Using the Studio Debugger

Sample Debugging Session: Debugging a Routine

The following example demonstrates how to debug a routine.

1. Start Studio and select File > New Project to create a new project called Project1.

2. Create a new routine by selecting File > New > General tab > ObjectScript Routine.

3. Enter code for this routine:

   MyTest ; MyTest.MAC
   
   Main() PUBLIC {
       Set a = 10
       For i = 1:1:10 {
           Set b = i
                Write b," "
       }
   }
   

   

4. Save and compile the new routine as MyTest.MAC using File > Save As.

5. Define a debug target for the project by selecting the Debug > Debug Target tab, selecting Class Method or Routine, and entering the name of the entry point in your new routine, Main^MyTest.

6. Set a breakpoint in the routine: Position the cursor anywhere on the line Set a = 10 and press F9, the Toggle Breakpoint key. A breakpoint indicator appears in the left margin, .

7. Select Debug > Go to begin debugging. When the debugger stops at your breakpoint, the next command to be executed is outlined with a yellow box. The INT file opens in a new window. If the INT file does not open, make sure you have enabled the Keep Generated Source Code option. (Select Tools > Options, click Compiler > Flags & Optimization in the left-hand pane, and select Keep generated source code.)

8. Enter b and a in the Watch window (View > Watch) so that you can watch the values.

9. Step through execution of the program by repeatedly selecting Debug > Step Into (F11) and notice the b value change.

You can stop debugging by stepping to the end of the program or by selecting Debug > Stop.

Debugger Settings for the Current Project

Some debug settings are defined and stored in the current project. These include:

• Debug target

• Breakpoints

• Watchpoints

Debug Menu

Debug menu options are described below:

Menu Option	Action
Attach	Displays a list of processes currently running on the InterSystems server and lets you attach to one to debug. If you select a process and select OK, Studio breaks into the selected target process and allows you to start debugging it. If you generated source for the current routine executing in the target process, the source is displayed in an editor window. If you later terminate debugging with Debug > Stop, the target process resumes executing.
Go	If you are not currently debugging, Go starts the target specified by the Project's debug target. If you haven't set a target, you are asked for one. A debug target is the name of routine or method to execute; you can set this using the Debug Target dialog. Once the target is started, it runs until the first breakpoint. If you did not set any breakpoints in your application, it runs to completion without stopping.
Restart	Halts execution of the target process, restarts it, and resumes debugging (as if the Go command was used).
Stop	Stops debugging and either halts the target process or detaches from it. If the target process was running and attached to with Attach, then the target process continues running. If the target process was started as a result of the Go command, then it is terminated.
Break	Pauses execution of the target process (that is, if the debugger is attached to a target process that is currently running, not stopped).
Interrupt	Interrupts execution of the current command.
Step Into	Executes the current command in the target process and stops on the next command, stepping into any function calls or loop bodies.
Step Over	Executes the current command in the target process and stops on the next command. The debugger steps over any function calls or code blocks (such as loops) it encounters; it stops on the command following the function call or code block.
Step Out	Advances the execution of the target process by leaving or stepping out of the current code block or function and stops on the next command at this outer level.
Run To Cursor	Available only for documents containing INT routines. Starts execution of the target process and stops when it reaches the line on which the cursor is currently located. This is equivalent to setting a breakpoint at the current line in the editor window, executing the Go command, and clearing the breakpoint when the program halts.
Breakpoints	Toggle Breakpoints Sets or clears a breakpoint on the current line in the current document. View Breakpoints: Opens the Breakpoints dialog with which you can list, add, and remove breakpoints.
Debug Target	Enter a debug target – a method or routine. See also Debug Target.

Watch Window

The Watch Window displays a table in which you can watch the values of variables and simple expressions. All variables and expressions listed in the Watch Window are evaluated after each debugger operation (such as Step Over) and their resulting values are displayed in the second column of the Watch Window. If the value of a variable or expression changes after a debugger operation, it is displayed in red. If a variable in the watch list is undefined when it is evaluated, then the value is displayed as: <UNDEFINED>. Similarly, any expression whose result is an error displays an error message for its value. You can also see the value of a variable by hovering your mouse over the variable in the debugger.

To add a variable or expression to the Watch Window, double-click an empty cell in the first column and enter the variable or expression. Alternatively, you can use your mouse to highlight text in an editor window, drag it over an empty cell in the Watch Window and drop it. You can edit the contents of the Watch Window by double-clicking on a variable or expression and typing.

The following are examples of variables and expressions you could enter into the Watch Window:

• a

• a + 10

• a(10,10)

• $L(a)

• person.Name

You can also change the value of a variable in the target process by entering a new value in the Value column of the Watch Window.