--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/TryNode.java Wed Jul 05 20:16:23 2017 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/TryNode.java Wed Jan 28 17:58:08 2015 +0100
@@ -27,7 +27,9 @@
import java.util.ArrayList;
import java.util.Collections;
+import java.util.HashSet;
import java.util.List;
+import java.util.Set;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
@@ -35,7 +37,7 @@
* IR representation of a TRY statement.
*/
@Immutable
-public final class TryNode extends Statement implements JoinPredecessor {
+public final class TryNode extends LexicalContextStatement implements JoinPredecessor {
private static final long serialVersionUID = 1L;
/** Try statements. */
@@ -47,12 +49,24 @@
/** Finally clause. */
private final Block finallyBody;
+ /**
+ * List of inlined finally blocks. The structure of every inlined finally is:
+ * Block(LabelNode(label, Block(finally-statements, (JumpStatement|ReturnNode)?))).
+ * That is, the block has a single LabelNode statement with the label and a block containing the
+ * statements of the inlined finally block with the jump or return statement appended (if the finally
+ * block was not terminal; the original jump/return is simply ignored if the finally block itself
+ * terminates). The reason for this somewhat strange arrangement is that we didn't want to create a
+ * separate class for the (label, BlockStatement pair) but rather reused the already available LabelNode.
+ * However, if we simply used List<LabelNode> without wrapping the label nodes in an additional Block,
+ * that would've thrown off visitors relying on BlockLexicalContext -- same reason why we never use
+ * Statement as the type of bodies of e.g. IfNode, WhileNode etc. but rather blockify them even when they're
+ * single statements.
+ */
+ private final List<Block> inlinedFinallies;
+
/** Exception symbol. */
private Symbol exception;
- /** Catchall exception for finally expansion, where applicable */
- private Symbol finallyCatchAll;
-
private final LocalVariableConversion conversion;
/**
@@ -71,21 +85,23 @@
this.catchBlocks = catchBlocks;
this.finallyBody = finallyBody;
this.conversion = null;
+ this.inlinedFinallies = Collections.emptyList();
}
- private TryNode(final TryNode tryNode, final Block body, final List<Block> catchBlocks, final Block finallyBody, final LocalVariableConversion conversion) {
+ private TryNode(final TryNode tryNode, final Block body, final List<Block> catchBlocks, final Block finallyBody, final LocalVariableConversion conversion, final List<Block> inlinedFinallies) {
super(tryNode);
this.body = body;
this.catchBlocks = catchBlocks;
this.finallyBody = finallyBody;
this.conversion = conversion;
+ this.inlinedFinallies = inlinedFinallies;
this.exception = tryNode.exception;
}
@Override
public Node ensureUniqueLabels(final LexicalContext lc) {
//try nodes are never in lex context
- return new TryNode(this, body, catchBlocks, finallyBody, conversion);
+ return new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies);
}
@Override
@@ -106,16 +122,16 @@
* @param visitor IR navigating visitor.
*/
@Override
- public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
+ public Node accept(final LexicalContext lc, NodeVisitor<? extends LexicalContext> visitor) {
if (visitor.enterTryNode(this)) {
// Need to do finallybody first for termination analysis. TODO still necessary?
final Block newFinallyBody = finallyBody == null ? null : (Block)finallyBody.accept(visitor);
final Block newBody = (Block)body.accept(visitor);
return visitor.leaveTryNode(
- setBody(newBody).
- setFinallyBody(newFinallyBody).
- setCatchBlocks(Node.accept(visitor, catchBlocks)).
- setFinallyCatchAll(finallyCatchAll));
+ setBody(lc, newBody).
+ setFinallyBody(lc, newFinallyBody).
+ setCatchBlocks(lc, Node.accept(visitor, catchBlocks)).
+ setInlinedFinallies(lc, Node.accept(visitor, inlinedFinallies)));
}
return this;
@@ -136,14 +152,15 @@
/**
* Reset the body of this try block
+ * @param lc current lexical context
* @param body new body
* @return new TryNode or same if unchanged
*/
- public TryNode setBody(final Block body) {
+ public TryNode setBody(final LexicalContext lc, final Block body) {
if (this.body == body) {
return this;
}
- return new TryNode(this, body, catchBlocks, finallyBody, conversion);
+ return Node.replaceInLexicalContext(lc, this, new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies));
}
/**
@@ -172,14 +189,15 @@
/**
* Set the catch blocks of this try
+ * @param lc current lexical context
* @param catchBlocks list of catch blocks
* @return new TryNode or same if unchanged
*/
- public TryNode setCatchBlocks(final List<Block> catchBlocks) {
+ public TryNode setCatchBlocks(final LexicalContext lc, final List<Block> catchBlocks) {
if (this.catchBlocks == catchBlocks) {
return this;
}
- return new TryNode(this, body, catchBlocks, finallyBody, conversion);
+ return Node.replaceInLexicalContext(lc, this, new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies));
}
/**
@@ -200,27 +218,6 @@
}
/**
- * Get the catch all symbol for this try block
- * @return catch all symbol
- */
- public Symbol getFinallyCatchAll() {
- return this.finallyCatchAll;
- }
-
- /**
- * If a finally block exists, the synthetic catchall needs another symbol to
- * store its throwable
- * @param finallyCatchAll a symbol for the finally catch all exception
- * @return new TryNode or same if unchanged
- *
- * TODO can this still be stateful?
