Issue #10833: Use PyErr_Format() and PyUnicode_FromFormat() instead of

PyOS_snprintf() to avoid temporary buffer allocated on the stack and a
conversion from bytes to Unicode.

Modules/_datetimemodule.c

@@ -766,7 +766,7 @@ typedef struct
     PyObject *name;
 } PyDateTime_TimeZone;
 
-/* The interned UTC timezone instance */ 
+/* The interned UTC timezone instance */
 static PyObject *PyDateTime_TimeZone_UTC;
 
 /* Create new timezone instance checking offset range.  This
@@ -3287,7 +3287,6 @@ timezone_repr(PyDateTime_TimeZone *self)
 static PyObject *
 timezone_str(PyDateTime_TimeZone *self)
 {
-    char buf[10];
     int hours, minutes, seconds;
     PyObject *offset;
     char sign;
@@ -3313,11 +3312,9 @@ timezone_str(PyDateTime_TimeZone *self)
     Py_DECREF(offset);
     minutes = divmod(seconds, 60, &seconds);
     hours = divmod(minutes, 60, &minutes);
-    assert(seconds == 0);
     /* XXX ignore sub-minute data, curently not allowed. */
-    PyOS_snprintf(buf, sizeof(buf), "UTC%c%02d:%02d", sign, hours, minutes);
-
-    return PyUnicode_FromString(buf);
+    assert(seconds == 0);
+    return PyUnicode_FromFormat("UTC%c%02d:%02d", sign, hours, minutes);
 }
 
 static PyObject *

Modules/_testcapimodule.c

@@ -22,14 +22,7 @@ static PyObject *TestError;     /* set to exception object in init */
 static PyObject *
 raiseTestError(const char* test_name, const char* msg)
 {
-    char buf[2048];
-
-    if (strlen(test_name) + strlen(msg) > sizeof(buf) - 50)
-        PyErr_SetString(TestError, "internal error msg too large");
-    else {
-        PyOS_snprintf(buf, sizeof(buf), "%s: %s", test_name, msg);
-        PyErr_SetString(TestError, buf);
-    }
+    PyErr_Format(TestError, "%s: %s", test_name, msg);
     return NULL;
 }
 

Modules/_tkinter.c

@@ -2400,11 +2400,9 @@ static PyObject *
 Tktt_Repr(PyObject *self)
 {
     TkttObject *v = (TkttObject *)self;
-    char buf[100];
-
-    PyOS_snprintf(buf, sizeof(buf), "<tktimertoken at %p%s>", v,
-                    v->func == NULL ? ", handler deleted" : "");
-    return PyUnicode_FromString(buf);
+    return PyUnicode_FromFormat("<tktimertoken at %p%s>",
+                                v,
+                                v->func == NULL ? ", handler deleted" : "");
 }
 
 static PyTypeObject Tktt_Type =

Modules/readline.c

@@ -233,10 +233,9 @@ set_hook(const char *funcname, PyObject **hook_var, PyObject *args)
         Py_XDECREF(tmp);
     }
     else {
-        PyOS_snprintf(buf, sizeof(buf),
-                      "set_%.50s(func): argument not callable",
-                      funcname);
-        PyErr_SetString(PyExc_TypeError, buf);
+        PyErr_Format(PyExc_TypeError,
+                     "set_%.50s(func): argument not callable",
+                     funcname);
         return NULL;
     }
     Py_RETURN_NONE;
@@ -890,7 +889,7 @@ setup_readline(void)
 #endif
 
 #ifdef __APPLE__
-    /* the libedit readline emulation resets key bindings etc 
+    /* the libedit readline emulation resets key bindings etc
      * when calling rl_initialize.  So call it upfront
      */
     if (using_libedit_emulation)
@@ -930,11 +929,11 @@ setup_readline(void)
      */
 #ifdef __APPLE__
     if (using_libedit_emulation)
-	rl_read_init_file(NULL);
+        rl_read_init_file(NULL);
     else
 #endif /* __APPLE__ */
         rl_initialize();
-    
+
     RESTORE_LOCALE(saved_locale)
 }
 

Objects/complexobject.c

@@ -330,12 +330,10 @@ complex_repr(PyComplexObject *v)
     int precision = 0;
     char format_code = 'r';
     PyObject *result = NULL;
-    Py_ssize_t len;
 
     /* If these are non-NULL, they'll need to be freed. */
     char *pre = NULL;
     char *im = NULL;
-    char *buf = NULL;
 
