emscripten/tools/webidl_binder.py

526 строки
16 KiB
Python

'''
WebIDL binder
http://kripken.github.io/emscripten-site/docs/porting/connecting_cpp_and_javascript/WebIDL-Binder.html
'''
import os, sys
import shared
sys.path.append(shared.path_from_root('third_party'))
sys.path.append(shared.path_from_root('third_party', 'ply'))
import WebIDL
class Dummy:
def __init__(self, init):
for k, v in init.iteritems():
self.__dict__[k] = v
def getExtendedAttribute(self, name):
return None
input_file = sys.argv[1]
output_base = sys.argv[2]
shared.try_delete(output_base + '.cpp')
shared.try_delete(output_base + '.js')
p = WebIDL.Parser()
p.parse(r'''
interface VoidPtr {
};
''' + open(input_file).read())
data = p.finish()
interfaces = {}
implements = {}
enums = {}
for thing in data:
if isinstance(thing, WebIDL.IDLInterface):
interfaces[thing.identifier.name] = thing
elif isinstance(thing, WebIDL.IDLImplementsStatement):
implements.setdefault(thing.implementor.identifier.name, []).append(thing.implementee.identifier.name)
elif isinstance(thing, WebIDL.IDLEnum):
enums[thing.identifier.name] = thing
#print interfaces
#print implements
pre_c = []
mid_c = []
mid_js = []
pre_c += [r'''
#include <emscripten.h>
''']
mid_c += [r'''
extern "C" {
''']
def emit_constructor(name):
global mid_js
mid_js += [r'''%s.prototype = %s;
%s.prototype.constructor = %s;
%s.prototype.__class__ = %s;
%s.__cache__ = {};
Module['%s'] = %s;
''' % (name, 'Object.create(%s.prototype)' % (implements[name][0] if implements.get(name) else 'WrapperObject'), name, name, name, name, name, name, name)]
mid_js += ['''
// Bindings utilities
function WrapperObject() {
}
''']
emit_constructor('WrapperObject')
mid_js += ['''
function getCache(__class__) {
return (__class__ || WrapperObject).__cache__;
}
Module['getCache'] = getCache;
function wrapPointer(ptr, __class__) {
var cache = getCache(__class__);
var ret = cache[ptr];
if (ret) return ret;
ret = Object.create((__class__ || WrapperObject).prototype);
ret.ptr = ptr;
return cache[ptr] = ret;
}
Module['wrapPointer'] = wrapPointer;
function castObject(obj, __class__) {
return wrapPointer(obj.ptr, __class__);
}
Module['castObject'] = castObject;
Module['NULL'] = wrapPointer(0);
function destroy(obj) {
if (!obj['__destroy__']) throw 'Error: Cannot destroy object. (Did you create it yourself?)';
obj['__destroy__']();
// Remove from cache, so the object can be GC'd and refs added onto it released
delete getCache(obj.__class__)[obj.ptr];
}
Module['destroy'] = destroy;
function compare(obj1, obj2) {
return obj1.ptr === obj2.ptr;
}
Module['compare'] = compare;
function getPointer(obj) {
return obj.ptr;
}
Module['getPointer'] = getPointer;
function getClass(obj) {
return obj.__class__;
}
Module['getClass'] = getClass;
// Converts a value into a C-style string.
var ensureString = (function() {
var stringCache = {};
function ensureString(value) {
if (typeof value == 'string') {
var cachedVal = stringCache[value];
if (cachedVal) return cachedVal;
var ret = allocate(intArrayFromString(value), 'i8', ALLOC_STACK);
stringCache[value] = ret;
return ret;
}
return value;
}
return ensureString;
})();
''']
mid_c += ['''
// Not using size_t for array indices as the values used by the javascript code are signed.
