[java] 'yield' statement: parser/PSI (IDEA-216410)

GitOrigin-RevId: d00f2c7536bf06f2ab3c8d0aa97e122f4a2f0d30

java/java-psi-api/src/com/intellij/psi/JavaElementVisitor.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2018 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.
+// 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.psi.javadoc.*;
@@ -36,6 +36,10 @@ public abstract class JavaElementVisitor extends PsiElementVisitor {
     visitStatement(statement);
   }
 
+  public void visitYieldStatement(PsiYieldStatement statement) {
+    visitStatement(statement);
+  }
+
   public void visitClass(PsiClass aClass) {
     visitElement(aClass);
   }

java/java-psi-api/src/com/intellij/psi/JavaTokenType.java

@@ -141,4 +141,5 @@ public interface JavaTokenType extends TokenType {
   IElementType WITH_KEYWORD = new IJavaElementType("WITH");
 
   IElementType VAR_KEYWORD = new IJavaElementType("VAR");
+  IElementType YIELD_KEYWORD = new IJavaElementType("YIELD");
 }

java/java-psi-api/src/com/intellij/psi/PsiKeyword.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 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;
 
 /**
@@ -86,4 +72,5 @@ public interface PsiKeyword extends PsiJavaToken {
   String WITH = "with";
 
   String VAR = "var";
+  String YIELD = "yield";
 }

java/java-psi-api/src/com/intellij/psi/PsiYieldStatement.java

@@ -0,0 +1,19 @@
+// 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 org.jetbrains.annotations.Nullable;
+
+/**
+ * Represents a Java {@code yield} statement.
+ */
+public interface PsiYieldStatement extends PsiStatement {
+  /**
+   * Returns the value expression of the statement, if present.
+   */
+  @Nullable PsiExpression getExpression();
+
+  /**
+   * Returns the {@link PsiSwitchExpression switch expression}, out of which the statement transfers control.
+   */
+  @Nullable PsiSwitchExpression findEnclosingExpression();
+}

java/java-psi-impl/src/com/intellij/lang/java/parser/StatementParser.java

@@ -1,10 +1,11 @@
-// Copyright 2000-2018 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.
+// 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.lang.java.parser;
 
 import com.intellij.codeInsight.daemon.JavaErrorMessages;
 import com.intellij.lang.PsiBuilder;
 import com.intellij.lang.WhitespacesBinders;
 import com.intellij.psi.JavaTokenType;
+import com.intellij.psi.PsiKeyword;
 import com.intellij.psi.impl.source.tree.ElementType;
 import com.intellij.psi.impl.source.tree.JavaElementType;
 import com.intellij.psi.tree.IElementType;
@@ -116,6 +117,9 @@ public class StatementParser {
     else if (tokenType == JavaTokenType.BREAK_KEYWORD) {
       return parseBreakStatement(builder);
     }
+    else if (tokenType == JavaTokenType.IDENTIFIER && PsiKeyword.YIELD.equals(builder.getTokenText())) {
+      return parseYieldStatement(builder);
+    }
     else if (tokenType == JavaTokenType.CONTINUE_KEYWORD) {
       return parseContinueStatement(builder);
     }
@@ -472,6 +476,23 @@ public class StatementParser {
     return statement;
   }
 
+  @NotNull
+  private PsiBuilder.Marker parseYieldStatement(PsiBuilder builder) {
+    PsiBuilder.Marker statement = builder.mark();
+    builder.remapCurrentToken(JavaTokenType.YIELD_KEYWORD);
+    builder.advanceLexer();
+
+    if (myParser.getExpressionParser().parse(builder) == null) {
+      error(builder, JavaErrorMessages.message("expected.expression"));
+    }
+    else {
+      semicolon(builder);
+    }
+
+    done(statement, JavaElementType.YIELD_STATEMENT);
+    return statement;
+  }
+
   @NotNull
   private static PsiBuilder.Marker parseContinueStatement(PsiBuilder builder) {
     PsiBuilder.Marker statement = builder.mark();

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/JavaElementType.java

@@ -118,6 +118,7 @@ public interface JavaElementType {
   IElementType SWITCH_LABEL_STATEMENT = new JavaCompositeElementType("SWITCH_LABEL_STATEMENT", PsiSwitchLabelStatementImpl::new);
   IElementType SWITCH_LABELED_RULE = new JavaCompositeElementType("SWITCH_LABELED_RULE", PsiSwitchLabeledRuleStatementImpl::new);
   IElementType BREAK_STATEMENT = new JavaCompositeElementType("BREAK_STATEMENT", PsiBreakStatementImpl::new);
+  IElementType YIELD_STATEMENT = new JavaCompositeElementType("YIELD_STATEMENT", PsiYieldStatementImpl::new);
   IElementType CONTINUE_STATEMENT = new JavaCompositeElementType("CONTINUE_STATEMENT", PsiContinueStatementImpl::new);
   IElementType RETURN_STATEMENT = new JavaCompositeElementType("RETURN_STATEMENT", PsiReturnStatementImpl::new);
   IElementType THROW_STATEMENT = new JavaCompositeElementType("THROW_STATEMENT", PsiThrowStatementImpl::new);

