bpo-45953: Statically initialize all the non-object PyInterpreterState fields we can. (gh-30589)

https://bugs.python.org/issue45953

5 files changed, 40 insertions, 26 deletions

diff --git a/Include/internal/pycore_gc.h b/Include/internal/pycore_gc.h
index a23dca8..56a23e9 100644
--- a/Include/internal/pycore_gc.h
+++ b/Include/internal/pycore_gc.h
@@ -134,6 +134,7 @@ struct _gc_runtime_state {
     /* Current call-stack depth of tp_dealloc calls. */
     int trash_delete_nesting;
 
+    /* Is automatic collection enabled? */
     int enabled;
     int debug;
     /* linked lists of container objects */
@@ -161,6 +162,7 @@ struct _gc_runtime_state {
     Py_ssize_t long_lived_pending;
 };
 
+
 extern void _PyGC_InitState(struct _gc_runtime_state *);
 
 extern Py_ssize_t _PyGC_CollectNoFail(PyThreadState *tstate);
diff --git a/Include/internal/pycore_runtime_init.h b/Include/internal/pycore_runtime_init.h
index aa66120..72ca346 100644
--- a/Include/internal/pycore_runtime_init.h
+++ b/Include/internal/pycore_runtime_init.h
@@ -32,9 +32,36 @@ extern "C" {
         ._main_interpreter = _PyInterpreterState_INIT, \
     }
 
+#ifdef HAVE_DLOPEN
+#  include <dlfcn.h>
+#  if HAVE_DECL_RTLD_NOW
+#    define _Py_DLOPEN_FLAGS RTLD_NOW
+#  else
+#    define _Py_DLOPEN_FLAGS RTLD_LAZY
+#  endif
+#  define DLOPENFLAGS_INIT .dlopenflags = _Py_DLOPEN_FLAGS,
+#else
+#  define _Py_DLOPEN_FLAGS 0
+#  define DLOPENFLAGS_INIT
+#endif
+
 #define _PyInterpreterState_INIT \
     { \
         ._static = 1, \
+        .id_refcount = -1, \
+        DLOPENFLAGS_INIT \
+        .ceval = { \
+            .recursion_limit = Py_DEFAULT_RECURSION_LIMIT, \
+        }, \
+        .gc = { \
+            .enabled = 1, \
+            .generations = { \
+                /* .head is set in _PyGC_InitState(). */ \
+                { .threshold = 700, }, \
+                { .threshold = 10, }, \
+                { .threshold = 10, }, \
+            }, \
+        }, \
         ._initial_thread = _PyThreadState_INIT, \
     }
 
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index e22f031..16f8c2b 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -139,24 +139,20 @@ get_gc_state(void)
 void
 _PyGC_InitState(GCState *gcstate)
 {
-    gcstate->enabled = 1; /* automatic collection enabled? */
-
-#define _GEN_HEAD(n) GEN_HEAD(gcstate, n)
-    struct gc_generation generations[NUM_GENERATIONS] = {
-        /* PyGC_Head,                                    threshold,    count */
-        {{(uintptr_t)_GEN_HEAD(0), (uintptr_t)_GEN_HEAD(0)},   700,        0},
-        {{(uintptr_t)_GEN_HEAD(1), (uintptr_t)_GEN_HEAD(1)},   10,         0},
-        {{(uintptr_t)_GEN_HEAD(2), (uintptr_t)_GEN_HEAD(2)},   10,         0},
-    };
+#define INIT_HEAD(GEN) \
+    do { \
+        GEN.head._gc_next = (uintptr_t)&GEN.head; \
+        GEN.head._gc_prev = (uintptr_t)&GEN.head; \
+    } while (0)
+
     for (int i = 0; i < NUM_GENERATIONS; i++) {
-        gcstate->generations[i] = generations[i];
+        assert(gcstate->generations[i].count == 0);
+        INIT_HEAD(gcstate->generations[i]);
     };
     gcstate->generation0 = GEN_HEAD(gcstate, 0);
-    struct gc_generation permanent_generation = {
-          {(uintptr_t)&gcstate->permanent_generation.head,
-           (uintptr_t)&gcstate->permanent_generation.head}, 0, 0
-    };
-    gcstate->permanent_generation = permanent_generation;
+    INIT_HEAD(gcstate->permanent_generation);
+
+#undef INIT_HEAD
 }
 
 
diff --git a/Python/ceval.c b/Python/ceval.c
index eed902f..70a7750 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -748,8 +748,6 @@ _PyEval_InitRuntimeState(struct _ceval_runtime_state *ceval)
 void
 _PyEval_InitState(struct _ceval_state *ceval, PyThread_type_lock pending_lock)
 {
-    ceval->recursion_limit = Py_DEFAULT_RECURSION_LIMIT;
-
     struct _pending_calls *pending = &ceval->pending;
     assert(pending->lock == NULL);
 
diff --git a/Python/pystate.c b/Python/pystate.c
index 2315685..4b698f2 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -281,7 +281,6 @@ init_interpreter(PyInterpreterState *interp,
 
     assert(id > 0 || (id == 0 && interp == runtime->interpreters.main));
     interp->id = id;
-    interp->id_refcount = -1;
 
     assert(runtime->interpreters.head == interp);
     assert(next != NULL || (interp == runtime->interpreters.main));
@@ -291,14 +290,6 @@ init_interpreter(PyInterpreterState *interp,
     _PyGC_InitState(&interp->gc);
     PyConfig_InitPythonConfig(&interp->config);
     _PyType_InitCache(interp);
-    interp->eval_frame = NULL;
-#ifdef HAVE_DLOPEN
-#if HAVE_DECL_RTLD_NOW
-    interp->dlopenflags = RTLD_NOW;
-#else
-    interp->dlopenflags = RTLD_LAZY;
-#endif
-#endif
 
     interp->_initialized = 1;
 }