[LLVMdev] Getting started with LLVM Passes

[Chris Lattner]

On Fri, 8 Jul 2005, Sean Peisert wrote:
> I am attempting to get started with LLVM passes by running the Hello
> pass.  On my FreeBSD 5.x box, I've written and compiled (with
> llvm-gcc) a Hello program, and also compiled the Hello pass in the
> lib/Transforms/Hello directory.
>
> I know that this results in a number of files, as follows:
>> ls -l LLVM/llvm/lib/Transforms/Hello/Debug/
> total 128
> -rw-r--r--  1 sean  staff   11004 Jul  8 16:25 Hello.d
> -rw-r--r--  1 sean  staff     358 Jul  8 16:25 Hello.lo
> -rw-r--r--  1 sean  staff  115984 Jul  8 16:25 Hello.o
>
> However, running the opt command results in the following error:
>
>> opt -load LLVM/llvm/lib/Transforms/Hello/Debug/Hello.lo < hello.bc > /dev/null
> Error opening 'LLVM/llvm/lib/Transforms/Hello/Debug/Hello.lo': Can't
> open :LLVM/llvm/lib/Transforms/Hello/Debug/Hello.lo: Cannot open
> "LLVM/llvm/lib/Transforms/Hello/Debug/Hello.lo.so"
>  -load request ignored.

-load works with shared objects (.so files), not libtool objects.  The 
trick is that they get built into your llvm/Debug/lib/ directory.  Try 
something like this:

opt -load LLVM/llvm/Debug/lib/libhello.so ...

-Chris

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