Use -Wl,defs when linking.

ELF linkers by default allow shared libraries to contain undefined references
and it is up to the dynamic linker to look for them.

On COFF and MachO, that is not the case.

This creates a situation where a .so might build on an ELF system, but the build
of the corresponding .dylib or .dll will fail.

This patch changes the cmake build to use -Wl,-z,defs when linking and updates
the dependencies so that -DBUILD_SHARED_LIBS=ON build still works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226611 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 2ee0dd5b1b73414497ed20ca9d899eaf4660cb41..e60018e6a0dc9e610575e87afca8b44fae09e4f3 100644 (file)
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -104,6 +104,13 @@ if(APPLE)
   set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
 endif()
 
+# Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
+# build might work on ELF but fail on MachO/COFF.
+if(NOT (${CMAKE_SYSTEM_NAME} MATCHES "Darwin" OR WIN32))
+  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
+endif()
+
+
 function(append value)
   foreach(variable ${ARGN})
     set(${variable} "${${variable}} ${value}" PARENT_SCOPE)

diff --git a/utils/unittest/CMakeLists.txt b/utils/unittest/CMakeLists.txt
index b6d2d6d9e0e99df82067d6182f3b3c9c15027538..7ac894dff14f3e7d5e99a134e5d84c1175ef4164 100644 (file)
--- a/utils/unittest/CMakeLists.txt
+++ b/utils/unittest/CMakeLists.txt
@@ -38,11 +38,20 @@ if(MSVC AND MSVC_VERSION EQUAL 1700)
   add_definitions(-D_VARIADIC_MAX=10)
 endif ()
 
+set(LIBS
+  LLVMSupport # Depends on llvm::raw_ostream
+)
+
+find_library(PTHREAD_LIBRARY_PATH pthread)
+if (PTHREAD_LIBRARY_PATH)
+  list(APPEND LIBS pthread)
+endif()
+
 add_llvm_library(gtest
   googletest/src/gtest-all.cc
 
   LINK_LIBS
-  LLVMSupport # Depends on llvm::raw_ostream
-  )
+  ${LIBS}
+)
 
 add_subdirectory(UnitTestMain)