Dynamically load libjvm rather than requiring it at build time (#8)

* Dynamically load libjvm rather than requiring it at build time

* Update formatting

* Add amazonlinux2 back to CI and formatting fix

* Update CI to include macOS and Windows and not pre-install Java on Linux

* Update dynamic library loading to support Windows

* Add imports for Windows

* Cleanup and compact

* Fix fomatting and cleanup symbol loading

Author: marcprux

.github/workflows/pull_request.yml

@@ -12,29 +12,13 @@ jobs:
     name: Test
     uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
     with:
-      # TODO: need to pre-install Java
-      enable_windows_checks: false
-      # TODO: need to pre-install Java
-      enable_macos_checks: false
+      enable_windows_checks: true
+      windows_swift_versions: '["nightly-main"]'
+      enable_macos_checks: true
       enable_ios_checks: false
       enable_linux_checks: true
-      linux_os_versions: '["bookworm", "jammy", "noble", "rhel-ubi9"]'
+      linux_os_versions: '["amazonlinux2", "bookworm", "noble", "jammy", "rhel-ubi9"]'
       linux_exclude_swift_versions: "[{\"swift_version\": \"5.9\"}, {\"swift_version\": \"5.10\"}]"
-      linux_pre_build_command: |
-        if command -v apt-get >/dev/null 2>&1 ; then # bookworm, noble, jammy
-          if command -v sudo &> /dev/null && [ "$EUID" -ne 0 ]; then
-            sudo apt-get update -y
-            sudo apt-get install -y default-jdk
-          else
-            apt-get update -y
-            apt-get install -y default-jdk
-          fi
-        elif command -v yum >/dev/null 2>&1 ; then # amazonlinux2, rhel-ubi9
-          # TODO: amazonlinux2 needs more help finding JAVA_HOME
-          yum update -y
-          yum install -y java-devel
-        fi
-
       enable_android_sdk_build: true
       enable_android_sdk_checks: true
   soundness:

Package.swift

@@ -1,133 +1,7 @@
 // swift-tools-version: 6.0
 // The swift-tools-version declares the minimum version of Swift required to build this package.
-
-import Foundation
 import PackageDescription
 
