From d0345459737e9f4ee436fa3a19a076ac681db2a5 Mon Sep 17 00:00:00 2001
From: Paul Eggert <address@hidden>
Date: Tue, 16 Aug 2016 03:04:26 -0700
Subject: [PATCH 1/2] dfa: avoid uninitialized constants

Some compilers warn about 'static int const x;' on the grounds
that X should have an initializer.  Instead of worrying about
this, rewrite to avoid this sort of thing.
* src/dfa.c (emptyset): New function.
(parse_bracket_exp): Use it instead of 'equal' and a zero constant.
* src/dfasearch.c (struct patterns): Remove tag 'patterns'.
(patterns0): Remove zero constant.
(GEAcompile): Use memset instead of the zero constant.
---
 src/dfa.c       | 13 +++++++++++--
 src/dfasearch.c |  8 +++-----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/dfa.c b/src/dfa.c
index b64a176..f970766 100644
--- a/src/dfa.c
+++ b/src/dfa.c
@@ -608,6 +608,16 @@ equal (charclass const s1, charclass const s2)
   return memcmp (s1, s2, sizeof (charclass)) == 0;
 }
 
+static bool
+emptyset (charclass const s)
+{
+  charclass_word w = 0;
+  int i;
+  for (i = 0; i < CHARCLASS_WORDS; i++)
+    w |= s[i];
+  return w == 0;
+}
+
 /* Ensure that the array addressed by PTR holds at least NITEMS +
    (PTR || !NITEMS) items.  Either return PTR, or reallocate the array
    and return its new address.  Although PTR may be null, the returned
@@ -1184,9 +1194,8 @@ parse_bracket_exp (void)
 
   if (dfa->multibyte)
     {
-      static charclass const zeroclass;
       work_mbc->invert = invert;
-      work_mbc->cset = equal (ccl, zeroclass) ? -1 : charclass_index (ccl);
+      work_mbc->cset = emptyset (ccl) ? -1 : charclass_index (ccl);
       return MBCSET;
     }
 
diff --git a/src/dfasearch.c b/src/dfasearch.c
index 9a523c8..222232c 100644
--- a/src/dfasearch.c
+++ b/src/dfasearch.c
@@ -38,15 +38,13 @@ static kwset_t kwset;
 static struct dfa *dfa;
 
 /* The Regex compiled patterns.  */
-static const struct patterns
+static struct
 {
   /* Regex compiled regexp. */
   struct re_pattern_buffer regexbuf;
   struct re_registers regs; /* This is here on account of a BRAIN-DEAD
                                address@hidden library interface in regex.c.  */
-} patterns0;
-
-static struct patterns *patterns;
+} *patterns;
 static size_t pcount;
 
 /* Number of compiled fixed strings known to exactly match the regexp.
@@ -153,7 +151,7 @@ GEAcompile (char const *pattern, size_t size, reg_syntax_t syntax_bits)
         }
 
       patterns = xnrealloc (patterns, pcount + 1, sizeof *patterns);
-      patterns[pcount] = patterns0;
+      memset (&patterns[pcount], 0, sizeof patterns[pcount]);
 
       char const *err = re_compile_pattern (p, len,
                                             &(patterns[pcount].regexbuf));
-- 
2.7.4