From c8b3ec17114ab0cd7f22b23ab576b1f8092d7b8a Mon Sep 17 00:00:00 2001
From: Azat Khuzhin <azat@libevent.org>
Date: Mon, 17 Dec 2018 21:31:54 +0300
Subject: [PATCH] cmake: support static runtime (MSVC)

Fixes: #737
(cherry picked from commit 246f44041e0782f728fa5ff2d39113005a1ab02d)
---
 CMakeLists.txt | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4c192262..854c7e9d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -221,6 +221,34 @@ else()
     message(FATAL_ERROR "${EVENT_LIBRARY_TYPE} is not supported")
 endif()
 
+if (${MSVC})
+    set(msvc_static_runtime OFF)
+    if ("${EVENT_LIBRARY_TYPE}" STREQUAL "STATIC")
+        set(msvc_static_runtime ON)
+    endif()
+
+    # For more info:
+    # - https://docs.microsoft.com/en-us/cpp/build/reference/md-mt-ld-use-run-time-library?view=vs-2017
+    # - https://gitlab.kitware.com/cmake/community/wikis/FAQ#how-can-i-build-my-msvc-application-with-a-static-runtime
+    option(EVENT__MSVC_STATIC_RUNTIME
+           "Link static runtime libraries"
+           ${msvc_static_runtime})
+
+    if (EVENT__MSVC_STATIC_RUNTIME)
+        foreach (flag_var
+                 CMAKE_C_FLAGS
+                 CMAKE_C_FLAGS_DEBUG
+                 CMAKE_C_FLAGS_RELEASE
+                 CMAKE_C_FLAGS_MINSIZEREL
+                 CMAKE_C_FLAGS_RELWITHDEBINFO
+        )
+            if (${flag_var} MATCHES "/MD")
+                string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
+            endif()
+        endforeach()
+    endif()
+endif()
+
 # GNUC specific options.
 if (${GNUC})
     option(EVENT__DISABLE_GCC_WARNINGS "Disable verbose warnings with GCC" OFF)