Partial fix for http://code.google.com/p/google-web-toolkit/issues/detail?id=5707
Modify JsInliner to avoid propagating expressions incorrectly.
in EvaluationOrderVisitor, two changes were made. First of all, a clinit() call
is treated as violating order, the same as any other invocation.
Secondly, a JsNameRef that can be affected by side effects (a global, non-param,
non-local) that is visited when there are still expressions that need evaluation
first, is treated as violating order.
This fixes the showcase issue, but is still insufficient. Side-effect inducing
expressions (assignment, post/prefix increment ops) are still not handled. The
exemption of JsNameRefs that are locals is also insufficient, since a side
effect inducing parameter value may be aliased to the same object as this local.
After your review, I may remove it and just ban any non-param reference from
occuring while there are still params to be evaluated.
I tested this and it seems to fix the problem.
Review by: scottb@google.com
git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9362 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/src/com/google/gwt/dev/js/JsInliner.java b/dev/core/src/com/google/gwt/dev/js/JsInliner.java
index 2469762..0c414e6 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsInliner.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsInliner.java
@@ -611,10 +611,35 @@
private boolean maintainsOrder = true;
private final List<JsName> toEvaluate;
private final List<JsName> unevaluated;
+ private final Set<JsName> paramsOrLocals = new HashSet<JsName>();
- public EvaluationOrderVisitor(List<JsName> toEvaluate) {
+ public EvaluationOrderVisitor(List<JsName> toEvaluate, JsFunction callee) {
this.toEvaluate = toEvaluate;
this.unevaluated = new ArrayList<JsName>(toEvaluate);
+ // collect params and locals from callee function
+ new JsVisitor() {
+ @Override
+ public void endVisit(JsParameter x, JsContext<JsParameter> ctx) {
+ paramsOrLocals.add(x.getName());
+ }
+
+ @Override
+ public boolean visit(JsVar x, JsContext<JsVar> ctx) {
+ // record this before visiting initializer
+ paramsOrLocals.add(x.getName());
+ return true;
+ }
+ }.accept(callee);
+ }
+
+ /**
+ * Referencing an array breaks order if there are unevaluated arguments.
+ */
+ @Override
+ public void endVisit(JsArrayAccess x, JsContext<JsExpression> ctx) {
+ if (unevaluated.size() > 0) {
+ maintainsOrder = false;
+ }
}
@Override
@@ -669,12 +694,7 @@
*/
@Override
public void endVisit(JsInvocation x, JsContext<JsExpression> ctx) {
- /*
- * The check for isExecuteOnce() is potentially incorrect here, however
- * the original Java semantics of the clinit would have made the code
- * incorrect anyway.
- */
- if ((isExecuteOnce(x) == null) && unevaluated.size() > 0) {
+ if (unevaluated.size() > 0) {
maintainsOrder = false;
}
}
@@ -710,11 +730,35 @@
return maintainsOrder && unevaluated.size() == 0;
}
+ /**
+ * Check to see if the evaluation of this JsName will break program order assumptions given
+ * the parameters left to be substituted.
+ *
+ * The cases are as follows:
+ * 1) JsName is a function parameter name which has side effects or is affected by side effects
+ * (hereafter called 'volatile'), so it will be in 'toEvaluate'
+ * 2) JsName is a function parameter which is not volatile (not in toEvaluate)
+ * 3) JsName is a reference to a global variable
+ * 4) JsName is a reference to a local variable
+ *
+ * A reference to a global while there are still parameters left to evaluate / substitute
+ * implies an order volation.
+ *
+ * A reference to a volatile parameter is ok if it if is the next parameter in sequence to
+ * be evaluated (beginning of unevaluated list). Else, it is either being evaluated out of
+ * order with respect to other parameters, or it is being evaluated more than once.
