chore(PythonQtPythonInclude, build/python.prf): Report error if using Python 2.x

Author: jcfr

build/python.prf

@@ -25,14 +25,9 @@ PYTHON_VERSION_MINOR=$$section(PYTHON_VERSION, ., 1, 1)
   message(Using Python version $${PYTHON_VERSION})
 }
 
-
-# Python 2.x has problems:
-# 1) https://wiki.gentoo.org/wiki/Project:Python/Strict_aliasing
-# 2) deprecated implicit cast of string literals to char*
+# Python 3.x is required
 equals(PYTHON_VERSION_MAJOR, 2) {
-   gcc:QMAKE_CXXFLAGS *= -fno-strict-aliasing -Wno-write-strings
-   # Qt 5.4 adds this option, but this is not compatible with the Python API
-   msvc: QMAKE_CXXFLAGS -= -Zc:strictStrings
+  error("Python >= 3.x is required")
 }
 
 contains(PKGCONFIG, "python.*"){
@@ -73,13 +68,6 @@ contains(PKGCONFIG, "python.*"){
      error("PYTHON_PATH must be set to correct folder with \\libs and \\include subfolders ")
   }
 
-  #We need to destinguish 64-bit build to add a workaround option
-  #The only known problematic case is MinGW with external (MSVC-built) Python2
-  mingw:equals(PYTHON_VERSION_MAJOR, 2): isEmpty(QMAKE_TARGET.arch):system(\
-  $$system_quote($$system_path($${PYTHON_PATH}/python.exe)) -c \
-  $$system_quote(import sysconfig;exit(0 if 0 <= sysconfig.get_platform().find(\'win-amd64\') else 1))\
-  ):DEFINES += MS_WIN64
-
   INCLUDEPATH += $$shell_path($${PYTHON_PATH}/include)
 
   LIBS += $$shell_path(-L$${PYTHON_PATH}/libs)

src/PythonQtPythonInclude.h

@@ -117,18 +117,14 @@
 #undef PYTHONQT_RESTORE_KEYWORDS
 #endif
 
-#if PY_MAJOR_VERSION >= 3
+#if PY_MAJOR_VERSION < 3
+#error "PythonQt requires Python >= 3.x"
+#endif
+
 #define PY3K
 // Helper defines to facilitate porting
 #define PyString_FromString PyUnicode_FromString
 
-#else
-// Defines to use Python 3 names in Python 2 code
-#define PyBytes_Type      PyString_Type
-#define PyBytes_GET_SIZE  PyString_GET_SIZE
-#define PyBytes_FromStringAndSize PyString_FromStringAndSize
-#endif
-
 // Avoid clashes with libstdc++ <locale> by undefining ctype macros
 // that CPython may introduce on macOS when the UTF-8 ctype quirk is enabled.
 // (_PY_PORT_CTYPE_UTF8_ISSUE is defined by CPython’s pyport.h; we apply these