add -fpic flags for old cmake

Author: spinpx

llvm_mode/dfsan_rt/CMakeLists.txt

@@ -27,6 +27,7 @@ set(DFSAN_SUPPORTED_ARCH ${X86_64}) #  ${MIPS64} ${ARM64}
 set(SANITIZER_COMMON_SUPPORTED_ARCH ${X86_64}) #  ${MIPS64} ${ARM64}
 
 list(APPEND SANITIZER_COMMON_CFLAGS -O3)
+list(APPEND SANITIZER_COMMON_CFLAGS -fPIC)
 
 include(CheckIncludeFile)
 check_include_file(rpc/xdr.h HAVE_RPC_XDR_H)

llvm_mode/external_lib/CMakeLists.txt

@@ -1,4 +1,6 @@
 
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
 ## default taint models for IO and memory allocation.
 add_library(DFSanIO STATIC io_func.c stdalloc.c)
 install (TARGETS DFSanIO DESTINATION ${ANGORA_LIB_DIR})

llvm_mode/external_lib/Makefile

@@ -36,7 +36,7 @@ endif()
 
 set (CMAKE_CXX_STANDARD 11)
 # fix pass bug: https://github.com/sampsyo/llvm-pass-skeleton/issues/7#issuecomment-401834287
-set (CMAKE_MODULE_LINKER_FLAGS "-Wl,-znodelete")
+set (CMAKE_MODULE_LINKER_FLAGS "${CMAKE_CXX_LINK_FLAGS} -Wl,-znodelete")
 if(APPLE)
     # User teor2345 reports that this is required to make things work on MacOS X.
     set (CMAKE_MODULE_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} -Wl,-flat_namespace -Wl,-undefined,suppress")