ci: Test with ASan and rework CI matrix

Add CI tests with -fsanitize=address,undefined. This is a bit
complicated since our tests run through Python FFI and we have to

- link with -shared-libasan
- preload the ASan runtime
- disable LeakSanitizer beacuse of false positives from Python

Use a single matrix on POSIX with four human readable labels:

    posix (os, compiler, build_type, sanitizers)

Disable gcc on macOS which is just an alias for clang.

Remove the valgrind leakcheck test. This should be covered now
by testing with LeakSanitizer on static builds, including tests
like spectest_executable. The full test suite is only available
to shared library builds which habe to run without leak checks
for now.

Also rework the Windows matrix.

.github/workflows/ci.yml

@@ -27,86 +27,115 @@ jobs:
         CC: clang
         CXX: clang++
 
-  linux:
+  posix:
 
-    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        cmake_opts:
-          - '-DBUILD_SHARED_LIBS=YES'
-          - ''
-        compiler:
-          - c: 'clang'
-            cpp: 'clang++'
-            cflags: '-gdwarf-4'
-          - c: 'gcc'
-            cpp: 'g++'
-    env:
-       CMAKE_OPTIONS: ${{ matrix.cmake_opts }}
-       CC: ${{ matrix.compiler.c }}
-       CXX: ${{ matrix.compiler.cpp }}
-       CFLAGS: ${{ matrix.compiler.cflags }}
-       CXXFLAGS: ${{ matrix.compiler.cflags }}
+        os: [linux, macos]
+        cc: [clang, gcc]
+        build_type: [shared, static]
+        sanitizers: ['', ASan]
 
-    steps:
-    - uses: actions/checkout@v4
-    - name: Install valgrind
-      run: |
-         sudo apt update
-         sudo apt install -y valgrind
-    - name: Build and test
-      run: |
-         cmake $CMAKE_OPTIONS -DCMAKE_BUILD_TYPE=Debug -S . -B build
-         cmake --build build
-         ctest --test-dir build --output-on-failure
-         make leakcheck
+        include:
+          # Translate human readable labels
+          - os: 'linux'
+            image: 'ubuntu-latest'
+          - os: 'macos'
+            image: 'macos-latest'
+          - cc: 'clang'
+            cxx: 'clang++'
+          - cc: 'gcc'
+            cxx: 'g++'
+          - build_type: 'shared'
+            cmake_shared: 'YES'
+          - build_type: 'static'
+            cmake_shared: 'NO'
+          - sanitizers: 'ASan'
+            san_cflags: '-fsanitize=address,undefined -fno-sanitize-recover=all'
 
-  macos:
+          # When building shared libraries, they will be loaded
+          # dynamically from Python when testing. This means that
+          # we have to use a preloaded shared libasan.
+          - sanitizers: 'ASan'
+            os: 'linux'
+            cc: 'gcc'
+            build_type: 'shared'
+            test_env: 'LD_PRELOAD=$(gcc -print-file-name=libasan.so)'
+          - sanitizers: 'ASan'
+            os: 'linux'
+            cc: 'clang'
+            build_type: 'shared'
+            # clang defaults to -static-libsasn
+            asan_cflags: '-shared-libasan'
+            test_env: 'LD_PRELOAD=$(clang -print-file-name=libclang_rt.asan-x86_64.so)'
+
+          # We have to disable LeakSanitizer in shared library builds
+          # because we get false positives from Python.
+          - sanitizers: 'ASan'
+            build_type: 'shared'
+            asan_opts: 'detect_leaks=0'
+
+          # The static build can run with LeakSanitizer.
+          # gcc defaults to -shared-libasan and needs -static-libasan
+          - sanitizers: 'ASan'
+            cc: 'gcc'
+            build_type: 'static'
+            asan_cflags: '-static-libasan'
+
+        exclude:
+          # gcc is just an alias for clang on macOS
+          - os: 'macos'
+            cc: 'gcc'
+          # Shared libasan doesn't work with macOS system Python.
+          - os: 'macos'
+            sanitizers: 'ASan'
+            build_type: 'shared'
+
+    runs-on: ${{ matrix.image }}
 
-    runs-on: macos-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        cmake_opts:
-          - '-DBUILD_SHARED_LIBS=YES'
-          - ''
-        compiler:
-          - c: 'clang'
-            cpp: 'clang++'
-          - c: 'gcc'
-            cpp: 'g++'
     env:
-       CMAKE_OPTIONS: ${{ matrix.cmake_opts }}
-       CC: ${{ matrix.compiler.c }}
-       CXX: ${{ matrix.compiler.cpp }}
+       ASAN_OPTIONS: ${{ matrix.asan_opts }}
+       CC: ${{ matrix.cc }}
+       CXX: ${{ matrix.cxx }}
+       CFLAGS: '${{ matrix.san_cflags }} ${{ matrix.asan_cflags }}'
+       CXXFLAGS: '${{ matrix.san_cflags }} ${{ matrix.asan_cflags }}'
 
     steps:
     - uses: actions/checkout@v4
     - name: Build and test
       run: |
-         cmake $CMAKE_OPTIONS -DCMAKE_BUILD_TYPE=Debug -S . -B build
+         cmake \
+            -DBUILD_SHARED_LIBS=${{ matrix.cmake_shared }} \
+            -DCMAKE_BUILD_TYPE=Debug \
+            -S . -B build
          cmake --build build
-         ctest --test-dir build --output-on-failure
+         # https://github.com/actions/runner-images/issues/9491
+         sudo sysctl vm.mmap_rnd_bits=28 || true
+         ${{ matrix.test_env }} ctest --test-dir build --output-on-failure
 
   windows:
 
     runs-on: windows-latest
     strategy:
       fail-fast: false
       matrix:
-        cmake_opts:
-          - '-DBUILD_SHARED_LIBS=YES'
-          - ''
-    env:
-       CMAKE_OPTIONS: ${{ matrix.cmake_opts }}
+        build_type: [shared, static]
+        include:
+          - build_type: 'shared'
+            cmake_shared: 'YES'
+          - build_type: 'static'
+            cmake_shared: 'NO'
 
     steps:
     - uses: actions/checkout@v4
     - uses: ilammy/msvc-dev-cmd@v1
     - name: Build and test
       run: |
-        cmake %CMAKE_OPTIONS%  -DCMAKE_BUILD_TYPE=Debug -S . -B build
+        cmake ^
+            -DBUILD_SHARED_LIBS=${{ matrix.cmake_shared }} ^
+            -DCMAKE_BUILD_TYPE=Debug ^
+            -S . -B build
         cmake --build build
         ctest --test-dir build -C Debug --output-on-failure
       shell: cmd