[cfe-dev] Basic source-to-source transformation with Clang

[Manuel Klimek]

On Mon, Jun 25, 2012 at 2:30 PM, Satya Prakash Prasad <
satyaprakash.prasad at gmail.com> wrote:

> Thanks to all for the response.
>
> I was able to make a progress at least remove the C++ errors but one
> issue remains - identifying the include path for C++ header file. I
> now get output as :
>
> fatal error: 'aio.h' file not found
> #include <aio.h>
>
> // Begin function inc returning int
> int inc(int &p)
> {
>        p++;
>         printf("In inc [%d]\n", p);
>        return p;
> }
> // End function inc
> ……………………………………………………
>
> The file aio.h is in /usr/include directory of my system:
> llvm/build/Release+Asserts/examples> ls -l /usr/include/aio.h
> -rw-r--r-- 1 root root 7135 Jul 17  2009 /usr/include/aio.h
>
> My code modifications are:
>
>    LangOptions languageOptions;
>    languageOptions.CPlusPlus= 1;
>     TheCompInst.createFileManager();
>    FileManager &FileMgr = TheCompInst.getFileManager();
>    TheCompInst.createSourceManager(FileMgr);
>     CompilerInvocation* CI = new CompilerInvocation;
>    CI->setLangDefaults(languageOptions, IK_CXX);
>    TheCompInst.setInvocation(CI);
>    DiagnosticsEngine DiagnosticsEngine = TheCompInst.getDiagnostics();
>    HeaderSearch headerSearch(FileMgr, DiagnosticsEngine, languageOptions,
> TI);
>    HeaderSearchOptions headerSearchOptions;
>    headerSearchOptions.AddPath("/usr/include/c++/4.1.2/backward/",
> frontend::Angled, false, false, false, false, false);
>    headerSearchOptions.AddPath("/usr/include/c++/4.1.2/",
> frontend::Angled, false, false, false, false, false);
>    headerSearchOptions.AddPath("/usr/include/c++/", frontend::Angled,
> false, false, false, false, false);
>    headerSearchOptions.AddPath("/usr/include/", frontend::Angled,
> false, false, false, false, false);
>    Preprocessor preprocessor(DiagnosticsEngine, languageOptions, TI ,
> SourceMgr, headerSearch, TheCompInst);
>    TheCompInst.setPreprocessor(&preprocessor);
>
> I am not sure what I need to do now to remove this error? Though I
> have not yet tried libtooling library but since I have explored CLANG
> using Frontend APIs I am proceeding with the same.
>

Yea, getting the include path search logic right & correctly setup is not
trivial. That's exactly what the tooling library takes care of for you :)
If you want to duplicate that logic, you're of course free to, but I would
guess it'll be more time than switching your code to use the tooling
library...

Cheers,
/Manuel


>
> Thanks gain in advance.
>
> Regards,
> Prakash
>
> On Sat, Jun 23, 2012 at 12:05 AM, Manuel Klimek <klimek at google.com> wrote:
> > On Fri, Jun 22, 2012 at 7:55 PM, John McCall <rjmccall at apple.com> wrote:
> >>
> >> On Jun 22, 2012, at 3:06 AM, Satya Prakash Prasad wrote:
> >> > Thanks John for the clarification.
> >> >
> >> > Can you please let me know how to then create clang instance for C++
> >> > input file?
> >>
> >> I suggest looking at some of the example code to see how it initializes
> >> the
> >> CompilerInstance.  clang-interpreter is an example of this.
> >>
> >> Alternatively, you might be happier just running as a clang plugin, in
> >> which case you should look at the PrintFunctionNames example.
> >
> >
> > For source-2-source translation, there are more alternatives with
> different
> > trade-offs to consider:
> > http://clang.llvm.org/docs/Tooling.html
> >
> > Cheers,
> > /Manuel
> >
> >>
> >>
> >> John.
> >>
> >> _______________________________________________
> >> cfe-dev mailing list
> >> cfe-dev at cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> >
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20120625/b90e138c/attachment.html>