From 26432ac18342662bb9c793d1a64fa40e00c4b909 Mon Sep 17 00:00:00 2001
From: Norihiro Tanaka <address@hidden>
Date: Sat, 10 Nov 2018 08:25:28 +0900
Subject: [PATCH 2/3] dfa: clearly copy the members of struct DFA

When superset of a dfa is build, all members of original DFA are copied,
and values which are different from original are changed only.  This
change clearfies members should be copied.

* lib/dfa.c (maybe_disable_superset_dfa): Do it.
(dfasyntax): No longer initialize here.
(dfacopysyntax): Copy syntax from struct DFA to another.
(dfassbuild): Clearly copy the members of struct DFA
(dfaalloc): Initialize generated struct.
* lib/dfa.h (dfacopysyntax): Add prototype.
---
 lib/dfa.c |   59 ++++++++++++++++++++++++++++++++++++++---------------------
 lib/dfa.h |    5 +++++
 2 files changed, 43 insertions(+), 21 deletions(-)

diff --git a/lib/dfa.c b/lib/dfa.c
index 4b5c9bb..a761a26 100644
--- a/lib/dfa.c
+++ b/lib/dfa.c
@@ -886,6 +886,23 @@ char_context (struct dfa const *dfa, unsigned char c)
   return CTX_NONE;
 }
 
+/* Copy the syntax settings from one dfa instance to another.
+   Saves considerable computation time if compiling many regular expressions
+   based on the same setting.  */
+void
+dfacopysyntax (struct dfa *to, const struct dfa *from)
+{
+  to->dfaexec = from->dfaexec;
+  to->simple_locale = from->simple_locale;
+  to->localeinfo = from->localeinfo;
+
+  to->fast = from->fast;
+
+  to->canychar = from->canychar;
+  to->lex.cur_mb_len = from->lex.cur_mb_len;
+  to->syntax = from->syntax;
+}
+
 /* Set a bit in the charclass for the given wchar_t.  Do nothing if WC
    is represented by a multi-byte sequence.  Even for MB_CUR_MAX == 1,
    this may happen when folding case in weird Turkish locales where
@@ -3669,31 +3686,32 @@ dfassbuild (struct dfa *d)
 {
   struct dfa *sup = dfaalloc ();
 
-  *sup = *d;
+  dfacopysyntax (sup, d);
+
   sup->localeinfo.multibyte = false;
   sup->dfaexec = dfaexec_sb;
-  sup->multibyte_prop = NULL;
-  sup->superset = NULL;
-  sup->states = NULL;
-  sup->sindex = 0;
-  sup->constraints = NULL;
-  sup->separates = NULL;
-  sup->follows = NULL;
-  sup->tralloc = 0;
-  sup->trans = NULL;
-  sup->fails = NULL;
-  sup->success = NULL;
-  sup->newlines = NULL;
-
-  sup->charclasses = xnmalloc (sup->calloc, sizeof *sup->charclasses);
-  if (d->cindex)
+
+  sup->depth = d->depth;
+  sup->nleaves = d->nleaves;
+  sup->nregexps = d->nregexps;
+
+  if (d->cindex > 0)
     {
-      memcpy (sup->charclasses, d->charclasses,
-              d->cindex * sizeof *sup->charclasses);
+      sup->cindex = d->cindex;
+      sup->calloc = d->cindex;
+
+      sup->charclasses = xnmalloc (sup->calloc, sizeof *sup->charclasses);
+
+      memcpy (sup->charclasses, d->charclasses, sup->cindex * sizeof *sup->charclasses);
+
+      for (size_t i = 0; i < 5; i++)
+        sup->utf8_anychar_classes[i] = d->utf8_anychar_classes[i];
+
+      sup->canychar = d->canychar;
     }
 
-  sup->tokens = xnmalloc (d->tindex, 2 * sizeof *sup->tokens);
   sup->talloc = d->tindex * 2;
+  sup->tokens = xnmalloc (sup->talloc, sizeof *sup->tokens);
 
   bool have_achar = false;
   bool have_nchar = false;
@@ -4301,7 +4319,7 @@ dfamustfree (struct dfamust *dm)
 struct dfa *
 dfaalloc (void)
 {
-  return xmalloc (sizeof (struct dfa));
+  return xzalloc (sizeof (struct dfa));
 }
 
 /* Initialize DFA.  */
@@ -4309,7 +4327,6 @@ void
 dfasyntax (struct dfa *dfa, struct localeinfo const *linfo,
            reg_syntax_t bits, int dfaopts)
 {
-  memset (dfa, 0, offsetof (struct dfa, dfaexec));
   dfa->dfaexec = linfo->multibyte ? dfaexec_mb : dfaexec_sb;
   dfa->simple_locale = using_simple_locale (linfo->multibyte);
   dfa->localeinfo = *linfo;
diff --git a/lib/dfa.h b/lib/dfa.h
index fea815d..cb9d8dc 100644
--- a/lib/dfa.h
+++ b/lib/dfa.h
@@ -100,6 +100,11 @@ extern struct dfa *dfasuperset (struct dfa const *d) _GL_ATTRIBUTE_PURE;
 /* The DFA is likely to be fast.  */
 extern bool dfaisfast (struct dfa const *) _GL_ATTRIBUTE_PURE;
 
+/* Copy the syntax settings from one dfa instance to another.
+   Saves considerable computation time if compiling many regular expressions
+   based on the same setting.  */
+extern void dfacopysyntax (struct dfa *to, const struct dfa *from);
+
 /* Free the storage held by the components of a struct dfa. */
 extern void dfafree (struct dfa *);
 
-- 
1.7.1