ci: remove mingw job #18580

Unnecessary CI builds increase the change of spurious failures, which are costly
noise. Of course, we should fix all legitimate bugs, but we also cannot
micro-manage every platform, so there needs to be a clear motivation for the CI
builds that we maintain.

Reasons against maintaining a mingw CI job:
1. The windows mingw build is slow.
2. Failures:
    - https://github.com/neovim/neovim/issues/18494
    - https://github.com/neovim/neovim/issues/18495
3. The mingw artifact is 10x bigger than the windows MSVC artifact:
   https://github.com/neovim/neovim/issues/10560
4. Our releases publish the MSVC (not mingw) artifact for Windows users:
   https://github.com/neovim/neovim/releases
5. Non-MSVCRT has limitations documented by libuv: http://docs.libuv.org/en/v1.x/process.html
   > On Windows file descriptors greater than 2 are available to the child process only if the child processes uses the MSVCRT runtime.

Closes https://github.com/neovim/neovim/issues/18551

11 files changed, 23 insertions, 195 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c60473d541..9a98c6097c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -236,21 +236,16 @@ jobs:
     env:
       DEPS_BUILD_DIR: ${{ format('{0}/nvim-deps', github.workspace) }}
       DEPS_PREFIX: ${{ format('{0}/nvim-deps/usr', github.workspace) }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        config: [ MINGW_64-gcov, MSVC_64 ]
-    name: windows (${{ matrix.config }})
+    name: windows (MSVC_64)
     steps:
       - uses: actions/checkout@v2
 
       - uses: actions/cache@v2
         with:
           path: ${{ env.DEPS_BUILD_DIR }}
-          key: ${{ matrix.config }}-${{ hashFiles('third-party\**') }}
+          key: ${{ hashFiles('third-party\**') }}
 
       - name: Run CI
         run: powershell ci\build.ps1
         env:
-          CONFIGURATION: ${{ matrix.config }}
+          CONFIGURATION: MSVC_64
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 409face71c..19c81ffcbe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -108,14 +108,7 @@ endif()
 
 option(ENABLE_LIBINTL "enable libintl" ON)
 option(ENABLE_LIBICONV "enable libiconv" ON)
-if (MINGW)
-  # Disable LTO by default as it may not compile
-  # See https://github.com/Alexpux/MINGW-packages/issues/3516
-  # and https://github.com/neovim/neovim/pull/8654#issuecomment-402316672
-  option(ENABLE_LTO "enable link time optimization" OFF)
-else()
-  option(ENABLE_LTO "enable link time optimization" ON)
-endif()
+option(ENABLE_LTO "enable link time optimization" ON)
 
 message(STATUS "CMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}")
 
@@ -322,10 +315,6 @@ else()
   endif()
 endif()
 
-if(MINGW)
-  # Use POSIX compatible stdio in Mingw
-  add_definitions(-D__USE_MINGW_ANSI_STDIO)
-endif()
 if(WIN32)
   # Windows Vista is the minimum supported version
   add_definitions(-D_WIN32_WINNT=0x0600)
diff --git a/ci/build.ps1 b/ci/build.ps1
index 533e5804c9..99f66f7de2 100644
--- a/ci/build.ps1
+++ b/ci/build.ps1
@@ -40,55 +40,14 @@ if (-Not (Test-Path -PathType container $env:DEPS_BUILD_DIR)) {
   write-host "cache dir $($env:DEPS_BUILD_DIR) size: $(Get-ChildItem $env:DEPS_BUILD_DIR -recurse | Measure-Object -property length -sum | Select -expand sum)"
 }
 
