[llvm-dev] How to force an unused function declaration in clang

[Soham Sinha via llvm-dev]

For the same reason GCC allowed the attribute. Even if I want to use/inline
a function later on in the pipeline.

Regards,
Soham Sinha
PhD Student, Department of Computer Science
Boston University


On Tue, Jun 26, 2018 at 8:30 AM mayuyu.io <admin at mayuyu.io> wrote:

> Out of curiosity, how does an unused declaration affect the emitted object
> file
>
> Zhang
>
> > 在 2018年6月26日，08:48，Soham Sinha via llvm-dev <llvm-dev at lists.llvm.org>
> 写道：
> >
> > clang doesn't seem to respect __attribute__((used)) in C functions. Even
> if I declare a function like the following:   __attribute__((used)) void
> function(), then also it doesn't declare the function in its IR file if I
> don't use the function. Is there any other way to force the declaration of
> "unused" function declarations with clang.
> >
> > I have hacked in clang 6.0.0 in
> tools/clang/lib/CodeGen/CodeGenModule.cpp file. I changed in EmitGlobal
> function to detect if the function has "used" attribute and then if it has
> then use "GetOrCreateLLVMFunction" this to create the function declaration.
> However, this hack fails in some other cases. Therefore I am looking for a
> proper way to do this.
> >
> > Regards,
> > Soham Sinha
> > PhD Student, Department of Computer Science
> > Boston University
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
>
>
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