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#!/usr/bin/env python
#
# Copyright 2012 the V8 project authors. All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following
# disclaimer in the documentation and/or other materials provided
# with the distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
#
# Emits a C++ file to be compiled and linked into libv8 to support postmortem
# debugging tools. Most importantly, this tool emits constants describing V8
# internals:
#
# v8dbg_type_CLASS__TYPE = VALUE Describes class type values
# v8dbg_class_CLASS__FIELD__TYPE = OFFSET Describes class fields
# v8dbg_parent_CLASS__PARENT Describes class hierarchy
# v8dbg_frametype_NAME = VALUE Describes stack frame values
# v8dbg_off_fp_NAME = OFFSET Frame pointer offsets
# v8dbg_prop_NAME = OFFSET Object property offsets
# v8dbg_NAME = VALUE Miscellaneous values
#
# These constants are declared as global integers so that they'll be present in
# the generated libv8 binary.
#
import re
import sys
#
# Miscellaneous constants, tags, and masks used for object identification.
#
consts_misc = [
{ 'name': 'FirstNonstringType', 'value': 'FIRST_NONSTRING_TYPE' },
{ 'name': 'IsNotStringMask', 'value': 'kIsNotStringMask' },
{ 'name': 'StringTag', 'value': 'kStringTag' },
{ 'name': 'NotStringTag', 'value': 'kNotStringTag' },
{ 'name': 'StringEncodingMask', 'value': 'kStringEncodingMask' },
{ 'name': 'TwoByteStringTag', 'value': 'kTwoByteStringTag' },
{ 'name': 'AsciiStringTag', 'value': 'kOneByteStringTag' },
{ 'name': 'StringRepresentationMask',
'value': 'kStringRepresentationMask' },
{ 'name': 'SeqStringTag', 'value': 'kSeqStringTag' },
{ 'name': 'ConsStringTag', 'value': 'kConsStringTag' },
{ 'name': 'ExternalStringTag', 'value': 'kExternalStringTag' },
{ 'name': 'FailureTag', 'value': 'kFailureTag' },
{ 'name': 'FailureTagMask', 'value': 'kFailureTagMask' },
{ 'name': 'HeapObjectTag', 'value': 'kHeapObjectTag' },
{ 'name': 'HeapObjectTagMask', 'value': 'kHeapObjectTagMask' },
{ 'name': 'SmiTag', 'value': 'kSmiTag' },
{ 'name': 'SmiTagMask', 'value': 'kSmiTagMask' },
{ 'name': 'SmiValueShift', 'value': 'kSmiTagSize' },
{ 'name': 'PointerSizeLog2', 'value': 'kPointerSizeLog2' },
{ 'name': 'prop_idx_first',
'value': 'DescriptorArray::kFirstIndex' },
{ 'name': 'prop_type_field',
'value': 'FIELD' },
{ 'name': 'prop_type_first_phantom',
'value': 'TRANSITION' },
{ 'name': 'prop_type_mask',
'value': 'PropertyDetails::TypeField::kMask' },
{ 'name': 'off_fp_context',
'value': 'StandardFrameConstants::kContextOffset' },
{ 'name': 'off_fp_marker',
'value': 'StandardFrameConstants::kMarkerOffset' },
{ 'name': 'off_fp_function',
'value': 'JavaScriptFrameConstants::kFunctionOffset' },
{ 'name': 'off_fp_args',
'value': 'JavaScriptFrameConstants::kLastParameterOffset' },
];
#
# The following useful fields are missing accessors, so we define fake ones.
#
extras_accessors = [
'HeapObject, map, Map, kMapOffset',
'JSObject, elements, Object, kElementsOffset',
'FixedArray, data, uintptr_t, kHeaderSize',
'Map, instance_attributes, int, kInstanceAttributesOffset',
'Map, inobject_properties, int, kInObjectPropertiesOffset',
'Map, instance_size, int, kInstanceSizeOffset',
'HeapNumber, value, double, kValueOffset',
'ConsString, first, String, kFirstOffset',
'ConsString, second, String, kSecondOffset',
'ExternalString, resource, Object, kResourceOffset',
'SeqOneByteString, chars, char, kHeaderSize',
'SharedFunctionInfo, code, Code, kCodeOffset',
'Code, instruction_start, uintptr_t, kHeaderSize',
'Code, instruction_size, int, kInstructionSizeOffset',
];
#
# The following is a whitelist of classes we expect to find when scanning the
# source code. This list is not exhaustive, but it's still useful to identify
# when this script gets out of sync with the source. See load_objects().
#
expected_classes = [
'ConsString', 'FixedArray', 'HeapNumber', 'JSArray', 'JSFunction',
'JSObject', 'JSRegExp', 'JSValue', 'Map', 'Oddball', 'Script',
'SeqOneByteString', 'SharedFunctionInfo'
];
#
# The following structures store high-level representations of the structures
# for which we're going to emit descriptive constants.
#
types = {}; # set of all type names
typeclasses = {}; # maps type names to corresponding class names
klasses = {}; # known classes, including parents
fields = []; # field declarations
header = '''
/*
* This file is generated by %s. Do not edit directly.
*/
#include "v8.h"
#include "frames.h"
#include "frames-inl.h" /* for architecture-specific frame constants */
using namespace v8::internal;
extern "C" {
/* stack frame constants */
#define FRAME_CONST(value, klass) \
int v8dbg_frametype_##klass = StackFrame::value;
STACK_FRAME_TYPE_LIST(FRAME_CONST)
#undef FRAME_CONST
''' % sys.argv[0];
footer = '''
}
'''
#
# Loads class hierarchy and type information from "objects.h".
#
def load_objects():
objfilename = sys.argv[2];
objfile = open(objfilename, 'r');
in_insttype = False;
typestr = '';
#
# Construct a dictionary for the classes we're sure should be present.
#
checktypes = {};
for klass in expected_classes:
checktypes[klass] = True;
#
# Iterate objects.h line-by-line to collect type and class information.
# For types, we accumulate a string representing the entire InstanceType
# enum definition and parse it later because it's easier to do so
# without the embedded newlines.
#
for line in objfile:
if (line.startswith('enum InstanceType {')):
in_insttype = True;
continue;
if (in_insttype and line.startswith('};')):
in_insttype = False;
continue;
line = re.sub('//.*', '', line.rstrip().lstrip());
if (in_insttype):
typestr += line;
continue;
match = re.match('class (\w[^\s:]*)(: public (\w[^\s{]*))?\s*{',
line);
if (match):
klass = match.group(1);
pklass = match.group(3);
klasses[klass] = { 'parent': pklass };
#
# Process the instance type declaration.
#
entries = typestr.split(',');
for entry in entries:
types[re.sub('\s*=.*', '', entry).lstrip()] = True;
#
# Infer class names for each type based on a systematic transformation.
# For example, "JS_FUNCTION_TYPE" becomes "JSFunction". We find the
# class for each type rather than the other way around because there are
# fewer cases where one type maps to more than one class than the other
# way around.
#
for type in types:
#
# Symbols and Strings are implemented using the same classes.
#
usetype = re.sub('SYMBOL_', 'STRING_', type);
#
# REGEXP behaves like REG_EXP, as in JS_REGEXP_TYPE => JSRegExp.
#
usetype = re.sub('_REGEXP_', '_REG_EXP_', usetype);
#
# Remove the "_TYPE" suffix and then convert to camel case,
# except that a "JS" prefix remains uppercase (as in
# "JS_FUNCTION_TYPE" => "JSFunction").
#
if (not usetype.endswith('_TYPE')):
continue;
usetype = usetype[0:len(usetype) - len('_TYPE')];
parts = usetype.split('_');
cctype = '';
if (parts[0] == 'JS'):
cctype = 'JS';
start = 1;
else:
cctype = '';
start = 0;
for ii in range(start, len(parts)):
part = parts[ii];
cctype += part[0].upper() + part[1:].lower();
