use strict CFLAGS to catch common mistakes in ci pipeline

A number of common coding errors are missed by the compiler.
They turn up only after release once packages are build with full CFLAGS.

Adjust the gitlab CI to catch such errors:

-Wall enables a number of diagnostics

-Wno-deprecated-declarations will hide a bogus warning.
As long as an API exists it can be used. Noone beside a curious developer
will actually take the time to do research and look for the replacment.
In the wild this warning is just noise in the build log.

-Werror=implicit-function-declaration will point out missing includes.
In case such errors are not fixed, the resulting code will assume int
for function arguments and function return values.

-Werror=return-type will point out incorrect return values. The caller
will most likely receive just garbage.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

2 files changed, 9 insertions, 2 deletions

diff --git a/ci/build_libs.sh b/ci/build_libs.sh
index 2853951..e85c765 100644
--- a/ci/build_libs.sh
+++ b/ci/build_libs.sh
@@ -16,6 +16,13 @@ AUTOGEN_OPTIONS="
   --enable-gtk-doc
 "
 
+CFLAGS="
+  -Wall
+  -Wno-deprecated-declarations
+  -Werror=implicit-function-declaration
+  -Werror=return-type
+"
+
 # list of git repos in build order
 REPOS="${XFCE_BASE}/xfce/xfce4-dev-tools.git
   ${XFCE_BASE}/xfce/libxfce4util.git
@@ -34,7 +41,7 @@ for URL in ${REPOS}; do
     TAG=$(git describe --abbrev=0 --match "$NAME*" 2>/dev/null)
     echo "--- Building $NAME ($TAG) ---"
     git checkout -b build-$TAG $TAG
-    ./autogen.sh $AUTOGEN_OPTIONS
+    env "CFLAGS=${CFLAGS}" ./autogen.sh $AUTOGEN_OPTIONS
     make -j${NPROC:-$(nproc)}
     make install
     echo "$(pwd): $(git describe)" >> /tmp/xfce_build_version_info.txt
diff --git a/ci/build_project.yml b/ci/build_project.yml
index bfccb06..42a890d 100644
--- a/ci/build_project.yml
+++ b/ci/build_project.yml
@@ -33,7 +33,7 @@ distcheck:
 
 .make:
   before_script:
-    - ./autogen.sh
+    - env "CFLAGS=-Wall -Wno-deprecated-declarations -Werror=implicit-function-declaration -Werror=return-type" ./autogen.sh
   rules:
     # If there are changes to .po, never run. We also check
     # BEFORE_SHA to see if it is zeros, in which case we are