"""GDB pretty-printer macros for GNU Make."""
import gdb # pylint: disable=import-error
import gdb.printing # pylint: disable=import-error
# Memoize types we commonly use
_TYPES = {}
def getType(tname):
"""Given a type name return a GDB type."""
global _TYPES
if tname not in _TYPES:
tn = tname.rstrip('*')
if tn not in _TYPES:
_TYPES[tn] = gdb.lookup_type(tn)
while tn != tname:
# Want a pointer type
t = tn
tn += '*'
_TYPES[tn] = _TYPES[t].pointer()
return _TYPES[tname]
def isNullptr(val):
"""Return True if the value is a null pointer."""
return int(val.cast(getType('unsigned long long'))) == 0
class ShowArgv(gdb.Command):
"""Print a null-terminated array of strings.
Argument:
A char** where the last one is NULL (e.g., argv)
"""
def __init__(self):
"""Create the showargv function."""
gdb.Command.__init__(self, "showargv", gdb.COMMAND_USER)
def invoke(self, arg, from_tty):
"""Show the argv."""
args = gdb.string_to_argv(arg)
if len(args) != 1:
raise gdb.GdbError(self._usage)
val = gdb.parse_and_eval(args[0])
if val is None:
raise gdb.GdbError('%s is not a valid expression' % (args[0]))
strs = []
while not isNullptr(val.dereference()):
strs.append('"'+val.dereference().string()+'"')
val += 1
gdb.write("[%d] = [%s]\n" % (len(strs), ', '.join(strs)))
gdb.flush()
ShowArgv()
class ShowNextList(gdb.Command):
"""Print a structure that has a "next" pointer.
Argument:
A pointer to a struct which contains a "next" member.
"""
_usage = 'usage: showlist <listptr>'
def __init__(self):
"""Create a "showlist" function."""
gdb.Command.__init__(self, "showlist", gdb.COMMAND_USER)
def invoke(self, arg, from_tty):
"""Show the elements in the provided list."""
args = gdb.string_to_argv(arg)
if len(args) != 1:
raise gdb.GdbError(self._usage)
val = gdb.parse_and_eval(args[0])
if val is None:
raise gdb.GdbError('%s is not a valid expression' % (args[0]))
i = 0
while not isNullptr(val):
gdb.write("%s : %s\n" % (val, val.dereference()))
gdb.flush()
i += 1
val = val['next']
gdb.write("%s contains %d elements\n" % (args[0], i))
gdb.flush()
ShowNextList()
class FileLocation(object):
"""Print a file location."""
def __init__(self, val):
"""Create a FileLocation object."""
self.val = val
def to_string(self):
"""Convert a FileLocation to a string."""
if int(self.val['filenm']):
return "%s:%d" % (str(self.val['filenm']), self.val['lineno'])
return 'NILF'
class StringListPrinter(object):
"""Print a stringlist."""
def __init__(self, val):
"""Create a StringListPrinter object."""
self.val = val
def to_string(self):
"""Convert a HashTable into a string."""
return "size=%d, capacity=%d" % (self.val['idx'], self.val['max'])
def children(self):
"""Yield each string in the list."""
i = 0
elts = self.val['list']
while i < self.val['idx']:
nm = '[%d] ' % i
yield (nm, elts.dereference())
i += 1
elts += 1
def display_hint(self):
"""Show the display hint for the pretty-printer."""
return 'array'
class VariablePrinter(object):
"""Print a struct variable."""
def __init__(self, val):
"""Create a VariablePrinter object."""
self.val = val
def to_string(self):
"""Convert a VariablePrinter object into a string."""
if self.val['append']:
a = '+='
elif self.val['conditional']:
a = '?='
else:
a = '='
flags = []
s = str(self.val['flavor'])
if s != 'f_bogus':
flags.append(s)
s = str(self.val['origin'])
if s != 'o_default':
flags.append(s)
s = str(self.val['export'])
if s != 'v_default':
flags.append(s)
return '%s[%s]: "%s" %s "%s"' % (
self.val['fileinfo'], ','.join(flags),
self.val['name'].string(), a, self.val['value'].string())
class HashTablePrinter(object):
"""Pretty-print a hash table."""
DELITEM = None
def __init__(self, val):
"""Create a HashTablePrinter object."""
self.val = val
def to_string(self):
"""Convert a HashTable into a string."""
return "size=%d, capacity=%d, empty=%d, collisions=%d, rehashes=%d" % (
self.val['ht_size'], self.val['ht_capacity'],
self.val['ht_empty_slots'], self.val['ht_collisions'],
self.val['ht_rehashes'])
def children(self):
"""Yield each ID and value."""
for (i, v) in self.iterator():
nm = '[%d] ' % i
yield (nm, i)
yield (nm, v)
def iterator(self):
"""Provide an iterator for HashTable."""
if HashTablePrinter.DELITEM is None:
HashTablePrinter.DELITEM = gdb.lookup_global_symbol('hash_deleted_item').value()
lst = self.val['ht_vec']
for i in range(0, self.val['ht_size']):
v = lst[i]
if int(v) != 0 and v != HashTablePrinter.DELITEM:
yield (i, v)
def display_hint(self):
"""Show the display hint for the pretty-printer."""
return 'map'
class VariableSetPrinter(object):
"""Print a variable_set."""
def __init__(self, val):
"""Create a variable_set pretty-printer."""
self.tbl = HashTablePrinter(val['table'])
def to_string(self):
"""Convert a variable_set to string."""
return self.tbl.to_string()
def children(self):
"""Iterate through variables and values."""
for (i, v) in self.tbl.iterator():
ptr = v.cast(getType('struct variable*'))
nm = '[%d] ' % (i)
yield (nm, ptr)
yield (nm, str(ptr.dereference()))
def display_hint(self):
"""Show the display hint for the pretty-printer."""
return 'map'
class VariableSetListPrinter(object):
"""Print a variable_set_list."""
GLOBALSET = None
def __init__(self, val):
"""Create a variable_set_list pretty-printer."""
self.val = val
def to_string(self):
"""Convert a variable_set_list to string."""
return str(self.val.address)
def children(self):
"""Iterate through variables and values."""
if VariableSetListPrinter.GLOBALSET is None:
block = gdb.lookup_global_symbol('init_hash_global_variable_set').symtab.static_block()
VariableSetListPrinter.GLOBALSET = gdb.lookup_symbol(
'global_variable_set', block)[0].value().address
ptr = self.val.address
i = 0
while not isNullptr(ptr):
nm = '[%d] ' % (i)
yield (nm, ptr['set'])
if int(ptr['set']) == int(VariableSetListPrinter.GLOBALSET):
yield (nm, "global_variable_set")
else:
yield (nm, str(ptr['set'].dereference()))
i += 1
ptr = ptr['next']
def display_hint(self):
"""Show the display hint for the pretty-printer."""
return 'map'
def build_pretty_printer():
"""Install all the pretty-printers."""
pp = gdb.printing.RegexpCollectionPrettyPrinter("gnumake")
pp.add_printer('floc', r'^floc$', FileLocation)
pp.add_printer('stringlist', r'^stringlist$', StringListPrinter)
pp.add_printer('variable', r'^variable$', VariablePrinter)
pp.add_printer('hashtable', r'^hash_table$', HashTablePrinter)
pp.add_printer('variableset', r'^variable_set$', VariableSetPrinter)
pp.add_printer('variablesetlist', r'^variable_set_list$', VariableSetListPrinter)
return pp
# Use replace=True so we can re-source this file
gdb.printing.register_pretty_printer(gdb.current_objfile(),
build_pretty_printer(), replace=True)
