Add workflow to build packages for iOS.

Add workflow to build packages for iOS on a macOS VM. Can't run tests at this
time, but we can at least confirm source compiles.

Author: grynspan

.github/workflows/pull_request.yml

@@ -77,6 +77,19 @@ jobs:
         xcrun swift package init --type library
         xcrun swift build
 
+  tests_ios:
+    name: Test iOS
+    uses: ./.github/workflows/swift_package_test.yml
+    with:
+      enable_linux_checks: false
+      enable_windows_checks: false
+      # iOS
+      enable_ios_checks: true
+      ios_pre_build_command: |
+        mkdir MyPackage
+        cd MyPackage
+        xcrun swift package init --type library
+
   soundness:
     name: Soundness
     uses: ./.github/workflows/soundness.yml

.github/workflows/swift_package_test.yml

@@ -19,6 +19,22 @@ on:
         type: string
         description: "macOS arch list (JSON)"
         default: "[\"ARM64\"]"
+      ios_host_xcode_versions:
+        type: string
+        description: "Xcode version list (JSON)"
+        default: null
+      ios_host_exclude_xcode_versions:
+        type: string
+        description: "Exclude Xcode version list (JSON)"
+        default: null
+      ios_host_versions:
+        type: string
+        description: "iOS host (macOS) version list (JSON)"
+        default: null
+      ios_host_archs:
+        type: string
+        description: "iOS host (macOS) arch list (JSON)"
+        default: null
       linux_swift_versions:
         type: string
         description: "Include Linux Swift version list (JSON)"
@@ -84,6 +100,14 @@ on:
         type: string
         description: "macOS command to build and test the package"
         default: "xcrun swift test"
+      ios_pre_build_command:
+        type: string
+        description: "macOS command to execute before building the Swift package for iOS"
+        default: ""
+      ios_build_command:
+        type: string
+        description: "macOS command to build the package for iOS"
+        default: "xcrun swift build --build-tests --sdk \"$(xcrun --sdk iphoneos --show-sdk-path)\" --triple arm64-apple-ios"
       linux_build_command:
         type: string
         description: "Linux command to build and test the package"
@@ -110,6 +134,9 @@ on:
       macos_env_vars:
         description: "Newline separated list of environment variables"
         type: string
+      ios_host_env_vars:
+        description: "Newline separated list of environment variables"
+        type: string
       linux_env_vars:
         description: "Newline separated list of environment variables"
         type: string
@@ -136,6 +163,10 @@ on:
         type: boolean
         description: "Boolean to enable macOS testing. Defaults to false"
         default: false
+      enable_ios_checks:
+        type: boolean
+        description: "Boolean to enable iOS testing. Defaults to false"
+        default: false
       enable_windows_checks:
         type: boolean
         description: "Boolean to enable windows testing. Defaults to true"
@@ -192,6 +223,42 @@ jobs:
         run: ${{ inputs.macos_build_command }} ${{ (contains(matrix.swift_version, 'nightly') && inputs.swift_nightly_flags) || inputs.swift_flags }}
         timeout-minutes: 60
 
+  ios-build:
+    name: iOS (Build Only, Xcode ${{ matrix.xcode_version }} - ${{ matrix.os_version }} - ${{ matrix.arch }})
+    if: ${{ inputs.enable_ios_checks }}
+    runs-on: [self-hosted, macos, "${{ matrix.os_version }}", "${{ matrix.arch }}"]
+    strategy:
+      fail-fast: false
+      matrix:
+        xcode_version: ${{ fromJson(inputs.ios_host_xcode_versions || inputs.macos_xcode_versions) }}
+        os_version: ${{ fromJson(inputs.ios_host_versions || inputs.macos_versions) }}
+        arch: ${{ fromJson(inputs.ios_host_archs || inputs.macos_archs) }}
+        exclude:
+          - ${{ fromJson(inputs.ios_host_exclude_xcode_versions || inputs.macos_exclude_xcode_versions) }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Provide token
+        if: ${{ inputs.needs_token }}
+        run: |
+            echo "GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }}" >> $GITHUB_ENV
+      - name: Set environment variables
+        if: ${{ inputs.ios_host_env_vars }}
+        run: |
+            for i in "${{ inputs.ios_host_env_vars }}"
+            do
+              printf "%s\n" $i >> $GITHUB_ENV
+            done
+      - name: Select Xcode
+        run: echo "DEVELOPER_DIR=/Applications/Xcode_${{ matrix.xcode_version }}.app" >> $GITHUB_ENV
+      - name: Swift version
+        run: xcrun swift --version
+      - name: Pre-build
+        run: ${{ inputs.ios_pre_build_command }}
+      - name: Build
+        run: ${{ inputs.ios_build_command }} ${{ (contains(matrix.swift_version, 'nightly') && inputs.swift_nightly_flags) || inputs.swift_flags }}
+        timeout-minutes: 60
+
   linux-build:
     name: Linux (${{ matrix.swift_version }} - ${{ matrix.os_version }})
     if: ${{ inputs.enable_linux_checks }}