How do I add a watch point in GDB?
If GDB cannot set a hardware watchpoint, it sets a software watchpoint, which executes more slowly and reports the change in value at the next statement, not the instruction, after the change occurs. You can force GDB to use only software watchpoints with the set can-use-hw-watchpoints 0 command.
What does GDB’s watch command do?
Able to set a watchpoint on a variable in order to break a program when a variable changes. Use display to automatically print how variables change throughout the program’s execution. watch allows us to stop the execution every time the value of a variable changes.
What GDB command shows the contents of the current stack frame?
info frame displays information about the current stack frame. info locals displays the list of local variables and their values for the current stack frame, and info args displays the list of arguments.
How do you put a watch point on?
Steps:
- Set a debugging point at the loop statement of the internal table, once the debugging screen appears then press F5, an entry would appear in the workarea “LS_MARA”.
- Now keep the cursor on the field to which we want to set the watchpoint.
What is watch point debugging?
In SAP, a watchpoint is a conditional breakpoint that is only defined in the ABAP Debugger. It is one of the runtime utility components provided to debug SAP application programs and serves as an indicator to the ABAP runtime processor to interrupt further program processing from the specified point or relation.
How can I constantly watch variables in gdb?
If you want a graphical version of GDB, then you can look at DDD. It has the exact option you’re looking for. GDB – not being graphical – cannot deliver the kind of functionality in a pane, but you can use the display command to show a variable after each step.
What happens when a variable goes out of scope in gdb?
To recreate the watchpoint if the variable it is watching goes out of scope, have gdb do this automatically using a breakpoint at the start of the function as Zan has described. You can set a watchpoint that does not go out of scope by setting it to the memory address. This also works for other data types and pointers.
When does GDB break when the value of expr changes?
GDB will break when the expression expr is written into by the program and its value changes. The simplest (and the most popular) use of this command is to watch the value of a single variable: If the command includes a [thread thread-id] argument, GDB breaks only when the thread identified by thread-id changes the value of expr.
How to set conditional breakpoints in gdb 6.8?
My gdb is GNU gdb 6.8-debian. I agree with Dave that a conditional breakpoint is the way to go. However, to do what you asked, you can use GDB’s commands command to set a list of GDB commands to execute whenever a breakpoint is hit. I find this incredibly useful.