- */
- public TryNode setFinallyCatchAll(final Symbol finallyCatchAll) {
- this.finallyCatchAll = finallyCatchAll;
- return this;
- }
-
- /**
* Get the body of the finally clause for this try
* @return finally body, or null if no finally
*/
@@ -229,15 +226,87 @@
}
/**
+ * Get the inlined finally block with the given label name. This returns the actual finally block in the
+ * {@link LabelNode}, not the outer wrapper block for the {@link LabelNode}.
+ * @param labelName the name of the inlined finally's label
+ * @return the requested finally block, or null if no finally block's label matches the name.
+ */
+ public Block getInlinedFinally(final String labelName) {
+ for(final Block inlinedFinally: inlinedFinallies) {
+ final LabelNode labelNode = getInlinedFinallyLabelNode(inlinedFinally);
+ if (labelNode.getLabelName().equals(labelName)) {
+ return labelNode.getBody();
+ }
+ }
+ return null;
+ }
+
+ private static LabelNode getInlinedFinallyLabelNode(final Block inlinedFinally) {
+ return (LabelNode)inlinedFinally.getStatements().get(0);
+ }
+
+ /**
+ * Given an outer wrapper block for the {@link LabelNode} as returned by {@link #getInlinedFinallies()},
+ * returns its actual inlined finally block.
+ * @param inlinedFinally the outer block for inlined finally, as returned as an element of
+ * {@link #getInlinedFinallies()}.
+ * @return the block contained in the {@link LabelNode} contained in the passed block.
+ */
+ public static Block getLabelledInlinedFinallyBlock(final Block inlinedFinally) {
+ return getInlinedFinallyLabelNode(inlinedFinally).getBody();
+ }
+
+ /**
+ * Returns a list of inlined finally blocks. Note that this returns a list of {@link Block}s such that each one of
+ * them has a single {@link LabelNode}, which in turn contains the label name for the finally block and the
+ * actual finally block. To safely extract the actual finally block, use
+ * {@link #getLabelledInlinedFinallyBlock(Block)}.
+ * @return a list of inlined finally blocks.
+ */
+ public List<Block> getInlinedFinallies() {
+ return Collections.unmodifiableList(inlinedFinallies);
+ }
+
+ /**
* Set the finally body of this try
+ * @param lc current lexical context
* @param finallyBody new finally body
* @return new TryNode or same if unchanged
*/
- public TryNode setFinallyBody(final Block finallyBody) {
+ public TryNode setFinallyBody(final LexicalContext lc, final Block finallyBody) {
if (this.finallyBody == finallyBody) {
return this;
}
- return new TryNode(this, body, catchBlocks, finallyBody, conversion);
+ return Node.replaceInLexicalContext(lc, this, new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies));
+ }
+
+ /**
+ * Set the inlined finally blocks of this try. Each element should be a block with a single statement that is a
+ * {@link LabelNode} with a unique label, and the block within the label node should contain the actual inlined
+ * finally block.
+ * @param lc current lexical context
+ * @param inlinedFinallies list of inlined finally blocks
+ * @return new TryNode or same if unchanged
+ */
+ public TryNode setInlinedFinallies(final LexicalContext lc, final List<Block> inlinedFinallies) {
+ if (this.inlinedFinallies == inlinedFinallies) {
+ return this;
+ }
+ assert checkInlinedFinallies(inlinedFinallies);
+ return Node.replaceInLexicalContext(lc, this, new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies));
+ }
+
+ private static boolean checkInlinedFinallies(final List<Block> inlinedFinallies) {
+ if (!inlinedFinallies.isEmpty()) {
+ final Set<String> labels = new HashSet<>();
+ for (final Block inlinedFinally : inlinedFinallies) {
+ final List<Statement> stmts = inlinedFinally.getStatements();
+ assert stmts.size() == 1;
+ final LabelNode ln = getInlinedFinallyLabelNode(inlinedFinally);
+ assert labels.add(ln.getLabelName()); // unique label
+ }
+ }
+ return true;
}
@Override
@@ -245,7 +314,7 @@
if(this.conversion == conversion) {
return this;
}
- return new TryNode(this, body, catchBlocks, finallyBody, conversion);
+ return new TryNode(this, body, catchBlocks, finallyBody, conversion, inlinedFinallies);
}
@Override