     /* These do not need to be freed. re is either an alias
        for pre or a pointer to a constant.  lead and tail
@@ -374,20 +372,10 @@ complex_repr(PyComplexObject *v)
         lead = "(";
         tail = ")";
     }
-    /* Alloc the final buffer. Add one for the "j" in the format string,
-       and one for the trailing zero byte. */
-    len = strlen(lead) + strlen(re) + strlen(im) + strlen(tail) + 2;
-    buf = PyMem_Malloc(len);
-    if (!buf) {
-        PyErr_NoMemory();
-        goto done;
-    }
-    PyOS_snprintf(buf, len, "%s%s%sj%s", lead, re, im, tail);
-    result = PyUnicode_FromString(buf);
+    result = PyUnicode_FromFormat("%s%s%sj%s", lead, re, im, tail);
   done:
     PyMem_Free(im);
     PyMem_Free(pre);
-    PyMem_Free(buf);
 
     return result;
 }

Python/getargs.c

@@ -310,20 +310,18 @@ vgetargs1(PyObject *args, const char *format, va_list *p_va, int flags)
         if (max == 0) {
             if (args == NULL)
                 return 1;
-            PyOS_snprintf(msgbuf, sizeof(msgbuf),
-                          "%.200s%s takes no arguments",
-                          fname==NULL ? "function" : fname,
-                          fname==NULL ? "" : "()");
-            PyErr_SetString(PyExc_TypeError, msgbuf);
+            PyErr_Format(PyExc_TypeError,
+                         "%.200s%s takes no arguments",
+                         fname==NULL ? "function" : fname,
+                         fname==NULL ? "" : "()");
             return 0;
         }
         else if (min == 1 && max == 1) {
             if (args == NULL) {
-                PyOS_snprintf(msgbuf, sizeof(msgbuf),
-                      "%.200s%s takes at least one argument",
-                          fname==NULL ? "function" : fname,
-                          fname==NULL ? "" : "()");
-                PyErr_SetString(PyExc_TypeError, msgbuf);
+                PyErr_Format(PyExc_TypeError,
+                             "%.200s%s takes at least one argument",
+                             fname==NULL ? "function" : fname,
+                             fname==NULL ? "" : "()");
                 return 0;
             }
             msg = convertitem(args, &format, p_va, flags, levels,
@@ -349,20 +347,18 @@ vgetargs1(PyObject *args, const char *format, va_list *p_va, int flags)
     len = PyTuple_GET_SIZE(args);
 
     if (len < min || max < len) {
-        if (message == NULL) {
-            PyOS_snprintf(msgbuf, sizeof(msgbuf),
-                          "%.150s%s takes %s %d argument%s "
-                          "(%ld given)",
-                          fname==NULL ? "function" : fname,
-                          fname==NULL ? "" : "()",
-                          min==max ? "exactly"
-                          : len < min ? "at least" : "at most",
-                          len < min ? min : max,
-                          (len < min ? min : max) == 1 ? "" : "s",
-                          Py_SAFE_DOWNCAST(len, Py_ssize_t, long));
-            message = msgbuf;
-        }
-        PyErr_SetString(PyExc_TypeError, message);
+        if (message == NULL)
+            PyErr_Format(PyExc_TypeError,
+                         "%.150s%s takes %s %d argument%s (%ld given)",
+                         fname==NULL ? "function" : fname,
+                         fname==NULL ? "" : "()",
+                         min==max ? "exactly"
+                         : len < min ? "at least" : "at most",
+                         len < min ? min : max,
+                         (len < min ? min : max) == 1 ? "" : "s",
+                         Py_SAFE_DOWNCAST(len, Py_ssize_t, long));
+        else
+            PyErr_SetString(PyExc_TypeError, message);
         return 0;
     }
 
@@ -1458,8 +1454,8 @@ vgetargskeywords(PyObject *args, PyObject *keywords, const char *format,
     nargs = PyTuple_GET_SIZE(args);
     nkeywords = (keywords == NULL) ? 0 : PyDict_Size(keywords);
     if (nargs + nkeywords > len) {
-        PyErr_Format(PyExc_TypeError, "%s%s takes at most %d "
-                     "argument%s (%d given)",
+        PyErr_Format(PyExc_TypeError,
+                     "%s%s takes at most %d argument%s (%d given)",
                      (fname == NULL) ? "function" : fname,
                      (fname == NULL) ? "" : "()",
                      len,