nodejs/tools/genv8constants.py

116 lines
2.7 KiB
Python
Executable File

#!/usr/bin/env python
#
# genv8constants.py output_file libv8_base.a
#
# Emits v8dbg constants stored in libv8_base.a in a format suitable for the V8
# ustack helper.
#
from __future__ import print_function
import re
import subprocess
import sys
import errno
if len(sys.argv) != 3:
print("usage: objsym.py outfile libv8_base.a")
sys.exit(2)
outfile = open(sys.argv[1], 'w')
try:
pipe = subprocess.Popen([ 'objdump', '-z', '-D', sys.argv[2] ],
bufsize=-1, stdout=subprocess.PIPE).stdout
except OSError as e:
if e.errno == errno.ENOENT:
print('''
Node.js compile error: could not find objdump
Check that GNU binutils are installed and included in PATH
''')
else:
print('problem running objdump: ', e.strerror)
sys.exit()
pattern = re.compile('([0-9a-fA-F]{8}|[0-9a-fA-F]{16}) <(.*)>:')
v8dbg = re.compile('^v8dbg.*$')
numpattern = re.compile('^[0-9a-fA-F]{2} $')
octets = 4
outfile.write("""
/*
* File automatically generated by genv8constants. Do not edit.
*
* The following offsets are dynamically from libv8_base.a. See src/v8ustack.d
* for details on how these values are used.
*/
#ifndef V8_CONSTANTS_H
#define V8_CONSTANTS_H
""")
curr_sym = None
curr_val = 0
curr_octet = 0
def out_reset():
global curr_sym, curr_val, curr_octet
curr_sym = None
curr_val = 0
curr_octet = 0
def out_define():
global curr_sym, curr_val, curr_octet, outfile, octets
if curr_sym != None:
wrapped_val = curr_val & 0xffffffff
if curr_val & 0x80000000 != 0:
wrapped_val = 0x100000000 - wrapped_val
outfile.write("#define %s -0x%x\n" % (curr_sym.upper(), wrapped_val))
else:
outfile.write("#define %s 0x%x\n" % (curr_sym.upper(), wrapped_val))
out_reset()
for line in pipe:
if curr_sym != None:
#
# This bit of code has nasty knowledge of the objdump text output
# format, but this is the most obvious robust approach. We could almost
# rely on looking at numbered fields, but some instructions look very
# much like hex numbers (e.g., "adc"), and we don't want to risk picking
# those up by mistake, so we look at character-based columns instead.
#
for i in range(0, 3):
# 6-character margin, 2-characters + 1 space for each field
idx = 6 + i * 3
octetstr = line[idx:idx+3]
if curr_octet > octets:
break
if not numpattern.match(octetstr):
break
curr_val += int('0x%s' % octetstr, 16) << (curr_octet * 8)
curr_octet += 1
match = pattern.match(line)
if match == None:
continue
# Print previous symbol
out_define()
v8match = v8dbg.match(match.group(2))
if v8match != None:
out_reset()
curr_sym = match.group(2)
# Print last symbol
out_define()
outfile.write("""
#endif /* V8_CONSTANTS_H */
""")