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 specs.stdapi as stdapi


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


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):
        for type, name in struct.members:
            self.visit(type)
        print 'static void _write__%s(const %s &value) {' % (struct.tag, struct.expr)
        print '    static const char * members[%u] = {' % (len(struct.members),)
        for type, name,  in struct.members:
            print '        "%s",' % (name,)
        print '    };'
        print '    static const trace::StructSig sig = {'
        print '       %u, "%s", %u, members' % (struct.id, struct.name, len(struct.members))
        print '    };'
        print '    trace::localWriter.beginStruct(&sig);'
        for type, name in struct.members:
            self.serializer.visit(type, 'value.%s' % (name,))
        print '    trace::localWriter.endStruct();'
        print '}'
        print

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

    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):
        print 'static void _write__%s(int selector, const %s & 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, 'static_cast<%s>(value)' % (type,))
            print '        break;'
        print '    }'
        print '}'
        print


class ValueSerializer(stdapi.Visitor):
    '''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 string.kind == 'String':
            cast = 'const char *'
        elif string.kind == 'WString':
            cast = 'const wchar_t *'
        else:
            assert False
        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' % string.length
        else:
            length = ''
        print '    trace::localWriter.write%s(%s%s);' % (string.kind, instance, length)

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

    def visitStruct(self, struct, instance):
        print '    _write__%s(%s);' % (struct.tag, instance)

    def visitArray(self, array, instance):
        length = '__c' + array.type.tag
        index = '__i' + array.type.tag
        print '    if (%s) {' % instance
        print '        size_t %s = %s;' % (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.visit(array.type, '(%s)[%s]' % (instance, index))
        print '            trace::localWriter.endElement();'
        print '        }'
        print '        trace::localWriter.endArray();'
        print '    } else {'
        print '        trace::localWriter.writeNull();'
        print '    }'

    def visitBlob(self, blob, instance):
        print '    trace::localWriter.writeBlob(%s, %s);' % (instance, 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.writeOpaque((const void *)%s);' % instance

    def visitObjPointer(self, pointer, instance):
        print '    trace::localWriter.writeOpaque((const void *)%s);' % instance

    def visitLinearPointer(self, pointer, instance):
        print '    trace::localWriter.writeOpaque((const void *)%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.writeOpaque((const void *)%s);' % instance

    def visitInterface(self, interface, instance):
        print '    trace::localWriter.writeOpaque((const void *)&%s);' % instance

    def visitPolymorphic(self, polymorphic, instance):
        print '    _write__%s(%s, %s);' % (polymorphic.tag, polymorphic.switchExpr, instance)


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 visitVoid(self, void):
        raise NotImplementedError

    def visitLinearPointer(self, void):
        pass

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


class ValueWrapper(stdapi.Traverser):
    '''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 type, name in struct.members:
            self.visit(type, "(%s).%s" % (instance, name))

    def visitArray(self, array, instance):
        print "    if (%s) {" % instance
        print "        for (size_t _i = 0, _s = %s; _i < _s; ++_i) {" % array.length
        self.visit(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):
        print "    if (%s) {" % instance
        self.visit(pointer.type, "*" + instance)
        print "    }"
    
    def visitInterface(self, interface, instance):
        assert instance.startswith('*')
        instance = instance[1:]
        print "    if (%s) {" % instance
        print "        %s = new %s(%s);" % (instance, getWrapperInterfaceName(interface), instance)
        print "    }"
    
    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 visitArray(self, array, instance):
        if self.allocated or isinstance(instance, stdapi.Interface):
            return ValueWrapper.visitArray(self, array, instance)
        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 visitInterface(self, interface, instance):
        assert instance.startswith('*')
        instance = instance[1:]
        print r'    if (%s) {' % instance
        print r'        const %s *pWrapper = static_cast<const %s*>(%s);' % (getWrapperInterfaceName(interface), getWrapperInterfaceName(interface), instance)
        print r'        if (pWrapper && pWrapper->m_dwMagic == 0xd8365d6c) {'
        print r'            %s = pWrapper->m_pInstance;' % (instance,)
        print r'        } else {'
        print r'            os::log("apitrace: warning: %%s: unexpected %%s pointer\n", __FUNCTION__, "%s");' % interface.name
        print r'        }'
        print r'    }'


