Add a new utility function "__Pyx_PyObject_GetAttrStrNoError()" that does not raise AttributeError if the lookup fails, and use "_PyObject_GenericGetAttrWithDict()" for it in Py3.7+ to avoid instantiating the exception completely.

5 files changed, 74 insertions, 43 deletions

diff --git a/Cython/Utility/Builtins.c b/Cython/Utility/Builtins.c
index df5c41fbc..c508917d5 100644
--- a/Cython/Utility/Builtins.c
+++ b/Cython/Utility/Builtins.c
@@ -167,7 +167,7 @@ bad:
 static CYTHON_INLINE PyObject *__Pyx_GetAttr3(PyObject *, PyObject *, PyObject *); /*proto*/
 
 //////////////////// GetAttr3 ////////////////////
-//@requires: ObjectHandling.c::GetAttr
+//@requires: ObjectHandling.c::PyObjectGetAttrStr
 //@requires: Exceptions.c::PyThreadStateGet
 //@requires: Exceptions.c::PyErrFetchRestore
 //@requires: Exceptions.c::PyErrExceptionMatches
@@ -183,7 +183,17 @@ static PyObject *__Pyx_GetAttr3Default(PyObject *d) {
 }
 
 static CYTHON_INLINE PyObject *__Pyx_GetAttr3(PyObject *o, PyObject *n, PyObject *d) {
-    PyObject *r = __Pyx_GetAttr(o, n);
+    PyObject *r;
+#if CYTHON_USE_TYPE_SLOTS
+    if (likely(PyString_Check(n))) {
+        r = __Pyx_PyObject_GetAttrStrNoError(o, n);
+        if (unlikely(!r) && likely(!PyErr_Occurred())) {
+            r = __Pyx_NewRef(d);
+        }
+        return r;
+    }
+#endif
+    r = PyObject_GetAttr(o, n);
     return (likely(r)) ? r : __Pyx_GetAttr3Default(d);
 }
 
diff --git a/Cython/Utility/Coroutine.c b/Cython/Utility/Coroutine.c
index 8cd3138b2..54e370766 100644
--- a/Cython/Utility/Coroutine.c
+++ b/Cython/Utility/Coroutine.c
@@ -485,6 +485,7 @@ static int __pyx_Generator_init(void); /*proto*/
 //@requires: Exceptions.c::SaveResetException
 //@requires: ObjectHandling.c::PyObjectCallMethod1
 //@requires: ObjectHandling.c::PyObjectGetAttrStr
+//@requires: ObjectHandling.c::PyObjectGetAttrStrNoError
 //@requires: CommonStructures.c::FetchCommonType
 
 #include <structmember.h>
@@ -894,12 +895,11 @@ static int __Pyx_Coroutine_CloseIter(__pyx_CoroutineObject *gen, PyObject *yf) {
     {
         PyObject *meth;
         gen->is_running = 1;
-        meth = __Pyx_PyObject_GetAttrStr(yf, PYIDENT("close"));
+        meth = __Pyx_PyObject_GetAttrStrNoError(yf, PYIDENT("close"));
         if (unlikely(!meth)) {
-            if (!PyErr_ExceptionMatches(PyExc_AttributeError)) {
+            if (unlikely(PyErr_Occurred())) {
                 PyErr_WriteUnraisable(yf);
             }
-            PyErr_Clear();
         } else {
             retval = PyObject_CallFunction(meth, NULL);
             Py_DECREF(meth);
@@ -1041,14 +1041,13 @@ static PyObject *__Pyx__Coroutine_Throw(PyObject *self, PyObject *typ, PyObject
             ret = __Pyx__Coroutine_Throw(((__pyx_CoroutineAwaitObject*)yf)->coroutine, typ, val, tb, args, close_on_genexit);
         #endif
         } else {
-            PyObject *meth = __Pyx_PyObject_GetAttrStr(yf, PYIDENT("throw"));
+            PyObject *meth = __Pyx_PyObject_GetAttrStrNoError(yf, PYIDENT("throw"));
             if (unlikely(!meth)) {
                 Py_DECREF(yf);
-                if (!PyErr_ExceptionMatches(PyExc_AttributeError)) {
+                if (unlikely(PyErr_Occurred())) {
                     gen->is_running = 0;
                     return NULL;
                 }
-                PyErr_Clear();
                 __Pyx_Coroutine_Undelegate(gen);
                 gen->is_running = 0;
                 goto throw_here;
diff --git a/Cython/Utility/Exceptions.c b/Cython/Utility/Exceptions.c
index 29a2ae4c7..3dd563628 100644
--- a/Cython/Utility/Exceptions.c
+++ b/Cython/Utility/Exceptions.c
@@ -641,7 +641,7 @@ static int __Pyx_CLineForTraceback(PyThreadState *tstate, int c_line);/*proto*/
 #endif
 
