[PATCH 3/4] regex: tell compiler there’s at most 256 arcs out

[Paul Eggert]

Partly this is to help the reader (and maybe help GCC);
partly this is to pacify Coverity.
* lib/regex_internal.h: Include verify.h.
* lib/regexec.c (group_nodes_into_DFAstates):
Tell the compiler that ndests cannot exceed SBC_MAX.
* modules/regex (Depends-on): Add ‘verify’.
---
 ChangeLog            | 8 ++++++++
 lib/regex_internal.h | 1 +
 lib/regexec.c        | 1 +
 modules/regex        | 1 +
 4 files changed, 11 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 4f96c8cbf..360973ba4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2019-10-09  Paul Eggert  <address@hidden>
 
+       regex: tell compiler there’s at most 256 arcs out
+       Partly this is to help the reader (and maybe help GCC);
+       partly this is to pacify Coverity.
+       * lib/regex_internal.h: Include verify.h.
+       * lib/regexec.c (group_nodes_into_DFAstates):
+       Tell the compiler that ndests cannot exceed SBC_MAX.
+       * modules/regex (Depends-on): Add ‘verify’.
+
        regex: simplify by assuming C99
        * config/srclist.txt: Comment out regex_internal.h and regexec.c
        temporarily.
diff --git a/lib/regex_internal.h b/lib/regex_internal.h
index 9c0e1f1d1..b6eeba32d 100644
--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -34,6 +34,7 @@
 #include <stdint.h>
 
 #include <intprops.h>
+#include <verify.h>
 
 #ifdef _LIBC
 # include <libc-lock.h>
diff --git a/lib/regexec.c b/lib/regexec.c
index f7d2b5b20..0d32e0139 100644
--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -3684,6 +3684,7 @@ group_nodes_into_DFAstates (const re_dfa_t *dfa, const 
re_dfastate_t *state,
          bitset_empty (accepts);
        }
     }
+  assume (ndests <= SBC_MAX);
   return ndests;
  error_return:
   for (j = 0; j < ndests; ++j)
diff --git a/modules/regex b/modules/regex
index 7f50916ce..dbfd37982 100644
--- a/modules/regex
+++ b/modules/regex
@@ -30,6 +30,7 @@ mbsinit         [test $ac_use_included_regex = yes]
 nl_langinfo     [test $ac_use_included_regex = yes]
 stdbool         [test $ac_use_included_regex = yes]
 stdint          [test $ac_use_included_regex = yes]
+verify          [test $ac_use_included_regex = yes]
 wchar           [test $ac_use_included_regex = yes]
 wcrtomb         [test $ac_use_included_regex = yes]
 wctype-h        [test $ac_use_included_regex = yes]
-- 
2.21.0