Misc fixes/improvements

src/runtime/objmodel.cpp

@@ -2578,7 +2578,8 @@ template <ExceptionStyle S> BoxedInt* lenInternal(Box* obj, LenRewriteArgs* rewr
 
     if (rtn == NULL) {
         if (S == CAPI) {
-            PyErr_Format(TypeError, "object of type '%s' has no len()", getTypeName(obj));
+            if (!PyErr_Occurred())
+                PyErr_Format(TypeError, "object of type '%s' has no len()", getTypeName(obj));
             return NULL;
         } else
             raiseExcHelper(TypeError, "object of type '%s' has no len()", getTypeName(obj));
@@ -3694,7 +3695,8 @@ Box* runtimeCallInternal(Box* obj, CallRewriteArgs* rewrite_args, ArgPassSpec ar
 
         if (!rtn) {
             if (S == CAPI) {
-                PyErr_Format(TypeError, "'%s' object is not callable", getTypeName(obj));
+                if (!PyErr_Occurred())
+                    PyErr_Format(TypeError, "'%s' object is not callable", getTypeName(obj));
                 return NULL;
             } else
                 raiseExcHelper(TypeError, "'%s' object is not callable", getTypeName(obj));
@@ -4689,7 +4691,7 @@ extern "C" Box* getitem_capi(Box* target, Box* slice) noexcept {
 
         if (!rewrite_args.out_success) {
             rewriter.reset(NULL);
-        } else {
+        } else if (rtn) {
             rewriter->commitReturning(rewrite_args.out_rtn);
         }
     } else {

src/runtime/tuple.cpp

@@ -143,7 +143,7 @@ template <ExceptionStyle S> Box* tupleGetitem(BoxedTuple* self, Box* slice) {
         }
     }
 
-    assert(self->cls == tuple_cls);
+    assert(isSubclass(self->cls, tuple_cls));
 
     if (PyIndex_Check(slice)) {
         Py_ssize_t i = PyNumber_AsSsize_t(slice, PyExc_IndexError);

src/runtime/util.cpp

@@ -41,11 +41,11 @@ void parseSlice(BoxedSlice* slice, int size, i64* out_start, i64* out_stop, i64*
         throwCAPIException();
 }
 
-bool isSliceIndex(Box* b) {
+bool isSliceIndex(Box* b) noexcept {
     return b->cls == none_cls || b->cls == int_cls || PyIndex_Check(b);
 }
 
-void adjustNegativeIndicesOnObject(Box* obj, i64* start_out, i64* stop_out) {
+void adjustNegativeIndicesOnObject(Box* obj, i64* start_out, i64* stop_out) noexcept {
     i64 start = *start_out;
     i64 stop = *stop_out;
     PySequenceMethods* m;

src/runtime/util.h

@@ -36,9 +36,9 @@ inline void sliceIndex(Box* b, int64_t* out) {
         throwCAPIException();
 }
 
-bool isSliceIndex(Box* b);
+bool isSliceIndex(Box* b) noexcept;
 
-void adjustNegativeIndicesOnObject(Box* obj, i64* start, i64* stop);
+void adjustNegativeIndicesOnObject(Box* obj, i64* start, i64* stop) noexcept;
 
 // Adjust the start and stop bounds of the sequence we are slicing to its size.
 // Ensure stop >= start and remain within bounds.

test/tests/varargs_ics.py

 # run_args: -n
-# statcheck: 1 <= noninit_count("slowpath_runtimecall") < 20
+# statcheck: 1 <= noninit_count("slowpath_runtimecall") + noninit_count("slowpath_runtimecall_capi") < 20
 
 # Make sure we can patch some basic varargs cases