title: IntelliSense in Visual Studio 2019 with CMake Project and IAR Compiler
body: <p>So I have a CMake project which I open in Visual Studio 2019 with the &quot;Open Folder&quot; option. From here I can build and compile it without any errors (CMake is using the IAR Compiler (iccarm.exe) as specified in the toolchain file). So far so good.
  The problem is that IntelliSense, despite finding all necessary header files, shows lots of errors mainly related to &quot;undefined __INTxx_T_TYPE__&quot;.</p>
  <p>As far as i know thouse double underscores indicate that it's a compiler internal data type, which is not defined in any header file, which would also explain why IntelliSense reports that it's not defined (even if the compiler knows the type). I guess to counter this problem, IntelliSense does support different modes like &quot;windows-msvc-x86&quot; or &quot;linux-gcc-arm&quot;. But there is no option for IAR compiler.</p>
  <p>So my question: How can I get IntelliSense running in this project ? Is there a way to add a custom IntelliSense mode for the IAR compiler ? Can i add header files only for IntelliSense in which the missing types are defined ? Is there a way to tell IntelliSense not to worry about those types / ignore the types ?</p>