WINEDBG(1)

NAME
winedbg - Wine debugger

SYNOPSIS
winedbg [ options ] [ program_name [ program_arguments ] | wpid ]

winedbg --gdb [ options ] [ program_name [ program_arguments ] | wpid ]

winedbg --auto wpid

winedbg --minidump [ file.mdmp ] wpid

winedbg file.mdmp

DESCRIPTION
winedbg is a debugger for Wine. It allows:
    - debugging native Win32 applications
    - debugging Winelib applications
    - being a drop-in replacement for Dr Watson

MODES
winedbg can be used in five modes. The first argument to the program determines the mode winedbg will run in.

default
    Without any explicit mode, this is standard winedbg operating mode. winedbg will act as the front end for the user.

--gdb
    winedbg will be used as a proxy for gdb. gdb will be the front end for command handling, and winedbg will proxy all debugging requests from gdb to the Win32 APIs.

--auto
    This mode is used when winedbg is set up in AeDebug registry entry as the default debugger. winedbg will then display basic information about a crash. This is useful for users who don't want to debug a crash, but rather gather relevant information about the crash to be sent to developers.

--minidump
    This mode is similar to the --auto one, except that instead of printing the information on the screen (as --auto does), it's saved into a minidump file. The name of the file is either passed on the command line, or generated by WineDbg when none is given. This file could later on be reloaded into winedbg for further examination.

file.mdmp
    In this mode winedbg reloads the state of a debuggee which has been saved into a minidump file. See either the minidump command below, or the --minidump mode.

OPTIONS
When in default mode, the following options are available:

--command string
    winedbg will execute the command string as if it was keyed on winedbg command line, and then will exit. This can be handy for getting the pid of running processes (winedbg --command "info proc").

--exec filename
    Sets the executable name, without starting the executable.

--file filename
    winedbg will execute the list of commands contained in file filename as if they were keyed on winedbg command line, and then will exit.

When in gdb proxy mode, the following options are available:

--no-start
    Don't launch gdb directly; instead, print the target remote GDB command to execute and listen for connection from any GDB-compatible debugger. Normally, --gdb will start both the proxy debugging server and an instance of gdb for the front end. This option instructs winedbg to skip launching of gdb, and instead prints the GDB command that can be used to manually connect to the server. This command is in the form

        target remote localhost:<port>

    where <port> is the TCP port winedbg's proxy debugging server is bound to.

    This option allows the user to replace gdb with some other debugger front end, such as ddd, kgdb, gdbgui, or Qt Creator. Regardless of whether --no-start is specified, winedbg will quit after the first connection is hung up (e.g. gdb detaches from the debuggee).

--port port
    Start the GDB proxy debugging server on the given port. If this option is not specified, winedbg will let the operating system choose any available port. This option can be used in conjunction with --no-start to specify the port the server shall be bound to.

--with-xterm
    This will run the gdb front end in a new xterm(1) window instead of using the current Unix terminal for its interface. This option is ignored if --no-start is specified.

In all modes, the rest of the command line, when passed, is used to identify which program, if any, is to be debugged:

program_name
    This is the name of an executable to start for a debugging session. winedbg will actually create a process with this executable. If program_arguments are also given, they will be used as arguments for creating the process to be debugged.

wpid
    winedbg will attach to the process whose Windows pid is wpid. Use the info proc command within winedbg to list running processes and their Windows pids.

default
    If nothing is specified, you will enter the debugger without any run nor attached process. You'll have to do the job yourself.

COMMANDS

  Default mode, and while reloading a minidump file:

Most of commands used in winedbg are similar to the ones from gdb. Please refer to the gdb documentations for some more details. See the gdb differences section later on to get a list of variations from gdb commands.

Misc. commands

abort
    Aborts the debugger.

quit
    Exits the debugger.

