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.

Author: vstinner

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

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 */

Makefile.pre.in

@@ -1101,6 +1101,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_pylifecycle.h \
 		$(srcdir)/Include/internal/pycore_pymem.h \
 		$(srcdir)/Include/internal/pycore_pystate.h \
+		$(srcdir)/Include/internal/pycore_sysmodule.h \
 		$(srcdir)/Include/internal/pycore_traceback.h \
 		$(srcdir)/Include/internal/pycore_tupleobject.h \
 		$(srcdir)/Include/internal/pycore_warnings.h \

PCbuild/pythoncore.vcxproj

@@ -183,6 +183,7 @@
     <ClInclude Include="..\Include\internal\pycore_pylifecycle.h" />
     <ClInclude Include="..\Include\internal\pycore_pymem.h" />
     <ClInclude Include="..\Include\internal\pycore_pystate.h" />
+    <ClInclude Include="..\Include\internal\pycore_sysmodule.h" />
     <ClInclude Include="..\Include\internal\pycore_traceback.h" />
     <ClInclude Include="..\Include\internal\pycore_tupleobject.h" />
     <ClInclude Include="..\Include\internal\pycore_warnings.h" />

PCbuild/pythoncore.vcxproj.filters

@@ -252,6 +252,9 @@
     <ClInclude Include="..\Include\internal\pycore_pystate.h">
       <Filter>Include</Filter>
     </ClInclude>
+    <ClInclude Include="..\Include\internal\pycore_sysmodule.h">
+      <Filter>Include</Filter>
+    </ClInclude>
     <ClInclude Include="..\Include\internal\pycore_traceback.h">
       <Filter>Include</Filter>
     </ClInclude>

Python/pylifecycle.c

@@ -16,6 +16,7 @@
 #include "pycore_pylifecycle.h"
 #include "pycore_pymem.h"
 #include "pycore_pystate.h"
+#include "pycore_sysmodule.h"
 #include "pycore_traceback.h"
 #include "grammar.h"
 #include "node.h"
@@ -1409,11 +1410,7 @@ Py_FinalizeEx(void)
     _PyGC_CollectIfEnabled();
 
     /* Clear all loghooks */
-    /* We want minimal exposure of this function, so define the extern
-     * here. The linker should discover the correct function without
-     * exporting a symbol. */
-    extern void _PySys_ClearAuditHooks(void);
-    _PySys_ClearAuditHooks();
+    _PySys_ClearAuditHooks(tstate);
 
     /* Destroy all modules */
     _PyImport_Cleanup(tstate);