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The WDB GUI offers two main views for looking at your code:
the Source view and the Disassembly view. Use the Source view to
see the contents of a file, and use the Disassembly view to see
the corresponding assembly code. The dwell feature allows you to quickly view the value of
a variable or expression. It is available from both the Source view
and Disassembly view. Viewing
source code | |
Before you can view your source code, you must have an executable
loaded and running in the WDB GUI. Once you have loaded a file,
you can use the Source view to see and manipulate your source code.
Specifically, you can use the Source view to: See the current
file’s source path. See the source file contents. See the current location
of the program counter. The program counter is set to the point
in your program where the debugger will begin executing. See the location and status
of breakpoints. See a stack marker that indicates
the current context, determined by the stack frame selected in the
Call Stack view. Access the pop-up menu to
perform actions that will affect how the code executes. Use dwell to quickly view
the value of a variable or expression.
To use
the pop-up menu in the Source ViewIn the Source view, click the right mouse button to display
a pop-up menu that contains the following commands: Enable/Disable Breakpoint
Viewing
assembly code | |
Before you can use the Disassembly view, your executable must
be running. You can use the Disassembly view to: See the assembly
code associated with the currently executing function. See the instruction that
corresponds to the current location of the program counter. The program
counter is set to the point in your program where the debugger will
begin executing. See the location and status
of breakpoints. See a stack marker that indicates
the current context, determined by the stack frame selected in the
Call Stack view. Access the pop-up menu to
perform actions that will affect how the code executes. Perform debug actions, such
as stepping through a program and setting breakpoints. Use dwell to quickly view
the value of a variable, register, or expression.
To view
code in the Disassembly ViewIn the main
window, click the Disassembly tab. View the assembly code content
in the right column of the Disassembly view. View the location of the
program counter, breakpoints, and the stack marker in the left column
of the Disassembly view.
To see
the Disassembly View in a separate windowClick the right
mouse button, then click Open Separate View. The separate window behaves
the same as the tabbed Disassembly view. To close the separate window,
click the right mouse button, then click Close.
To use
the pop-up menu in the Disassembly ViewIn the Disassembly view, click the right mouse button to display
a pop-up menu that contains the following commands: Enable/Disable Breakpoint
Viewing
variables using Dwell | |
The dwell feature displays the value of the variable or expression
on which the mouse pointer is paused. Dwell works in both the Source
view and the Disassembly view. Dwell gives you quick information about a variable. For more
detailed information, use Quick Watch, Watch view, or Local Variables
view. To view
the value of a variable or expressionUse the mouse
to position the pointer over a variable. For an expression (such
as a+b), highlight the expression to select it, then point to the
highlighted text. Do not move the pointer.
After a short time (about a half-second), a window appears that displays
the value of the variable or expression. Move the mouse or press a
key or button to close the dwell window. You can view the decimal
and hexadecimal value of a numeric variable or expression by changing
the preference in the Source View section of the Edit > Preferences
dialog box. See Setting Debugger Preferences. The displayed decimal
and hexadecimal values are separated by a semicolon(;)
Dwell does not display the value of certain types of variables
and expressions. It will not display the value of complex variables
such as arrays and structs, but it will display the value of elements
in an array, fields in a struct, and pointers. Expressions are not displayed if there may be a potential
side effect on the program being debugged (such as i++ or exit(1)).
Expressions containing ), =, ++, and -- are not displayed with dwell. Examples
of complex variablesDwell displays the value of fields as well as variables. Dwelling
on bar of foo->bar displays the value of foo->bar,
while dwelling on foo displays only the value of foo. In the expression a[i] there are several places to use dwell: If a is a pointer,
dwelling on a displays the value of variable a. If a is an array, dwelling
on a displays the text [...]. This indicates that the variable is
an array and cannot be viewed with dwell. You can use dwell to view
the value of individual elements within an array. Dwelling on i displays the
value of i. Dwelling on [ displays the
value of a[i].
In the expression *p, you can use dwell in the following ways: Dwelling on
the * displays the value of *p Dwelling on the p displays
the value of p
Use the function
browser to view source for a particular function. See Browsing Functions
for detais . Click the toolbar button
to open and close the Disassembly view in a separate window. On the View menu, click Source
or Disassembly to quickly bring that view to the top. You can customize the WDB
GUI to display line numbers in the Source view. On the Edit menu, click
Preferences and use the Display Line Numbers check box to set whether
line numbers are displayed in the Source view.
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