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

    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 trace_api(self, api):
        self.api = api

        self.header(api)

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

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

        # Interfaces wrapers
        interfaces = api.getAllInterfaces()
        map(self.declareWrapperInterface, interfaces)
        map(self.implementWrapperInterface, interfaces)
        print

        # Function wrappers
        map(self.traceFunctionDecl, api.functions)
        map(self.traceFunctionImpl, api.functions)
        print

        self.footer(api)

    def header(self, api):
        pass

    def footer(self, api):
        pass

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

        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, function.id, function.name, len(function.args), function.name)
        print

    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
        self.traceFunctionImplBody(function)
        if function.type is not stdapi.Void:
            self.wrapRet(function, "__result")
            print '    return __result;'
        print '}'
        print

    def traceFunctionImplBody(self, function):
        print '    unsigned __call = trace::localWriter.beginEnter(&__%s_sig);' % (function.name,)
        for arg in function.args:
            if not arg.output:
                self.unwrapArg(function, arg)
                self.serializeArg(function, arg)
        print '    trace::localWriter.endEnter();'
        self.invokeFunction(function)
        print '    trace::localWriter.beginLeave(__call);'
        for arg in function.args:
            if arg.output:
                self.serializeArg(function, arg)
                self.wrapArg(function, arg)
        if function.type is not stdapi.Void:
            self.serializeRet(function, "__result")
        print '    trace::localWriter.endLeave();'

    def invokeFunction(self, function, prefix='__', suffix=''):
        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 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):
        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 unwrapRet(self, function, instance):
        self.unwrapValue(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 declareWrapperInterface(self, interface):
        print "class %s : public %s " % (getWrapperInterfaceName(interface), interface.name)
        print "{"
        print "public:"
        print "    %s(%s * pInstance);" % (getWrapperInterfaceName(interface), interface.name)
        print "    virtual ~%s();" % getWrapperInterfaceName(interface)
        print
        for method in interface.iterMethods():
            print "    " + method.prototype() + ";"
        print
        self.declareWrapperInterfaceVariables(interface)
        print "};"
        print

    def declareWrapperInterfaceVariables(self, interface):
        #print "private:"
        print "    DWORD m_dwMagic;"
        print "    %s * m_pInstance;" % (interface.name,)

    def implementWrapperInterface(self, interface):
        print '%s::%s(%s * pInstance) {' % (getWrapperInterfaceName(interface), getWrapperInterfaceName(interface), interface.name)
        print '    m_dwMagic = 0xd8365d6c;'
        print '    m_pInstance = pInstance;'
        print '}'
        print
        print '%s::~%s() {' % (getWrapperInterfaceName(interface), getWrapperInterfaceName(interface))
        print '}'
        print
        for base, method in interface.iterBaseMethods():
            self.implementWrapperInterfaceMethod(interface, base, method)
        print

    def implementWrapperInterfaceMethod(self, interface, base, method):
        print method.prototype(getWrapperInterfaceName(interface) + '::' + method.name) + ' {'
        if method.type is not stdapi.Void:
            print '    %s __result;' % method.type
    
        self.implementWrapperInterfaceMethodBody(interface, base, method)
    
        if method.type is not stdapi.Void:
            print '    return __result;'
        print '}'
        print

    def implementWrapperInterfaceMethodBody(self, interface, base, method):
        print '    static const char * __args[%u] = {%s};' % (len(method.args) + 1, ', '.join(['"this"'] + ['"%s"' % arg.name for arg in method.args]))
        print '    static const trace::FunctionSig __sig = {%u, "%s", %u, __args};' % (method.id, interface.name + '::' + method.name, len(method.args) + 1)
        print '    unsigned __call = trace::localWriter.beginEnter(&__sig);'
        print '    trace::localWriter.beginArg(0);'
        print '    trace::localWriter.writeOpaque((const void *)m_pInstance);'
        print '    trace::localWriter.endArg();'

