cmake: introduce option OSS_FUZZ

OSS Fuzz build environment has some specific, for example,
libFuzzer files are named in other way that in LLVM package.

Author: ligurio

CMakeLists.txt

@@ -7,6 +7,11 @@ project(luzer
 
 option(ENABLE_LUAJIT "Use LuaJIT library" OFF)
 option(LUAJIT_FRIENDLY_MODE "Use LuaJIT-friendly mode" OFF)
+option(OSS_FUZZ "Enable OSS Fuzz support" OFF)
+
+if(DEFINED ENV{OSS_FUZZ})
+  set(OSS_FUZZ ON)
+endif()
 
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 include(SetClangRTLib)

luzer/CMakeLists.txt

@@ -1,6 +1,6 @@
 SetHwArchString(ARCH)
 # LibFuzzer library in the OSS Fuzz environment has another name.
-if (DEFINED ENV{OSS_FUZZ})
+if(OSS_FUZZ)
   set(LIBFUZZER_NO_MAIN_LIB_NAME "libclang_rt.fuzzer_no_main.a")
 elseif (CMAKE_SYSTEM_NAME STREQUAL "Linux")
   set(LIBFUZZER_NO_MAIN_LIB_NAME "libclang_rt.fuzzer_no_main-${ARCH}.a")
@@ -14,7 +14,7 @@ set(LIBCLANG_ASAN_NAME "libclang_rt.asan-${ARCH}.a")
 set(LIBCLANG_UBSAN_NAME "libclang_rt.ubsan_standalone-${ARCH}.a")
 # Sanitizers libraries in the OSS Fuzz environment have different
 # names.
-if (DEFINED ENV{OSS_FUZZ})
+if(OSS_FUZZ)
   set(LIBCLANG_ASAN_NAME "libclang_rt.asan.a")
   set(LIBCLANG_UBSAN_NAME "libclang_rt.ubsan_standalone.a")
 endif()