path: root/wrappers/trace.py

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"""Common trace code generation."""


# Adjust path
import os.path
import sys
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))

import itertools

import specs.stdapi as stdapi


def getWrapperInterfaceName(interface):
    return "Wrap" + interface.expr


debug = False


class ComplexValueSerializer(stdapi.OnceVisitor):
    '''Type visitors which generates serialization functions for
    complex types.
    
    Simple types are serialized inline.
    '''

    def __init__(self, serializer):
        stdapi.OnceVisitor.__init__(self)
        self.serializer = serializer

    def visitVoid(self, literal):
        pass

    def visitLiteral(self, literal):
        pass

    def visitString(self, string):
        pass

    def visitConst(self, const):
        self.visit(const.type)

    def visitStruct(self, struct):
        # Write array with structure's member names
        numMembers = len(struct.members)
        if numMembers:
            # Ensure member array has nonzero length to avoid MSVC error C2466
            memberNames = '_struct%s_members' % (struct.tag,)
            print 'static const char * %s[%u] = {' % (memberNames, numMembers)
            for type, name,  in struct.members:
                if name is None:
                    print '    "",'
                else:
                    print '    "%s",' % (name,)
            print '};'
        else:
            sys.stderr.write('warning: %s has no members\n' % struct.name)
            memberNames = 'nullptr'

        # Write structure's signature
        print 'static const trace::StructSig _struct%s_sig = {' % (struct.tag,)
        if struct.name is None:
            structName = '""'
        else:
            structName = '"%s"' % struct.name
        print '    %u, %s, %u, %s' % (struct.id, structName, numMembers, memberNames)
        print '};'
        print

    def visitArray(self, array):
        self.visit(array.type)

    def visitAttribArray(self, array):
        pass

    def visitBlob(self, array):
        pass

    def visitEnum(self, enum):
        print 'static const trace::EnumValue _enum%s_values[] = {' % (enum.tag)
        for value in enum.values:
            print '    {"%s", %s},' % (value, value)
        print '};'
        print
        print 'static const trace::EnumSig _enum%s_sig = {' % (enum.tag)
        print '    %u, %u, _enum%s_values' % (enum.id, len(enum.values), enum.tag)
        print '};'
        print

    def visitBitmask(self, bitmask):
        print 'static const trace::BitmaskFlag _bitmask%s_flags[] = {' % (bitmask.tag)
        for value in bitmask.values:
            print '    {"%s", %s},' % (value, value)
        print '};'
        print
        print 'static const trace::BitmaskSig _bitmask%s_sig = {' % (bitmask.tag)
        print '    %u, %u, _bitmask%s_flags' % (bitmask.id, len(bitmask.values), bitmask.tag)
        print '};'
        print

    def visitPointer(self, pointer):
        self.visit(pointer.type)

    def visitIntPointer(self, pointer):
        pass

    def visitObjPointer(self, pointer):
        self.visit(pointer.type)

    def visitLinearPointer(self, pointer):
        self.visit(pointer.type)

    def visitHandle(self, handle):
        self.visit(handle.type)

    def visitReference(self, reference):
        self.visit(reference.type)

    def visitAlias(self, alias):
        self.visit(alias.type)

    def visitOpaque(self, opaque):
        pass

    def visitInterface(self, interface):
        pass

    def visitPolymorphic(self, polymorphic):
        if not polymorphic.contextLess:
            return
        print 'static void _write__%s(int selector, %s const & value) {' % (polymorphic.tag, polymorphic.expr)
        print '    switch (selector) {'
        for cases, type in polymorphic.iterSwitch():
            for case in cases:
                print '    %s:' % case
            self.serializer.visit(type, '(%s)(value)' % (type,))
            print '        break;'
        print '    }'
        print '}'
        print


class ValueSerializer(stdapi.Visitor, stdapi.ExpanderMixin):
    '''Visitor which generates code to serialize any type.
    