Process handling

attach N
    Attach to a Wine process (N is its Windows ID, numeric or hexadecimal). IDs can be obtained using the info process command. Note the info process command returns hexadecimal values

attach file.mdmp
    Reload the state of a debuggee from the minidump file.mdmp. See the minidump command to save such a file.

detach
    Detach the current Wine process. The process is no longer debugged by WineDbg, but is still running (for a live target).

kill
    Kills the current Wine process. The process is no longer debugged by WineDbg, and is also terminated (for a live target).

minidump file.mdmp
    Saves the debugging context of the debuggee into a minidump file called file.mdmp.

run Re-run the same process with the same arguments. Note: all breakpoints of precedent process are no longer available.

run arg1 arg2...
    Re-run the same process with arguments arg1 arg2.... Note: all breakpoints of precedent process are no longer available.

thread N
    Change the current thread to N (its Windows TID, numeric or hexadecimal).

Help commands

help
    Prints some help on the commands.

help info
    Prints some help on info commands

Flow control commands

cont
    Continue execution until next breakpoint or exception.

pass
    Pass the exception event up to the filter chain.

step
    Continue execution until next C line of code (enters function call)

next
    Continue execution until next C line of code (doesn't enter function call)

stepi
    Execute next assembly instruction (enters function call)

nexti
    Execute next assembly instruction (doesn't enter function call)

finish
    Execute until return of current function is reached.

cont, step, next, stepi, nexti can be postfixed by a number (N), meaning that the command must be executed N times before control is returned to the user.

Breakpoints, watchpoints

enable N
    Enables (break|watch)-point N

disable N
    Disables (break|watch)-point N

delete N
    Deletes (break|watch)-point N

cond N
    Removes any existing condition to (break|watch)-point N

cond N expr
    Adds condition expr to (break|watch)-point N. expr will be evaluated each time the (break|watch)-point is hit. If the result is a zero value, the breakpoint isn't triggered.

break * N
    Adds a breakpoint at address N

break id
    Adds a breakpoint at the address of symbol id

break id N
    Adds a breakpoint at the line N inside symbol id.

break N
    Adds a breakpoint at line N of current source file.

break
    Adds a breakpoint at current $PC address.

watch * N
    Adds a watch command (on write) at address N (on 4 bytes).

watch id
    Adds a watch command (on write) at the address of symbol id. Size depends on size of id.

rwatch * N
    Adds a watch command (on read) at address N (on 4 bytes).

rwatch id
    Adds a watch command (on read) at the address of symbol id. Size depends on size of id.

info break
    Lists all (break|watch)-points (with their state).

You can use the symbol EntryPoint to stand for the entry point of the Dll.

When setting a (break|watch)-point by id, if the symbol cannot be found (for example, the symbol is contained in a not yet loaded module), winedbg will recall the name of the symbol and will try to set the breakpoint each time a new module is loaded (until it succeeds).

Stack manipulation

bt  Print calling stack of current thread.

bt N
    Print calling stack of thread of ID N. Note: this doesn't change the position of the current frame as manipulated by the up & dn commands).

up  Goes up one frame in current thread's stack

up N
    Goes up N frames in current thread's stack

dn  Goes down one frame in current thread's stack

dn N
    Goes down N frames in current thread's stack

frame N
    Sets N as the current frame for current thread's stack.

info locals
    Prints information on local variables for current function frame.

Directory & source file manipulation

show dir
    Prints the list of dirs where source files are looked for.

dir pathname
    Adds pathname to the list of dirs where to look for source files

dir Deletes the list of dirs where to look for source files

symbolfile pathname
    Loads external symbol definition file pathname

symbolfile pathname N
    Loads external symbol definition file pathname (applying an offset of N to addresses)

list
    Lists 10 source lines forwards from current position.

list -
    Lists 10 source lines backwards from current position

list N
    Lists 10 source lines from line N in current file

list pathname:N
    Lists 10 source lines from line N in file pathname

list id
    Lists 10 source lines of function id

list * N
    Lists 10 source lines from address N

You can specify the end target (to change the 10 lines value) using the ',' separator. For example:

list 123, 234
    lists source lines from line 123 up to line 234 in current file

list foo.c:1,56
    lists source lines from line 1 up to 56 in file foo.c

Displaying

A display is an expression that's evaluated and printed after the execution of any winedbg command.

