llvm dev - Dec 2006 - [LLVMdev] [patch] emit .weak for zero initialized weak variables

The attached patches makes all backends print a .weak directive for
zero initialized variables. GCC does it on x86-64 and ARM. I assume
that it should be done on all architectures.

The patch also adds a test to the ARM backend? Should I copy it to all backends?

Comments?

Thanks,
Rafael

P.S.: I find the doFinalization code a bit confusing. Would you
welcome a cleanup patch?
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On Sat, 9 Dec 2006, [UTF-8] Rafael Esp?ndola wrote:
> The attached patches makes all backends print a .weak directive for
> zero initialized variables. GCC does it on x86-64 and ARM. I assume
> that it should be done on all architectures.
>
> The patch also adds a test to the ARM backend? Should I copy it to all 
> backends?
I'm not sure this is right.  C code like this:

int X;

should compile to a .comm directive, not a .weak directive, right?

-Chris

-- 
http://nondot.org/sabre/
http://llvm.org/

> I'm not sure this is right.  C code like this:
>
> int X;
>
> should compile to a .comm directive, not a .weak directive, right?
right.

According to GCC, "int  x" should compile to ".comm   x",
but "int x
__attribute__((weak))" should compile to
---------------
.weak   x
x:
        .zero   4
---------------

It looks like we have a bug in llvm-gcc, both C codes compile to
--------------------------
%x = weak global int 0
--------------------------
> -Chris
Best Regards,
Rafael