    Simple types are serialized inline here, whereas the serialization of
    complex types is dispatched to the serialization functions generated by
    ComplexValueSerializer visitor above.
    '''

    def visitLiteral(self, literal, instance):
        print '    trace::localWriter.write%s(%s);' % (literal.kind, instance)

    def visitString(self, string, instance):
        if not string.wide:
            cast = 'const char *'
            suffix = 'String'
        else:
            cast = 'const wchar_t *'
            suffix = 'WString'
        if cast != string.expr:
            # reinterpret_cast is necessary for GLubyte * <=> char *
            instance = 'reinterpret_cast<%s>(%s)' % (cast, instance)
        if string.length is not None:
            length = ', %s' % self.expand(string.length)
        else:
            length = ''
        print '    trace::localWriter.write%s(%s%s);' % (suffix, instance, length)

    def visitConst(self, const, instance):
        self.visit(const.type, instance)

    def visitStruct(self, struct, instance):
        print '    trace::localWriter.beginStruct(&_struct%s_sig);' % (struct.tag,)
        for member in struct.members:
            self.visitMember(member, instance)
        print '    trace::localWriter.endStruct();'

    def visitArray(self, array, instance):
        length = '_c' + array.type.tag
        index = '_i' + array.type.tag
        array_length = self.expand(array.length)
        print '    if (%s) {' % instance
        print '        size_t %s = %s > 0 ? %s : 0;' % (length, array_length, array_length)
        print '        trace::localWriter.beginArray(%s);' % length
        print '        for (size_t %s = 0; %s < %s; ++%s) {' % (index, index, length, index)
        print '            trace::localWriter.beginElement();'
        self.visitElement(index, array.type, '(%s)[%s]' % (instance, index))
        print '            trace::localWriter.endElement();'
        print '        }'
        print '        trace::localWriter.endArray();'
        print '    } else {'
        print '        trace::localWriter.writeNull();'
        print '    }'

    def visitAttribArray(self, array, instance):
        # For each element, decide if it is a key or a value (which depends on the previous key).
        # If it is a value, store it as the right type - usually int, some bitfield, or some enum.
        # It is currently assumed that an unknown key means that it is followed by an int value.

        # determine the array length which must be passed to writeArray() up front
        count = '_c' + array.baseType.tag
        print '    {'
        print '    int %s;' % count
        print '    for (%(c)s = 0; %(array)s && %(array)s[%(c)s] != %(terminator)s; %(c)s += 2) {' \
              % {'c': count, 'array': instance, 'terminator': array.terminator}
        if array.hasKeysWithoutValues:
            print '        switch (int(%(array)s[%(c)s])) {' % {'array': instance, 'c': count}
            for key, valueType in array.valueTypes:
                if valueType is None:
                    print '        case %s:' % key
            print '            %s--;' % count # the next value is a key again and checked if it's the terminator
            print '            break;'
            print '        }'
        print '    }'
        print '    %(c)s += %(array)s ? 1 : 0;' % {'c': count, 'array': instance}
        print '    trace::localWriter.beginArray(%s);' % count

        # for each key / key-value pair write the key and the value, if the key requires one

        index = '_i' + array.baseType.tag
        print '    for (int %(i)s = 0; %(i)s < %(count)s; %(i)s++) {' % {'i': index, 'count': count}
        print '        trace::localWriter.beginElement();'
        self.visit(array.baseType, "%(array)s[%(i)s]" % {'array': instance, 'i': index})
        print '        trace::localWriter.endElement();'
        print '        if (%(i)s + 1 >= %(count)s) {' % {'i': index, 'count': count}
        print '            break;'
        print '        }'
        print '        switch (int(%(array)s[%(i)s++])) {' % {'array': instance, 'i': index}
        # write generic value the usual way
        for key, valueType in array.valueTypes:
            if valueType is not None:
                print '        case %s:' % key
                print '            trace::localWriter.beginElement();'
                self.visitElement(index, valueType, '(%(array)s)[%(i)s]' % {'array': instance, 'i': index})
                print '            trace::localWriter.endElement();'
                print '            break;'
        # known key with no value, just decrease the index so we treat the next value as a key
        if array.hasKeysWithoutValues:
            for key, valueType in array.valueTypes:
                if valueType is None:
                    print '        case %s:' % key
            print '            %s--;' % index
            print '            break;'
        # unknown key, write an int value
        print '        default:'
        print '            trace::localWriter.beginElement();'
        print '            os::log("apitrace: warning: %s: unknown key 0x%04X, interpreting value as int\\n", ' + \
                           '__FUNCTION__, int(%(array)s[%(i)s - 1]));'  % {'array': instance, 'i': index}
        print '            trace::localWriter.writeSInt(%(array)s[%(i)s]);' % {'array': instance, 'i': index}
        print '            trace::localWriter.endElement();'
        print '            break;'
        print '        }'
        print '    }'
        print '    trace::localWriter.endArray();'
        print '    }'


    def visitBlob(self, blob, instance):
        print '    trace::localWriter.writeBlob(%s, %s);' % (instance, self.expand(blob.size))

