From ccbcea830dc8d8b99c919d491adc60f7b4e8f28d Mon Sep 17 00:00:00 2001
From: Coleen Phillimore <coleenp@openjdk.org>
Date: Wed, 4 Jan 2023 14:42:15 +0000
Subject: [PATCH] 8299326: LinkResolver::resolve_field resolved_klass cannot be
 null

Reviewed-by: iklam, fparain
---
 .../share/interpreter/linkResolver.cpp        |  9 ++----
 .../share/interpreter/linkResolver.hpp        | 31 ++++++++++---------
 2 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/src/hotspot/share/interpreter/linkResolver.cpp b/src/hotspot/share/interpreter/linkResolver.cpp
index db1ed705d13..c62eb622d38 100644
--- a/src/hotspot/share/interpreter/linkResolver.cpp
+++ b/src/hotspot/share/interpreter/linkResolver.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -814,7 +814,7 @@ static void trace_method_resolution(const char* prefix,
   st->print("%s%s, compile-time-class:%s, method:%s, method_holder:%s, access_flags: ",
             prefix,
             (klass == NULL ? "<NULL>" : klass->internal_name()),
-            (resolved_klass == NULL ? "<NULL>" : resolved_klass->internal_name()),
+            resolved_klass->internal_name(),
             Method::name_and_sig_as_C_string(resolved_klass,
                                              method->name(),
                                              method->signature()),
@@ -970,11 +970,6 @@ void LinkResolver::resolve_field(fieldDescriptor& fd,
   Symbol* field = link_info.name();
   Symbol* sig = link_info.signature();
 
-  if (resolved_klass == NULL) {
-    ResourceMark rm(THREAD);
-    THROW_MSG(vmSymbols::java_lang_NoSuchFieldError(), field->as_C_string());
-  }
-
   // Resolve instance field
   Klass* sel_klass = resolved_klass->find_field(field, sig, &fd);
   // check if field exists; i.e., if a klass containing the field def has been selected
diff --git a/src/hotspot/share/interpreter/linkResolver.hpp b/src/hotspot/share/interpreter/linkResolver.hpp
index b1a7274c6bc..9686495c0af 100644
--- a/src/hotspot/share/interpreter/linkResolver.hpp
+++ b/src/hotspot/share/interpreter/linkResolver.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -154,26 +154,29 @@ class LinkInfo : public StackObj {
            AccessCheck check_access = AccessCheck::required,
            LoaderConstraintCheck check_loader_constraints = LoaderConstraintCheck::required,
            constantTag tag = JVM_CONSTANT_Invalid) :
-    _name(name),
-    _signature(signature), _resolved_klass(resolved_klass), _current_klass(current_klass), _current_method(methodHandle()),
-    _check_access(check_access == AccessCheck::required),
-    _check_loader_constraints(check_loader_constraints == LoaderConstraintCheck::required), _tag(tag) {}
+      _name(name),
+      _signature(signature),
+      _resolved_klass(resolved_klass),
+      _current_klass(current_klass),
+      _current_method(methodHandle()),
+      _check_access(check_access == AccessCheck::required),
+      _check_loader_constraints(check_loader_constraints == LoaderConstraintCheck::required),
+      _tag(tag) {
+    assert(_resolved_klass != nullptr, "must always have a resolved_klass");
+  }
 
   LinkInfo(Klass* resolved_klass, Symbol* name, Symbol* signature, const methodHandle& current_method,
            AccessCheck check_access = AccessCheck::required,
            LoaderConstraintCheck check_loader_constraints = LoaderConstraintCheck::required,
            constantTag tag = JVM_CONSTANT_Invalid) :
-    _name(name),
-    _signature(signature), _resolved_klass(resolved_klass), _current_klass(current_method->method_holder()), _current_method(current_method),
-    _check_access(check_access == AccessCheck::required),
-    _check_loader_constraints(check_loader_constraints == LoaderConstraintCheck::required), _tag(tag) {}
+    LinkInfo(resolved_klass, name, signature, current_method->method_holder(), check_access, check_loader_constraints, tag) {
+    _current_method = current_method;
+  }
 
-
-  // Case where we just find the method and don't check access against the current class
+  // Case where we just find the method and don't check access against the current class, used by JavaCalls
   LinkInfo(Klass* resolved_klass, Symbol*name, Symbol* signature) :
-    _name(name),
-    _signature(signature), _resolved_klass(resolved_klass), _current_klass(NULL), _current_method(methodHandle()),
-    _check_access(false), _check_loader_constraints(false), _tag(JVM_CONSTANT_Invalid) {}
+    LinkInfo(resolved_klass, name, signature, nullptr, AccessCheck::skip, LoaderConstraintCheck::skip,
+             JVM_CONSTANT_Invalid) {}
 
   // accessors
   Symbol* name() const                  { return _name; }