void array_bounds_check(const int array_size, const int array_idx) {
if (array_idx < 0 || array_idx >= array_size) {
EM_ASM_INT({
throw 'Array index ' + $0 + ' out of bounds: [0,' + $1 + ')';
}, array_idx, array_size);
}
}
''']
C_FLOATS = ['float', 'double']
def type_to_c(t, non_pointing=False):
#print 'to c ', t
t = t.replace(' (Wrapper)', '')
if t == 'Long':
return 'int'
elif t == 'UnsignedLong':
return 'unsigned int'
elif t == 'Short':
return 'short'
elif t == 'UnsignedShort':
return 'unsigned short'
elif t == 'Byte':
return 'char'
elif t == 'Octet':
return 'unsigned char'
elif t == 'Void':
return 'void'
elif t == 'String':
return 'char*'
elif t == 'Float':
return 'float'
elif t == 'Double':
return 'double'
elif t == 'Boolean':
return 'bool'
elif t == 'Any' or t == 'VoidPtr':
return 'void*'
elif t in interfaces:
return (interfaces[t].getExtendedAttribute('Prefix') or [''])[0] + t + ('' if non_pointing else '*')
else:
return t
def take_addr_if_nonpointer(m):
if m.getExtendedAttribute('Ref') or m.getExtendedAttribute('Value'):
return '&'
return ''
def deref_if_nonpointer(m):
if m.getExtendedAttribute('Ref') or m.getExtendedAttribute('Value'):
return '*'
return ''
def type_to_cdec(raw):
name = ret = type_to_c(raw.type.name, non_pointing=True)
if raw.getExtendedAttribute('Const'): ret = 'const ' + ret
if name not in interfaces: return ret
if raw.getExtendedAttribute('Ref'):
return ret + '&'
if raw.getExtendedAttribute('Value'):
return ret
return ret + '*'
def render_function(class_name, func_name, sigs, return_type, non_pointer, copy, operator, constructor, func_scope, call_content=None, const=False):
global mid_c, mid_js, js_impl_methods
#print 'renderfunc', class_name, func_name, sigs, return_type, constructor
bindings_name = class_name + '_' + func_name
min_args = min(sigs.keys())
max_args = max(sigs.keys())
c_names = {}
# JS
cache = ('getCache(%s)[this.ptr] = this;' % class_name) if constructor else ''
call_prefix = '' if not constructor else 'this.ptr = '
call_postfix = ''
if return_type != 'Void' and not constructor: call_prefix = 'return '
if not constructor:
if return_type in interfaces:
call_prefix += 'wrapPointer('
call_postfix += ', ' + return_type + ')'
elif return_type == 'String':
call_prefix += 'Pointer_stringify('
call_postfix += ')'
args = ['arg%d' % i for i in range(max_args)]
if not constructor:
body = ' var self = this.ptr;\n'
pre_arg = ['self']
else:
body = ''
pre_arg = []
for i in range(max_args):
# note: null has typeof object, but is ok to leave as is, since we are calling into asm code where null|0 = 0
body += " if (arg%d && typeof arg%d === 'object') arg%d = arg%d.ptr;\n" % (i, i, i, i)
body += " else arg%d = ensureString(arg%d);\n" % (i, i)
for i in range(min_args, max_args):
c_names[i] = 'emscripten_bind_%s_%d' % (bindings_name, i)
body += ' if (arg%d === undefined) { %s%s(%s)%s%s }\n' % (i, call_prefix, '_' + c_names[i], ', '.join(pre_arg + args[:i]), call_postfix, '' if 'return ' in call_prefix else '; ' + (cache or ' ') + 'return')
c_names[max_args] = 'emscripten_bind_%s_%d' % (bindings_name, max_args)
body += ' %s%s(%s)%s;\n' % (call_prefix, '_' + c_names[max_args], ', '.join(pre_arg + args), call_postfix)
if cache:
body += ' ' + cache + '\n'
mid_js += [r'''function%s(%s) {
%s
};''' % ((' ' + func_name) if constructor else '', ', '.join(args), body[:-1])]
# C
for i in range(min_args, max_args+1):
raw = sigs.get(i)
if raw is None: continue
sig = [arg.type.name for arg in raw]
c_arg_types = map(type_to_c, sig)
normal_args = ', '.join(['%s arg%d' % (c_arg_types[j], j) for j in range(i)])
if constructor:
full_args = normal_args
else:
full_args = type_to_c(class_name, non_pointing=True) + '* self' + ('' if not normal_args else ', ' + normal_args)
call_args = ', '.join(['%sarg%d' % ('*' if raw[j].getExtendedAttribute('Ref') else '', j) for j in range(i)])
