[LLVMdev] How to convert an iterator to an object pointer

[Surinder]

I have a pointer to a basic block and am iterating thru its
predecessor blocks. I want to get a pointer to the predecessor block.
How do I do it. I am using following code and it given compile time
errors.

error: cannot convert 'llvm::const_pred_iterator' to 'const
llvm::BasicBlock*' in initialization

const BasicBlock *b = PH->getParent();
// process all pred block of the current block
for (const_pred_iterator pr=pred_begin(b), esc=pred_end(b); pr!=esc; ++pr)
{ const BasicBlock *p = pr; // ************error line ****************
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[Lang Hames]

Hi Surinder,

You'll need to dereference your iterator to get a pointer: 

const BasicBlock *p = *pr;

Cheers,

Lang.

[Cameron Zwarich]

On 2011-01-30, at 8:04 PM, Surinder wrote:

> I have a pointer to a basic block and am iterating thru its
> predecessor blocks. I want to get a pointer to the predecessor block.
> How do I do it. I am using following code and it given compile time
> errors.
>
> error: cannot convert 'llvm::const_pred_iterator' to 'const
> llvm::BasicBlock*' in initialization
>
> const BasicBlock *b = PH->getParent();
> // process all pred block of the current block
> for (const_pred_iterator pr=pred_begin(b), esc=pred_end(b); pr!=esc; ++pr)
> { const BasicBlock *p = pr; // ************error line ****************

Try using *pr instead.

Cameron

[Surinder]

Thanks. *p=*pr; works. I am passing *p to dominates function of
dominator tree and it does not like *pr, but is happy with *p.