From bde2fa027ba61546b69f5b00ca3e3f154a50bce8 Mon Sep 17 00:00:00 2001
From: tbeu <tbeu@users.noreply.github.com>
Date: Sun, 19 Nov 2023 22:09:44 +0100
Subject: [PATCH] Add CMake option to link MSVC runtime library statically

---
 CMakeLists.txt           |  3 +++
 README                   |  2 ++
 README.md                |  2 ++
 cmake/options.cmake      | 16 ++++++++++++++++
 documentation/build.texi |  2 ++
 5 files changed, 25 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 745f549e..40ba4858 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,6 +3,9 @@ cmake_minimum_required(VERSION 3.7)
 if(POLICY CMP0074)
     cmake_policy(SET CMP0074 NEW)
 endif()
+if(POLICY CMP0091)
+    cmake_policy(SET CMP0091 NEW)
+endif()
 
 project(matio
     VERSION 1.5.26
diff --git a/README b/README
index c658d64b..4fc76cf6 100644
--- a/README
+++ b/README
@@ -191,6 +191,8 @@ Table of Contents
               * 'MATIO_SHARED:BOOL=ON'
                 This option builds the matio library as shared object
                 (i.e., a dynamic link library on Windows).
+              * 'MATIO_STATIC_LINK_CRT:BOOL=OFF'
+                This option links the MSVC runtime library statically.
               * 'MATIO_WITH_HDF5:BOOL=ON'
                 This option enables CMake to check for availability of the
                 HDF5 library (see section 2.1.2 for information about HDF5).
diff --git a/README.md b/README.md
index 3fd67660..1c57767f 100644
--- a/README.md
+++ b/README.md
@@ -132,6 +132,8 @@ This flag enables the support for version 7.3 MAT files.
 This option enables position-independent code (PIC), i.e., compilation with the `-fPIC` flag. It is ignored for Visual Studio builds.
 * `MATIO_SHARED:BOOL=ON`
 This option builds the matio library as shared object (i.e., a dynamic link library on Windows).
+* `MATIO_STATIC_LINK_CRT:BOOL=OFF`
+This option links the MSVC runtime library statically.
 * `MATIO_WITH_HDF5:BOOL=ON`
 This option enables CMake to check for availability of the HDF5 library (see section [2.1.2](#212-hdf5) for information about HDF5).
 * `MATIO_WITH_ZLIB:BOOL=ON`
diff --git a/cmake/options.cmake b/cmake/options.cmake
index f2e36459..f28ec42d 100644
--- a/cmake/options.cmake
+++ b/cmake/options.cmake
@@ -17,6 +17,22 @@ option(MATIO_SHARED "Build shared matio library, disable for static library" ON)
 # Option to enable position-independent code (PIC)
 option(MATIO_PIC "Enable position-independent code (PIC), i.e., compilation with the -fPIC flag" ON)
 
+# Option to link the MSVC runtime library statically
+option(MATIO_STATIC_LINK_CRT "Link the MSVC runtime library statically" OFF)
+
+if(POLICY CMP0091)
+    # CMake >= 3.15 has CMAKE_MSVC_RUNTIME_LIBRARY to set the MSVCC runtime library
+    if(WIN32 AND CMAKE_GENERATOR MATCHES "Visual Studio .*|NMake .*")
+        if(MATIO_STATIC_LINK_CRT)
+            message(STATUS "Configuring to link the MSVC runtime library statically")
+            set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+        else()
+            message(STATUS "Configuring to link the MSVC runtime library dynamically")
+            set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
+        endif()
+    endif()
+endif()
+
 # Build with hdf5 support
 option(MATIO_WITH_HDF5 "Check for HDF5 library" ON)
 
diff --git a/documentation/build.texi b/documentation/build.texi
index 1306bc62..63ec6565 100644
--- a/documentation/build.texi
+++ b/documentation/build.texi
@@ -103,6 +103,8 @@ Visual Studio builds.
 @item MATIO_SHARED:BOOL=ON
 This option builds the matio library as shared object
 (i.e., a dynamic link library on Windows).
+@item MATIO_STATIC_LINK_CRT:BOOL=OFF
+This option links the MSVC runtime library statically.
 @item MATIO_WITH_HDF5:BOOL=ON
 This option enables CMake to check for availability of the
 HDF5 library (see section 2.1.2 for information about HDF5).