[llvm-dev] Pardon the newbie question

[David Blaikie via llvm-dev]

On Thu, Apr 15, 2021 at 2:43 PM pawel k. via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>
> Hiya,
>
> Enormous thanks for all suggests and extensive too. Testing splitdwarf asap.
>
> Makes me think what i thought previously. We need dwarf go pdbish way.

Split DWARF provides something like this, though with some different
tradeoffs - for instance Split DWARF is easier to use in a distributed
build (since the compiler doesn't have to communicate with a separate
server while it's compiling).

> Separate dblike possibly adressable by url.

Symbol servers are another problem - even using classic DWARF you can
then strip the main binary, keep the unstripped binary and put that
unstripped binary on some kind of symbol server system (I'm not sure
if gdb supports something like that natively, but could be done
without DWARF changes).

> I was hacking pdb techno before it got sexy. I know a bit how it is organized and could try to help with architecting or designing such solution. Loved dbinfo on vstudio. Gdbish not so much.

What sort of problems have you had with gdb or the DWARF debugging
workflow more generally?

> And i was slaving on my corpo cotton plantation passively using gdb for about a decade.

(analogies to slavery aren't suitable for this community)

- Dave

>
> If catches anyones focus, lets discuss the solution.
>
> Best regards,
> Pawel Kunio
>
> czw., 15.04.2021, 23:37 użytkownik Min-Yih Hsu <minyihh at uci.edu> napisał:
>>
>> You can use `LLVM_USE_LINKER=lld` CMake variable to adopt LLD (to build LLVM). And yes, LLD takes less memory and runs faster. Here are some other tips to save memory:
>> 1. You can use `LLVM_PARALLEL_LINK_JOBS=N` (also a cmake variable) to limit the amount of parallel linker jobs to save some memory.
>>
>> 2. Build libraries as shared library via `BUILD_SHARED_LIBS=ON` CMake variable can dramatically speed up the linking time and save you some memory.
>>
>> 3. Since you’re building a Debug build (and you’re building on Linux), `LLVM_USE_SPLIT_DWARF` can dramatically reduce the size of debug info, which, to some extend, also save you some memory during link time.
>>
>> Best,
>> -Min
>> > On Apr 15, 2021, at 1:05 PM, pawel k. via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>> >
>> > Hello,
>> > Im trying to build trunk clang in debug version on oldish ubuntu with low mem. Linking lli takes ages and fails on low mem. Is there a chance building would succeed if i used lld instead of ld? If so is there an option either to force lld or whole clang toolchain use in cmake instead of default gcc (both gcc and clang are avail on system)? Otherwise I think ill stick with release.
>> >
>> > Best regards,
>> > Pawel Kunio
>> > _______________________________________________
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>> > llvm-dev at lists.llvm.org
>> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
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