    def visitEnum(self, enum, instance):
        print '    trace::localWriter.writeEnum(&_enum%s_sig, %s);' % (enum.tag, instance)

    def visitBitmask(self, bitmask, instance):
        print '    trace::localWriter.writeBitmask(&_bitmask%s_sig, %s);' % (bitmask.tag, instance)

    def visitPointer(self, pointer, instance):
        print '    if (%s) {' % instance
        print '        trace::localWriter.beginArray(1);'
        print '        trace::localWriter.beginElement();'
        self.visit(pointer.type, "*" + instance)
        print '        trace::localWriter.endElement();'
        print '        trace::localWriter.endArray();'
        print '    } else {'
        print '        trace::localWriter.writeNull();'
        print '    }'

    def visitIntPointer(self, pointer, instance):
        print '    trace::localWriter.writePointer((uintptr_t)%s);' % instance

    def visitObjPointer(self, pointer, instance):
        print '    trace::localWriter.writePointer((uintptr_t)%s);' % instance

    def visitLinearPointer(self, pointer, instance):
        print '    trace::localWriter.writePointer((uintptr_t)%s);' % instance

    def visitReference(self, reference, instance):
        self.visit(reference.type, instance)

    def visitHandle(self, handle, instance):
        self.visit(handle.type, instance)

    def visitAlias(self, alias, instance):
        self.visit(alias.type, instance)

    def visitOpaque(self, opaque, instance):
        print '    trace::localWriter.writePointer((uintptr_t)%s);' % instance

    def visitInterface(self, interface, instance):
        assert False

    def visitPolymorphic(self, polymorphic, instance):
        if polymorphic.contextLess:
            print '    _write__%s(%s, %s);' % (polymorphic.tag, polymorphic.switchExpr, instance)
        else:
            switchExpr = self.expand(polymorphic.switchExpr)
            print '    switch (%s) {' % switchExpr
            for cases, type in polymorphic.iterSwitch():
                for case in cases:
                    print '    %s:' % case
                caseInstance = instance
                if type.expr is not None:
                    caseInstance = 'static_cast<%s>(%s)' % (type, caseInstance)
                self.visit(type, caseInstance)
                print '        break;'
            if polymorphic.defaultType is None:
                print r'    default:'
                print r'        os::log("apitrace: warning: %%s: unexpected polymorphic case %%i\n", __FUNCTION__, (int)%s);' % (switchExpr,)
                print r'        trace::localWriter.writeNull();'
                print r'        break;'
            print '    }'


class WrapDecider(stdapi.Traverser):
    '''Type visitor which will decide wheter this type will need wrapping or not.
    
    For complex types (arrays, structures), we need to know this before hand.
    '''

    def __init__(self):
        self.needsWrapping = False

    def visitLinearPointer(self, void):
        pass

    def visitObjPointer(self, interface):
        self.needsWrapping = True


class ValueWrapper(stdapi.Traverser, stdapi.ExpanderMixin):
    '''Type visitor which will generate the code to wrap an instance.
    
    Wrapping is necessary mostly for interfaces, however interface pointers can
    appear anywhere inside complex types.
    '''

    def visitStruct(self, struct, instance):
        for member in struct.members:
            self.visitMember(member, instance)

    def visitArray(self, array, instance):
        array_length = self.expand(array.length)
        print "    if (%s) {" % instance
        print "        for (size_t _i = 0, _s = %s; _i < _s; ++_i) {" % array_length
        self.visitElement('_i', array.type, instance + "[_i]")
        print "        }"
        print "    }"

    def visitPointer(self, pointer, instance):
        print "    if (%s) {" % instance
        self.visit(pointer.type, "*" + instance)
        print "    }"
    
    def visitObjPointer(self, pointer, instance):
        elem_type = pointer.type.mutable()
        if isinstance(elem_type, stdapi.Interface):
            self.visitInterfacePointer(elem_type, instance)
        elif isinstance(elem_type, stdapi.Alias) and isinstance(elem_type.type, stdapi.Interface):
            self.visitInterfacePointer(elem_type.type, instance)
        else:
            # All interfaces should at least implement IUnknown
            print "    WrapIUnknown::_wrap(__FUNCTION__, (IUnknown **) &%s);" % (instance,)
    
    def visitInterface(self, interface, instance):
        raise NotImplementedError

    def visitInterfacePointer(self, interface, instance):
        print "    Wrap%s::_wrap(__FUNCTION__, &%s);" % (interface.name, instance)
    
    def visitPolymorphic(self, type, instance):
        # XXX: There might be polymorphic values that need wrapping in the future
        raise NotImplementedError


class ValueUnwrapper(ValueWrapper):
    '''Reverse of ValueWrapper.'''

