Allow configuring the library name to be loaded in swift-java.config (#682)

Author: ktoso

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator.swift

@@ -505,7 +505,7 @@ extension FFMSwift2JavaGenerator {
   func printClassConstants(printer: inout CodePrinter) {
     printer.print(
       """
-      static final String LIB_NAME = "\(swiftModuleName)";
+      static final String LIB_NAME = "\(config.nativeLibraryName ?? swiftModuleName)";
       static final Arena LIBRARY_ARENA = Arena.ofAuto();
       """
     )

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaBindingsPrinting.swift

@@ -100,7 +100,7 @@ extension JNISwift2JavaGenerator {
     printModuleClass(&printer) { printer in
       printer.print(
         """
-        static final String LIB_NAME = "\(swiftModuleName)";
+        static final String LIB_NAME = "\(config.nativeLibraryName ?? swiftModuleName)";
 
         static {
           System.loadLibrary(SwiftLibraries.LIB_NAME_SWIFT_JAVA);
@@ -189,7 +189,7 @@ extension JNISwift2JavaGenerator {
     printNominal(&printer, decl) { printer in
       printer.print(
         """
-        static final String LIB_NAME = "\(swiftModuleName)";
+        static final String LIB_NAME = "\(config.nativeLibraryName ?? swiftModuleName)";
 
         @SuppressWarnings("unused")
         private static final boolean INITIALIZED_LIBS = initializeLibs();

Sources/SwiftJavaConfigurationShared/Configuration.swift

@@ -32,6 +32,12 @@ public struct Configuration: Codable {
 
   public var swiftModule: String?
 
+  /// The name of the native library to load at runtime via `System.loadLibrary()`.
+  /// Defaults to the Swift module name when not set. Use this when the dynamic
+  /// library product has a different name than the module being exported
+  /// (e.g. the module is `MyLibrary` but the dylib is `MyLibrarySwiftJava` or something else).
+  public var nativeLibraryName: String?
+
   public var inputSwiftDirectory: String?
 
   public var outputSwiftDirectory: String?