8059371: Code duplication in handling of break and continue
authorattila
Wed, 01 Oct 2014 10:26:53 +0200
changeset 26889 dba314d7a634
parent 26888 2722a9c501a5
child 26890 fa03d7a7d50e
8059371: Code duplication in handling of break and continue Reviewed-by: jlaskey, lagergren
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/CodeGenerator.java
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/LocalVariableTypesCalculator.java
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Lower.java
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/BreakNode.java
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/ContinueNode.java
nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/JumpStatement.java
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/CodeGenerator.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/CodeGenerator.java	Wed Oct 01 10:26:53 2014 +0200
@@ -104,6 +104,7 @@
 import jdk.nashorn.internal.ir.IndexNode;
 import jdk.nashorn.internal.ir.JoinPredecessor;
 import jdk.nashorn.internal.ir.JoinPredecessorExpression;
+import jdk.nashorn.internal.ir.JumpStatement;
 import jdk.nashorn.internal.ir.LabelNode;
 import jdk.nashorn.internal.ir.LexicalContext;
 import jdk.nashorn.internal.ir.LexicalContextNode;
@@ -1204,17 +1205,21 @@
 
     @Override
     public boolean enterBreakNode(final BreakNode breakNode) {
+        return enterJumpStatement(breakNode);
+    }
+
+    private boolean enterJumpStatement(final JumpStatement jump) {
         if(!method.isReachable()) {
             return false;
         }
-        enterStatement(breakNode);
-
-        method.beforeJoinPoint(breakNode);
-        final BreakableNode breakFrom = lc.getBreakable(breakNode.getLabelName());
-        popScopesUntil(breakFrom);
-        final Label breakLabel = breakFrom.getBreakLabel();
-        breakLabel.markAsBreakTarget();
-        method.splitAwareGoto(lc, breakLabel, breakFrom);
+        enterStatement(jump);
+
+        method.beforeJoinPoint(jump);
+        final BreakableNode target = jump.getTarget(lc);
+        popScopesUntil(target);
+        final Label targetLabel = jump.getTargetLabel(target);
+        targetLabel.markAsBreakTarget();
+        method.splitAwareGoto(lc, targetLabel, target);
 
         return false;
     }
@@ -1517,19 +1522,7 @@
 
     @Override
     public boolean enterContinueNode(final ContinueNode continueNode) {
-        if(!method.isReachable()) {
-            return false;
-        }
-        enterStatement(continueNode);
-        method.beforeJoinPoint(continueNode);
-
-        final LoopNode continueTo = lc.getContinueTo(continueNode.getLabelName());
-        popScopesUntil(continueTo);
-        final Label continueLabel = continueTo.getContinueLabel();
-        continueLabel.markAsBreakTarget();
-        method.splitAwareGoto(lc, continueLabel, continueTo);
-
-        return false;
+        return enterJumpStatement(continueNode);
     }
 
     @Override
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/LocalVariableTypesCalculator.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/LocalVariableTypesCalculator.java	Wed Oct 01 10:26:53 2014 +0200
@@ -464,21 +464,20 @@
 
     @Override
     public boolean enterBreakNode(final BreakNode breakNode) {
-        if(!reachable) {
-            return false;
-        }
-
-        final BreakableNode target = lc.getBreakable(breakNode.getLabelName());
-        return splitAwareJumpToLabel(breakNode, target, target.getBreakLabel());
+        return enterJumpStatement(breakNode);
     }
 
     @Override
     public boolean enterContinueNode(final ContinueNode continueNode) {
+        return enterJumpStatement(continueNode);
+    }
+
+    private boolean enterJumpStatement(final JumpStatement jump) {
         if(!reachable) {
             return false;
         }
-        final LoopNode target = lc.getContinueTo(continueNode.getLabelName());
-        return splitAwareJumpToLabel(continueNode, target, target.getContinueLabel());
+        final BreakableNode target = jump.getTarget(lc);
+        return splitAwareJumpToLabel(jump, target, jump.getTargetLabel(target));
     }
 
     private boolean splitAwareJumpToLabel(final JumpStatement jumpStatement, final BreakableNode target, final Label targetLabel) {
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Lower.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Lower.java	Wed Oct 01 10:26:53 2014 +0200
@@ -52,6 +52,7 @@
 import jdk.nashorn.internal.ir.FunctionNode.CompilationState;
 import jdk.nashorn.internal.ir.IdentNode;
 import jdk.nashorn.internal.ir.IfNode;
+import jdk.nashorn.internal.ir.JumpStatement;
 import jdk.nashorn.internal.ir.LabelNode;
 import jdk.nashorn.internal.ir.LexicalContext;
 import jdk.nashorn.internal.ir.LiteralNode;
@@ -382,12 +383,16 @@
 
