[cfe-dev] Wframe-larger-than flag bug

[David Blaikie via cfe-dev]

Doesn't look like it, no.

I wouldn't recommend using -Wframe-larger-than and -save-temps (even
without -Werror) really, since that seems to crash the compiler, there's
probably no great guarantees about what that's doing.

On Sat, Jan 25, 2020 at 10:40 PM Ohad Alali <ohad.alali at gmail.com> wrote:

> Just to clarify, I cannot use flags -Wframe-larger-than, -Werror and
> -save-temps=obj and get error instead of warning. right?
>
> ‫בתאריך יום א׳, 26 בינו׳ 2020 ב-8:35 מאת ‪Ohad Alali‬‏ <‪
> ohad.alali at gmail.com‬‏>:‬
>
>> Thanks
>>
>> ‫בתאריך יום א׳, 26 בינו׳ 2020 ב-5:56 מאת ‪David Blaikie‬‏ <‪
>> dblaikie at gmail.com‬‏>:‬
>>
>>> Ah, right, sorry I didn't reproduce your steps exactly - thanks for
>>> highlighting the save-temps aspect.
>>>
>>> Yeah, testing this with clang trunk (which, on godbolt, is built with
>>> assertions enabled) this crashes the compiler. Something about
>>> frame-larger-than doesn't work with save-temps, which doesn't super
>>> surprise me, -Wframe-larger-than with -fsyntax-only doesn't produce any
>>> warning (frame-larger-than is implemented in the code generation pipeline,
>>> as much as we try to avoid doing that for warnings in clang, this one's an
>>> exception).
>>>
>>>
>>> On Sat, Jan 25, 2020 at 2:15 PM Ohad Alali <ohad.alali at gmail.com> wrote:
>>>
>>>> Thanks for your response.
>>>> I've opened your link and it's seems that clang (trunk) is not handle
>>>> the flag -save-temps=obj. compilation with -save-temps:
>>>> https://godbolt.org/z/-neaMs
>>>> When changing the compiler to clang v0.8, same behaviour as describe
>>>> before.
>>>> with flag -save-temps=obj: https://godbolt.org/z/gzpFGD
>>>> without flag -save-temps=obj: https://godbolt.org/z/5uABvL
>>>>
>>>> Thanks,
>>>> Ohad
>>>>
>>>>
>>>>
>>>> ‫בתאריך שבת, 25 בינו׳ 2020 ב-8:16 מאת ‪David Blaikie‬‏ <‪
>>>> dblaikie at gmail.com‬‏>:‬
>>>>
>>>>> Works for me: https://godbolt.org/z/kMijQ7
>>>>>
>>>>> On Sun, Jan 5, 2020 at 6:45 AM Ohad Alali via cfe-dev <
>>>>> cfe-dev at lists.llvm.org> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I'm compiling my project with clang version 7.0.0-3.
>>>>>> I added compilation flag frame-larger-than in order to warning using
>>>>>> more than 1024 bytes.
>>>>>>
>>>>>> clang indeed warning as expected, but when I added -Werror in order
>>>>>> to treat the warning as error clang ignore this flag and it stays warning.
>>>>>>
>>>>>> the compilation flags include also save-temps=obj, when I remove this
>>>>>> flag the warning treated as error.
>>>>>>
>>>>>> Does save-temps flag should be related to -Werror or
>>>>>> -Wframe-larger-than?
>>>>>>
>>>>>> full compilation flags:
>>>>>> clang++-7 -D_SYS_LINUX_ -D_HOSTSYS_LINUX_ -D_CPU_  -D_SYS64_
>>>>>> -D_DEBUG_ -O2  -Wframe-larger-than=1024 -MD -Wall -save-temps=obj -Wextra
>>>>>> -Wshadow -Werror -g -ggdb -fPIC
>>>>>>
>>>>>> Thanks,
>>>>>> Ohad
>>>>>> _______________________________________________
>>>>>> cfe-dev mailing list
>>>>>> cfe-dev at lists.llvm.org
>>>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>>>>>>
>>>>>
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