Issue #7111: Python can now be run without a stdin, stdout or stderr stream.

It was already the case with Python 2.  However, the corresponding
sys module entries are now set to None (instead of an unusable file object).

1 files changed, 365 insertions, 312 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index f0ea7c90dc..ed82b9411a 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -372,6 +372,7 @@ PyEval_ReleaseThread(PyThreadState *tstate)
 void
 PyEval_ReInitThreads(void)
 {
+    _Py_IDENTIFIER(_after_fork);
     PyObject *threading, *result;
     PyThreadState *tstate = PyThreadState_GET();
 
@@ -392,7 +393,7 @@ PyEval_ReInitThreads(void)
         PyErr_Clear();
         return;
     }
-    result = PyObject_CallMethod(threading, "_after_fork", NULL);
+    result = _PyObject_CallMethodId(threading, &PyId__after_fork, NULL);
     if (result == NULL)
         PyErr_WriteUnraisable(threading);
     else
@@ -491,7 +492,6 @@ static struct {
 } pendingcalls[NPENDINGCALLS];
 static int pendingfirst = 0;
 static int pendinglast = 0;
-static char pendingbusy = 0;
 
 int
 Py_AddPendingCall(int (*func)(void *), void *arg)
@@ -538,6 +538,7 @@ Py_AddPendingCall(int (*func)(void *), void *arg)
 int
 Py_MakePendingCalls(void)
 {
+    static int busy = 0;
     int i;
     int r = 0;
 
@@ -552,9 +553,9 @@ Py_MakePendingCalls(void)
     if (main_thread && PyThread_get_thread_ident() != main_thread)
         return 0;
     /* don't perform recursive pending calls */
-    if (pendingbusy)
+    if (busy)
         return 0;
-    pendingbusy = 1;
+    busy = 1;
     /* perform a bounded number of calls, in case of recursion */
     for (i=0; i<NPENDINGCALLS; i++) {
         int j;
@@ -583,7 +584,7 @@ Py_MakePendingCalls(void)
         if (r)
             break;
     }
-    pendingbusy = 0;
+    busy = 0;
     return r;
 }
 
@@ -749,6 +750,9 @@ enum why_code {
         WHY_SILENCED =  0x0080  /* Exception silenced by 'with' */
 };
 
+static void save_exc_state(PyThreadState *, PyFrameObject *);
+static void swap_exc_state(PyThreadState *, PyFrameObject *);
+static void restore_and_clear_exc_state(PyThreadState *, PyFrameObject *);
 static enum why_code do_raise(PyObject *, PyObject *);
 static int unpack_iterable(PyObject *, int, int, PyObject **);
 
@@ -817,10 +821,6 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
     unsigned char *first_instr;
     PyObject *names;
     PyObject *consts;
-#if defined(Py_DEBUG) || defined(LLTRACE)
-    /* Make it easier to find out where we are with a debugger */
-    char *filename;
-#endif
 
 /* Computed GOTOs, or
        the-optimization-commonly-but-improperly-known-as-"threaded code"
@@ -1114,59 +1114,8 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
         Py_XDECREF(traceback); \
     }
 
-#define SAVE_EXC_STATE() \
-    { \
-        PyObject *type, *value, *traceback; \
-        Py_XINCREF(tstate->exc_type); \
-        Py_XINCREF(tstate->exc_value); \
-        Py_XINCREF(tstate->exc_traceback); \
-        type = f->f_exc_type; \
-        value = f->f_exc_value; \
-        traceback = f->f_exc_traceback; \
-        f->f_exc_type = tstate->exc_type; \
-        f->f_exc_value = tstate->exc_value; \
-        f->f_exc_traceback = tstate->exc_traceback; \
-        Py_XDECREF(type); \
-        Py_XDECREF(value); \
-        Py_XDECREF(traceback); \
-    }
-
-#define SWAP_EXC_STATE() \
-    { \
-        PyObject *tmp; \
-        tmp = tstate->exc_type; \
-        tstate->exc_type = f->f_exc_type; \
-        f->f_exc_type = tmp; \
-        tmp = tstate->exc_value; \
-        tstate->exc_value = f->f_exc_value; \
-        f->f_exc_value = tmp; \
-        tmp = tstate->exc_traceback; \
-        tstate->exc_traceback = f->f_exc_traceback; \
-        f->f_exc_traceback = tmp; \
-    }
-
-#define RESTORE_AND_CLEAR_EXC_STATE() \
-    { \
-        PyObject *type, *value, *tb; \
-        type = tstate->exc_type; \
-        value = tstate->exc_value; \
-        tb = tstate->exc_traceback; \
-        tstate->exc_type = f->f_exc_type; \
-        tstate->exc_value = f->f_exc_value; \
-        tstate->exc_traceback = f->f_exc_traceback; \
-        f->f_exc_type = NULL; \
-        f->f_exc_value = NULL; \
-        f->f_exc_traceback = NULL; \
-        Py_XDECREF(type); \
-        Py_XDECREF(value); \
-        Py_XDECREF(tb); \
-    }
-
 /* Start of code */
 
