add warnings message

fix some design issues.

Author: Eddy Xu

Include/ceval.h

@@ -30,6 +30,7 @@ PyAPI_FUNC(PyObject *) PyEval_GetGlobals(void);
 PyAPI_FUNC(PyObject *) PyEval_GetLocals(void);
 PyAPI_FUNC(struct _frame *) PyEval_GetFrame(void);
 PyAPI_FUNC(int) PyEval_GetRestricted(void);
+PyAPI_FUNC(int) _Py3kWarn_NextOpcode(void);
 
 /* Look at the current frame's (if any) code's co_flags, and turn on
    the corresponding compiler flags in cf->cf_flags.  Return 1 if any

Include/warnings.h

@@ -26,4 +26,3 @@ PyAPI_FUNC(int) PyErr_WarnExplicit_WithFix(PyObject *, const char *, const char
 }
 #endif
 #endif /* !Py_WARNINGS_H */
-

Lib/test/test_py3kwarn.py

@@ -222,7 +222,7 @@ def test_sort_cmp_arg(self):
             self.assertWarning(sorted(lst, cmp), w, expected)
 
     def test_next_method(self):
-        expected = 'iterator.next() is not supported in 3.x'
+        expected = 'iterator.next() is not supported in 3.x; use __next__() instead'
         it = iter(range(5))
         with check_py3k_warnings() as w:
             self.assertWarning(it.next(), w, expected)

Objects/dictobject.c

@@ -8,7 +8,6 @@
 */
 
 #include "Python.h"
-#include "frameobject.h"
 #include "opcode.h"
 
 
@@ -29,51 +28,9 @@ set_key_error(PyObject *arg)
 /* Define this out if you don't want conversion statistics on exit. */
 #undef SHOW_CONVERSION_COUNTS
 
-static int
-py3kwarn_next_opcode(void)
-{
-    PyFrameObject *frame;
-    char *code;
-    Py_ssize_t n;
-    int offset;
-    int op;
-    int steps;
-
-    frame = PyEval_GetFrame();
-    if (frame == NULL || frame->f_code == NULL)
-        return -1;
-    if (PyString_AsStringAndSize(frame->f_code->co_code, &code, &n) < 0) {
-        PyErr_Clear();
-        return -1;
-    }
-
-    offset = frame->f_lasti;
-    if (offset < 0 || offset >= n)
-        return -1;
-
-    op = (unsigned char)code[offset];
-    offset += 1;
-    if (HAS_ARG(op))
-        offset += 2;
-
-    for (steps = 0; steps < 8 && offset >= 0 && offset < n; steps++) {
-        op = (unsigned char)code[offset];
-        if (op == BINARY_ADD || op == INPLACE_ADD || op == GET_ITER ||
-                op == BINARY_SUBSCR || op == STORE_SUBSCR)
-            return op;
-        if (op == RETURN_VALUE || op == STORE_NAME || op == STORE_FAST ||
-                op == STORE_GLOBAL || op == STORE_ATTR || op == POP_TOP)
-            return -1;
-        offset += 1;
-        if (HAS_ARG(op))
-            offset += 2;
-    }
-    return -1;
-}
-
 #define WARN_DICT_LISTLIKE(MSG) \
     do { \
-        int nextop = py3kwarn_next_opcode(); \
+        int nextop = _Py3kWarn_NextOpcode(); \
         if ((nextop == BINARY_SUBSCR || nextop == STORE_SUBSCR || \
                 nextop == BINARY_ADD || nextop == INPLACE_ADD) && \
                 PyErr_WarnPy3k((MSG), 1) < 0) \

Objects/rangeobject.c

@@ -1,7 +1,6 @@
 /* Range object implementation */
 
 #include "Python.h"
-#include "frameobject.h"
 #include "opcode.h"
 
 typedef struct {
@@ -11,48 +10,6 @@ typedef struct {
     long        len;
 } rangeobject;
 
-static int
-py3kwarn_next_opcode(void)
-{
-    PyFrameObject *frame;
-    char *code;
-    Py_ssize_t n;
-    int offset;
-    int op;
-    int steps;
-
-    frame = PyEval_GetFrame();
-    if (frame == NULL || frame->f_code == NULL)
-        return -1;
-    if (PyString_AsStringAndSize(frame->f_code->co_code, &code, &n) < 0) {
-        PyErr_Clear();
-        return -1;
-    }
-
-    offset = frame->f_lasti;
-    if (offset < 0 || offset >= n)
-        return -1;
-
-    op = (unsigned char)code[offset];
-    offset += 1;
-    if (HAS_ARG(op))
-        offset += 2;
-
-    for (steps = 0; steps < 8 && offset >= 0 && offset < n; steps++) {
-        op = (unsigned char)code[offset];
-        if (op == BINARY_ADD || op == INPLACE_ADD || op == GET_ITER ||
-                op == BINARY_SUBSCR || op == STORE_SUBSCR)
-            return op;
-        if (op == RETURN_VALUE || op == STORE_NAME || op == STORE_FAST ||
-                op == STORE_GLOBAL || op == STORE_ATTR || op == POP_TOP)
-            return -1;
-        offset += 1;
-        if (HAS_ARG(op))
-            offset += 2;
-    }
-    return -1;
-}
-
 /* Return number of items in range (lo, hi, step).  step != 0
  * required.  The result always fits in an unsigned long.
  */
@@ -113,16 +70,14 @@ range_new(PyTypeObject *type, PyObject *args, PyObject *kw)
     unsigned long n;
     int nextop;
 
