Added comments, small bugfix post the long emulation merge in response to review comments.
Suggested by: spoon
Review by: spoon
git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@2173 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java b/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
index c14e418..c3ce727 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
@@ -82,7 +82,17 @@
private JClassType currentClass;
/**
- * Expressions whose result does not matter.
+ * Expressions whose result does not matter. A parent node should add any
+ * children whose result does not matter to this set during the parent's
+ * <code>visit()</code> method. It should then remove those children
+ * during its own <code>endVisit()</code>.
+ *
+ * TODO: there's a latent bug here: some immutable nodes (such as literals)
+ * can be multiply referenced in the AST. In theory, one reference to that
+ * node could be put into this set while another reference actually contains
+ * a result that is needed. In practice this is okay at the moment since the
+ * existing uses of <code>ignoringExpressionOutput</code> are with mutable
+ * nodes.
*/
private Set<JExpression> ignoringExpressionOutput = new HashSet<JExpression>();
@@ -378,6 +388,7 @@
public void endVisit(JMultiExpression x, Context ctx) {
List<JExpression> exprs = x.exprs;
if (exprs.size() > 1) {
+ // Remove the non-final children we previously added.
List<JExpression> nonFinalChildren = exprs.subList(0, exprs.size() - 1);
ignoringExpressionOutput.removeAll(nonFinalChildren);
}
@@ -425,7 +436,7 @@
if (x.getOp().isModifying()) {
lvalues.remove(x.getArg());
}
- if (x == ignoringExpressionOutput) {
+ if (ignoringExpressionOutput.contains(x)) {
JPrefixOperation newOp = new JPrefixOperation(program,
x.getSourceInfo(), x.getOp(), x.getArg());
ctx.replaceMe(newOp);
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/LongEmulationNormalizer.java b/dev/core/src/com/google/gwt/dev/jjs/impl/LongEmulationNormalizer.java
index bdc3eb8..0127090 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/LongEmulationNormalizer.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/LongEmulationNormalizer.java
@@ -149,7 +149,7 @@
case AND:
case OR:
throw new InternalCompilerException(
- "AND and OR sould not have long operands");
+ "AND and OR should not have long operands");
case ASG:
// Nothing to do.
@@ -183,7 +183,7 @@
return "neg";
case NOT:
throw new InternalCompilerException(
- "NOT sould not have a long operand");
+ "NOT should not have a long operand");
case BIT_NOT:
return "not";
default:
