[LLVMdev] [llvm-commits] [PATCH] Allow per-thread re-direction of outs()/errs()

[Chris Lattner]

On May 31, 2012, at 2:39 PM, Justin Holewinski wrote:

> The attached patch add the ability to programmatically re-direct outs()/errs() to an arbitrary raw_ostream instance, maintaining the raw_ostream instances in a stack structure so clients can push/pop streams at will.  The stack is also maintained in thread-local storage, so different threads can re-direct individually.  This allows for two use cases:
> 
> 1. Compilers can attach custom streams to outs()/errs() to intercept output from LLVM without needing to play with STDOUT/STDERR.
> 2. Compilers can receive LLVM output from different threads individually, instead of having all diagnostics dumped to a single stream.

This isn't the right approach.  Nothing in the library part of the compiler should be hard coding a stream to write to.  What are you trying to accomplish?

-Chris