Add Cygwin GitHub Action.

.github/workflows/autotools.yml

@@ -71,8 +71,13 @@ jobs:
       with:
             build_mode: "production"
 
+    call-release-auto-cygwin:
+      name: "Autotools Cygwin Workflows"
+      uses: ./.github/workflows/cygwin-auto.yml
+
     call-release-auto-aocc:
       name: "Autotools aocc Workflows"
       uses: ./.github/workflows/aocc-ompi-auto.yml
+
       with:
             build_mode: "production"

.github/workflows/cmake.yml

@@ -74,8 +74,13 @@ jobs:
         with:
             build_mode: "Release"
 
+    call-release-cmake-cygwin:
+        name: "CMake Cygwin Workflows"
+        uses: ./.github/workflows/cygwin-cmake.yml
+
     call-release-cmake-aocc:
         name: "CMake nvhpc Workflows"
         uses: ./.github/workflows/aocc-ompi-cmake.yml
+
         with:
             build_mode: "Release"

.github/workflows/cygwin-auto.yml

@@ -0,0 +1,59 @@
+name: hdf5 dev autotools Cygwin
+
+on:
+  workflow_call:
+    inputs:
+      build_mode:
+        description: "release vs. debug build"
+        required: true
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  cygwin_build_and_test:
+    name: "Cygwin ${{ inputs.build_mode }}"
+    runs-on: windows-latest
+    steps:
+      - name: Set git to use LF
+        run: |
+          git config --global core.autocrlf input
+
+      - uses: actions/checkout@v4
+
+      - name: Install Cygwin
+        uses: cygwin/cygwin-install-action@master
+        with:
+          packages: automake make gcc-fortran libjpeg-devel libtool zlib-devel
+
+      - name: Autotools Configure
+        run: |
+          export PATH=/usr/bin:$PATH
+          ./autogen.sh
+          ./configure --enable-build-mode=${{ inputs.build_mode }}
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Autotools Build
+        run: |
+          export PATH=/usr/bin:$PATH
+          make
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Autotools Run Tests
+        run: |
+          export PATH=/usr/bin:$PATH
+          make check
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Autotools Install
+        run: |
+          export PATH=/usr/bin:$PATH
+          make install
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Autotools Uninstall
+        run: |
+          export PATH=/usr/bin:$PATH
+          make uninstall
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'

.github/workflows/cygwin-cmake.yml

@@ -0,0 +1,50 @@
+name: hdf5 dev CMake Cygwin
+
+on:
+  workflow_call:
+    inputs:
+      build_mode:
+        description: "release vs. debug build"
+        required: true
+        type: string
+
+jobs:
+  cygwin_build_and_test:
+    name: "Cygwin ${{ inputs.build_mode }}"
+    runs-on: windows-latest
+    steps:
+      - name: Set git to use LF
+        run: |
+          git config --global core.autocrlf input
+
+      - uses: actions/checkout@v4
+
+      - name: Install Cygwin
+        uses: cygwin/cygwin-install-action@master
+        with:
+          packages: cmake gcc-fortran make ninja perl zlib-devel
+
+      - name: Configure
+        run: |
+          export PATH=/usr/bin:$PATH
+          mkdir build
+          cd build
+          cmake -G Ninja \
+          -DCMAKE_BUILD_TYPE=${{ inputs.build_mode }} \
+          -D BUILD_SHARED_LIBS:BOOL=OFF \
+           ..
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Build
+        run: |
+          export PATH=/usr/bin:$PATH
+          cd build
+          ctest -T Build
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'
+
+      - name: Test
+        run: |
+          export PATH=/usr/bin:$PATH
+          cd build
+          ctest -T Test
+        shell: C:\cygwin\bin\bash.exe -eo pipefail -o igncr '{0}'

config/cmake/ConfigureChecks.cmake

@@ -51,6 +51,10 @@ endmacro ()
 # ----------------------------------------------------------------------
 set (WINDOWS)
 
+if (CYGWIN)
+    set (HDF5_CMAKE_C_FLAGS ${HDF5_CMAKE_C_FLAGS} -D_GNU_SOURCE)
+endif()
+
 if (MINGW)
   set (${HDF_PREFIX}_HAVE_MINGW 1)
   set (WINDOWS 1) # MinGW tries to imitate Windows

configure.ac

@@ -1519,6 +1519,10 @@ case "$host_cpu-$host_vendor-$host_os" in
     AC_DEFINE([HAVE_MINGW], [1], [Define if using MinGW])
     H5_CPPFLAGS="-D_GNU_SOURCE -D__USE_MINGW_ANSI_STDIO $H5_CPPFLAGS"
     ;;
+  *cygwin*)
+    AC_DEFINE([HAVE_CYGWIN], [1], [Define if using Cygwin])
+    H5_CPPFLAGS="-D_GNU_SOURCE $H5_CPPFLAGS"
+    ;;
 esac
 
 ## Need to add the AM_ and H5_ into CFLAGS/CPPFLAGS to make them visible