-    if (f == NULL)
-        return NULL;
-
     /* push frame */
     if (Py_EnterRecursiveCall(""))
         return NULL;
@@ -1240,28 +1189,15 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
             /* We were in an except handler when we left,
                restore the exception state which was put aside
                (see YIELD_VALUE). */
-            SWAP_EXC_STATE();
-        }
-        else {
-            SAVE_EXC_STATE();
+            swap_exc_state(tstate, f);
         }
+        else
+            save_exc_state(tstate, f);
     }
 
 #ifdef LLTRACE
     lltrace = PyDict_GetItemString(f->f_globals, "__lltrace__") != NULL;
 #endif
-#if defined(Py_DEBUG) || defined(LLTRACE)
-    {
-        PyObject *error_type, *error_value, *error_traceback;
-        PyErr_Fetch(&error_type, &error_value, &error_traceback);
-        filename = _PyUnicode_AsString(co->co_filename);
-        if (filename == NULL && tstate->overflowed) {
-            /* maximum recursion depth exceeded */
-            goto exit_eval_frame;
-        }
-        PyErr_Restore(error_type, error_value, error_traceback);
-    }
-#endif
 
     why = WHY_NOT;
     err = 0;
@@ -1412,8 +1348,6 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
            x to NULL, err to nonzero, or why to anything but WHY_NOT,
            and that no operation that succeeds does this! */
 
-        /* case STOP_CODE: this is an error! */
-
         TARGET(NOP)
             FAST_DISPATCH();
 
@@ -2121,7 +2055,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
                 /* Inline the PyDict_GetItem() calls.
                    WARNING: this is an extreme speed hack.
                    Do not try this at home. */
-                Py_hash_t hash = ((PyUnicodeObject *)w)->hash;
+                Py_hash_t hash = ((PyASCIIObject *)w)->hash;
                 if (hash != -1) {
                     PyDictObject *d;
                     PyDictEntry *e;
@@ -2725,7 +2659,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
                 Py_DECREF(*pfunc);
                 *pfunc = self;
                 na++;
-                n++;
+                /* n++; */
             } else
                 Py_INCREF(func);
             sp = stack_pointer;
@@ -2753,9 +2687,11 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
             int kwdefaults = (oparg>>8) & 0xff;
             int num_annotations = (oparg >> 16) & 0x7fff;
 
+            w = POP(); /* qualname */
             v = POP(); /* code object */
-            x = PyFunction_New(v, f->f_globals);
+            x = PyFunction_NewWithQualName(v, f->f_globals, w);
             Py_DECREF(v);
+            Py_DECREF(w);
 
             if (x != NULL && opcode == MAKE_CLOSURE) {
                 v = POP();
@@ -3049,9 +2985,9 @@ fast_yield:
                 break;
         if (i == f->f_iblock)
             /* We did not create this exception. */
-            RESTORE_AND_CLEAR_EXC_STATE()
+            restore_and_clear_exc_state(tstate, f);
         else
-            SWAP_EXC_STATE()
+            swap_exc_state(tstate, f);
     }
 
     if (tstate->use_tracing) {
@@ -3081,7 +3017,7 @@ fast_yield:
                                 PyTrace_RETURN, retval)) {
                 Py_XDECREF(retval);
                 retval = NULL;
-                why = WHY_EXCEPTION;
+                /* why = WHY_EXCEPTION; */
             }
         }
     }
@@ -3094,6 +3030,154 @@ exit_eval_frame:
     return retval;
 }
 
