ci: Test C++ compatibility mode

.gitlab-ci.yml

@@ -5,6 +5,7 @@ default:
 stages:
   - pre-build
   - build
+  - test
   - static-analysis
   - pages
 
@@ -82,6 +83,13 @@ linux-cmake-make-old:
   script:
     - sh build/gitlab-ci cmake "Unix Makefiles" Release
 
+gcc-cpp-compat:
+  stage: test
+  rules:
+    - if: '$CI_PROJECT_PATH == "libtiff/libtiff"'
+  script:
+    - sh build/gitlab-ci cmake "Ninja" Debug cxxcompat
+
 freebsd15-release:
   stage: build
   rules:
@@ -98,6 +106,14 @@ freebsd15-debug:
   script:
     - sh build/gitlab-ci cmake Ninja Debug
 
+clang-cpp-compat:
+  stage: test
+  rules:
+    - if: '$CI_PROJECT_PATH == "libtiff/libtiff"'
+  tags: [freebsd15]
+  script:
+    - sh build/gitlab-ci cmake Ninja Debug cxxcompat
+
 macos26-release:
   stage: build
   rules:

build/gitlab-ci

@@ -49,11 +49,13 @@ cmake_build()
     para3=`echo "$3" | sed 's/./\L&/g'`
     if [ "$para3" = "static" ]; then
         opts2="-DBUILD_SHARED_LIBS:BOOL=OFF"
+    elif [ "$para3" = "cxxcompat" ]; then
+        opts2="-Dcxx-compat-mode:BOOL=ON"
     else
         opts2=""
     fi
     echo "Running cmake -G "$1" -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE="$2" -DCMAKE_INSTALL_PREFIX=../cmake-install ${opts} ${opts2} .."
-    cmake -G "$1" -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE="$2" -DCMAKE_INSTALL_PREFIX=../cmake-install -DCMAKE_C_FLAGS="-Wall -Wextra -Werror" ${opts} ${opts2}  ..
+    cmake -G "$1" -DCMAKE_UNITY_BUILD=ON -DCMAKE_BUILD_TYPE="$2" -DCMAKE_INSTALL_PREFIX=../cmake-install -DCMAKE_C_FLAGS="-Wall -Wextra -Werror" -Dcxx-compat-warnings=ON ${opts} ${opts2} ..
     $COVERITY_BUILD cmake --build .
     cmake --build . --target install
     ctest -V