Bug 162551 – -Wtautological-compare triggered in URLParser::internalValuesConsistent

• Status: RESOLVED
• Resolution: FIXED
• Component: WebCore Misc.

[Michael Catanzaro]

This is wrong:

[3876/6045] Building CXX object Source...s/WebCore.dir/platform/URLParser.cpp.o
../../Source/WebCore/platform/URLParser.cpp: In static member function ‘static bool WebCore::URLParser::internalValuesConsistent(const WebCore::URL&)’:
../../Source/WebCore/platform/URLParser.cpp:2357:26: warning: self-comparison always evaluates to true [-Wtautological-compare]
         && url.m_hostEnd <= url.m_hostEnd
            ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~

[Michael Catanzaro]

Created attachment 289810 [details]
Patch

[Alexey Proskuryakov]

Can a regression test detect this?

Also, can this warning be enabled in normal build?

[Alex Christensen]

Comment on attachment 289810 [details]
Patch

We shouldn't be able to add a regression test for this because both inequalities should always be true.  If either one can be false, there is a major error in the parser.  There are a few such cases right now, but when I'm finished soon there won't be.
We should enable the warning somewhere, if not everywhere.

[Michael Catanzaro]

Comment on attachment 289810 [details]
Patch

With GCC it's enabled by -Wall, which is set in CMake ports by WEBKIT_SET_EXTRA_COMPILER_FLAGS, which *hopefully* is used on all targets. Definitely seems like a good idea to set it in Xcode builds as well, but you'll forgive me if I don't assist with that. ;)

[WebKit Commit Bot]

Comment on attachment 289810 [details]
Patch

Clearing flags on attachment: 289810

Committed r206385: <http://trac.webkit.org/changeset/206385>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.