[llvm-commits] [llvm] r160170 - /llvm/trunk/include/llvm/Support/CommandLine.h

[Alexander Kornienko]

On Fri, Jul 13, 2012 at 3:06 PM, Duncan Sands <baldrick at free.fr> wrote:

> Hi Alexander,
> > Initializers for some fields were missing in Option::Option
>
> did it matter?  If so, please add a testcase.  If not, why this change?
>
This did matter. It caused random crashes in case cl::opt was a member of
non-POD class. And I always considered it obvious that uninitialized data
is bad. Don't you think so?
The change which lead me to discovery of this bug is here:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20120716/060757.html,
diff here:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/attachments/20120716/6f1649d3/attachment-0001.obj

As for a test case, I'm not sure I can come up with a test case which
relies on uninitialized data. If you can suggest something, I will
certainly implement one.


> Ciao, Duncan.
>
> >
> > Modified:
> >      llvm/trunk/include/llvm/Support/CommandLine.h
> >
> > Modified: llvm/trunk/include/llvm/Support/CommandLine.h
> > URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/CommandLine.h?rev=160170&r1=160169&r2=160170&view=diff
> >
> ==============================================================================
> > --- llvm/trunk/include/llvm/Support/CommandLine.h (original)
> > +++ llvm/trunk/include/llvm/Support/CommandLine.h Fri Jul 13 07:55:23
> 2012
> > @@ -217,11 +217,11 @@
> >     void setMiscFlag(enum MiscFlags M) { Misc |= M; }
> >     void setPosition(unsigned pos) { Position = pos; }
> >   protected:
> > -  explicit Option(enum NumOccurrencesFlag OccurrencesFlag,
> > +  explicit Option(enum NumOccurrencesFlag OccurrencesFlag,
> >                     enum OptionHidden Hidden)
> > -    : NumOccurrences(0), Occurrences(OccurrencesFlag),
> HiddenFlag(Hidden),
> > -      Formatting(NormalFormatting), Position(0),
> > -      AdditionalVals(0), NextRegistered(0),
> > +    : NumOccurrences(0), Occurrences(OccurrencesFlag), Value(0),
> > +      HiddenFlag(Hidden), Formatting(NormalFormatting), Misc(0),
> > +      Position(0), AdditionalVals(0), NextRegistered(0),
> >         ArgStr(""), HelpStr(""), ValueStr("") {
> >     }
> >
> >
> >
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> > llvm-commits at cs.uiuc.edu
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> >
>

-- 
Regards,
Alexander
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