Changeset 34250 in webkit for trunk/JavaScriptCore/kjs/nodes.cpp

Timestamp:

May 29, 2008, 10:45:16 PM (17 years ago)

Author:

[email protected]

Message:

JavaScriptCore:

2008-05-29 Maciej Stachowiak <​[email protected]>

Reviewed by Oliver.

• fixed <rdar://problem/5972943> REGRESSION(r33979): Flash clips do not play on cnn.com

Finally blocks could clobber registers that had to remain live
until they returned. This patch takes a conservative approach and
makes sure that finally blocks do not reuse any registers that
were previously allocated for the function. In the future this
could probably be tightened up to be less profligate with the
register allocation.

• VM/CodeGenerator.cpp: (KJS::CodeGenerator::highestUsedRegister):
• VM/CodeGenerator.h:
• kjs/nodes.cpp: (KJS::TryNode::emitCode):

LayoutTests:

2008-05-29 Maciej Stachowiak <​[email protected]>

Reviewed by Oliver. Test by Geoff Garen.

• fixed <rdar://problem/5972943> REGRESSION(r33979): Flash clips do not play on cnn.com

• fast/js/finally-codegen-failure-expected.txt: Added.
• fast/js/finally-codegen-failure.html: Added.

File:

• trunk/JavaScriptCore/kjs/nodes.cpp (modified) (1 diff)

trunk/JavaScriptCore/kjs/nodes.cpp

@@ -5746 +5746 @@
     if (m_finallyBlock) {
         generator.popFinallyContext();
+        // there may be important registers live at the time we jump
+        // to a finally block (such as for a return or throw) so we
+        // ref the highest register ever used as a conservative
+        // approach to not clobbering anything important
+        RefPtr<RegisterID> highestUsedRegister = generator.highestUsedRegister();
         RefPtr<LabelID> finallyEndLabel = generator.newLabel();
         generator.emitJumpSubroutine(finallyReturnAddr.get(), finallyStart.get());