[Haskell-cafe] A question on DSL's

[CK Kashyap]

Hi,
I am not sure if I'm using DSL in the right context here but I am referring to those solutions that allow us to write code in Haskell and generate a target code source code of another language or even object code for that matter. I am aware of two ways of achieving this - 
1. Implement functions that emit the target code - that is, when the Haskell code is compiled and run, the target code is emitted
2. Modify the Haskell compiler's back end to emit the code - that is when the Haskell code is compiled the target code is emitted

I am not sure if there are more ways (hybrid perhaps) ... 

My question is,  when would I chose one approach over the other?

Regards,
Kashyap