From f3af3d1c14afe6c4cb0f1957a82de837d1ff588e Mon Sep 17 00:00:00 2001
From: Joe Drago <jdrago@netflix.com>
Date: Sun, 1 Nov 2020 18:16:27 -0800
Subject: [PATCH] Fix clang build on macOS

---
 CMakeLists.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 97e373f..603ed29 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -85,6 +85,12 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     -Wno-switch-enum
     -Wno-undef
   )
+  # The detection of cross compilation by -Wpoison-system-directories has false positives on macOS because
+  # --sysroot is implicitly added. Turn the warning off.
+  check_c_compiler_flag(-Wpoison-system-directories HAVE_POISON_SYSTEM_DIRECTORIES_WARNING)
+  if(HAVE_POISON_SYSTEM_DIRECTORIES_WARNING)
+      add_definitions(-Wno-poison-system-directories)
+  endif()
 elseif(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
   add_definitions(-std=c99) # Enforce C99 for gcc
   MESSAGE(STATUS "Enabling warnings (for colorist lib/bin) for GCC")