+static void
+format_missing(const char *kind, PyCodeObject *co, PyObject *names)
+{
+    int err;
+    Py_ssize_t len = PyList_GET_SIZE(names);
+    PyObject *name_str, *comma, *tail, *tmp;
+
+    assert(PyList_CheckExact(names));
+    assert(len >= 1);
+    /* Deal with the joys of natural language. */
+    switch (len) {
+    case 1:
+        name_str = PyList_GET_ITEM(names, 0);
+        Py_INCREF(name_str);
+        break;
+    case 2:
+        name_str = PyUnicode_FromFormat("%U and %U",
+                                        PyList_GET_ITEM(names, len - 2),
+                                        PyList_GET_ITEM(names, len - 1));
+        break;
+    default:
+        tail = PyUnicode_FromFormat(", %U, and %U",
+                                    PyList_GET_ITEM(names, len - 2),
+                                    PyList_GET_ITEM(names, len - 1));
+        /* Chop off the last two objects in the list. This shouldn't actually
+           fail, but we can't be too careful. */
+        err = PyList_SetSlice(names, len - 2, len, NULL);
+        if (err == -1) {
+            Py_DECREF(tail);
+            return;
+        }
+        /* Stitch everything up into a nice comma-separated list. */
+        comma = PyUnicode_FromString(", ");
+        if (comma == NULL) {
+            Py_DECREF(tail);
+            return;
+        }
+        tmp = PyUnicode_Join(comma, names);
+        Py_DECREF(comma);
+        if (tmp == NULL) {
+            Py_DECREF(tail);
+            return;
+        }
+        name_str = PyUnicode_Concat(tmp, tail);
+        Py_DECREF(tmp);
+        Py_DECREF(tail);
+        break;
+    }
+    if (name_str == NULL)
+        return;
+    PyErr_Format(PyExc_TypeError,
+                 "%U() missing %i required %s argument%s: %U",
+                 co->co_name,
+                 len,
+                 kind,
+                 len == 1 ? "" : "s",
+                 name_str);
+    Py_DECREF(name_str);
+}
+
+static void
+missing_arguments(PyCodeObject *co, int missing, int defcount,
+                  PyObject **fastlocals)
+{
+    int i, j = 0;
+    int start, end;
+    int positional = defcount != -1;
+    const char *kind = positional ? "positional" : "keyword-only";
+    PyObject *missing_names;
+
+    /* Compute the names of the arguments that are missing. */
+    missing_names = PyList_New(missing);
+    if (missing_names == NULL)
+        return;
+    if (positional) {
+        start = 0;
+        end = co->co_argcount - defcount;
+    }
+    else {
+        start = co->co_argcount;
+        end = start + co->co_kwonlyargcount;
+    }
+    for (i = start; i < end; i++) {
+        if (GETLOCAL(i) == NULL) {
+            PyObject *raw = PyTuple_GET_ITEM(co->co_varnames, i);
+            PyObject *name = PyObject_Repr(raw);
+            if (name == NULL) {
+                Py_DECREF(missing_names);
+                return;
+            }
+            PyList_SET_ITEM(missing_names, j++, name);
+        }
+    }
+    assert(j == missing);
+    format_missing(kind, co, missing_names);
+    Py_DECREF(missing_names);
+}
+
+static void
+too_many_positional(PyCodeObject *co, int given, int defcount, PyObject **fastlocals)
+{
+    int plural;
+    int kwonly_given = 0;
+    int i;
+    PyObject *sig, *kwonly_sig;
+
+    assert((co->co_flags & CO_VARARGS) == 0);
+    /* Count missing keyword-only args. */
+    for (i = co->co_argcount; i < co->co_argcount + co->co_kwonlyargcount; i++)
+        if (GETLOCAL(i) != NULL)
+            kwonly_given++;
+    if (defcount) {
+        int atleast = co->co_argcount - defcount;
+        plural = 1;
+        sig = PyUnicode_FromFormat("from %d to %d", atleast, co->co_argcount);
+    }
+    else {
+        plural = co->co_argcount != 1;
+        sig = PyUnicode_FromFormat("%d", co->co_argcount);
+    }
+    if (sig == NULL)
+        return;
+    if (kwonly_given) {
+        const char *format = " positional argument%s (and %d keyword-only argument%s)";
+        kwonly_sig = PyUnicode_FromFormat(format, given != 1 ? "s" : "", kwonly_given,
+                                              kwonly_given != 1 ? "s" : "");
+        if (kwonly_sig == NULL) {
+            Py_DECREF(sig);
+            return;
+        }
+    }
+    else {
+        /* This will not fail. */
+        kwonly_sig = PyUnicode_FromString("");
+        assert(kwonly_sig != NULL);
+    }
+    PyErr_Format(PyExc_TypeError,
+                 "%U() takes %U positional argument%s but %d%U %s given",
+                 co->co_name,
+                 sig,
+                 plural ? "s" : "",
+                 given,
+                 kwonly_sig,
+                 given == 1 && !kwonly_given ? "was" : "were");
+    Py_DECREF(sig);
+    Py_DECREF(kwonly_sig);
+}
+
 /* This is gonna seem *real weird*, but if you put some other code between
    PyEval_EvalFrame() and PyEval_EvalCodeEx() you will need to adjust
    the test in the if statements in Misc/gdbinit (pystack and pystackv). */
@@ -3110,6 +3194,9 @@ PyEval_EvalCodeEx(PyObject *_co, PyObject *globals, PyObject *locals,
     PyThreadState *tstate = PyThreadState_GET();
     PyObject *x, *u;
     int total_args = co->co_argcount + co->co_kwonlyargcount;
+    int i;
+    int n = argcount;
+    PyObject *kwdict = NULL;
 
