mapstruct · sjaakd · Jul 16, 2020 · Jul 7, 2020
diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/common/Type.java b/processor/src/main/java/org/mapstruct/ap/internal/model/common/Type.java
@@ -482,6 +482,24 @@ public boolean isAssignableTo(Type other) {
         return typeUtils.isAssignable( typeMirrorToMatch, other.typeMirror );
     }
 
+    /**
+     * Whether this type is raw assignable to the given other type. We can't make a verdict on typevars,
+     * they need to be resolved first.
+     *
+     * @param other The other type.
+     *
+     * @return {@code true} if and only if this type is assignable to the given other type.
+     */
+    public boolean isRawAssignableTo(Type other) {
+        if ( isTypeVar() || other.isTypeVar() ) {
+            return true;
+        }
+        if ( equals( other ) ) {
+            return true;
+        }
+        return typeUtils.isAssignable( typeUtils.erasure( typeMirror ), typeUtils.erasure( other.typeMirror ) );
+    }
+
     /**
      * getPropertyReadAccessors
      *

diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/source/Method.java b/processor/src/main/java/org/mapstruct/ap/internal/model/source/Method.java
@@ -187,4 +187,18 @@ public interface Method {
     default boolean isMappingTargetAssignableToReturnType() {
         return isUpdateMethod() && getResultType().isAssignableTo( getReturnType() );
     }
+
+    /**
+     * @return the first source type, intended for mapping methods from single source to target
+     */
+    default Type getMappingSourceType() {
+        return getSourceParameters().get( 0 ).getType();
+    }
+
+    /**
+     * @return the short name for error messages
+     */
+    default String shortName() {
+        return getResultType().getName() + ":" + getName() + "(" + getMappingSourceType().getName() + ")";
+    }
 }
diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/source/SourceMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/source/SourceMethod.java
@@ -294,7 +294,7 @@ public boolean inverses(SourceMethod method) {
         return method.getDeclaringMapper() == null
             && method.isAbstract()
             && getSourceParameters().size() == 1 && method.getSourceParameters().size() == 1
-            && first( getSourceParameters() ).getType().isAssignableTo( method.getResultType() )
+            && getMappingSourceType().isAssignableTo( method.getResultType() )
             && getResultType().isAssignableTo( first( method.getSourceParameters() ).getType() );
     }
 
@@ -326,7 +326,7 @@ public Parameter getTargetTypeParameter() {
     public boolean isIterableMapping() {
         if ( isIterableMapping == null ) {
             isIterableMapping = getSourceParameters().size() == 1
-                && first( getSourceParameters() ).getType().isIterableType()
+                && getMappingSourceType().isIterableType()
                 && getResultType().isIterableType();
         }
         return isIterableMapping;
@@ -335,17 +335,17 @@ && first( getSourceParameters() ).getType().isIterableType()
     public boolean isStreamMapping() {
         if ( isStreamMapping == null ) {
             isStreamMapping = getSourceParameters().size() == 1
-                && ( first( getSourceParameters() ).getType().isIterableType() && getResultType().isStreamType()
-                    || first( getSourceParameters() ).getType().isStreamType() && getResultType().isIterableType()
-                    || first( getSourceParameters() ).getType().isStreamType() && getResultType().isStreamType() );
+                && ( getMappingSourceType().isIterableType() && getResultType().isStreamType()
+                    || getMappingSourceType().isStreamType() && getResultType().isIterableType()
+                    || getMappingSourceType().isStreamType() && getResultType().isStreamType() );
         }
         return isStreamMapping;
     }
 
     public boolean isMapMapping() {
         if ( isMapMapping == null ) {
             isMapMapping = getSourceParameters().size() == 1
-                && first( getSourceParameters() ).getType().isMapType()
+                && getMappingSourceType().isMapType()
                 && getResultType().isMapType();
         }
         return isMapMapping;

diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/source/builtin/BuiltInMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/source/builtin/BuiltInMethod.java
@@ -67,21 +67,13 @@ public boolean matches(List<Type> sourceTypes, Type targetType) {
 
