[LLVMdev] llvm-ld -disable-opt behavior.

[sanjiv gupta]

On Wed, 2009-07-15 at 20:17 -0700, Daniel Dunbar wrote:
> On Wed, Jul 15, 2009 at 7:29 PM, sanjiv gupta<sanjiv.gupta at microchip.com> wrote:
> > On Wed, 2009-07-15 at 10:37 -0700, Devang Patel wrote:
> >> On Wed, Jul 15, 2009 at 9:32 AM, sanjiv gupta<sanjiv.gupta at microchip.com> wrote:
> >> > Consider the example command line below
> >> >
> >> > $ llvm-ld -disable-opt hello.bc -l std -o hello.out
> >> >
> >> > Why does -disable-opt links in all the bitcode from the libstd.so into
> >> > hello.out?
> >>
> >> ... because it just disables optimization passed. It does not disable linking.
> >>  ?
> >> -
> >> Devang
> >> ______
> > I think I did not explain the question really well.
> >
> > -disable-opt links the whole lib into the final program while not using
> > -disable-opt links in only the required symbols. Why ?
> 
> I think you are confusing the order. Probably what is happening is
> whole lib is getting linked in, then optimization is throwing away a
> bunch of stuff.
> 
> Linking works on modules at a time, so if hello.bc uses some symbol X,
> it will pull in the entire module inside the library which contains a
> definition of X.
> 
>  - Daniel
> 
Ok. so when you 
$ llvm-ld -link-as-library a.bc b.bc c.bc -o stdlib.so

The generated file stdlib.so becomes a single module. Right ?

- Sanjiv

> > - Sanjiv
> >
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