     if (globals == NULL) {
         PyErr_SetString(PyExc_SystemError,
@@ -3126,212 +3213,153 @@ PyEval_EvalCodeEx(PyObject *_co, PyObject *globals, PyObject *locals,
     fastlocals = f->f_localsplus;
     freevars = f->f_localsplus + co->co_nlocals;
 
-    if (total_args || co->co_flags & (CO_VARARGS | CO_VARKEYWORDS)) {
-        int i;
-        int n = argcount;
-        PyObject *kwdict = NULL;
-        if (co->co_flags & CO_VARKEYWORDS) {
-            kwdict = PyDict_New();
-            if (kwdict == NULL)
-                goto fail;
-            i = total_args;
-            if (co->co_flags & CO_VARARGS)
-                i++;
-            SETLOCAL(i, kwdict);
-        }
-        if (argcount > co->co_argcount) {
-            if (!(co->co_flags & CO_VARARGS)) {
-                PyErr_Format(PyExc_TypeError,
-                    "%U() takes %s %d "
-                    "positional argument%s (%d given)",
-                    co->co_name,
-                    defcount ? "at most" : "exactly",
-                    co->co_argcount,
-                    co->co_argcount == 1 ? "" : "s",
-                    argcount + kwcount);
-                goto fail;
-            }
-            n = co->co_argcount;
-        }
-        for (i = 0; i < n; i++) {
+    /* Parse arguments. */
+    if (co->co_flags & CO_VARKEYWORDS) {
+        kwdict = PyDict_New();
+        if (kwdict == NULL)
+            goto fail;
+        i = total_args;
+        if (co->co_flags & CO_VARARGS)
+            i++;
+        SETLOCAL(i, kwdict);
+    }
+    if (argcount > co->co_argcount)
+        n = co->co_argcount;
+    for (i = 0; i < n; i++) {
+        x = args[i];
+        Py_INCREF(x);
+        SETLOCAL(i, x);
+    }
+    if (co->co_flags & CO_VARARGS) {
+        u = PyTuple_New(argcount - n);
+        if (u == NULL)
+            goto fail;
+        SETLOCAL(total_args, u);
+        for (i = n; i < argcount; i++) {
             x = args[i];
             Py_INCREF(x);
-            SETLOCAL(i, x);
+            PyTuple_SET_ITEM(u, i-n, x);
         }
-        if (co->co_flags & CO_VARARGS) {
-            u = PyTuple_New(argcount - n);
-            if (u == NULL)
-                goto fail;
-            SETLOCAL(total_args, u);
-            for (i = n; i < argcount; i++) {
-                x = args[i];
-                Py_INCREF(x);
-                PyTuple_SET_ITEM(u, i-n, x);
-            }
+    }
+    for (i = 0; i < kwcount; i++) {
+        PyObject **co_varnames;
+        PyObject *keyword = kws[2*i];
+        PyObject *value = kws[2*i + 1];
+        int j;
+        if (keyword == NULL || !PyUnicode_Check(keyword)) {
+            PyErr_Format(PyExc_TypeError,
+                         "%U() keywords must be strings",
+                         co->co_name);
+            goto fail;
         }
-        for (i = 0; i < kwcount; i++) {
-            PyObject **co_varnames;
-            PyObject *keyword = kws[2*i];
-            PyObject *value = kws[2*i + 1];
-            int j;
-            if (keyword == NULL || !PyUnicode_Check(keyword)) {
-                PyErr_Format(PyExc_TypeError,
-                    "%U() keywords must be strings",
-                    co->co_name);
-                goto fail;
-            }
-            /* Speed hack: do raw pointer compares. As names are
-               normally interned this should almost always hit. */
-            co_varnames = ((PyTupleObject *)(co->co_varnames))->ob_item;
-            for (j = 0; j < total_args; j++) {
-                PyObject *nm = co_varnames[j];
-                if (nm == keyword)
-                    goto kw_found;
-            }
-            /* Slow fallback, just in case */
-            for (j = 0; j < total_args; j++) {
-                PyObject *nm = co_varnames[j];
-                int cmp = PyObject_RichCompareBool(
-                    keyword, nm, Py_EQ);
-                if (cmp > 0)
-                    goto kw_found;
-                else if (cmp < 0)
-                    goto fail;
-            }
-            if (j >= total_args && kwdict == NULL) {
-                PyErr_Format(PyExc_TypeError,
