[LLVMdev] Getting a named value in llvm-c

[Duncan Sands]

Hi Bill,

On 22/11/12 01:52, Bill Hart wrote:
> That's what I am doing of course, It;s just odd that I can get a
> global by name but not a local.

actually it's not that odd, since globals variables can be accessed by name
from other compilation units, while local variables cannot.

Ciao, Duncan.

>
> Bill.
>
> On 21 November 2012 09:35, Duncan Sands <baldrick at free.fr> wrote:
>> Hi Bill,
>>
>>
>>> I am wondering if there is a way to get a value by name in the C
>>> interface for the LLVM Jit?
>>
>>
>> since a Value includes simple constants like 42 that have no name, this is
>> not possible in general.  Moreover names are usually optional and have no
>> real meaning: they are just there to make the IR easier to read (an
>> exception
>> being struct type names).
>>
>> Perhaps you could maintain a map from name to Value* in your front-end?
>>
>> Ciao, Duncan.
>>
>>>
>>> There seems to be a way to name values consistently, but no way to
>>> retrieve those LLVMValueRef's by name.
>>>
>>> I see it is possible to get a struct by name and a type by name and a
>>> function by name, and a few other esoteric things, but not a general
>>> value.
>>>
>>> The reason I am wanting this is that I am writing a language where
>>> there is a separation between the back end and the code which
>>> processes the AST. In particular, I do not have any LLVM values or
>>> types in the AST nodes themselves, only strings naming those values
>>> and types. When the back end processes the AST it looks up the
>>> relevant types and values by string name.
>>>
>>> The specific circumstance where this causes an issue is with
>>> allocating local variables. The back end code needs to access such
>>> variables at points different from where they were defined. At present
>>> I have to store the relevant LLVMValueRef's in the AST or in some
>>> other type information elsewhere in my implementation, rather than
>>> store a string name and look them up as needed.
>>>
>>> Bill.
>>> _______________________________________________
>>> 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