gh-116088: Insert bottom checks after all sym_set_...() calls (#116089)

This changes the `sym_set_...()` functions to return a `bool` which is `false`
when the symbol is `bottom` after the operation.

All calls to such functions now check this result and go to `hit_bottom`,
a special error label that prints a different message and then reports
that it wasn't able to optimize the trace. No executor will be produced
in this case.

1 files changed, 27 insertions, 9 deletions

diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index 928c22da16b..aa19a50f09f 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -85,8 +85,12 @@ dummy_func(void) {
             sym_matches_type(right, &PyLong_Type)) {
             REPLACE_OP(this_instr, _NOP, 0, 0);
         }
-        sym_set_type(left, &PyLong_Type);
-        sym_set_type(right, &PyLong_Type);
+        if (!sym_set_type(left, &PyLong_Type)) {
+            goto hit_bottom;
+        }
+        if (!sym_set_type(right, &PyLong_Type)) {
+            goto hit_bottom;
+        }
     }
 
     op(_GUARD_BOTH_FLOAT, (left, right -- left, right)) {
@@ -94,8 +98,12 @@ dummy_func(void) {
             sym_matches_type(right, &PyFloat_Type)) {
             REPLACE_OP(this_instr, _NOP, 0 ,0);
         }
-        sym_set_type(left, &PyFloat_Type);
-        sym_set_type(right, &PyFloat_Type);
+        if (!sym_set_type(left, &PyFloat_Type)) {
+            goto hit_bottom;
+        }
+        if (!sym_set_type(right, &PyFloat_Type)) {
+            goto hit_bottom;
+        }
     }
 
     op(_GUARD_BOTH_UNICODE, (left, right -- left, right)) {
@@ -103,8 +111,12 @@ dummy_func(void) {
             sym_matches_type(right, &PyUnicode_Type)) {
             REPLACE_OP(this_instr, _NOP, 0 ,0);
         }
-        sym_set_type(left, &PyUnicode_Type);
-        sym_set_type(right, &PyUnicode_Type);
+        if (!sym_set_type(left, &PyUnicode_Type)) {
+            goto hit_bottom;
+        }
+        if (!sym_set_type(right, &PyUnicode_Type)) {
+            goto hit_bottom;
+        }
     }
 
     op(_BINARY_OP_ADD_INT, (left, right -- res)) {
@@ -365,14 +377,20 @@ dummy_func(void) {
 
 
     op(_CHECK_FUNCTION_EXACT_ARGS, (func_version/2, callable, self_or_null, unused[oparg] -- callable, self_or_null, unused[oparg])) {
-        sym_set_type(callable, &PyFunction_Type);
+        if (!sym_set_type(callable, &PyFunction_Type)) {
+            goto hit_bottom;
+        }
         (void)self_or_null;
         (void)func_version;
     }
 
     op(_CHECK_CALL_BOUND_METHOD_EXACT_ARGS, (callable, null, unused[oparg] -- callable, null, unused[oparg])) {
-        sym_set_null(null);
-        sym_set_type(callable, &PyMethod_Type);
+        if (!sym_set_null(null)) {
+            goto hit_bottom;
+        }
+        if (!sym_set_type(callable, &PyMethod_Type)) {
+            goto hit_bottom;
+        }
     }
 
     op(_INIT_CALL_PY_EXACT_ARGS, (callable, self_or_null, args[oparg] -- new_frame: _Py_UOpsAbstractFrame *)) {