bpo-38644: Add _PySys_Audit() which takes tstate (GH-19180)

Add _PySys_Audit() function to the internal C API: similar to
PySys_Audit(), but requires a mandatory tstate parameter.

Cleanup sys_audit_tstate() code: remove code path for NULL tstate,
since the function exits at entry if tstate is NULL. Remove also code
path for NULL tstate->interp: should_audit() now ensures that it is
not NULL (even if tstate->interp cannot be NULL in practice).

PySys_AddAuditHook() now checks if tstate is not NULL to decide if
tstate can be used or not, and tstate is set to NULL if the runtime
is not initialized yet.

Use _PySys_Audit() in sysmodule.c.

2 files changed, 28 insertions, 1 deletions

diff --git a/Include/cpython/sysmodule.h b/Include/cpython/sysmodule.h
index 72d8ffe..1802b5b 100644
--- a/Include/cpython/sysmodule.h
+++ b/Include/cpython/sysmodule.h
@@ -13,7 +13,10 @@ PyAPI_FUNC(size_t) _PySys_GetSizeOf(PyObject *);
 
 typedef int(*Py_AuditHookFunction)(const char *, PyObject *, void *);
 
-PyAPI_FUNC(int) PySys_Audit(const char*, const char *, ...);
+PyAPI_FUNC(int) PySys_Audit(
+    const char *event,
+    const char *argFormat,
+    ...);
 PyAPI_FUNC(int) PySys_AddAuditHook(Py_AuditHookFunction, void*);
 
 #ifdef __cplusplus
diff --git a/Include/internal/pycore_sysmodule.h b/Include/internal/pycore_sysmodule.h
new file mode 100644
index 0000000..738a774
--- /dev/null
+++ b/Include/internal/pycore_sysmodule.h
@@ -0,0 +1,24 @@
+#ifndef Py_INTERNAL_SYSMODULE_H
+#define Py_INTERNAL_SYSMODULE_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+PyAPI_FUNC(int) _PySys_Audit(
+    PyThreadState *tstate,
+    const char *event,
+    const char *argFormat,
+    ...);
+
+/* We want minimal exposure of this function, so use extern rather than
+   PyAPI_FUNC() to not export the symbol. */
+extern void _PySys_ClearAuditHooks(PyThreadState *tstate);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_SYSMODULE_H */