# Simple python helper script to help printing gmp values within gdb.
#
# Emmanuel Thomé, 2013.
# This file is placed in the public domain
# Prerequisites:
# - gdb 7.2 or later.
# - gmpy2 bindings for python. On debian, this may mean either the
# python-gmpy2 or python3-gmpy2 package. Your mileage may vary on other
# systems. For a cross-system and realtively painless installation
# procedure, you may consider:
#
# easy_install --user gmpy2
#
# Usage: enable the pretty-printers of this file with the following gdb
# command:
#
# source /path/to/this/file/gdb-gmp.py
#
# It is also possible to place this very command in your gdb startup file
# $HOME/.gdbinit.
#
# The code here currently reacts on the types mpz, mpfr, mpc, mpfrx
# (defined in their respective libraries, but it does not hurt to
# pretty-print them all). Please do not hesitate to expand to other
# types, and contribute to this file.
#
# Big integers being sometimes big, there is a natural risk of filling up
# terminal space. Therefore, this script has a limit on the size of
# numbers displayed, set by default to 40 characters. Numbers above this
# limit are printed as follows:
#
# Breakpoint 1, foo (x=12, z=68812...<6642>...9205452) at toto.c:6
#
# The display limit may be updated from within gdb as follows:
#
# (gdb) python update_display_limit(200)
# Referene on python scripting:
# http://sourceware.org/gdb/current/onlinedocs/gdb/Python.html
# Prefer gdb 7.2 or later for this, because of the following bug (which
# bites you if you have mpz_t's in structs):
# http://comments.gmane.org/gmane.comp.gdb.patches/59238
# Otherwise gdb 7.1 will work.
import gdb
import string
from gmpy2 import mpz,mpfr
__all__=['update_display_limit', 'make_mp_printer_objects', 'hook_mp_printers', 'unhook_mp_printers' ]
try:
gdb.pretty_printers.remove(make_mp_printer_objects)
except NameError:
pass
except ValueError:
print("Caught ValueError, ignoring")
pass
# arrange so that at most 40 characters of each field are printed.
display_limit=40
def gmpy_from_mpn(d, nlimbs, wordsize):
res=mpz(0)
word=pow(mpz(2),wordsize)
for i in range(0,nlimbs):
a=mpz(int(d[nlimbs-1-i]))
# python ints are signed, beware.
if a < 0: a+=word
res=res*word+a
return res
def truncate_output(r):
# not completely satisfactory
if display_limit == 0:
return r
l=len(r)
if l >= display_limit:
r=r[0:display_limit-15] +"...<%d>..."%(l-(display_limit-12)) +r[l-7:l]
return r
def update_display_limit(l):
global display_limit
display_limit=l
class mpfr_printer:
def __init__(self, val):
self.val = val
def mantissa_exponent(self):
X = self.val
sign = int(X['_mpfr_sign'])
exp = int(X['_mpfr_exp'])
prec = int(X['_mpfr_prec'])
d = X['_mpfr_d']
wordsize=gdb.lookup_type("unsigned long").sizeof * 8
nlimbs=(prec+wordsize-1)/wordsize
# print "(via %s) Have prec %d, %d limbs\n" % (self.vt, prec,nlimbs)
# try:
mantissa=gmpy_from_mpn(d, nlimbs, wordsize)
mantissa*=sign
e=exp-nlimbs*wordsize
return mantissa, e
def to_string(self):
X = self.val
mantissa,e = self.mantissa_exponent()
prec = int(X['_mpfr_prec'])
exp = int(X['_mpfr_exp'])
wordsize=gdb.lookup_type("unsigned long").sizeof * 8
special=-pow(2,wordsize-1)
sign = int(X['_mpfr_sign'])
if exp == special+2:
return "NaN"
if exp == special+1:
if sign < 0:
return "-0"
else:
return "0"
if exp == special+3:
if sign < 0:
return "-inf"
else:
return "+inf"
res=mpfr(mantissa, prec)
if e>0: res*=pow(mpz(2),e)
else: res/=pow(mpz(2),-e)
return truncate_output(str(res))
class mpz_printer:
def __init__(self, val):
self.val = val
def to_string(self):
X = self.val
# There's apparently a bug in array member of structs. Their
# starting address seems to be constantly equal to the starting
# address of the struct itself...
# print "X at %s\n" % X.address
size = int(X['_mp_size'])
d = X['_mp_d']
wordsize=gdb.lookup_type("unsigned long").sizeof * 8
nlimbs=size
if size<0: nlimbs=-int(size)
# try:
mantissa=gmpy_from_mpn(d, nlimbs, wordsize)