-                             "%U() got an unexpected "
-                             "keyword argument '%S'",
-                             co->co_name,
-                             keyword);
+        /* Speed hack: do raw pointer compares. As names are
+           normally interned this should almost always hit. */
+        co_varnames = ((PyTupleObject *)(co->co_varnames))->ob_item;
+        for (j = 0; j < total_args; j++) {
+            PyObject *nm = co_varnames[j];
+            if (nm == keyword)
+                goto kw_found;
+        }
+        /* Slow fallback, just in case */
+        for (j = 0; j < total_args; j++) {
+            PyObject *nm = co_varnames[j];
+            int cmp = PyObject_RichCompareBool(
+                keyword, nm, Py_EQ);
+            if (cmp > 0)
+                goto kw_found;
+            else if (cmp < 0)
                 goto fail;
-            }
-            PyDict_SetItem(kwdict, keyword, value);
-            continue;
-          kw_found:
-            if (GETLOCAL(j) != NULL) {
-                PyErr_Format(PyExc_TypeError,
+        }
+        if (j >= total_args && kwdict == NULL) {
+            PyErr_Format(PyExc_TypeError,
+                         "%U() got an unexpected "
+                         "keyword argument '%S'",
+                         co->co_name,
+                         keyword);
+            goto fail;
+        }
+        PyDict_SetItem(kwdict, keyword, value);
+        continue;
+      kw_found:
+        if (GETLOCAL(j) != NULL) {
+            PyErr_Format(PyExc_TypeError,
                          "%U() got multiple "
-                         "values for keyword "
-                         "argument '%S'",
+                         "values for argument '%S'",
                          co->co_name,
                          keyword);
-                goto fail;
-            }
-            Py_INCREF(value);
-            SETLOCAL(j, value);
+            goto fail;
         }
-        if (co->co_kwonlyargcount > 0) {
-            for (i = co->co_argcount; i < total_args; i++) {
-                PyObject *name;
-                if (GETLOCAL(i) != NULL)
-                    continue;
-                name = PyTuple_GET_ITEM(co->co_varnames, i);
-                if (kwdefs != NULL) {
-                    PyObject *def = PyDict_GetItem(kwdefs, name);
-                    if (def) {
-                        Py_INCREF(def);
-                        SETLOCAL(i, def);
-                        continue;
-                    }
-                }
-                PyErr_Format(PyExc_TypeError,
-                    "%U() needs keyword-only argument %S",
-                    co->co_name, name);
-                goto fail;
-            }
+        Py_INCREF(value);
+        SETLOCAL(j, value);
+    }
+    if (argcount > co->co_argcount && !(co->co_flags & CO_VARARGS)) {
+        too_many_positional(co, argcount, defcount, fastlocals);
+        goto fail;
+    }
+    if (argcount < co->co_argcount) {
+        int m = co->co_argcount - defcount;
+        int missing = 0;
+        for (i = argcount; i < m; i++)
+            if (GETLOCAL(i) == NULL)
+                missing++;
+        if (missing) {
+            missing_arguments(co, missing, defcount, fastlocals);
+            goto fail;
         }
-        if (argcount < co->co_argcount) {
-            int m = co->co_argcount - defcount;
-            for (i = argcount; i < m; i++) {
-                if (GETLOCAL(i) == NULL) {
-                    int j, given = 0;
-                    for (j = 0; j < co->co_argcount; j++)
-                        if (GETLOCAL(j))
-                            given++;
-                    PyErr_Format(PyExc_TypeError,
-                        "%U() takes %s %d "
-                        "argument%s "
-                        "(%d given)",
-                        co->co_name,
-                        ((co->co_flags & CO_VARARGS) ||
-                         defcount) ? "at least"
-                                   : "exactly",
-                             m, m == 1 ? "" : "s", given);
-                    goto fail;
-                }
