Function LoadPythonAPI

gcore/gdalpython.cpp:169–801

Load the subset of the Python C API that we need */

/** Load the subset of the Python C API that we need */
static bool LoadPythonAPI()
{
    static int nInit = -1;
    if (nInit >= 0)
        return nInit == TRUE;
    nInit = FALSE;

#ifdef LOAD_NOCHECK_WITH_NAME
    static LibraryHandle libHandle = nullptr;
    const char *pszPythonSO = CPLGetConfigOption("PYTHONSO", nullptr);
#if defined(HAVE_DLFCN_H) && !defined(_WIN32)

    // First try in the current process in case the python symbols would
    // be already loaded
    libHandle = dlopen(nullptr, RTLD_LAZY);
    if (libHandle != nullptr &&
        dlsym(libHandle, "Py_SetProgramName") != nullptr)
    {
        CPLDebug("GDAL", "Current process has python symbols loaded");
    }
    else
    {
        if (libHandle)
            dlclose(libHandle);
        libHandle = nullptr;
    }

    // Then try the user provided shared object name
    if (libHandle == nullptr && pszPythonSO != nullptr)
    {
        // coverity[tainted_string]
        libHandle = dlopen(pszPythonSO, RTLD_NOW | RTLD_GLOBAL);
        if (libHandle == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Cannot load %s",
                     pszPythonSO);
            return false;
        }
        if (dlsym(libHandle, "Py_SetProgramName") == nullptr)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Cannot find Py_SetProgramName symbol in %s", pszPythonSO);
            return false;
        }
    }

    // Then try the PYTHONSO_DEFAULT if defined at compile time
#ifdef PYTHONSO_DEFAULT
    if (libHandle == nullptr)
    {
        libHandle = dlopen(PYTHONSO_DEFAULT, RTLD_NOW | RTLD_GLOBAL);
        if (!libHandle)
        {
            CPLDebug("GDAL", "%s found", PYTHONSO_DEFAULT);
        }
    }
#endif