-if ($compiler -eq 'MINGW') {
-  if ($bits -eq 32) {
-    $arch = 'i686'
-  }
-  elseif ($bits -eq 64) {
-    $arch = 'x86_64'
-  }
-  if ($compileOption -eq 'gcov') {
-    $nvimCmakeVars['USE_GCOV'] = 'ON'
-    $uploadToCodecov = $true
-    $env:GCOV = "C:\msys64\mingw$bits\bin\gcov"
-
-    # Setup/build Lua coverage.
-    $env:USE_LUACOV = 1
-    $env:BUSTED_ARGS = "--coverage"
-  }
-  # These are native MinGW builds, but they use the toolchain inside
-  # MSYS2, this allows using all the dependencies and tools available
-  # in MSYS2, but we cannot build inside the MSYS2 shell.
-  $cmakeGenerator = 'Ninja'
-  $cmakeGeneratorArgs = '-v'
-  $mingwPackages = @('ninja', 'cmake', 'diffutils').ForEach({
-    "mingw-w64-$arch-$_"
-  })
-
-  # Add MinGW to the PATH
-  $env:PATH = "C:\msys64\mingw$bits\bin;$env:PATH"
-
-  # Avoid pacman "warning" which causes non-zero return code. https://github.com/open62541/open62541/issues/2068
-  & C:\msys64\usr\bin\mkdir -p /var/cache/pacman/pkg
-
-  # Build third-party dependencies
-  C:\msys64\usr\bin\bash -lc "pacman --verbose --noconfirm -Syu" ; exitIfFailed
-  # Update again in case updating pacman changes pacman.conf
-  C:\msys64\usr\bin\bash -lc "pacman --verbose --noconfirm -Syu" ; exitIfFailed
-  C:\msys64\usr\bin\bash -lc "pacman --verbose --noconfirm --needed -S $mingwPackages" ; exitIfFailed
-}
-elseif ($compiler -eq 'MSVC') {
-  $cmakeGeneratorArgs = '/verbosity:normal'
-  $cmakeGenerator = 'Visual Studio 16 2019'
-}
-
-if ($compiler -eq 'MSVC') {
-  $installationPath = vswhere.exe -latest -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath
-  if ($installationPath -and (test-path "$installationPath\Common7\Tools\vsdevcmd.bat")) {
-    & "${env:COMSPEC}" /s /c "`"$installationPath\Common7\Tools\vsdevcmd.bat`" -arch=x${bits} -no_logo && set" | foreach-object {
-      $name, $value = $_ -split '=', 2
-      set-content env:\"$name" $value
-    }
+$cmakeGeneratorArgs = '/verbosity:normal'
+$cmakeGenerator = 'Visual Studio 16 2019'
+
+$installationPath = vswhere.exe -latest -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath
+if ($installationPath -and (test-path "$installationPath\Common7\Tools\vsdevcmd.bat")) {
+  & "${env:COMSPEC}" /s /c "`"$installationPath\Common7\Tools\vsdevcmd.bat`" -arch=x${bits} -no_logo && set" | foreach-object {
+    $name, $value = $_ -split '=', 2
+    set-content env:\"$name" $value
   }
 }
 
