CI: add MSAN, TSAN and UBSAN Sanitizers

MemorySanitizer (MSan) is a detector of uninitialized memory reads in C/C++ programs.
Uninitialized values occur when stack- or heap-allocated memory is read before
it is written.

ThreadSanitizer is a tool that detects data races.

UndefinedBehaviorSanitizer (UBSan) is a fast undefined behavior detector. UBSan
catches various kinds of undefined behavior, for example:
- Using misaligned or null pointer
- Signed integer overflow
- Conversion to, from, or between floating-point types which would overflow the
  destination

The llvm.org states that Sanitizers have found thousands of bugs everywhere.
Sanitizers running during CI can prevent bugs from taking up residence. They
are helper tools to maintain bugs out.

1 files changed, 37 insertions, 0 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 91b9deec4..fbf97c4b1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,6 +2,7 @@ image: claudioandre/settings:job-502.6_fedora.dev  # temporarily pinned to old t
 stages:
   - build
   - test
+  - extra
   - delivery
 
 .Log files: &log_files  [./*.log, _build/meson-logs/]
@@ -195,3 +196,39 @@ packaging:
     name: review/$CI_COMMIT_REF_NAME
     url: https://gitlab.gnome.org/$CI_PROJECT_PATH/-/jobs/$CI_JOB_ID/artifacts/raw/${BUNDLE}
   when: manual
+
+##
+# Stage: Extra
+#
+# Runs the sanitizers [thread, undefined, memory].
+##
+.sanitizer: &sanitizer
+  <<: *save_build_logs
+  stage: extra
+  allow_failure: true
+
+  script:
+    - *environment_information
+    - *build_procedure
+
+    - echo "== Testing =="
+    - ninja -C _build test
+
+tsan:
+  <<: *sanitizer
+  variables:
+    BUILD_OPTS: "-Db_sanitize=thread"
+  when: manual
+
+ubsan:
+  <<: *sanitizer
+  variables:
+    BUILD_OPTS: "-Db_sanitize=undefined"
+  when: manual
+
+msan:
+  <<: *sanitizer
+  variables:
+    BUILD_OPTS: "-Db_sanitize=memory"
+    CC: "clang"
+  when : manual