    allocated = False

    def visitStruct(self, struct, instance):
        if not self.allocated:
            # Argument is constant. We need to create a non const
            print '    {'
            print "        %s * _t = static_cast<%s *>(alloca(sizeof *_t));" % (struct, struct)
            print '        *_t = %s;' % (instance,)
            assert instance.startswith('*')
            print '        %s = _t;' % (instance[1:],)
            instance = '*_t'
            self.allocated = True
            try:
                return ValueWrapper.visitStruct(self, struct, instance)
            finally:
                print '    }'
        else:
            return ValueWrapper.visitStruct(self, struct, instance)

    def visitArray(self, array, instance):
        if self.allocated or isinstance(instance, stdapi.Interface):
            return ValueWrapper.visitArray(self, array, instance)
        array_length = self.expand(array.length)
        elem_type = array.type.mutable()
        print "    if (%s && %s) {" % (instance, array_length)
        print "        %s * _t = static_cast<%s *>(alloca(%s * sizeof *_t));" % (elem_type, elem_type, array_length)
        print "        for (size_t _i = 0, _s = %s; _i < _s; ++_i) {" % array_length
        print "            _t[_i] = %s[_i];" % instance 
        self.allocated = True
        self.visit(array.type, "_t[_i]")
        print "        }"
        print "        %s = _t;" % instance
        print "    }"

    def visitInterfacePointer(self, interface, instance):
        print r'    Wrap%s::_unwrap(__FUNCTION__, &%s);' % (interface.name, instance)


def _getInterfaceHierarchy(allIfaces, baseIface, result):
    for iface in allIfaces:
        if iface.base is baseIface:
            _getInterfaceHierarchy(allIfaces, iface, result)
            result.append(iface)

def getInterfaceHierarchy(allIfaces, baseIface):
    result = []
    _getInterfaceHierarchy(allIfaces, baseIface, result)
    return result


class Tracer:
    '''Base class to orchestrate the code generation of API tracing.'''

    # 0-3 are reserved to memcpy, malloc, free, and realloc
    __id = 4

    def __init__(self):
        self.api = None

    def serializerFactory(self):
        '''Create a serializer.
        
        Can be overriden by derived classes to inject their own serialzer.
        '''

        return ValueSerializer()

    def traceApi(self, api):
        self.api = api

        self.header(api)

        # Includes
        for module in api.modules:
            for header in module.headers:
                print header
        print

        # Generate the serializer functions
        types = api.getAllTypes()
        visitor = ComplexValueSerializer(self.serializerFactory())
        map(visitor.visit, types)
        print

        # Interfaces wrapers
        self.traceInterfaces(api)

        # Function wrappers
        self.interface = None
        self.base = None
        for function in api.getAllFunctions():
            self.traceFunctionDecl(function)
        for function in api.getAllFunctions():
            try:
                self.traceFunctionImpl(function)
            except:
                sys.stderr.write("error: %s: exception\n" % function.name)
                raise
        print

        self.footer(api)

    def header(self, api):
        print '#ifdef _WIN32'
        print '#  include <malloc.h> // alloca'
        print '#  ifndef alloca'
        print '#    define alloca _alloca'
        print '#  endif'
        print '#else'
        print '#  include <alloca.h> // alloca'
        print '#endif'
        print
        print
        print 'static std::map<void *, void *> g_WrappedObjects;'

    def footer(self, api):
        pass

    def traceFunctionDecl(self, function):
        # Per-function declarations

        if not function.internal:
            if function.args:
                print 'static const char * _%s_args[%u] = {%s};' % (function.name, len(function.args), ', '.join(['"%s"' % arg.name for arg in function.args]))
            else:
                print 'static const char ** _%s_args = NULL;' % (function.name,)
            print 'static const trace::FunctionSig _%s_sig = {%u, "%s", %u, _%s_args};' % (function.name, self.getFunctionSigId(), function.sigName(), len(function.args), function.name)
            print

    def getFunctionSigId(self):
        id = Tracer.__id
        Tracer.__id += 1
        return id

    def isFunctionPublic(self, function):
        return True

    def traceFunctionImpl(self, function):
        if self.isFunctionPublic(function):
            print 'extern "C" PUBLIC'
        else:
            print 'extern "C" PRIVATE'
        print function.prototype() + ' {'
        if function.type is not stdapi.Void:
            print '    %s _result;' % function.type

        for arg in function.args:
            if not arg.output:
                self.unwrapArg(function, arg)

        self.traceFunctionImplBody(function)

