title: How to get STATIC library default by CMake
body: <p>I have a project integrated bt third-party project. One of it use </p>
  
  <pre><code>add_library(json 
    dist/jsoncpp.cpp
    dist/json/json.h
    dist/json/json-forwards.h)
  </code></pre>
  
  <p>no <code>STATIC</code> or <code>SHARED</code> used. When I build it not as third-party library but build it directly, it will produce a static library. But when I integrated it as third-party, it will produce a shared library. This will cause an error like:</p>
  
  <pre><code>Linking CXX shared library ThirdParty\ozz-animation\src\animation\offline\tools\json\json_d.dll
  LINK : fatal error LNK1104: can't open the file “ThirdParty\ozz-animation\src\animation\offline\tools\json\json_d.lib”
  </code></pre>
  
  <p>I know adding <code>STATIC</code> to <code>add_library()</code> will fixed the problem. But I use <strong>git submodule</strong> to manage it.
  I don't want to fork the project and sync every time.</p>
  
  <p>Is there any way to make it be a static library in the upper-layer CMakeLists.txt?</p>