display

info display
    Lists the active displays

display expr
    Adds a display for expression expr

display /fmt expr
    Adds a display for expression expr. Printing evaluated expr is done using the given format (see print command for more on formats)

del display N

undisplay N
    Deletes display N

Disassembly

disas
    Disassemble from current position

disas expr
    Disassemble from address expr

disas expr,expr
    Disassembles code between addresses specified by the two expressions

Memory (reading, writing, typing)

x expr
    Examines memory at address expr

x /fmt expr
    Examines memory at address expr using format fmt

print expr
    Prints the value of expr (possibly using its type)

print /fmt expr
    Prints the value of expr (possibly using its type)

set var = expr
    Writes the value of expr in var variable

whatis expr
    Prints the C type of expression expr

fmt is either letter or count letter, where letter can be:

    s   an ASCII string

    u   a UTF16 Unicode string

    i   instructions (disassemble)

    x   32-bit unsigned hexadecimal integer

    d   32-bit signed decimal integer

    w   16-bit unsigned hexadecimal integer

    c   character (only printable 0x20-0x7f are actually printed)

    b   8-bit unsigned hexadecimal integer

    g   Win32 GUID

Expressions

Expressions in Wine Debugger are mostly written in a C form. However, there are a few discrepancies:

    Identifiers can take a '!' in their names. This allows mainly to specify a module where to look the ID from, e.g. USER32!CreateWindowExA.

    In a cast operation, when specifying a structure or a union, you must use the struct or union keyword (even if your program uses a typedef).

When specifying an identifier, if several symbols with this name exist, the debugger will prompt for the symbol you want to use. Pick up the one you want from its number.

Information on Wine internals

info class
    Lists all Windows classes registered in Wine

info class id
    Prints information on Windows class id

info share
    Lists all the dynamic libraries loaded in the debugged program (including .so files, NE and PE DLLs)

info share N
    Prints information on module at address N

info regs
    Prints the value of the CPU registers

info all-regs
    Prints the value of the CPU and Floating Point registers

info segment
    Lists all allocated segments (i386 only)

info segment N
    Prints information on segment N (i386 only)

info stack
    Prints the values on top of the stack

info map
    Lists all virtual mappings used by the debugged program

info map N
    Lists all virtual mappings used by the program of Windows pid N

info wnd
    Displays the window hierarchy starting from the desktop window

info wnd N
    Prints information of Window of handle N

info process
    Lists all w-processes in Wine session

info thread
    Lists all w-threads in Wine session

info frame
    Lists the exception frames (starting from current stack frame). You can also pass, as optional argument, a thread id (instead of current thread) to examine its exception frames.

Debug messages can be turned on and off as you are debugging using the set command, but only for channels initialized with the WINEDEBUG environment variable.

set warn + win
    Turns on warn on win channel

set + win
    Turns on warn/fixme/err/trace on win channel

set - win
    Turns off warn/fixme/err/trace on win channel

set fixme - all
    Turns off fixme class on all channels

  Gdb mode:

See the gdb documentation for all the gdb commands.

However, a few Wine extensions are available, through the monitor command:

monitor wnd
    Lists all windows in the Wine session

monitor proc
    Lists all processes in the Wine session

monitor mem
    Displays memory mapping of debugged process

  Auto and minidump modes:

Since no user input is possible, no commands are available.

ENVIRONMENT

WINE_GDB
    When used in gdb proxy mode, WINE_GDB specifies the name (and the path) of the executable to be used for gdb. "gdb" is used by default.

AUTHORS
The first version was written by Eric Youngdale.

See Wine developers list for the rest of contributors.

BUGS
Bugs can be reported on the Wine bug tracker (https://bugs.winehq.org).

AVAILABILITY
winedbg is part of the Wine distribution, which is available through WineHQ, the Wine development headquarters (https://www.winehq.org/).

SEE ALSO
wine(1),
Wine documentation and support (https://www.winehq.org/help).