#!/usr/bin/python
#
# Copyright (C) 2013 The Android Open Source Project
#
# 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.
"""Module for looking up symbolic debugging information.
The information can include symbol names, offsets, and source locations.
"""
import glob
import os
import platform
import re
import subprocess
import unittest
ANDROID_BUILD_TOP = os.environ["ANDROID_BUILD_TOP"]
if not ANDROID_BUILD_TOP:
ANDROID_BUILD_TOP = "."
def FindSymbolsDir():
saveddir = os.getcwd()
os.chdir(ANDROID_BUILD_TOP)
try:
cmd = ("CALLED_FROM_SETUP=true BUILD_SYSTEM=build/core "
"SRC_TARGET_DIR=build/target make -f build/core/config.mk "
"dumpvar-abs-TARGET_OUT_UNSTRIPPED")
stream = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True).stdout
return os.path.join(ANDROID_BUILD_TOP, stream.read().strip())
finally:
os.chdir(saveddir)
SYMBOLS_DIR = FindSymbolsDir()
ARCH = "arm"
# These are private. Do not access them from other modules.
_CACHED_TOOLCHAIN = None
_CACHED_TOOLCHAIN_ARCH = None
def ToolPath(tool, toolchain=None):
"""Return a fully-qualified path to the specified tool"""
if not toolchain:
toolchain = FindToolchain()
return glob.glob(os.path.join(toolchain, "*-" + tool))[0]
def FindToolchain():
"""Returns the toolchain matching ARCH."""
global _CACHED_TOOLCHAIN, _CACHED_TOOLCHAIN_ARCH
if _CACHED_TOOLCHAIN is not None and _CACHED_TOOLCHAIN_ARCH == ARCH:
return _CACHED_TOOLCHAIN
# We use slightly different names from GCC, and there's only one toolchain
# for x86/x86_64. Note that these are the names of the top-level directory
# rather than the _different_ names used lower down the directory hierarchy!
gcc_dir = ARCH
if gcc_dir == "arm64":
gcc_dir = "aarch64"
elif gcc_dir == "mips64":
gcc_dir = "mips"
elif gcc_dir == "x86_64":
gcc_dir = "x86"
os_name = platform.system().lower();
available_toolchains = glob.glob("%s/prebuilts/gcc/%s-x86/%s/*-linux-*/bin/" % (ANDROID_BUILD_TOP, os_name, gcc_dir))
if len(available_toolchains) == 0:
raise Exception("Could not find tool chain for %s" % (ARCH))
toolchain = sorted(available_toolchains)[-1]
if not os.path.exists(ToolPath("addr2line", toolchain)):
raise Exception("No addr2line for %s" % (toolchain))
_CACHED_TOOLCHAIN = toolchain
_CACHED_TOOLCHAIN_ARCH = ARCH
print "Using %s toolchain from: %s" % (_CACHED_TOOLCHAIN_ARCH, _CACHED_TOOLCHAIN)
return _CACHED_TOOLCHAIN
def SymbolInformation(lib, addr):
"""Look up symbol information about an address.
Args:
lib: library (or executable) pathname containing symbols
addr: string hexidecimal address
Returns:
A list of the form [(source_symbol, source_location,
object_symbol_with_offset)].
If the function has been inlined then the list may contain
more than one element with the symbols for the most deeply
nested inlined location appearing first. The list is
always non-empty, even if no information is available.
Usually you want to display the source_location and
object_symbol_with_offset from the last element in the list.
"""
info = SymbolInformationForSet(lib, set([addr]))
return (info and info.get(addr)) or [(None, None, None)]
def SymbolInformationForSet(lib, unique_addrs):
"""Look up symbol information for a set of addresses from the given library.
Args:
lib: library (or executable) pathname containing symbols
unique_addrs: set of hexidecimal addresses
Returns:
A dictionary of the form {addr: [(source_symbol, source_location,
object_symbol_with_offset)]} where each address has a list of
associated symbols and locations. The list is always non-empty.
If the function has been inlined then the list may contain
more than one element with the symbols for the most deeply
nested inlined location appearing first. The list is
always non-empty, even if no information is available.
Usually you want to display the source_location and
object_symbol_with_offset from the last element in the list.
"""
if not lib:
return None
addr_to_line = CallAddr2LineForSet(lib, unique_addrs)
if not addr_to_line:
return None
addr_to_objdump = CallObjdumpForSet(lib, unique_addrs)
if not addr_to_objdump:
return None
result = {}
for addr in unique_addrs:
source_info = addr_to_line.get(addr)
if not source_info:
source_info = [(None, None)]
if addr in addr_to_objdump:
(object_symbol, object_offset) = addr_to_objdump.get(addr)
object_symbol_with_offset = FormatSymbolWithOffset(object_symbol,
object_offset)
else:
object_symbol_with_offset = None
result[addr] = [(source_symbol, source_location, object_symbol_with_offset)
for (source_symbol, source_location) in source_info]
return result
def CallAddr2LineForSet(lib, unique_addrs):
"""Look up line and symbol information for a set of addresses.
