Partial LSE: handle all kinds of infinite loops.
A subgraph could also have an infinite loop.
Test: 826-inifinite-loop
Bug: 196246395
Merged-In: Ifd1e1ae0f42dfe2cc156386fc166101c20748fc9
(cherry picked from commit 96dadefd24331f6808cb287048269ba772423c33)
Change-Id: I410ec26aefbc42629ba7dbe5a19a87399cefe396
diff --git a/compiler/optimizing/execution_subgraph.cc b/compiler/optimizing/execution_subgraph.cc
index 6d10566..66fdfcd 100644
--- a/compiler/optimizing/execution_subgraph.cc
+++ b/compiler/optimizing/execution_subgraph.cc
@@ -86,12 +86,6 @@
ScopedArenaVector<std::bitset<kMaxFilterableSuccessors>> results(
graph_->GetBlocks().size(), temporaries.Adapter(kArenaAllocLSA));
unreachable_blocks_.ClearAllBits();
- // TODO We should support infinite loops as well.
- if (UNLIKELY(graph_->GetExitBlock() == nullptr)) {
- // Infinite loop
- valid_ = false;
- return;
- }
// Fills up the 'results' map with what we need to add to update
// allowed_successors in order to prune sink nodes.
bool start_reaches_end = false;
@@ -170,8 +164,11 @@
<< "current path size: " << current_path.size()
<< " cur_block id: " << cur_block->GetBlockId() << " entry id "
<< graph_->GetEntryBlock()->GetBlockId();
- DCHECK(!visiting.IsBitSet(id))
- << "Somehow ended up in a loop! This should have been caught before now! " << id;
+ if (visiting.IsBitSet(id)) {
+ // TODO We should support infinite loops as well.
+ start_reaches_end = false;
+ break;
+ }
std::bitset<kMaxFilterableSuccessors>& result = results[id];
if (cur_block == graph_->GetExitBlock()) {
start_reaches_end = true;
diff --git a/test/826-infinite-loop/expected-stderr.txt b/test/826-infinite-loop/expected-stderr.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/826-infinite-loop/expected-stderr.txt
diff --git a/test/826-infinite-loop/expected-stdout.txt b/test/826-infinite-loop/expected-stdout.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/826-infinite-loop/expected-stdout.txt
diff --git a/test/826-infinite-loop/info.txt b/test/826-infinite-loop/info.txt
new file mode 100644
index 0000000..13a89d8
--- /dev/null
+++ b/test/826-infinite-loop/info.txt
@@ -0,0 +1,2 @@
+Regression test for partial escape elimination, which used to crash when
+visiting an infinite loop.
diff --git a/test/826-infinite-loop/src/Main.java b/test/826-infinite-loop/src/Main.java
new file mode 100644
index 0000000..85bcb28
--- /dev/null
+++ b/test/826-infinite-loop/src/Main.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+final class Main {
+ public static void main(String[] args) {
+ Object o = new Object();
+ if (args.length == 0) {
+ while (true) {
+ System.out.println(new Object());
+ }
+ }
+ }
+}
