emsymbolizer.py - external/github.com/emscripten-core/emscripten - Git at Google

 #!/usr/bin/env python3

 # This is a utility for looking up the symbol names and/or file+line numbers
 # of code addresses. There are several possible sources of this information,
 # with varying granularity (listed here in approximate preference order).

 # If the wasm has DWARF info, llvm-symbolizer can show the symbol, file, and
 # line/column number, potentially including inlining.
 # If the wasm has separate DWARF info, do the above with the side file
 # If there is a source map, we can parse it to get file and line number.
 # If there is an emscripten symbol map, we can parse that to get the symbol name
 # If there is a name section or symbol table, llvm-nm can show the symbol name.

 import argparse
 import json
 import os
 import re
 import subprocess
 import sys
 from tools import shared
 from tools import webassembly

 LLVM_SYMBOLIZER = os.path.expanduser(
     shared.build_llvm_tool_path(shared.exe_suffix('llvm-symbolizer')))


 class Error(BaseException):
   pass


 # Class to treat location info in a uniform way across information sources.
 class LocationInfo(object):
   def __init__(self, source=None, line=0, column=0, func=None):
     self.source = source
     self.line = line
     self.column = column
     self.func = func

   def print(self):
     source = self.source if self.source else '??'
     func = self.func if self.func else '??'
     print(f'{func}\n{source}:{self.line}:{self.column}')


 def get_codesec_offset(module):
   sec = module.get_section(webassembly.SecType.CODE)
   if not sec:
     raise Error(f'No code section found in {module.filename}')
   return sec.offset


 def has_debug_line_section(module):
   for sec in module.sections():
     if sec.name == ".debug_line":
       return True
   return False


 def symbolize_address_dwarf(module, address):
   vma_adjust = get_codesec_offset(module)
   cmd = [LLVM_SYMBOLIZER, '-e', module.filename, f'--adjust-vma={vma_adjust}',
          str(address)]
   out = shared.run_process(cmd, stdout=subprocess.PIPE).stdout.strip()
   out_lines = out.splitlines()
   # Source location regex, e.g., /abc/def.c:3:5
   SOURCE_LOC_RE = re.compile(r'(.+):(\d+):(\d+)$')
   # llvm-dwarfdump prints two lines per location. The first line contains a
   # function name, and the second contains a source location like
   # '/abc/def.c:3:5'. If the function or source info is not available, it will
   # be printed as '??', in which case we store None. If the line and column info
   # is not available, they will be printed as 0, which we store as is.
   for i in range(0, len(out_lines), 2):
     func, loc_str = out_lines[i], out_lines[i + 1]
     m = SOURCE_LOC_RE.match(loc_str)
     source, line, column = m.group(1), m.group(2), m.group(3)
     if func == '??':
       func = None
     if source == '??':
       source = None
     LocationInfo(source, line, column, func).print()


 def get_sourceMappingURL_section(module):
   for sec in module.sections():
     if sec.name == "sourceMappingURL":
       return sec
   return None


 class WasmSourceMap(object):
   class Location(object):
     def __init__(self, source=None, line=0, column=0, func=None):
       self.source = source
       self.line = line
       self.column = column
       self.func = func

   def __init__(self):
     self.version = None
     self.sources = []
     self.mappings = {}
     self.offsets = []

   def parse(self, filename):
     with open(filename) as f:
       source_map_json = json.loads(f.read())
       if shared.DEBUG:
         print(source_map_json)

     self.version = source_map_json['version']
     self.sources = source_map_json['sources']

     vlq_map = {}
     chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
     for i, c in enumerate(chars):
       vlq_map[c] = i

     def decodeVLQ(string):
       result = []
       shift = 0
       value = 0
       for c in string:
         try:
           integer = vlq_map[c]
         except ValueError:
           raise Error(f'Invalid character ({c}) in VLQ')
         value += (integer & 31) << shift
         if integer & 32:
           shift += 5
         else:
           negate = value & 1
           value >>= 1
           result.append(-value if negate else value)
           value = shift = 0
       return result