Args:
lib: library (or executable) pathname containing symbols
unique_addrs: set of string hexidecimal addresses look up.
Returns:
A dictionary of the form {addr: [(symbol, file:line)]} where
each address has a list of associated symbols and locations
or an empty list if no symbol information was found.
If the function has been inlined then the list may contain
more than one element with the symbols for the most deeply
nested inlined location appearing first.
"""
if not lib:
return None
symbols = SYMBOLS_DIR + lib
if not os.path.exists(symbols):
return None
cmd = [ToolPath("addr2line"), "--functions", "--inlines",
"--demangle", "--exe=" + symbols]
child = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
result = {}
addrs = sorted(unique_addrs)
for addr in addrs:
child.stdin.write("0x%s\n" % addr)
child.stdin.flush()
records = []
first = True
while True:
symbol = child.stdout.readline().strip()
if symbol == "??":
symbol = None
location = child.stdout.readline().strip()
if location == "??:0":
location = None
if symbol is None and location is None:
break
records.append((symbol, location))
if first:
# Write a blank line as a sentinel so we know when to stop
# reading inlines from the output.
# The blank line will cause addr2line to emit "??\n??:0\n".
child.stdin.write("\n")
first = False
result[addr] = records
child.stdin.close()
child.stdout.close()
return result
def StripPC(addr):
"""Strips the Thumb bit a program counter address when appropriate.
Args:
addr: the program counter address
Returns:
The stripped program counter address.
"""
global ARCH
if ARCH == "arm":
return addr & ~1
return addr
def CallObjdumpForSet(lib, unique_addrs):
"""Use objdump to find out the names of the containing functions.
Args:
lib: library (or executable) pathname containing symbols
unique_addrs: set of string hexidecimal addresses to find the functions for.
Returns:
A dictionary of the form {addr: (string symbol, offset)}.
"""
if not lib:
return None
symbols = SYMBOLS_DIR + lib
if not os.path.exists(symbols):
return None
symbols = SYMBOLS_DIR + lib
if not os.path.exists(symbols):
return None
addrs = sorted(unique_addrs)
start_addr_dec = str(StripPC(int(addrs[0], 16)))
stop_addr_dec = str(StripPC(int(addrs[-1], 16)) + 8)
cmd = [ToolPath("objdump"),
"--section=.text",
"--demangle",
"--disassemble",
"--start-address=" + start_addr_dec,
"--stop-address=" + stop_addr_dec,
symbols]
# Function lines look like:
# 000177b0 <android::IBinder::~IBinder()+0x2c>:
# We pull out the address and function first. Then we check for an optional
# offset. This is tricky due to functions that look like "operator+(..)+0x2c"
func_regexp = re.compile("(^[a-f0-9]*) \<(.*)\>:$")
offset_regexp = re.compile("(.*)\+0x([a-f0-9]*)")
# A disassembly line looks like:
# 177b2: b510 push {r4, lr}
asm_regexp = re.compile("(^[ a-f0-9]*):[ a-f0-0]*.*$")
current_symbol = None # The current function symbol in the disassembly.
current_symbol_addr = 0 # The address of the current function.
addr_index = 0 # The address that we are currently looking for.
stream = subprocess.Popen(cmd, stdout=subprocess.PIPE).stdout
result = {}
for line in stream:
# Is it a function line like:
# 000177b0 <android::IBinder::~IBinder()>:
components = func_regexp.match(line)
if components:
# This is a new function, so record the current function and its address.
current_symbol_addr = int(components.group(1), 16)
current_symbol = components.group(2)
# Does it have an optional offset like: "foo(..)+0x2c"?
components = offset_regexp.match(current_symbol)
if components:
current_symbol = components.group(1)
offset = components.group(2)
if offset:
current_symbol_addr -= int(offset, 16)
# Is it an disassembly line like:
# 177b2: b510 push {r4, lr}
components = asm_regexp.match(line)
if components:
addr = components.group(1)
target_addr = addrs[addr_index]
i_addr = int(addr, 16)
i_target = StripPC(int(target_addr, 16))
if i_addr == i_target:
result[target_addr] = (current_symbol, i_target - current_symbol_addr)
addr_index += 1
if addr_index >= len(addrs):
break
stream.close()
return result
def CallCppFilt(mangled_symbol):
cmd = [ToolPath("c++filt")]
process = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
process.stdin.write(mangled_symbol)
process.stdin.write("\n")
process.stdin.close()
demangled_symbol = process.stdout.readline().strip()
process.stdout.close()
return demangled_symbol
def FormatSymbolWithOffset(symbol, offset):
if offset == 0:
return symbol
return "%s+%d" % (symbol, offset)
class FindToolchainTests(unittest.TestCase):
def assert_toolchain_found(self, abi):
global ARCH
ARCH = abi
FindToolchain() # Will throw on failure.
def test_toolchains_found(self):
self.assert_toolchain_found("arm")
self.assert_toolchain_found("arm64")
self.assert_toolchain_found("mips")
self.assert_toolchain_found("x86")
self.assert_toolchain_found("x86_64")
if __name__ == '__main__':
unittest.main()