[cfe-dev] Static Analyzer: NullDereference checker report not visible

[Gábor Kozár]

I'm playing around with the NullDereference checker (Dereference.cpp) in an
attempt to understand how it works.

I've discovered a strange phenomenon. Sometimes the checker finds a bug,
calls reportBug(), a BugReport is created and emitted -- but no warning is
raised.
My test code:

struct Foo
{
        int bar;
};

Foo* getFooPtr(bool cond)
{
    return cond ? new Foo : nullptr;
}

int main(int argc, const char** argv)
{
        Foo* fp = getFooPtr(argc % 2 == 1);
        if( ! fp )
        {
                fp->bar = 0; // bug!
        }

        return 0;
}

Interestingly enough, if I replace the getFooPtr definition above with this:

extern Foo* getFooPtr(bool);

Then the report becomes visible.

Note: I'm using Clang 3.3, but I also checked the latest SVN revision, and
there don't seem to be any changes to the DereferenceChecker code.

Is this a bug, or why could this be? Thanks!

Gabor
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