From eb2509aef9faa428112b5da0f4e5730962def7af Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Sun, 7 Jul 2019 13:01:38 +0200
Subject: [PATCH] build: fix GetCompileFlags for CMake #10444

Ref: https://github.com/neovim/neovim/pull/10363#issuecomment-508916959
---
 cmake/GetCompileFlags.cmake | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/cmake/GetCompileFlags.cmake b/cmake/GetCompileFlags.cmake
index 77a5260780..482eacca16 100644
--- a/cmake/GetCompileFlags.cmake
+++ b/cmake/GetCompileFlags.cmake
@@ -1,6 +1,6 @@
 function(get_compile_flags _compile_flags)
   # Create template akin to CMAKE_C_COMPILE_OBJECT.
-  set(compile_flags "<CMAKE_C_COMPILER> <CFLAGS> <BUILD_TYPE_CFLAGS> <COMPILE_OPTIONS> <COMPILE_DEFINITIONS> <INCLUDES>")
+  set(compile_flags "<CMAKE_C_COMPILER> <CFLAGS> <BUILD_TYPE_CFLAGS> <COMPILE_OPTIONS><COMPILE_DEFINITIONS> <INCLUDES>")
 
   # Get C compiler.
   string(REPLACE
@@ -13,9 +13,11 @@ function(get_compile_flags _compile_flags)
   get_directory_property(compile_definitions
     DIRECTORY "src/nvim"
     COMPILE_DEFINITIONS)
-  # NOTE: list(JOIN) requires CMake 3.12.
+  # NOTE: list(JOIN) requires CMake 3.12, string(CONCAT) requires CMake 3.
   string(REPLACE ";" " -D" compile_definitions "${compile_definitions}")
-  string(CONCAT compile_definitions "-D" "${compile_definitions}")
+  if(compile_definitions)
+    set(compile_definitions " -D${compile_definitions}")
+  endif()
   string(REPLACE
     "<COMPILE_DEFINITIONS>"
     "${compile_definitions}"