[platform] extend PsiReference from SymbolReference (IDEA-190162)

platform/core-api/src/com/intellij/model/SymbolService.java

@@ -0,0 +1,36 @@
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.model;
+
+import com.intellij.model.psi.PsiElementSymbol;
+import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.ApiStatus.Experimental;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+
+@Experimental
+public interface SymbolService {
+
+  @Contract(pure = true)
+  @NotNull
+  static Symbol adaptPsiElement(@NotNull PsiElement element) {
+    if (element instanceof Symbol) {
+      return (Symbol)element;
+    }
+    else {
+      return new PsiElementSymbol(element);
+    }
+  }
+
+  @Contract(pure = true)
+  @NotNull
+  static SymbolResolveResult resolveResult(@NotNull PsiElement element) {
+    Symbol symbol = adaptPsiElement(element);
+    return new SymbolResolveResult() {
+      @NotNull
+      @Override
+      public Symbol getTarget() {
+        return symbol;
+      }
+    };
+  }
+}

platform/core-api/src/com/intellij/model/psi/PsiElementSymbol.java

@@ -0,0 +1,25 @@
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.model.psi;
+
+import com.intellij.model.Symbol;
+import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.ApiStatus.Experimental;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+
+@Experimental
+public final class PsiElementSymbol implements Symbol {
+
+  private final @NotNull PsiElement myElement;
+
+  @Contract(pure = true)
+  public PsiElementSymbol(@NotNull PsiElement element) {
+    myElement = element;
+  }
+
+  @Contract(pure = true)
+  @NotNull
+  public PsiElement getElement() {
+    return myElement;
+  }
+}

platform/core-api/src/com/intellij/psi/PsiPolyVariantReference.java

@@ -1,22 +1,12 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi;
 
+import com.intellij.model.SymbolResolveResult;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Collection;
+
 /**
  * Inherit this interface if you want the reference to resolve to more than one element,
  * or if you want to provide resolve result(s) for a superset of valid resolve cases.
@@ -36,5 +26,13 @@ public interface PsiPolyVariantReference extends PsiReference {
    *
    * @return the array of results for resolving the reference.
    */
-  @NotNull ResolveResult[] multiResolve(boolean incompleteCode);
-}
+  @NotNull
+  ResolveResult[] multiResolve(boolean incompleteCode);
+
+  @NotNull
+  @Override
+  default Collection<? extends SymbolResolveResult> resolveReference() {
+    ResolveResult[] results = multiResolve(false);
+    return ContainerUtil.filter(results, it -> it.getElement() != null);
+  }
+}

platform/core-api/src/com/intellij/psi/PsiReference.java

@@ -1,20 +1,9 @@
-/*
- * Copyright 2000-2018 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi;
 
+import com.intellij.model.SymbolReference;
+import com.intellij.model.SymbolResolveResult;
+import com.intellij.model.SymbolService;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.util.ArrayFactory;
 import com.intellij.util.ArrayUtil;
@@ -22,6 +11,9 @@ import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Collection;
+import java.util.Collections;
+
 /**
  * A reference to a PSI element. For example, the variable name used in an expression.
  * The "Go to Declaration" action can be used to go from a reference to the element it references.
@@ -35,7 +27,8 @@ import org.jetbrains.annotations.Nullable;
  * @see PsiReferenceBase
  * @see PsiReferenceContributor
  */
-public interface PsiReference {
+public interface PsiReference extends SymbolReference {
+
   PsiReference[] EMPTY_ARRAY = new PsiReference[0];
 
   ArrayFactory<PsiReference> ARRAY_FACTORY = count -> count == 0 ? EMPTY_ARRAY : new PsiReference[count];
@@ -138,4 +131,11 @@ public interface PsiReference {
    * @return true if the reference is soft, false otherwise.
    */
   boolean isSoft();
-}
+
+  @NotNull
+  @Override
+  default Collection<? extends SymbolResolveResult> resolveReference() {
+    PsiElement resolved = resolve();
+    return resolved == null ? Collections.emptyList() : Collections.singletonList(SymbolService.resolveResult(resolved));
+  }
+}

platform/core-api/src/com/intellij/psi/ResolveResult.java

@@ -1,28 +1,20 @@
-/*
- * Copyright 2000-2009 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi;
 
+import com.intellij.model.Symbol;
+import com.intellij.model.SymbolResolveResult;
+import com.intellij.model.SymbolService;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
+
 /**
  * Represents the result of resolving a {@link com.intellij.psi.PsiPolyVariantReference}.
  *
  * @see com.intellij.psi.PsiElementResolveResult
  */
-public interface ResolveResult {
+public interface ResolveResult extends SymbolResolveResult {
   /**
    * The empty array of PSI resolve results which can be reused to avoid unnecessary allocations.
    */
@@ -42,4 +34,11 @@ public interface ResolveResult {
    * @return true if the resolve encountered no problems
    */
   boolean isValidResult();
+
+  @NotNull
+  @Override
+  default Symbol getTarget() {
+    PsiElement element = Objects.requireNonNull(getElement(), "Don't access this property on empty results");
+    return SymbolService.adaptPsiElement(element);
+  }
 }

xml/dom-openapi/src/com/intellij/util/xml/converters/DelimitedListConverter.java

@@ -194,7 +194,7 @@ public abstract class DelimitedListConverter<T> extends ResolvingConverter<List<
         return getElement();
       }
       final String value = getValue();
-      return resolveReference(convertString(value, myContext), myContext);
+      return DelimitedListConverter.this.resolveReference(convertString(value, myContext), myContext);
     }
 
     @Override