[cfe-dev] Multiple root nodes for CallGraph?

Anna Zaks ganna at apple.com
Sat Oct 1 00:13:50 PDT 2011


Hi Arjun,

Currently, the clang static analyzer only performs intra-procedural analysis. I don't think that any other checkers in the analyzer use CallGraph, so you might need a bit of extra plumbing to construct one.

Also, I am not sure if the checker you are working on is going to be different from the compiler warning:

$ clang -Wall ~/tmp/example.c 
/Users/zaks/tmp/example.c:5:12: warning: unused function 'xxx' [-Wunused-function]
static int foo() {return 3;}

Cheers,
Anna.
On Sep 30, 2011, at 10:36 PM, Arjun Singri wrote:

> Hi,
> 
> Thank you for replying. I will keep that in mind when writing the checker. 
> 
> To use the CallGraph class I need to supply it an object of type "Program". The only way I can get a Program object is through the Indexer object which itself is obtained from AnalysisManager. But when the AnalysisManager object is constructed in Frontend/AnalysisConsumer.cpp:148, a value of zero is passed for the Indexer making the Indexer NULL. Why is this? Can I get a reference to the Program object any other way?
> 
> Thanks,
> Arjun
> 
> On Fri, Sep 30, 2011 at 2:09 PM, Anna Zaks <ganna at apple.com> wrote:
> Hi Arjun,
> 
> scan-build is a script that hijacks the build system to call the static analyzer. Currently, the analyzer can only reason about one translation unit at a time.
> 
> So there is no reason to have multiple roots to represent different main functions. In addition, your checker would/should only be applicable to functions with internal linkage.
> 
> Cheers,
> Anna.
> 
> On Sep 30, 2011, at 12:58 PM, Arjun Singri wrote:
> 
> > Hi,
> >
> > I am currently trying to implement a checker that detects unused methods. I am making use of the CallGraph class for this. Every time CallGraph detects the "main" function, it designates it as the root node. Considering that scan-build accepts multiple files each having a main function, does it make sense to modify CallGraph to have mutlple root nodes?
> >
> > Thanks,
> > Arjun
> > _______________________________________________
> > cfe-dev mailing list
> > cfe-dev at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> 
> 

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