Update LinkageTest to check all modules we provide

.github/workflows/pull_request.yml

@@ -342,6 +342,11 @@ jobs:
       image: swift:6.3-noble
     steps:
       - uses: actions/checkout@v7
+      - name: Install jq
+        shell: bash
+        run: |
+          apt-get update -qq
+          apt-get install -qq -y jq
       - name: Prepare CI Environment
         uses: ./.github/actions/prepare_env
       - name: Cache Tests/LinkageTest/.build

Tests/LinkageTest/Package.swift

@@ -3,6 +3,26 @@
 import Foundation
 import PackageDescription
 
+// Every runtime product exported from swift-java should be included here.
+// This is to verify none of the modules would accidentally pull in Foundation.
+// `scripts/run-linkage-test.sh` enforces set equality with the root package.
+let runtimeLibraryProducts: [String] = [
+  // RUNTIME_LIBRARY_PRODUCTS:START
+  "JavaIO",
+  "JavaLangReflect",
+  "JavaNet",
+  "JavaUtil",
+  "JavaUtilFunction",
+  "JavaUtilJar",
+  "SwiftJava",
+  "SwiftRuntimeFunctions",
+  // RUNTIME_LIBRARY_PRODUCTS:END
+]
+
+let runtimeDependencies: [Target.Dependency] = runtimeLibraryProducts.map {
+  .product(name: $0, package: "swift-java")
+}
+
 let package = Package(
   name: "linkage-test",
   platforms: [
@@ -14,15 +34,11 @@ let package = Package(
   targets: [
     .executableTarget(
       name: "LinkageTest",
-      dependencies: [
-        .product(name: "SwiftJava", package: "swift-java")
-      ]
+      dependencies: runtimeDependencies
     ),
     .executableTarget(
       name: "JExtractLinkageTest",
-      dependencies: [
-        .product(name: "SwiftJava", package: "swift-java")
-      ],
+      dependencies: runtimeDependencies,
       exclude: [
         "swift-java.config"
       ],

Tests/LinkageTest/Sources/JExtractLinkageTest/main.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2024-2025 Apple Inc. and the Swift.org project authors
+// Copyright (c) 2024-2026 Apple Inc. and the Swift.org project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -12,7 +12,18 @@
 //
 //===----------------------------------------------------------------------===//
 
+// See `Package.swift` for the authoritative list.
+// IMPORT_RUNTIME_LIBRARY_PRODUCTS:START
+import JavaIO
+import JavaLangReflect
+import JavaNet
+import JavaUtil
+import JavaUtilFunction
+import JavaUtilJar
 import SwiftJava
+import SwiftRuntimeFunctions
+
+// IMPORT_RUNTIME_LIBRARY_PRODUCTS:END
 
 let _ = try? JavaVirtualMachine.shared()
 let _ = SwiftPlatform.debugOrRelease

Tests/LinkageTest/Sources/LinkageTest/main.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2024-2025 Apple Inc. and the Swift.org project authors
+// Copyright (c) 2024-2026 Apple Inc. and the Swift.org project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -12,7 +12,21 @@
 //
 //===----------------------------------------------------------------------===//
 
+// Import every runtime library product exported from swift-java. If any of
+// these libraries accidentally does `import Foundation` we'll catch it via `ldd`.
+//
+// See `Package.swift` for the authoritative list.
+// IMPORT_RUNTIME_LIBRARY_PRODUCTS:START
+import JavaIO
+import JavaLangReflect
+import JavaNet
+import JavaUtil
+import JavaUtilFunction
+import JavaUtilJar
 import SwiftJava
+import SwiftRuntimeFunctions
+
+// IMPORT_RUNTIME_LIBRARY_PRODUCTS:END
 
 let _ = try? JavaVirtualMachine.shared()
 let _ = SwiftPlatform.debugOrRelease

scripts/run-linkage-test.sh

@@ -14,13 +14,185 @@
 ##===----------------------------------------------------------------------===##
 set -eu
 
-# Validate that we're running on Linux
-if [[ "$(uname -s)" != "Linux" ]]; then
+DRY_RUN=false
+for arg in "$@"; do
+    case "$arg" in
+        --dry-run)
+            DRY_RUN=true
+            ;;
+        -h|--help)
+            cat <<'EOF'
+Usage: run-linkage-test.sh [--dry-run]
+
+Verifies that the linkage test package and its source files cover every
+runtime library product exported from swift-java, then (on Linux) builds
+those executables and confirms none of them link libFoundation.so.
+
+  --dry-run   Only run the imports-in-sync check. 
+              Skips the Linux-only build + ldd steps.
+EOF
+            exit 0
+            ;;
+        *)
+            echo "Error: unknown argument: $arg" >&2
+            echo "Run with --help for usage." >&2
+            exit 1
+            ;;
+    esac
+done
+
+# Validate that we're running on Linux (unless we're only doing the
+# imports-in-sync check).
+if ! $DRY_RUN && [[ "$(uname -s)" != "Linux" ]]; then
     echo "Error: This script must be run on Linux. Current OS: $(uname -s)" >&2
+    echo "Hint: pass --dry-run to run the imports-in-sync check on any OS." >&2
     exit 1
 fi
 
-echo "Detected JAVA_HOME=${JAVA_HOME}"
+if ! $DRY_RUN; then
+    echo "Detected JAVA_HOME=${JAVA_HOME}"
+fi
+
+# Verify that Tests/LinkageTest/Package.swift and tests include all the runtime libraries.
+# This is because if any of them accidentally pulls Foundation, that'd be bad.
+#
+# We inspect:
+#   - any library product whose name starts with "Java"
+#   - "SwiftJava"
+#   - "SwiftRuntimeFunctions"
+# Anything else (tooling, docs, samples, `*Static` linkage variants) is
+# ignored on purpose.
+#
+# The expected list is derived from `swift package describe --type json` on
+# the root package so it stays honest as products are added or renamed.
+verify_linkage_test_covers_runtime_products() {
+    local linkage_pkg="Tests/LinkageTest/Package.swift"
+
+    if [[ ! -f "Package.swift" || ! -f "$linkage_pkg" ]]; then
+        echo "Error: cannot find Package.swift or $linkage_pkg from $(pwd)" >&2
+        exit 1
+    fi
+
+    if ! command -v jq >/dev/null 2>&1; then
+        echo "Error: 'jq' is required to parse 'swift package describe --type json'." >&2
+        echo "Install it with your package manager (e.g. 'apt-get install -y jq') and re-run." >&2
+        exit 1
+    fi
+
+    local expected
+    expected=$(
+        swift package --disable-sandbox describe --type json \
+            | jq -r '
+                .products[]
+                | select(.type.library != null)
+                | .name
+                | select(startswith("Java") or . == "SwiftJava" or . == "SwiftRuntimeFunctions")
+            ' \
+            | sort -u
+    )
+
+    if [[ -z "$expected" ]]; then
+        echo "Error: could not extract runtime library products from 'swift package describe'." >&2
+        echo "The parser in run-linkage-test.sh likely needs updating." >&2
+        exit 1
+    fi
+
+    # Actual list, between the markers in Tests/LinkageTest/Package.swift.
+    local actual
+    actual=$(
+        awk '
+            /RUNTIME_LIBRARY_PRODUCTS:START/ { collecting = 1; next }
+            /RUNTIME_LIBRARY_PRODUCTS:END/   { collecting = 0 }
+            collecting && match($0, /"[^"]+"/) {
+                name = substr($0, RSTART + 1, RLENGTH - 2)
+                print name
+            }
+        ' "$linkage_pkg" | sort -u
+    )
+
+    if [[ -z "$actual" ]]; then
+        echo "Error: no entries found between RUNTIME_LIBRARY_PRODUCTS:START/END in $linkage_pkg." >&2
