Return type overrides

buildSrc/src/main/groovy/java-gi.library-conventions.gradle

@@ -31,7 +31,7 @@ dependencies {
 }
 
 group = 'io.github.jwharm.javagi'
-version = '0.8.0'
+version = '0.8.1-SNAPSHOT'
 
 java {
     if (! System.getenv('CI')) {

buildSrc/src/main/java/io/github/jwharm/javagi/generator/Patch.java

@@ -70,17 +70,12 @@ default void removeType(Repository repo, String type) {
             System.out.println("Did not remove " + type + ": Not found");
     }
 
-    default void setReturnType(Repository repo, String type, String name, String typeName, String typeCType, String defaultReturnValue, String doc) {
-        setReturnType(findVirtualMethod(repo, type, name), typeName, typeCType, defaultReturnValue, doc);
-        setReturnType(findMethod(repo, type, name), typeName, typeCType, defaultReturnValue, doc);
-    }
-
-    private void setReturnType(Method m, String typeName, String typeCType, String defaultReturnValue, String doc) {
+    default void setReturnType(Method m, String typeName, String typeCType, String defaultReturnValue, String doc) {
         if (m == null) {
             return;
         }
         ReturnValue rv = m.returnValue;
-        rv.type = new Type(rv, typeName, typeCType);
+        rv.overrideReturnType = new Type(rv, typeName, typeCType);
         rv.overrideReturnValue = defaultReturnValue;
         if (doc != null) {
             rv.doc = new Doc(rv, "1");

buildSrc/src/main/java/io/github/jwharm/javagi/model/GirElement.java

@@ -74,6 +74,10 @@ public GirElement(GirElement parent) {
         previouslyCreated = this;
     }
 
+    public Type getType() {
+        return this.type;
+    }
+
     public Namespace getNamespace() {
         if (this instanceof Repository r) {
             return r.namespace;

buildSrc/src/main/java/io/github/jwharm/javagi/model/Method.java

@@ -91,7 +91,7 @@ public String getMethodDeclaration() {
             if (this instanceof Constructor) {
                 writer.write("MemorySegment");
             } else {
-                getReturnValue().writeType(writer, true);
+                getReturnValueOverride().writeType(writer, true);
             }
 
             // Method name
@@ -168,6 +168,8 @@ public void generate(SourceWriter writer) throws IOException {
             return;
         }
 
+        ReturnValue returnValue = getReturnValueOverride();
+
         writer.write("\n");
 
         // Documentation
@@ -193,11 +195,6 @@ public void generate(SourceWriter writer) throws IOException {
         // Check for unsupported platforms
         generatePlatformCheck(writer);
 
-        // FunctionDescriptor of the native function signature
-        writer.write("FunctionDescriptor _fdesc = ");
-        boolean varargs = generateFunctionDescriptor(writer);
-        writer.write(";\n");
-
         // Generate try-with-resources?
         boolean hasScope = allocatesMemory();
         if (hasScope) {
@@ -216,8 +213,8 @@ public void generate(SourceWriter writer) throws IOException {
         }
 
         // Variable declaration for return value
-        String carrierType = Conversions.getCarrierType(getReturnValue().type);
-        if (! (returnValue.type != null && returnValue.type.isVoid())) {
+        String carrierType = returnValue.getCarrierType();
+        if (! returnValue.isVoid()) {
             writer.write(carrierType + " _result;\n");
         }
 
@@ -239,13 +236,18 @@ public void generate(SourceWriter writer) throws IOException {
             writer.increaseIndent();
         }
 
+        // FunctionDescriptor of the native function signature
+        writer.write("FunctionDescriptor _fdesc = ");
+        boolean varargs = generateFunctionDescriptor(writer);
+        writer.write(";\n");
+
         // Log the method call
         log(cIdentifier, writer);
 
         // Generate the return type
-        if (! (returnValue.type != null && returnValue.type.isVoid())) {
+        if (! (getReturnValue().type != null && getReturnValue().type.isVoid())) {
             writer.write("_result = (");
-            writer.write(carrierType);
+            writer.write(Conversions.getCarrierType(getReturnValue().type));
             writer.write(") ");
         }
 
@@ -258,6 +260,11 @@ public void generate(SourceWriter writer) throws IOException {
         }
         writer.write(");\n");
 
