Closed Bug 458728 Opened 11 years ago Closed 7 years ago

gcc warning: src/nsAttrAndChildArray.cpp:169: warning: comparison is always true due to limited range of data type

Categories

(Firefox Build System :: Source Code Analysis, defect)

x86
All
defect
Not set

Tracking

(Not tracked)

RESOLVED FIXED

People

(Reporter: guninski, Unassigned)

References

(Blocks 1 open bug)

Details

(Whiteboard: [build_warning])

Attachments

(1 file)

+++ This bug was initially created as a clone of Bug #458491 +++
Whiteboard: [build_warning]
Blocks: 458491
No longer depends on: 458491
http://mxr.mozilla.org/mozilla-central/source/content/base/src/nsAttrAndChildArray.cpp#169

167   PRUint32 childCount = ChildCount();
168 
169   NS_ENSURE_TRUE(childCount < ATTRCHILD_ARRAY_MAX_CHILD_COUNT,
170                  NS_ERROR_FAILURE);
Summary: gcc warning: src/nsAttrAndChildArray.cpp:167: warning: comparison is always true due to limited range of data type → gcc warning: src/nsAttrAndChildArray.cpp:169: warning: comparison is always true due to limited range of data type
Blocks: buildwarning
Is this a valid problem?
Maybe today the comparison is unneeded with the current value of ATTRCHILD_ARRAY_MAX_CHILD_COUNT. But if that constant changes, it may be necessary to catch it here.
Comment on attachment 620444 [details] [diff] [review]
Patch

Sorry, I'm not a peer; redirecting to someone who is :-)
Attachment #620444 - Flags: review?(bmo) → review?(bzbarsky)
Why is this warning at all?  childCount is a PRUint32.  ATTRCHILD_ARRAY_MAX_CHILD_COUNT should be 0x3fffff.  There are certainly values of PRUint32 that are bigger than that!

Marco, I assume you reproduced the warning?
Note that back when the bug was filed, a 64-bit build would have warned here.  But that should have been fixed in bug 480655.
(In reply to Boris Zbarsky (:bz) from comment #6)
> Marco, I assume you reproduced the warning?

No, I just assumed it was reproducible. I didn't see the bug was so old.
Status: NEW → RESOLVED
Closed: 7 years ago
Resolution: --- → INVALID
Depends on: 480655
Resolution: INVALID → FIXED
Attachment #620444 - Flags: review?(bzbarsky) → review-
Product: Core → Firefox Build System
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