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Sufu

[H]ard|Gawd
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Sep 3, 2006
Messages
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This is a very simple error, but I don't understand how it can happen. I have two variables named sipRes, both are contained in separate If... statements. First one is a bool, second is a pointer (PyObject*), but MSVC9 compiler is throwing me an error at what (I think) should be valid C++ code:

107: error: C2440: '=' : cannot convert from 'bool' to 'PyObject *'
Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast

Line 107 is when I set the result of sipConvertFromNewType (which returns a PyObject*) to sipRes, which was declared as PyObject*, but the compiler seems to be ignoring it and thinks it's a bool instead. What is wrong here?? Am I missing a compiler flag?

This is mostly autogenerated code, so it's not as simple as naming it sipRes2.

Below is part of my Makefile, and the offending function code

Code: 
CC = cl
CXX = cl
LINK = link
CPPFLAGS = -DNDEBUG -DWIN32 -DQT_LARGEFILE_SUPPORT -DMBCS -DQT_DLL -DQT_NO_DEBUG -I. -I$(VOICEMANAGERDIR)\include -I$(OPALDIR)\include -I$(PTLIBDIR)\include -I$(QTDIR)\include\QtCore -IC:\Python27\include -IC:\Qt\2010.05\qt\mkspecs\default -IC:\Qt\2010.05\qt\include\voicemanager -IC:\Qt\2010.05\qt\include\opal -IC:\Qt\2010.05\qt\include\ptlib -IC:\Qt\2010.05\qt\include
CFLAGS = -Zi -nologo -Zm200 -Zc:wchar_t -Zc:forScope -O2 -MD -W3
CXXFLAGS = -EHsc -Zi -nologo -Zm200 -Zc:wchar_t -Zc:forScope -O2 -MD -W3 -w34100 -w34189
LFLAGS = /DEBUG /PDB:pyvoicemanager.pdb /NOLOGO /DLL /MANIFEST /MANIFESTFILE:$(TARGET).manifest /SUBSYSTEM:WINDOWS "/MANIFESTDEPENDENCY:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' publicKeyToken='6595b64144ccf1df' language='*' processorArchitecture='*'" /INCREMENTAL:NO
LIBS = /LIBPATH:$(VOICEMANAGERDIR)\lib /LIBPATH:$(OPALDIR)\lib /LIBPATH:$(PTLIBDIR)\lib /LIBPATH:C:\Python27\libs /LIBPATH:C:\Qt\2010.05\qt\lib python27.lib voicemanager.lib opal.lib ptlib.lib
MOC = C:\Qt\2010.05\qt\bin\\moc.exe
.SUFFIXES: .c .cpp .cc .cxx .C

Code: 
static PyObject *meth_OpalTransportAddress_GetIpAndPort(PyObject *sipSelf, PyObject *sipArgs, PyObject *sipKwds)
{
    PyObject *sipParseErr = NULL;

    {
        PIPSocket::Address * a0;
        WORD a1;
        OpalTransportAddress *sipCpp;

        if (sipParseKwdArgs(&sipParseErr, sipArgs, sipKwds, NULL, NULL, "B", &sipSelf, sipType_OpalTransportAddress, &sipCpp))
        {
            PBoolean sipRes; // first sipRes var
            a0 = new PIPSocket::Address();

            Py_BEGIN_ALLOW_THREADS
            sipRes = sipCpp->GetIpAndPort(*a0,a1);
            Py_END_ALLOW_THREADS

            return sipBuildResult(0,"(bNt)",sipRes,a0,sipType_PIPSocket_Address,NULL,a1);
        }
    }

    {
        OpalTransportAddress *sipCpp;

        if (sipParseKwdArgs(&sipParseErr, sipArgs, sipKwds, NULL, NULL, "B", &sipSelf, sipType_OpalTransportAddress, &sipCpp))
        {
            PyObject * sipRes = 0; //second sipRes var
            sipErrorState sipError = sipErrorNone;

#line 101 "C:\\iPhoneDev\\voicemanager\\sip\\opal/OpalTransport.sip"
    PIPSocketAddressAndPort * ipPort = new PIPSocketAddressAndPort;

    Py_BEGIN_ALLOW_THREADS
    sipCpp->GetIpAndPort(*ipPort);
    Py_END_ALLOW_THREADS

    if ((sipRes=sipConvertFromNewType(ipPort, sipType_PIPSocketAddressAndPort, NULL) == NULL))
    {
        sipError=sipErrorFail;
        PyErr_SetString(PyExc_RuntimeError, "Failed to convert C++ Object to PyObject");
    }
#line 280 "C:\\iPhoneDev\\voicemanager\\sip\\build\\opal\\release/sippyopalOpalTransportAddress.cpp"

            if (sipError == sipErrorFail)
                return 0;

            if (sipError == sipErrorNone)
            {
            return sipRes;
            }

            sipAddException(sipError, &sipParseErr);
        }
    }

    /* Raise an exception if the arguments couldn't be parsed. */
    sipNoMethod(sipParseErr, sipName_OpalTransportAddress, sipName_GetIpAndPort, NULL);

    return NULL;
}
 
Post the entire file here or on pastebin, its impossible to figure out whats going on when we can't see everything.
 
I figured out the problem. the other bool sipRes var threw me off and I read too much into it.

I was doing this: if ((pyObj=sipConvertFromNewType(ipPort, sipType_PIPSocketAddressAndPort, NULL) == NULL)) which is assigning a bool value to a PyObject pointer (true if NULL else false), instead of:

if ((pyObj=sipConvertFromNewType(ipPort, sipType_PIPSocketAddressAndPort, NULL)) == NULL)

which is checking for NULL!
 
look at:
Code: 
if ((sipRes=sipConvertFromNewType(ipPort, sipType_PIPSocketAddressAndPort, NULL) == NULL))

then check the c++ order of operations, and think about what is happening
 
ye olde parentheses problem, happens to everyone
 
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