[llvm] r247305 - [CMake] Fix Xcode build with LLVM_ENABLE_OBJLIB.

[Jordan Rose via llvm-commits]

Author: jrose
Date: Thu Sep 10 12:18:51 2015
New Revision: 247305

URL: http://llvm.org/viewvc/llvm-project?rev=247305&view=rev
Log:
[CMake] Fix Xcode build with LLVM_ENABLE_OBJLIB.

This amends chapuni's r246156 to handle an Xcode quirk, one even called out
in the CMake documentation:

    Some native build systems may not like targets that have only object files,
    so consider adding at least one real source file to any target that
    references $<TARGET_OBJECTS:objlib>.

I've limited the scope of this hack to Xcode for now.

Added:
    llvm/trunk/cmake/dummy.cpp
Modified:
    llvm/trunk/cmake/modules/AddLLVM.cmake

Added: llvm/trunk/cmake/dummy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/cmake/dummy.cpp?rev=247305&view=auto
==============================================================================
--- llvm/trunk/cmake/dummy.cpp (added)
+++ llvm/trunk/cmake/dummy.cpp Thu Sep 10 12:18:51 2015
@@ -0,0 +1 @@
+typedef int dummy;

Modified: llvm/trunk/cmake/modules/AddLLVM.cmake
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/cmake/modules/AddLLVM.cmake?rev=247305&r1=247304&r2=247305&view=diff
==============================================================================
--- llvm/trunk/cmake/modules/AddLLVM.cmake (original)
+++ llvm/trunk/cmake/modules/AddLLVM.cmake Thu Sep 10 12:18:51 2015
@@ -590,6 +590,12 @@ macro(add_llvm_executable name)
 
   add_windows_version_resource_file(ALL_FILES ${ALL_FILES})
 
+  if(XCODE)
+    # Note: the dummy.cpp source file provides no definitions. However,
+    # it forces Xcode to properly link the static library.
+    list(APPEND ALL_FILES "${LLVM_SOURCE_DIR}/cmake/dummy.cpp")
+  endif()
+
   if( EXCLUDE_FROM_ALL )
     add_executable(${name} EXCLUDE_FROM_ALL ${ALL_FILES})
   else()