# except RuntimeError:
# # it's not necessarily a good idea to do this.
# return "<error>"
if size<0: mantissa=-mantissa
return truncate_output(str(mantissa))
class mpq_printer:
def __init__(self, val):
self.num = mpz_printer(val['_mp_num'])
self.den = mpz_printer(val['_mp_den'])
def to_string(self):
d = self.den.to_string()
if d == "1":
return self.num.to_string()
else:
return self.num.to_string() + "/" + d
class mpz_mat_printer:
def __init__(self, val):
self.val = val
self.m = int(val['m'])
self.n = int(val['n'])
def to_string(self):
s = []
for i in range(self.m):
for j in range(self.n):
foo = mpz_printer(self.val['x'][i * self.n + j])
s.append(foo.to_string())
l=max([len(x) for x in s])
fmt = "%%-%ds" % l
out="\n"
for i in range(self.m):
for j in range(self.n):
if j > 0:
out += " "
out += (fmt % s[i * self.n + j])
out += "\n"
return out
class mpq_mat_printer:
def __init__(self, val):
self.val = val
self.m = int(val['m'])
self.n = int(val['n'])
def to_string(self):
s = []
for i in range(self.m):
for j in range(self.n):
foo = mpq_printer(self.val['x'][i * self.n + j])
s.append(foo.to_string())
l=max([len(x) for x in s])
fmt = "%%-%ds" % l
out="\n"
for i in range(self.m):
for j in range(self.n):
if j > 0:
out += " "
out += (fmt % s[i * self.n + j])
out += "\n"
return out
class mpc_printer:
def __init__(self, val):
# print val['re'].address
self.re = mpfr_printer(val['re'].dereference())
self.im = mpfr_printer(val['im'].dereference())
def to_string(self):
return self.re.to_string() + "+i*" + self.im.to_string()
class mpfrx_printer:
def __init__(self, val):
self.val = val
def to_string(self):
X = self.val
n=int(X['deg'])+1
coeffs=[mpfr_printer(X['coeff'][i]).to_string() for i in range(n)]
res="(%s %s)" % (n-1, " ".join(coeffs))
return res
def make_mp_printer_objects(val):
try:
# beware. If we hook on mpfr_t to remove the extra braces, then
# some bugs pop up -- apparently dereferencing this pointer does
# not work as it should in arrays of mpfr_t's. Haven't checked,
# but I assume it's similar for other types.
t=str(val.type)
# print("[request for %s]\n" % t)
if (t == 'mpz_ptr' or t == 'mpz_srcptr'):
return mpz_printer(val.dereference())
if (t == 'mpz_t' or t == '__mpz_struct [1]'):
return mpz_printer(val.dereference())
if (t == '__mpz_struct'):
return mpz_printer(val)
if (t == 'cxx_mpz'):
return mpz_printer(val['x'])
if (t == 'mpq_ptr' or t == 'mpq_srcptr'):
return mpq_printer(val.dereference())
if (t == 'mpq_t' or t == '__mpq_struct [1]'):
return mpq_printer(val.dereference())
if (t == '__mpq_struct'):
return mpq_printer(val)
if (t == 'cxx_mpq'):
return mpq_printer(val['x'])
if (t == 'mpfr_ptr' or t == 'mpfr_srcptr'):
return mpfr_printer(val.dereference())
if (t == 'mpfr_t' or t == '__mpfr_struct [1]'):
return mpfr_printer(val.dereference())
if (t == '__mpfr_struct'):
return mpfr_printer(val)
if (t == 'mpc_ptr' or t == 'mpc_srcptr'):
return mpc_printer(val.dereference())
if (t == 'mpc_t' or t == '__mpc_struct [1]'):
return mpc_printer(val.dereference())
if (t == '__mpc_struct'):
return mpc_printer(val)
if (t == 'mpfrx_ptr' or t == 'mpfrx_srcptr'):
return mpfrx_printer(val.dereference())
if (t == 'mpfrx_t' or t == '__mpfrx_struct [1]'):
return mpfrx_printer(val.dereference())
if (t == '__mpfrx_struct'):
return mpfrx_printer(val)
if (t == 'mpz_mat_ptr' or t == 'mpz_mat_srcptr'):
return mpz_mat_printer(val.dereference())
if (t == 'mpz_mat'):
return mpz_mat_printer(val.dereference())
if (t == 'mpz_mat_s'):
return mpz_mat_printer(val)
if (t == 'cxx_mpz_mat'):
return mpz_mat_printer(val['x'])
if (t == 'mpq_mat_ptr' or t == 'mpq_mat_srcptr'):
return mpq_mat_printer(val.dereference())
if (t == 'mpq_mat'):
return mpq_mat_printer(val.dereference())
if (t == 'mpq_mat_s'):
return mpq_mat_printer(val)
if (t == 'cxx_mpq_mat'):
return mpq_mat_printer(val['x'])
except RuntimeError:
# constructors may abandon building if the object looks too complicated.
return None
return None
def remove_all_printers():
while len(gdb.pretty_printers):
gdb.pretty_printers.pop(0)
def hook_mp_printers():
gdb.pretty_printers.append(make_mp_printer_objects)
def unhook_mp_printers():
gdb.pretty_printers.remove(make_mp_printer_objects)
# this is just for easily sourcing this again and again while debugging.
remove_all_printers()
hook_mp_printers()
