From 9732a2d99f695e15b083839ab224bf799884052f Mon Sep 17 00:00:00 2001
From: Maarten Bent <MaartenBent@users.noreply.github.com>
Date: Tue, 4 Jun 2019 22:49:22 +0200
Subject: [PATCH] CMake: Allow to toggle between static and dynamic MSVC
 runtime

After enabling wxBUILD_USE_STATIC_RUNTIME it cannot be disabled again
(except by manually modifying CMAKE_C*_FLAGS_*). Improve this by setting
the build flags to their default value when wxBUILD_USE_STATIC_RUNTIME
is disabled.

Closes https://github.com/wxWidgets/wxWidgets/pull/1338
---
 build/cmake/init.cmake | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/build/cmake/init.cmake b/build/cmake/init.cmake
index 0c320ae1d7..1b6604deef 100644
--- a/build/cmake/init.cmake
+++ b/build/cmake/init.cmake
@@ -8,7 +8,14 @@
 # Licence:     wxWindows licence
 #############################################################################
 
-if(DEFINED wxBUILD_USE_STATIC_RUNTIME AND wxBUILD_USE_STATIC_RUNTIME)
+if(MSVC)
+    # Determine MSVC runtime library flag
+    set(MSVC_LIB_USE "/MD")
+    set(MSVC_LIB_REPLACE "/MT")
+    if(wxBUILD_USE_STATIC_RUNTIME)
+        set(MSVC_LIB_USE "/MT")
+        set(MSVC_LIB_REPLACE "/MD")
+    endif()
     # Set MSVC runtime flags for all configurations
     foreach(cfg "" ${CMAKE_CONFIGURATION_TYPES})
         set(c_flag_var CMAKE_C_FLAGS)
@@ -18,13 +25,13 @@ if(DEFINED wxBUILD_USE_STATIC_RUNTIME AND wxBUILD_USE_STATIC_RUNTIME)
             wx_string_append(c_flag_var "_${cfg_upper}")
             wx_string_append(cxx_flag_var "_${cfg_upper}")
         endif()
-        if(${c_flag_var} MATCHES "/MD")
-            string(REPLACE "/MD" "/MT" ${c_flag_var} "${${c_flag_var}}")
+        if(${c_flag_var} MATCHES ${MSVC_LIB_REPLACE})
+            string(REPLACE ${MSVC_LIB_REPLACE} ${MSVC_LIB_USE} ${c_flag_var} "${${c_flag_var}}")
             set(${c_flag_var} ${${c_flag_var}} CACHE STRING
               "Flags used by the C compiler during ${cfg_upper} builds." FORCE)
         endif()
-        if(${cxx_flag_var} MATCHES "/MD")
-            string(REPLACE "/MD" "/MT" ${cxx_flag_var} "${${cxx_flag_var}}")
+        if(${cxx_flag_var} MATCHES ${MSVC_LIB_REPLACE})
+            string(REPLACE ${MSVC_LIB_REPLACE} ${MSVC_LIB_USE} ${cxx_flag_var} "${${cxx_flag_var}}")
             set(${cxx_flag_var} ${${cxx_flag_var}} CACHE STRING
               "Flags used by the CXX compiler during ${cfg_upper} builds." FORCE)
         endif()