Setting the MSVC runtime in CMake

Question

I'm following the instructions in the CMake FAQ entry "How can I build my MSVC application with a static runtime?" to centralize selection of the MSVC runtime for a bunch of nested CMake projects (they are pulled in as Git submodules and added to the master project using CMake's `find_package()` directive). So, I wrote this CMake macro: ``` macro(configure_msvc_runtime) if(MSVC) # Default to statically-linked runtime. if("${MSVC_RUNTIME}" STREQUAL "") set(MSVC_RUNTIME "static") endif() # Set compiler options. set(variables CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELEASE CMAKE_C_FLAGS_RELWITHDEBINFO CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELEASE CMAKE_CXX_FLAGS_RELWITHDEBINFO ) if(${MSVC_RUNTIME} STREQUAL "static") message(STATUS "MSVC -> forcing use of statically-linked runtime." ) foreach(variable ${variables}) if(${variable} MATCHES "/MD") string(REGEX REPLACE "/MD" "/MT" ${variable} "${${variable}}") endif() endforeach() else() message(S…

Accepted Answer

It seems all the while I was working on this, I forgot to remove the bad CMake configuration I'm trying to replace.

Further down the build script, I had left this little bugger:

```
set(CMAKE_CXX_FLAGS_DEBUG
  "/DWIN32 /D_WINDOWS /EHsc /WX /wd4355 /wd4251 /wd4250 /wd4996"
  CACHE STRING "Debug compiler flags" FORCE
)
```

Basically, I was overriding the results of by `configure_msvc_runtime()` macro with build flags that did not set the MSVC runtime.

Setting the MSVC runtime in CMake

Solution

Problem