@@ -111,14 +70,10 @@ function convertToCmakeArgs($vars) {
 }
 
 cd $env:DEPS_BUILD_DIR
-if ($compiler -eq 'MSVC') {
-  if ($bits -eq 32) {
-    cmake -G $cmakeGenerator -A Win32 $(convertToCmakeArgs($depsCmakeVars)) "$buildDir/third-party/" ; exitIfFailed
-  } else {
-    cmake -G $cmakeGenerator -A x64 $(convertToCmakeArgs($depsCmakeVars)) "$buildDir/third-party/" ; exitIfFailed
-  }
+if ($bits -eq 32) {
+  cmake -G $cmakeGenerator -A Win32 $(convertToCmakeArgs($depsCmakeVars)) "$buildDir/third-party/" ; exitIfFailed
 } else {
-  cmake -G $cmakeGenerator $(convertToCmakeArgs($depsCmakeVars)) "$buildDir/third-party/" ; exitIfFailed
+  cmake -G $cmakeGenerator -A x64 $(convertToCmakeArgs($depsCmakeVars)) "$buildDir/third-party/" ; exitIfFailed
 }
 cmake --build . --config $cmakeBuildType -- $cmakeGeneratorArgs ; exitIfFailed
 cd $buildDir
@@ -126,14 +81,10 @@ cd $buildDir
 # Build Neovim
 mkdir build
 cd build
-if ($compiler -eq 'MSVC') {
-  if ($bits -eq 32) {
-    cmake -G $cmakeGenerator -A Win32 $(convertToCmakeArgs($nvimCmakeVars)) .. ; exitIfFailed
-  } else {
-    cmake -G $cmakeGenerator -A x64 $(convertToCmakeArgs($nvimCmakeVars)) .. ; exitIfFailed
-  }
+if ($bits -eq 32) {
+  cmake -G $cmakeGenerator -A Win32 $(convertToCmakeArgs($nvimCmakeVars)) .. ; exitIfFailed
 } else {
-  cmake -G $cmakeGenerator $(convertToCmakeArgs($nvimCmakeVars)) .. ; exitIfFailed
+  cmake -G $cmakeGenerator -A x64 $(convertToCmakeArgs($nvimCmakeVars)) .. ; exitIfFailed
 }
 cmake --build . --config $cmakeBuildType -- $cmakeGeneratorArgs ; exitIfFailed
 .\bin\nvim --version ; exitIfFailed
diff --git a/cmake/FindLuaJit.cmake b/cmake/FindLuaJit.cmake
index 72795afefd..c904347f6a 100644
--- a/cmake/FindLuaJit.cmake
+++ b/cmake/FindLuaJit.cmake
@@ -17,8 +17,6 @@ find_path(LUAJIT_INCLUDE_DIR luajit.h
 
 if(MSVC)
   list(APPEND LUAJIT_NAMES lua51)
-elseif(MINGW)
-  list(APPEND LUAJIT_NAMES libluajit libluajit-5.1)
 else()
   list(APPEND LUAJIT_NAMES luajit-5.1)
 endif()
diff --git a/third-party/CMakeLists.txt b/third-party/CMakeLists.txt
index 21d1f7906a..36965a2e98 100644
--- a/third-party/CMakeLists.txt
+++ b/third-party/CMakeLists.txt
@@ -93,15 +93,6 @@ if(CMAKE_GENERATOR MATCHES "Makefiles")
   set(MAKE_PRG "$(MAKE)")
 endif()
 
-if(MINGW AND CMAKE_GENERATOR MATCHES "Ninja")
-  find_program(MAKE_PRG NAMES mingw32-make)
-  if(NOT MAKE_PRG)
-    message(FATAL_ERROR "GNU Make for mingw32 is required to build the dependencies.")
-  else()
-    message(STATUS "Found GNU Make for mingw32: ${MAKE_PRG}")
-  endif()
-endif()
-
 if(CMAKE_C_COMPILER_ARG1)
   set(DEPS_C_COMPILER "${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1}")
 else()
diff --git a/third-party/cmake/BuildLibuv.cmake b/third-party/cmake/BuildLibuv.cmake
index 42650308a8..9d0707201f 100644
--- a/third-party/cmake/BuildLibuv.cmake
+++ b/third-party/cmake/BuildLibuv.cmake
@@ -45,24 +45,11 @@ if(UNIX)
     CONFIGURE_COMMAND ${UNIX_CFGCMD} MAKE=${MAKE_PRG}
     INSTALL_COMMAND ${MAKE_PRG} V=1 install)
 
-elseif(MINGW AND CMAKE_CROSSCOMPILING)
-  # Build libuv for the host
-  BuildLibuv(TARGET libuv_host
-    CONFIGURE_COMMAND sh ${DEPS_BUILD_DIR}/src/libuv_host/autogen.sh && ${DEPS_BUILD_DIR}/src/libuv_host/configure --with-pic --disable-shared --prefix=${HOSTDEPS_INSTALL_DIR} CC=${HOST_C_COMPILER}
-    INSTALL_COMMAND ${MAKE_PRG} V=1 install)
-
-  # Build libuv for the target
-  BuildLibuv(
-    CONFIGURE_COMMAND ${UNIX_CFGCMD} --host=${CROSS_TARGET}
-    INSTALL_COMMAND ${MAKE_PRG} V=1 install)
-
 elseif(WIN32)
 