 /////////////// CLineInTraceback ///////////////
-//@requires: ObjectHandling.c::PyObjectGetAttrStr
+//@requires: ObjectHandling.c::PyObjectGetAttrStrNoError
 //@requires: PyErrFetchRestore
 //@substitute: naming
 
@@ -669,7 +669,7 @@ static int __Pyx_CLineForTraceback(PyThreadState *tstate, int c_line) {
     } else
 #endif
     {
-      PyObject *use_cline_obj = __Pyx_PyObject_GetAttrStr(${cython_runtime_cname}, PYIDENT("cline_in_traceback"));
+      PyObject *use_cline_obj = __Pyx_PyObject_GetAttrStrNoError(${cython_runtime_cname}, PYIDENT("cline_in_traceback"));
       if (use_cline_obj) {
         use_cline = PyObject_Not(use_cline_obj) ? Py_False : Py_True;
         Py_DECREF(use_cline_obj);
diff --git a/Cython/Utility/ExtensionTypes.c b/Cython/Utility/ExtensionTypes.c
index fc11fafa7..50d0e2137 100644
--- a/Cython/Utility/ExtensionTypes.c
+++ b/Cython/Utility/ExtensionTypes.c
@@ -132,6 +132,7 @@ static void __Pyx_call_next_tp_clear(PyObject* obj, inquiry current_tp_clear) {
 static int __Pyx_setup_reduce(PyObject* type_obj);
 
 /////////////// SetupReduce ///////////////
+//@requires: ObjectHandling.c::PyObjectGetAttrStrNoError
 //@requires: ObjectHandling.c::PyObjectGetAttrStr
 //@substitute: naming
 
@@ -139,7 +140,7 @@ static int __Pyx_setup_reduce_is_named(PyObject* meth, PyObject* name) {
   int ret;
   PyObject *name_attr;
 
-  name_attr = __Pyx_PyObject_GetAttrStr(meth, PYIDENT("__name__"));
+  name_attr = __Pyx_PyObject_GetAttrStrNoError(meth, PYIDENT("__name__"));
   if (likely(name_attr)) {
       ret = PyObject_RichCompareBool(name_attr, name, Py_EQ);
   } else {
@@ -192,7 +193,7 @@ static int __Pyx_setup_reduce(PyObject* type_obj) {
             ret = PyDict_SetItem(((PyTypeObject*)type_obj)->tp_dict, PYIDENT("__reduce__"), reduce_cython); if (unlikely(ret < 0)) goto BAD;
             ret = PyDict_DelItem(((PyTypeObject*)type_obj)->tp_dict, PYIDENT("__reduce_cython__")); if (unlikely(ret < 0)) goto BAD;
 
-            setstate = __Pyx_PyObject_GetAttrStr(type_obj, PYIDENT("__setstate__"));
+            setstate = __Pyx_PyObject_GetAttrStrNoError(type_obj, PYIDENT("__setstate__"));
             if (!setstate) PyErr_Clear();
             if (!setstate || __Pyx_setup_reduce_is_named(setstate, PYIDENT("__setstate_cython__"))) {
                 setstate_cython = __Pyx_PyObject_GetAttrStr(type_obj, PYIDENT("__setstate_cython__")); if (unlikely(!setstate_cython)) goto BAD;
diff --git a/Cython/Utility/ObjectHandling.c b/Cython/Utility/ObjectHandling.c
index 5c687759c..a90911142 100644
--- a/Cython/Utility/ObjectHandling.c
+++ b/Cython/Utility/ObjectHandling.c
@@ -943,14 +943,14 @@ static PyObject *__Pyx_Py3ClassCreate(PyObject *metaclass, PyObject *name, PyObj
                                       PyObject *mkw, int calculate_metaclass, int allow_py2_metaclass); /*proto*/
 
