{"id":1443,"date":"2013-06-26T15:20:00","date_gmt":"2013-06-26T15:20:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vcblog\/2013\/06\/26\/just-my-code-for-c-in-vs-2013\/"},"modified":"2021-09-29T14:13:10","modified_gmt":"2021-09-29T14:13:10","slug":"just-my-code-for-c-in-vs-2013","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/cppblog\/just-my-code-for-c-in-vs-2013\/","title":{"rendered":"Just My Code for C++ in VS 2013"},"content":{"rendered":"

If you have experience debugging C# or Visual Basic code in Visual Studio, you are probably familiar with a debugging feature called Just My Code (JMC).  <\/span>In Visual Studio 2013, we introduce Just My Code for C++.  <\/span>In VS2013, the goal of this C++ JMC feature is to help the user focus on their code when viewing call stacks without getting lost in library code, Windows code, etc.<\/span> <\/span><\/span><\/p>\n

User Experience<\/span><\/span><\/span><\/p>\n

When looking at a call stack, the debugger will collapse all consecutive frames of non-user code into an annotated frame labeled [External Code].  <\/span>There is an exception to this, if the application is stopped in non-user code, then external code at the top part of the call stack will be shown. <\/span><\/span><\/span><\/p>\n

Let’s start with the most basic example.  <\/span>If you create a new Win32 Console application in Visual Studio 2012 (or in VS2013 with JMC turned off) and set a breakpoint on the first line, you will get the following call stack:<\/span><\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 To most users, only the top frame is really the only part that is interesting.  <\/span>The Just My Code feature reduces the call stack to this:<\/span><\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 Just My Code does not just apply to the Call Stack window, but to anywhere call stacks are shown.  <\/span>For example, you get these same benefits in the Threads window:<\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 <\/span>Or in the Parallel Stacks window:<\/span> <\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

JMC can be extremely helpful in cases where there is a lot of library code that makes it difficult to find your own code.  <\/span>Consider this example when debugging a Windos Store app.  The call stack is so unwieldy that you can’t see the user code you care about even when you un-dock the Call Stack window and expand it to its near maximum size.<\/span> <\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

Just My Code makes it much simpler to find your code so that you can navigate to it.<\/span><\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 <\/p>\n

Turning JMC off and on<\/span><\/span><\/span><\/p>\n

If it turns out that if you do want to see the external code, you can use the context menu in the call stack window to toggle between showing and hiding external code.<\/span><\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 When you turn this off, Just My Code will display the external call stack frames in a lighter gray color.<\/span><\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 <\/span>If you want to turn Just My Code off completely, you can change the setting in Tools->Options.<\/span> <\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

 Customizing Non-user code<\/span><\/span><\/span><\/p>\n

 While there is a default experience for JMC out of the box, you can further customize it to your liking if you so choose.  <\/span>Non-user code is defined in xml files with a .natjmc extension found in one of two locations. <\/span><\/span><\/span><\/p>\n

 %VSINSTALLDIR%\\Common7\\Packages\\Debugger\\Visualizers <\/span><\/span><\/p>\n

 %USERPROFILE%\\My Documents\\Visual Studio 2012\\Visualizers <\/span><\/span><\/p>\n

 These are the same locations that are used when processing native visualizers (natvis files<\/span><\/a><\/ins><\/span>). The default is settings are found in %VSINSTALLDIR%\\Common7\\Packages\\Debugger\\Visualizers\\default.natjmc and provide a full illustrative example of how code is defined as non-user.<\/span><\/span><\/p>\n

\"Image<\/a><\/p>\n

As you can see, you can define code as non-user on three different levels:<\/span><\/span><\/p>\n