[LLVMdev] c const

[Ryan M. Lefever]

I don't mean to be a pain, but I was thinking about this a bit more. 
Does gcc ignore the const keyword?  If not, why has LLVM chosen to 
deviate from gcc with respect to the const keyword?  If so, then why do 
we bother using const in LLVM API code?  I'm just curious and wanted to 
understand the thinking behind not preserving const.

Thanks,
Ryan

Chris Lattner wrote:
> This property isn't preserved on the llvm ir, because const can always  
> be cast away.  If you want mod information, then I suggest using the  
> aliasanalysis interface to get mod ref info for a call.
> 
> -Chris
> 
> http://nondot.org/sabre
> http://llvm.org
> 
> On Aug 8, 2007, at 12:07 AM, "Ryan M. Lefever" <lefever at crhc.uiuc.edu>  
> wrote:
> 
> 
>>How is c's const keyword translated when compiling c into llvm  
>>bytecode.
>> I'm specifically interested in const pointer function arguments.
>>Consider a function declared as follows in c:
>>
>>void f(const int* arg);
>>
>>When I examine f in llvm bytecode, how can I tell that arg is a  
>>pointer,
>>whose contents can only be read, not written.
>>
>>Regards,
>>Ryan
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>>LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> 
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-- 
Ryan M. Lefever  [http://www.crhc.uiuc.edu/~lefever/index.html]