 /////////////// Py3ClassCreate ///////////////
-//@requires: PyObjectGetAttrStr
+//@requires: PyObjectGetAttrStrNoError
 //@requires: CalculateMetaclass
 
 static PyObject *__Pyx_Py3MetaclassPrepare(PyObject *metaclass, PyObject *bases, PyObject *name,
                                            PyObject *qualname, PyObject *mkw, PyObject *modname, PyObject *doc) {
     PyObject *ns;
     if (metaclass) {
-        PyObject *prep = __Pyx_PyObject_GetAttrStr(metaclass, PYIDENT("__prepare__"));
+        PyObject *prep = __Pyx_PyObject_GetAttrStrNoError(metaclass, PYIDENT("__prepare__"));
         if (prep) {
             PyObject *pargs = PyTuple_Pack(2, name, bases);
             if (unlikely(!pargs)) {
@@ -961,9 +961,8 @@ static PyObject *__Pyx_Py3MetaclassPrepare(PyObject *metaclass, PyObject *bases,
             Py_DECREF(prep);
             Py_DECREF(pargs);
         } else {
-            if (unlikely(!PyErr_ExceptionMatches(PyExc_AttributeError)))
+            if (unlikely(PyErr_Occurred()))
                 return NULL;
-            PyErr_Clear();
             ns = PyDict_New();
         }
     } else {
@@ -1099,12 +1098,12 @@ static CYTHON_INLINE PyObject* __Pyx_PyBoolOrNull_FromLong(long b) {
 static PyObject *__Pyx_GetBuiltinName(PyObject *name); /*proto*/
 
 /////////////// GetBuiltinName ///////////////
-//@requires: PyObjectGetAttrStr
+//@requires: PyObjectGetAttrStrNoError
 //@substitute: naming
 
 static PyObject *__Pyx_GetBuiltinName(PyObject *name) {
-    PyObject* result = __Pyx_PyObject_GetAttrStr($builtins_cname, name);
-    if (unlikely(!result)) {
+    PyObject* result = __Pyx_PyObject_GetAttrStrNoError($builtins_cname, name);
+    if (unlikely(!result) && !PyErr_Occurred()) {
         PyErr_Format(PyExc_NameError,
 #if PY_MAJOR_VERSION >= 3
             "name '%U' is not defined", name);
@@ -1121,28 +1120,17 @@ static PyObject *__Pyx_GetBuiltinName(PyObject *name) {
 static PyObject *__Pyx__GetNameInClass(PyObject *nmspace, PyObject *name); /*proto*/
 
 /////////////// GetNameInClass ///////////////
-//@requires: PyObjectGetAttrStr
+//@requires: PyObjectGetAttrStrNoError
 //@requires: GetModuleGlobalName
-//@requires: Exceptions.c::PyThreadStateGet
-//@requires: Exceptions.c::PyErrFetchRestore
-//@requires: Exceptions.c::PyErrExceptionMatches
-
-static PyObject *__Pyx_GetGlobalNameAfterAttributeLookup(PyObject *name) {
-    PyObject *result;
-    __Pyx_PyThreadState_declare
-    __Pyx_PyThreadState_assign
-    if (unlikely(!__Pyx_PyErr_ExceptionMatches(PyExc_AttributeError)))
-        return NULL;
-    __Pyx_PyErr_Clear();
-    __Pyx_GetModuleGlobalNameUncached(result, name);
-    return result;
-}
 
 static PyObject *__Pyx__GetNameInClass(PyObject *nmspace, PyObject *name) {
     PyObject *result;
-    result = __Pyx_PyObject_GetAttrStr(nmspace, name);
+    result = __Pyx_PyObject_GetAttrStrNoError(nmspace, name);
     if (!result) {
-        result = __Pyx_GetGlobalNameAfterAttributeLookup(name);
+        if (unlikely(PyErr_Occurred()))
+            return NULL;
+        __Pyx_GetModuleGlobalNameUncached(result, name);
+        return result;
     }
     return result;
 }
@@ -1358,6 +1346,41 @@ static PyObject* __Pyx_PyObject_GenericGetAttr(PyObject* obj, PyObject* attr_nam
 #endif
 