        # XXX: wrapping should go here, but before we can do that we'll need to protect g_WrappedObjects with its own mutex

        if function.type is not stdapi.Void:
            print '    return _result;'

        print '}'
        print

    def traceFunctionImplBody(self, function):
        if not function.internal:
            print '    unsigned _call = trace::localWriter.beginEnter(&_%s_sig);' % (function.name,)
            for arg in function.args:
                if not arg.output:
                    self.serializeArg(function, arg)
            print '    trace::localWriter.endEnter();'
        self.invokeFunction(function)
        if not function.internal:
            print '    trace::localWriter.beginLeave(_call);'
            print '    if (%s) {' % self.wasFunctionSuccessful(function)
            for arg in function.args:
                if arg.output:
                    self.serializeArg(function, arg)
                    self.wrapArg(function, arg)
            print '    }'
            if function.type is not stdapi.Void:
                self.serializeRet(function, "_result")
            if function.type is not stdapi.Void:
                self.wrapRet(function, "_result")
            print '    trace::localWriter.endLeave();'

    def invokeFunction(self, function):
        self.doInvokeFunction(function)

    def doInvokeFunction(self, function, prefix='_', suffix=''):
        # Same as invokeFunction() but called both when trace is enabled or disabled.
        if function.type is stdapi.Void:
            result = ''
        else:
            result = '_result = '
        dispatch = prefix + function.name + suffix
        print '    %s%s(%s);' % (result, dispatch, ', '.join([str(arg.name) for arg in function.args]))

    def wasFunctionSuccessful(self, function):
        if function.type is stdapi.Void:
            return 'true'
        if str(function.type) == 'HRESULT':
            return 'SUCCEEDED(_result)'
        return 'true'

    def serializeArg(self, function, arg):
        print '    trace::localWriter.beginArg(%u);' % (arg.index,)
        self.serializeArgValue(function, arg)
        print '    trace::localWriter.endArg();'

    def serializeArgValue(self, function, arg):
        self.serializeValue(arg.type, arg.name)

    def wrapArg(self, function, arg):
        assert not isinstance(arg.type, stdapi.ObjPointer)

        from specs.winapi import REFIID
        riid = None
        for other_arg in function.args:
            if not other_arg.output and other_arg.type is REFIID:
                riid = other_arg
        if riid is not None \
           and riid.name != 'EmulatedInterface' \
           and isinstance(arg.type, stdapi.Pointer) \
           and isinstance(arg.type.type, stdapi.ObjPointer):
            self.wrapIid(function, riid, arg)
            return

        self.wrapValue(arg.type, arg.name)

    def unwrapArg(self, function, arg):
        self.unwrapValue(arg.type, arg.name)

    def serializeRet(self, function, instance):
        print '    trace::localWriter.beginReturn();'
        self.serializeValue(function.type, instance)
        print '    trace::localWriter.endReturn();'

    def serializeValue(self, type, instance):
        serializer = self.serializerFactory()
        serializer.visit(type, instance)

    def wrapRet(self, function, instance):
        self.wrapValue(function.type, instance)

    def needsWrapping(self, type):
        visitor = WrapDecider()
        visitor.visit(type)
        return visitor.needsWrapping

    def wrapValue(self, type, instance):
        if self.needsWrapping(type):
            visitor = ValueWrapper()
            visitor.visit(type, instance)

    def unwrapValue(self, type, instance):
        if self.needsWrapping(type):
            visitor = ValueUnwrapper()
            visitor.visit(type, instance)

    def traceInterfaces(self, api):
        interfaces = api.getAllInterfaces()
        if not interfaces:
            return

