[java] value breaks: PSI improvements (IDEA-CR-40172)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java

@@ -783,17 +783,19 @@ public class HighlightUtil extends HighlightUtilBase {
   @Nullable
   static HighlightInfo checkValueBreakExpression(@NotNull PsiBreakStatement statement, @Nullable PsiExpression expression) {
     PsiElement enclosing = PsiImplUtil.findEnclosingSwitchOrLoop(statement);
+    boolean plainRef = PsiImplUtil.isPlainReference(expression);
+
     if (enclosing instanceof PsiSwitchExpression) {
       if (expression == null) {
         String message = JavaErrorMessages.message("value.break.missing");
         return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(statement).descriptionAndTooltip(message).create();
       }
-      if (PsiTreeUtil.isAncestor(statement.findExitedElement(), enclosing, true)) {
+      if (plainRef && PsiTreeUtil.isAncestor(((PsiReferenceExpression)expression).resolve(), enclosing, true)) {
         String message = JavaErrorMessages.message("break.outside.switch.expr");
         return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(statement).descriptionAndTooltip(message).create();
       }
     }
-    else if (expression != null && (!PsiImplUtil.isPlainReference(expression) || ((PsiReferenceExpression)expression).resolve() instanceof PsiVariable)) {
+    else if (expression != null && !plainRef) {
       String message = JavaErrorMessages.message("value.break.unexpected");
       return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(statement).descriptionAndTooltip(message).create();
     }
@@ -814,6 +816,7 @@ public class HighlightUtil extends HighlightUtilBase {
   @Nullable
   static HighlightInfo checkContinueTarget(@NotNull PsiContinueStatement statement, @NotNull PsiIdentifier label, @NotNull LanguageLevel level) {
     PsiStatement continuedStatement = statement.findContinuedStatement();
+
     if (continuedStatement == null) {
       String message = JavaErrorMessages.message("unresolved.label", label.getText());
       return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(label).descriptionAndTooltip(message).create();
@@ -822,6 +825,7 @@ public class HighlightUtil extends HighlightUtilBase {
       String message = JavaErrorMessages.message("not.loop.label", label.getText());
       return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(statement).descriptionAndTooltip(message).create();
     }
+
     if (level.isAtLeast(LanguageLevel.JDK_12_PREVIEW)) {
       PsiElement enclosing = PsiImplUtil.findEnclosingSwitchOrLoop(statement);
       if (enclosing instanceof PsiSwitchExpression && PsiTreeUtil.isAncestor(continuedStatement, enclosing, true)) {

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

@@ -1,6 +1,7 @@
 // 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.
 package com.intellij.psi;
 
+import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -8,14 +9,21 @@ import org.jetbrains.annotations.Nullable;
  */
 public interface PsiBreakStatement extends PsiStatement {
   /**
-   * Returns the label identifier iff it is present and the statement is not inside a switch expression, {@code null} otherwise.
-   *
-   * @see #getExpression()
+   * Returns the label expression iff it is present, is an unqualified reference, and the statement is not inside a switch expression,
+   * {@code null} otherwise.
    */
-  @Nullable PsiIdentifier getLabelIdentifier();
+  @Nullable PsiReferenceExpression getLabelExpression();
 
   /**
-   * Returns the label/value expression, or {@code null} if the statement is empty.
+   * Returns the value expression iff it is present and the statement is inside a switch expression, {@code null} otherwise.
+   */
+  @Nullable PsiExpression getValueExpression();
+
+  /**
+   * Returns the label or value expression, or {@code null} if the statement is empty.
+   *
+   * @see #getLabelExpression()
+   * @see #getValueExpression()
    */
   @Nullable PsiExpression getExpression();
 
@@ -25,7 +33,15 @@ public interface PsiBreakStatement extends PsiStatement {
    */
   @Nullable PsiElement findExitedElement();
 
-  /** @deprecated doesn't support "switch" expressions; use {@link #findExitedElement()} instead */
+  /** @deprecated doesn't support switch expressions; use {@link #getLabelExpression()}} instead */
+  @Deprecated
+  @SuppressWarnings("DeprecatedIsStillUsed")
+  default PsiIdentifier getLabelIdentifier() {
+    PsiReferenceExpression expression = getLabelExpression();
+    return expression != null ? PsiTreeUtil.getChildOfType(expression, PsiIdentifier.class) : null;
+  }
+
+  /** @deprecated doesn't support switch expressions; use {@link #findExitedElement()} instead */
   @Deprecated
   @SuppressWarnings("DeprecatedIsStillUsed")
   default PsiStatement findExitedStatement() {

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

@@ -8,7 +8,6 @@ import com.intellij.psi.impl.PsiImplUtil;
 import com.intellij.psi.impl.source.tree.*;
 import com.intellij.psi.tree.ChildRoleBase;
 import com.intellij.psi.tree.IElementType;
-import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.NotNull;
 
 public class PsiBreakStatementImpl extends CompositePsiElement implements PsiBreakStatement {
@@ -19,9 +18,17 @@ public class PsiBreakStatementImpl extends CompositePsiElement implements PsiBre
   }
 
   @Override
-  public PsiIdentifier getLabelIdentifier() {
-    PsiIdentifier labelId = labelId();
-    return labelId != null && !(findExitedElement() instanceof PsiSwitchExpression) ? labelId : null;
+  public PsiReferenceExpression getLabelExpression() {
+    PsiExpression expression = getExpression();
+    boolean isLabel = PsiImplUtil.isPlainReference(expression) && !(PsiImplUtil.findEnclosingSwitchOrLoop(this) instanceof PsiSwitchExpression);
+    return isLabel ? (PsiReferenceExpression)expression : null;
+  }
+
+  @Override
+  public PsiExpression getValueExpression() {
+    PsiExpression expression = getExpression();
+    boolean isValue = expression != null && PsiImplUtil.findEnclosingSwitchOrLoop(this) instanceof PsiSwitchExpression;
+    return isValue ? expression : null;
   }
 
   @Override
@@ -31,29 +38,21 @@ public class PsiBreakStatementImpl extends CompositePsiElement implements PsiBre
 
   @Override
   public PsiElement findExitedElement() {
-    PsiIdentifier label = labelId();
-    if (label == null) {
-      return PsiImplUtil.findEnclosingSwitchOrLoop(this);
+    PsiElement enclosing = PsiImplUtil.findEnclosingSwitchOrLoop(this);
+    PsiExpression expression = getExpression();
+
+    if (enclosing == null || enclosing instanceof PsiSwitchExpression || !PsiImplUtil.isPlainReference(expression)) {
+      return enclosing;
     }
 
-    PsiLabeledStatement labeled = PsiImplUtil.findEnclosingLabeledStatement(this, label.getText());
+    PsiLabeledStatement labeled = PsiImplUtil.findEnclosingLabeledStatement(enclosing, expression.getText());
     if (labeled != null) {
       return labeled.getStatement();
     }
 
-    PsiElement enclosing = PsiImplUtil.findEnclosingSwitchOrLoop(this);
-    if (enclosing instanceof PsiSwitchExpression) {
-      return enclosing;
-    }
-
     return null;
   }
 
-  private PsiIdentifier labelId() {
-    PsiExpression expr = getExpression();
-    return PsiImplUtil.isPlainReference(expr) ? PsiTreeUtil.getChildOfType(expr, PsiIdentifier.class) : null;
-  }
-
   @Override
   public ASTNode findChildByRole(int role) {
     LOG.assertTrue(ChildRole.isUnique(role));