#
# Mapping string types is more complicated. Both types and
# class names for Strings specify a representation (e.g., Seq,
# Cons, External, or Sliced) and an encoding (TwoByte or Ascii),
# In the simplest case, both of these are explicit in both
# names, as in:
#
# EXTERNAL_ASCII_STRING_TYPE => ExternalAsciiString
#
# However, either the representation or encoding can be omitted
# from the type name, in which case "Seq" and "TwoByte" are
# assumed, as in:
#
# STRING_TYPE => SeqTwoByteString
#
# Additionally, sometimes the type name has more information
# than the class, as in:
#
# CONS_ASCII_STRING_TYPE => ConsString
#
# To figure this out dynamically, we first check for a
# representation and encoding and add them if they're not
# present. If that doesn't yield a valid class name, then we
# strip out the representation.
#
if (cctype.endswith('String')):
if (cctype.find('Cons') == -1 and
cctype.find('External') == -1 and
cctype.find('Sliced') == -1):
if (cctype.find('Ascii') != -1):
cctype = re.sub('AsciiString$',
'SeqOneByteString', cctype);
else:
cctype = re.sub('String$',
'SeqString', cctype);
if (cctype.find('Ascii') == -1):
cctype = re.sub('String$', 'TwoByteString',
cctype);
if (not (cctype in klasses)):
cctype = re.sub('Ascii', '', cctype);
cctype = re.sub('TwoByte', '', cctype);
#
# Despite all that, some types have no corresponding class.
#
if (cctype in klasses):
typeclasses[type] = cctype;
if (cctype in checktypes):
del checktypes[cctype];
if (len(checktypes) > 0):
for klass in checktypes:
print('error: expected class \"%s\" not found' % klass);
sys.exit(1);
#
# For a given macro call, pick apart the arguments and return an object
# describing the corresponding output constant. See load_fields().
#
def parse_field(call):
# Replace newlines with spaces.
for ii in range(0, len(call)):
if (call[ii] == '\n'):
call[ii] == ' ';
idx = call.find('(');
kind = call[0:idx];
rest = call[idx + 1: len(call) - 1];
args = re.split('\s*,\s*', rest);
consts = [];
if (kind == 'ACCESSORS' or kind == 'ACCESSORS_GCSAFE'):
klass = args[0];
field = args[1];
dtype = args[2];
offset = args[3];
return ({
'name': 'class_%s__%s__%s' % (klass, field, dtype),
'value': '%s::%s' % (klass, offset)
});
assert(kind == 'SMI_ACCESSORS');
klass = args[0];
field = args[1];
offset = args[2];
return ({
'name': 'class_%s__%s__%s' % (klass, field, 'SMI'),
'value': '%s::%s' % (klass, offset)
});
#
# Load field offset information from objects-inl.h.
#
def load_fields():
inlfilename = sys.argv[3];
inlfile = open(inlfilename, 'r');
#
# Each class's fields and the corresponding offsets are described in the
# source by calls to macros like "ACCESSORS" (and friends). All we do
# here is extract these macro invocations, taking into account that they
# may span multiple lines and may contain nested parentheses. We also
# call parse_field() to pick apart the invocation.
#
prefixes = [ 'ACCESSORS', 'ACCESSORS_GCSAFE', 'SMI_ACCESSORS' ];
current = '';
opens = 0;
for line in inlfile:
if (opens > 0):
# Continuation line
for ii in range(0, len(line)):
if (line[ii] == '('):
opens += 1;
elif (line[ii] == ')'):
opens -= 1;
if (opens == 0):
break;
current += line[0:ii + 1];
continue;
for prefix in prefixes:
if (not line.startswith(prefix + '(')):
continue;
if (len(current) > 0):
fields.append(parse_field(current));
current = '';
for ii in range(len(prefix), len(line)):
if (line[ii] == '('):
opens += 1;
elif (line[ii] == ')'):
opens -= 1;
if (opens == 0):
break;
current += line[0:ii + 1];
if (len(current) > 0):
fields.append(parse_field(current));
current = '';
for body in extras_accessors:
fields.append(parse_field('ACCESSORS(%s)' % body));
#
# Emit a block of constants.
#
def emit_set(out, consts):
for ii in range(0, len(consts)):
out.write('int v8dbg_%s = %s;\n' %
(consts[ii]['name'], consts[ii]['value']));
out.write('\n');
#
# Emit the whole output file.
#
def emit_config():
out = file(sys.argv[1], 'w');
out.write(header);
out.write('/* miscellaneous constants */\n');
emit_set(out, consts_misc);
out.write('/* class type information */\n');
consts = [];
keys = typeclasses.keys();
keys.sort();
for typename in keys:
klass = typeclasses[typename];
consts.append({
'name': 'type_%s__%s' % (klass, typename),
'value': typename
});
emit_set(out, consts);
out.write('/* class hierarchy information */\n');
consts = [];
keys = klasses.keys();
keys.sort();
for klassname in keys:
pklass = klasses[klassname]['parent'];
if (pklass == None):
continue;
consts.append({
'name': 'parent_%s__%s' % (klassname, pklass),
'value': 0
});
emit_set(out, consts);
out.write('/* field information */\n');
emit_set(out, fields);
out.write(footer);
if (len(sys.argv) < 4):
print('usage: %s output.cc objects.h objects-inl.h' % sys.argv[0]);
sys.exit(2);
load_objects();
load_fields();
emit_config();
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