From 73edc5aaba9ca0b269dc233af9f74755b68c5209 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 27 Jun 2020 19:20:31 +0100
Subject: [PATCH] CMake: Add ucontext on Mac/OSX

---
 CMakeLists.txt              |  2 ++
 cmake/FindMacUcontext.cmake | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 cmake/FindMacUcontext.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bde7183e7a..678a9fa8dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,6 +50,8 @@ if (APPLE)
     find_library(AUDIOTOOLBOX_LIBRARY AudioToolbox)
     find_library(AUDIOUNIT_LIBRARY AudioUnit)
     find_library(COCOA_LIBRARY Cocoa)
+
+    find_package(MacUcontext)
 endif (APPLE)
 
 if (MSVC)
diff --git a/cmake/FindMacUcontext.cmake b/cmake/FindMacUcontext.cmake
new file mode 100644
index 0000000000..4d989cd86a
--- /dev/null
+++ b/cmake/FindMacUcontext.cmake
@@ -0,0 +1,23 @@
+include(CheckCXXSourceCompiles)
+
+check_cxx_source_compiles("
+#include <sys/ucontext.h>
+int main() {
+    ucontext_t context;
+#if defined(__x86_64__)
+    void *ptr = (void *) context.uc_mcontext->__ss.__rip;
+#elif defined(__i386)
+    void *ptr = (void *) context.uc_mcontext->__ss.__rip;
+#else
+#error Unknown arch
+#endif
+    return 0;
+}"
+    UCONTEXT_FOUND
+)
+
+if (UCONTEXT_FOUND)
+    add_compile_options(
+        -DWITH_UCONTEXT
+    )
+endif (UCONTEXT_FOUND)