notes on llvmc2

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1

Being fully aware that llvmc2 is work-in-progress, here are some notes nethertheless:

I already compiled llvm, but llvm-gcc was still compiling. Now I tried the new llvmc2:

$ llvmc2 -opt -v main.c

llvm-g++ -c -x c main.c -o /tmp/llvm_KeApik/main.bc -emit-llvm

llvmc2: Can’t find program ‘llvm-g++’

  • after this, the directory /tmp/llvm_KeApik was not removed

  • why using /tmp at all? And if, why /tmp/llvm_* and not

/tmp/llvmc2_* ?

  • why calling “llvm-g++ -x c” and not “llvm-gcc” ?

  • a --dry-run switch would be nice

Now, llvm-gcc was was finally compiled and installed, so I retried:

$ rm -rf /tmp/llvm_*

$ llvmc2 -opt -v main.c

llvm-g++ -c -x c main.c -o /tmp/llvm_084K2D/main.bc -emit-llvm

opt /tmp/llvm_084K2D/main.bc -o /tmp/llvm_084K2D/main.bc-LXq9ea

opt: error opening ‘/tmp/llvm_084K2D/main.bc-LXq9ea’: file exists!

Use -f command line argument to force output

All of this is based on LLVM SVN 51761.

2

Hi Holger,

first of all, thanks for your feedback.

I already compiled llvm, but llvm-gcc was still compiling. Now I tried the new

llvmc2:

$ llvmc2 -opt -v main.c
llvm-g++ -c -x c main.c -o /tmp/llvm_KeApik/main.bc -emit-llvm
llvmc2: Can't find program 'llvm-g++'

* after this, the directory /tmp/llvm_KeApik was not removed

Strange, I couldn't reproduce this. What system are you using?

* why calling "llvm-g++ -x c" and not "llvm-gcc" ?
...
$ llvmc2 -opt -v main.c
llvm-g++ -c -x c main.c -o /tmp/llvm_084K2D/main.bc -emit-llvm
opt /tmp/llvm_084K2D/main.bc -o /tmp/llvm_084K2D/main.bc-LXq9ea
opt: error opening '/tmp/llvm_084K2D/main.bc-LXq9ea': file exists!
Use -f command line argument to force output

Thanks for reporting these issues, I've fixed them in SVN.

$ rm -rf /tmp/llvm_*

BTW, you didn't have to do this, llvmc always creates a unique temporary
directory for each invocation.

3

> I already compiled llvm, but llvm-gcc was still compiling.
> Now I tried the new

llvmc2:
> $ llvmc2 -opt -v main.c
> llvm-g++ -c -x c main.c -o /tmp/llvm_KeApik/main.bc
> -emit-llvm llvmc2: Can't find program 'llvm-g++'
>
>
> * after this, the directory /tmp/llvm_KeApik was not removed

Strange, I couldn't reproduce this. What system are you using?

Linux in the "Debian Etch" flavour.

I've now switched to SVN 51864. I tried to re-create the problem
with "rm dist/bin/llvm-gcc", but now it worked as expected: the
temp directory was removed.