Build and path handling adjustments to handle both old build system and swift-build (#740)

* adjust product name to survive new build system

The way we're looking up the swift-java "tool" in plugins uses the
target name "SwiftJavaTool" and that is correct in the natrive build
system.

In swift 6.4, and in Xcode, the swift-build build system is actually
naming them using product names: so swift-java. In order to have the
build work in BOTH build systems, we have to make the name be the
same... It's a workaround, but it seems to work.

This should resolve the failure

```
error: Build input file cannot be found: '/Users/ktoso/code/swift-java/Samples/JavaKitSampleApp/.build/out/Products/Debug/SwiftJavaTool'. Did you forget to declare this file as an output of a script phase or custom build rule which produces it?
```

that folks were reporting in #733 and in #281

* forward env to tool uses

* include swift-build paths in search paths

* more workarounds for nested swift-builds

Author: ktoso

.github/workflows/pull_request.yml

@@ -44,10 +44,12 @@ jobs:
   test-java:
     name: Test (Java) (${{ matrix.os_version }} swift:${{ matrix.swift_version }} jdk:${{matrix.jdk_vendor}})
     runs-on: ubuntu-latest
+    # Nightly builds are best-effort
+    continue-on-error: ${{ contains(matrix.swift_version, 'nightly') }}
     strategy:
       fail-fast: true
       matrix:
-        swift_version: ['6.2', '6.3']  # FIXME: reenable 'nightly' once snapshot toolchains are stable again
+        swift_version: ['6.2', '6.3', 'nightly']
         os_version: ['jammy']
         jdk_vendor: ['corretto']
     container:
@@ -136,10 +138,12 @@ jobs:
   test-swift:
     name: Test (Swift) (${{ matrix.os_version }} swift:${{ matrix.swift_version }} jdk:${{matrix.jdk_vendor}})
     runs-on: ubuntu-latest
+    # Nightly builds are best-effort
+    continue-on-error: ${{ contains(matrix.swift_version, 'nightly') }}
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ['6.1.3', '6.2', '6.3']  # FIXME: reenable 'nightly' once snapshot toolchains are stable again
+        swift_version: ['6.1.3', '6.2', '6.3', 'nightly']
         os_version: ['jammy']
         jdk_vendor: ['corretto']
     container:
@@ -186,10 +190,12 @@ jobs:
   build-swift-android:
     name: Sample SwiftJavaExtractJNISampleApp (Android) (swift:${{ matrix.swift_version }} android:${{matrix.sdk_triple}} NDK:${{matrix.ndk_version}})
     runs-on: ubuntu-22.04
+    # Nightly builds are best-effort
+    continue-on-error: ${{ contains(matrix.swift_version, 'nightly') }}
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ['nightly-6.3']  # FIXME: reenable 'nightly-main' once snapshot toolchains are stable again
+        swift_version: ['6.3']
         os_version: ['jammy']
         jdk_vendor: ['corretto']
         sdk_triple: ['aarch64-unknown-linux-android28', 'x86_64-unknown-linux-android28', 'armv7-unknown-linux-android28']
@@ -210,10 +216,12 @@ jobs:
   verify-samples:
     name: Sample ${{ matrix.sample_app }} (${{ matrix.os_version }} swift:${{ matrix.swift_version }} jdk:${{matrix.jdk_vendor}})
     runs-on: ubuntu-latest
+    # Nightly builds are best-effort
+    continue-on-error: ${{ contains(matrix.swift_version, 'nightly') }}
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ['6.1.3', '6.2', '6.3']  # FIXME: reenable 'nightly' once snapshot toolchains are stable again
+        swift_version: ['6.1.3', '6.2', '6.3', 'nightly']
         os_version: ['jammy']
         jdk_vendor: ['corretto']
         sample_app: [  # TODO: use a reusable-workflow to generate those names

BuildLogic/src/main/kotlin/build-logic.java-common-conventions.gradle.kts

@@ -81,9 +81,23 @@ fun javaLibraryPaths(rootDir: File): List<String> {
 
     val debugBuildOutputPaths = swiftBuildOutputPaths.map { "$it/debug" }
     val releaseBuildOutputPaths = swiftBuildOutputPaths.map { "$it/release" }
+
+    // swift-build layout (https://github.com/swiftlang/swift-build/issues/1363):
+    // .build/out/Products/<Config>[-<os>]/ — no triple, different config casing,
+    // OS suffix on Linux
+    val swiftBuildSystemConfigs = if (isLinux) {
+        listOf("Debug-linux", "Release-linux")
+    } else {
+        listOf("Debug", "Release")
+    }
+    val swiftBuildSystemRoots = listOf("$base.build/out/Products", "../../$base.build/out/Products")
+    val swiftBuildSystemPaths = swiftBuildSystemRoots.flatMap { root ->
+        swiftBuildSystemConfigs.map { config -> "$root/$config" }
+    }
+
     val swiftRuntimePaths = getSwiftRuntimeLibraryPaths()
 