        print r'#include "guids.hpp"'
        print

        # Helper functions to wrap/unwrap interface pointers
        print r'static inline bool'
        print r'hasChildInterface(REFIID riid, IUnknown *pUnknown) {'
        print r'    IUnknown *pObj = NULL;'
        print r'    HRESULT hr = pUnknown->QueryInterface(riid, (VOID **)&pObj);'
        print r'    if (FAILED(hr)) {'
        print r'        return false;'
        print r'    }'
        print r'    assert(pObj);'
        print r'    pObj->Release();'
        print r'    return pUnknown == pObj;'
        print r'}'
        print
        print r'static inline const void *'
        print r'getVtbl(const void *pvObj) {'
        print r'    return pvObj ? *(const void **)pvObj : NULL;'
        print r'}'
        print
        print r'static void'
        print r'warnVtbl(const void *pVtbl) {'
        print r'    HMODULE hModule = 0;'
        print r'    BOOL bRet = GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |'
        print r'                                  GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,'
        print r'                                  (LPCTSTR)pVtbl,'
        print r'                                  &hModule);'
        print r'    assert(bRet);'
        print r'    if (bRet) {'
        print r'        char szModule[MAX_PATH];'
        print r'        DWORD dwRet = GetModuleFileNameA(hModule, szModule, sizeof szModule);'
        print r'        assert(dwRet);'
        print r'        if (dwRet) {'
        print r'            DWORD dwOffset = (UINT_PTR)pVtbl - (UINT_PTR)hModule;'
        print r'            os::log("apitrace: warning: pVtbl = %p (%s!+0x%0lx)\n", pVtbl, szModule, dwOffset);'
        print r'        }'
        print r'    }'
        print r'}'
        print 

        map(self.declareWrapperInterface, interfaces)

        self.implementIidWrapper(api)
        
        map(self.implementWrapperInterface, interfaces)
        print

    def declareWrapperInterface(self, interface):
        wrapperInterfaceName = getWrapperInterfaceName(interface)
        print "class %s : public %s " % (wrapperInterfaceName, interface.name)
        print "{"
        print "private:"
        print "    %s(%s * pInstance);" % (wrapperInterfaceName, interface.name)
        print "    ~%s(); // Not implemented" % wrapperInterfaceName
        print "public:"
        print "    static %s* _create(const char *entryName, %s * pInstance);" % (wrapperInterfaceName, interface.name)
        print "    static void _wrap(const char *entryName, %s ** ppInstance);" % (interface.name,)
        print "    static void _unwrap(const char *entryName, %s ** pInstance);" % (interface.name,)
        print

        methods = list(interface.iterMethods())
        for method in methods:
            print "    " + method.prototype() + " override;"
        print

        for type, name, value in self.enumWrapperInterfaceVariables(interface):
            print '    %s %s;' % (type, name)
        print

        print r'private:'
        print r'    void _dummy(unsigned i) const {'
        print r'        os::log("error: %%s: unexpected virtual method %%i of instance pvObj=%%p pWrapper=%%p pVtbl=%%p\n", "%s", i, m_pInstance, this, m_pVtbl);' % interface.name
        print r'        warnVtbl(m_pVtbl);'
        print r'        warnVtbl(getVtbl(m_pInstance));'
        print r'        trace::localWriter.flush();'
        print r'        os::abort();'
        print r'    }'
        print
        for i in range(len(methods), 64):
            print r'    virtual void _dummy%i(void) const { _dummy(%i); }' % (i, i)
        print

        print "};"
        print

    def enumWrapperInterfaceVariables(self, interface):
        return [
            ("DWORD", "m_dwMagic", "0xd8365d6c"),
            ("%s *" % interface.name, "m_pInstance", "pInstance"),
            ("const void *", "m_pVtbl", "getVtbl(pInstance)"),
            ("UINT", "m_NumMethods", len(list(interface.iterBaseMethods()))),
        ] 

    def implementWrapperInterface(self, iface):
        self.interface = iface

        wrapperInterfaceName = getWrapperInterfaceName(iface)

        # Private constructor
        print '%s::%s(%s * pInstance) {' % (wrapperInterfaceName, wrapperInterfaceName, iface.name)
        for type, name, value in self.enumWrapperInterfaceVariables(iface):
            if value is not None:
                print '    %s = %s;' % (name, value)
        print '}'
        print

        # Public constructor
        print '%s *%s::_create(const char *entryName, %s * pInstance) {' % (wrapperInterfaceName, wrapperInterfaceName, iface.name)
        print r'    Wrap%s *pWrapper = new Wrap%s(pInstance);' % (iface.name, iface.name)
        if debug:
            print r'    os::log("%%s: created %s pvObj=%%p pWrapper=%%p pVtbl=%%p\n", entryName, pInstance, pWrapper, pWrapper->m_pVtbl);' % iface.name
        print r'    g_WrappedObjects[pInstance] = pWrapper;'
        print r'    return pWrapper;'
        print '}'
        print

        baseMethods = list(iface.iterBaseMethods())
        for base, method in baseMethods:
            self.base = base
            self.implementWrapperInterfaceMethod(iface, base, method)

