Insight is a version of GDB that uses Tcl/Tk to implement a graphical
user inter-face. It is a fully integrated GUI, not a separate
front-end program. The interface consists of several separate
windows, which use standard elements like buttons, scrollbars, entry
boxes and such to create a fairly easy to use interface. Each window
has a distinct content and purpose, and can be enabled or disabled
individually. The windows contain things like the current source
file, a disassembly of the current function, text commands (for things
that aren't accessible via a button), and so forth.
Building Insight is very straightforward. It is configured/built by
default when you checkout or download Insight. Right now, Insight MUST
be built using the versions of Tcl, Tk, and Itcl that come with
the sources. We're working to fix that, but it is going to take a lot
of time. (Want to help?)
On Unix machines, you will also need to have X11 (R4/R5/R6) installed
(this is a prerequisite to installing Tk).
Insight inherits much of GDB's configuration options (like where it is
to be installed). See the GDB README file for more details on configure
options and such for GDB.
It is recommended that Insight, like GDB, be built outside of the source
directory in order to preserve the integrity of the source directory. This
is very useful, for example, when building GDB/Insight for multiple hosts
or targets.
For example:
host> ls
src/
host> mkdir insight; cd insight
host> ../src/configure
host> make
host> make install
Building insight for an embedded target is the same as building GDB for an embedded target.
You must pass options to configure to set up the build environment for the embedded taget in question.
Usually the only options you need to specify are --target and --prefix
--target specifies the embedded target to configure the build for. For example "powerpc-eabi".
--prefix specifies where you wish the built version of insight to install to. Usually you do not
want it to go to the default place, otherwise it will overwrite your native version of insight.
The following is an example for building for embedded powerpc:
host> ls
src/
host> mkdir insight-ppc; cd insight-pcc
host> ../src/configure --target=powerpc-eabi --prefix=/opt/insight-ppc
host> make
host> make install
There is no definitive list of targets supported by each version of GDB/Insight. The best place to look to find out
if your target is supported is in the configure script and the source tree of the particular version of insight
you are using.
During building, you may run into problems with finding Tcl, Tk or X11. Look
in gdb/Makefile, and fix TCL_CFLAGS, TCL, TK_CFLAGS, TK, and ENABLE_CLIBS as
appropriate.
If you one of the following messages when you run gdb:
Tcl_Init failed: can't find init.tcl; perhaps you need to
install Tcl or set your TCL_LIBRARY environment variable?
or
Tk_Init failed: can't find tk.tcl; perhaps you need to
install Tk or set your TK_LIBRARY environment variable?
then you haven't installed Tcl or TK properly. Fix the appropriate environment
variable to point at the {tcl tk}/library directory, and restart gdb.
You can start Insight by running the `insight' executable (for cross-platform
targets, include the build triple, i.e., `powerpc-elf-insight'). Alternatively start
Insight by telling GDB to start it with `gdb -w' or `gdb -i=insight'.
If everything goes well, you should have several windows pop up. To get going,
hit the Run button, and go exploring.
If you want to use GDB in command line mode, just use the -nw option or the
console interpreter (`insight -i=console').
Insight comes with all your standard debugger windows, including:
- Console Window
- Source Window
- Register Window
- Memory Window
- Locals Window
- Watch Window
- Stack Window
- Thread/Process Window
- Function Browser Window
- Debug Window (for developers)
Insight also has an extensive (if outdated) online help system which describes
all the windows and explains how to use them. Users are urged to browse this
help system for information on using Insight.
Insight and all of its support infrastructure read various environment variables
for optional startup information. All of these environment variables are
optional: Insight and its packages know how to find their files in both the
install and the source trees.
| Name
| Description
|
| TCL_LIBRARY | The location of the Tcl library files
|
| TK_LIBRARY | The location of the Tk library files
|
| TIX_LIBRARY | The location of the Tix library files
|
| REDHAT_GUI_LIBRARY | The location of the libgui library files
|
| GDBTK_LIBRARY | The location of the Insight library files
|
| INSIGHT_PLUGINS | A colon-separated list of directories to search for plugins (see gdb/gdbtk/plugins/HOW-TO)
|
| GDBTK_DEBUG | Controls runtime loading of the Debug Window. (This is the most useful debug option.)
|
| GDBTK_TRACE | Controls runtime tracing of the tcl code
|
| GDBTK_DEBUGFILE | Filename to send debug output
|
| GDBTK_TEST_RUNNING | Testsuite variable. See gdb/testsuite/gdb.gdbtk/README for more information.
|
| DISPLAY | The display to use on unix/X platforms. Not used on Windows platforms.
|
All of the environment variables for controlling Insight are well documented
in gdb/gdbtk/library/main.tcl. Search for "env" to find them all.
The GUI is primarily implemented by Tcl/Tk code which lives in gdb/gdbtk/library
and bunch of C files in gdb/gdbtk/generic. The Tcl/Tk code determines the look
and feel, the layout, and the functions associated with all of the interface
elements. The C code is mostly just glue between GDB internals and Tcl-land.
In essence, all of the policy is implemented in Tcl/Tk, and is easily changed
without recompiling.
To make more serious changes to the interface, such as adding a new window or
changing the framework, you will have to hack the tcl code (and probably the C
code as well). The tcl library install directory is $(libdir) (probably
/usr/local/lib/insight1.0). But, you will probably want to hack on your own
private copy before putting it up for the rest of the users. To find the GDB tcl
code, GDB first checks for the environment variable GDBTK_LIBRARY. GDB will check
this directory for the file "main.tcl". If GDBTK_LIBRARY is not set, GDB will
look for main.tcl in the install directory, and finally it will try to find
the tcl directory in the sources.
