[llvm-commits] [llvm] r131592 - /llvm/trunk/include/llvm/Support/StandardPasses.h

[Francois Pichet]

On Wed, May 18, 2011 at 6:46 PM, David Chisnall <csdavec at swan.ac.uk> wrote:
> Author: theraven
> Date: Wed May 18 17:46:02 2011
> New Revision: 131592
>
> URL: http://llvm.org/viewvc/llvm-project?rev=131592&view=rev
> Log:
> Some better type safety enforcement in the standard pass list, along with some small tidies and some fixes for bugs that the stricter checking found.
>
>
> Modified:
>    llvm/trunk/include/llvm/Support/StandardPasses.h
>
> Modified: llvm/trunk/include/llvm/Support/StandardPasses.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/StandardPasses.h?rev=131592&r1=131591&r2=131592&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Support/StandardPasses.h (original)
> +++ llvm/trunk/include/llvm/Support/StandardPasses.h Wed May 18 17:46:02 2011
> @@ -27,6 +27,7 @@
>  #include "llvm/Transforms/IPO.h"
>
>  namespace llvm {
> +    //template<Pass*(*X)(void)> static Pass *CreatePassFn(void) { return X(); }
>
>   /// RegisterStandardPassLists solves a circular dependency problem.  The
>   /// default list of passes has to live somewhere.  It can't live in the core
> @@ -42,23 +43,36 @@
>       StandardPass::CreateVerifierPass = CreateVerifierPass;
>     }
>     private:
> +    /// Define a template function that does the casting for us, so that we can
> +    /// perform safe function pointer casts, but catch unsafe ones.
> +    template<llvm::ImmutablePass*(*X)(void)> static llvm::Pass*
> +      CreatePassFn(void) { return X(); }
> +    template<llvm::ModulePass*(*X)(void)> static llvm::Pass*
> +      CreatePassFn(void) { return X(); }
> +    template<llvm::FunctionPass*(*X)(void)> static llvm::Pass*
> +      CreatePassFn(void) { return X(); }
> +    template<llvm::Pass*(*X)(void)> static llvm::Pass*
> +      CreatePassFn(void) { return X(); }
>     static llvm::Pass *CreateVerifierPass() { return createVerifierPass(); }


Hi.. this is too much for MSVC 2010. It wont compile:

This is a reduction of the problem:
===========================
class A {};
class B {};

template<A*(*X)(void)> static void CreatePassFn(void) {  }
template<B*(*X)(void)> static void CreatePassFn(void) {  }

B* CreatePassX(void);
	
int main()
{
   CreatePassFn<CreatePassX>(); // <== error here.
   return 1;
}
===========================	

This code will compile fine with clang and gcc 4.5. MSVC 2010 will fail.
Seems like MSVC cannot deduce template arguments that are function and
that differ only by return type.

Anybody have an idea on how to redesign this to make it MSVC friendly?