if constructor:
call = 'new ' + type_to_c(class_name, non_pointing=True)
call += '(' + call_args + ')'
elif call_content is not None:
call = call_content
else:
call = 'self->' + func_name
call += '(' + call_args + ')'
if operator:
assert '=' in operator, 'can only do += *= etc. for now, all with "="'
cast_self = 'self'
if class_name != func_scope:
# this function comes from an ancestor class; for operators, we must cast it
cast_self = 'dynamic_cast<' + type_to_c(func_scope) + '>(' + cast_self + ')'
call = '(*%s %s %sarg0)' % (cast_self, operator, '*' if sig[0] in interfaces else '')
pre = ''
basic_return = 'return ' if constructor or return_type is not 'Void' else ''
return_prefix = basic_return
return_postfix = ''
if non_pointer:
return_prefix += '&';
if copy:
pre += ' static %s temp;\n' % type_to_c(return_type, non_pointing=True)
return_prefix += '(temp = '
return_postfix += ', &temp)'
c_return_type = type_to_c(return_type)
mid_c += [r'''
%s%s EMSCRIPTEN_KEEPALIVE %s(%s) {
%s %s%s%s;
}
''' % ('const ' if const else '', type_to_c(class_name) if constructor else c_return_type, c_names[i], full_args, pre, return_prefix, call, return_postfix)]
if not constructor:
if i == max_args:
dec_args = ', '.join(map(lambda j: type_to_cdec(raw[j]) + ' arg' + str(j), range(i)))
js_call_args = ', '.join(['%sarg%d' % (('(int)' if sig[j] in interfaces else '') + ('&' if raw[j].getExtendedAttribute('Ref') or raw[j].getExtendedAttribute('Value') else ''), j) for j in range(i)])
js_impl_methods += [r''' %s %s(%s) {
%sEM_ASM_%s({
var self = Module['getCache'](Module['%s'])[$0];
if (!self.hasOwnProperty('%s')) throw 'a JSImplementation must implement all functions, you forgot %s::%s.';
%sself['%s'](%s)%s;
}, (int)this%s);
}''' % (c_return_type, func_name, dec_args,
basic_return, 'INT' if c_return_type not in C_FLOATS else 'DOUBLE',
class_name,
func_name, class_name, func_name,
return_prefix,
func_name,
','.join(['$%d' % i for i in range(1, max_args + 1)]),
return_postfix,
(', ' if js_call_args else '') + js_call_args)]
for name, interface in interfaces.iteritems():
js_impl = interface.getExtendedAttribute('JSImplementation')
if not js_impl: continue
implements[name] = [js_impl[0]]
names = interfaces.keys()
names.sort(lambda x, y: 1 if implements.get(x) and implements[x][0] == y else (-1 if implements.get(y) and implements[y][0] == x else 0))
for name in names:
interface = interfaces[name]
mid_js += ['\n// ' + name + '\n']
mid_c += ['\n// ' + name + '\n']
global js_impl_methods
js_impl_methods = []
cons = interface.getExtendedAttribute('Constructor')
if type(cons) == list: raise Exception('do not use "Constructor", instead create methods with the name of the interface')
js_impl = interface.getExtendedAttribute('JSImplementation')
if js_impl:
js_impl = js_impl[0]
# Methods
seen_constructor = False # ensure a constructor, even for abstract base classes
for m in interface.members:
if m.identifier.name == name:
seen_constructor = True
break
if not seen_constructor:
mid_js += ['function %s() { throw "cannot construct a %s, no constructor in IDL" }\n' % (name, name)]
emit_constructor(name)
for m in interface.members:
if not m.isMethod(): continue
constructor = m.identifier.name == name
if not constructor:
parent_constructor = False
temp = m.parentScope
while temp.parentScope:
if temp.identifier.name == m.identifier.name:
parent_constructor = True
temp = temp.parentScope
if parent_constructor:
continue
if not constructor:
mid_js += [r'''
%s.prototype['%s'] = %s.prototype.%s = ''' % (name, m.identifier.name, name, m.identifier.name)]
sigs = {}
return_type = None
for ret, args in m.signatures():
if return_type is None:
return_type = ret.name
else:
assert return_type == ret.name, 'overloads must have the same return type'
for i in range(len(args)+1):
if i == len(args) or args[i].optional:
