Bug 143770 – GCC warns that JSValue v is used without initialization

• Status: NEW
• Component: New Bugs

[LRN]

../webkitgtk-2.4.8/Source/JavaScriptCore/runtime/JSObject.cpp: In member function 'JSC::ContiguousJSValues JSC::JSObject::genericConvertDoubleToContiguous(JSC::VM&) [with JSC::JSObject::DoubleToContiguousMode mode = (JSC::JSObject::DoubleToContiguousMode)0u; JSC::ContiguousJSValues = JSC::ContiguousData<JSC::WriteBarrier<JSC::Unknown> >]':
../webkitgtk-2.4.8/Source/JavaScriptCore/runtime/JSObject.cpp:822:17: warning: 'v' is used uninitialized in this function [-Wuninitialized]

This shouldn't really happen, as the enumeration only has two values,
but gcc doesn't seem to understand it. Probably because it's a template.
Also, 'v' is an object, so there's an uninitialized object that participates
in a '=' operator, so that could be the cause for concern as well.

[LRN]

Created attachment 250817 [details]
Silence the warning about JSValue 'v' being uninitialized

This shouldn't really happen, as the enumeration only has two values,
but gcc doesn't seem to understand it. Probably because it's a template.
Also, 'v' is an object, so there's an uninitialized object that participates
in a '=' operator, so that could be the cause for concern as well.

Fix this by completely separating two cases at the cost of code duplication.

Otherwise one would get this:
../webkitgtk-2.4.8/Source/JavaScriptCore/runtime/JSObject.cpp: In member function 'JSC::ContiguousJSValues JSC::JSObject::genericConvertDoubleToContiguous(JSC::VM&) [with JSC::JSObject::DoubleToContiguousMode mode = (JSC::JSObject::DoubleToContiguousMode)0u; JSC::ContiguousJSValues = JSC::ContiguousData<JSC::WriteBarrier<JSC::Unknown> >]':
../webkitgtk-2.4.8/Source/JavaScriptCore/runtime/JSObject.cpp:822:17: warning: 'v' is used uninitialized in this function [-Wuninitialized]

[Alexey Proskuryakov]

Comment on attachment 250817 [details]
Silence the warning about JSValue 'v' being uninitialized

R-, because the patch does not apply to trunk. Also, the change to switch indentation is incorrect per WebKit style.

[LRN]

Maybe this could be fixed by backporting whatever code is in the trunk now? Since this patch does not apply, i'm assuming that the code changed since 2.4.x