gh-109611: Add convenient C API function _PyFile_Flush() (GH-109612)

4 files changed, 13 insertions, 42 deletions

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 8e234e0..69056bf 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2083,11 +2083,9 @@ builtin_print_impl(PyObject *module, PyObject *args, PyObject *sep,
     }
 
     if (flush) {
-        PyObject *tmp = PyObject_CallMethodNoArgs(file, &_Py_ID(flush));
-        if (tmp == NULL) {
+        if (_PyFile_Flush(file) < 0) {
             return NULL;
         }
-        Py_DECREF(tmp);
     }
 
     Py_RETURN_NONE;
@@ -2146,11 +2144,9 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
     }
 
     /* First of all, flush stderr */
-    tmp = PyObject_CallMethodNoArgs(ferr, &_Py_ID(flush));
-    if (tmp == NULL)
+    if (_PyFile_Flush(ferr) < 0) {
         PyErr_Clear();
-    else
-        Py_DECREF(tmp);
+    }
 
     /* We should only use (GNU) readline if Python's sys.stdin and
        sys.stdout are the same as C's stdin and stdout, because we
@@ -2218,11 +2214,9 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
         if (stdin_errors_str == NULL) {
             goto _readline_errors;
         }
-        tmp = PyObject_CallMethodNoArgs(fout, &_Py_ID(flush));
-        if (tmp == NULL)
+        if (_PyFile_Flush(fout) < 0) {
             PyErr_Clear();
-        else
-            Py_DECREF(tmp);
+        }
         if (prompt != NULL) {
             /* We have a prompt, encode it as stdout would */
             const char *stdout_encoding_str, *stdout_errors_str;
@@ -2325,11 +2319,9 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
         if (PyFile_WriteObject(prompt, fout, Py_PRINT_RAW) != 0)
             return NULL;
     }
-    tmp = PyObject_CallMethodNoArgs(fout, &_Py_ID(flush));
-    if (tmp == NULL)
+    if (_PyFile_Flush(fout) < 0) {
         PyErr_Clear();
-    else
-        Py_DECREF(tmp);
+    }
     return PyFile_GetLine(fin, -1);
 }
 
diff --git a/Python/errors.c b/Python/errors.c
index e6fa15f..b05b3ef 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -1513,11 +1513,9 @@ write_unraisable_exc_file(PyThreadState *tstate, PyObject *exc_type,
     }
 
     /* Explicitly call file.flush() */
-    PyObject *res = PyObject_CallMethodNoArgs(file, &_Py_ID(flush));
-    if (!res) {
+    if (_PyFile_Flush(file) < 0) {
         return -1;
     }
-    Py_DECREF(res);
 
     return 0;
 }
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 4800015..aec8da1 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1639,27 +1639,20 @@ flush_std_files(void)
     PyThreadState *tstate = _PyThreadState_GET();
     PyObject *fout = _PySys_GetAttr(tstate, &_Py_ID(stdout));
     PyObject *ferr = _PySys_GetAttr(tstate, &_Py_ID(stderr));
-    PyObject *tmp;
     int status = 0;
 
     if (fout != NULL && fout != Py_None && !file_is_closed(fout)) {
-        tmp = PyObject_CallMethodNoArgs(fout, &_Py_ID(flush));
-        if (tmp == NULL) {
+        if (_PyFile_Flush(fout) < 0) {
             PyErr_WriteUnraisable(fout);
             status = -1;
         }
-        else
-            Py_DECREF(tmp);
     }
 
     if (ferr != NULL && ferr != Py_None && !file_is_closed(ferr)) {
-        tmp = PyObject_CallMethodNoArgs(ferr, &_Py_ID(flush));
-        if (tmp == NULL) {
+        if (_PyFile_Flush(ferr) < 0) {
             PyErr_Clear();
             status = -1;
         }
-        else
-            Py_DECREF(tmp);
     }
 
     return status;
@@ -2632,13 +2625,9 @@ _Py_FatalError_PrintExc(PyThreadState *tstate)
     Py_DECREF(exc);
 
     /* sys.stderr may be buffered: call sys.stderr.flush() */
-    PyObject *res = PyObject_CallMethodNoArgs(ferr, &_Py_ID(flush));
-    if (res == NULL) {
+    if (_PyFile_Flush(ferr) < 0) {
         _PyErr_Clear(tstate);
     }
-    else {
-        Py_DECREF(res);
-    }
 
     return has_tb;
 }
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index e3d03a8..81ab78e 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1562,14 +1562,10 @@ _PyErr_Display(PyObject *file, PyObject *unused, PyObject *value, PyObject *tb)
     Py_XDECREF(ctx.seen);
 
     /* Call file.flush() */
-    PyObject *res = PyObject_CallMethodNoArgs(file, &_Py_ID(flush));
-    if (!res) {
+    if (_PyFile_Flush(file) < 0) {
         /* Silently ignore file.flush() error */
         PyErr_Clear();
     }
-    else {
-        Py_DECREF(res);
-    }
 }
 
 void
@@ -1674,11 +1670,7 @@ flush_io_stream(PyThreadState *tstate, PyObject *name)
 {
     PyObject *f = _PySys_GetAttr(tstate, name);
     if (f != NULL) {
-        PyObject *r = PyObject_CallMethodNoArgs(f, &_Py_ID(flush));
-        if (r) {
-            Py_DECREF(r);
-        }
-        else {
+        if (_PyFile_Flush(f) < 0) {
             PyErr_Clear();
         }
     }