[clang] [clang-shlib] Add symbol versioning to all symbols (PR #110758)

[Tom Stellard via cfe-commits]

https://github.com/tstellar created https://github.com/llvm/llvm-project/pull/110758

We do the same thing for libLLVM.so.  This should help avoid issues when an applications loads two different versions of the library at the same time.

>From 59673ed97d92df34d6f662da5a51f6e28806b5af Mon Sep 17 00:00:00 2001
From: Tom Stellard <tstellar at redhat.com>
Date: Thu, 26 Sep 2024 13:53:18 +0000
Subject: [PATCH] [clang-shlib] Add symbol versioning to all symbols

We do the same thing for libLLVM.so.  This should help avoid issues
when an applications loads two different versions of the library at
the same time.
---
 clang/tools/clang-shlib/CMakeLists.txt               | 7 +++++++
 clang/tools/clang-shlib/simple_version_script.map.in | 1 +
 2 files changed, 8 insertions(+)
 create mode 100644 clang/tools/clang-shlib/simple_version_script.map.in

diff --git a/clang/tools/clang-shlib/CMakeLists.txt b/clang/tools/clang-shlib/CMakeLists.txt
index 298d3a9d18fec8..004ce2897960ca 100644
--- a/clang/tools/clang-shlib/CMakeLists.txt
+++ b/clang/tools/clang-shlib/CMakeLists.txt
@@ -61,3 +61,10 @@ if (MINGW OR CYGWIN)
   # make sure we export all symbols despite potential dllexports.
   target_link_options(clang-cpp PRIVATE LINKER:--export-all-symbols)
 endif()
+
+# Solaris ld does not accept global: *; so there is no way to version *all* global symbols
+if (NOT LLVM_LINKER_IS_SOLARISLD AND NOT MINGW)
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map.in
+	         ${CMAKE_CURRENT_BINARY_DIR}/simple_version_script.map)
+  target_link_options(clang-cpp PRIVATE -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/simple_version_script.map)
+endif()
diff --git a/clang/tools/clang-shlib/simple_version_script.map.in b/clang/tools/clang-shlib/simple_version_script.map.in
new file mode 100644
index 00000000000000..cb2306d1f59682
--- /dev/null
+++ b/clang/tools/clang-shlib/simple_version_script.map.in
@@ -0,0 +1 @@
+ at LLVM_SHLIB_SYMBOL_VERSION@ { global: *; };