llvm dev - Aug 2019 - Can I build llvm with only a handful of source files compiled for debug?

Actually, I have same question, If llvm build provides a option similar to
that, it will be lot more easier for people doing development in relatively
less (compute, storage) PC's.


On Thu, 15 Aug 2019 at 00:22, David Blaikie via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Nothing supported, though might not be too hard to do by hand.
>
> If you're having long link times, lots of disk usage, and slow gdb
startup
> time I'd recommend enabling split DWARF (LLVM_USE_SPLIT_DWARF=ON,
> and CMAKE_EXE_LINKER_FLAGS_*=-Wl,-gdb-index in cmake) if you haven't
> already.
>
> On Wed, Aug 14, 2019 at 11:40 AM Robert Henry via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> In order to minimize edit/compile/debug turn time, is there a way to
>> compile llvm tools so that the majority of the files are compiled as if
for
>> release (eg, no debug symbols), and only the handful of files that I
have
>> touched are compiled for debugging? This will reduce the load on the
file
>> system, linker and gdb tremendously.  At present, AFAICT, it's all
or
>> nothing.
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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Are you already using split DWARF & still having resource constraint
problems? (oh, you could also compress debug info,
-Wa,-compress-debug-sections)



On Wed, Aug 14, 2019 at 12:00 PM Praveen Velliengiri <
praveenvelliengiri at gmail.com> wrote:
> Actually, I have same question, If llvm build provides a option similar to
> that, it will be lot more easier for people doing development in relatively
> less (compute, storage) PC's.
>
>
> On Thu, 15 Aug 2019 at 00:22, David Blaikie via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Nothing supported, though might not be too hard to do by hand.
>>
>> If you're having long link times, lots of disk usage, and slow gdb
>> startup time I'd recommend enabling split DWARF
(LLVM_USE_SPLIT_DWARF=ON,
>> and CMAKE_EXE_LINKER_FLAGS_*=-Wl,-gdb-index in cmake) if you
haven't
>> already.
>>
>> On Wed, Aug 14, 2019 at 11:40 AM Robert Henry via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>> In order to minimize edit/compile/debug turn time, is there a way
to
>>> compile llvm tools so that the majority of the files are compiled
as if for
>>> release (eg, no debug symbols), and only the handful of files that
I have
>>> touched are compiled for debugging? This will reduce the load on
the file
>>> system, linker and gdb tremendously.  At present, AFAICT, it's
all or
>>> nothing.
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>
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Regarding resource constraint problems, I didn't build llvm on much heavier
machine previously, so it is difficult for me to tell whether my build is
taking longer than expected trivially, fresh build (+ clang, lldb) takes
time. But rebuild are actually fast.
I will use -compress-debug-sections with the full build and rebuilds and
see how fast it is :)
Making an assumption here: since debug-info is compressed, i think it may
cause a overhead for the debugger. Is it true? If so, it overhead is
observable to some extent ?

On Thu, 15 Aug 2019 at 00:33, David Blaikie <dblaikie at gmail.com> wrote:
> Are you already using split DWARF & still having resource constraint
> problems? (oh, you could also compress debug info,
> -Wa,-compress-debug-sections)
>
>
>
> On Wed, Aug 14, 2019 at 12:00 PM Praveen Velliengiri <
> praveenvelliengiri at gmail.com> wrote:
>
>> Actually, I have same question, If llvm build provides a option similar
>> to that, it will be lot more easier for people doing development in
>> relatively less (compute, storage) PC's.
>>
>>
>> On Thu, 15 Aug 2019 at 00:22, David Blaikie via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>> Nothing supported, though might not be too hard to do by hand.
>>>
>>> If you're having long link times, lots of disk usage, and slow
gdb
>>> startup time I'd recommend enabling split DWARF
(LLVM_USE_SPLIT_DWARF=ON,
>>> and CMAKE_EXE_LINKER_FLAGS_*=-Wl,-gdb-index in cmake) if you
haven't
>>> already.
>>>
>>> On Wed, Aug 14, 2019 at 11:40 AM Robert Henry via llvm-dev <
>>> llvm-dev at lists.llvm.org> wrote:
>>>
>>>> In order to minimize edit/compile/debug turn time, is there a
way to
>>>> compile llvm tools so that the majority of the files are
compiled as if for
>>>> release (eg, no debug symbols), and only the handful of files
that I have
>>>> touched are compiled for debugging? This will reduce the load
on the file
>>>> system, linker and gdb tremendously.  At present, AFAICT,
it's all or
>>>> nothing.
>>>> _______________________________________________
>>>> LLVM Developers mailing list
>>>> llvm-dev at lists.llvm.org
>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>
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