[llvm-commits] [llvm] r59208 - /llvm/trunk/lib/Transforms/IPO/StripSymbols.cpp

[Chris Lattner]

On Nov 12, 2008, at 5:28 PM, Devang Patel wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=59208&view=rev
> Log:
> Really remove all debug information.

Ok.

> @@ -213,8 +220,30 @@
>     Declare->eraseFromParent();
>   }
>
> +  // Delete all dbg variables.
> +  const Type *DbgVTy = M.getTypeByName("llvm.dbg.variable.type");
> +  const Type *DbgGVTy =  
> M.getTypeByName("llvm.dbg.global_variable.type");

This isn't safe.  You can depend on the names of non-internal globals,  
but not on the names of types.  Type names can be stripped out.  Also,  
we may add new type names for debug info in the future.

> +  if (DbgVTy || DbgGVTy)
> +    for (Module::global_iterator I = M.global_begin(), E =  
> M.global_end();
> +         I != E; ++I)
> +      if (GlobalVariable *GV = dyn_cast<GlobalVariable>(I))
> +        if (GV->hasName() && GV->use_empty()
> +            && !strncmp(GV->getNameStart(), "llvm.dbg", 8)
> +            && (GV->getType()->getElementType() == DbgVTy
> +                || GV->getType()->getElementType() == DbgGVTy))
> +          DeadGlobals.push_back(GV);
> +

I don't think that matching on the names is really a sound way to go.   
How about just looping over all the globals, removing dead globals in  
the llvm.metadata section?

-Chris