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
--- a/hotspot/src/share/vm/c1/c1_LIR.cpp Tue Jan 31 01:11:40 2017 +0300
+++ b/hotspot/src/share/vm/c1/c1_LIR.cpp Tue Jan 31 18:42:45 2017 +0100
@@ -1413,6 +1413,17 @@
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, Deoptimization::Reason_null_check, Deoptimization::Action_none);
+ 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) {
--- a/hotspot/src/share/vm/c1/c1_LIR.hpp Tue Jan 31 01:11:40 2017 +0300
+++ b/hotspot/src/share/vm/c1/c1_LIR.hpp Tue Jan 31 18:42:45 2017 +0100
@@ -2113,7 +2113,7 @@
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));
}
--- a/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Jan 31 01:11:40 2017 +0300
+++ b/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Jan 31 18:42:45 2017 +0100
@@ -1752,8 +1752,10 @@
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;
@@ -1838,8 +1840,10 @@
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);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/c1/TestUnresolvedField.jasm Tue Jan 31 18:42:45 2017 +0100
@@ -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;
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/c1/TestUnresolvedFieldMain.java Tue Jan 31 18:42:45 2017 +0100
@@ -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
+ }
+ }
+}