add an option to get rid of symlinks in /bin

2 files changed, 86 insertions, 9 deletions

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4cb74e7..5866f16 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,19 +13,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-2019]
         platform: [x86, x64]
         env: ['', 'winsymlinks:nativestrict']
+        hardlinks: [0, 1]
 
         include:
-          - {os: windows-2019, name: 'Windows 2019'}
+          - {env: '', env_descr: 'nativestrict: 0'}
+          - {env: 'winsymlinks:nativestrict', env_descr: 'nativestrict: 1'}
 
-          - {env: '', env_descr: 'Empty %CYGWIN%'}
-          - {env: 'winsymlinks:nativestrict', env_descr: 'Custom %CYGWIN%'}
+          - {hardlinks: 0, hardlinks_descr: 'Hardlinks: 0'}
+          - {hardlinks: 1, hardlinks_descr: 'Hardlinks: 1'}
 
-    runs-on: '${{ matrix.os }}'
+    runs-on: windows-2019
 
-    name: '${{ matrix.name }} / ${{ matrix.platform }} / ${{ matrix.env_descr }}'
+    name: '${{ matrix.platform }} / ${{ matrix.env_descr }} / ${{ matrix.hardlinks_descr }}'
 
     defaults:
       run:
@@ -35,25 +36,43 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
 
+      - name: Clean up PATH
+        uses: egor-tensin/cleanup-path@v1
+        if: runner.os == 'Windows'
+
       - name: Set up Cygwin
         id: setup
         uses: ./
         with:
           platform: '${{ matrix.platform }}'
           install-dir: C:\cg
-          packages: cmake gcc
+          packages: cmake gcc python3
           env: '${{ matrix.env }}'
+          symlinks-to-hardlinks: '${{ matrix.hardlinks }}'
 
       - name: Run bash
         run: |
-          $output = C:\cg\bin\bash.exe --login -c 'echo foobar'
+          $((Get-Command bash.exe).Path -eq 'C:\cg\bin\bash.exe') -or $(throw (Get-Command bash.exe))
+          $output = bash.exe --login -c 'echo foobar'
           $($output -eq 'foobar') -or $(throw $output)
 
       - name: Run cmake
         run: |
-          C:\cg\bin\cmake.exe --version
+          $((Get-Command cmake.exe).Path -eq 'C:\cg\bin\cmake.exe') -or $(throw (Get-Command cmake.exe))
+          cmake.exe --version
 
       - name: Check CYGWIN environment variable
         run: |
           $(Test-Path env:CYGWIN) -or $(throw '%CYGWIN% is not set!')
           $($env:CYGWIN -eq '${{ matrix.env }}') -or $(throw "Unexpected %CYGWIN% value: $env:CYGWIN")
+
+      - name: python3 is a symlink
+        run: |
+          $(Get-Command python3.exe -ErrorAction SilentlyContinue) -and $(throw (Get-Command python3.exe))
+        if: '!matrix.hardlinks'
+
+      - name: python3 is a hardlink
+        run: |
+          $((Get-Command python3.exe).Path -eq 'C:\cg\bin\python3.exe') -or $(throw (Get-Command python3.exe))
+          python3.exe --version
+        if: matrix.hardlinks
diff --git a/action.yml b/action.yml
index 9de9583..62d021a 100644
--- a/action.yml
+++ b/action.yml
@@ -16,6 +16,10 @@ inputs:
   env:
     description: Value to set as the CYGWIN environment variable
     required: false
+  symlinks-to-hardlinks:
+    description: Convert symlinks in /usr/bin to hardlinks
+    required: false
+    default: 0
 
 runs:
   using: composite
@@ -28,6 +32,14 @@ runs:
         New-Variable x64 -Value ('${{ inputs.platform }}' -eq 'x64') -Option Constant
         New-Variable install_dir -Value '${{ inputs.install-dir }}' -Option Constant
         New-Variable packages -Value '${{ inputs.packages }}' -Option Constant
+        New-Variable symlinks_to_hardlinks -Value ('${{ inputs.symlinks-to-hardlinks }}' -eq '1') -Option Constant
+
+        New-Variable bin_dir -Value (Join-Path $install_dir bin) -Option Constant
+        New-Variable realpath -Value (Join-Path $bin_dir realpath.exe) -Option Constant
+        New-Variable readlink -Value (Join-Path $bin_dir readlink.exe) -Option Constant
+        New-Variable dirname -Value (Join-Path $bin_dir dirname.exe) -Option Constant
+        New-Variable cygpath -Value (Join-Path $bin_dir cygpath.exe) -Option Constant
+        New-Variable find -Value (Join-Path $bin_dir find.exe) -Option Constant
 
         function Locate-Choco {
             $path = Get-Command 'choco' -ErrorAction SilentlyContinue
@@ -38,6 +50,48 @@ runs:
             }
         }
 
+        function Convert-CygwinPath {
+            # Like cygpath -wa, but don't resolve symlinks.
+            param(
+                [Parameter(Mandatory=$true)]
+                [string] $Path
+            )
+
+            $realpath = & $script:realpath --no-symlinks -- $Path
+            $dirname = & $script:dirname -- $realpath
+            $dirname = & $script:cygpath -wa $dirname
+            Join-Path $dirname (Split-Path $realpath -Leaf)
+        }
+
+        function Fix-CygwinLink {
+            # Replace a Cygwin symlink with a hardlink.
+            param(
+                [Parameter(Mandatory=$true)]
+                [string] $Path
+            )
+
+            $link_path = $Path
+            $link_winpath = Convert-CygwinPath $link_path
+            $link_ext = [System.IO.Path]::GetExtension($link_path)
+
+            $dest_path = & $script:readlink --canonicalize-existing -- $link_path
+            $dest_winpath = Convert-CygwinPath $dest_path
+            $dest_ext = [System.IO.Path]::GetExtension($dest_path)
+
+            echo "Removing symlink: $link_winpath"
+            Remove-Item $link_winpath -Force
+
+            # If target is an executable (i.e. its name contains one of the
+            # PATHEXT extensions), make sure the hardlink has the same
+            # extension.
+            $exe_exts = $env:PATHEXT.ToLower().Split(';', [System.StringSplitOptions]::RemoveEmptyEntries)
+            if ($exe_exts -contains $dest_ext.ToLower() -and $dest_ext.ToLower() -ne $link_ext.ToLower()) {
+                $link_winpath += $dest_ext
+            }
+            echo "Creating hardlink '$link_winpath', pointing to '$dest_winpath'"
+            New-Item -ItemType HardLink -Path $link_winpath -Value $dest_winpath | Out-Null
+        }
+
         if ($windows_host) {
             echo 'CYGWIN=${{ inputs.env }}' >> $env:GITHUB_ENV
 
@@ -66,6 +120,10 @@ runs:
             if ($pkg_list.Count -gt 0) {
                 & $choco install -y --no-progress --source=cygwin $pkg_list
             }
+
+            if ($symlinks_to_hardlinks) {
+                & $find /usr/bin -type l | %{ Fix-CygwinLink $_ }
+            }
         } else {
             throw "Sorry, installing Cygwin is unsupported on $os"
         }