llvm dev - Feb 2006 - [LLVMdev] Using llvm-gcc with a simple program and the '-c' option

Chris Lattner wrote:
> On Sun, 26 Feb 2006, Wink Saville wrote:
>> I then do the following in my makefile:
>>
>> llvm-gcc -c t1.c -o t1.bc
>> llvm-gcc -c t1sub1.c -o t1sub1.bc
>> llvm-gcc -c t1sub2.c -o t1sub2.bc
>> llvm-ar r t1.a t1sub1.bc t1sub2.bc
>> llvm-ar: creating t1.a
>> llvm-ld -o t1.app t1.bc t1.a /opt/llvm-1.6/llvm-gcc/lib/libcrtend.a
>> llvm-ld: warning: Cannot find library 'crtend'
>
> Try passing "-L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend" to llvm-ld. 
This didn't work for me:
llvm-ld -o t1.app t1.bc t1.a -L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend.a

I get two warning's about library 'crtend' missing
> Alternatively, instead of using llvm-ld, just use gccld to link like 
> this:
>
> llvm-gcc -o t1.app t1.bc t1.a
>
Yes this works, but not native
> ... which should work.
>
>> llc t1.app.bc -o t1.app.s
>> gcc -m32 t1.app.s -o t1
>
> If you want a native app, try this:
>
> llvm-gcc -o t1.app t1.bc t1.a -Wl,-native
>
> ... which will invoke llc and the assembler for you.  This will also 
> fix the "script + bc" issue.
Yes this works and doesn't generate the script but since I'm using an 
amd64 with linux the result doesn't run because I need the -m32.
>
> -Chris
>
Actually, the point of the above was to understand how the flow native 
and to see what difficulties I ran into.

Is it a bug that I get the "llvm-ld: warning: Cannot find library 
'crtend'"? If so, is it likely to be in llvm code and would it be 
something you'd let a neophyte to track down?

Wink

On Mon, 2006-02-27 at 20:43 -0800, Wink Saville wrote:
> > Try passing "-L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend" to
llvm-ld.
> This didn't work for me:
> llvm-ld -o t1.app t1.bc t1.a -L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend.a
> 
> I get two warning's about library 'crtend' missing
> 
You didn't get the instructions quite right. The option is -lcrtend not
-lcrtend.a

Reid.
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Reid Spencer wrote:
> On Mon, 2006-02-27 at 20:43 -0800, Wink Saville wrote:
>   
>>> Try passing "-L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend" to
llvm-ld.
>>>       
>> This didn't work for me:
>> llvm-ld -o t1.app t1.bc t1.a -L/opt/llvm-1.6/llvm-gcc/lib/ -lcrtend.a
>>
>> I get two warning's about library 'crtend' missing
>>
>>     
>
> You didn't get the instructions quite right. The option is -lcrtend not
> -lcrtend.a
>
> Reid.
>   
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Actually, I didn't have the ".a" just -lcrtend.

In possibly related news I just checked out the latest llvm from cvs and 
compiled it. Guess what, there were 6 warnings in the output and 3 of 
them were "gccld: warning: Cannot find library 'crtend'". The
last one
was just before the end:

llvm[4]: Linking Debug Object Library stkr_compiler.o
make[4]: Leaving directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/lib/compiler'
make[4]: Entering directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/lib/runtime'
llvm[4]: Compiling stacker_rt.c for Debug build (bytecode)
llvm[4]: Compiling stacker_rt.ll to stacker_rt.bc for Debug build (bytecode)
llvm[4]: Building Debug Bytecode Module stkr_runtime.bc
gccld: warning: Cannot find library 'crtend'
make[4]: Leaving directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/lib/runtime'
make[3]: Leaving directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/lib'
make[3]: Entering directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/tools'
make[4]: Entering directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/tools/stkrc'
llvm[4]: Compiling stkrc.cpp for Debug build
llvm[4]: Linking Debug executable stkrc
llvm[4]: ======= Finished Linking Debug Executable stkrc
make[4]: Leaving directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/tools/stkrc'
make[3]: Leaving directory 
`/home/wink/prgs/llvm-cvs/llvm/projects/Stacker/tools'
make[2]: Leaving directory `/home/wink/prgs/llvm-cvs/llvm/projects/Stacker'
make[1]: Leaving directory `/home/wink/prgs/llvm-cvs/llvm/projects'

I haven't tried seeing if anything works (getting past my bed time:), 
but could this have something to do with my using X86-64 (Amd64)? Also, 
I'm using gcc-4.0.2 and glibc appears to be 2.3.5 (symbolic link from 
libc.so.6 is libc-2.3.5.so).

Note: I'm new to linux, in case it wasn't obvious.

Cheers,

Wink

On Mon, 27 Feb 2006, Wink Saville wrote:
>> If you want a native app, try this:
>> 
>> llvm-gcc -o t1.app t1.bc t1.a -Wl,-native
>> 
>> ... which will invoke llc and the assembler for you.  This will also
fix
>> the "script + bc" issue.
> Yes this works and doesn't generate the script but since I'm using
an amd64
> with linux the result doesn't run because I need the -m32.
I would suggest hacking llvm::GenerateNative in 
tools/gccld/GenerateCode.cpp to pass it.

-Chris

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