+        if (n > m)
+            i = n - m;
+        else
+            i = 0;
+        for (; i < defcount; i++) {
+            if (GETLOCAL(m+i) == NULL) {
+                PyObject *def = defs[i];
+                Py_INCREF(def);
+                SETLOCAL(m+i, def);
             }
-            if (n > m)
-                i = n - m;
-            else
-                i = 0;
-            for (; i < defcount; i++) {
-                if (GETLOCAL(m+i) == NULL) {
-                    PyObject *def = defs[i];
+        }
+    }
+    if (co->co_kwonlyargcount > 0) {
+        int missing = 0;
+        for (i = co->co_argcount; i < total_args; i++) {
+            PyObject *name;
+            if (GETLOCAL(i) != NULL)
+                continue;
+            name = PyTuple_GET_ITEM(co->co_varnames, i);
+            if (kwdefs != NULL) {
+                PyObject *def = PyDict_GetItem(kwdefs, name);
+                if (def) {
                     Py_INCREF(def);
-                    SETLOCAL(m+i, def);
+                    SETLOCAL(i, def);
+                    continue;
                 }
             }
+            missing++;
+        }
+        if (missing) {
+            missing_arguments(co, missing, -1, fastlocals);
+            goto fail;
         }
     }
-    else if (argcount > 0 || kwcount > 0) {
-        PyErr_Format(PyExc_TypeError,
-                     "%U() takes no arguments (%d given)",
-                     co->co_name,
-                     argcount + kwcount);
-        goto fail;
-    }
+
     /* Allocate and initialize storage for cell vars, and copy free
-       vars into frame.  This isn't too efficient right now. */
-    if (PyTuple_GET_SIZE(co->co_cellvars)) {
-        int i, j, nargs, found;
-        Py_UNICODE *cellname, *argname;
+       vars into frame. */
+    for (i = 0; i < PyTuple_GET_SIZE(co->co_cellvars); ++i) {
         PyObject *c;
-
-        nargs = total_args;
-        if (co->co_flags & CO_VARARGS)
-            nargs++;
-        if (co->co_flags & CO_VARKEYWORDS)
-            nargs++;
-
-        /* Initialize each cell var, taking into account
-           cell vars that are initialized from arguments.
-
-           Should arrange for the compiler to put cellvars
-           that are arguments at the beginning of the cellvars
-           list so that we can march over it more efficiently?
-        */
-        for (i = 0; i < PyTuple_GET_SIZE(co->co_cellvars); ++i) {
-            cellname = PyUnicode_AS_UNICODE(
-                PyTuple_GET_ITEM(co->co_cellvars, i));
-            found = 0;
-            for (j = 0; j < nargs; j++) {
-                argname = PyUnicode_AS_UNICODE(
-                    PyTuple_GET_ITEM(co->co_varnames, j));
-                if (Py_UNICODE_strcmp(cellname, argname) == 0) {
-                    c = PyCell_New(GETLOCAL(j));
-                    if (c == NULL)
-                        goto fail;
-                    GETLOCAL(co->co_nlocals + i) = c;
-                    found = 1;
-                    break;
-                }
-            }
-            if (found == 0) {
-                c = PyCell_New(NULL);
-                if (c == NULL)
-                    goto fail;
-                SETLOCAL(co->co_nlocals + i, c);
-            }
-        }
+        int arg;
+        /* Possibly account for the cell variable being an argument. */
+        if (co->co_cell2arg != NULL &&
+            (arg = co->co_cell2arg[i]) != CO_CELL_NOT_AN_ARG)
+            c = PyCell_New(GETLOCAL(arg));
+        else
+            c = PyCell_New(NULL);
+        if (c == NULL)
+            goto fail;
+        SETLOCAL(co->co_nlocals + i, c);
     }
-    if (PyTuple_GET_SIZE(co->co_freevars)) {
-        int i;
-        for (i = 0; i < PyTuple_GET_SIZE(co->co_freevars); ++i) {
-            PyObject *o = PyTuple_GET_ITEM(closure, i);
-            Py_INCREF(o);
-            freevars[PyTuple_GET_SIZE(co->co_cellvars) + i] = o;
-        }
+    for (i = 0; i < PyTuple_GET_SIZE(co->co_freevars); ++i) {
+        PyObject *o = PyTuple_GET_ITEM(closure, i);
+        Py_INCREF(o);
+        freevars[PyTuple_GET_SIZE(co->co_cellvars) + i] = o;
     }
 
