Fix linking failures when compiled with Clang 9

minetest · Mar 5, 2020 · db95ff2 · db95ff2
1 parent e774d8c
commit db95ff2
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -696,7 +696,7 @@ else()
 		set(RELEASE_WARNING_FLAGS "")
 	endif()
 
-	if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+	if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 		set(WARNING_FLAGS "${WARNING_FLAGS} -Wsign-compare")
 	endif()
 	if(APPLE AND USE_LUAJIT)
@@ -713,7 +713,14 @@ else()
 	if(CMAKE_SYSTEM_NAME MATCHES "(Darwin|BSD|DragonFly)")
 		set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Os")
 	else()
-		set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -ffast-math -fomit-frame-pointer")
+		set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -fomit-frame-pointer")
+		if(CMAKE_SYSTEM_NAME STREQUAL "Linux"
+				AND CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
+				AND CMAKE_CXX_COMPILER_VERSION MATCHES "^9\\.")
+			# Clang 9 has broken -ffast-math on glibc
+		else()
+			set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffast-math")
+		endif()
 	endif(CMAKE_SYSTEM_NAME MATCHES "(Darwin|BSD|DragonFly)")
 	set(CMAKE_CXX_FLAGS_SEMIDEBUG "-g -O1 -Wall -Wabi ${WARNING_FLAGS} ${OTHER_FLAGS}")
 	set(CMAKE_CXX_FLAGS_DEBUG "-g -O0 -Wall -Wabi ${WARNING_FLAGS} ${OTHER_FLAGS}")