Commit 9a71bb00 authored by Luuk van Dijk's avatar Luuk van Dijk

[68]l: generate debug info for builtin structured types. prettyprinting in gdb.

R=rsc
CC=golang-dev
https://golang.org/cl/3309041
parent 09e4d860
This diff is collapsed.
# Copyright 2010 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.
"""GDB Pretty printers and convencience functions for Go's runtime structures.
This script is loaded by GDB when it finds a .debug_gdb_scripts
section in the compiled binary. The [68]l linkers emit this with a
path to this file based on the path to the runtime package.
"""
import sys, re
print >>sys.stderr, "Loading Go Runtime support."
#
# Pretty Printers
#
class StringTypePrinter:
"Pretty print Go strings."
pattern = re.compile(r'^struct string$')
def __init__(self, val):
self.val = val
def display_hint(self):
return 'string'
def to_string(self):
return self.val['str']
class SliceTypePrinter:
"Pretty print slices."
pattern = re.compile(r'^struct \[\]')
def __init__(self, val):
self.val = val
def display_hint(self):
return 'array'
def to_string(self):
return str(self.val.type)[6:] # skip 'struct '
def children(self):
ptr = self.val["array"]
for idx in range(self.val["len"]):
yield ('[%d]' % idx, (ptr + idx).dereference())
class MapTypePrinter:
"""Pretty print map[K]V types.
Map-typed go variables are really pointers. dereference them in gdb
to inspect their contents with this pretty printer.
"""
pattern = re.compile(r'^struct hash<.*>$')
def __init__(self, val):
self.val = val
def display_hint(self):
return 'map'
def to_string(self):
return str(self.val.type)
def children(self):
stab = self.val['st']
i = 0
for v in self.traverse_hash(stab):
yield ("[%d]" % i, v['key'])
yield ("[%d]" % (i + 1), v['val'])
i += 2
def traverse_hash(self, stab):
ptr = stab['entry'].address
end = stab['end']
while ptr < end:
v = ptr.dereference()
ptr = ptr + 1
if v['hash'] == 0: continue
if v['hash'] & 63 == 63: # subtable
for v in self.traverse_hash(v['key'].cast(self.val['st'].type)):
yield v
else:
yield v
class ChanTypePrinter:
"""Pretty print chan[T] types.
Map-typed go variables are really pointers. dereference them in gdb
to inspect their contents with this pretty printer.
"""
pattern = re.compile(r'^struct hchan<.*>$')
def __init__(self, val):
self.val = val
def display_hint(self):
return 'array'
def to_string(self):
return str(self.val.type)
def children(self):
ptr = self.val['recvdataq']
for idx in range(self.val["qcount"]):
yield ('[%d]' % idx, ptr['elem'])
ptr = ptr['link']
#
# Register all the *Printer classes
#
def makematcher(klass):
def matcher(val):
try:
if klass.pattern.match(str(val.type)): return klass(val)
except: pass
return matcher
gdb.current_objfile().pretty_printers.extend([makematcher(k) for k in vars().values() if hasattr(k, 'pattern')])
#
# Convenience Functions
#
class GoLenFunc(gdb.Function):
"Length of strings, slices, maps or channels"
how = ((StringTypePrinter, 'len' ),
(SliceTypePrinter, 'len'),
(MapTypePrinter, 'count'),
(ChanTypePrinter, 'qcount'))
def __init__(self):
super(GoLenFunc, self).__init__("len")
def invoke(self, obj):
typename = str(obj.type)
for klass, fld in self.how:
if klass.pattern.match(typename):
return obj[fld]
class GoCapFunc(gdb.Function):
"Capacity of slices or channels"
how = ((SliceTypePrinter, 'cap'),
(ChanTypePrinter, 'dataqsiz'))
def __init__(self):
super(GoCapFunc, self).__init__("cap")
def invoke(self, obj):
typename = str(obj.type)
for klass, fld in self.how:
if klass.pattern.match(typename):
return obj[fld]
#
# Register all convience functions and CLI commands
#
for k in vars().values():
if hasattr(k, 'invoke'):
k()
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