ART: Allow PackedSwitch instructions with zero targets
Optimizing and the interpreter wrongly assumed that a PackedSwitch
always has at least one target. This patch removes the corresponding
DCHECKs and adds a regression test case.
This is a resubmission of CL I32b7033ed38de6f1d1a6ee5d5bf12f3a47c9b37e
Bug: 21863783
Change-Id: I04e6e124bdd16591ba27c79490e6ce183c36b691
(cherry picked from commit 2ef645ba50544b879a82ea30e606f18c9af98917)
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 58416ee..9468f36 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -1175,14 +1175,20 @@
}
void HGraphBuilder::BuildPackedSwitch(const Instruction& instruction, uint32_t dex_pc) {
+ // Verifier guarantees that the payload for PackedSwitch contains:
+ // (a) number of entries (may be zero)
+ // (b) first and lowest switch case value (entry 0, always present)
+ // (c) list of target pcs (entries 1 <= i <= N)
SwitchTable table(instruction, dex_pc, false);
// Value to test against.
HInstruction* value = LoadLocal(instruction.VRegA(), Primitive::kPrimInt);
+ // Retrieve number of entries.
uint16_t num_entries = table.GetNumEntries();
- // There should be at least one entry here.
- DCHECK_GT(num_entries, 0U);
+ if (num_entries == 0) {
+ return;
+ }
// Chained cmp-and-branch, starting from starting_key.
int32_t starting_key = table.GetEntryAt(0);
@@ -1194,6 +1200,10 @@
}
void HGraphBuilder::BuildSparseSwitch(const Instruction& instruction, uint32_t dex_pc) {
+ // Verifier guarantees that the payload for SparseSwitch contains:
+ // (a) number of entries (may be zero)
+ // (b) sorted key values (entries 0 <= i < N)
+ // (c) target pcs corresponding to the switch values (entries N <= i < 2*N)
SwitchTable table(instruction, dex_pc, true);
// Value to test against.
diff --git a/runtime/interpreter/interpreter_common.h b/runtime/interpreter/interpreter_common.h
index 6fafcd1..0124d90 100644
--- a/runtime/interpreter/interpreter_common.h
+++ b/runtime/interpreter/interpreter_common.h
@@ -295,7 +295,10 @@
int32_t test_val = shadow_frame.GetVReg(inst->VRegA_31t(inst_data));
DCHECK_EQ(switch_data[0], static_cast<uint16_t>(Instruction::kPackedSwitchSignature));
uint16_t size = switch_data[1];
- DCHECK_GT(size, 0);
+ if (size == 0) {
+ // Empty packed switch, move forward by 3 (size of PACKED_SWITCH).
+ return 3;
+ }
const int32_t* keys = reinterpret_cast<const int32_t*>(&switch_data[2]);
DCHECK(IsAligned<4>(keys));
int32_t first_key = keys[0];
diff --git a/test/501-regression-packed-switch/expected.txt b/test/501-regression-packed-switch/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/501-regression-packed-switch/expected.txt
diff --git a/test/501-regression-packed-switch/info.txt b/test/501-regression-packed-switch/info.txt
new file mode 100644
index 0000000..fbd93fa
--- /dev/null
+++ b/test/501-regression-packed-switch/info.txt
@@ -0,0 +1,2 @@
+Regression test for the interpreter and optimizing's builder which used
+to trip when compiled code contained a packed switch with no targets.
diff --git a/test/501-regression-packed-switch/smali/Test.smali b/test/501-regression-packed-switch/smali/Test.smali
new file mode 100644
index 0000000..8756ed5
--- /dev/null
+++ b/test/501-regression-packed-switch/smali/Test.smali
@@ -0,0 +1,29 @@
+#
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+.class public LTest;
+
+.super Ljava/lang/Object;
+
+.method public static EmptyPackedSwitch(I)I
+ .registers 1
+ packed-switch v0, :pswitch_data_6a
+ const/4 v0, 0x5
+ return v0
+
+ :pswitch_data_6a
+ .packed-switch 0x0
+ .end packed-switch
+.end method
diff --git a/test/501-regression-packed-switch/src/Main.java b/test/501-regression-packed-switch/src/Main.java
new file mode 100644
index 0000000..b80bc62
--- /dev/null
+++ b/test/501-regression-packed-switch/src/Main.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+
+public class Main {
+
+ // Workaround for b/18051191.
+ class InnerClass {}
+
+ public static void main(String args[]) throws Exception {
+ Class<?> c = Class.forName("Test");
+ Method m = c.getMethod("EmptyPackedSwitch", new Class[] { int.class });
+ Integer result = (Integer) m.invoke(null, new Integer(42));
+ if (result != 5) {
+ throw new Error("Expected 5, got " + result);
+ }
+ }
+}