        print

        # Wrap pointer
        ifaces = self.api.getAllInterfaces()
        print r'void'
        print r'%s::_wrap(const char *entryName, %s **ppObj) {' % (wrapperInterfaceName, iface.name)
        print r'    if (!ppObj) {'
        print r'        return;'
        print r'    }'
        print r'    %s *pObj = *ppObj;' % (iface.name,)
        print r'    if (!pObj) {'
        print r'        return;'
        print r'    }'
        print r'    assert(hasChildInterface(IID_%s, pObj));' % iface.name
        print r'    std::map<void *, void *>::const_iterator it = g_WrappedObjects.find(pObj);'
        print r'    if (it != g_WrappedObjects.end()) {'
        print r'        Wrap%s *pWrapper = (Wrap%s *)it->second;' % (iface.name, iface.name)
        print r'        assert(pWrapper);'
        print r'        assert(pWrapper->m_dwMagic == 0xd8365d6c);'
        print r'        assert(pWrapper->m_pInstance == pObj);'
        print r'        if (pWrapper->m_pVtbl == getVtbl(pObj) &&'
        print r'            pWrapper->m_NumMethods >= %s) {' % len(baseMethods)
        if debug:
            print r'            os::log("%s: fetched pvObj=%p pWrapper=%p pVtbl=%p\n", entryName, pObj, pWrapper, pWrapper->m_pVtbl);'
        print r'            assert(hasChildInterface(IID_%s, pWrapper->m_pInstance));' % iface.name
        print r'            *ppObj = pWrapper;'
        print r'            return;'
        print r'        } else {'
        if debug:
            print r'            os::log("%s::Release: deleted pvObj=%%p pWrapper=%%p pVtbl=%%p\n", pWrapper->m_pInstance, pWrapper, pWrapper->m_pVtbl);' % iface.name
        print r'            g_WrappedObjects.erase(pObj);'
        print r'        }'
        print r'    }'
        for childIface in getInterfaceHierarchy(ifaces, iface):
            print r'    if (hasChildInterface(IID_%s, pObj)) {' % (childIface.name,)
            print r'        *ppObj = Wrap%s::_create(entryName, static_cast<%s *>(pObj));' % (childIface.name, childIface.name)
            print r'        return;'
            print r'    }'
        print r'    *ppObj = Wrap%s::_create(entryName, pObj);' % iface.name
        print r'}'
        print

        # Unwrap pointer
        print r'void'
        print r'%s::_unwrap(const char *entryName, %s **ppObj) {' % (wrapperInterfaceName, iface.name)
        print r'    if (!ppObj || !*ppObj) {'
        print r'        return;'
        print r'    }'
        print r'    const %s *pWrapper = static_cast<const %s*>(*ppObj);' % (wrapperInterfaceName, getWrapperInterfaceName(iface))
        print r'    if (pWrapper && pWrapper->m_dwMagic == 0xd8365d6c) {'
        print r'        *ppObj = pWrapper->m_pInstance;'
        print r'    } else {'
        print r'        os::log("apitrace: warning: %%s: unexpected %%s pointer %%p\n", entryName, "%s", *ppObj);' % iface.name
        print r'        trace::localWriter.flush();'
        print r'    }'
        print r'}'
        print

    def implementWrapperInterfaceMethod(self, interface, base, method):
        wrapperInterfaceName = getWrapperInterfaceName(interface)

        print method.prototype(wrapperInterfaceName + '::' + method.name) + ' {'

        if False:
            print r'    os::log("%%s(%%p -> %%p)\n", "%s", this, m_pInstance);' % (wrapperInterfaceName + '::' + method.name)

        if method.type is not stdapi.Void:
            print '    %s _result;' % method.type
    
        print '    %s *_this = static_cast<%s *>(m_pInstance);' % (base, base)
        for arg in method.args:
            if not arg.output:
                self.unwrapArg(method, arg)

        self.implementWrapperInterfaceMethodBody(interface, base, method)

