Update cmake to 3.16 and add OPUS_STATIC_RUNTIME option to control MSVC runtime library choice.

Signed-off-by: Jean-Marc Valin <jmvalin@jmvalin.ca>

Author: Malcolmnixon

.github/workflows/cmake.yml

@@ -4,17 +4,17 @@ on: [push, pull_request]
 
 jobs:
   CMakeVersionTest:
-    name: Test build with CMake 3.1.0
+    name: Test build with CMake 3.16.0
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
       - name: Download models
         run: ./autogen.sh
-      - name: Install CMake 3.1
+      - name: Install CMake 3.16
         run: |
-          curl -sL https://github.com/Kitware/CMake/releases/download/v3.1.0/cmake-3.1.0-Linux-x86_64.sh -o cmakeinstall.sh
+          curl -sL https://github.com/Kitware/CMake/releases/download/v3.16.0/cmake-3.16.0-Linux-x86_64.sh -o cmakeinstall.sh
           chmod +x cmakeinstall.sh
           sudo ./cmakeinstall.sh --prefix=/usr/local --exclude-subdir
           rm cmakeinstall.sh

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.16)
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 include(OpusPackageVersion)
@@ -97,6 +97,12 @@ if(APPLE)
   add_feature_info(OPUS_BUILD_FRAMEWORK OPUS_BUILD_FRAMEWORK ${OPUS_BUILD_FRAMEWORK_HELP_STR})
 endif()
 
+if(MSVC)
+  set(OPUS_STATIC_RUNTIME_HELP_STR "build with static runtime library.")
+  option(OPUS_STATIC_RUNTIME ${OPUS_STATIC_RUNTIME_HELP_STR} OFF)
+  add_feature_info(OPUS_STATIC_RUNTIME OPUS_STATIC_RUNTIME ${OPUS_STATIC_RUNTIME_HELP_STR})
+endif()
+
 set(OPUS_FIXED_POINT_DEBUG_HELP_STR "debug fixed-point implementation.")
 cmake_dependent_option(OPUS_FIXED_POINT_DEBUG
                       ${OPUS_FIXED_POINT_DEBUG_HELP_STR}
@@ -265,6 +271,14 @@ if(OPUS_CUSTOM_MODES)
   list(APPEND Opus_PUBLIC_HEADER ${CMAKE_CURRENT_SOURCE_DIR}/include/opus_custom.h)
 endif()
 
+if(MSVC)
+  if(OPUS_STATIC_RUNTIME)
+    set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+  else()
+    set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
+  endif()
+endif()
+
 add_library(opus ${opus_headers} ${opus_sources} ${opus_sources_float} ${Opus_PUBLIC_HEADER})
 add_library(Opus::opus ALIAS opus)