   set(UV_OUTPUT_DIR ${DEPS_BUILD_DIR}/src/libuv/${CMAKE_BUILD_TYPE})
   if(MSVC)
     set(BUILD_SHARED ON)
-  elseif(MINGW)
-    set(BUILD_SHARED OFF)
   else()
     message(FATAL_ERROR "Trying to build libuv in an unsupported system ${CMAKE_SYSTEM_NAME}/${CMAKE_C_COMPILER_ID}")
   endif()
diff --git a/third-party/cmake/BuildLua.cmake b/third-party/cmake/BuildLua.cmake
index a40cb7dcb2..02f762234b 100644
--- a/third-party/cmake/BuildLua.cmake
+++ b/third-party/cmake/BuildLua.cmake
@@ -39,8 +39,6 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
   set(LUA_TARGET freebsd)
 elseif(CMAKE_SYSTEM_NAME MATCHES "BSD")
   set(CMAKE_LUA_TARGET bsd)
-elseif(CMAKE_SYSTEM_NAME MATCHES "^MINGW")
-  set(CMAKE_LUA_TARGET mingw)
 else()
   if(UNIX)
     set(LUA_TARGET posix)
diff --git a/third-party/cmake/BuildLuajit.cmake b/third-party/cmake/BuildLuajit.cmake
index e02d7fe609..9c0a6cfba2 100644
--- a/third-party/cmake/BuildLuajit.cmake
+++ b/third-party/cmake/BuildLuajit.cmake
@@ -76,57 +76,6 @@ if(UNIX)
     CC=${DEPS_C_COMPILER} PREFIX=${DEPS_INSTALL_DIR}
     ${DEPLOYMENT_TARGET})
 
-elseif(MINGW AND CMAKE_CROSSCOMPILING)
-
-  # Build luajit for the host
-  BuildLuaJit(TARGET luajit_host
-    CONFIGURE_COMMAND ""
-    BUILD_COMMAND ""
-    INSTALL_COMMAND ${INSTALLCMD_UNIX}
-      CC=${HOST_C_COMPILER} PREFIX=${HOSTDEPS_INSTALL_DIR})
-
-  # Build luajit for the target
-  BuildLuaJit(
-    # Similar to Unix + cross - fPIC
-    INSTALL_COMMAND
-      ${MAKE_PRG} PREFIX=${DEPS_INSTALL_DIR}
-        BUILDMODE=static install
-        TARGET_SYS=${CMAKE_SYSTEM_NAME}
-        CROSS=${CROSS_TARGET}-
-        HOST_CC=${HOST_C_COMPILER} HOST_CFLAGS=${HOST_C_FLAGS}
-        HOST_LDFLAGS=${HOST_EXE_LINKER_FLAGS}
-        FILE_T=luajit.exe
-        Q=
-        INSTALL_TSYMNAME=luajit.exe)
-
-elseif(MINGW)
-
-  if(CMAKE_GENERATOR MATCHES "Ninja")
-    set(LUAJIT_MAKE_PRG ${MAKE_PRG})
-  else()
-    set(LUAJIT_MAKE_PRG ${CMAKE_MAKE_PROGRAM})
-  endif()
-  BuildLuaJit(BUILD_COMMAND ${LUAJIT_MAKE_PRG} CC=${DEPS_C_COMPILER}
-                                PREFIX=${DEPS_INSTALL_DIR}
-                                CFLAGS+=-DLUA_USE_APICHECK
-                                CFLAGS+=-funwind-tables
-                                CCDEBUG+=-g
-                                BUILDMODE=static
-                      # Build a DLL too
-                      COMMAND ${LUAJIT_MAKE_PRG} CC=${DEPS_C_COMPILER} BUILDMODE=dynamic
-
-          INSTALL_COMMAND ${CMAKE_COMMAND} -E make_directory ${DEPS_INSTALL_DIR}/bin
-	    COMMAND ${CMAKE_COMMAND} -E copy ${DEPS_BUILD_DIR}/src/luajit/src/luajit.exe ${DEPS_INSTALL_DIR}/bin
-	    COMMAND ${CMAKE_COMMAND} -E copy ${DEPS_BUILD_DIR}/src/luajit/src/lua51.dll ${DEPS_INSTALL_DIR}/bin
-	    COMMAND ${CMAKE_COMMAND} -E make_directory ${DEPS_INSTALL_DIR}/lib
-	    # Luarocks searches for lua51.dll in lib
-	    COMMAND ${CMAKE_COMMAND} -E copy ${DEPS_BUILD_DIR}/src/luajit/src/lua51.dll ${DEPS_INSTALL_DIR}/lib
-	    COMMAND ${CMAKE_COMMAND} -E copy ${DEPS_BUILD_DIR}/src/luajit/src/libluajit.a ${DEPS_INSTALL_DIR}/lib
-	    COMMAND ${CMAKE_COMMAND} -E make_directory ${DEPS_INSTALL_DIR}/include/luajit-2.1
-	    COMMAND ${CMAKE_COMMAND} -DFROM_GLOB=${DEPS_BUILD_DIR}/src/luajit/src/*.h -DTO=${DEPS_INSTALL_DIR}/include/luajit-2.1 -P ${CMAKE_CURRENT_SOURCE_DIR}/cmake/CopyFilesGlob.cmake
-	    COMMAND ${CMAKE_COMMAND} -E make_directory ${DEPS_INSTALL_DIR}/bin/lua/jit
-	    COMMAND ${CMAKE_COMMAND} -E copy_directory ${DEPS_BUILD_DIR}/src/luajit/src/jit ${DEPS_INSTALL_DIR}/bin/lua/jit
-	    )
 elseif(MSVC)
 
