[lldb-dev] interesting note on build times: configure/make vs. cmake/ninja

[Todd Fiala]

Another few notes for Ubuntu 12.04 users:

   - I did need to custom build a newer cmake.  Specifically, I built
   version cmake-2.8.12.2.
   - Do not make the mistake I apparently did where I tried 'sudo apt-get
   install ninja' and got something else installed on my system.  I ended up
   building ninja from the git repository.  Specifically, from git://
   github.com/martine/ninja.git, from commit
   84986af6fdeae3f649f2bf884b20f644bc370e48 from Thu Jan 23 08:29:38 2014
   -0800.  If you hit some silliness about not being able to run your C
   compiler and trying to run ninja from /usr/sbin/ninja, start a new cmake
   directory since cmake cached the wrong ninja.

The cmake command I ran is this:

/usr/local/cmake/cmake-current/bin/cmake -GNinja -DCMAKE_CXX_COMPILER=g++
-DCMAKE_C_COMPILER=gcc -DLLVM_ENABLE_CXX11=ON
-DCMAKE_CXX_FLAGS=-I$HOME/lldb/tools/libedit/include
-DCMAKE_EXE_LINKER_FLAGS=-L$HOME/lldb/tools/libedit/linux_x86-64/lib ../llvm


   - I have a gcc 4.8.2 in my path, and I need to tell cmake to use the
   g++/gcc from my path rather than going straight for /usr/bin/gcc and
   /usr/bin/g++.
   - I need to tell the compiler where to find our newer libedit.  You may
   recall that the stock Ubuntu 12.04 libedit is not new enough for the
   current code we use, so we have a separate libedit that we built from a
   configure-enabled build.
   - Note Ubuntu 13.10 does not need a newer gcc/g++ - 4.8.1 is fine, as is
   the libedit-dev package that it includes.  If you're building there (or
   newer), you can drop off the -DCMAKE_*_COMPILER flags and the libedit
   tweaks.

Running ninja looks like this:

ninja

ninja automatically uses as many processors as you have, so no need to
guess a good -j number as in (g)make.

Running the tests looks like this:

ninja check-lldb

I am now looking at a few failures that I got when I ran ninja check-lldb:
they might be related to the way I changed the build, so I'm first going to
verify if they show up with make/configure.

OK (skipped=1, expected failures=1)
Ran 276 tests.
Failing Tests (5)
FAIL: LLDB (suite) :: TestSTTYBeforeAndAfter.py (Linux
tfiala2.mtv.corp.google.com 3.2.5-gg1336 #1 SMP Thu Aug 29 02:37:18 PDT
2013 x86_64 x86_64)
FAIL: LLDB (suite) :: TestSingleQuoteInFilename.py (Linux
tfiala2.mtv.corp.google.com 3.2.5-gg1336 #1 SMP Thu Aug 29 02:37:18 PDT
2013 x86_64 x86_64)
FAIL: LLDB (suite) :: TestCompletion.py (Linux
tfiala2.mtv.corp.google.com3.2.5-gg1336 #1 SMP Thu Aug 29 02:37:18 PDT
2013 x86_64 x86_64)
FAIL: LLDB (suite) :: TestCommandRegex.py (Linux
tfiala2.mtv.corp.google.com3.2.5-gg1336 #1 SMP Thu Aug 29 02:37:18 PDT
2013 x86_64 x86_64)
FAIL: LLDB (suite) :: TestConvenienceVariables.py (Linux
tfiala2.mtv.corp.google.com 3.2.5-gg1336 #1 SMP Thu Aug 29 02:37:18 PDT
2013 x86_64 x86_64)
ninja: build stopped: subcommand failed.

That last one has been failing intermittently for me (it's failed about 3
times this week, which tells me the python ref count issue I fixed last
week maybe didn't totally clear that up).  The rest look new to me.


On Wed, Feb 5, 2014 at 12:59 PM, Todd Fiala <tfiala at google.com> wrote:

> Hi all,
>
> Just thought I'd pass along that I've just did a build time comparison
> between our standard lldb build setup: configure + (g)make (i.e. configure
> && make -j32), vs. cmake + ninja (i.e. cmake -GNinja && ninja).  On an HP
> z620 with 32 virtual procs on ssd, it takes me just under 10 minutes to
> build lldb with configure/make.  The same machine with ninja + cmake takes
> 4.25 minutes.  *huge* speedup.
>
> We'll be moving in that direction on our dev setups based on that change.
>  If for some reason we hit any hiccups with that, I'll be sure to tell you
> about them.
> --
>  Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>



-- 
Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/lldb-dev/attachments/20140205/b00ef802/attachment.html>