[cfe-dev] Too much time to compile clang. Suggestions for a starter?

[Jonas Hahnfeld via cfe-dev]

A few links that Google found in a simple search:
  - this thread: 
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106186.html
  - https://llvm.org/devmtg/2015-04/slides/eurollvm-2015-build.pdf and 
these two blog posts: 
https://blogs.s-osg.org/an-introduction-to-accelerating-your-build-with-clang/ 
and 
https://blogs.s-osg.org/a-conclusion-to-accelerating-your-build-with-clang/

I personally took most of the advices from the last blog posts:
  - Ninja, use Clang to build
  - for Debug builds: -DBUILD_SHARED_LIBS=ON -DLLVM_USE_SPLIT_DWARF=ON 
-DLLVM_OPTIMIZED_TABLEGEN=ON

Cheers,
Jonas

Am 2017-10-21 05:11, schrieb rNoz via cfe-dev:
> I would like to start "touching" a bit the code, trying to create some
> functionalities, but I have no idea where to start, and I will need
> many trials/tests...
> 
> So, one thing I was expecting is fast times to try
> (Modify-Compile-Run).
> 
> I did:
> 
> make clang
> and it needed like 3-4 hours. I am ok with that.
> 
> Then, I add some "stupid" statement like 'int a = 3;' somewhere in
> llvm/tools/clang/lib/Frontend/Rewrite/FixItRewriter.cpp
> (FixitRewriter::Diag), and it needed:
> - 6.57S. TO COMPILE THE TARGET ('MAKE CLANGREWRITEFRONTEND').
> - 4MIN 36.36S TO LINK AND BUILD CLANG (`MAKE CLANG`).
> In both cases it spends almost all the time LINKING (first to a static
> lib, then to the clang binary itself).
> 
> This is really a lot of time to try bit a bit without knowledge of the
> whole clang, compiling process, etc. Waiting up to is just really time
> consuming.
> 
> What would you do to try the modifications faster?
> 
> Any recomendation/blog/guide to follow as a starter trying to modify a
> bit the codebase of clang?
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev