ci: Add task testing windows with mingw

For now the task has been set to be manually triggered, as we are already
limited by the amount of CI time available for windows, particularly on cfbot.

Author: Melih Mutlu <m.melihmutlu@gmail.com>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CAGPVpCSKS9E0An4=e7ZDnme+y=WOcQFJYJegKO8kE9=gh8NJKQ@mail.gmail.com

.cirrus.yml

@@ -393,18 +393,13 @@ task:
     cores_script: src/tools/ci/cores_backtrace.sh macos "${HOME}/cores"
 
 
-task:
-  name: Windows - Server 2019, VS 2019 - Meson & ninja
-
+WINDOWS_ENVIRONMENT_BASE: &WINDOWS_ENVIRONMENT_BASE
   env:
     # Half the allowed per-user CPU cores
     CPUS: 4
-    TEST_JOBS: 8 # wild guess, data based value welcome
 
     # The default cirrus working dir is in a directory msbuild complains about
     CIRRUS_WORKING_DIR: "c:/cirrus"
-    # Avoid re-installing over and over
-    NO_TEMP_INSTALL: 1
     # git's tar doesn't deal with drive letters, see
     # https://postgr.es/m/b6782dc3-a7b0-ed56-175f-f8f54cb08d67%40dunslane.net
     TAR: "c:/windows/system32/tar.exe"
@@ -412,6 +407,22 @@ task:
     PG_TEST_USE_UNIX_SOCKETS: 1
     PG_REGRESS_SOCK_DIR: "c:/cirrus/"
 
+  sysinfo_script: |
+    chcp
+    systeminfo
+    powershell -Command get-psdrive -psprovider filesystem
+    set
+
+
+task:
+  name: Windows - Server 2019, VS 2019 - Meson & ninja
+  << : *WINDOWS_ENVIRONMENT_BASE
+
+  env:
+    TEST_JOBS: 8 # wild guess, data based value welcome
+    # Avoid re-installing over and over
+    NO_TEMP_INSTALL: 1
+
     # startcreate_script starts a postgres instance that we don't want to get
     # killed at the end of that script (it's stopped in stop_script). Can't
     # trivially use background_scripts because a) need pg_ctl's dropping of
@@ -435,19 +446,13 @@ task:
     cpu: $CPUS
     memory: 4G
 
-  sysinfo_script: |
-    chcp
-    systeminfo
-    powershell -Command get-psdrive -psprovider filesystem
-    set
-
   setup_additional_packages_script: |
     REM choco install -y --no-progress ...
 
   # Use /DEBUG:FASTLINK to avoid high memory usage during linking
   configure_script: |
     vcvarsall x64
-    meson setup --backend ninja --buildtype debug -Dc_link_args=/DEBUG:FASTLINK -Dcassert=true -Db_pch=true -Dssl=openssl -Dextra_lib_dirs=c:\openssl\1.1\lib -Dextra_include_dirs=c:\openssl\1.1\include -DTAR=c:/windows/system32/tar.exe -DPG_TEST_EXTRA="%PG_TEST_EXTRA%" build
+    meson setup --backend ninja --buildtype debug -Dc_link_args=/DEBUG:FASTLINK -Dcassert=true -Db_pch=true -Dssl=openssl -Dextra_lib_dirs=c:\openssl\1.1\lib -Dextra_include_dirs=c:\openssl\1.1\include -DTAR=%TAR% -DPG_TEST_EXTRA="%PG_TEST_EXTRA%" build
 
   build_script: |
     vcvarsall x64
@@ -464,6 +469,66 @@ task:
       type: text/plain
 
 
+task:
+  << : *WINDOWS_ENVIRONMENT_BASE
+  name: Windows - Server 2019, MinGW64 - Meson
+
+  # due to resource constraints we don't run this task by default for now
+  trigger_type: manual
+  # worth using only_if despite being manual, otherwise this task will show up
+  # when e.g. ci-os-only: linux is used.
+  only_if: $CIRRUS_CHANGE_MESSAGE !=~ '.*\nci-os-only:.*' || $CIRRUS_CHANGE_MESSAGE =~ '.*\nci-os-only:[^\n]*mingw.*'
+
+  windows_container:
+    image: $CONTAINER_REPO/windows_ci_mingw64:latest
+    cpu: $CPUS
+    memory: 4G
+
+  env:
+    TEST_JOBS: 4 # higher concurrency causes occasional failures
+    CCACHE_DIR: C:/msys64/ccache
+    CCACHE_MAXSIZE: "500M"
+    CCACHE_SLOPPINESS: pch_defines,time_macros
+    CCACHE_DEPEND: 1
+    # for some reason mingw plpython cannot find it's installation without this
+    PYTHONHOME: C:/msys64/ucrt64
+    # prevents MSYS bash from resetting error mode
+    MSYS: winjitdebug
+    # Start bash in current working directory
+    CHERE_INVOKING: 1
+    BASH: C:\msys64\usr\bin\bash.exe -l
+
+  ccache_cache:
+    folder: ${CCACHE_DIR}
+
+  setup_additional_packages_script: |
+    REM C:\msys64\usr\bin\pacman.exe -S --noconfirm ...
+
+  mingw_info_script: |
+    %BASH% -c "where gcc"
+    %BASH% -c "gcc --version"
+    %BASH% -c "where perl"
+    %BASH% -c "perl --version"
+
+  # disable -Dnls as the number of files it creates cause a noticable slowdown
+  configure_script: |
+    %BASH% -c "meson setup -Ddebug=true -Doptimization=g -Dcassert=true -Db_pch=true -Dnls=disabled -DTAR=%TAR% build"
+
+  build_script: |
+    %BASH% -c "ninja -C build"
+
+  upload_caches: ccache
+
+  test_world_script: |
+    %BASH% -c "meson test %MTEST_ARGS% --num-processes %TEST_JOBS%"
+
+  on_failure:
+    <<: *on_failure_meson
+    crashlog_artifacts:
+      path: "crashlog-*.txt"
+      type: text/plain
+
+
 task:
   name: CompilerWarnings
 

src/tools/ci/README

@@ -61,7 +61,7 @@ Controlling CI via commit messages
 The behavior of CI can be controlled by special content in commit
 messages. Currently the following controls are available:
 
-- ci-os-only: {(freebsd|linux|macos|windows)}
+- ci-os-only: {(freebsd|linux|macos|windows|mingw)}
 
   Only runs CI on operating systems specified. This can be useful when
   addressing portability issues affecting only a subset of platforms.