        from specs.winapi import REFIID
        from specs.stdapi import Pointer, Opaque, Interface

        riid = None
        for arg in method.args:
            if not arg.output:
                self.unwrapArg(method, arg)
                self.serializeArg(method, arg)
                if arg.type is REFIID:
                    riid = arg
        print '    trace::localWriter.endEnter();'
        
        self.invokeMethod(interface, base, method)

        print '    trace::localWriter.beginLeave(__call);'
        for arg in method.args:
            if arg.output:
                self.serializeArg(method, arg)
                self.wrapArg(method, arg)
                if riid is not None and isinstance(arg.type, Pointer):
                    if isinstance(arg.type.type, Opaque):
                        self.wrapIid(interface, method, riid, arg)
                    else:
                        assert isinstance(arg.type.type, Pointer)
                        assert isinstance(arg.type.type.type, Interface)

        if method.type is not stdapi.Void:
            print '    trace::localWriter.beginReturn();'
            self.serializeValue(method.type, "__result")
            print '    trace::localWriter.endReturn();'
            self.wrapValue(method.type, '__result')
        print '    trace::localWriter.endLeave();'
        if method.name == 'Release':
            assert method.type is not stdapi.Void
            print '    if (!__result)'
            print '        delete this;'

    def wrapIid(self, interface, method, riid, out):
            print '    if (%s && *%s) {' % (out.name, out.name)
            print '        if (*%s == m_pInstance) {' % (out.name,)
            print '            *%s = this;' % (out.name,)
            print '        }'
            for iface in self.api.getAllInterfaces():
                print r'        else if (%s == IID_%s) {' % (riid.name, iface.name)
                print r'            *%s = new Wrap%s((%s *) *%s);' % (out.name, iface.name, iface.name, out.name)
                print r'        }'
            print r'        else {'
            print r'            os::log("apitrace: warning: %s::%s: unknown IID {0x%08lX,0x%04X,0x%04X,{0x%02X,0x%02X,0x%02X,0x%02X,0x%02X,0x%02X,0x%02X,0x%02X}}\n",'
            print r'                    "%s", "%s",' % (interface.name, method.name)
            print r'                    %s.Data1, %s.Data2, %s.Data3,' % (riid.name, riid.name, riid.name)
            print r'                    %s.Data4[0],' % (riid.name,)
            print r'                    %s.Data4[1],' % (riid.name,)
            print r'                    %s.Data4[2],' % (riid.name,)
            print r'                    %s.Data4[3],' % (riid.name,)
            print r'                    %s.Data4[4],' % (riid.name,)
            print r'                    %s.Data4[5],' % (riid.name,)
            print r'                    %s.Data4[6],' % (riid.name,)
            print r'                    %s.Data4[7]);' % (riid.name,)
            print r'        }'
            print '    }'

    def invokeMethod(self, interface, base, method):
        if method.type is stdapi.Void:
            result = ''
        else:
            result = '__result = '
        print '    %sstatic_cast<%s *>(m_pInstance)->%s(%s);' % (result, base, method.name, ', '.join([str(arg.name) for arg in method.args]))
    
    def emit_memcpy(self, dest, src, length):
        print '        unsigned __call = trace::localWriter.beginEnter(&trace::memcpy_sig);'
        print '        trace::localWriter.beginArg(0);'
        print '        trace::localWriter.writeOpaque(%s);' % dest
        print '        trace::localWriter.endArg();'
        print '        trace::localWriter.beginArg(1);'
        print '        trace::localWriter.writeBlob(%s, %s);' % (src, length)
        print '        trace::localWriter.endArg();'
        print '        trace::localWriter.beginArg(2);'
        print '        trace::localWriter.writeUInt(%s);' % length
        print '        trace::localWriter.endArg();'
        print '        trace::localWriter.endEnter();'
        print '        trace::localWriter.beginLeave(__call);'
        print '        trace::localWriter.endLeave();'