Make use of jextract build plugin from all gradle builds (TODO: make it a plugin)

Author: ktoso

Samples/SwiftAndJavaJarSampleLib/build.gradle

@@ -86,7 +86,6 @@ def swiftCheckValid = tasks.register("swift-check-valid", Exec) {
 def jextract = tasks.register("jextract", Exec) {
     description = "Generate Java wrappers for swift target"
     dependsOn swiftCheckValid
-    // dependsOn compileSwiftJExtractPlugin
 
     // only because we depend on "live developing" the plugin while using this project to test it
     inputs.file(new File(rootDir, "Package.swift"))
@@ -96,8 +95,7 @@ def jextract = tasks.register("jextract", Exec) {
     inputs.file(new File(projectDir, "Package.swift"))
 
     // monitor all targets/products which depend on the JExtract plugin
-    // swiftProductsWithJExtractPlugin().each {
-    ["MySwiftLibrary"].each {
+    swiftProductsWithJExtractPlugin().each {
         logger.info("[swift-java:jextract (Gradle)] Swift input target: ${it}")
         inputs.dir(new File(layout.projectDirectory.asFile, "Sources/${it}".toString()))
     }

Samples/SwiftKitSampleApp/build.gradle

@@ -12,9 +12,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+import groovy.json.JsonSlurper
 import org.swift.swiftkit.gradle.BuildUtils
 
 import java.nio.file.*
+import kotlinx.serialization.json.*
 
 plugins {
     id("build-logic.java-application-conventions")
@@ -34,26 +36,57 @@ java {
     }
 }
 
+def swiftProductsWithJExtractPlugin() {
+    def stdout = new ByteArrayOutputStream()
+    def stderr = new ByteArrayOutputStream()
+
+    def result = exec {
+        commandLine 'swift', 'package', 'describe', '--type', 'json'
+        standardOutput = stdout
+        errorOutput = stderr
+        ignoreExitValue = true
+    }
+
+    def jsonOutput = stdout.toString()
+
+    if (result.exitValue == 0) {
+        def json = new JsonSlurper().parseText(jsonOutput)
+        def products = json.targets
+                .findAll { target ->
+                    target.product_dependencies?.contains("JExtractSwiftPlugin")
+                }
+                .collectMany { target ->
+                    target.product_memberships ?: []
+                }
+        return products
+    } else {
+        logger.warn("Command failed: ${stderr.toString()}")
+        return []
+    }
+}
+
+
 def swiftCheckValid = tasks.register("swift-check-valid", Exec) {
     commandLine "swift"
     args("-version")
 }
 
 def jextract = tasks.register("jextract", Exec) {
-    description = "Builds swift sources, including swift-java source generation"
+    description = "Generate Java wrappers for swift target"
     dependsOn swiftCheckValid
-    // dependsOn compileSwiftJExtractPlugin
 
     // only because we depend on "live developing" the plugin while using this project to test it
     inputs.file(new File(rootDir, "Package.swift"))
     inputs.dir(new File(rootDir, "Sources"))
 
+    // If the package description changes, we should execute jextract again, maybe we added jextract to new targets
     inputs.file(new File(projectDir, "Package.swift"))
-    inputs.dir(new File(projectDir, "Sources"))
 
-    // TODO: we can use package describe --type json to figure out which targets depend on JExtractSwiftPlugin and will produce outputs
-    //       Avoid adding this directory, but create the expected one specifically for all targets
-    //       which WILL produce sources because they have the plugin
+    // monitor all targets/products which depend on the JExtract plugin
+    swiftProductsWithJExtractPlugin().each {
+        logger.info("[swift-java:jextract (Gradle)] Swift input target: ${it}")
+        inputs.dir(new File(layout.projectDirectory.asFile, "Sources/${it}".toString()))
+    }
     outputs.dir(layout.buildDirectory.dir("../.build/plugins/outputs/${layout.projectDirectory.asFile.getName().toLowerCase()}"))
 
     File baseSwiftPluginOutputsDir = layout.buildDirectory.dir("../.build/plugins/outputs/").get().asFile
@@ -69,7 +102,16 @@ def jextract = tasks.register("jextract", Exec) {
 
     workingDir = layout.projectDirectory
     commandLine "swift"
-    args("run", "swift-java", "jextract", "-v", "--log-level", "info") // TODO: pass log level from Gradle build
+    args("build") // since Swift targets which need to be jextract-ed have the jextract build plugin, we just need to build
+    // If we wanted to execute a specific subcommand, we can like this:
+    //     args("run",/*
+    //             "swift-java", "jextract",
+    //             "--swift-module", "MySwiftLibrary",
+    //             // java.package is obtained from the swift-java.config in the swift module
+    //             "--output-java", "${layout.buildDirectory.dir(".build/plugins/outputs/${layout.projectDirectory.asFile.getName().toLowerCase()}/JExtractSwiftPlugin/src/generated/java").get()}",
+    //             "--output-swift", "${layout.buildDirectory.dir(".build/plugins/outputs/${layout.projectDirectory.asFile.getName().toLowerCase()}/JExtractSwiftPlugin/Sources").get()}",
+    //             "--log-level", (logging.level <= LogLevel.INFO ? "debug" :  */"info")
+    //     )
 }
 
 // Add the java-swift generated Java sources

SwiftKit/src/main/java/org/swift/swiftkit/SwiftValueWitnessTable.java

@@ -71,7 +71,6 @@ public static MemorySegment fullTypeMetadata(MemorySegment typeMetadata) {
     public static MemorySegment valueWitnessTable(MemorySegment typeMetadata) {
         return fullTypeMetadata(typeMetadata)
                  .get(SwiftValueLayout.SWIFT_POINTER, SwiftValueWitnessTable.fullTypeMetadata$vwt$offset);
-//                .get(ValueLayout.ADDRESS, SwiftValueWitnessTable.fullTypeMetadata$vwt$offset);
     }