[PATCH] D61909: Add Clang shared library with C++ exports

[Wink Saville via Phabricator via cfe-commits]

winksaville added a comment.

You mention that you're using OBJECT libraries so objects aren't built mutliples times
and in my current tests the number of steps increased by only 3, it went from 4353 to 4356,
when using this patch, which is great!

What I see in my testing of the patch is that cmake finds that the compilers support position independent code and use `-fPIC` as default:

  -- LLVM default target triple: x86_64-unknown-linux-gnu
  -- Performing Test C_SUPPORTS_FPIC
  -- Performing Test C_SUPPORTS_FPIC - Success
  -- Performing Test CXX_SUPPORTS_FPIC
  -- Performing Test CXX_SUPPORTS_FPIC - Success
  -- Building with -fPIC

And then, as expected, I see the compile command lines have `-fPIC`:

  [1/4356] /usr/bin/c++  -DGTEST_HAS_RTTI=0 ... -fPIC ...

Its my understanding that when creating shared libraries position independent code generation is required.
Is there a problem if in some scenario the OBJECT libraries were not compiled with `-fPIC`?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61909/new/

https://reviews.llvm.org/D61909