742788 - js/src/jsinterp.cpp:954:31: warning: comparison of unsigned expression >= 0 is always true

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Daniel Holbert [:dholbert]]

Filing bug on these build warnings:
{
js/src/jsinterp.cpp: In function ‘void LeaveWith(JSContext*)’:
js/src/jsinterp.cpp:954:31: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
js/src/jsopcode.cpp: In member function ‘char& js::Sprinter::operator[](size_t)’:
js/src/jsopcode.cpp:778:14: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
}

In both cases, we're just asserting that a value is nonnegative, and in both cases the value is unsigned so the assertion will trivially always pass.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: fix

In this patch's first chunk, the stackDepth method on WithObject returns uint32, as shown here:
 http://mxr.mozilla.org/mozilla-central/source/js/src/vm/ScopeObject.h#188
(the method is inherited from NestedScopeObject)
So that's unsigned.

And the second chunk directly deals with a size_t variable, which is unsigned by definition.

Comment 2

[Daniel Holbert [:dholbert]]

FWIW, it looks like patch's first chunk (and the stackDepth() method that it calls) was added in Bug 713311:
 http://hg.mozilla.org/mozilla-central/rev/f0d76403ae9c#l25.176
and the second chunk (in jsopcode.cpp) was added in Bug 688891:
 http://hg.mozilla.org/mozilla-central/diff/24dac171a324/js/src/jsopcode.cpp#l1.162

Comment 3

[Luke Wagner [:luke]]

Comment on attachment 612601 [details] [diff] [review]
fix

lol.  To wit, I have the LeaveWith case nixed in a patch in my queue :)

Comment 4

[Daniel Holbert [:dholbert]]

(In reply to Luke Wagner [:luke] from comment #3)
> lol.  To wit, I have the LeaveWith case nixed in a patch in my queue :)

Great minds think alike! :)

Comment 5

[Daniel Holbert [:dholbert]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/b1db4217e068

Comment 6

[Matt Brubeck (:mbrubeck)]

https://hg.mozilla.org/mozilla-central/rev/b1db4217e068