/Misc/gdbinit

  1# -*- ksh -*-
  2#
  3# If you use the GNU debugger gdb to debug the Python C runtime, you
  4# might find some of the following commands useful.  Copy this to your
  5# ~/.gdbinit file and it'll get loaded into gdb automatically when you
  6# start it up.  Then, at the gdb prompt you can do things like:
  7#
  8#    (gdb) pyo apyobjectptr
  9#    <module 'foobar' (built-in)>
 10#    refcounts: 1
 11#    address    : 84a7a2c
 12#    $1 = void
 13#    (gdb)
 14
 15# Prints a representation of the object to stderr, along with the
 16# number of reference counts it current has and the hex address the
 17# object is allocated at.  The argument must be a PyObject*
 18define pyo
 19print _PyObject_Dump($arg0)
 20end
 21
 22# Prints a representation of the object to stderr, along with the
 23# number of reference counts it current has and the hex address the
 24# object is allocated at.  The argument must be a PyGC_Head*
 25define pyg
 26print _PyGC_Dump($arg0)
 27end
 28
 29# print the local variables of the current frame
 30define pylocals
 31    set $_i = 0
 32    while $_i < f->f_nlocals
 33	if f->f_localsplus + $_i != 0
 34	    set $_names = co->co_varnames
 35	    set $_name = PyString_AsString(PyTuple_GetItem($_names, $_i))
 36	    printf "%s:\n", $_name
 37	    # side effect of calling _PyObject_Dump is to dump the object's
 38	    # info - assigning just prevents gdb from printing the
 39	    # NULL return value
 40	    set $_val = _PyObject_Dump(f->f_localsplus[$_i])
 41	end
 42        set $_i = $_i + 1
 43    end
 44end
 45
 46# A rewrite of the Python interpreter's line number calculator in GDB's
 47# command language
 48define lineno
 49    set $__continue = 1
 50    set $__co = f->f_code
 51    set $__lasti = f->f_lasti
 52    set $__sz = ((PyStringObject *)$__co->co_lnotab)->ob_size/2
 53    set $__p = (unsigned char *)((PyStringObject *)$__co->co_lnotab)->ob_sval
 54    set $__li = $__co->co_firstlineno
 55    set $__ad = 0
 56    while ($__sz-1 >= 0 && $__continue)
 57      set $__sz = $__sz - 1
 58      set $__ad = $__ad + *$__p
 59      set $__p = $__p + 1
 60      if ($__ad > $__lasti)
 61	set $__continue = 0
 62      end
 63      set $__li = $__li + *$__p
 64      set $__p = $__p + 1
 65    end
 66    printf "%d", $__li
 67end
 68
 69# print the current frame - verbose
 70define pyframev
 71    pyframe
 72    pylocals
 73end
 74
 75define pyframe
 76    set $__fn = (char *)((PyStringObject *)co->co_filename)->ob_sval
 77    set $__n = (char *)((PyStringObject *)co->co_name)->ob_sval
 78    printf "%s (", $__fn
 79    lineno
 80    printf "): %s\n", $__n
 81### Uncomment these lines when using from within Emacs/XEmacs so it will
 82### automatically track/display the current Python source line
 83#    printf "%c%c%s:", 032, 032, $__fn
 84#    lineno
 85#    printf ":1\n"
 86end
 87
 88### Use these at your own risk.  It appears that a bug in gdb causes it
 89### to crash in certain circumstances.
 90
 91#define up
 92#    up-silently 1
 93#    printframe
 94#end
 95
 96#define down
 97#    down-silently 1
 98#    printframe
 99#end
100
101define printframe
102    if $pc > PyEval_EvalFrameEx && $pc < PyEval_EvalCodeEx
103	pyframe
104    else
105        frame
106    end
107end
108
109# Here's a somewhat fragile way to print the entire Python stack from gdb.
110# It's fragile because the tests for the value of $pc depend on the layout
111# of specific functions in the C source code.
112
113# Explanation of while and if tests: We want to pop up the stack until we
114# land in Py_Main (this is probably an incorrect assumption in an embedded
115# interpreter, but the test can be extended by an interested party).  If
116# Py_Main <= $pc <= Py_GetArgcArv is true, $pc is in Py_Main(), so the while
117# tests succeeds as long as it's not true.  In a similar fashion the if
118# statement tests to see if we are in PyEval_EvalFrame().
119
120# print the entire Python call stack
121define pystack
122    while $pc < Py_Main || $pc > Py_GetArgcArgv
123        if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx
124	    pyframe
125        end
126        up-silently 1
127    end
128    select-frame 0
129end
130
131# print the entire Python call stack - verbose mode
132define pystackv
133    while $pc < Py_Main || $pc > Py_GetArgcArgv
134        if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx
135	    pyframev
136        end
137        up-silently 1
138    end
139    select-frame 0
140end
141
142# generally useful macro to print a Unicode string
143def pu
144  set $uni = $arg0 
145  set $i = 0
146  while (*$uni && $i++<100)
147    if (*$uni < 0x80) 
148      print *(char*)$uni++
149    else
150      print /x *(short*)$uni++
151    end
152  end
153end