update to latest gnulib and clean-up

[Jim Meyering]

These changes fix typos, add explicit "extern" keywords
(preparing for...), add a syntax check to enforce scoping policy,
and update to the latest from gnulib:

>From 802f411c5c04a38dd5fa7bb2a3c2d9085a8669cc Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sun, 10 Apr 2011 09:49:22 +0200
Subject: [PATCH 1/4] maint: fix doubled-word typos in comments

* src/dfa.c (SUCCEEDS_IN_CONTEXT): Remove doubled "a".
* src/dfa.c (BACKREF): s/it it/it is/
---
 src/dfa.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/dfa.c b/src/dfa.c
index bdc3a7f..5f95ac9 100644
--- a/src/dfa.c
+++ b/src/dfa.c
@@ -104,7 +104,7 @@ typedef int charclass[CHARCLASS_INTS];

    Word-constituent characters are those that satisfy isalnum().

-   The macro SUCCEEDS_IN_CONTEXT determines whether a a given constraint
+   The macro SUCCEEDS_IN_CONTEXT determines whether a given constraint
    succeeds in a particular context.  Prevn is true if the previous character
    was a newline, currn is true if the lookahead character is a newline.
    Prevl and currl similarly depend upon whether the previous and current
@@ -152,7 +152,7 @@ typedef enum
                                    the empty string. */

   BACKREF,                     /* BACKREF is generated by \<digit>; it
-                                   it not completely handled.  If the scanner
+                                   is not completely handled.  If the scanner
                                    detects a transition on backref, it returns
                                    a kind of "semi-success" indicating that
                                    the match will have to be verified with
--
1.7.5.421.g9d34e


>From abcb2b51a6ecd30134074277a611f2dea71421c9 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Thu, 28 Apr 2011 10:12:11 +0200
Subject: [PATCH 2/4] maint: mark some function declarations as extern

* src/search.h: Add "extern" keyword to each function declaration.
---
 src/search.h |   19 +++++++++----------
 1 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/search.h b/src/search.h
index 5a05909..c48bbab 100644
--- a/src/search.h
+++ b/src/search.h
@@ -36,24 +36,23 @@
 #include "xalloc.h"

 /* searchutils.c */
-void kwsinit (kwset_t *);
+extern void kwsinit (kwset_t *);

 #if MBS_SUPPORT
-char * mbtolower (const char *, size_t *);
-bool is_mb_middle(const char **, const char *, const char *, size_t);
+extern char *mbtolower (const char *, size_t *);
+extern bool is_mb_middle (const char **, const char *, const char *, size_t);
 #endif

 /* dfasearch.c */
-void GEAcompile (char const *, size_t, reg_syntax_t);
-size_t EGexecute (char const *, size_t, size_t *, char const *);
+extern void GEAcompile (char const *, size_t, reg_syntax_t);
+extern size_t EGexecute (char const *, size_t, size_t *, char const *);

 /* kwsearch.c */
-void Fcompile (char const *, size_t);
-size_t Fexecute (char const *, size_t, size_t *, char const *);
+extern void Fcompile (char const *, size_t);
+extern size_t Fexecute (char const *, size_t, size_t *, char const *);

 /* pcresearch.c */
-void Pcompile (char const *, size_t);
-size_t Pexecute (char const *, size_t, size_t *, char const *);
-
+extern void Pcompile (char const *, size_t);
+extern size_t Pexecute (char const *, size_t, size_t *, char const *);

 #endif /* GREP_SEARCH_H */
--
1.7.5.421.g9d34e


>From 5468f6034610bb108d89e13dc24c833202ee7388 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Thu, 28 Apr 2011 10:20:43 +0200
Subject: [PATCH 3/4] maint: add the tight_scope syntax-checking rule

