(gdb.info) Breakpoints

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 Breakpoints, watchpoints, and catchpoints
 =========================================
 
    A "breakpoint" makes your program stop whenever a certain point in
 the program is reached.  For each breakpoint, you can add conditions to
 control in finer detail whether your program stops.  You can set
 breakpoints with the `break' command and its variants ( Setting
 breakpoints Set Breaks.), to specify the place where your program
 should stop by line number, function name or exact address in the
 program.
 
    In HP-UX, SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can
 set breakpoints in shared libraries before the executable is run.
 There is a minor limitation on HP-UX systems: you must wait until the
 executable is run in order to set breakpoints in shared library
 routines that are not called directly by the program (for example,
 routines that are arguments in a `pthread_create' call).
 
    A "watchpoint" is a special breakpoint that stops your program when
 the value of an expression changes.  You must use a different command
 to set watchpoints ( Setting watchpoints Set Watchpoints.), but
 aside from that, you can manage a watchpoint like any other breakpoint:
 you enable, disable, and delete both breakpoints and watchpoints using
 the same commands.
 
    You can arrange to have values from your program displayed
 automatically whenever GDB stops at a breakpoint.   Automatic
 display Auto Display.
 
    A "catchpoint" is another special breakpoint that stops your program
 when a certain kind of event occurs, such as the throwing of a C++
 exception or the loading of a library.  As with watchpoints, you use a
 different command to set a catchpoint ( Setting catchpoints Set
 Catchpoints.), but aside from that, you can manage a catchpoint like any
 other breakpoint.  (To stop when your program receives a signal, use the
 `handle' command; see  Signals Signals.)
 
    GDB assigns a number to each breakpoint, watchpoint, or catchpoint
 when you create it; these numbers are successive integers starting with
 one.  In many of the commands for controlling various features of
 breakpoints you use the breakpoint number to say which breakpoint you
 want to change.  Each breakpoint may be "enabled" or "disabled"; if
 disabled, it has no effect on your program until you enable it again.
 
    Some GDB commands accept a range of breakpoints on which to operate.
 A breakpoint range is either a single breakpoint number, like `5', or
 two such numbers, in increasing order, separated by a hyphen, like
 `5-7'.  When a breakpoint range is given to a command, all breakpoint
 in that range are operated on.
 

Menu

 
* Set Breaks                  Setting breakpoints
* Set Watchpoints             Setting watchpoints
* Set Catchpoints             Setting catchpoints
* Delete Breaks               Deleting breakpoints
* Disabling                   Disabling breakpoints
* Conditions                  Break conditions
* Break Commands              Breakpoint command lists
* Breakpoint Menus            Breakpoint menus
* Error in Breakpoints        ``Cannot insert breakpoints''
 

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