cmake: Explicitly declare C as the project language

There's a mix of CXX and C related variables being set/referenced in our
CMake files.  Since we only use C, use an explicit language list of "C"
instead of the implicit "C CXX" and replace all uses of CXX variables
with their C counterparts

1 files changed, 4 insertions, 8 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 65490e4b6a..c97987e93f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,7 @@
 #   best practices (3.0+): https://gist.github.com/mbinna/c61dbb39bca0e4fb7d1f73b0d66a4fd1
 
 cmake_minimum_required(VERSION 2.8.7)
-project(nvim)
+project(nvim C)
 
 if(POLICY CMP0059)
   cmake_policy(SET CMP0059 OLD)  # Needed until cmake 2.8.12. #4389
@@ -47,9 +47,6 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
   if(CMAKE_COMPILER_IS_GNUCC)
     set(CMAKE_INCLUDE_SYSTEM_FLAG_C "-isystem ")
   endif()
-  if(CMAKE_COMPILER_IS_GNUCXX)
-    set(CMAKE_INCLUDE_SYSTEM_FLAG_CXX "-isystem ")
-  endif()
 endif()
 
 if(WIN32 OR CMAKE_SYSTEM_NAME STREQUAL "Darwin")
@@ -181,7 +178,6 @@ if(NOT HAS_ACCEPTABLE_FORTIFY)
   # -U in add_definitions doesn't end up in the correct spot, so we add it to
   # the flags variable instead.
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_FORTIFY_SOURCE_PREFIX}-U_FORTIFY_SOURCE ${_FORTIFY_SOURCE_PREFIX}-D_FORTIFY_SOURCE=1")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_FORTIFY_SOURCE_PREFIX}-U_FORTIFY_SOURCE ${_FORTIFY_SOURCE_PREFIX}-D_FORTIFY_SOURCE=1")
 endif()
 
 # Remove --sort-common from linker flags, as this seems to cause bugs (see #2641, #3374).
@@ -264,7 +260,7 @@ if(HAS_DIAG_COLOR_FLAG)
   add_definitions(-fdiagnostics-color=auto)
 endif()
 
-if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
   # 1. Array-bounds testing is broken in some GCC versions before 4.8.5.
   #    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273
   # 2. But _Pragma("...ignored") is broken (unresolved) in GCC 5+:
@@ -297,7 +293,7 @@ option(LOG_LIST_ACTIONS "Add list actions logging" OFF)
 
 add_definitions(-DINCLUDE_GENERATED_DECLARATIONS)
 
-if(CMAKE_COMPILER_IS_GNUCXX)
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "Clang")
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--no-undefined")
   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
   set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--no-undefined")
@@ -308,7 +304,7 @@ if(CMAKE_COMPILER_IS_GNUCXX)
   add_definitions(-D_GNU_SOURCE)
 endif()
 
-if(CMAKE_COMPILER_IS_GNUCXX AND CMAKE_SYSTEM_NAME STREQUAL "SunOS")
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU" AND CMAKE_SYSTEM_NAME STREQUAL "SunOS")
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--no-undefined -lsocket")
 endif()