         Type sourceType = first( sourceTypes );
 
-        if ( getReturnType().isAssignableTo( targetType.erasure() )
-            && sourceType.erasure().isAssignableTo( getParameter().getType() ) ) {
-            return doTypeVarsMatch( sourceType, targetType );
-        }
-        if ( getReturnType().getFullyQualifiedName().equals( "java.lang.Object" )
-            && sourceType.erasure().isAssignableTo( getParameter().getType() ) ) {
-            // return type could be a type parameter T
-            return doTypeVarsMatch( sourceType, targetType );
-        }
-        if ( getReturnType().isAssignableTo( targetType.erasure() )
-            &&  getParameter().getType().getFullyQualifiedName().equals( "java.lang.Object" ) ) {
-            // parameter type could be a type parameter T
-            return doTypeVarsMatch( sourceType, targetType );
+        Type returnType = getReturnType().resolveTypeVarToType( sourceType, getParameter().getType()  );
+        if ( returnType == null ) {
+            return false;
         }
-        return false;
+
+        return returnType.isAssignableTo( targetType )
+            && sourceType.erasure().isAssignableTo( getParameter().getType() );
     }
 
     @Override

diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/source/builtin/JaxbElemToValue.java b/processor/src/main/java/org/mapstruct/ap/internal/model/source/builtin/JaxbElemToValue.java
@@ -5,15 +5,16 @@
  */
 package org.mapstruct.ap.internal.model.source.builtin;
 
+import static org.mapstruct.ap.internal.util.Collections.asSet;
+
 import java.util.Set;
+
 import javax.xml.bind.JAXBElement;
 
 import org.mapstruct.ap.internal.model.common.Parameter;
 import org.mapstruct.ap.internal.model.common.Type;
 import org.mapstruct.ap.internal.model.common.TypeFactory;
 
-import static org.mapstruct.ap.internal.util.Collections.asSet;
-
 /**
  * @author Sjaak Derksen
  */
@@ -24,8 +25,9 @@ public class JaxbElemToValue extends BuiltInMethod {
     private final Set<Type> importTypes;
 
     public JaxbElemToValue(TypeFactory typeFactory) {
-        this.parameter = new Parameter( "element", typeFactory.getType( JAXBElement.class ) );
-        this.returnType = typeFactory.getType( Object.class );
+        Type type = typeFactory.getType(  JAXBElement.class  );
+        this.parameter = new Parameter( "element", type );
+        this.returnType = type.getTypeParameters().get( 0 );
         this.importTypes = asSet( parameter.getType() );
     }
 

diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/SelectedMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/SelectedMethod.java
@@ -6,6 +6,7 @@
 package org.mapstruct.ap.internal.model.source.selector;
 
 import java.util.List;
+import java.util.Objects;
 
 import org.mapstruct.ap.internal.model.common.ParameterBinding;
 import org.mapstruct.ap.internal.model.source.Method;
@@ -39,4 +40,21 @@ public void setParameterBindings(List<ParameterBinding> parameterBindings) {
     public String toString() {
         return method.toString();
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if ( this == o ) {
+            return true;
+        }
+        if ( o == null || getClass() != o.getClass() ) {
+            return false;
+        }
+        SelectedMethod<?> that = (SelectedMethod<?>) o;
+        return method.equals( that.method );
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash( method );
+    }
 }
diff --git a/...src/main/java/org/mapstruct/ap/internal/model/source/selector/XmlElementDeclSelector.java b/...src/main/java/org/mapstruct/ap/internal/model/source/selector/XmlElementDeclSelector.java
@@ -69,7 +69,7 @@ public <T extends Method> List<SelectedMethod<T>> getMatchingMethods(Method mapp
             }
 
             String name = xmlElementDecl.name().get();
-            TypeMirror scope = xmlElementDecl.scope().get();
+            TypeMirror scope = xmlElementDecl.scope().getValue();
 
             boolean nameIsSetAndMatches = name != null && name.equals( xmlElementRefInfo.nameValue() );
             boolean scopeIsSetAndMatches =