[LLVMdev] Enable debug for MSP430

[Rafael Espíndola]

On 3 September 2014 10:32, Iain Sandoe <iain at codesourcery.com> wrote:
> Hi Gents,
>
> For those of us with out-of-tree backends which are not 32bit, the msp430 backend is a useful vehicle for examining changes and testing out ideas.
>
> So I was wondering about enabling debug output on the MSP430 backend so that I can illustrate a few issues to Adrian and you on the variable pieces side.  (there doesn't appear to be any specific person claiming the msp430 code right now).
>
> I have a question tho.
>
> the following patch :
>
> diff --git a/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp b/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> index df1aa1a..844db93 100644
> --- a/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> +++ b/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> @@ -24,4 +24,6 @@ MSP430MCAsmInfo::MSP430MCAsmInfo(StringRef TT) {
>
>    AlignmentIsInBytes = false;
>    UsesELFSectionDirectiveForBSS = true;
> +
> +  SupportsDebugInformation = true;
>  }
>
>
> does, indeed enable debug - but NOT .debug_frame (and IIRC some of the variable range info goes missing).
>
> it needs:
>
> diff --git a/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp b/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> index df1aa1a..e7e0550 100644
> --- a/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> +++ b/llvm/lib/Target/MSP430/MCTargetDesc/MSP430MCAsmInfo.cpp
> @@ -24,4 +24,7 @@ MSP430MCAsmInfo::MSP430MCAsmInfo(StringRef TT) {
>
>    AlignmentIsInBytes = false;
>    UsesELFSectionDirectiveForBSS = true;
> +
> +  SupportsDebugInformation = true;
> +  ExceptionsType = ExceptionHandling::DwarfCFI;
>  }
>
> to make the debug_frame stuff happen.
>
> Is that intentional?
> (it's not a big deal, just a bit non-intuitive for backends which have no exception support).

I think that is the case. ExceptionsType is probably just a bad name
for the frame unwind format.

Cheers,
Rafael