+        echo "The linkage test would silently under-cover the runtime libraries." >&2
+        exit 1
+    fi
+
+    local missing extra
+    missing=$(comm -23 <(printf '%s\n' "$expected") <(printf '%s\n' "$actual"))
+    extra=$(comm -13 <(printf '%s\n' "$expected") <(printf '%s\n' "$actual"))
+
+    if [[ -n "$missing" || -n "$extra" ]]; then
+        echo "Error: $linkage_pkg RUNTIME_LIBRARY_PRODUCTS list is out of sync with the root package." >&2
+        if [[ -n "$missing" ]]; then
+            echo "  Missing from linkage test (add these):" >&2
+            printf '%s\n' "$missing" | sed 's/^/    /' >&2
+        fi
+        if [[ -n "$extra" ]]; then
+            echo "  Present in linkage test but not a runtime library product:" >&2
+            printf '%s\n' "$extra" | sed 's/^/    /' >&2
+        fi
+        echo "Update the RUNTIME_LIBRARY_PRODUCTS list and re-run." >&2
+        exit 1
+    fi
+
+    # Every linkage-test source file that imports the runtime products must also stay in sync. 
+    # Sources delimit their `import` block with `IMPORT_RUNTIME_LIBRARY_PRODUCTS:START` / `:END`.
+    local import_source
+    for import_source in \
+        Tests/LinkageTest/Sources/LinkageTest/main.swift \
+        Tests/LinkageTest/Sources/JExtractLinkageTest/main.swift
+    do
+        if [[ ! -f "$import_source" ]]; then
+            echo "Error: expected linkage-test source $import_source not found." >&2
+            exit 1
+        fi
+
+        local imported
+        imported=$(
+            awk '
+                /IMPORT_RUNTIME_LIBRARY_PRODUCTS:START/ { collecting = 1; next }
+                /IMPORT_RUNTIME_LIBRARY_PRODUCTS:END/   { collecting = 0 }
+                collecting && match($0, /^[[:space:]]*import[[:space:]]+[A-Za-z_][A-Za-z0-9_]*/) {
+                    line = substr($0, RSTART, RLENGTH)
+                    sub(/^[[:space:]]*import[[:space:]]+/, "", line)
+                    print line
+                }
+            ' "$import_source" | sort -u
+        )
+
+        if [[ -z "$imported" ]]; then
+            echo "Error: no imports found between IMPORT_RUNTIME_LIBRARY_PRODUCTS:START/END in $import_source." >&2
+            exit 1
+        fi
+
+        local src_missing src_extra
+        src_missing=$(comm -23 <(printf '%s\n' "$expected") <(printf '%s\n' "$imported"))
+        src_extra=$(comm -13 <(printf '%s\n' "$expected") <(printf '%s\n' "$imported"))
+
+        if [[ -n "$src_missing" || -n "$src_extra" ]]; then
+            echo "Error: imports in $import_source are out of sync with the root package." >&2
+            if [[ -n "$src_missing" ]]; then
+                echo "  Missing imports (add these):" >&2
+                printf '%s\n' "$src_missing" | sed 's/^/    import /' >&2
+            fi
+            if [[ -n "$src_extra" ]]; then
+                echo "  Imports not backed by a runtime library product:" >&2
+                printf '%s\n' "$src_extra" | sed 's/^/    import /' >&2
+            fi
+            echo "Update the import block between the IMPORT_RUNTIME_LIBRARY_PRODUCTS markers and re-run." >&2
+            exit 1
+        fi
+    done
+
+    echo "Linkage test covers all runtime library products:"
+    printf '%s\n' "$expected" | sed 's/^/  /'
+}
+
+verify_linkage_test_covers_runtime_products
+
+if $DRY_RUN; then
+    echo "--dry-run: imports-in-sync check passed; skipping Linux build + ldd."
+    exit 0
+fi
 
 echo "Running on Linux - proceeding with linkage test..."