-    return debugBuildOutputPaths + releaseBuildOutputPaths + swiftRuntimePaths
+    return debugBuildOutputPaths + releaseBuildOutputPaths + swiftBuildSystemPaths + swiftRuntimePaths
 }
 
 // Configure paths for native (Swift) libraries

BuildLogic/src/main/kotlin/utilities/javaLibraryPaths.kt

@@ -44,10 +44,22 @@ fun Project.javaLibraryPaths(rootDir: File?): List<String> {
         "${arch}-apple-macosx"
     }
 
-    val paths: List<String> = listOf("release", "debug").map { configuration ->
+    // Native build system: .build/<triple>/<config>/
+    val nativeBuildPaths: List<String> = listOf("release", "debug").map { configuration ->
         "${base}.build/${triple}/$configuration/"
     }
+
+    // swift-build: .build/out/Products/<Config>[-<os>]/
+    val swiftBuildConfigs = if (isLinux) {
+        listOf("Debug-linux", "Release-linux")
+    } else {
+        listOf("Debug", "Release")
+    }
+    val swiftBuildPaths: List<String> = swiftBuildConfigs.map { config ->
+        "${base}.build/out/Products/$config/"
+    }
+
     val swiftRuntimePaths = swiftRuntimeLibraryPaths()
 
-    return paths + swiftRuntimePaths
+    return nativeBuildPaths + swiftBuildPaths + swiftRuntimePaths
 }

Package.swift

@@ -61,7 +61,7 @@ let package = Package(
 
     .executable(
       name: "swift-java",
-      targets: ["SwiftJavaTool"]
+      targets: ["swift-java"]
     ),
 
     .library(
@@ -224,7 +224,7 @@ let package = Package(
       name: "SwiftJavaPlugin",
       capability: .buildTool(),
       dependencies: [
-        "SwiftJavaTool"
+        "swift-java"
       ]
     ),
 
@@ -289,7 +289,7 @@ let package = Package(
     ),
 
     .executableTarget(
-      name: "SwiftJavaTool",
+      name: "swift-java",
       dependencies: [
         .product(name: "SwiftBasicFormat", package: "swift-syntax"),
         .product(name: "SwiftSyntax", package: "swift-syntax"),
@@ -304,6 +304,10 @@ let package = Package(
         "SwiftJavaShared",
         "SwiftJavaConfigurationShared",
       ],
+      // Keep existing directory name while the target is renamed; see
+      // https://github.com/swiftlang/swift-java/issues/733 for why the
+      // target name must match the product name.
+      path: "Sources/SwiftJavaTool",
       swiftSettings: [
         .swiftLanguageMode(.v5),
         .enableUpcomingFeature("BareSlashRegexLiterals"),
@@ -362,7 +366,7 @@ let package = Package(
       name: "JExtractSwiftPlugin",
       capability: .buildTool(),
       dependencies: [
-        "SwiftJavaTool"
+        "swift-java"
       ]
     ),
 

Plugins/JExtractSwiftPlugin/JExtractSwiftPlugin.swift

@@ -29,7 +29,7 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
   var verbose: Bool = getEnvironmentBool("SWIFT_JAVA_VERBOSE")
 
   func createBuildCommands(context: PluginContext, target: Target) throws -> [Command] {
-    let toolURL = try context.tool(named: "SwiftJavaTool").url
+    let toolURL = try context.tool(named: "swift-java").url
 
     var commands: [Command] = []
 
@@ -171,6 +171,7 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
         displayName: "Generate Java wrappers for Swift types",
         executable: toolURL,
         arguments: arguments,
+        environment: ProcessInfo.processInfo.environment,
         inputFiles: [configFile] + swiftFiles,
         outputFiles: jextractOutputFiles,
       )
@@ -203,9 +204,8 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
     let GradleUserHome = "GRADLE_USER_HOME"
     let gradleUserHomePath = gradleUserHome.path(percentEncoded: false)
     log("Prepare command: :SwiftKitCore:build in \(GradleUserHome)=\(gradleUserHomePath)")
-    var gradlewEnvironment = ProcessInfo.processInfo.environment
-    gradlewEnvironment[GradleUserHome] = gradleUserHomePath
-    log("Forward environment: \(gradlewEnvironment)")
+    var environment = ProcessInfo.processInfo.environment
+    environment[GradleUserHome] = gradleUserHomePath
 
     let gradlewURL = swiftJavaDirectory.appending(path: "gradlew")
     let gradleExecutable: URL
@@ -256,6 +256,7 @@ struct JExtractSwiftBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
         displayName: "Build SwiftKitCore, compile Java callbacks, and generate Swift wrappers",
         executable: toolURL,
         arguments: javaCallbacksArguments,
+        environment: environment,
         inputFiles: outputSwiftFiles + [swiftJavaDirectory],
         outputFiles: [javaCallbacksSwiftOutput],
       )