        # XXX: wrapping should go here, but before we can do that we'll need to protect g_WrappedObjects with its own mutex

        if method.type is not stdapi.Void:
            print '    return _result;'

        print '}'
        print

    def implementWrapperInterfaceMethodBody(self, interface, base, method):
        assert not method.internal

        sigName = interface.name + '::' + method.sigName()
        if method.overloaded:
            # Once the method signature name goes into a trace, we'll need to
            # support it indefinetely, so log them so one can make sure nothing
            # weird gets baked in
            sys.stderr.write('note: overloaded method %s\n' % (sigName,))

        numArgs = len(method.args) + 1
        print '    static const char * _args[%u] = {%s};' % (numArgs, ', '.join(['"this"'] + ['"%s"' % arg.name for arg in method.args]))
        print '    static const trace::FunctionSig _sig = {%u, "%s", %u, _args};' % (self.getFunctionSigId(), sigName, numArgs)

        print '    unsigned _call = trace::localWriter.beginEnter(&_sig);'
        print '    trace::localWriter.beginArg(0);'
        print '    trace::localWriter.writePointer((uintptr_t)m_pInstance);'
        print '    trace::localWriter.endArg();'
        for arg in method.args:
            if not arg.output:
                self.serializeArg(method, arg)
        print '    trace::localWriter.endEnter();'
        
        self.invokeMethod(interface, base, method)

        print '    trace::localWriter.beginLeave(_call);'

        print '    if (%s) {' % self.wasFunctionSuccessful(method)
        for arg in method.args:
            if arg.output:
                self.serializeArg(method, arg)
                self.wrapArg(method, arg)
        print '    }'

        if method.type is not stdapi.Void:
            self.serializeRet(method, '_result')
        if method.type is not stdapi.Void:
            self.wrapRet(method, '_result')

        if method.name == 'Release':
            assert method.type is not stdapi.Void
            print r'    if (!_result) {'
            print r'        // NOTE: Must not delete the wrapper here.  See'
            print r'        // https://github.com/apitrace/apitrace/issues/462'
            print r'    }'
        
        print '    trace::localWriter.endLeave();'

    def implementIidWrapper(self, api):
        ifaces = api.getAllInterfaces()

        print r'static void'
        print r'warnIID(const char *entryName, REFIID riid, void *pvObj, const char *reason) {'
        print r'    os::log("apitrace: warning: %s: %s IID %s\n",'
        print r'            entryName, reason,'
        print r'            getGuidName(riid));'
        print r'    const void * pVtbl = getVtbl(pvObj);'
        print r'    warnVtbl(pVtbl);'
        print r'}'
        print 
        print r'static void'
        print r'wrapIID(const char *entryName, REFIID riid, void * * ppvObj) {'
        print r'    if (!ppvObj || !*ppvObj) {'
        print r'        return;'
        print r'    }'
        for iface in ifaces:
            print r'    if (riid == IID_%s) {' % (iface.name,)
            print r'        Wrap%s::_wrap(entryName, (%s **) ppvObj);' % (iface.name, iface.name)
            print r'        return;'
            print r'    }'
        print r'    warnIID(entryName, riid, *ppvObj, "unsupported");'
        print r'}'
        print

    def wrapIid(self, function, riid, out):
        # Cast output arg to `void **` if necessary
        out_name = out.name
        obj_type = out.type.type.type
        if not obj_type is stdapi.Void:
            assert isinstance(obj_type, stdapi.Interface)
            out_name = 'reinterpret_cast<void * *>(%s)' % out_name

        print r'    if (%s && *%s) {' % (out.name, out.name)
        functionName = function.name
        else_ = ''
        if self.interface is not None:
            functionName = self.interface.name + '::' + functionName
            print r'        if (*%s == m_pInstance &&' % (out_name,)
            print r'            (%s)) {' % ' || '.join('%s == IID_%s' % (riid.name, iface.name) for iface in self.interface.iterBases())
            print r'            *%s = this;' % (out_name,)
            print r'        }'
            else_ = 'else '
        print r'        %s{' % else_
        print r'             wrapIID("%s", %s, %s);' % (functionName, riid.name, out_name)
        print r'        }'
        print r'    }'

    def invokeMethod(self, interface, base, method):
        if method.type is stdapi.Void:
            result = ''
        else:
            result = '_result = '
        print '    %s_this->%s(%s);' % (result, method.name, ', '.join([str(arg.name) for arg in method.args]))
    
    def emit_memcpy(self, ptr, size):
        print '    trace::fakeMemcpy(%s, %s);' % (ptr, size)
    
    def fake_call(self, function, args):
        print '        {'
        print '            unsigned _fake_call = trace::localWriter.beginEnter(&_%s_sig, true);' % (function.name,)
        for arg, instance in zip(function.args, args):
            assert not arg.output
            print '            trace::localWriter.beginArg(%u);' % (arg.index,)
            self.serializeValue(arg.type, instance)
            print '            trace::localWriter.endArg();'
        print '            trace::localWriter.endEnter();'
        print '            trace::localWriter.beginLeave(_fake_call);'
        print '            trace::localWriter.endLeave();'
        print '        }'