From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Paul Eggert <eggert@cs.ucla.edu>,
bug-gnulib@gnu.org
Subject: [PATCH 1/3] posix: Remove alloca usage on regex set_regs
Date: Wed, 6 Jan 2021 15:17:05 -0300 [thread overview]
Message-ID: <20210106181707.1738066-1-adhemerval.zanella@linaro.org> (raw)
It replaces the regmatch_t with a dynarray list.
Checked on x86_64-linux-gnu.
---
posix/regexec.c | 62 ++++++++++++++++++++++++-------------------------
1 file changed, 31 insertions(+), 31 deletions(-)
diff --git a/posix/regexec.c b/posix/regexec.c
index b083342f77..5e22f90842 100644
--- a/posix/regexec.c
+++ b/posix/regexec.c
@@ -54,9 +54,6 @@ static Idx check_matching (re_match_context_t *mctx, bool fl_longest_match,
Idx *p_match_first);
static Idx check_halt_state_context (const re_match_context_t *mctx,
const re_dfastate_t *state, Idx idx);
-static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
- regmatch_t *prev_idx_match, Idx cur_node,
- 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,
@@ -1355,6 +1352,16 @@ pop_fail_stack (struct re_fail_stack_t *fs, Idx *pidx, Idx nregs,
return fs->stack[num].node;
}
+
+#define DYNARRAY_STRUCT regmatch_list
+#define DYNARRAY_ELEMENT regmatch_t
+#define DYNARRAY_PREFIX regmatch_list_
+#include <malloc/dynarray-skeleton.c>
+
+static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+ struct regmatch_list *prev_idx_match, Idx cur_node,
+ Idx cur_idx, Idx nmatch);
+
/* Set the positions where the subexpressions are starts/ends to registers
PMATCH.
Note: We assume that pmatch[0] is already set, and
@@ -1370,8 +1377,8 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
re_node_set eps_via_nodes;
struct re_fail_stack_t *fs;
struct re_fail_stack_t fs_body = { 0, 2, NULL };
- regmatch_t *prev_idx_match;
- bool prev_idx_match_malloced = false;
+ struct regmatch_list prev_idx_match;
+ regmatch_list_init (&prev_idx_match);
DEBUG_ASSERT (nmatch > 1);
DEBUG_ASSERT (mctx->state_log != NULL);
@@ -1388,23 +1395,18 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
cur_node = dfa->init_node;
re_node_set_init_empty (&eps_via_nodes);
- if (__libc_use_alloca (nmatch * sizeof (regmatch_t)))
- prev_idx_match = (regmatch_t *) alloca (nmatch * sizeof (regmatch_t));
- else
+ if (!regmatch_list_resize (&prev_idx_match, nmatch))
{
- prev_idx_match = re_malloc (regmatch_t, nmatch);
- if (prev_idx_match == NULL)
- {
- free_fail_stack_return (fs);
- return REG_ESPACE;
- }
- prev_idx_match_malloced = true;
+ regmatch_list_free (&prev_idx_match);
+ free_fail_stack_return (fs);
+ return REG_ESPACE;
}
- memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+ for (size_t i = 0; i < nmatch; i++)
+ *regmatch_list_at (&prev_idx_match, i) = pmatch[i];
for (idx = pmatch[0].rm_so; idx <= pmatch[0].rm_eo ;)
{
- update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch);
+ update_regs (dfa, pmatch, &prev_idx_match, cur_node, idx, nmatch);
if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node)
{
@@ -1417,8 +1419,7 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
if (reg_idx == nmatch)
{
re_node_set_free (&eps_via_nodes);
- if (prev_idx_match_malloced)
- re_free (prev_idx_match);
+ regmatch_list_free (&prev_idx_match);
return free_fail_stack_return (fs);
}
cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
@@ -1427,8 +1428,7 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
else
{
re_node_set_free (&eps_via_nodes);
- if (prev_idx_match_malloced)
- re_free (prev_idx_match);
+ regmatch_list_free (&prev_idx_match);
return REG_NOERROR;
}
}
@@ -1442,8 +1442,7 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
if (__glibc_unlikely (cur_node == -2))
{
re_node_set_free (&eps_via_nodes);
- if (prev_idx_match_malloced)
- re_free (prev_idx_match);
+ regmatch_list_free (&prev_idx_match);
free_fail_stack_return (fs);
return REG_ESPACE;
}
@@ -1453,15 +1452,13 @@ set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
else
{
re_node_set_free (&eps_via_nodes);
- if (prev_idx_match_malloced)
- re_free (prev_idx_match);
+ regmatch_list_free (&prev_idx_match);
return REG_NOMATCH;
}
}
}
re_node_set_free (&eps_via_nodes);
- if (prev_idx_match_malloced)
- re_free (prev_idx_match);
+ regmatch_list_free (&prev_idx_match);
return free_fail_stack_return (fs);
}
@@ -1483,7 +1480,8 @@ free_fail_stack_return (struct re_fail_stack_t *fs)
static void
update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
- regmatch_t *prev_idx_match, Idx cur_node, Idx cur_idx, Idx nmatch)
+ struct regmatch_list *prev_idx_match, Idx cur_node, Idx cur_idx,
+ Idx nmatch)
{
int type = dfa->nodes[cur_node].type;
if (type == OP_OPEN_SUBEXP)
@@ -1508,18 +1506,20 @@ update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
pmatch[reg_num].rm_eo = cur_idx;
/* This is a non-empty match or we are not inside an optional
subexpression. Accept this right away. */
- memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+ for (size_t i = 0; i < nmatch; i++)
+ *regmatch_list_at (prev_idx_match, i) = pmatch[i];
}
else
{
if (dfa->nodes[cur_node].opt_subexp
- && prev_idx_match[reg_num].rm_so != -1)
+ && regmatch_list_at (prev_idx_match, reg_num)->rm_so != -1)
/* We transited through an empty match for an optional
subexpression, like (a?)*, and this is not the subexp's
first match. Copy back the old content of the registers
so that matches of an inner subexpression are undone as
well, like in ((a?))*. */
- memcpy (pmatch, prev_idx_match, sizeof (regmatch_t) * nmatch);
+ memcpy (pmatch, regmatch_list_begin (prev_idx_match),
+ sizeof (regmatch_t) * nmatch);
else
/* We completed a subexpression, but it may be part of
an optional one, so do not update PREV_IDX_MATCH. */
--
2.25.1
next reply other threads:[~2021-01-06 18:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 18:17 Adhemerval Zanella [this message]
2021-01-06 18:17 ` [PATCH 2/3] posix: Remove alloca usage on regex build_trtable Adhemerval Zanella
2021-01-08 22:30 ` Paul Eggert
2021-01-11 12:31 ` Adhemerval Zanella
2021-01-06 18:17 ` [PATCH 3/3] posix: Remove alloca definition from regex Adhemerval Zanella
2021-01-09 1:20 ` Paul Eggert
2021-01-11 12:33 ` Adhemerval Zanella
2021-01-08 20:14 ` [PATCH 1/3] posix: Remove alloca usage on regex set_regs Paul Eggert
2021-01-11 12:35 ` Adhemerval Zanella
2021-01-09 1:24 ` Darshit Shah
2021-01-09 3:54 ` Paul Eggert
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