This ensures that the only externally scoped symbols are ones
that are explicitly marked as "extern" or white-listed like "main".
* src/Makefile.am (sc_tight_scope): New rule, copied from coreutils.
* cfg.mk (sc_tight_scope): Define, to hook to it from the top level.
---
 cfg.mk          |    4 ++++
 src/Makefile.am |   40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/cfg.mk b/cfg.mk
index 9b7b93d..035a299 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -54,6 +54,10 @@ sc_prohibit_emacs__indent_tabs_mode__setting:
        halt='use of emacs indent-tabs-mode: setting'                   \
          $(_sc_search_regexp)

+ALL_RECURSIVE_TARGETS = sc_tight_scope
+sc_tight_scope:
+       @$(MAKE) -s -C src $@
+
 update-copyright-env = \
   UPDATE_COPYRIGHT_USE_INTERVALS=1 \
   UPDATE_COPYRIGHT_MAX_LINE_LENGTH=79
diff --git a/src/Makefile.am b/src/Makefile.am
index 257472b..ec3e176 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -45,3 +45,43 @@ localedir = $(datadir)/locale
 AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib

 EXTRA_DIST = dosbuf.c
+
+# The following rule is not designed to be portable,
+# and relies on tools that not everyone has.
+
+# Most functions in src/*.c should have static scope.
+# Any that don't must be marked with `extern', but `main'
+# and `usage' are exceptions: they're always extern, but
+# do not need to be marked.  Also functions starting with __
+# are exempted due to possibly being added by the compiler
+# (when compiled as a shared library for example).
+#
+# The second nm|grep checks for file-scope variables with `extern' scope.
+.PHONY: sc_tight_scope
+sc_tight_scope: $(bin_PROGRAMS)
+       @t=exceptions-$$$$;                                             \
+       trap 's=$$?; rm -f $$t; exit $$s' 0;                            \
+       for sig in 1 2 3 13 15; do                                      \
+         eval "trap 'v=`expr $$sig + 128`; (exit $$v); exit $$v' $$sig"; \
+       done;                                                           \
+       src=`for f in $(SOURCES); do                                    \
+              test -f $$f && d= || d=$(srcdir)/; echo $$d$$f; done`;   \
+       hdr=`for f in $(noinst_HEADERS); do                             \
+              test -f $$f && d= || d=$(srcdir)/; echo $$d$$f; done`;   \
+       ( printf 'main\nusage\n_.*\n';                                  \
+         grep -h -A1 '^extern .*[^;]$$' $$src                          \
+           | grep -vE '^(extern |--)' | sed 's/ .*//';                 \
+         perl -lne '/^extern (?:struct |const |enum )?\S+ \**(\S*) \(/'\
+                 -e 'and print $$1' $$hdr;                             \
+       ) | sort -u | sed 's/^/^/;s/$$/$$/' > $$t;                      \
+       nm -e *.$(OBJEXT) | sed -n 's/.* T //p'                         \
+           | sed 's/^_//' | grep -Ev -f $$t                            \
+         && { echo the above functions should have static scope >&2;   \
+              exit 1; } || : ;                                         \
+       ( printf '^program_name$$\n';                                   \
+         perl -lne '/^extern .*?\**(\w+);/ and print "^$$1\$$"'        \
+           $$hdr *.h ) | sort -u > $$t;                                \
+       nm -e *.$(OBJEXT) | sed -n 's/.* [BD] //p'                      \
+           | sed 's/^_//' | grep -Ev -f $$t                            \
+         && { echo the above variables should have static scope >&2;   \
+              exit 1; } || :
--
1.7.5.421.g9d34e


>From 39761fdca7562c6229349fecde32b2989eddfd61 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Thu, 28 Apr 2011 10:21:03 +0200
Subject: [PATCH 4/4] build: update gnulib submodule to latest

---
 gnulib |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/gnulib b/gnulib
index 739321e..8585ce2 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 739321ef60661c7b51a4c7a3fa23957a4d9dbbc3
+Subproject commit 8585ce2ff5698c650ba5d5e3bb99763654ad62e8
--
1.7.5.421.g9d34e