-    nextop = py3kwarn_next_opcode();
-    if (nextop == GET_ITER) {
-        if (PyErr_WarnPy3k_WithFix("xrange() is not supported in 3.x",
+    nextop = _Py3kWarn_NextOpcode();
+    if (nextop == GET_ITER &&
+            PyErr_WarnPy3k_WithFix("xrange() is not supported in 3.x",
                                    "use range() instead", 1) < 0)
-            return NULL;
-    }
-    else {
-        if (PyErr_WarnPy3k("xrange() may require list materialization in 3.x", 1) < 0)
-            return NULL;
-    }
+        return NULL;
+    if (nextop != GET_ITER &&
+            PyErr_WarnPy3k("xrange() may require list materialization in 3.x", 1) < 0)
+        return NULL;
 
     if (!_PyArg_NoKeywords("xrange()", kw))
         return NULL;

Objects/typeobject.c

@@ -4857,10 +4857,10 @@ wrap_next(PyObject *self, PyObject *args, void *wrapped)
 
     if (!check_num_args(args, 0))
         return NULL;
-    if (Py_TYPE(self)->tp_iter != NULL) {
-        if (PyErr_WarnPy3k("iterator.next() is not supported in 3.x", 1) < 0)
-            return NULL;
-    }
+    if (Py_TYPE(self)->tp_iter != NULL &&
+            PyErr_WarnPy3k("iterator.next() is not supported in 3.x; "
+                           "use __next__() instead", 1) < 0)
+        return NULL;
     res = (*func)(self);
     if (res == NULL && !PyErr_Occurred())
         PyErr_SetNone(PyExc_StopIteration);

Python/bltinmodule.c

@@ -2,7 +2,6 @@
 
 #include "Python.h"
 #include "Python-ast.h"
-#include "frameobject.h"
 
 #include "node.h"
 #include "code.h"
@@ -34,48 +33,6 @@ static PyObject *filterunicode(PyObject *, PyObject *);
 #endif
 static PyObject *filtertuple (PyObject *, PyObject *);
 
-static int
-py3kwarn_next_opcode(void)
-{
-    PyFrameObject *frame;
-    char *code;
-    Py_ssize_t n;
-    int offset;
-    int op;
-    int steps;
-
-    frame = PyEval_GetFrame();
-    if (frame == NULL || frame->f_code == NULL)
-        return -1;
-    if (PyString_AsStringAndSize(frame->f_code->co_code, &code, &n) < 0) {
-        PyErr_Clear();
-        return -1;
-    }
-
-    offset = frame->f_lasti;
-    if (offset < 0 || offset >= n)
-        return -1;
-
-    op = (unsigned char)code[offset];
-    offset += 1;
-    if (HAS_ARG(op))
-        offset += 2;
-
-    for (steps = 0; steps < 8 && offset >= 0 && offset < n; steps++) {
-        op = (unsigned char)code[offset];
-        if (op == BINARY_ADD || op == INPLACE_ADD || op == GET_ITER ||
-                op == BINARY_SUBSCR || op == STORE_SUBSCR)
-            return op;
-        if (op == RETURN_VALUE || op == STORE_NAME || op == STORE_FAST ||
-                op == STORE_GLOBAL || op == STORE_ATTR || op == POP_TOP)
-            return -1;
-        offset += 1;
-        if (HAS_ARG(op))
-            offset += 2;
-    }
-    return -1;
-}
-
 static PyObject *
 builtin___import__(PyObject *self, PyObject *args, PyObject *kwds)
 {
@@ -2021,7 +1978,7 @@ builtin_range(PyObject *self, PyObject *args)
 
     PyObject *v;
 
-    nextop = py3kwarn_next_opcode();
+    nextop = _Py3kWarn_NextOpcode();
     if ((nextop == BINARY_ADD || nextop == INPLACE_ADD) &&
             PyErr_WarnPy3k("range() may require list materialization in 3.x", 1) < 0)
         return NULL;

Python/ceval.c

@@ -19,6 +19,53 @@
 
 #include <ctype.h>
 
+int
+_Py3kWarn_NextOpcode(void)
+{
+    PyFrameObject *frame;
+    char *code;
+    Py_ssize_t n;
+    int offset;
+    int op;
+    int steps;
+
+    frame = PyEval_GetFrame();
+    if (frame == NULL || frame->f_code == NULL)
+        return -1;
+    if (PyString_AsStringAndSize(frame->f_code->co_code, &code, &n) < 0) {
+        PyErr_Clear();
+        return -1;
+    }
+
+    offset = frame->f_lasti;
+    if (offset < 0 || offset >= n)
+        return -1;
+
+    op = (unsigned char)code[offset];
+    offset += 1;
+    if (HAS_ARG(op))
+        offset += 2;
+
+    /* These warnings only care about the immediate consumer of the
+       just-evaluated call result. Looking ahead a handful of opcodes is
+       enough to skip trivial stack setup before we either find a relevant
+       consumer or hit a stop opcode showing the value has already been
+       stored, returned, or discarded. */
+    for (steps = 0; steps < 8 && offset >= 0 && offset < n; steps++) {
+        op = (unsigned char)code[offset];
+        if (op == BINARY_ADD || op == INPLACE_ADD || op == GET_ITER ||
+                op == BINARY_SUBSCR || op == STORE_SUBSCR)
+            return op;
+        if (op == RETURN_VALUE || op == STORE_NAME || op == STORE_FAST ||
+                op == STORE_GLOBAL || op == STORE_ATTR || op == POP_TOP)
+            return -1;
+        offset += 1;
+        if (HAS_ARG(op))
+            offset += 2;
+    }
+    return -1;
+}
+
 #ifndef WITH_TSC
 
 #define READ_TIMESTAMP(var)