     offset = 0
     src = 0
     line = 1
     col = 1
     for segment in source_map_json['mappings'].split(','):
       data = decodeVLQ(segment)
       info = []

       offset += data[0]
       if len(data) >= 2:
         src += data[1]
         info.append(src)
       if len(data) >= 3:
         line += data[2]
         info.append(line)
       if len(data) >= 4:
         col += data[3]
         info.append(col)
       # TODO: see if we need the name, which is the next field (data[4])

       self.mappings[offset] = WasmSourceMap.Location(*info)
       self.offsets.append(offset)
     self.offsets.sort()

   def find_offset(self, offset):
     # Find the largest mapped offset <= the search offset
     lo = 0
     hi = len(self.offsets)

     while lo < hi:
       mid = (lo + hi) // 2
       if self.offsets[mid] > offset:
         hi = mid
       else:
         lo = mid + 1
     return self.offsets[lo - 1]

   def lookup(self, offset):
     nearest = self.find_offset(offset)
     assert nearest in self.mappings, 'Sourcemap has an offset with no mapping'
     info = self.mappings[nearest]
     return LocationInfo(
         self.sources[info.source] if info.source is not None else None,
         info.line,
         info.column
       )


 def symbolize_address_sourcemap(module, address, force_file):
   URL = force_file
   if not URL:
     # If a sourcemap file is not forced, read it from the wasm module
     section = get_sourceMappingURL_section(module)
     assert section
     module.seek(section.offset)
     assert module.read_string() == 'sourceMappingURL'
     # TODO: support stripping/replacing a prefix from the URL
     URL = module.read_string()

   if shared.DEBUG:
     print(f'Source Mapping URL: {URL}')
   sm = WasmSourceMap()
   sm.parse(URL)
   if shared.DEBUG:
     csoff = get_codesec_offset(module)
     print(sm.mappings)
     # Print with section offsets to easily compare against dwarf
     for k, v in sm.mappings.items():
       print(f'{k-csoff:x}: {v}')
   sm.lookup(address).print()


 def main(args):
   with webassembly.Module(args.wasm_file) as module:
     base = 16 if args.address.lower().startswith('0x') else 10
     address = int(args.address, base)
     symbolized = 0

     if args.addrtype == 'code':
       address += get_codesec_offset(module)

     if ((has_debug_line_section(module) and not args.source) or
        'dwarf' in args.source):
       symbolize_address_dwarf(module, address)
       symbolized += 1

     if ((get_sourceMappingURL_section(module) and not args.source) or
        'sourcemap' in args.source):
       symbolize_address_sourcemap(module, address, args.file)
       symbolized += 1

     if not symbolized:
       raise Error('No .debug_line or sourceMappingURL section found in '
                   f'{module.filename}.'
                   " I don't know how to symbolize this file yet")


 def get_args():
   parser = argparse.ArgumentParser()
   parser.add_argument('-s', '--source', choices=['dwarf', 'sourcemap'],
                       help='Force debug info source type', default=())
   parser.add_argument('-f', '--file', action='store',
                       help='Force debug info source file')
   parser.add_argument('-t', '--addrtype', choices=['code', 'file'],
                       default='file',
                       help='Address type (code section or file offset)')
   parser.add_argument('-v', '--verbose', action='store_true',
                       help='Print verbose info for debugging this script')
   parser.add_argument('wasm_file', help='Wasm file')
   parser.add_argument('address', help='Address to lookup')
   args = parser.parse_args()
   if args.verbose:
     shared.PRINT_STAGES = 1
     shared.DEBUG = True
   return args


 if __name__ == '__main__':
   try:
     rv = main(get_args())
   except (Error, webassembly.InvalidWasmError, OSError) as e:
     print(f'{sys.argv[0]}: {str(e)}', file=sys.stderr)
     rv = 1
   sys.exit(rv)
	#!/usr/bin/env python3

	# This is a utility for looking up the symbol names and/or file+line numbers
	# of code addresses. There are several possible sources of this information,
	# with varying granularity (listed here in approximate preference order).

