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21.1.5 Features for Debugging MS Windows PE Executables

gdb supports native debugging of MS Windows programs, including DLLs with and without symbolic debugging information.

MS-Windows programs that call SetConsoleMode to switch off the special meaning of the ‘Ctrl-C’ keystroke cannot be interrupted by typing C-c. For this reason, gdb on MS-Windows supports C-<BREAK> as an alternative interrupt key sequence, which can be used to interrupt the debuggee even if it ignores C-c.

There are various additional Cygwin-specific commands, described in this section. Working with DLLs that have no debugging symbols is described in Non-debug DLL Symbols.

info w32
This is a prefix of MS Windows-specific commands which print information about the target system and important OS structures.
info w32 selector
This command displays information returned by the Win32 API GetThreadSelectorEntry function. It takes an optional argument that is evaluated to a long value to give the information about this given selector. Without argument, this command displays information about the six segment registers.
info w32 thread-information-block
This command displays thread specific information stored in the Thread Information Block (readable on the X86 CPU family using $fs selector for 32-bit programs and $gs for 64-bit programs).


info dll
This is a Cygwin-specific alias of info shared.


dll-symbols
This command is deprecated and will be removed in future versions of gdb. Use the sharedlibrary command instead.

This command loads symbols from a dll similarly to add-sym command but without the need to specify a base address.


set cygwin-exceptions mode
If mode is on, gdb will break on exceptions that happen inside the Cygwin DLL. If mode is off, gdb will delay recognition of exceptions, and may ignore some exceptions which seem to be caused by internal Cygwin DLL “bookkeeping”. This option is meant primarily for debugging the Cygwin DLL itself; the default value is off to avoid annoying gdb users with false SIGSEGV signals.


show cygwin-exceptions
Displays whether gdb will break on exceptions that happen inside the Cygwin DLL itself.


set new-console mode
If mode is on the debuggee will be started in a new console on next start. If mode is off, the debuggee will be started in the same console as the debugger.


show new-console
Displays whether a new console is used when the debuggee is started.


set new-group mode
This boolean value controls whether the debuggee should start a new group or stay in the same group as the debugger. This affects the way the Windows OS handles ‘Ctrl-C’.


show new-group
Displays current value of new-group boolean.


set debugevents
This boolean value adds debug output concerning kernel events related to the debuggee seen by the debugger. This includes events that signal thread and process creation and exit, DLL loading and unloading, console interrupts, and debugging messages produced by the Windows OutputDebugString API call.


set debugexec
This boolean value adds debug output concerning execute events (such as resume thread) seen by the debugger.


set debugexceptions
This boolean value adds debug output concerning exceptions in the debuggee seen by the debugger.


set debugmemory
This boolean value adds debug output concerning debuggee memory reads and writes by the debugger.


set shell
This boolean values specifies whether the debuggee is called via a shell or directly (default value is on).


show shell
Displays if the debuggee will be started with a shell.