[LLVMdev] Living on Clang

[Diego Iastrubni]

How about building this in the CMake or auto* level we build a separate
build script for it? I attache a simple version here. It does seem to work
here. It's a shell script, which uses cmake for the building but it seems
the second stage file works. I am not really sure why a third stage is
needed, but it can be added quite easily. A windows version should be
trivial to write (next week).

A few rants about clang:
This is the first time I was able to bootstrap the whole compiler. Which is
great, don't get me wrong. But it was painfully slow, and the CPU of my
machine became *really* hot unlike with gcc. The whole building process took
more then 4 hours on this old cual core machine, while stage one took an
hour more or less (I need to do a test again, without ccache).

[elcuco at pinky ~/src/llvm] ls bootstrap-stage-2/bin/ -ltr
total 262708
-rwxrwxr-x. 1 elcuco elcuco  5641794 2010-04-19 03:12 tblgen
-rwxrwxr-x. 1 elcuco elcuco   985416 2010-04-19 04:41 FileCheck
-rwxrwxr-x. 1 elcuco elcuco     6374 2010-04-19 04:41 count
-rwxrwxr-x. 1 elcuco elcuco   122992 2010-04-19 04:41 not
-rwxrwxr-x. 1 elcuco elcuco    24101 2010-04-19 05:34 llvm-config
-rwxrwxr-x. 1 elcuco elcuco 18325933 2010-04-19 05:36 opt
-rwxrwxr-x. 1 elcuco elcuco  7705301 2010-04-19 05:36 llvm-as
-rwxrwxr-x. 1 elcuco elcuco  6671138 2010-04-19 05:36 llvm-dis
-rwxrwxr-x. 1 elcuco elcuco 31626605 2010-04-19 05:37 llvm-mc
-rwxrwxr-x. 1 elcuco elcuco 32630459 2010-04-19 05:38 llc
-rwxrwxr-x. 1 elcuco elcuco  6814656 2010-04-19 05:38 llvm-ranlib
-rwxrwxr-x. 1 elcuco elcuco  6875243 2010-04-19 05:38 llvm-ar
-rwxrwxr-x. 1 elcuco elcuco  6827605 2010-04-19 05:38 llvm-nm
-rwxrwxr-x. 1 elcuco elcuco 14608549 2010-04-19 05:39 llvm-ld
-rwxrwxr-x. 1 elcuco elcuco  7506306 2010-04-19 05:39 llvm-prof
-rwxrwxr-x. 1 elcuco elcuco  8310633 2010-04-19 05:39 llvm-link
-rwxrwxr-x. 1 elcuco elcuco 25527057 2010-04-19 05:40 lli
-rwxrwxr-x. 1 elcuco elcuco  8217315 2010-04-19 05:40 llvm-extract
-rwxrwxr-x. 1 elcuco elcuco 18994379 2010-04-19 05:42 bugpoint
-rwxrwxr-x. 1 elcuco elcuco  1011333 2010-04-19 05:43 llvm-bcanalyzer
-rwxrwxr-x. 1 elcuco elcuco     6468 2010-04-19 05:43 llvm-stub
-rwxrwxr-x. 1 elcuco elcuco    42747 2010-04-19 07:28 c-index-test
-rwxrwxr-x. 1 elcuco elcuco 60447800 2010-04-19 07:29 clang
lrwxrwxrwx. 1 elcuco elcuco       51 2010-04-19 07:29 clang++ ->
/home/elcuco/src/llvm/bootstrap-stage-2/bin/./clang


On Fri, Apr 16, 2010 at 12:27 AM, Lacey, Mark <mark.lacey at intel.com> wrote:

> > We want to make Clang great, and we need your help!
>
> Doug,
>
> I don't see any type of selfbuild target in the LLVM top level makefile.
> This would be a useful way to automate the self build process.
>
> I've used similar mechanisms before on other compilers, where you can
> trivially invoke a three phase build (first you do a full build with your
> system compiler, then you use your built compiler to do another full build,
> and then take that most recent build compiler to build yet again...). The
> build options of the last two phases are identical, and the object files
> from those last two passes are compared to ensure that they are identical.
>
> Ideally you can control the build options of the initial build and last two
> builds independently (e.g. build a compiler without optimizations and with
> assertions, and then do the last two builds with assertions disabled, and
> optimizations on) - I'm not sure how easy this is with the autoconfig based
> system LLVM/clang use, if at all.
>
> Mark
>
>
> _______________________________________________
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> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
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