+ */
private void checkName(JsName name) {
if (!toEvaluate.contains(name)) {
+ // if the name is a non-local/non-parameter (e.g. global) and there are params left to eval
+ if (!paramsOrLocals.contains(name) && unevaluated.size() > 0) {
+ maintainsOrder = false;
+ }
+ // else this may be a local, or all volatile params have already been evaluated, so it's ok.
return;
}
+ // either this param is being evaled twice, or out of order
if (unevaluated.size() == 0 || !unevaluated.remove(0).equals(name)) {
maintainsOrder = false;
}
@@ -1945,7 +1989,7 @@
* order.
*/
EvaluationOrderVisitor orderVisitor = new EvaluationOrderVisitor(
- requiredOrder);
+ requiredOrder, callee);
orderVisitor.accept(toInline);
if (!orderVisitor.maintainsOrder()) {
return false;
diff --git a/dev/core/test/com/google/gwt/dev/js/JsInlinerTest.java b/dev/core/test/com/google/gwt/dev/js/JsInlinerTest.java
index cb1f37b..108a87d 100644
--- a/dev/core/test/com/google/gwt/dev/js/JsInlinerTest.java
+++ b/dev/core/test/com/google/gwt/dev/js/JsInlinerTest.java
@@ -81,6 +81,94 @@
}
/**
+ * Test that an array reference breaks argument ordering.
+ */
+ public void testOrderingArray() throws Exception {
+ StringBuffer code = new StringBuffer();
+
+ code.append("function clinit() { clinit = null; }");
+
+ // callee references array[0] before evaluating argument
+ code.append("function callee(arg) { var array; return array[0] + arg; }");
+
+ // caller invokes callee with a multi that runs clinit()
+ code.append("function caller() { callee((clinit(),2)); }");
+
+ // bootstrap the program
+ code.append("caller();");
+
+ compare(code.toString(), code.toString());
+ }
+
+ /**
+ * Test that a field reference breaks argument ordering.
+ */
+ public void testOrderingField() throws Exception {
+ StringBuffer code = new StringBuffer();
+
+ code.append("function clinit() { clinit = null; }");
+
+ // callee references field.x before evaluating argument
+ code.append("function callee(arg) { var field; return field.x + arg; }");
+
+ // caller invokes callee with a multi that runs clinit()
+ code.append("function caller() { callee((clinit(),2)); }");
+
+ // bootstrap the program
+ code.append("caller();");
+
+ compare(code.toString(), code.toString());
+ }
+
+ /**
+ * Test that a global variable breaks argument ordering.
+ */
+ public void testOrderingGlobal() throws Exception {
+ StringBuffer code = new StringBuffer();
+ // A global variable x
+ code.append("var x;");
+
+ // clinit() sets up x
+ code.append("function clinit() { x = 1; clinit = null; }");
+
+ // callee references x before evaluating argument
+ code.append("function callee(arg) { alert(x); return arg; }");
+
+ // caller invokes callee with a multi that runs clinit()
+ code.append("function caller() { callee((clinit(),2)); }");
+
+ // bootstrap the program
+ code.append("caller();");
+
+ compare(code.toString(), code.toString());
+ }
+
+ /**
+ * Test that a local variable does not break argument ordering.
+ */
+ public void testOrderingLocal() throws Exception {
+ StringBuffer code = new StringBuffer();
+
+ code.append("function clinit() { clinit = null; }");
+
+ // callee references y before evaluating argument
+ code.append("function callee(arg) { var y; y=2; return arg; }");
+
+ // caller invokes callee with a multi that runs clinit()
+ code.append("function caller() { return callee((clinit(),3)); }");
+
+ // bootstrap the program
+ code.append("caller();");
+
+ StringBuffer expected = new StringBuffer();
+
+ expected.append("function clinit() { clinit = null; }");
+ expected.append("function caller() {var y; return y=2,clinit(),3;}");
+ expected.append("caller();");
+ compare(expected.toString(), code.toString());
+ }
+
+ /**
* Test that a new expression breaks argument ordering.
*/
public void testOrderingNew() throws Exception {