     if (co->co_flags & CO_GENERATOR) {
@@ -3377,6 +3405,60 @@ special_lookup(PyObject *o, char *meth, PyObject **cache)
 }
 
 
+/* These 3 functions deal with the exception state of generators. */
+
+static void
+save_exc_state(PyThreadState *tstate, PyFrameObject *f)
+{
+    PyObject *type, *value, *traceback;
+    Py_XINCREF(tstate->exc_type);
+    Py_XINCREF(tstate->exc_value);
+    Py_XINCREF(tstate->exc_traceback);
+    type = f->f_exc_type;
+    value = f->f_exc_value;
+    traceback = f->f_exc_traceback;
+    f->f_exc_type = tstate->exc_type;
+    f->f_exc_value = tstate->exc_value;
+    f->f_exc_traceback = tstate->exc_traceback;
+    Py_XDECREF(type);
+    Py_XDECREF(value);
+    Py_XDECREF(traceback);
+}
+
+static void
+swap_exc_state(PyThreadState *tstate, PyFrameObject *f)
+{
+    PyObject *tmp;
+    tmp = tstate->exc_type;
+    tstate->exc_type = f->f_exc_type;
+    f->f_exc_type = tmp;
+    tmp = tstate->exc_value;
+    tstate->exc_value = f->f_exc_value;
+    f->f_exc_value = tmp;
+    tmp = tstate->exc_traceback;
+    tstate->exc_traceback = f->f_exc_traceback;
+    f->f_exc_traceback = tmp;
+}
+
+static void
+restore_and_clear_exc_state(PyThreadState *tstate, PyFrameObject *f)
+{
+    PyObject *type, *value, *tb;
+    type = tstate->exc_type;
+    value = tstate->exc_value;
+    tb = tstate->exc_traceback;
+    tstate->exc_type = f->f_exc_type;
+    tstate->exc_value = f->f_exc_value;
+    tstate->exc_traceback = f->f_exc_traceback;
+    f->f_exc_type = NULL;
+    f->f_exc_value = NULL;
+    f->f_exc_traceback = NULL;
+    Py_XDECREF(type);
+    Py_XDECREF(value);
+    Py_XDECREF(tb);
+}
+
+
 /* Logic for the raise statement (too complicated for inlining).
    This *consumes* a reference count to each of its arguments. */
 static enum why_code
@@ -4192,7 +4274,7 @@ ext_do_call(PyObject *func, PyObject ***pp_stack, int flags, int na, int nk)
                 if (PyErr_ExceptionMatches(PyExc_TypeError)) {
                     PyErr_Format(PyExc_TypeError,
                                  "%.200s%.200s argument after * "
-                                 "must be a sequence, not %200s",
+                                 "must be a sequence, not %.200s",
                                  PyEval_GetFuncName(func),
                                  PyEval_GetFuncDesc(func),
                                  stararg->ob_type->tp_name);
@@ -4342,7 +4424,9 @@ import_from(PyObject *v, PyObject *name)
 static int
 import_all_from(PyObject *locals, PyObject *v)
 {
-    PyObject *all = PyObject_GetAttrString(v, "__all__");
+    _Py_IDENTIFIER(__all__);
+    _Py_IDENTIFIER(__dict__);
+    PyObject *all = _PyObject_GetAttrId(v, &PyId___all__);
     PyObject *dict, *name, *value;
     int skip_leading_underscores = 0;
     int pos, err;
@@ -4351,7 +4435,7 @@ import_all_from(PyObject *locals, PyObject *v)
         if (!PyErr_ExceptionMatches(PyExc_AttributeError))
             return -1; /* Unexpected error */
         PyErr_Clear();
-        dict = PyObject_GetAttrString(v, "__dict__");
+        dict = _PyObject_GetAttrId(v, &PyId___dict__);
         if (dict == NULL) {
             if (!PyErr_ExceptionMatches(PyExc_AttributeError))
                 return -1;
@@ -4377,7 +4461,8 @@ import_all_from(PyObject *locals, PyObject *v)
         }
         if (skip_leading_underscores &&
             PyUnicode_Check(name) &&
-            PyUnicode_AS_UNICODE(name)[0] == '_')
+            PyUnicode_READY(name) != -1 &&
+            PyUnicode_READ_CHAR(name, 0) == '_')
         {
             Py_DECREF(name);
             continue;
@@ -4437,19 +4522,9 @@ format_exc_unbound(PyCodeObject *co, int oparg)
 
