chore: import upstream snapshot with attribution

modules/python/src2/cv2_util.hpp

@@ -0,0 +1,138 @@
+#ifndef CV2_UTIL_HPP
+#define CV2_UTIL_HPP
+
+#include "cv2.hpp"
+#include "opencv2/core.hpp"
+#include "opencv2/core/utils/tls.hpp"
+#include <vector>
+#include <string>
+
+//======================================================================================================================
+
+bool isPythonBindingsDebugEnabled();
+void emit_failmsg(PyObject * exc, const char *msg);
+int failmsg(const char *fmt, ...);
+PyObject* failmsgp(const char *fmt, ...);
+
+//======================================================================================================================
+
+class PyAllowThreads
+{
+public:
+    PyAllowThreads() : _state(PyEval_SaveThread()) {}
+    ~PyAllowThreads()
+    {
+        PyEval_RestoreThread(_state);
+    }
+private:
+    PyThreadState* _state;
+};
+
+class PyEnsureGIL
+{
+public:
+    PyEnsureGIL() : _state(PyGILState_Ensure()) {}
+    ~PyEnsureGIL()
+    {
+        PyGILState_Release(_state);
+    }
+private:
+    PyGILState_STATE _state;
+};
+
+/**
+ * Light weight RAII wrapper for `PyObject*` owning references.
+ * In comparison to C++11 `std::unique_ptr` with custom deleter, it provides
+ * implicit conversion functions that might be useful to initialize it with
+ * Python functions those returns owning references through the `PyObject**`
+ * e.g. `PyErr_Fetch` or directly pass it to functions those want to borrow
+ * reference to object (doesn't extend object lifetime) e.g. `PyObject_Str`.
+ */
+class PySafeObject
+{
+public:
+    PySafeObject() : obj_(NULL) {}
+
+    explicit PySafeObject(PyObject* obj) : obj_(obj) {}
+
+    ~PySafeObject()
+    {
+        Py_CLEAR(obj_);
+    }
+
+    operator PyObject*()
+    {
+        return obj_;
+    }
+
+    operator PyObject**()
+    {
+        return &obj_;
+    }
+
+    operator bool() {
+        return obj_ != nullptr;
+    }
+
+    PyObject* release()
+    {
+        PyObject* obj = obj_;
+        obj_ = NULL;
+        return obj;
+    }
+
+private:
+    PyObject* obj_;
+
+    // Explicitly disable copy operations
+    PySafeObject(const PySafeObject*); // = delete
+    PySafeObject& operator=(const PySafeObject&); // = delete
+};
+
+//======================================================================================================================
+
+extern PyObject* opencv_error;
+
+void pyRaiseCVException(const cv::Exception &e);
+
+#define ERRWRAP2(expr) \
+try \
+{ \
+    PyAllowThreads allowThreads; \
+    expr; \
+} \
+catch (const cv::Exception &e) \
+{ \
+    pyRaiseCVException(e); \
+    return 0; \
+} \
+catch (const std::exception &e) \
+{ \
+    PyErr_SetString(opencv_error, e.what()); \
+    return 0; \
+} \
+catch (...) \
+{ \
+    PyErr_SetString(opencv_error, "Unknown C++ exception from OpenCV code"); \
+    return 0; \
+}
+
+//======================================================================================================================
+
+extern cv::TLSData<std::vector<std::string> > conversionErrorsTLS;
+
+inline void pyPrepareArgumentConversionErrorsStorage(std::size_t size)
+{
+    std::vector<std::string>& conversionErrors = conversionErrorsTLS.getRef();
+    conversionErrors.clear();
+    conversionErrors.reserve(size);
+}
+
+void pyRaiseCVOverloadException(const std::string& functionName);
+void pyPopulateArgumentConversionErrors();
+
+//======================================================================================================================
+
+PyObject *pycvRedirectError(PyObject*, PyObject *args, PyObject *kw);
+
+#endif // CV2_UTIL_HPP