9.3   Debugging

Remote debugging is in most parts similar to “local” debugging. The procedure execution is controlled by execution commands (for example, Stop, Step Over, Step Into etc.). Debugging is only possible in stopped mode. If HDevEngine is in run mode, the status bar reads “Running... External application”, the following applies:

• No PC is displayed.
• Variables are uninitialized.
• Application threads cannot be selected, and the call stack is empty.

Independent of whether run or stop mode is active, the loaded procedures can be viewed in the program window. As usual, breakpoints may be set on program lines and variables. Activated breakpoints persist as long as the external application is running. In contrast, deactivated breakpoints disappear on disconnect. HDevEngine stops at breakpoints only if HDevelop is actually attached.

Pressing Stop causes HDevelop to wait for the external application to execute code in HDevEngine. In stop mode you can execute program lines step-by-step and view intermediate results in both the variable and the graphics window. Other than that, the execution cannot be influenced:

• The PC cannot be repositioned.
• The values of variables cannot be altered.
• The procedures cannot be reset.
• The program code cannot be modified (see also section “Limitations”).

If the application executes procedure calls in the GUI thread, attaching a debugger and stopping the execution will freeze the application GUI.