# -*- ksh -*-

#

# If you use the GNU debugger gdb to debug the Python C runtime, you

# might find some of the following commands useful.  Copy this to your

# ~/.gdbinit file and it'll get loaded into gdb automatically when you

# start it up.  Then, at the gdb prompt you can do things like:

#

#    (gdb) pyo apyobjectptr

#    <module 'foobar' (built-in)>

#    refcounts: 1

#    address    : 84a7a2c

#    $1 = void

#    (gdb)

# Prints a representation of the object to stderr, along with the

# number of reference counts it current has and the hex address the

# object is allocated at.  The argument must be a PyObject*

define pyo

print _PyObject_Dump($arg0)

end

# Prints a representation of the object to stderr, along with the

# number of reference counts it current has and the hex address the

# object is allocated at.  The argument must be a PyGC_Head*

define pyg

print _PyGC_Dump($arg0)

end

# print the local variables of the current frame

define pylocals

    set $_i = 0

    while $_i < f->f_nlocals

	if f->f_localsplus + $_i != 0

	    set $_names = co->co_varnames

	    set $_name = PyString_AsString(PyTuple_GetItem($_names, $_i))

	    printf "%s:\n", $_name

	    # side effect of calling _PyObject_Dump is to dump the object's

	    # info - assigning just prevents gdb from printing the

	    # NULL return value

	    set $_val = _PyObject_Dump(f->f_localsplus[$_i])

	end

        set $_i = $_i + 1

    end

end

# A rewrite of the Python interpreter's line number calculator in GDB's

# command language

define lineno

    set $__continue = 1

    set $__co = f->f_code

    set $__lasti = f->f_lasti

    set $__sz = ((PyStringObject *)$__co->co_lnotab)->ob_size/2

    set $__p = (unsigned char *)((PyStringObject *)$__co->co_lnotab)->ob_sval

    set $__li = $__co->co_firstlineno

    set $__ad = 0

    while ($__sz-1 >= 0 && $__continue)

      set $__sz = $__sz - 1

      set $__ad = $__ad + *$__p

      set $__p = $__p + 1

      if ($__ad > $__lasti)

	set $__continue = 0

      end

      set $__li = $__li + *$__p

      set $__p = $__p + 1

    end

    printf "%d", $__li

end

# print the current frame - verbose

define pyframev

    pyframe

    pylocals

end

define pyframe

    set $__fn = (char *)((PyStringObject *)co->co_filename)->ob_sval

    set $__n = (char *)((PyStringObject *)co->co_name)->ob_sval

    printf "%s (", $__fn

    lineno

    printf "): %s\n", $__n

### Uncomment these lines when using from within Emacs/XEmacs so it will

### automatically track/display the current Python source line

#    printf "%c%c%s:", 032, 032, $__fn

#    lineno

#    printf ":1\n"

end

### Use these at your own risk.  It appears that a bug in gdb causes it

### to crash in certain circumstances.

#define up

#    up-silently 1

#    printframe

#end

#define down

#    down-silently 1

#    printframe

#end

define printframe

    if $pc > PyEval_EvalFrameEx && $pc < PyEval_EvalCodeEx

	pyframe

    else

        frame

    end

end

# Here's a somewhat fragile way to print the entire Python stack from gdb.

# It's fragile because the tests for the value of $pc depend on the layout

# of specific functions in the C source code.

# Explanation of while and if tests: We want to pop up the stack until we

# land in Py_Main (this is probably an incorrect assumption in an embedded

# interpreter, but the test can be extended by an interested party).  If

# Py_Main <= $pc <= Py_GetArgcArv is true, $pc is in Py_Main(), so the while

# tests succeeds as long as it's not true.  In a similar fashion the if

# statement tests to see if we are in PyEval_EvalFrame().

# print the entire Python call stack

define pystack

    while $pc < Py_Main || $pc > Py_GetArgcArgv

        if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx

	    pyframe

        end

        up-silently 1

    end

    select-frame 0

end

# print the entire Python call stack - verbose mode

define pystackv

    while $pc < Py_Main || $pc > Py_GetArgcArgv

        if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx

	    pyframev

        end

        up-silently 1

    end

    select-frame 0

end