-// Note: the JAVA_HOME environment variable must be set to point to where
-// Java is installed, e.g.,
-//   Library/Java/JavaVirtualMachines/openjdk-21.jdk/Contents/Home.
-func findJavaHome() -> String {
-  if let home = ProcessInfo.processInfo.environment["JAVA_HOME"] {
-    return home
-  }
-
-  // This is a workaround for envs (some IDEs) which have trouble with
-  // picking up env variables during the build process
-  let path = "\(FileManager.default.homeDirectoryForCurrentUser.path()).java_home"
-  if let home = try? String(contentsOfFile: path, encoding: .utf8) {
-    if let lastChar = home.last, lastChar.isNewline {
-      return String(home.dropLast())
-    }
-
-    return home
-  }
-
-  if let home = getJavaHomeFromLibexecJavaHome(),
-    !home.isEmpty
-  {
-    return home
-  }
-
-  if let home = getJavaHomeFromSDKMAN() {
-    return home
-  }
-
-  if let home = getJavaHomeFromPath() {
-    return home
-  }
-
-  if ProcessInfo.processInfo.environment["SPI_PROCESSING"] == "1"
-    && ProcessInfo.processInfo.environment["SPI_BUILD"] == nil
-  {
-    return ""
-  }
-  fatalError("Please set the JAVA_HOME environment variable to point to where Java is installed.")
-}
-
-/// On MacOS we can use the java_home tool as a fallback if we can't find JAVA_HOME environment variable.
-func getJavaHomeFromLibexecJavaHome() -> String? {
-  let task = Process()
-  task.executableURL = URL(fileURLWithPath: "/usr/libexec/java_home")
-
-  guard FileManager.default.fileExists(atPath: task.executableURL!.path) else {
-    return nil
-  }
-
-  let pipe = Pipe()
-  task.standardOutput = pipe
-  task.standardError = pipe
-
-  do {
-    try task.run()
-    task.waitUntilExit()
-
-    let data = pipe.fileHandleForReading.readDataToEndOfFile()
-    let output = String(data: data, encoding: .utf8)?.trimmingCharacters(in: .whitespacesAndNewlines)
-
-    if task.terminationStatus == 0 {
-      return output
-    } else {
-      return nil
-    }
-  } catch {
-    return nil
-  }
-}
-
-func getJavaHomeFromSDKMAN() -> String? {
-  let home = FileManager.default.homeDirectoryForCurrentUser
-    .appendingPathComponent(".sdkman/candidates/java/current")
-
-  let javaBin = home.appendingPathComponent("bin/java").path
-  if FileManager.default.isExecutableFile(atPath: javaBin) {
-    return home.path
-  }
-  return nil
-}
-
-func getJavaHomeFromPath() -> String? {
-  let task = Process()
-  task.executableURL = URL(fileURLWithPath: "/usr/bin/which")
-  task.arguments = ["java"]
-
-  let pipe = Pipe()
-  task.standardOutput = pipe
-
-  do {
-    try task.run()
-    task.waitUntilExit()
-    guard task.terminationStatus == 0 else { return nil }
-
-    let data = pipe.fileHandleForReading.readDataToEndOfFile()
-    guard
-      let javaPath = String(data: data, encoding: .utf8)?
-        .trimmingCharacters(in: .whitespacesAndNewlines),
-      !javaPath.isEmpty
-    else { return nil }
-
-    let resolved = URL(fileURLWithPath: javaPath).resolvingSymlinksInPath()
-    return
-      resolved
-      .deletingLastPathComponent()
-      .deletingLastPathComponent()
-      .path
-  } catch {
-    return nil
-  }
-}
-
-let javaHome = findJavaHome()
-
-let javaIncludePath = "\(javaHome)/include"
-#if os(Linux)
-let javaPlatformIncludePath = "\(javaIncludePath)/linux"
-#elseif os(macOS)
-let javaPlatformIncludePath = "\(javaIncludePath)/darwin"
-#elseif os(Windows)
-let javaPlatformIncludePath = "\(javaIncludePath)/win32"
-#endif
-
 let package = Package(
   name: "swift-java-jni-core",
   products: [
@@ -138,57 +12,20 @@ let package = Package(
   ],
   targets: [
     .target(
-      name: "CSwiftJavaJNI",
-      cSettings: [
-        .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"], .when(platforms: [.macOS, .linux, .windows]))
-      ],
-      swiftSettings: [
-        .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"], .when(platforms: [.macOS, .linux, .windows]))
-      ],
-      linkerSettings: [
-        .linkedLibrary("log", .when(platforms: [.android]))
-      ]
+      name: "CSwiftJavaJNI"
     ),
 
     .target(
       name: "SwiftJavaJNICore",
       dependencies: [
         "CSwiftJavaJNI"
-      ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5),
-        .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"], .when(platforms: [.macOS, .linux, .windows])),
-      ],
-      linkerSettings: [
-        .unsafeFlags(
-          [
-            "-L\(javaHome)/lib/server",
-            "-Xlinker", "-rpath",
-            "-Xlinker", "\(javaHome)/lib/server",
-          ],
-          .when(platforms: [.linux, .macOS])
-        ),
-        .unsafeFlags(
-          [
-            "-L\(javaHome)/lib"
-          ],
-          .when(platforms: [.windows])
-        ),
-        .linkedLibrary(
-          "jvm",
-          .when(platforms: [.linux, .macOS, .windows])
-        ),
       ]
     ),
 
     .testTarget(
       name: "SwiftJavaJNICoreTests",
       dependencies: [
         "SwiftJavaJNICore"
-      ],
-      swiftSettings: [
-        .swiftLanguageMode(.v5),
-        .unsafeFlags(["-I\(javaIncludePath)", "-I\(javaPlatformIncludePath)"], .when(platforms: [.macOS, .linux, .windows])),
       ]
     ),
   ]