   BuildLuaJit(
diff --git a/third-party/cmake/BuildLuarocks.cmake b/third-party/cmake/BuildLuarocks.cmake
index 244d1d9fb8..98783d533e 100644
--- a/third-party/cmake/BuildLuarocks.cmake
+++ b/third-party/cmake/BuildLuarocks.cmake
@@ -56,7 +56,7 @@ endif()
 # Defaults to 5.1 for bundled LuaJIT/Lua.
 set(LUA_VERSION "5.1")
 
-if(UNIX OR (MINGW AND CMAKE_CROSSCOMPILING))
+if(UNIX)
 
   if(USE_BUNDLED_LUAJIT)
     list(APPEND LUAROCKS_OPTS
@@ -94,13 +94,9 @@ if(UNIX OR (MINGW AND CMAKE_CROSSCOMPILING))
     CONFIGURE_COMMAND ${DEPS_BUILD_DIR}/src/luarocks/configure
       --prefix=${HOSTDEPS_INSTALL_DIR} --force-config ${LUAROCKS_OPTS}
     INSTALL_COMMAND ${MAKE_PRG} -j1 bootstrap)
-elseif(MSVC OR MINGW)
+elseif(MSVC)
 
-  if(MINGW)
-    set(COMPILER_FLAG /MW)
-  elseif(MSVC)
-    set(COMPILER_FLAG /MSVC)
-  endif()
+  set(COMPILER_FLAG /MSVC)
 
   # Ignore USE_BUNDLED_LUAJIT - always ON for native Win32
   BuildLuarocks(INSTALL_COMMAND install.bat /FORCECONFIG /NOREG /NOADMIN /Q /F
@@ -123,9 +119,6 @@ list(APPEND THIRD_PARTY_DEPS luarocks)
 