assert i not in sigs, 'overloading must differentiate by # of arguments (cannot have two signatures that differ by types but not by length)'
sigs[i] = args[:i]
render_function(name,
m.identifier.name, sigs, return_type,
m.getExtendedAttribute('Ref'),
m.getExtendedAttribute('Value'),
(m.getExtendedAttribute('Operator') or [None])[0],
constructor,
func_scope=m.parentScope.identifier.name,
const=m.getExtendedAttribute('Const'))
mid_js += [';\n']
if constructor:
emit_constructor(name)
for m in interface.members:
if not m.isAttr(): continue
attr = m.identifier.name
if m.type.isArray():
get_sigs = { 1: [Dummy({ 'type': WebIDL.BuiltinTypes[WebIDL.IDLBuiltinType.Types.long] })] }
set_sigs = { 2: [Dummy({ 'type': WebIDL.BuiltinTypes[WebIDL.IDLBuiltinType.Types.long] }),
Dummy({ 'type': m.type })] }
get_call_content = take_addr_if_nonpointer(m) + 'self->' + attr + '[arg0]'
set_call_content = 'self->' + attr + '[arg0] = ' + deref_if_nonpointer(m) + 'arg1'
if m.getExtendedAttribute('BoundsChecked'):
bounds_check = "array_bounds_check(sizeof(self->%s) / sizeof(self->%s[0]), arg0)" % (attr, attr)
get_call_content = "(%s, %s)" % (bounds_check, get_call_content)
set_call_content = "(%s, %s)" % (bounds_check, set_call_content)
else:
get_sigs = { 0: [] }
set_sigs = { 1: [Dummy({ 'type': m.type })] }
get_call_content = take_addr_if_nonpointer(m) + 'self->' + attr
set_call_content = 'self->' + attr + ' = ' + deref_if_nonpointer(m) + 'arg0'
get_name = 'get_' + attr
mid_js += [r'''
%s.prototype['%s'] = %s.prototype.%s = ''' % (name, get_name, name, get_name)]
render_function(name,
get_name, get_sigs, m.type.name,
None,
None,
None,
False,
func_scope=interface,
call_content=get_call_content,
const=m.getExtendedAttribute('Const'))
if not m.readonly:
set_name = 'set_' + attr
mid_js += [r'''
%s.prototype['%s'] = %s.prototype.%s = ''' % (name, set_name, name, set_name)]
render_function(name,
set_name, set_sigs, 'Void',
None,
None,
None,
False,
func_scope=interface,
call_content=set_call_content,
const=m.getExtendedAttribute('Const'))
if not interface.getExtendedAttribute('NoDelete'):
mid_js += [r'''
%s.prototype['__destroy__'] = %s.prototype.__destroy__ = ''' % (name, name)]
render_function(name,
'__destroy__', { 0: [] }, 'Void',
None,
None,
None,
False,
func_scope=interface,
call_content='delete self')
# Emit C++ class implementation that calls into JS implementation
if js_impl:
pre_c += [r'''
class %s : public %s {
public:
%s
};
''' % (name, type_to_c(js_impl, non_pointing=True), '\n'.join(js_impl_methods))]
deferred_js = []
for name, enum in enums.iteritems():
mid_c += ['\n// ' + name + '\n']
deferred_js += ['\n', '// ' + name + '\n']
for value in enum.values():
function_id = "%s_%s" % (name, value.split('::')[-1])
mid_c += [r'''%s EMSCRIPTEN_KEEPALIVE emscripten_enum_%s() {
return %s;
}
''' % (name, function_id, value)]
symbols = value.split('::')
if len(symbols) == 1:
identifier = symbols[0]
deferred_js += ["Module['%s'] = _emscripten_enum_%s();\n" % (identifier, function_id)]
elif len(symbols) == 2:
[namespace, identifier] = symbols
if namespace in interfaces:
# namespace is a class
deferred_js += ["Module['%s']['%s'] = _emscripten_enum_%s();\n" % \
(namespace, identifier, function_id)]
else:
# namespace is a namespace, so the enums get collapsed into the top level namespace.
deferred_js += ["Module['%s'] = _emscripten_enum_%s();\n" % (identifier, function_id)]
else:
raise Exception("Illegal enum value %s" % value)
mid_c += ['\n}\n\n']
mid_js += ['''
(function() {
function setupEnums() {
%s
}
if (Module['calledRun']) setupEnums();
else addOnPreMain(setupEnums);
})();
''' % '\n '.join(deferred_js)]
# Write
c = open(output_base + '.cpp', 'w')
for x in pre_c: c.write(x)
for x in mid_c: c.write(x)
c.close()
js = open(output_base + '.js', 'w')
for x in mid_js: js.write(x)
js.close()