Avoid trying to read the code for shim frames

Author: godlygeek

src/pystack/_pystack/pycode.cpp

@@ -133,6 +133,7 @@ getLocationInfo(
                 tlbc_entries + sizeof(tlbc_size),
                 tlbc_size * sizeof(uintptr_t),
                 vec.data());
+        LOG(DEBUG) << "tlbc_index=" << tlbc_index << " tlbc_size=" << tlbc_size;
         uintptr_t code_adaptive_actual = vec[tlbc_index];
         ptrdiff_t addrq =
                 (reinterpret_cast<uint16_t*>(last_instruction_index)

src/pystack/_pystack/pyframe.cpp

@@ -29,10 +29,10 @@ FrameObject::FrameObject(
     if (d_is_shim) {
         LOG(DEBUG) << "Skipping over a shim frame inserted by the interpreter";
         next_frame_no = frame_no;
+    } else {
+        d_code = getCode(manager, frame);
     }
 
-    d_code = getCode(manager, frame);
-
     auto prev_addr = frame.getField(&py_frame_v::o_back);
     LOG(DEBUG) << std::hex << std::showbase << "Previous frame address: " << prev_addr;
     if (prev_addr) {