 static PyObject *
 unicode_concatenate(PyObject *v, PyObject *w,
-                   PyFrameObject *f, unsigned char *next_instr)
+                    PyFrameObject *f, unsigned char *next_instr)
 {
-    /* This function implements 'variable += expr' when both arguments
-       are (Unicode) strings. */
-    Py_ssize_t v_len = PyUnicode_GET_SIZE(v);
-    Py_ssize_t w_len = PyUnicode_GET_SIZE(w);
-    Py_ssize_t new_len = v_len + w_len;
-    if (new_len < 0) {
-        PyErr_SetString(PyExc_OverflowError,
-                        "strings are too large to concat");
-        return NULL;
-    }
-
+    PyObject *res;
     if (Py_REFCNT(v) == 2) {
         /* In the common case, there are 2 references to the value
          * stored in 'variable' when the += is performed: one on the
@@ -4490,31 +4565,9 @@ unicode_concatenate(PyObject *v, PyObject *w,
         }
         }
     }
-
-    if (Py_REFCNT(v) == 1 && !PyUnicode_CHECK_INTERNED(v)) {
-        /* Now we own the last reference to 'v', so we can resize it
-         * in-place.
-         */
-        if (PyUnicode_Resize(&v, new_len) != 0) {
-            /* XXX if PyUnicode_Resize() fails, 'v' has been
-             * deallocated so it cannot be put back into
-             * 'variable'.  The MemoryError is raised when there
-             * is no value in 'variable', which might (very
-             * remotely) be a cause of incompatibilities.
-             */
-            return NULL;
-        }
-        /* copy 'w' into the newly allocated area of 'v' */
-        memcpy(PyUnicode_AS_UNICODE(v) + v_len,
-               PyUnicode_AS_UNICODE(w), w_len*sizeof(Py_UNICODE));
-        return v;
-    }
-    else {
-        /* When in-place resizing is not an option. */
-        w = PyUnicode_Concat(v, w);
-        Py_DECREF(v);
-        return w;
-    }
+    res = v;
+    PyUnicode_Append(&res, w);
+    return res;
 }
 
 #ifdef DYNAMIC_EXECUTION_PROFILE