gh-122595: Add more error checks in the compiler (GH-122596)

Author: serhiy-storchaka

Python/compile.c

@@ -505,21 +505,35 @@ dictbytype(PyObject *src, int scope_type, int flag, Py_ssize_t offset)
        deterministic, then the generated bytecode is not deterministic.
     */
     sorted_keys = PyDict_Keys(src);
-    if (sorted_keys == NULL)
+    if (sorted_keys == NULL) {
+        Py_DECREF(dest);
         return NULL;
+    }
     if (PyList_Sort(sorted_keys) != 0) {
         Py_DECREF(sorted_keys);
+        Py_DECREF(dest);
         return NULL;
     }
     num_keys = PyList_GET_SIZE(sorted_keys);
 
     for (key_i = 0; key_i < num_keys; key_i++) {
-        /* XXX this should probably be a macro in symtable.h */
-        long vi;
         k = PyList_GET_ITEM(sorted_keys, key_i);
         v = PyDict_GetItemWithError(src, k);
-        assert(v && PyLong_Check(v));
-        vi = PyLong_AS_LONG(v);
+        if (!v) {
+            if (!PyErr_Occurred()) {
+                PyErr_SetObject(PyExc_KeyError, k);
+            }
+            Py_DECREF(sorted_keys);
+            Py_DECREF(dest);
+            return NULL;
+        }
+        long vi = PyLong_AsLong(v);
+        if (vi == -1 && PyErr_Occurred()) {
+            Py_DECREF(sorted_keys);
+            Py_DECREF(dest);
+            return NULL;
+        }
+        /* XXX this should probably be a macro in symtable.h */
         scope = (vi >> SCOPE_OFFSET) & SCOPE_MASK;
 
         if (scope == scope_type || vi & flag) {
@@ -631,6 +645,7 @@ compiler_set_qualname(struct compiler *c)
 
             scope = _PyST_GetScope(parent->u_ste, mangled);
             Py_DECREF(mangled);
+            RETURN_IF_ERROR(scope);
             assert(scope != GLOBAL_IMPLICIT);
             if (scope == GLOBAL_EXPLICIT)
                 force_global = 1;
@@ -1648,7 +1663,7 @@ dict_lookup_arg(PyObject *dict, PyObject *name)
     if (v == NULL) {
         return ERROR;
     }
-    return PyLong_AS_LONG(v);
+    return PyLong_AsLong(v);
 }
 
 static int
@@ -1671,7 +1686,7 @@ compiler_lookup_arg(struct compiler *c, PyCodeObject *co, PyObject *name)
     else {
         arg = dict_lookup_arg(c->u->u_metadata.u_freevars, name);
     }
-    if (arg == -1) {
+    if (arg == -1 && !PyErr_Occurred()) {
         PyObject *freevars = _PyCode_GetFreevars(co);
         if (freevars == NULL) {
             PyErr_Clear();
@@ -4085,6 +4100,8 @@ compiler_nameop(struct compiler *c, location loc,
     case GLOBAL_EXPLICIT:
         optype = OP_GLOBAL;
         break;
+    case -1:
+        goto error;
     default:
         /* scope can be 0 */
         break;
@@ -4638,6 +4655,7 @@ is_import_originated(struct compiler *c, expr_ty e)
     }
 
     long flags = _PyST_GetSymbol(SYMTABLE(c)->st_top, e->v.Name.id);
+    RETURN_IF_ERROR(flags);
     return flags & DEF_IMPORT;
 }
 
@@ -4657,10 +4675,12 @@ can_optimize_super_call(struct compiler *c, expr_ty attr)
     PyObject *super_name = e->v.Call.func->v.Name.id;
     // detect statically-visible shadowing of 'super' name
     int scope = _PyST_GetScope(SYMTABLE_ENTRY(c), super_name);
+    RETURN_IF_ERROR(scope);
     if (scope != GLOBAL_IMPLICIT) {
         return 0;
     }
     scope = _PyST_GetScope(SYMTABLE(c)->st_top, super_name);
+    RETURN_IF_ERROR(scope);
     if (scope != 0) {
         return 0;
     }
@@ -4767,7 +4787,9 @@ maybe_optimize_method_call(struct compiler *c, expr_ty e)
     }
 
     /* Check that the base object is not something that is imported */
-    if (is_import_originated(c, meth->v.Attribute.value)) {
+    int ret = is_import_originated(c, meth->v.Attribute.value);
+    RETURN_IF_ERROR(ret);
+    if (ret) {
         return 0;
     }
 