 
+/////////////// PyObjectGetAttrStrNoError.proto ///////////////
+
+static CYTHON_INLINE PyObject* __Pyx_PyObject_GetAttrStrNoError(PyObject* obj, PyObject* attr_name);/*proto*/
+
+/////////////// PyObjectGetAttrStrNoError ///////////////
+//@requires: PyObjectGetAttrStr
+//@requires: Exceptions.c::PyThreadStateGet
+//@requires: Exceptions.c::PyErrFetchRestore
+//@requires: Exceptions.c::PyErrExceptionMatches
+
+static void __Pyx_PyObject_GetAttrStr_ClearAttributeError(void) {
+    __Pyx_PyThreadState_declare
+    __Pyx_PyThreadState_assign
+    if (likely(__Pyx_PyErr_ExceptionMatches(PyExc_AttributeError)))
+        __Pyx_PyErr_Clear();
+}
+
+static CYTHON_INLINE PyObject* __Pyx_PyObject_GetAttrStrNoError(PyObject* obj, PyObject* attr_name) {
+    PyObject *result;
+#if CYTHON_COMPILING_IN_CPYTHON && CYTHON_USE_TYPE_SLOTS && PY_VERSION_HEX >= 0x030700B1
+    // _PyObject_GenericGetAttrWithDict() in CPython 3.7+ can avoid raising the AttributeError.
+    // See https://bugs.python.org/issue32544
+    PyTypeObject* tp = Py_TYPE(obj);
+    if (likely(tp->tp_getattro == PyObject_GenericGetAttr)) {
+        return _PyObject_GenericGetAttrWithDict(obj, attr_name, NULL, 1);
+    }
+#endif
+    result = __Pyx_PyObject_GetAttrStr(obj, attr_name);
+    if (unlikely(!result)) {
+        __Pyx_PyObject_GetAttrStr_ClearAttributeError();
+    }
+    return result;
+}
+
+
 /////////////// PyObjectGetAttrStr.proto ///////////////
 
 #if CYTHON_USE_TYPE_SLOTS
@@ -2303,7 +2326,7 @@ static PyObject* __Pyx_PyNumber_InPlaceMatrixMultiply(PyObject* x, PyObject* y);
 #endif
 
 /////////////// MatrixMultiply ///////////////
-//@requires: PyObjectGetAttrStr
+//@requires: PyObjectGetAttrStrNoError
 //@requires: PyObjectCallOneArg
 //@requires: PyFunctionFastCall
 //@requires: PyCFunctionFastCall
@@ -2353,17 +2376,15 @@ done:
     return result;
 }
 
-#define __Pyx_TryMatrixMethod(x, y, py_method_name) {                   \
-    PyObject *func = __Pyx_PyObject_GetAttrStr(x, py_method_name);      \
+#define __Pyx_TryMatrixMethod(x, y, py_method_name) {                     \
+    PyObject *func = __Pyx_PyObject_GetAttrStrNoError(x, py_method_name); \
     if (func) {                                                         \
         PyObject *result = __Pyx_PyObject_CallMatrixMethod(func, y);    \
         if (result != Py_NotImplemented)                                \
             return result;                                              \
         Py_DECREF(result);                                              \
-    } else {                                                            \
-        if (!PyErr_ExceptionMatches(PyExc_AttributeError))              \
-            return NULL;                                                \
-        PyErr_Clear();                                                  \
+    } else if (unlikely(PyErr_Occurred())) {                            \
+        return NULL;                                                    \
     }                                                                   \
 }