CI build_examples.sh: Fail on warnings, even with -Wno-error

make/build_examples.sh

@@ -12,24 +12,42 @@
 EXAMPLE_NUM=1
 RESULT=0
 
+RESULT_WARNINGS=22  # magic number result code for "warnings found"
+
 set -e
 
 for example in ${IDF_PATH}/examples/*; do
     [ -f ${example}/Makefile ] || continue
     echo "Building ${example} as ${EXAMPLE_NUM}..."
-    mkdir ${EXAMPLE_NUM}
-    cp -r ${example} ${EXAMPLE_NUM}
-    pushd ${EXAMPLE_NUM}/`basename ${example}`
+    mkdir -p example_builds/${EXAMPLE_NUM}
+    cp -r ${example} example_builds/${EXAMPLE_NUM}
+    pushd example_builds/${EXAMPLE_NUM}/`basename ${example}`
 
    # be stricter in the CI build than the default IDF settings
    export EXTRA_CFLAGS="-Werror -Werror=deprecated-declarations"
    export EXTRA_CXXFLAGS=${EXTRA_CFLAGS}
 
-   # build non-verbose first, only build verbose if there's an error
-    (make clean defconfig && make all ) || (RESULT=$?; make V=1)
+   # build non-verbose first
+   BUILDLOG=$(mktemp -t examplebuild.XXXX.log)
+   (
+       set -e
+       make clean defconfig
+       make all 2>&1 | tee $BUILDLOG
+    ) || (RESULT=$?; make V=1) # only build verbose if there's an error
     popd
     EXAMPLE_NUM=$(( $EXAMPLE_NUM + 1 ))
+
+    if [ $RESULT -eq 0 ] && grep -q ": warning:" $BUILDLOG; then
+        echo "Build will fail, due to warnings in this example"
+        RESULT=$RESULT_WARNINGS
+    fi
+
+    rm -f $BUILDLOG
 done
 
+if [ $RESULT -eq $RESULT_WARNINGS ]; then
+    echo "Build would have passed, except for warnings."
+fi
+
 exit $RESULT