You can debug shared libraries that
are either implicitly or explicitly loaded by your program. Implicitly
loaded shared libraries are libraries that your program is linked
against. Explicitly loaded shared libraries are loaded by calls
within your program to shl_load (3X).
(On Solaris systems, shared libraries are loaded by calls to dlopen(3X).)
To debug shared libraries, you must compile your main program
debuggable (with the -g
option). A main program compiled without -g
does not have enough information about shared libraries to allow
you to debug them, even if the libraries were compiled with -g.
If the shared library you want to debug was compiled with
-g, you can use
full source-level debugging. If it was not compiled with -g,
you must debug at the assembly level; but you can step into library
routines, set breakpoints in the routines, and refer to symbols
in the library.
The basic steps in debugging a shared library, and the debugger
commands that accomplish these, are as follows:
Make the library writable
using the property flags tgt_shlib_debug
command. This command is issued by default when you invoke the debugger,
but you can turn it off if you wish.
Intercept the loading of a library using the intercept load
command. This command is required only if you want the debugger
to stop at the loading of an explicitly loaded shared library. You
can use Execution: Signals/Intercepts
to perform this action.
Load the library. You do not need to issue a command
to do this. An implicitly loaded shared library is loaded at program
startup. An explicitly loaded shared library is loaded by a shl_load(3X)
call.
Load debugging information for the library using
the property libraries
command. You can issue this command before or after the library
itself is loaded.
The Dynamic Images dialog box also allows you to perform this
action. Invoke it by selecting Execution:Enable Images/Libraries.
Load alternate debugging information for a program
or library that has been compiled partly with and partly without
debugging information, so that you can debug the routines compiled
without debugging information (initialize -altdbinfo).
In this unusual situation, you must issue the initialize
command after the library is loaded.
You may also find the following command useful:
- list images
This command gives you a list of the shared libraries
your program uses. Use list images -full
to find out whether these libraries are mapped writable. The Execution:Enable Images/Libraries
dialog box also allows you to perform this action.
See the online help for more information and examples on debugging
shared libraries.
