llvm dev - Jan 2012 - [LLVMdev] How to get the string value?

Hi, if I have some LLVM code like this:

@.str = private unnamed_addr constant [7 x i8] c"in_arr\00", align 1
@.str1 = private unnamed_addr constant [8 x i8] c"in_arr2\00", align 1
@.str2 = private unnamed_addr constant [8 x i8] c"out_arr\00", align 1
...
...

  call void (...)* @_Z16fooz(i8* *getelementptr inbounds ([7 x i8]* @.str,
i64 0, i64 0)*, i32 0, i32 1024)
...

I would like to get the string value of the bold argument, but how? I know
it's a llvm::Value pointer, but it is not a llvm::GetElementPtrInst?


Thanks,
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Hi Welson Sun,
> Hi, if I have some LLVM code like this:
>
> @.str = private unnamed_addr constant [7 x i8] c"in_arr\00",
align 1
> @.str1 = private unnamed_addr constant [8 x i8] c"in_arr2\00",
align 1
> @.str2 = private unnamed_addr constant [8 x i8] c"out_arr\00",
align 1
> ...
> ...
>
>    call void (...)* @_Z16fooz(i8* *getelementptr inbounds ([7 x i8]* @.str,
i64
> 0, i64 0)*, i32 0, i32 1024)
> ...
>
> I would like to get the string value of the bold argument, but how? I know
it's
> a llvm::Value pointer, but it is not a llvm::GetElementPtrInst?
it is a ConstantExpr getelementptr.  Whenever you see something that looks like
an instruction but is printed inline inside another instruction then that means
it is actually a constant, a ConstantExpr.

Ciao, Duncan.
>
>
> Thanks,
>
>
>
>
>
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Thanks Duncan,

Yes, it is a ConstantExpr! Thank you!

Now trying to find a clue in ConstantExpr's functions to get that string :-)

Regards,
Welson

On Thu, Jan 26, 2012 at 9:04 PM, Duncan Sands <baldrick at free.fr> wrote:
> Hi Welson Sun,
>
> > Hi, if I have some LLVM code like this:
> >
> > @.str = private unnamed_addr constant [7 x i8] c"in_arr\00",
align 1
> > @.str1 = private unnamed_addr constant [8 x i8]
c"in_arr2\00", align 1
> > @.str2 = private unnamed_addr constant [8 x i8]
c"out_arr\00", align 1
> > ...
> > ...
> >
> >    call void (...)* @_Z16fooz(i8* *getelementptr inbounds ([7 x i8]*
> @.str, i64
> > 0, i64 0)*, i32 0, i32 1024)
> > ...
> >
> > I would like to get the string value of the bold argument, but how? I
> know it's
> > a llvm::Value pointer, but it is not a llvm::GetElementPtrInst?
>
> it is a ConstantExpr getelementptr.  Whenever you see something that looks
> like
> an instruction but is printed inline inside another instruction then that
> means
> it is actually a constant, a ConstantExpr.
>
> Ciao, Duncan.
>
> >
> >
> > Thanks,
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>


-- 
Welson

Phone: (408) 418-8385
Email:  welson.sun at gmail.com
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