[CI] add test to check libFoundation.so & co are not linked to the binary

Author: sebsto

.github/workflows/integration_tests.yml

@@ -23,6 +23,10 @@ on:
         type: boolean
         description: "Boolean to enable the test of the archive plugin. Defaults to true."
         default: true
+      check_foundation_enabled:
+        type: boolean
+        description: "Boolean to enable the check for Foundation dependency. Defaults to true."
+        default: true
       matrix_linux_command:
         type: string
         description: "The command of the current Swift version linux matrix job to execute."
@@ -95,8 +99,6 @@ jobs:
     name: Test archive plugin
     if: ${{ inputs.archive_plugin_enabled }}
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -128,3 +130,45 @@ jobs:
 
           echo "✅ The archive plugin is OK"
           popd
+
+  check-foundation:
+    name: Check if there is a dependency on Foundation
+    if: ${{ inputs.check_foundation_enabled }}
+    runs-on: ubuntu-latest
+    # depends on test-archive-plugin to speedup the check (no need to rebuild the project)
+    needs: test-archive-plugin
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Mark the workspace as safe
+        # https://github.com/actions/checkout/issues/766
+        run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+      - name: Check for Foundation or ICU dependency
+        env:
+          # we check the API Gateway example as it has a dependency on Swift AWS Lambda Events
+          # this allows to test the two libraries at onece
+          # TODO : add a similar test to Swift AWS Lambda Events
+          EXAMPLE: APIGateway 
+          OUTPUT_DIR: .build/release
+          OUTPUT_FILE: ${OUTPUT_DIR}/APIGatewayLambda
+          LIBS_TO_CHECK: "libFoundation.so libFoundationInternationalization.so lib_FoundationICU.so"
+        run: |
+          pushd Examples/${EXAMPLE}
+
+          # recompile the example without the --static-swift-stdlib flag
+          LAMBDA_USE_LOCAL_DEPS=../.. swift build -c release -Xlinker -s
+
+          for LIB in ${LIBS_TO_CHECK}; do
+            # check if the binary has a dependency on Foundation or ICU
+            ldd ${OUTPUT_FILE} | grep ${LIB} # return 1 if not found
+            # 1 is success (grep failed to find the lib), 0 is failure (grep successly found the lib)
+            SUCCESS=$?
+            [ $SUCCESS -eq 0 ] && echo "${LIB} found" && break
+          done
+
+          popd
+
+          # exit code is the opposite of the grep exit code
+          [ $SUCCESS -eq 0 ] && exit 1 || exit 0