Add BRANCH_LEFT and BRANCH_RIGHT events to sys.monitoring for coverage tools

Author: markshannon

Include/cpython/code.h

@@ -11,11 +11,11 @@ extern "C" {
 /* Total tool ids available */
 #define  _PY_MONITORING_TOOL_IDS 8
 /* Count of all local monitoring events */
-#define  _PY_MONITORING_LOCAL_EVENTS 10
+#define  _PY_MONITORING_LOCAL_EVENTS 11
 /* Count of all "real" monitoring events (not derived from other events) */
-#define _PY_MONITORING_UNGROUPED_EVENTS 15
+#define _PY_MONITORING_UNGROUPED_EVENTS 16
 /* Count of all  monitoring events */
-#define _PY_MONITORING_EVENTS 17
+#define _PY_MONITORING_EVENTS 19
 
 /* Tables of which tools are active for each monitored event. */
 typedef struct _Py_LocalMonitors {

Include/cpython/monitoring.h

@@ -13,25 +13,27 @@
 #define PY_MONITORING_EVENT_LINE 5
 #define PY_MONITORING_EVENT_INSTRUCTION 6
 #define PY_MONITORING_EVENT_JUMP 7
-#define PY_MONITORING_EVENT_BRANCH 8
-#define PY_MONITORING_EVENT_STOP_ITERATION 9
+#define PY_MONITORING_EVENT_BRANCH_LEFT 8
+#define PY_MONITORING_EVENT_BRANCH_RIGHT 9
+#define PY_MONITORING_EVENT_STOP_ITERATION 10
 
 #define PY_MONITORING_IS_INSTRUMENTED_EVENT(ev) \
     ((ev) < _PY_MONITORING_LOCAL_EVENTS)
 
 /* Other events, mainly exceptions */
 
-#define PY_MONITORING_EVENT_RAISE 10
-#define PY_MONITORING_EVENT_EXCEPTION_HANDLED 11
-#define PY_MONITORING_EVENT_PY_UNWIND 12
-#define PY_MONITORING_EVENT_PY_THROW 13
-#define PY_MONITORING_EVENT_RERAISE 14
+#define PY_MONITORING_EVENT_RAISE 11
+#define PY_MONITORING_EVENT_EXCEPTION_HANDLED 12
+#define PY_MONITORING_EVENT_PY_UNWIND 13
+#define PY_MONITORING_EVENT_PY_THROW 14
+#define PY_MONITORING_EVENT_RERAISE 15
 
 
 /* Ancillary events */
 
-#define PY_MONITORING_EVENT_C_RETURN 15
-#define PY_MONITORING_EVENT_C_RAISE 16
+#define PY_MONITORING_EVENT_C_RETURN 16
+#define PY_MONITORING_EVENT_C_RAISE 17
+#define PY_MONITORING_EVENT_BRANCH 18
 
 
 typedef struct _PyMonitoringState {
@@ -74,10 +76,18 @@ PyAPI_FUNC(int)
 _PyMonitoring_FireJumpEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
                             PyObject *target_offset);
 
-PyAPI_FUNC(int)
+Py_DEPRECATED(3.14) PyAPI_FUNC(int)
 _PyMonitoring_FireBranchEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
                               PyObject *target_offset);
 
+PyAPI_FUNC(int)
+_PyMonitoring_FireBranchRightEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
+                              PyObject *target_offset);
+
+PyAPI_FUNC(int)
+_PyMonitoring_FireBranchLeftEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
+                              PyObject *target_offset);
+
 PyAPI_FUNC(int)
 _PyMonitoring_FireCReturnEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
                                PyObject *retval);
@@ -174,12 +184,21 @@ PyMonitoring_FireJumpEvent(PyMonitoringState *state, PyObject *codelike, int32_t
 }
 
 static inline int
-PyMonitoring_FireBranchEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
+PyMonitoring_FireBranchRightEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
+                             PyObject *target_offset)
+{
+    _PYMONITORING_IF_ACTIVE(
+        state,
+        _PyMonitoring_FireBranchRightEvent(state, codelike, offset, target_offset));
+}
+
+static inline int
+PyMonitoring_FireBranchLeftEvent(PyMonitoringState *state, PyObject *codelike, int32_t offset,
                              PyObject *target_offset)
 {
     _PYMONITORING_IF_ACTIVE(
         state,
-        _PyMonitoring_FireBranchEvent(state, codelike, offset, target_offset));
+        _PyMonitoring_FireBranchLeftEvent(state, codelike, offset, target_offset));
 }
 
 static inline int

Include/internal/pycore_code.h

@@ -603,6 +603,8 @@ extern _Py_CODEUNIT _Py_GetBaseCodeUnit(PyCodeObject *code, int offset);
 
 extern int _PyInstruction_GetLength(PyCodeObject *code, int offset);
 
+extern PyObject *_PyInstrumentation_BranchesIterator(PyCodeObject *code);
+
 struct _PyCode8 _PyCode_DEF(8);
 
 PyAPI_DATA(const struct _PyCode8) _Py_InitCleanup;

Include/internal/pycore_magic_number.h

@@ -262,6 +262,7 @@ Known values:
     Python 3.14a1 3607 (Add pseudo instructions JUMP_IF_TRUE/FALSE)
     Python 3.14a1 3608 (Add support for slices)
     Python 3.14a2 3609 (Add LOAD_SMALL_INT and LOAD_CONST_IMMORTAL instructions, remove RETURN_CONST)
+    Python 3.14a3 3610 (Add NOT_TAKEN instruction)
 
     Python 3.15 will start with 3650
 
@@ -274,7 +275,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3609
+#define PYC_MAGIC_NUMBER 3610
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \