pep384impl.cpp: Make the implementation more stateless

The pep384impl.h part is quite readable and stateless concerning the
state of Py_LIMITED_API.
The pep384impl.cpp part is stateful, which means there is no clear
separation between parts of the implementation.

This had led to unnecessary confusion in the past. To avoid that in
future, the #ifdef status of Py_LIMITED_API will no longer be carried
over multiple sections.

Also, checks which are for the limited API only are no longer executed
by default.

Further, PyDict_GetItem is replaced by PyDict_GetItemWithError, where
we do not expect a real error.

Change-Id: Ia51e551216c76f82b701ebc45c40e2d1412cabf5
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 41 insertions, 36 deletions

diff --git a/sources/shiboken2/libshiboken/pep384impl.cpp b/sources/shiboken2/libshiboken/pep384impl.cpp
index 9f51034f3..c04848eb3 100644
--- a/sources/shiboken2/libshiboken/pep384impl.cpp
+++ b/sources/shiboken2/libshiboken/pep384impl.cpp
@@ -50,26 +50,19 @@ extern "C"
 /*
  * The documentation is located in pep384impl_doc.rst
  */
-
-/*****************************************************************************
- *
- * Support for object.h
- *
- */
-
+#if PY_VERSION_HEX < 0x03000000
+#define IS_PY2
+#endif // PY_VERSION_HEX < 0x03000000
 /*
  * Here is the verification code for PyTypeObject.
  * We create a type object and check if its fields
  * appear at the right offsets.
  */
+#ifdef Py_LIMITED_API
 
 #define make_dummy_int(x)   (x * sizeof(void *))
 #define make_dummy(x)       (reinterpret_cast<void *>(make_dummy_int(x)))
 
-#ifdef Py_LIMITED_API
-datetime_struc *PyDateTimeAPI = nullptr;
-#endif
-
 static PyObject *
 dummy_func(PyObject * /* self */, PyObject * /* args */)
 {
@@ -180,18 +173,18 @@ check_PyTypeObject_valid()
     Py_DECREF(probe_tp_mro);
 }
 
-
-#ifdef Py_LIMITED_API
-
 #if PY_VERSION_HEX < PY_ISSUE33738_SOLVED
 #include "pep384_issue33738.cpp"
 #endif
 
+#endif // Py_LIMITED_API
+
 /*****************************************************************************
  *
  * Support for unicodeobject.h
  *
  */
+#ifdef Py_LIMITED_API
 
 char *
 _PepUnicode_AsString(PyObject *str)
@@ -214,7 +207,7 @@ _PepUnicode_AsString(PyObject *str)
             Py_FatalError("Error in " AT);
     }
     PyObject *bytesStr = PyUnicode_AsEncodedString(str, "utf8", nullptr);
-    PyObject *entry = PyDict_GetItem(cstring_dict, bytesStr);
+    PyObject *entry = PyDict_GetItemWithError(cstring_dict, bytesStr);
     if (entry == nullptr) {
         int e = PyDict_SetItem(cstring_dict, bytesStr, bytesStr);
         if (e != 0)
@@ -225,12 +218,14 @@ _PepUnicode_AsString(PyObject *str)
         Py_DECREF(bytesStr);
     return PyBytes_AsString(entry);
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for longobject.h
  *
  */
+#ifdef Py_LIMITED_API
 
 /*
  * This is the original Python function _PyLong_AsInt() from longobject.c .
@@ -255,12 +250,15 @@ _PepLong_AsInt(PyObject *obj)
     }
     return int(result);
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for pydebug.h
  *
  */
+#ifdef Py_LIMITED_API
+
 static PyObject *sys_flags = nullptr;
 
 int
@@ -299,12 +297,14 @@ Pep_GetVerboseFlag()
     }
     return verbose_flag;
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for code.h
  *
  */
+#ifdef Py_LIMITED_API
 
 int
 PepCode_Get(PyCodeObject *co, const char *name)
@@ -321,12 +321,16 @@ PepCode_Get(PyCodeObject *co, const char *name)
     }
     return ret;
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for datetime.h
  *
  */
+#ifdef Py_LIMITED_API
+
+datetime_struc *PyDateTimeAPI = nullptr;
 
 static PyTypeObject *dt_getCheck(const char *name)
 {
@@ -398,12 +402,14 @@ PyTime_FromTime(int hour, int min, int sec, int usec)
     return PyObject_CallFunction((PyObject *)PyDateTimeAPI->TimeType,
                                  (char *)"(iiii)", hour, min, sec, usec);
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for pythonrun.h
  *
  */
+#ifdef Py_LIMITED_API
 
 // Flags are ignored in these simple helpers.
 PyObject *
@@ -423,7 +429,7 @@ PyRun_String(const char *str, int start, PyObject *globals, PyObject *locals)
 
 // This is only a simple local helper that returns a computed variable.
 // Used also in Python 2.
-#if defined(Py_LIMITED_API) || PY_VERSION_HEX < 0x03000000
+#if defined(Py_LIMITED_API) || defined(IS_PY2)
 static PyObject *
 PepRun_GetResult(const char *command)
 {
@@ -440,15 +446,14 @@ PepRun_GetResult(const char *command)
     Py_DECREF(d);
     return res;
 }
-#endif // Py_LIMITED_API || Python 2
-
-#ifdef Py_LIMITED_API
+#endif // defined(Py_LIMITED_API) || defined(IS_PY2)
 
 /*****************************************************************************
  *
  * Support for classobject.h
  *
  */
+#ifdef Py_LIMITED_API
 
 PyTypeObject *PepMethod_TypePtr = nullptr;
 
@@ -489,12 +494,14 @@ PyMethod_Self(PyObject *im)
     Py_DECREF(ret);
     return ret;
 }
+#endif // Py_LIMITED_API
 
 /*****************************************************************************
  *
  * Support for funcobject.h
  *
  */
+#ifdef Py_LIMITED_API
 
 PyObject *
 PepFunction_Get(PyObject *ob, const char *name)
@@ -517,7 +524,6 @@ static PyTypeObject *getFunctionType(void)
         "from types import FunctionType as result\n";
     return reinterpret_cast<PyTypeObject *>(PepRun_GetResult(prog));
 }
-
 #endif // Py_LIMITED_API || Python 2
 
 /*****************************************************************************
@@ -527,7 +533,7 @@ static PyTypeObject *getFunctionType(void)
  */
 
 // PYSIDE-803, PYSIDE-813: We need that GIL-free version from Python 2.7.12 .
-#if PY_VERSION_HEX < 0x03000000
+#ifdef IS_PY2
 
 /* Variant of PyDict_GetItem() that doesn't suppress exceptions.
    This returns NULL *with* an exception set if an exception occurred.
@@ -558,15 +564,13 @@ PyDict_GetItemWithError(PyObject *op, PyObject *key)
     }
     return ep->me_value;
 }
-
-#endif
+#endif // IS_PY2
 
 /*****************************************************************************
  *
  * Extra support for signature.cpp
  *
  */
-
 #ifdef Py_LIMITED_API
 
 PyTypeObject *PepStaticMethod_TypePtr = nullptr;
@@ -601,7 +605,7 @@ PyStaticMethod_New(PyObject *callable)
 }
 #endif // Py_LIMITED_API
 
-#if PY_VERSION_HEX < 0x03000000
+#ifdef IS_PY2
 PyTypeObject *PepMethodDescr_TypePtr = nullptr;
 
 static PyTypeObject *
@@ -611,7 +615,7 @@ getMethodDescrType(void)
         "result = type(str.split)\n";
     return reinterpret_cast<PyTypeObject *>(PepRun_GetResult(prog));
 }
-#endif
+#endif // IS_PY2
 
 /*****************************************************************************
  *
@@ -640,9 +644,9 @@ PepType_GetNameStr(PyTypeObject *type)
 
 #ifdef Py_LIMITED_API
 // We keep these definitions local, because they don't work in Python 2.
-#define PyUnicode_GET_LENGTH(op)    PyUnicode_GetLength((PyObject *)(op))
-#define PyUnicode_READ_CHAR(u, i)   PyUnicode_ReadChar((PyObject *)(u), (i))
-#endif
+# define PyUnicode_GET_LENGTH(op)    PyUnicode_GetLength((PyObject *)(op))
+# define PyUnicode_READ_CHAR(u, i)   PyUnicode_ReadChar((PyObject *)(u), (i))
+#endif // Py_LIMITED_API
 
 PyObject *
 _Pep_PrivateMangle(PyObject *self, PyObject *name)
@@ -652,7 +656,7 @@ _Pep_PrivateMangle(PyObject *self, PyObject *name)
      * This function is modelled after _Py_Mangle, but is optimized
      * a little for our purpose.
      */
-#if PY_VERSION_HEX < 0X03000000
+#ifdef IS_PY2
     const char *namestr = PyString_AsString(name);
     if (namestr == nullptr || namestr[0] != '_' || namestr[1] != '_') {
         Py_INCREF(name);
@@ -679,7 +683,7 @@ _Pep_PrivateMangle(PyObject *self, PyObject *name)
         Py_INCREF(name);
         return name;
     }
-#endif
+#endif // IS_PY2
     Shiboken::AutoDecRef privateobj(PyObject_GetAttr(
         reinterpret_cast<PyObject *>(Py_TYPE(self)), Shiboken::PyMagicName::name()));
 #ifndef Py_LIMITED_API
@@ -718,7 +722,7 @@ _Pep_PrivateMangle(PyObject *self, PyObject *name)
     if (amount > big_stack)
         free(resbuf);
     return result;
-#endif  // Py_LIMITED_API
+#endif // else Py_LIMITED_API
 }
 
 /*****************************************************************************
@@ -749,17 +753,18 @@ init_PepRuntime()
 void
 Pep384_Init()
 {
-    check_PyTypeObject_valid();
     init_PepRuntime();
 #ifdef Py_LIMITED_API
+    check_PyTypeObject_valid();
     Pep_GetVerboseFlag();
     PepMethod_TypePtr = getMethodType();
     PepFunction_TypePtr = getFunctionType();
     PepStaticMethod_TypePtr = getStaticMethodType();
-#endif
-#if PY_VERSION_HEX < 0x03000000
+#endif // Py_LIMITED_API
+
+#ifdef IS_PY2
     PepMethodDescr_TypePtr = getMethodDescrType();
-#endif
+#endif // IS_PY2
 }
 
 } // extern "C"