1543659 - TypedArray broken on 64-bit big endian

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, defect, P5)

Description

[Julien Cristau [:jcristau]]

The JSPropertySpec::ValueWrapper struct contains a union with a pointer and a int32. When writing an int through JS_INT32_PS → INT32VALUE_WRAPPER we actually cast the int32 to a pointer and write to the pointer slot.

Then when we read it back through the int32 member, we end up getting the high-order 32 bits of the pointer, which are 0.

This breaks at least TypedArrays' BYTES_PER_ELEMENT property.

Comment 1

[Julien Cristau [:jcristau]]

Attachment: Bug 1543659 - fix JSPropertySpec::ValueWrapper on 64-bit big-endian platforms

Add some padding to make the union's int32 member correspond to the
low-order bits of the string member. This fixes TypedArray tests on
platforms such as s390x, ppc64 and sparc64.

Comment 2

[Julien Cristau [:jcristau]]

Looks like this code comes from bug 1015798.

Comment 3

[Julien Cristau [:jcristau]]

Bug 1543843 fixes this.