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nodejs/tools/genv8constants.py
Fedor Indutny 88217ec276 dtrace: fix generation of v8 constants on freebsd
Every constant is certainly 4 bytes now, but freebsd's objdump utility
prints out odd byte sequences (5-bytes, 6-bytes and even 9-bytes long)
for v8's data section. We can safely ignore all upper bytes, because all
constants that we're using are just `int`s. Since on all supported
platforms `int` is 32bit long (and anyway v8's constants are 32bit too),
we ignore all higher bits if they were read.
2013-03-20 01:11:02 +01:00

115 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.
#
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 = file(sys.argv[1], 'w');
try:
pipe = subprocess.Popen([ 'objdump', '-z', '-D', sys.argv[2] ],
bufsize=-1, stdout=subprocess.PIPE).stdout;
except OSError, 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 intead.
#
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 not numpattern.match(octetstr):
break;
if curr_octet > octets:
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 */
""");