[PATCH, RFC] Fix PR16454

[Hal Finkel]

----- Original Message -----
> http://llvm.org/bugs/show_bug.cgi?id=16454 demonstrates that
> altivec.h
> is being included along paths where it doesn't make much sense to do
> so.
> This file is auto-included when compiling with -faltivec.  What I'm
> proposing is to avoid copying the -faltivec flag when the action
> being
> taken is to invoke the assembler or the preprocessor.
> 
> I've verified that this fixes the test case in question without
> introducing any unit-test or test-suite regressions.  I also verified
> that preprocessing a file requiring altivec extensions (like "vector
> float x;") with the revised Clang and then compiling the resulting
> preprocessed file still works correctly.
> 
> However, I really don't know anything about how all the driver
> machinery
> works, so I'd appreciate some extra eyes on this before I commit.
>  I'm
> CC'ing a few folks that were suggested.
> 
> For what it's worth, the test case in question is fixed by the
> isa<PreprocessJobAction> test.  The other test is there just because
> it
> makes sense to me.
> 
> I will add the original test from the PR as a unit test if this
> approach
> passes muster.

I think that this makes sense; so the job action is not available from within Frontend/CompilerInvocation.cpp where the file is actually included?

To confirm, if you compile something with clang that crashes, thus generating a preprocessed input file, the contents of altivec.h will no longer be copied into that file, correct?

 -Hal

> 
> Thanks,
> Bill
> 
> 
> Index: lib/Driver/Tools.cpp
> ===================================================================
> --- lib/Driver/Tools.cpp	(revision 184947)
> +++ lib/Driver/Tools.cpp	(working copy)
> @@ -2844,7 +2844,10 @@ void Clang::ConstructJob(Compilation &C, const
> Job
>    Args.AddLastArg(CmdArgs, options::OPT_flimit_debug_info);
>    Args.AddLastArg(CmdArgs, options::OPT_fno_limit_debug_info);
>    Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names);
> -  Args.AddLastArg(CmdArgs, options::OPT_faltivec);
> +  // -faltivec causes inclusion of altivec.h, which makes no sense
> for
> +  // an assembly or preprocess action.
> +  if (!isa<AssembleJobAction>(JA) && !isa<PreprocessJobAction>(JA))
> +    Args.AddLastArg(CmdArgs, options::OPT_faltivec);
>    Args.AddLastArg(CmdArgs,
>    options::OPT_fdiagnostics_show_template_tree);
>    Args.AddLastArg(CmdArgs, options::OPT_fno_elide_type);
>  
> 
> 
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory