gh-102192: Replace PyErr_Fetch/Restore etc by more efficient alternatives (in Python/)

Python/bytecodes.c

@@ -17,7 +17,7 @@
 #include "pycore_object.h" // _PyObject_GC_TRACK()
 #include "pycore_moduleobject.h" // PyModuleObject
 #include "pycore_opcode.h" // EXTRA_CASES
-#include "pycore_pyerrors.h" // _PyErr_Fetch()
+#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
 #include "pycore_pymem.h" // _PyMem_IsPtrFreed()
 #include "pycore_pystate.h" // _PyInterpreterState_GET()
 #include "pycore_range.h" // _PyRangeIterObject

Python/ceval.c

@@ -13,7 +13,7 @@
 #include "pycore_object.h" // _PyObject_GC_TRACK()
 #include "pycore_moduleobject.h" // PyModuleObject
 #include "pycore_opcode.h" // EXTRA_CASES
-#include "pycore_pyerrors.h" // _PyErr_Fetch()
+#include "pycore_pyerrors.h" // _PyErr_Fetch(), _PyErr_GetRaisedException()
 #include "pycore_pymem.h" // _PyMem_IsPtrFreed()
 #include "pycore_pystate.h" // _PyInterpreterState_GET()
 #include "pycore_range.h" // _PyRangeIterObject
@@ -105,8 +105,7 @@ static void
 dump_stack(_PyInterpreterFrame *frame, PyObject **stack_pointer)
 {
  PyObject **stack_base = _PyFrame_Stackbase(frame);
- PyObject *type, *value, *traceback;
- PyErr_Fetch(&type, &value, &traceback);
+ PyObject *exc = PyErr_GetRaisedException();
  printf(" stack=[");
  for (PyObject **ptr = stack_base; ptr < stack_pointer; ptr++){
  if (ptr != stack_base){
@@ -120,7 +119,7 @@ dump_stack(_PyInterpreterFrame *frame, PyObject **stack_pointer)
  }
  printf("]\n");
  fflush(stdout);
-PyErr_Restore(type, value, traceback);
+PyErr_SetRaisedException(exc);
 }
 
 static void
@@ -157,8 +156,7 @@ lltrace_resume_frame(_PyInterpreterFrame *frame)
  return;
  }
  PyFunctionObject *f = (PyFunctionObject *)fobj;
- PyObject *type, *value, *traceback;
- PyErr_Fetch(&type, &value, &traceback);
+ PyObject *exc = PyErr_GetRaisedException();
  PyObject *name = f->func_qualname;
  if (name == NULL){
  name = f->func_name;
@@ -178,7 +176,7 @@ lltrace_resume_frame(_PyInterpreterFrame *frame)
  }
  printf("\n");
  fflush(stdout);
-PyErr_Restore(type, value, traceback);
+PyErr_SetRaisedException(exc);
 }
 #endif
 static int call_trace(Py_tracefunc, PyObject *,
@@ -1032,7 +1030,6 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
  PyObject *v = POP();
  Py_XDECREF(v);
  }
- PyObject *exc, *val, *tb;
  if (lasti){
  int frame_lasti = _PyInterpreterFrame_LASTI(frame);
  PyObject *lasti = PyLong_FromLong(frame_lasti);
@@ -1041,19 +1038,12 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
  }
  PUSH(lasti);
  }
- _PyErr_Fetch(tstate, &exc, &val, &tb);
+
  /* Make the raw exception data
  available to the handler,
  so a program can emulate the
  Python main loop. */
- _PyErr_NormalizeException(tstate, &exc, &val, &tb);
- if (tb != NULL)
- PyException_SetTraceback(val, tb);
- else
- PyException_SetTraceback(val, Py_None);
- Py_XDECREF(tb);
- Py_XDECREF(exc);
- PUSH(val);
+ PUSH(_PyErr_GetRaisedException(tstate));
  JUMPTO(handler);
  /* Resume normal execution */
  DISPATCH();
@@ -2075,19 +2065,15 @@ call_trace_protected(Py_tracefunc func, PyObject *obj,
  PyThreadState *tstate, _PyInterpreterFrame *frame,
  int what, PyObject *arg)
 {
- PyObject *type, *value, *traceback;
- int err;
- _PyErr_Fetch(tstate, &type, &value, &traceback);
- err = call_trace(func, obj, tstate, frame, what, arg);
+ PyObject *exc = _PyErr_GetRaisedException(tstate);
+ int err = call_trace(func, obj, tstate, frame, what, arg);
  if (err == 0)
 {
-_PyErr_Restore(tstate, type, value, traceback);
+_PyErr_SetRaisedException(tstate, exc);
  return 0;
  }
  else{
- Py_XDECREF(type);
- Py_XDECREF(value);
- Py_XDECREF(traceback);
+ Py_XDECREF(exc);
  return -1;
  }
 }
@@ -2935,18 +2921,15 @@ format_exc_check_arg(PyThreadState *tstate, PyObject *exc,
 
  if (exc == PyExc_NameError){
  // Include the name in the NameError exceptions to offer suggestions later.
- PyObject *type, *value, *traceback;
- PyErr_Fetch(&type, &value, &traceback);
- PyErr_NormalizeException(&type, &value, &traceback);
- if (PyErr_GivenExceptionMatches(value, PyExc_NameError)){
- PyNameErrorObject* exc = (PyNameErrorObject*) value;
- if (exc->name == NULL){
+ PyObject *exc = PyErr_GetRaisedException();
+ if (PyErr_GivenExceptionMatches(exc, PyExc_NameError)){
+ if (((PyNameErrorObject*)exc)->name == NULL){
  // We do not care if this fails because we are going to restore the
  // NameError anyway.
- (void)PyObject_SetAttr(value, &_Py_ID(name), obj);
+ (void)PyObject_SetAttr(exc, &_Py_ID(name), obj);
  }
  }
-PyErr_Restore(type, value, traceback);
+PyErr_SetRaisedException(exc);
  }
 }
 

Python/ceval_gil.c

@@ -2,7 +2,7 @@
 #include "Python.h"
 #include "pycore_atomic.h" // _Py_atomic_int
 #include "pycore_ceval.h" // _PyEval_SignalReceived()
-#include "pycore_pyerrors.h" // _PyErr_Fetch()
+#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
 #include "pycore_pylifecycle.h" // _PyErr_Print()
 #include "pycore_initconfig.h" // _PyStatus_OK()
 #include "pycore_interp.h" // _Py_RunGC()
@@ -870,10 +870,9 @@ _Py_FinishPendingCalls(PyThreadState *tstate)
  }
 
  if (make_pending_calls(tstate->interp) < 0){
- PyObject *exc, *val, *tb;
- _PyErr_Fetch(tstate, &exc, &val, &tb);
+ PyObject *exc = _PyErr_GetRaisedException(tstate);
  PyErr_BadInternalCall();
-_PyErr_ChainExceptions(exc, val, tb);
+_PyErr_ChainExceptions1(exc);
  _PyErr_Print(tstate);
  }
 }

Python/compile.c

@@ -1633,8 +1633,7 @@ static void
 compiler_exit_scope(struct compiler *c)
 {
  // Don't call PySequence_DelItem() with an exception raised
- PyObject *exc_type, *exc_val, *exc_tb;
- PyErr_Fetch(&exc_type, &exc_val, &exc_tb);
+ PyObject *exc = PyErr_GetRaisedException();
 
  c->c_nestlevel--;
  compiler_unit_free(c->u);
@@ -1655,7 +1654,7 @@ compiler_exit_scope(struct compiler *c)
  c->u = NULL;
  }
 
-PyErr_Restore(exc_type, exc_val, exc_tb);
+PyErr_SetRaisedException(exc);
 }
 
 /* Search if variable annotations are present statically in a block. */

Python/frame.c

@@ -29,17 +29,14 @@ PyFrameObject *
 _PyFrame_MakeAndSetFrameObject(_PyInterpreterFrame *frame)
 {
  assert(frame->frame_obj == NULL);
- PyObject *error_type, *error_value, *error_traceback;
- PyErr_Fetch(&error_type, &error_value, &error_traceback);
+ PyObject *exc = PyErr_GetRaisedException();
 
  PyFrameObject *f = _PyFrame_New_NoTrack(frame->f_code);
  if (f == NULL){
- Py_XDECREF(error_type);
- Py_XDECREF(error_value);
- Py_XDECREF(error_traceback);
+ Py_XDECREF(exc);
  return NULL;
  }
-PyErr_Restore(error_type, error_value, error_traceback);
+PyErr_SetRaisedException(exc);
  if (frame->frame_obj){
  // GH-97002: How did we get into this horrible situation? Most likely,
  // allocating f triggered a GC collection, which ran some code that

Python/initconfig.c

@@ -5,7 +5,7 @@
 #include "pycore_interp.h" // _PyInterpreterState.runtime
 #include "pycore_long.h" // _PY_LONG_MAX_STR_DIGITS_THRESHOLD
 #include "pycore_pathconfig.h" // _Py_path_config
-#include "pycore_pyerrors.h" // _PyErr_Fetch()
+#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
 #include "pycore_pylifecycle.h" // _Py_PreInitializeFromConfig()
 #include "pycore_pymem.h" // _PyMem_SetDefaultAllocator()
 #include "pycore_pystate.h" // _PyThreadState_GET()

Python/modsupport.c

@@ -93,16 +93,12 @@ static PyObject *do_mkvalue(const char**, va_list *, int);
 static void
 do_ignore(const char **p_format, va_list *p_va, char endchar, Py_ssize_t n, int flags)
 {
- PyObject *v;
- Py_ssize_t i;
  assert(PyErr_Occurred());
- v = PyTuple_New(n);
- for (i = 0; i < n; i++){
- PyObject *exception, *value, *tb, *w;
-
- PyErr_Fetch(&exception, &value, &tb);
- w = do_mkvalue(p_format, p_va, flags);
- PyErr_Restore(exception, value, tb);
+ PyObject *v = PyTuple_New(n);
+ for (Py_ssize_t i = 0; i < n; i++){
+ PyObject *exc = PyErr_GetRaisedException();
+ PyObject *w = do_mkvalue(p_format, p_va, flags);
+ PyErr_SetRaisedException(exc);
  if (w != NULL){
  if (v != NULL){
  PyTuple_SET_ITEM(v, i, w);

Python/sysmodule.c

@@ -23,7 +23,7 @@ Data members:
 #include "pycore_namespace.h" // _PyNamespace_New()
 #include "pycore_object.h" // _PyObject_IS_GC()
 #include "pycore_pathconfig.h" // _PyPathConfig_ComputeSysPath0()
-#include "pycore_pyerrors.h" // _PyErr_Fetch()
+#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()
 #include "pycore_pylifecycle.h" // _PyErr_WriteUnraisableDefaultHook()
 #include "pycore_pymath.h" // _PY_SHORT_FLOAT_REPR
 #include "pycore_pymem.h" // _PyMem_SetDefaultAllocator()
@@ -89,12 +89,11 @@ PySys_GetObject(const char *name)
 {
  PyThreadState *tstate = _PyThreadState_GET();
 
- PyObject *exc_type, *exc_value, *exc_tb;
- _PyErr_Fetch(tstate, &exc_type, &exc_value, &exc_tb);
+ PyObject *exc = _PyErr_GetRaisedException(tstate);
  PyObject *value = _PySys_GetObject(tstate->interp, name);
  /* XXX Suppress a new exception if it was raised and restore
  * the old one. */
-_PyErr_Restore(tstate, exc_type, exc_value, exc_tb);
+_PyErr_SetRaisedException(tstate, exc);
  return value;
 }
 
@@ -203,8 +202,8 @@ sys_audit_tstate(PyThreadState *ts, const char *event,
 
  int dtrace = PyDTrace_AUDIT_ENABLED();
 
- PyObject *exc_type, *exc_value, *exc_tb;
-_PyErr_Fetch(ts, &exc_type, &exc_value, &exc_tb);
+
+PyObject *exc = _PyErr_GetRaisedException(ts);
 
  /* Initialize event args now */
  if (argFormat && argFormat[0]){
@@ -287,13 +286,11 @@ sys_audit_tstate(PyThreadState *ts, const char *event,
  Py_XDECREF(eventArgs);
 
  if (!res){
-_PyErr_Restore(ts, exc_type, exc_value, exc_tb);
+_PyErr_SetRaisedException(ts, exc);
  }
  else{
  assert(_PyErr_Occurred(ts));
- Py_XDECREF(exc_type);
- Py_XDECREF(exc_value);
- Py_XDECREF(exc_tb);
+ Py_XDECREF(exc);
  }
 
  return res;
@@ -3661,12 +3658,11 @@ static void
 sys_write(PyObject *key, FILE *fp, const char *format, va_list va)
 {
  PyObject *file;
- PyObject *error_type, *error_value, *error_traceback;
  char buffer[1001];
  int written;
  PyThreadState *tstate = _PyThreadState_GET();
 
-_PyErr_Fetch(tstate, &error_type, &error_value, &error_traceback);
+PyObject *exc = _PyErr_GetRaisedException(tstate);
  file = _PySys_GetAttr(tstate, key);
  written = PyOS_vsnprintf(buffer, sizeof(buffer), format, va);
  if (sys_pyfile_write(buffer, file) != 0){
@@ -3678,7 +3674,7 @@ sys_write(PyObject *key, FILE *fp, const char *format, va_list va)
  if (sys_pyfile_write(truncated, file) != 0)
  fputs(truncated, fp);
  }
-_PyErr_Restore(tstate, error_type, error_value, error_traceback);
+_PyErr_SetRaisedException(tstate, exc);
 }
 
 void
@@ -3708,7 +3704,7 @@ sys_format(PyObject *key, FILE *fp, const char *format, va_list va)
  const char *utf8;
  PyThreadState *tstate = _PyThreadState_GET();
 
- PyObject *error = _PyErr_GetRaisedException(tstate);
+ PyObject *exc = _PyErr_GetRaisedException(tstate);
  file = _PySys_GetAttr(tstate, key);
  message = PyUnicode_FromFormatV(format, va);
  if (message != NULL){
@@ -3720,7 +3716,7 @@ sys_format(PyObject *key, FILE *fp, const char *format, va_list va)
  }
  Py_DECREF(message);
  }
- _PyErr_SetRaisedException(tstate, error);
+ _PyErr_SetRaisedException(tstate, exc);
 }
 
 void