cur_node = proceed_next_node (mctx, nmatch, pmatch, prev_idx_match, + &idx, cur_node, &eps_via_nodes, fs); if (__glibc_unlikely (cur_node < 0)) @@ -1445,13 +1454,13 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch, free_fail_stack_return (fs); return REG_ESPACE; } - if (fs) - cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, - &eps_via_nodes); - else + cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, + prev_idx_match, &eps_via_nodes); + if (cur_node < 0) { re_node_set_free (&eps_via_nodes); regmatch_list_free (&prev_match); + free_fail_stack_return (fs); return REG_NOMATCH; } } @@ -1495,10 +1504,10 @@ update_regs (const re_dfa_t *dfa, regmatch_t *pmatch, } else if (type == OP_CLOSE_SUBEXP) { + /* We are at the last node of this sub expression. */ Idx reg_num = dfa->nodes[cur_node].opr.idx + 1; if (reg_num < nmatch) { - /* We are at the last node of this sub expression. */ if (pmatch[reg_num].rm_so < cur_idx) { pmatch[reg_num].rm_eo = cur_idx; @@ -2195,6 +2204,7 @@ sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx, /* Return the next state to which the current state STATE will transit by accepting the current input byte, and update STATE_LOG if necessary. + Return NULL on failure. If STATE can accept a multibyte char/collating element/back reference update the destination of STATE_LOG. */ @@ -2395,7 +2405,7 @@ check_subexp_matching_top (re_match_context_t *mctx, re_node_set *cur_nodes, #if 0 /* Return the next state to which the current state STATE will transit by - accepting the current input byte. */ + accepting the current input byte. Return NULL on failure. */ static re_dfastate_t * transit_state_sb (reg_errcode_t *err, re_match_context_t *mctx, @@ -2817,7 +2827,8 @@ find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes, /* Check whether the node TOP_NODE at TOP_STR can arrive to the node LAST_NODE at LAST_STR. We record the path onto PATH since it will be heavily reused. - Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise. */ + Return REG_NOERROR if it can arrive, REG_NOMATCH if it cannot, + REG_ESPACE if memory is exhausted. */ static reg_errcode_t __attribute_warn_unused_result__ @@ -3433,7 +3444,8 @@ build_trtable (const re_dfa_t *dfa, re_dfastate_t *state) /* Group all nodes belonging to STATE into several destinations. Then for all destinations, set the nodes belonging to the destination to DESTS_NODE[i] and set the characters accepted by the destination - to DEST_CH[i]. This function return the number of destinations. */ + to DEST_CH[i]. Return the number of destinations if successful, + -1 on internal error. */ static Idx group_nodes_into_DFAstates (const re_dfa_t *dfa, const re_dfastate_t *state, @@ -4211,7 +4223,8 @@ match_ctx_add_subtop (re_match_context_t *mctx, Idx node, Idx str_idx) } /* Register the node NODE, whose type is OP_CLOSE_SUBEXP, and which matches - at STR_IDX, whose corresponding OP_OPEN_SUBEXP is SUB_TOP. */ + at STR_IDX, whose corresponding OP_OPEN_SUBEXP is SUB_TOP. + Return the new entry if successful, NULL if memory is exhausted. */ static re_sub_match_last_t * match_ctx_add_sublast (re_sub_match_top_t *subtop, Idx node, Idx str_idx) |