Warnings that make sense under newer gcc can cause spurious
failures under older gcc; it's nice to allow out-of-the-box
development on stable releases while still getting the benefit
of improved warning detection in bleeding-edge setups.
* configure.ac (nw): Disable gcc warnings that cause build
failures under RHEL 6.3.
* gnulib: Update to latest.
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
ChangeLog | 7 +++++++
configure.ac | 23 ++++++++++++++++++++++-
gnulib | 2 +-
3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index b369e83..c415f70 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-11-19 Eric Blake <ebl...@redhat.com>
+
+ build: avoid problematic gcc 4.4 warnings
+ * configure.ac (nw): Disable gcc warnings that cause build
+ failures under RHEL 6.3.
+ * gnulib: Update to latest.
+
2012-11-14 Paul Eggert <egg...@cs.ucla.edu>
doc: improve prehistory discussion
diff --git a/configure.ac b/configure.ac
index e986de2..2d7ceef 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,6 +75,7 @@ if test "$gl_gcc_warnings" = yes; then
[M4_cv_gcc_pragma_push_works=no])
CFLAGS=$save_CFLAGS])
+ # This, $nw, is the list of warnings we disable.
nw=
nw="$nw -Waggregate-return" # K&R is anachronistic
nw="$nw -Wtraditional-conversion" # K&R is anachronistic
@@ -87,7 +88,27 @@ if test "$gl_gcc_warnings" = yes; then
nw="$nw -Wsign-conversion" # Too many warnings for now
nw="$nw -Wcast-qual" # Too many warnings for now
nw="$nw -Wswitch-enum" # Too many warnings for now
- # This, $nw, is the list of warnings we disable.
+ # gcc 4.4.6 complains enum-compare is C++ only; gcc 4.7.0 implies it in -Wall
+ nw="$nw -Wenum-compare"
+
+ # Gnulib uses '#pragma GCC diagnostic push' to silence some
+ # warnings, but older gcc doesn't support this.
+ AC_CACHE_CHECK([whether pragma GCC diagnostic push works],
+ [M4_cv_gcc_pragma_push_works], [
+ save_CFLAGS=$CFLAGS
+ CFLAGS='-Wunknown-pragmas -Werror'
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+ #pragma GCC diagnostic push
+ #pragma GCC diagnostic pop
+ ]])],
+ [M4_cv_gcc_pragma_push_works=yes],
+ [M4_cv_gcc_pragma_push_works=no])
+ CFLAGS=$save_CFLAGS])
+ if test $M4_cv_gcc_pragma_push_works = no; then
+ nw="$nw -Wmissing-prototypes"
+ nw="$nw -Wmissing-declarations"
+ nw="$nw -Wunreachable-code"
+ fi
gl_MANYWARN_ALL_GCC([ws])
gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
diff --git a/gnulib b/gnulib
index 3a9002d..fd9f1ac 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 3a9002d3cc63da7110f133b1040d2d2b0aad8305
+Subproject commit fd9f1acededd74f8cd095e657528aa8fad183536
--
1.7.11.7
_______________________________________________
M4-patches mailing list
M4-patches@gnu.org
https://lists.gnu.org/mailman/listinfo/m4-patches