             @Override
             public Node leaveBreakNode(final BreakNode breakNode) {
-                return copy(breakNode, (Node)Lower.this.lc.getBreakable(breakNode.getLabelName()));
+                return leaveJumpStatement(breakNode);
             }
 
             @Override
             public Node leaveContinueNode(final ContinueNode continueNode) {
-                return copy(continueNode, Lower.this.lc.getContinueTo(continueNode.getLabelName()));
+                return leaveJumpStatement(continueNode);
+            }
+
+            private Node leaveJumpStatement(final JumpStatement jump) {
+                return copy(jump, (Node)jump.getTarget(Lower.this.lc));
             }
 
             @Override
@@ -627,7 +632,7 @@
             @Override
             public Node leaveContinueNode(final ContinueNode node) {
                 // all inner loops have been popped.
-                if (lex.contains(lex.getContinueTo(node.getLabelName()))) {
+                if (lex.contains(node.getTarget(lex))) {
                     escapes.add(node);
                 }
                 return node;
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/BreakNode.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/BreakNode.java	Wed Oct 01 10:26:53 2014 +0200
@@ -25,6 +25,7 @@
 
 package jdk.nashorn.internal.ir;
 
+import jdk.nashorn.internal.codegen.Label;
 import jdk.nashorn.internal.ir.annotations.Immutable;
 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
 
@@ -68,4 +69,14 @@
     String getStatementName() {
         return "break";
     }
+
+    @Override
+    public BreakableNode getTarget(final LexicalContext lc) {
+        return lc.getBreakable(getLabelName());
+    }
+
+    @Override
+    public Label getTargetLabel(final BreakableNode target) {
+        return target.getBreakLabel();
+    }
 }
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/ContinueNode.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/ContinueNode.java	Wed Oct 01 10:26:53 2014 +0200
@@ -25,6 +25,7 @@
 
 package jdk.nashorn.internal.ir;
 
+import jdk.nashorn.internal.codegen.Label;
 import jdk.nashorn.internal.ir.annotations.Immutable;
 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
 
@@ -67,5 +68,16 @@
     String getStatementName() {
         return "continue";
     }
+
+
+    @Override
+    public BreakableNode getTarget(final LexicalContext lc) {
+        return lc.getContinueTo(getLabelName());
+    }
+
+    @Override
+    public Label getTargetLabel(final BreakableNode target) {
+        return ((LoopNode)target).getContinueLabel();
+    }
 }
 
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/JumpStatement.java	Wed Oct 01 10:26:25 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/JumpStatement.java	Wed Oct 01 10:26:53 2014 +0200
@@ -25,6 +25,8 @@
 
 package jdk.nashorn.internal.ir;
 
+import jdk.nashorn.internal.codegen.Label;
+
 /**
  * Common base class for jump statements (e.g. {@code break} and {@code continue}).
  */
@@ -82,6 +84,24 @@
 
     abstract String getStatementName();
 
+    /**
+     * Finds the target for this jump statement in a lexical context.
+     * @param lc the lexical context
+     * @return the target, or null if not found
+     */
+    public abstract BreakableNode getTarget(final LexicalContext lc);
+
+    /**
+     * Returns the label corresponding to this kind of jump statement (either a break or continue label) in the target.
+     * @param target the target. Note that it need not be the target of this jump statement, as the method can retrieve
+     * a label on any passed target as long as the target has a label of the requisite kind. Of course, it is advisable
+     * to invoke the method on a jump statement that targets the breakable.
+     * @return the label of the target corresponding to the kind of jump statement.
+     * @throws ClassCastException if invoked on the kind of breakable node that this jump statement is not prepared to
+     * handle.
+     */
+    public abstract Label getTargetLabel(final BreakableNode target);
+
     @Override
     public JumpStatement setLocalVariableConversion(final LexicalContext lc, final LocalVariableConversion conversion) {
         if(this.conversion == conversion) {