dfa: make dfa.c fully thread-safe

This follows up on Zev Weiss’s recent patches to make the DFA code
thread-safe (Bug#24249).  It removes the remaining static
variables used by dfa.c.  These variables are locale-dependent, so
they would cause problems in multithreaded code where different
threads are in different locales (e.g., via uselocale).  I
abstracted most of the variables into a new localeinfo module.
* src/Makefile.am (grep_SOURCES): Add localeinfo.c.
(noinst_HEADERS): Add localeinfo.h.
* src/dfa.c: Include localeinfo.h.
(struct dfa): Remove multibyte member, as it is now part of
localeinfo.  New members simple_locale and localeinfo.
Put locale-related members at the end.
(mbrtowc_cache): Remove; now part of dfa->localeinfo.
(charclass_index): Rename back from dfa_charclass_index,
since it's private.
(unibyte_word_constituent): New arg DFA; use its sbctowc member.
(using_utf8, dfa_using_utf8, init_mbrtowc_cache, check_utf8):
Remove; now done by localeinfo members.  All uses changed.
(dfasyntax): New localeinfo arg.  Move to end to avoid forward decls.
Initialize the entire DFA.
(unibyte_c, check_unibyte_c): Remove; now in simple_locale member.
(using_simple_locale): Now takes bool instead of DFA.
Do the locale check here, rather than in the caller,
as the result is now cached in dfa->simple_locale.
(dfaalloc): Just allocate the DFA.  dfasyntax now initializes it.
* src/dfa.h: Add forward decl of struct localeinfo.
Adjust to new dfa.c API.
* src/dfasearch.c (localeinfo): New var, replacing former static
vars like mbrtowc_cache.
* src/localeinfo.c, src/localeinfo.h: New files.
* src/search.h: Include localeinfo.h.
(localeinfo): New decl.
* src/searchutils.c (mbclen_cache, build_mbclen_cache):
Remove.  All uses changed to localeinfo.
* tests/Makefile.am (dfa_match_aux_LDADD): Add localeinfo.o.
* tests/dfa-match-aux.c: Include localeinfo.h.
(main): Adjust to changes in DFA API.

1 files changed, 3 insertions, 4 deletions

diff --git a/src/search.h b/src/search.h
index 7dc19408..431a67da 100644
--- a/src/search.h
+++ b/src/search.h
@@ -33,6 +33,7 @@
 #include "dfa.h"
 #include "kwset.h"
 #include "xalloc.h"
+#include "localeinfo.h"
 
 _GL_INLINE_HEADER_BEGIN
 #ifndef SEARCH_INLINE
@@ -47,14 +48,12 @@ typedef signed char mb_len_map_t;
 
 /* searchutils.c */
 extern void kwsinit (kwset_t *);
-
-extern void build_mbclen_cache (void);
-extern size_t mbclen_cache[];
 extern ptrdiff_t mb_goback (char const **, char const *, char const *);
 extern wint_t mb_prev_wc (char const *, char const *, char const *);
 extern wint_t mb_next_wc (char const *, char const *);
 
 /* dfasearch.c */
+extern struct localeinfo localeinfo;
 extern void GEAcompile (char const *, size_t, reg_syntax_t);
 extern size_t EGexecute (char *, size_t, size_t *, char const *);
 
@@ -73,7 +72,7 @@ extern size_t Pexecute (char *, size_t, size_t *, char const *);
 SEARCH_INLINE size_t
 mb_clen (char const *s, size_t n, mbstate_t *mbs)
 {
-  size_t len = mbclen_cache[to_uchar (*s)];
+  size_t len = localeinfo.sbclen[to_uchar (*s)];
   return len == (size_t) -2 ? mbrlen (s, n, mbs) : len;
 }