From: LLVM Packaging Team <pkg-llvm-team@lists.alioth.debian.org>
Date: Sun, 18 Jun 2017 17:12:15 +0000 (+0100)
Subject: add_symbols_versioning
X-Git-Tag: archive/raspbian/1%3.9.1-10+rpi1^2~3
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=738c98dfc44911d414a8549309fe06b80d3ea449;p=llvm-toolchain-3.9.git

add_symbols_versioning

This patch adds a very simple linker script to version the lib's symbols
and thus trying to avoid crashes if an application loads two different
LLVM versions (as long as they do not share data between them).

Note that we deliberately *don't* make LLVM_3.9 depend on LLVM_3.8:
they're incompatible and the whole point of this patch is
to tell the linker that.

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Author: Lisandro Damían Nicanor Pérez Meyer <lisandro@debian.org>
Bug-Debian: https://bugs.debian.org/848368


Gbp-Pq: Name add_symbols_versioning.patch
---

diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index 26e43960..d46e179a 100644
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -74,7 +74,7 @@ function(add_llvm_symbol_exports target_name export_file)
     set(native_export_file "${target_name}.exports")
     # FIXME: Don't write the "local:" line on OpenBSD.
     add_custom_command(OUTPUT ${native_export_file}
-      COMMAND echo "{" > ${native_export_file}
+      COMMAND echo "LLVM_3.9 {" > ${native_export_file}
       COMMAND grep -q "[[:alnum:]]" ${export_file} && echo "  global:" >> ${native_export_file} || :
       COMMAND sed -e "s/$/;/" -e "s/^/    /" < ${export_file} >> ${native_export_file}
       COMMAND echo "  local: *;" >> ${native_export_file}
diff --git a/tools/llvm-shlib/CMakeLists.txt b/tools/llvm-shlib/CMakeLists.txt
index c0dd5a89..50995bcc 100644
--- a/tools/llvm-shlib/CMakeLists.txt
+++ b/tools/llvm-shlib/CMakeLists.txt
@@ -42,7 +42,7 @@ set_property(TARGET LLVM PROPERTY VERSION "1") # Append .1 to SONAME
 list(REMOVE_DUPLICATES LIB_NAMES)
 if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux" OR "${CMAKE_SYSTEM_NAME}" STREQUAL "GNU" OR "${CMAKE_SYSTEM_NAME}" STREQUAL "kFreeBSD") # FIXME: It should be "GNU ld for elf"
   # GNU ld doesn't resolve symbols in the version script.
-  set(LIB_NAMES -Wl,--whole-archive ${LIB_NAMES} -Wl,--no-whole-archive)
+  set(LIB_NAMES -Wl,--version-script,${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map -Wl,--whole-archive ${LIB_NAMES} -Wl,--no-whole-archive)
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
   set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
 endif()
diff --git a/tools/llvm-shlib/simple_version_script.map b/tools/llvm-shlib/simple_version_script.map
new file mode 100644
index 00000000..1d908893
--- /dev/null
+++ b/tools/llvm-shlib/simple_version_script.map
@@ -0,0 +1 @@
+LLVM_3.9 { global: *; };