enable compiler warnings for gnulib-tests

[Eric Blake]

OK to commit?  We build lib using gcc warnings, but not gnulib-tests; it is 
nicer to treat all gnulib files equally.  Right now, many of the gnulib tests 
are quite noisy with coreutils' set of warnings, that will involve a series of 
patches to gnulib to clean up.

Meanwhile, I was seeing multiple instances of warnings like this when using 
cygwin's gcc 4.3.4:

  CC       mbswidth.o
cc1: warning: -funit-at-a-time is required for inlining of functions that are 
only called once [-Wdisabled-optimization]

as well as crud not ignored by git.

>From 057a3db6d91933b698f6d9cc81f41c81af7db01a Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Wed, 21 Oct 2009 11:27:29 -0600
Subject: [PATCH] maint: turn on compiler warnings for gnulib tests

* gnulib-tests/Makefile.am (AM_CFLAGS): Add WARN_CFLAGS.
* configure.ac (enable-gcc-warnings): Also use -funit-at-a-time,
to silence gcc 4.3.4 -Wdisabled-optimization.
* .gitignore: Ignore some more files.
---
 .gitignore               |    3 +++
 configure.ac             |    1 +
 gnulib-tests/Makefile.am |    2 ++
 3 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/.gitignore b/.gitignore
index 1116620..f6b6859 100644
--- a/.gitignore
+++ b/.gitignore
@@ -47,11 +47,13 @@ lib/arpa
 lib/binary-io.h
 lib/charset.alias
 lib/configmake.h
+lib/glthread
 lib/libcoreutils.a
 lib/printf.c
 lib/progname.c
 lib/progname.h
 lib/selinux
+lib/unistr
 lib/uniwidth
 m4/.cvsignore
 m4/.gitignore
@@ -71,4 +73,5 @@ po/stamp-po
 src/version.c
 src/version.h
 stamp-h1
+tests/test-suite.log
 tests/*/*.log
diff --git a/configure.ac b/configure.ac
index 4902fea..3efc819 100644
--- a/configure.ac
+++ b/configure.ac
@@ -106,6 +106,7 @@ if test "$gl_gcc_warnings" = yes; then
   gl_WARN_ADD([-Wno-logical-op])

   gl_WARN_ADD([-fdiagnostics-show-option])
+  gl_WARN_ADD([-funit-at-a-time])

   AC_SUBST([WARN_CFLAGS])

diff --git a/gnulib-tests/Makefile.am b/gnulib-tests/Makefile.am
index 6635f70..494786f 100644
--- a/gnulib-tests/Makefile.am
+++ b/gnulib-tests/Makefile.am
@@ -1 +1,3 @@
 include gnulib.mk
+
+AM_CFLAGS = $(WARN_CFLAGS) # $(WERROR_CFLAGS)
-- 
1.6.4.2