A word about the different files in Insight is in order. Insight is a hybrid of
C code and "Tcl" code (actuall Incr Tcl code). We use the following conventions
for naming our tcl files (most of the time!). Any file with a ".tcl" extension
is simply vanilla tcl code. Any file ending with ".itcl" is an Itcl file,
class definition and implementation all in one. So far so good. Now comes the
toughy: Files ending in ".ith" are Itcl class definition files, and they all
must have a corresponding implementation file, ending in ".itb". Why do we do
this? Simple. With Itcl, one can reread class implementations at runtime, but
one cannot change the class definition. So all those ".itcl" files can only
be reread be restarting Insight. The same is not true, though, of the ".itb"
files. Those files can be changed and immediately reread and used in Insight
without having to restart (as long as the class definition doesn't change). This
is a nifty Itcl feature which is fully exploited by the Debug Window, which
has a "ReSource" menu on it to reread the Tcl files. (To get to the Debug Window,
hit Ctrl-Alt-F11 in the Source Window or type "tk ManagedWin::open DebugWin" in
the Console Window.)
Internally, Insight is basically GDB, linked with Tcl/Tk, some Tcl/Tk extensions,
and some glue code that interfaces GDB internals to Tcl-land. This means that
Insight operates as a single program, not a front-end to GDB. All GDB commands,
and a great deal of the target program state are accessible to the Tcl programmer.
In addition, there are many callbacks from GDB to notify Tcl-land of important
events. Many of these are accomplished via "hooks" in GDB, and others are
accomplished using event notifications. GDB is slowly deprecating the use of
"hooks" in favor of its new event mechanism.
All of the below commands have lots of nice comments before them explaining what
they all do, how they are to be used, etc. The source code is the definitive
authority (other than a maintainer) for the definition/usage of a command in
Insight. Hackers are urged to read through the source code for any commands
which may need explaining.
New Tcl Commands:
Here is a brief, if incomplete (and possibly out of date), summary of the Tcl commands that are created
by Insight. These are installed into the Tcl interpreter in the C files.
| Name
| Description
|
| gdb_cmd | Sends a text command to gdb. Returns the result.
|
| | DEPRECATED: Do not use any more.
|
| gdb_loc | Returns a list of useful tidbits about the specified GDB linespec
|
| gdb_sourcelines | Returns a list of executable lines for a source file
|
| gdb_listfiles | Returns a list of all of the source files
|
| gdb_stop | Stops the target process (or at least tries to)
|
| gdb_reginfo | Returns information about registers (names, numbers, values, size, etc.)
|
| gdb_disassemble | Returns the text of a disassembly of the entire function. No longer used.
|
| gdb_load_disassembly | Loads the disassembly of a location into a source window's textbox
|
| gdb_eval | Returns the value of a given expression
|
| gdb_get_breakpoint_list | Returns a list of all breakpoints
|
| gdb_get_breakpoint_info | Returns a list of info about a breakpoint
|
Tcl procedures that are hooked into GDB:
This is a list, albeit incomplete (and possibly out of date), of the "hook" functions that are installed
into GDB. The actual "hooks" are installed/initialized in
gdb/gdbtk/generic/gdbtk-hooks.c (and maybe one or two in gdbtk.c). The list
below is the Tcl side of the hook.
| Name
| Description
|
| gdb_tcl_fputs | Sends output into Tcl for the command window
|
| gdb_tcl_query | Pops up a query window
|
| gdbtk_tcl_breakpoint | Notifies Tcl of changes to a breakpoint
|
| gdbtk_tcl_idle | Notifies Tcl that debugged process is now idle
|
| gdbtk_tcl_busy | Notifies Tcl that debugged process is now running
|
Events:
Starting with GDB 5.0, GDB has had an event loop. Although largely unused right
now, with it came some useful "baggage", especially event notifications, even
though they, too, were largely incomplete. The list of events continues to grow,
and Insight and GDB often "share" overlapping events, but the list below is
complete (since there are only a few defined events). The source for these
events can be found in gdb/gdbtk/library/gdbevents.it[hb].
| Name
| Description
|
| BreakpointEvent | A breakpoint has been created/modified/deleted
|
| TracepointEvent | A tracepoint has been created/modified/deleted
|
| SetVariableEvent | User has issued a "set" command in Console
|
| BusyEvent | The debugger is "busy"
|
| IdleEvent | The debugger is "idle"
|
| UpdateEvent | The state of the target has changed (or the GDB's view of the target has changed)
|
| ArchChangedEvent | The architecture of the system has changed (this can happen when GDB defaults to using
some basic CPU and detects that a more elaborate CPU is actually being used, e.g., SH5)
|
GDB Commands:
Insight installs a few GDB commands, which are available with the Console Window.
| Name
| Description
|
| tk | Executes the arguments in the Insight Tcl interpreter
|
| view | Displays the given linespec in the Source Window
|
TODO
- Rewrite any code with non FSF Copyright in Insight and assign to FSF.
- Get Insight integrated and accepted into the GDB mainline.
- Disassembly of code without symbolic information, allowing breakpoints to be set, etc.
- Setting Hardware Memory Watchpoints from memory window and/or variable watch window.
- Architecture sensitive visual editors/viewers for registers.
- Ability to view memory as a graphical bitmap (in a number of formats).
- Update/Expand Documentation.
- Update this FAQ
This Page is always under construction.
Have questions about the Insight GUI for the GDB debugger? Try
reading the README
or sending mail to
insight@sourceware.org.
Want to help with this FAQ or Web Site? Send email to the mailing list.
If you need help about Red Hat (Enterprise) Linux, please refer to
www.redhat.com