Plugins/SwiftJavaPlugin/SwiftJavaPlugin.swift

@@ -31,7 +31,7 @@ struct SwiftJavaBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
     log("Create build commands for target '\(target.name)'")
     guard let sourceModule = target.sourceModule else { return [] }
 
-    let executable = try context.tool(named: "SwiftJavaTool").url
+    let executable = try context.tool(named: "swift-java").url
     var commands: [Command] = []
 
     // Note: Target doesn't have a directoryURL counterpart to directory,
@@ -165,7 +165,7 @@ struct SwiftJavaBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
           arguments: ["resolve"]
             + argumentsOutputDirectory(context: context, generated: false)
             + argumentsSwiftModule(sourceModule: sourceModule),
-          environment: [:],
+          environment: ProcessInfo.processInfo.environment,
           inputFiles: [configFile],
           outputFiles: fetchDependenciesOutputFiles
         )
@@ -192,6 +192,7 @@ struct SwiftJavaBuildToolPlugin: SwiftJavaPluginProtocol, BuildToolPlugin {
           executable: executable,
           arguments: ["wrap-java"]
             + arguments,
+          environment: ProcessInfo.processInfo.environment,
           inputFiles: compiledClassFiles + fetchDependenciesOutputFiles + [configFile],
           outputFiles: outputSwiftFiles
         )

SwiftKitCore/build.gradle.kts

@@ -86,6 +86,19 @@ val compileSwift = tasks.register<Exec>("compileSwift") {
     commandLine("swift")
     // FIXME: disable prebuilts until swift-syntax isn't broken on 6.2 anymore: https://github.com/swiftlang/swift-java/issues/418
     args("build", "--disable-experimental-prebuilts", "--target", "SwiftRuntimeFunctions")
+
+    // When this task runs inside an outer swift-build-driven invocation (e.g.
+    // JExtractSwiftPlugin -> java-callbacks-build -> gradle -> here) the outer
+    // build leaks Xcode-style build settings (SDKROOT=/, TOOLCHAINS, SDK_*,
+    // SWIFTC_PASS_*) into the subprocess environment, which breaks the nested
+    // swift build with "unable to resolve run destination SDK: '/'". Strip
+    // them so the inner invocation resolves its own defaults.
+    listOf(
+        "SDKROOT", "SDK_DIR", "SDK_DIR_linux", "SDK_NAME", "SDK_NAMES",
+        "SDK_VERSION", "SDK_VERSION_ACTUAL", "SDK_VERSION_MAJOR", "SDK_VERSION_MINOR",
+        "SDK_STAT_CACHE_DIR", "SDK_STAT_CACHE_ENABLE", "SDK_STAT_CACHE_PATH",
+        "SWIFTC_PASS_SDKROOT", "SWIFTC_PASS_SYSROOT", "TOOLCHAINS",
+    ).forEach { environment.remove(it) }
 }
 tasks.build {
     dependsOn(compileSwift)

SwiftKitFFM/build.gradle.kts

@@ -89,6 +89,19 @@ val compileSwift = tasks.register<Exec>("compileSwift") {
     commandLine("swift")
     // FIXME: disable prebuilts until swift-syntax isn't broken on 6.2 anymore: https://github.com/swiftlang/swift-java/issues/418
     args("build", "--disable-experimental-prebuilts", "--target", "SwiftRuntimeFunctions")
+
+    // When this task runs inside an outer swift-build-driven invocation (e.g.
+    // JExtractSwiftPlugin -> java-callbacks-build -> gradle -> here) the outer
+    // build leaks Xcode-style build settings (SDKROOT=/, TOOLCHAINS, SDK_*,
+    // SWIFTC_PASS_*) into the subprocess environment, which breaks the nested
+    // swift build with "unable to resolve run destination SDK: '/'". Strip
+    // them so the inner invocation resolves its own defaults.
+    listOf(
+        "SDKROOT", "SDK_DIR", "SDK_DIR_linux", "SDK_NAME", "SDK_NAMES",
+        "SDK_VERSION", "SDK_VERSION_ACTUAL", "SDK_VERSION_MAJOR", "SDK_VERSION_MINOR",
+        "SDK_STAT_CACHE_DIR", "SDK_STAT_CACHE_ENABLE", "SDK_STAT_CACHE_PATH",
+        "SWIFTC_PASS_SDKROOT", "SWIFTC_PASS_SYSROOT", "TOOLCHAINS",
+    ).forEach { environment.remove(it) }
 }
 tasks.build {
     dependsOn(compileSwift)