	# If the wasm has DWARF info, llvm-symbolizer can show the symbol, file, and
	# line/column number, potentially including inlining.
	# If the wasm has separate DWARF info, do the above with the side file
	# If there is a source map, we can parse it to get file and line number.
	# If there is an emscripten symbol map, we can parse that to get the symbol name
	# If there is a name section or symbol table, llvm-nm can show the symbol name.

	import argparse
	import json
	import os
	import re
	import subprocess
	import sys
	from tools import shared
	from tools import webassembly

	LLVM_SYMBOLIZER = os.path.expanduser(
	shared.build_llvm_tool_path(shared.exe_suffix('llvm-symbolizer')))


	class Error(BaseException):
	pass


	# Class to treat location info in a uniform way across information sources.
	class LocationInfo(object):
	def __init__(self, source=None, line=0, column=0, func=None):
	self.source = source
	self.line = line
	self.column = column
	self.func = func

	def print(self):
	source = self.source if self.source else '??'
	func = self.func if self.func else '??'
	print(f'{func}\n{source}:{self.line}:{self.column}')


	def get_codesec_offset(module):
	sec = module.get_section(webassembly.SecType.CODE)
	if not sec:
	raise Error(f'No code section found in {module.filename}')
	return sec.offset


	def has_debug_line_section(module):
	for sec in module.sections():
	if sec.name == ".debug_line":
	return True
	return False


	def symbolize_address_dwarf(module, address):
	vma_adjust = get_codesec_offset(module)
	cmd = [LLVM_SYMBOLIZER, '-e', module.filename, f'--adjust-vma={vma_adjust}',
	str(address)]
	out = shared.run_process(cmd, stdout=subprocess.PIPE).stdout.strip()
	out_lines = out.splitlines()
	# Source location regex, e.g., /abc/def.c:3:5
	SOURCE_LOC_RE = re.compile(r'(.+):(\d+):(\d+)$')
	# llvm-dwarfdump prints two lines per location. The first line contains a
	# function name, and the second contains a source location like
	# '/abc/def.c:3:5'. If the function or source info is not available, it will
	# be printed as '??', in which case we store None. If the line and column info
	# is not available, they will be printed as 0, which we store as is.
	for i in range(0, len(out_lines), 2):
	func, loc_str = out_lines[i], out_lines[i + 1]
	m = SOURCE_LOC_RE.match(loc_str)
	source, line, column = m.group(1), m.group(2), m.group(3)
	if func == '??':
	func = None
	if source == '??':
	source = None
	LocationInfo(source, line, column, func).print()


	def get_sourceMappingURL_section(module):
	for sec in module.sections():
	if sec.name == "sourceMappingURL":
	return sec
	return None


	class WasmSourceMap(object):
	class Location(object):
	def __init__(self, source=None, line=0, column=0, func=None):
	self.source = source
	self.line = line
	self.column = column
	self.func = func

	def __init__(self):
	self.version = None
	self.sources = []
	self.mappings = {}
	self.offsets = []

	def parse(self, filename):
	with open(filename) as f:
	source_map_json = json.loads(f.read())
	if shared.DEBUG:
	print(source_map_json)

	self.version = source_map_json['version']
	self.sources = source_map_json['sources']

	vlq_map = {}
	chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
	for i, c in enumerate(chars):
	vlq_map[c] = i

	def decodeVLQ(string):
	result = []
	shift = 0
	value = 0
	for c in string:
	try:
	integer = vlq_map[c]
	except ValueError:
	raise Error(f'Invalid character ({c}) in VLQ')
	value += (integer & 31) << shift
	if integer & 32:
	shift += 5
	else:
	negate = value & 1
	value >>= 1
	result.append(-value if negate else value)
	value = shift = 0
	return result

