[3.12] GH-112215: Backport C recursion changes (GH-115083)

4 files changed, 8 insertions, 20 deletions

diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 6c95f07..ecaff20 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -13152,15 +13152,14 @@ PyObject* PyAST_mod2obj(mod_ty t)
 
     int starting_recursion_depth;
     /* Be careful here to prevent overflow. */
-    int COMPILER_STACK_FRAME_SCALE = 2;
     PyThreadState *tstate = _PyThreadState_GET();
     if (!tstate) {
         return NULL;
     }
     struct validator vstate;
-    vstate.recursion_limit = C_RECURSION_LIMIT * COMPILER_STACK_FRAME_SCALE;
+    vstate.recursion_limit = C_RECURSION_LIMIT;
     int recursion_depth = C_RECURSION_LIMIT - tstate->c_recursion_remaining;
-    starting_recursion_depth = recursion_depth * COMPILER_STACK_FRAME_SCALE;
+    starting_recursion_depth = recursion_depth;
     vstate.recursion_depth = starting_recursion_depth;
 
     PyObject *result = ast2obj_mod(state, &vstate, t);
diff --git a/Python/ast.c b/Python/ast.c
index 82d7bee..76f6556 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1038,9 +1038,6 @@ validate_type_params(struct validator *state, asdl_type_param_seq *tps)
 }
 
 
-/* See comments in symtable.c. */
-#define COMPILER_STACK_FRAME_SCALE 2
-
 int
 _PyAST_Validate(mod_ty mod)
 {
@@ -1057,9 +1054,9 @@ _PyAST_Validate(mod_ty mod)
     }
     /* Be careful here to prevent overflow. */
     int recursion_depth = C_RECURSION_LIMIT - tstate->c_recursion_remaining;
-    starting_recursion_depth = recursion_depth * COMPILER_STACK_FRAME_SCALE;
+    starting_recursion_depth = recursion_depth;
     state.recursion_depth = starting_recursion_depth;
-    state.recursion_limit = C_RECURSION_LIMIT * COMPILER_STACK_FRAME_SCALE;
+    state.recursion_limit = C_RECURSION_LIMIT;
 
     switch (mod->kind) {
     case Module_kind:
diff --git a/Python/ast_opt.c b/Python/ast_opt.c
index f8c4a95..e881b7f 100644
--- a/Python/ast_opt.c
+++ b/Python/ast_opt.c
@@ -1102,9 +1102,6 @@ astfold_type_param(type_param_ty node_, PyArena *ctx_, _PyASTOptimizeState *stat
 #undef CALL_OPT
 #undef CALL_SEQ
 
-/* See comments in symtable.c. */
-#define COMPILER_STACK_FRAME_SCALE 2
-
 int
 _PyAST_Optimize(mod_ty mod, PyArena *arena, _PyASTOptimizeState *state)
 {
@@ -1118,9 +1115,9 @@ _PyAST_Optimize(mod_ty mod, PyArena *arena, _PyASTOptimizeState *state)
     }
     /* Be careful here to prevent overflow. */
     int recursion_depth = C_RECURSION_LIMIT - tstate->c_recursion_remaining;
-    starting_recursion_depth = recursion_depth * COMPILER_STACK_FRAME_SCALE;
+    starting_recursion_depth = recursion_depth;
     state->recursion_depth = starting_recursion_depth;
-    state->recursion_limit = C_RECURSION_LIMIT * COMPILER_STACK_FRAME_SCALE;
+    state->recursion_limit = C_RECURSION_LIMIT;
 
     int ret = astfold_mod(mod, arena, state);
     assert(ret || PyErr_Occurred());
diff --git a/Python/symtable.c b/Python/symtable.c
index 7972984..cfa5bec 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -281,11 +281,6 @@ symtable_new(void)
     return NULL;
 }
 
-/* Using a scaling factor means this should automatically adjust when
-   the recursion limit is adjusted for small or large C stack allocations.
-*/
-#define COMPILER_STACK_FRAME_SCALE 2
-
 struct symtable *
 _PySymtable_Build(mod_ty mod, PyObject *filename, PyFutureFeatures *future)
 {
@@ -312,9 +307,9 @@ _PySymtable_Build(mod_ty mod, PyObject *filename, PyFutureFeatures *future)
     }
     /* Be careful here to prevent overflow. */
     int recursion_depth = C_RECURSION_LIMIT - tstate->c_recursion_remaining;
-    starting_recursion_depth = recursion_depth * COMPILER_STACK_FRAME_SCALE;
+    starting_recursion_depth = recursion_depth;
     st->recursion_depth = starting_recursion_depth;
-    st->recursion_limit = C_RECURSION_LIMIT * COMPILER_STACK_FRAME_SCALE;
+    st->recursion_limit = C_RECURSION_LIMIT;
 
     /* Make the initial symbol information gathering pass */
     if (!symtable_enter_block(st, &_Py_ID(top), ModuleBlock, (void *)mod, 0, 0, 0, 0)) {