# HG changeset patch
# User vkempik
# Date 1491927478 -10800
# Node ID dcaab7b518c411e87f1f69776c0d6994d3549fcf
# Parent  c73c5d205d0a2368225c40f75bd3aa2c8e09a5f8
8173373: C1: NPE is thrown instead of LinkageError when accessing inaccessible field on NULL receiver
Summary: Deoptimize if receiver null check of unresolved field access fails to throw NoClassDefFoundError instead of NPE.
Reviewed-by: vlivanov

diff -r c73c5d205d0a -r dcaab7b518c4 src/share/vm/c1/c1_LIR.cpp
--- a/src/share/vm/c1/c1_LIR.cpp	Fri Apr 07 02:15:31 2017 +0900
+++ b/src/share/vm/c1/c1_LIR.cpp	Tue Apr 11 19:17:58 2017 +0300
@@ -1516,6 +1516,17 @@
   append(c);
 }
 
+void LIR_List::null_check(LIR_Opr opr, CodeEmitInfo* info, bool deoptimize_on_null) {
+  if (deoptimize_on_null) {
+    // Emit an explicit null check and deoptimize if opr is null
+    CodeStub* deopt = new DeoptimizeStub(info);
+    cmp(lir_cond_equal, opr, LIR_OprFact::oopConst(NULL));
+    branch(lir_cond_equal, T_OBJECT, deopt);
+  } else {
+    // Emit an implicit null check
+    append(new LIR_Op1(lir_null_check, opr, info));
+  }
+}
 
 void LIR_List::cas_long(LIR_Opr addr, LIR_Opr cmp_value, LIR_Opr new_value,
                         LIR_Opr t1, LIR_Opr t2, LIR_Opr result) {
diff -r c73c5d205d0a -r dcaab7b518c4 src/share/vm/c1/c1_LIR.hpp
--- a/src/share/vm/c1/c1_LIR.hpp	Fri Apr 07 02:15:31 2017 +0900
+++ b/src/share/vm/c1/c1_LIR.hpp	Tue Apr 11 19:17:58 2017 +0300
@@ -2153,7 +2153,7 @@
   void   pack64(LIR_Opr src, LIR_Opr dst) { append(new LIR_Op1(lir_pack64,   src, dst, T_LONG, lir_patch_none, NULL)); }
   void unpack64(LIR_Opr src, LIR_Opr dst) { append(new LIR_Op1(lir_unpack64, src, dst, T_LONG, lir_patch_none, NULL)); }
 
-  void null_check(LIR_Opr opr, CodeEmitInfo* info)         { append(new LIR_Op1(lir_null_check, opr, info)); }
+  void null_check(LIR_Opr opr, CodeEmitInfo* info, bool deoptimize_on_null = false);
   void throw_exception(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) {
     append(new LIR_Op2(lir_throw, exceptionPC, exceptionOop, LIR_OprFact::illegalOpr, info));
   }
diff -r c73c5d205d0a -r dcaab7b518c4 src/share/vm/c1/c1_LIRGenerator.cpp
--- a/src/share/vm/c1/c1_LIRGenerator.cpp	Fri Apr 07 02:15:31 2017 +0900
+++ b/src/share/vm/c1/c1_LIRGenerator.cpp	Tue Apr 11 19:17:58 2017 +0300
@@ -1700,8 +1700,10 @@
   if (x->needs_null_check() &&
       (needs_patching ||
        MacroAssembler::needs_explicit_null_check(x->offset()))) {
-    // emit an explicit null check because the offset is too large
-    __ null_check(object.result(), new CodeEmitInfo(info));
+    // Emit an explicit null check because the offset is too large.
+    // If the class is not loaded and the object is NULL, we need to deoptimize to throw a
+    // NoClassDefFoundError in the interpreter instead of an implicit NPE from compiled code.
+    __ null_check(object.result(), new CodeEmitInfo(info), /* deoptimize */ needs_patching);
   }
 
   LIR_Address* address;
@@ -1785,8 +1787,10 @@
       obj = new_register(T_OBJECT);
       __ move(LIR_OprFact::oopConst(NULL), obj);
     }
-    // emit an explicit null check because the offset is too large
-    __ null_check(obj, new CodeEmitInfo(info));
+    // Emit an explicit null check because the offset is too large.
+    // If the class is not loaded and the object is NULL, we need to deoptimize to throw a
+    // NoClassDefFoundError in the interpreter instead of an implicit NPE from compiled code.
+    __ null_check(obj, new CodeEmitInfo(info), /* deoptimize */ needs_patching);
   }
 
   LIR_Opr reg = rlock_result(x, field_type);
diff -r c73c5d205d0a -r dcaab7b518c4 test/compiler/c1/TestUnresolvedField.jasm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/c1/TestUnresolvedField.jasm	Tue Apr 11 19:17:58 2017 +0300
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2017, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+public class compiler/c1/TestUnresolvedField version 52:0 {
+    public static Method testGetField:"()V" stack 1 locals 1 {
+        aconst_null;
+        getfield Field T.f:I; // T does not exist
+        return;
+    }
+
+    public static Method testPutField:"()V" stack 2 locals 1 {
+        aconst_null;
+        iconst_0;
+        putfield Field T.f:I; // T does not exist
+        return;
+    }
+}
diff -r c73c5d205d0a -r dcaab7b518c4 test/compiler/c1/TestUnresolvedFieldMain.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/c1/TestUnresolvedFieldMain.java	Tue Apr 11 19:17:58 2017 +0300
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2017, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8173373
+ * @compile TestUnresolvedField.jasm
+ * @run main/othervm -XX:TieredStopAtLevel=1 -Xcomp
+ *                   -XX:CompileCommand=compileonly,compiler.c1.TestUnresolvedField::test*
+ *                   compiler.c1.TestUnresolvedFieldMain
+ */
+
+package compiler.c1;
+
+public class TestUnresolvedFieldMain {
+    public static void main(String[] args) {
+        try {
+          TestUnresolvedField.testGetField();
+        } catch (java.lang.NoClassDefFoundError error) {
+          // Expected
+        }
+        try {
+          TestUnresolvedField.testPutField();
+        } catch (java.lang.NoClassDefFoundError error) {
+          // Expected
+        }
+    }
+}