[LLVMdev] LLVM IR generation as one of LLVM passes

[Eli Friedman]

On Mon, Nov 5, 2012 at 5:17 PM, Wojciech Daniło
<wojtek.danilo.ml at gmail.com> wrote:
> Hi!
> I'm new to LLVM and I'm planning to write a compiler, which would behave
> slighty different than all current tools.
> As an input it will not get text but it will read a file (lets assume for a
> moment, that in this file there will be a graph structure).
> Before generating IR code I want to be able to run optimalization and
> analysis passes on this graph and after these passes I want to run pass that
> will generate LLVM IR on top of previously gathered informations.
> Additional I want to be able to chose pass which will produce IR code (if
> there will be more than one such pass).
> Is it possible in LLVM? (can I generate IR inside a compilation pass and use
> passes in described way?)
>
> If the above description will be not clear, concider following construction
> (uppercase letters are passes and lowercase letters are data consumed and
> produced by each pass respectlively)
> A: file->b
> B: b->c
> C: b->d
> I1: c -> IR
> I2: d -> IR
> ... (other LLVM passes)
>
> and now I could enable passes:
> A,B and I1
> or
> A,C and I2
>
> (both of them generate IR code but differently).
>
> I would be very thankfull if something like that  could be done in LLVM and
> if yes, any further materials will be very appreciated :)
> Thank you!

See http://llvm.org/docs/WritingAnLLVMPass.html for more info on passes.

-Eli