CMake+CI: Colorize our compiler output.

As described at

https://medium.com/@alasher/colored-c-compiler-output-with-ninja-clang-gcc-10bfe7f2b949

both Clang and gcc generate colorized output when they detect a
terminal, but not for piped output, which is the case when using Ninja.
Add an ENABLE_COMPILER_COLOR_DIAGNOSTICS CMake option, and set it to
"ON" when we're using Ninja.

In the merge-req:ubuntu-gcc-ctest and merge-req:ubuntu-clang-other-tests
GitLab CI jobs, generate colorized HTML report artifacts using
ansi2html.

.gitlab-ci.yml

@@ -18,6 +18,8 @@ variables:
   GIT_DEPTH: "1"
   GIT_FETCH_EXTRA_FLAGS: "--depth=5000"
   CCACHE_DIR: "${CI_PROJECT_DIR}/ccache"
+  # Enable color output in CMake, Ninja, and other tools. https://bixense.com/clicolors/
+  CLICOLOR_FORCE: 1
 
 .build:
   stage: build
@@ -342,10 +344,14 @@ merge-req:ubuntu-gcc-ctest:
   script:
     # build-ubuntu puts us in `build`.
     - CC=gcc CXX=g++ cmake -DENABLE_EXTRA_COMPILER_WARNINGS=on -DCMAKE_EXPORT_COMPILE_COMMANDS=on -DENABLE_CCACHE=ON -G Ninja ..
-    - ninja
+    - script --command ninja --flush --quiet --return ../gcc_report.txt
+    - ansi2html < ../gcc_report.txt > ../gcc_report.html
     - ninja test-programs
     - chown -R user .
     - su user -c "ctest --parallel $(getconf _NPROCESSORS_ONLN) --force-new-ctest-process --verbose"
+  artifacts:
+    paths:
+      - gcc_report.html
 
 merge-req:ubuntu-clang-other-tests:
   extends: clang-11
@@ -363,14 +369,16 @@ merge-req:ubuntu-clang-other-tests:
     - if [[ -s "cppcheck_report.xml" ]]; then cppcheck-htmlreport --file cppcheck_report.xml  --report-dir . ; fi
     - cd build
     - cmake -DENABLE_EXTRA_COMPILER_WARNINGS=on -DENABLE_CHECKHF_CONFLICT=on -DCMAKE_EXPORT_COMPILE_COMMANDS=on -DENABLE_CCACHE=ON -G Ninja ..
-    - ninja
+    - script --command ninja --flush --quiet --return ../clang_report.txt
+    - ansi2html < ../clang_report.txt > ../clang_report.html
     - ./run/tshark -v
     - sh -c '[ ! -e ../tools/validate-clang-check.sh ] || ../tools/validate-clang-check.sh'
     - ninja checkAPI
   artifacts:
     paths:
-      - cppcheck_report.xml
+      - clang_report.html
       - cppcheck_report.html
+      - cppcheck_report.xml
       - item_calls_check.txt
       - tfs_check.txt
 

CMakeLists.txt

@@ -796,6 +796,18 @@ else() # ! MSVC
 		)
 	endif()
 
+	if(ENABLE_COMPILER_COLOR_DIAGNOSTICS)
+		if(CMAKE_C_COMPILER_ID MATCHES "Clang")
+			set(WIRESHARK_COMMON_FLAGS ${WIRESHARK_COMMON_FLAGS}
+				-fcolor-diagnostics
+			)
+		elseif(CMAKE_C_COMPILER_ID MATCHES "GNU")
+			set(WIRESHARK_COMMON_FLAGS ${WIRESHARK_COMMON_FLAGS}
+				-fdiagnostics-color=always
+			)
+		endif()
+	endif()
+
 	add_definitions(
 		-DG_DISABLE_DEPRECATED
 		-DG_DISABLE_SINGLE_INCLUDES

CMakeOptions.txt

@@ -55,6 +55,12 @@ option(ENABLE_FUZZER "Enable libFuzzer instrumentation for use with fuzzshark" O
 option(ENABLE_CHECKHF_CONFLICT "Enable hf conflict check for debugging (start-up may be slower)" OFF)
 option(ENABLE_CCACHE "Speed up compiling and linking using ccache if possible" OFF)
 
+if(CMAKE_GENERATOR STREQUAL "Ninja")
+	option(ENABLE_COMPILER_COLOR_DIAGNOSTICS "Always enable the compiler's color diagnostic output" ON)
+else()
+	option(ENABLE_COMPILER_COLOR_DIAGNOSTICS "Always enable the compiler's color diagnostic output" OFF)
+endif()
+
 if (WIN32)
 	option(ENABLE_LTO "Improves performance using Link time Optimization" ON)
 else()