commit 2cbaa13bbc5e114511e2235f63baa4794e1ebde3
author Louis Dionne <ldionne.2@gmail.com> Tue Jun 15 18:47:38 2021 -0400
committer Copybara-Service <copybara-worker@google.com> Thu Jul 29 15:05:10 2021 -0700
tree 08558b187a365226c499c7986775f38be30b0809
parent 488bd9657dd33fdde5fc9a8637463e039bcc2f11

[runtimes] Always build libc++, libc++abi and libunwind with -fPIC

Building the libraries with -fPIC ensures that we can link an executable
against the static libraries with -fPIE. Furthermore, there is apparently
basically no downside to building the libraries with position independent
code, since modern toolchains are sufficiently clever.

This commit enforces that we always build the runtime libraries with -fPIC.
This is another take on D104327, which instead makes the decision of whether
to build with -fPIC or not to the build script that drives the runtimes'
build.

Fixes http://llvm.org/PR43604.

Differential Revision: https://reviews.llvm.org/D104328

GitOrigin-RevId: 21c24ae9029a1fcd1c76b61b1c48b81b5c66c606

src/CMakeLists.txt

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 889d751..f07d433 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -191,6 +191,7 @@
       SOVERSION "1"
       VERSION "${LIBCXXABI_LIBRARY_VERSION}"
       DEFINE_SYMBOL ""
+      POSITION_INDEPENDENT_CODE ON
   )
 
   list(APPEND LIBCXXABI_BUILD_TARGETS "cxxabi_shared")
@@ -243,6 +244,7 @@
       COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}"
       LINK_FLAGS "${LIBCXXABI_LINK_FLAGS}"
       OUTPUT_NAME "c++abi"
+      POSITION_INDEPENDENT_CODE ON
     )
 
   if(LIBCXXABI_HERMETIC_STATIC_LIBRARY)