+        // Set default return value (if applicable)
+        if (getReturnValue().overrideReturnValue != null) {
+            writer.write("_result = " + getReturnValue().overrideReturnValue + ";\n");
+        }
+
         // End of if/else block for virtual/named method call
         if (linkedVirtualMethod != null) {
             writer.decreaseIndent();
@@ -330,6 +337,16 @@ public ReturnValue getReturnValue() {
         return returnValue;
     }
 
+    private ReturnValue getReturnValueOverride() {
+        if (linkedVirtualMethod != null) {
+            if (returnValue.getType() != null && returnValue.isVoid()
+                    && linkedVirtualMethod.returnValue.getType() != null) {
+                return linkedVirtualMethod.returnValue;
+            }
+        }
+        return returnValue;
+    }
+
     @Override
     public void setReturnValue(ReturnValue rv) {
         this.returnValue = rv;

buildSrc/src/main/java/io/github/jwharm/javagi/model/ReturnValue.java

@@ -27,13 +27,15 @@
 public class ReturnValue extends Parameter {
 
     public boolean returnsFloatingReference;
+    public Type overrideReturnType;
     public String overrideReturnValue;
 
     public ReturnValue(GirElement parent, String transferOwnership, String nullable, String scope) {
         super(parent, null, transferOwnership, nullable,
                 null, null, null, null, null, null, scope);
 
         returnsFloatingReference = false;
+        overrideReturnType = null;
         overrideReturnValue = null;
     }
 
@@ -85,16 +87,11 @@ public void generate(SourceWriter writer) throws IOException {
      * @throws IOException Thrown when an error occurs while writing
      */
     public void generateReturnStatement(SourceWriter writer) throws IOException {
+        Type type = overrideReturnType == null ? this.type : overrideReturnType;
         if (type != null && type.isVoid()) {
             return;
         }
 
-        // Return value hard-coded in PatchSet?
-        if (overrideReturnValue != null) {
-            writer.write("return " + overrideReturnValue + ";\n");
-            return;
-        }
-
         // When transfer-ownership="none", we must take a reference
         if (isGObject() && "none".equals(transferOwnership) && (! parent.name.equals("ref"))) {
 
@@ -142,4 +139,21 @@ public void generateReturnStatement(SourceWriter writer) throws IOException {
             writer.write(";\n");
         }
     }
+
+    @Override
+    public Type getType() {
+        return overrideReturnType != null ? overrideReturnType : super.getType();
+    }
+
+    public boolean isVoid() {
+        if (overrideReturnType != null)
+            return (overrideReturnType.isVoid());
+        return (type != null && type.isVoid());
+    }
+
+    public String getCarrierType() {
+        if (overrideReturnType != null)
+            return Conversions.getCarrierType(overrideReturnType);
+        return Conversions.getCarrierType(type);
+    }
 }

buildSrc/src/main/java/io/github/jwharm/javagi/model/Variable.java

@@ -80,6 +80,7 @@ private String getAnnotations(Type type, boolean writeAnnotations) {
     }
 
     private String getType(boolean writeAnnotations) {
+        Type type = getType();
 
         if (type != null && type.isActuallyAnArray())
             return getAnnotations(type, writeAnnotations) + getType(type) + "[]";
@@ -205,6 +206,8 @@ private String marshalJavaArrayToNative(Array array, String identifier) {
     }
 
     private String marshalNativeToJava(String identifier, boolean upcall) {
+        Type type = getType();
+
         if (type != null && type.cType != null && type.cType.equals("gfloat**"))
             return "null /* unsupported */";
 

buildSrc/src/main/java/io/github/jwharm/javagi/model/VirtualMethod.java

@@ -76,14 +76,10 @@ public void generate(SourceWriter writer) throws IOException {
             writer.write("MemorySegment _gerror = _arena.allocate(ValueLayout.ADDRESS);\n");
         }
 
-        // Function descriptor
-        writer.write("FunctionDescriptor _fdesc = ");
-        generateFunctionDescriptor(writer);
-        writer.write(";\n");
-
         // Variable declaration for return value
-        String carrierType = Conversions.getCarrierType(getReturnValue().type);
-        if (! (returnValue.type != null && returnValue.type.isVoid())) {
+        // Variable declaration for return value
+        String carrierType = returnValue.getCarrierType();
+        if (! returnValue.isVoid()) {
             writer.write(carrierType + " _result;\n");
         }
 
@@ -127,6 +123,13 @@ public void generate(SourceWriter writer) throws IOException {
     public void generateInvocation(SourceWriter writer) throws IOException {
         Record classStruct = null;
         String className = null;
+
+        // FunctionDescriptor of the native function signature
+        writer.write("FunctionDescriptor _fdesc = ");
+        boolean varargs = generateFunctionDescriptor(writer);
+        writer.write(";\n");
+
+        // Lookup the function table
         if (parent instanceof Class c) {
             classStruct = c.classStruct;
             className = c.javaName;
@@ -137,6 +140,7 @@ public void generateInvocation(SourceWriter writer) throws IOException {
         if (classStruct == null) {
             throw new IOException("Cannot find typestruct for " + parent.name);
         }
+
         writer.write("MemorySegment _func = Overrides.lookupVirtualMethodParent(handle(), " + classStruct.javaName + ".getMemoryLayout(), \"" + name + "\"");
         if (parent instanceof Interface) {
             writer.write(", " + className + ".getType()");
@@ -167,5 +171,10 @@ public void generateInvocation(SourceWriter writer) throws IOException {
             parameters.marshalJavaToNative(writer, throws_);
         }
         writer.write(");\n");
+
+        // Set default return value (if applicable)
+        if (returnValue.overrideReturnValue != null) {
+            writer.write("_result = " + returnValue.overrideReturnValue + ";\n");
+        }
     }
 }

buildSrc/src/main/java/io/github/jwharm/javagi/patches/GioPatch.java

@@ -16,8 +16,6 @@ public void patch(Repository repo) {
         renameMethod(repo, "BufferedInputStream", "read_byte", "read_int");
         renameMethod(repo, "IOModule", "load", "load_module");
 
-        setReturnType(repo, "ActionGroup", "activate_action", "gboolean", "gboolean", "true", "always %TRUE");
-
         // Override of static method
         removeVirtualMethod(repo, "SocketControlMessage", "get_type");
 

buildSrc/src/main/java/io/github/jwharm/javagi/patches/GstAudioPatch.java

@@ -9,8 +9,8 @@ public class GstAudioPatch implements Patch {
 
     @Override
     public void patch(Repository repo) {
-        // Override with different return type
-        setReturnType(repo, "AudioSink", "stop", "gboolean", "gboolean", "true", "always %TRUE");
+        // Override with different return type (BaseSink.stop() returns boolean)
+        setReturnType(findVirtualMethod(repo, "AudioSink", "stop"), "gboolean", "gboolean", "1", "always %TRUE");
         // A GstFraction cannot automatically be put into a GValue
         removeProperty(repo, "AudioAggregator", "output-buffer-duration-fraction");
 

buildSrc/src/main/java/io/github/jwharm/javagi/patches/GstVideoPatch.java

@@ -7,6 +7,6 @@ public class GstVideoPatch implements Patch {
 
     @Override
     public void patch(Repository repo) {
-        setReturnType(repo, "VideoOverlay", "set_render_rectangle", "none", "void", null, null);
+        setReturnType(findVirtualMethod(repo, "VideoOverlay", "set_render_rectangle"), "gboolean", "gboolean", "1", null);
     }
 }

buildSrc/src/main/java/io/github/jwharm/javagi/patches/GtkPatch.java

@@ -15,8 +15,9 @@ public void patch(Repository repo) {
         if (repo.module.platform != Platform.WINDOWS)
             renameMethod(repo, "PrintUnixDialog", "get_settings", "get_print_settings");
         renameMethod(repo, "Widget", "activate", "activate_widget");
+        renameMethod(repo, "Widget", "activate_action", "activate_action_if_exists");
 
-        setReturnType(repo, "MediaStream", "play", "none", "void", null, null);
+        setReturnType(findMethod(repo, "MediaStream", "play"), "gboolean", "gboolean", "1", null);
 
         // These calls return floating references
         setReturnFloating(findMethod(repo, "FileFilter", "to_gvariant"));

buildSrc/src/main/java/io/github/jwharm/javagi/patches/SoupPatch.java

@@ -7,6 +7,6 @@ public class SoupPatch implements Patch {
 
     @Override
     public void patch(Repository repo) {
-        setReturnType(repo, "AuthDomain", "challenge", "none", "void", null, null);
+        setReturnType(findMethod(repo, "AuthDomain", "challenge"), "utf8", "char*", "null", "Always {@code null}");
     }
 }