[llvm-dev] Making lambda function name consistent with GCC?

[Xun Li via llvm-dev]

Filed https://bugs.llvm.org/show_bug.cgi?id=50209.
Thanks.

On Mon, May 3, 2021 at 11:03 AM Tom Stellard <tstellar at redhat.com> wrote:
>
> On 4/30/21 9:41 AM, Xun Li via llvm-dev wrote:
> > Hi,
> >
> > I noticed that when compiling lambda functions, the generated function
> > names use different conventions than GCC.
> > Example: https://godbolt.org/z/5qvqKqEe6
> > The lambda in Clang is named "_Z3barIZ3foovE3$_0EvT_", while the one
> > in GCC is named "_Z3barIZ3foovEUlvE_EvT_". Their demangled names are
> > also different ("void bar<foo()::$_0>(foo()::$_0)" vs "void
> > bar<foo()::{lambda()#1}>(foo()::{lambda()#1})").
> > Lambdas are not covered by the ABI so this is OK.
> > However there are use-cases where I find it very inconvenient when
> > they generate different names. For example, if we are to compare the
> > performance difference of the same software compiled under Clang and
> > GCC, the perf stack traces will look very different because of the
> > naming differences, making it hard to compare.
> > Is there any particular reason that Clang uses a different naming
> > convention for lambdas, and would there be push-backs if we were to
> > make it consistent with GCC?
>
> Can you file a bug for this?
>
> -Tom
>
> > Thanks.
> >
>


-- 
Xun