 if(USE_BUNDLED_LUAJIT)
   add_dependencies(luarocks luajit)
-  if(MINGW AND CMAKE_CROSSCOMPILING)
-    add_dependencies(luarocks luajit_host)
-  endif()
 elseif(USE_BUNDLED_LUA)
   add_dependencies(luarocks lua)
 endif()
@@ -196,9 +189,6 @@ if(USE_BUNDLED_BUSTED)
   set(LUV_DEPS luacheck)
   if(USE_BUNDLED_LUV)
     list(APPEND LUV_DEPS luv-static lua-compat-5.3)
-    if(MINGW AND CMAKE_CROSSCOMPILING)
-      list(APPEND LUV_DEPS libuv_host)
-    endif()
     set(LUV_ARGS "CFLAGS=-O0 -g3 -fPIC")
     if(USE_BUNDLED_LIBUV)
       list(APPEND LUV_ARGS LIBUV_DIR=${HOSTDEPS_INSTALL_DIR})
diff --git a/third-party/cmake/BuildLuv.cmake b/third-party/cmake/BuildLuv.cmake
index 99822249c2..001f5a325a 100644
--- a/third-party/cmake/BuildLuv.cmake
+++ b/third-party/cmake/BuildLuv.cmake
@@ -91,16 +91,7 @@ if(USE_BUNDLED_LIBUV)
     -DCMAKE_PREFIX_PATH=${DEPS_INSTALL_DIR})
 endif()
 
-if(MINGW AND CMAKE_CROSSCOMPILING)
-  get_filename_component(TOOLCHAIN ${CMAKE_TOOLCHAIN_FILE} REALPATH)
-  set(LUV_CONFIGURE_COMMAND
-    ${LUV_CONFIGURE_COMMAND_COMMON}
-    # Pass toolchain
-    -DCMAKE_TOOLCHAIN_FILE=${TOOLCHAIN}
-    "-DCMAKE_C_FLAGS:STRING=${LUV_INCLUDE_FLAGS} -D_WIN32_WINNT=0x0600"
-    # Hack to avoid -rdynamic in Mingw
-    -DCMAKE_SHARED_LIBRARY_LINK_C_FLAGS="")
-elseif(MSVC)
+if(MSVC)
   set(LUV_CONFIGURE_COMMAND
     ${LUV_CONFIGURE_COMMAND_COMMON}
     -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
diff --git a/third-party/cmake/BuildMsgpack.cmake b/third-party/cmake/BuildMsgpack.cmake
index f66a3bdd32..a89c1e34d0 100644
--- a/third-party/cmake/BuildMsgpack.cmake
+++ b/third-party/cmake/BuildMsgpack.cmake
@@ -42,18 +42,7 @@ set(MSGPACK_CONFIGURE_COMMAND ${CMAKE_COMMAND} ${DEPS_BUILD_DIR}/src/msgpack
 set(MSGPACK_BUILD_COMMAND ${CMAKE_COMMAND} --build . --config ${CMAKE_BUILD_TYPE})
 set(MSGPACK_INSTALL_COMMAND ${CMAKE_COMMAND} --build . --target install --config ${CMAKE_BUILD_TYPE})
 
-if(MINGW AND CMAKE_CROSSCOMPILING)
-  get_filename_component(TOOLCHAIN ${CMAKE_TOOLCHAIN_FILE} REALPATH)
-  set(MSGPACK_CONFIGURE_COMMAND ${CMAKE_COMMAND} ${DEPS_BUILD_DIR}/src/msgpack
-    -DMSGPACK_BUILD_TESTS=OFF
-    -DMSGPACK_BUILD_EXAMPLES=OFF
-    -DCMAKE_INSTALL_PREFIX=${DEPS_INSTALL_DIR}
-    # Pass toolchain
-    -DCMAKE_TOOLCHAIN_FILE=${TOOLCHAIN}
-    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
-    # Hack to avoid -rdynamic in Mingw
-    -DCMAKE_SHARED_LIBRARY_LINK_C_FLAGS="")
-elseif(MSVC)
+if(MSVC)
   # Same as Unix without fPIC
   set(MSGPACK_CONFIGURE_COMMAND ${CMAKE_COMMAND} ${DEPS_BUILD_DIR}/src/msgpack
     -DMSGPACK_BUILD_TESTS=OFF