# Copyright 2016 Sasha Goldshtein

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

import ctypes as ct

from .libbcc import lib, bcc_symbol

class ProcessSymbols(object):

def __init__(self, pid):

"""

Initializes the process symbols store for the specified pid.

Call refresh_code_ranges() periodically if you anticipate changes

in the set of loaded libraries or their addresses.

"""

self.cache = lib.bcc_symcache_new(pid)

def refresh_code_ranges(self):

lib.bcc_symcache_refresh(self.cache)

def decode_addr(self, addr):

"""

Given an address, return the best symbolic representation of it.

If it doesn't fall in any module, return its hex string. If it

falls within a module but we don't have a symbol for it, return

the hex string and the module. If we do have a symbol for it,

return the symbol and the module, e.g. "readline+0x10 [bash]".

"""

sym = bcc_symbol()

psym = ct.pointer(sym)

if lib.bcc_symcache_resolve(self.cache, addr, psym) < 0:

if sym.module and sym.offset:

return "0x%x [%s]" % (sym.offset, sym.module)

return "%x" % addr

return "%s+0x%x [%s]" % (sym.name, sym.offset, sym.module)