@@ -4795,7 +4817,9 @@ maybe_optimize_method_call(struct compiler *c, expr_ty e)
     /* Alright, we can optimize the code. */
     location loc = LOC(meth);
 
-    if (can_optimize_super_call(c, meth)) {
+    ret = can_optimize_super_call(c, meth);
+    RETURN_IF_ERROR(ret);
+    if (ret) {
         RETURN_IF_ERROR(load_args_for_super(c, meth->v.Attribute.value));
         int opcode = asdl_seq_LEN(meth->v.Attribute.value->v.Call.args) ?
             LOAD_SUPER_METHOD : LOAD_ZERO_SUPER_METHOD;
@@ -5367,8 +5391,10 @@ push_inlined_comprehension_state(struct compiler *c, location loc,
     PyObject *k, *v;
     Py_ssize_t pos = 0;
     while (PyDict_Next(entry->ste_symbols, &pos, &k, &v)) {
-        assert(PyLong_Check(v));
-        long symbol = PyLong_AS_LONG(v);
+        long symbol = PyLong_AsLong(v);
+        if (symbol == -1 && PyErr_Occurred()) {
+            return ERROR;
+        }
         long scope = (symbol >> SCOPE_OFFSET) & SCOPE_MASK;
         PyObject *outv = PyDict_GetItemWithError(SYMTABLE_ENTRY(c)->ste_symbols, k);
         if (outv == NULL) {
@@ -5377,8 +5403,11 @@ push_inlined_comprehension_state(struct compiler *c, location loc,
             }
             outv = _PyLong_GetZero();
         }
-        assert(PyLong_CheckExact(outv));
-        long outsc = (PyLong_AS_LONG(outv) >> SCOPE_OFFSET) & SCOPE_MASK;
+        long outsymbol = PyLong_AsLong(outv);
+        if (outsymbol == -1 && PyErr_Occurred()) {
+            return ERROR;
+        }
+        long outsc = (outsymbol >> SCOPE_OFFSET) & SCOPE_MASK;
         // If a name has different scope inside than outside the comprehension,
         // we need to temporarily handle it with the right scope while
         // compiling the comprehension. If it's free in the comprehension
@@ -6064,14 +6093,18 @@ compiler_visit_expr(struct compiler *c, expr_ty e)
         return compiler_formatted_value(c, e);
     /* The following exprs can be assignment targets. */
     case Attribute_kind:
-        if (e->v.Attribute.ctx == Load && can_optimize_super_call(c, e)) {
-            RETURN_IF_ERROR(load_args_for_super(c, e->v.Attribute.value));
-            int opcode = asdl_seq_LEN(e->v.Attribute.value->v.Call.args) ?
-                LOAD_SUPER_ATTR : LOAD_ZERO_SUPER_ATTR;
-            ADDOP_NAME(c, loc, opcode, e->v.Attribute.attr, names);
-            loc = update_start_location_to_match_attr(c, loc, e);
-            ADDOP(c, loc, NOP);
-            return SUCCESS;
+        if (e->v.Attribute.ctx == Load) {
+            int ret = can_optimize_super_call(c, e);
+            RETURN_IF_ERROR(ret);
+            if (ret) {
+                RETURN_IF_ERROR(load_args_for_super(c, e->v.Attribute.value));
+                int opcode = asdl_seq_LEN(e->v.Attribute.value->v.Call.args) ?
+                    LOAD_SUPER_ATTR : LOAD_ZERO_SUPER_ATTR;
+                ADDOP_NAME(c, loc, opcode, e->v.Attribute.attr, names);
+                loc = update_start_location_to_match_attr(c, loc, e);
+                ADDOP(c, loc, NOP);
+                return SUCCESS;
+            }
         }
         RETURN_IF_ERROR(compiler_maybe_add_static_attribute_to_class(c, e));
         VISIT(c, expr, e->v.Attribute.value);
@@ -7300,7 +7333,8 @@ consts_dict_keys_inorder(PyObject *dict)
     if (consts == NULL)
         return NULL;
     while (PyDict_Next(dict, &pos, &k, &v)) {
-        i = PyLong_AS_LONG(v);
+        assert(PyLong_CheckExact(v));
+        i = PyLong_AsLong(v);
         /* The keys of the dictionary can be tuples wrapping a constant.
          * (see dict_add_o and _PyCode_ConstantKey). In that case
          * the object we want is always second. */