#!/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': 'kAsciiStringTag' }, { '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_content', 'value': 'DescriptorArray::kContentArrayIndex' }, { 'name': 'prop_idx_first', 'value': 'DescriptorArray::kFirstIndex' }, { 'name': 'prop_type_field', 'value': 'FIELD' }, { 'name': 'prop_type_first_phantom', 'value': 'MAP_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, instance_descriptors, int, kInstanceDescriptorsOrBitField3Offset', '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', 'SeqAsciiString, 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', 'SeqAsciiString', '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$', 'SeqAsciiString', cctype); else: cctype = re.sub('String$', '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();