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiYieldStatementImpl.java

@@ -0,0 +1,47 @@
+// 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.impl.source.tree.java;
+
+import com.intellij.psi.*;
+import com.intellij.psi.impl.PsiImplUtil;
+import com.intellij.psi.impl.source.tree.CompositePsiElement;
+import com.intellij.psi.impl.source.tree.ElementType;
+import com.intellij.psi.impl.source.tree.JavaElementType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class PsiYieldStatementImpl extends CompositePsiElement implements PsiYieldStatement {
+  public PsiYieldStatementImpl() {
+    super(JavaElementType.YIELD_STATEMENT);
+  }
+
+  @Override
+  public PsiExpression getExpression() {
+    return (PsiExpression)findPsiChildByType(ElementType.EXPRESSION_BIT_SET);
+  }
+
+  @Nullable
+  @Override
+  public PsiSwitchExpression findEnclosingExpression() {
+    PsiElement element = this, enclosing;
+    while ((enclosing = PsiImplUtil.findEnclosingSwitchOrLoop(element)) != null) {
+      if (enclosing instanceof PsiSwitchExpression) return (PsiSwitchExpression)enclosing;
+      element = enclosing.getParent();
+    }
+    return null;
+  }
+
+  @Override
+  public void accept(@NotNull PsiElementVisitor visitor) {
+    if (visitor instanceof JavaElementVisitor) {
+      ((JavaElementVisitor)visitor).visitYieldStatement(this);
+    }
+    else {
+      visitor.visitElement(this);
+    }
+  }
+
+  @Override
+  public String toString() {
+    return "PsiYieldStatement";
+  }
+}

java/java-tests/testData/psi/parser-partial/statements/Yield.txt

@@ -0,0 +1,9 @@
+PsiJavaFile:Yield.java
+  PsiYieldStatement
+    PsiJavaToken:YIELD('yield')
+    PsiWhiteSpace(' ')
+    PsiReferenceExpression:x
+      PsiReferenceParameterList
+        <empty list>
+      PsiIdentifier:x('x')
+    PsiJavaToken:SEMICOLON(';')

java/java-tests/testData/psi/parser-partial/statements/YieldCall.txt

@@ -0,0 +1,16 @@
+PsiJavaFile:YieldCall.java
+  PsiExpressionStatement
+    PsiMethodCallExpression:foo.yield()
+      PsiReferenceExpression:foo.yield
+        PsiReferenceExpression:foo
+          PsiReferenceParameterList
+            <empty list>
+          PsiIdentifier:foo('foo')
+        PsiJavaToken:DOT('.')
+        PsiReferenceParameterList
+          <empty list>
+        PsiIdentifier:yield('yield')
+      PsiExpressionList
+        PsiJavaToken:LPARENTH('(')
+        PsiJavaToken:RPARENTH(')')
+    PsiJavaToken:SEMICOLON(';')

java/java-tests/testData/psi/parser-partial/statements/YieldIncomplete0.txt

@@ -0,0 +1,6 @@
+PsiJavaFile:YieldIncomplete0.java
+  PsiYieldStatement
+    PsiJavaToken:YIELD('yield')
+    PsiErrorElement:Expression expected
+      <empty list>
+  PsiWhiteSpace(' ')

java/java-tests/testData/psi/parser-partial/statements/YieldIncomplete1.txt

@@ -0,0 +1,10 @@
+PsiJavaFile:YieldIncomplete1.java
+  PsiYieldStatement
+    PsiJavaToken:YIELD('yield')
+    PsiWhiteSpace(' ')
+    PsiReferenceExpression:x
+      PsiReferenceParameterList
+        <empty list>
+      PsiIdentifier:x('x')
+    PsiErrorElement:';' expected
+      <empty list>

java/java-tests/testData/psi/parser-partial/statements/YieldNested.txt

@@ -0,0 +1,28 @@
+PsiJavaFile:YieldNested.java
+  PsiYieldStatement
+    PsiJavaToken:YIELD('yield')
+    PsiWhiteSpace(' ')
+    PsiSwitchExpression: 0
+      PsiKeyword:switch('switch')
+      PsiWhiteSpace(' ')
+      PsiJavaToken:LPARENTH('(')
+      PsiLiteralExpression:0
+        PsiJavaToken:INTEGER_LITERAL('0')
+      PsiJavaToken:RPARENTH(')')
+      PsiWhiteSpace(' ')
+      PsiCodeBlock
+        PsiJavaToken:LBRACE('{')
+        PsiWhiteSpace(' ')
+        PsiSwitchLabelStatement
+          PsiKeyword:default('default')
+          PsiJavaToken:COLON(':')
+        PsiWhiteSpace(' ')
+        PsiYieldStatement
+          PsiJavaToken:YIELD('yield')
+          PsiWhiteSpace(' ')
+          PsiLiteralExpression:42
+            PsiJavaToken:INTEGER_LITERAL('42')
+          PsiJavaToken:SEMICOLON(';')
+        PsiWhiteSpace(' ')
+        PsiJavaToken:RBRACE('}')
+    PsiJavaToken:SEMICOLON(';')

java/java-tests/testSrc/com/intellij/java/parser/partial/StatementParserTest.java

@@ -1,9 +1,10 @@
-// Copyright 2000-2018 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.
+// 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.java.parser.partial;
 
 import com.intellij.java.parser.JavaParsingTestCase;
 import com.intellij.lang.java.parser.JavaParser;
 
+@SuppressWarnings("GraziInspection")
 public class StatementParserTest extends JavaParsingTestCase {
   public StatementParserTest() {
     super("parser-partial/statements");
@@ -28,6 +29,12 @@ public class StatementParserTest extends JavaParsingTestCase {
   public void testBreakIncomplete() { doParserTest("break"); }
   public void testBreakExpr() { doParserTest("break boo();"); }
 
+  public void testYield() { doParserTest("yield x;"); }
+  public void testYieldNested() { doParserTest("yield switch (0) { default: yield 42; };"); }
+  public void testYieldIncomplete0() { doParserTest("yield "); }
+  public void testYieldIncomplete1() { doParserTest("yield x"); }
+  public void testYieldCall() { doParserTest("foo.yield();"); }
+
   public void testContinueNormal0() { doParserTest("continue;"); }
   public void testContinueNormal1() { doParserTest("continue LABEL;"); }