	offset = 0
	src = 0
	line = 1
	col = 1
	for segment in source_map_json['mappings'].split(','):
	data = decodeVLQ(segment)
	info = []

	offset += data[0]
	if len(data) >= 2:
	src += data[1]
	info.append(src)
	if len(data) >= 3:
	line += data[2]
	info.append(line)
	if len(data) >= 4:
	col += data[3]
	info.append(col)
	# TODO: see if we need the name, which is the next field (data[4])

	self.mappings[offset] = WasmSourceMap.Location(*info)
	self.offsets.append(offset)
	self.offsets.sort()

	def find_offset(self, offset):
	# Find the largest mapped offset <= the search offset
	lo = 0
	hi = len(self.offsets)

	while lo < hi:
	mid = (lo + hi) // 2
	if self.offsets[mid] > offset:
	hi = mid
	else:
	lo = mid + 1
	return self.offsets[lo - 1]

	def lookup(self, offset):
	nearest = self.find_offset(offset)
	assert nearest in self.mappings, 'Sourcemap has an offset with no mapping'
	info = self.mappings[nearest]
	return LocationInfo(
	self.sources[info.source] if info.source is not None else None,
	info.line,
	info.column
	)


	def symbolize_address_sourcemap(module, address, force_file):
	URL = force_file
	if not URL:
	# If a sourcemap file is not forced, read it from the wasm module
	section = get_sourceMappingURL_section(module)
	assert section
	module.seek(section.offset)
	assert module.read_string() == 'sourceMappingURL'
	# TODO: support stripping/replacing a prefix from the URL
	URL = module.read_string()

	if shared.DEBUG:
	print(f'Source Mapping URL: {URL}')
	sm = WasmSourceMap()
	sm.parse(URL)
	if shared.DEBUG:
	csoff = get_codesec_offset(module)
	print(sm.mappings)
	# Print with section offsets to easily compare against dwarf
	for k, v in sm.mappings.items():
	print(f'{k-csoff:x}: {v}')
	sm.lookup(address).print()


	def main(args):
	with webassembly.Module(args.wasm_file) as module:
	base = 16 if args.address.lower().startswith('0x') else 10
	address = int(args.address, base)
	symbolized = 0

	if args.addrtype == 'code':
	address += get_codesec_offset(module)

	if ((has_debug_line_section(module) and not args.source) or
	'dwarf' in args.source):
	symbolize_address_dwarf(module, address)
	symbolized += 1

	if ((get_sourceMappingURL_section(module) and not args.source) or
	'sourcemap' in args.source):
	symbolize_address_sourcemap(module, address, args.file)
	symbolized += 1

	if not symbolized:
	raise Error('No .debug_line or sourceMappingURL section found in '
	f'{module.filename}.'
	" I don't know how to symbolize this file yet")


	def get_args():
	parser = argparse.ArgumentParser()
	parser.add_argument('-s', '--source', choices=['dwarf', 'sourcemap'],
	help='Force debug info source type', default=())
	parser.add_argument('-f', '--file', action='store',
	help='Force debug info source file')
	parser.add_argument('-t', '--addrtype', choices=['code', 'file'],
	default='file',
	help='Address type (code section or file offset)')
	parser.add_argument('-v', '--verbose', action='store_true',
	help='Print verbose info for debugging this script')
	parser.add_argument('wasm_file', help='Wasm file')
	parser.add_argument('address', help='Address to lookup')
	args = parser.parse_args()
	if args.verbose:
	shared.PRINT_STAGES = 1
	shared.DEBUG = True
	return args


	if __name__ == '__main__':
	try:
	rv = main(get_args())
	except (Error, webassembly.InvalidWasmError, OSError) as e:
	print(f'{sys.argv[0]}: {str(e)}', file=sys.stderr)
	rv = 1
	sys.exit(rv)