[LLVMdev] Why Is This Illegal?

[Chris Lattner]

On Fri, 9 Jun 2006, Reid Spencer wrote:
> Can anyone tell me where my blunder is in the following program?
> llvm-as reports:
> llvm-as: testit.ll:11: Can't store 'opaque *' into space of type 'opaque
> *'!
>
> Which doesn't seem to make sense to me. What is it that is illegal about
> storing a pointer to opaque in a space that is of type pointer to
> opaque? Is it just that you can't store pointers to opaque?

The problem is that all instances of the string "opaque" are different 
types in .ll files.  Try using something like:

%opaque1 = type opaque
%opaque2 = type opaque

at the top, then use %opaque1/%opaque2/.. whereever you need them (or use 
even better names).  This way, each distinct opaque type is only 
"mentioned" once and you are explicit about which opaque type you are 
using.

-Chris

> %path = internal constant [11 x sbyte] c"/some/path\00"
>
> implementation   ; Functions:
>
> declare opaque* %open(sbyte*)
>
> internal int %testme(int, sbyte**) {
>        %stdout = alloca opaque*
>        %pathp = getelementptr [11 x sbyte]* %path, uint 0, uint 0
>        %handle = call opaque* %open( sbyte* %pathp )
>        store opaque* %handle, opaque* %stdout                    ; This
> is line 11
> }
>
>

-Chris

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