[llvm] r243682 - Add a TargetMachine hook that verifies DataLayout compatibility

[Mehdi Amini]

It is very late to do that (override the DL).
My impression is that it is the responsibility of the tool that will read older bitcode to handle that before feeding it to any LLVM pass.

— 
Mehdi

> On Jul 30, 2015, at 4:41 PM, Eric Christopher <echristo at gmail.com> wrote:
> 
> So, I know I approved this, but I just thought (and by "I just thought" I mean someone said "hey, what about") about older bitcode that has a target that changed their DataLayout representation? Now they'll get an assert. Perhaps a better thing would be to do a warning in -debug mode and set the module DL to the TargetMachine DL in this case?
> 
> -eric
> 
> On Thu, Jul 30, 2015 at 1:43 PM Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>> wrote:
> Author: mehdi_amini
> Date: Thu Jul 30 15:33:18 2015
> New Revision: 243682
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=243682&view=rev <http://llvm.org/viewvc/llvm-project?rev=243682&view=rev>
> Log:
> Add a TargetMachine hook that verifies DataLayout compatibility
> 
> Summary: Also provide the associated assertion when CodeGen starts.
> 
> Reviewers: echristo
> 
> Subscribers: llvm-commits
> 
> Differential Revision: http://reviews.llvm.org/D11654 <http://reviews.llvm.org/D11654>
> 
> From: Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>>
> 
> Modified:
>     llvm/trunk/include/llvm/Target/TargetMachine.h
>     llvm/trunk/lib/CodeGen/MachineFunction.cpp
> 
> Modified: llvm/trunk/include/llvm/Target/TargetMachine.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetMachine.h?rev=243682&r1=243681&r2=243682&view=diff <http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetMachine.h?rev=243682&r1=243681&r2=243682&view=diff>
> ==============================================================================
> --- llvm/trunk/include/llvm/Target/TargetMachine.h (original)
> +++ llvm/trunk/include/llvm/Target/TargetMachine.h Thu Jul 30 15:33:18 2015
> @@ -133,6 +133,15 @@ public:
>    /// Create a DataLayout.
>    const DataLayout createDataLayout() const { return DL; }
> 
> +  /// Test if a DataLayout if compatible with the CodeGen for this target.
> +  ///
> +  /// The LLVM Module owns a DataLayout that is used for the target independent
> +  /// optimizations and code generation. This hook provides a target specific
> +  /// check on the validity of this DataLayout.
> +  bool isCompatibleDataLayout(const DataLayout &Candidate) const {
> +    return DL == Candidate;
> +  }
> +
>    /// Get the pointer size for this target.
>    ///
>    /// This is the only time the DataLayout in the TargetMachine is used.
> 
> Modified: llvm/trunk/lib/CodeGen/MachineFunction.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineFunction.cpp?rev=243682&r1=243681&r2=243682&view=diff <http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineFunction.cpp?rev=243682&r1=243681&r2=243682&view=diff>
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/MachineFunction.cpp (original)
> +++ llvm/trunk/lib/CodeGen/MachineFunction.cpp Thu Jul 30 15:33:18 2015
> @@ -85,6 +85,10 @@ MachineFunction::MachineFunction(const F
> 
>    FunctionNumber = FunctionNum;
>    JumpTableInfo = nullptr;
> +
> +  assert(TM.isCompatibleDataLayout(getDataLayout()) &&
> +         "Can't create a MachineFunction using a Module with a "
> +         "Target-incompatible DataLayout attached\n");
>  }
> 
>  MachineFunction::~MachineFunction() {
> 
> 
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu <mailto:llvm-commits at cs.uiuc.edu>
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits <http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150730/8061e98c/attachment.html>