Enabled -Werror on some Travis builds.

This will cause any compiler warnings to be treated as errors and fail
the CI build. A couple of warnings are grandfathered in until they are
fixed in the code.

The -Werror switch can't be added to the CFLAGS on the configure command
because it causes some autoconf tests to fail. Instead, it's appended to
the existing flags at make time.

diff --git a/.travis.yml b/.travis.yml
index 3ed8491..9c122a7 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -170,18 +170,18 @@ script:
   - if [ "$CONFIG" = "stackprotect" ] ; then CFLAGS='-g -O0 -fstack-protector-all'; fi
   - if [ "$CONFIG" = "disable-nls" ] ; then CFLAGS='-Wall -Wextra -O3'; CONFIGURE_OPTS='--disable-nls'; fi
   - if [ "$CONFIG" = "clang6" ] ; then CFLAGS='-Wall -Wextra -O3'; export CC=clang-6.0; fi
-  - if [ "$CONFIG" = "clang8" ] ; then CFLAGS='-Wall -Wextra -O3'; export CC=clang-8; fi
-  - if [ "$CONFIG" = "gcc8" ] ; then CFLAGS='-Wall -Wextra -O3'; export CC=gcc-8; fi
+  - if [ "$CONFIG" = "clang8" ] ; then CFLAGS='-Wall -Wextra -Wno-error=switch -O3'; MAKE_OPTS="CFLAGS+=-Werror CFLAGS+=${CFLAGS// / CFLAGS+=}"; export CC=clang-8; fi
+  - if [ "$CONFIG" = "gcc8" ] ; then CFLAGS='-Wall -Wextra -Wno-error=switch -Wno-error=implicit-fallthrough -O3'; MAKE_OPTS="CFLAGS+=-Werror CFLAGS+=${CFLAGS// / CFLAGS+=}"; export CC=gcc-8; fi
   - if [ "$CONFIG" = "arm-cross" ] ; then CFLAGS='-Wall -Wextra -O3'; export CC=arm-linux-gnueabihf-gcc-4.8; CONFIGURE_OPTS='--host=arm-linux-gnueabihf'; fi
   - if [ "$CONFIG" = "musl" ] ; then CFLAGS='-Wall -Wextra -O3'; export CC=musl-gcc; CONFIGURE_OPTS='--disable-shared'; fi
   - if [ "$CONFIG" = "sanitize" ] ; then CFLAGS='-g -Wall -Wextra -fsanitize=address -fsanitize=undefined -fsanitize-address-use-after-scope'; export CC=clang-8; export ASAN_OPTIONS=strict_string_checks=1:detect_stack_use_after_return=1:check_initialization_order=1:strict_init_order=1:detect_leaks=1; fi
-  - if [ "$CONFIG" = "coverage" ] ; then cd "$HOME"/libexif-testsuite; CFLAGS=--coverage; CONFIGURE_OPTS="LDFLAGS=--coverage --with-failmalloc=$HOME/failmalloc/lib" ; fi
+  - if [ "$CONFIG" = "coverage" ] ; then cd "$HOME"/libexif-testsuite; CFLAGS=--coverage; CONFIGURE_OPTS="LDFLAGS=--coverage --with-failmalloc=$HOME/failmalloc/lib"; fi
   - ./configure --prefix="$HOME"/install --disable-dependency-tracking CFLAGS="$CFLAGS" $CONFIGURE_OPTS || { tail -n 300 config.log; false; }
 
-  - make V=1
+  - make V=1 $MAKE_OPTS
   # Skip tests when cross compiling.
-  - if [ "$CONFIG" != "arm-cross" ] ; then make V=1 check || { tail -n 300 test*/test-suite.log src/libexif/test*/test-suite.log; false; }; fi
-  - make V=1 install
+  - if [ "$CONFIG" != "arm-cross" ] ; then make V=1 $MAKE_OPTS check || { tail -n 300 test*/test-suite.log src/libexif/test*/test-suite.log; false; }; fi
+  - make V=1 $MAKE_OPTS install
 
   - if [ "$CONFIG" = "coverage" ] ; then cd "$TRAVIS_BUILD_DIR"; fi