Re: Expected output of gdb.cp/no-dmgl-verbose.exp

Luis Machado via Gdb
2021-04-12T18:55:32Z

On 4/12/21 3:45 PM, Keith Seitz wrote:
> On 4/12/21 11:16 AM, Luis Machado via Gdb wrote:
>> I'm trying to determine why this particular test is failing (for both
>> aarch64-linux and x86_64-linux on Ubuntu 18.04/20.04) and what the
>> expected outcome is.
>>
>> In my case, the only symbol I see for function "f" is the following:
>>
>> "f(std::__cxx11::basic_string<char, std::char_traits<char>,
>> std::allocator<char> >)"
>>
>> There is no "f(std::string)" nor "f(std::basic_string<char,
>> std::char_traits<char>, std::allocator<char> >)" symbol.
>>
>
> Wow, such a long time ago! IIRC...

Indeed. I vaguely remember that, back in ~2011 IIRC. But obviously not
enough to figure out what was going on.

>
> This test was written to ensure that "std::string" was used
> instead of "std::basic_string<...>" (which is now called something
> else again). Something about "that's what nm and other tools tell users,
> so we should not mention the symbol's real (linkage) name, either."
>
> The "no-dmgl-verbose" refers to the DMGL_VERBOSE option
> of the demangler, which does this.
>
> There is even special logic in our typedef-replacing machinery to
> enforce this. [NOTE: `ignore_typedefs' in cp-support.c is also "out-
> of-date" wrt to this naming change. So none of that has likely been
> "working" for many years, but then at very quick glance, "nm -C" doesn't
> do this anymore, either.]

Ah, that makes it much more clear. Thanks for the explanation.

>
> I was against it then, so I certainly do not mind getting rid of this test
> or limiting it to C++ installations that typedef the "older" std::basic_string<...>
> to std::string.

I think keeping it may be more confusing than useful. I'll propose its
removal on gdb-patches@ and we'll see where we go from there.

Thanks Keith.

>
> Keith
>