From 17535c34bc7853f8e73dfdec2c4da49d78b37bea Mon Sep 17 00:00:00 2001
From: Archie Cobbs <acobbs@openjdk.org>
Date: Thu, 12 Oct 2023 22:39:03 +0000
Subject: [PATCH] 8317818: Combinatorial explosion during 'this' escape
 analysis

Reviewed-by: vromero
---
 .../tools/javac/comp/ThisEscapeAnalyzer.java  |  4 +--
 .../tools/javac/warnings/ThisEscape.java      | 30 +++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
index 2dd054619e0..0dd32fd8eca 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ThisEscapeAnalyzer.java
@@ -167,7 +167,7 @@ class ThisEscapeAnalyzer extends TreeScanner {
 
     /** Used to terminate recursion in {@link #invokeInvokable invokeInvokable()}.
      */
-    private final Set<Pair<JCTree, RefSet<Ref>>> invocations = new HashSet<>();
+    private final Set<Pair<JCMethodDecl, RefSet<Ref>>> invocations = new HashSet<>();
 
     /** Snapshot of {@link #callStack} where a possible 'this' escape occurs.
      *  If non-null, a 'this' escape warning has been found in the current
@@ -590,7 +590,7 @@ class ThisEscapeAnalyzer extends TreeScanner {
                 return;
 
             // Stop infinite recursion here
-            Pair<JCTree, RefSet<Ref>> invocation = Pair.of(site, refs.clone());
+            Pair<JCMethodDecl, RefSet<Ref>> invocation = Pair.of(methodInfo.declaration, refs.clone());
             if (!invocations.add(invocation))
                 return;
 
diff --git a/test/langtools/tools/javac/warnings/ThisEscape.java b/test/langtools/tools/javac/warnings/ThisEscape.java
index d6ae9f8e8f4..25402c2c547 100644
--- a/test/langtools/tools/javac/warnings/ThisEscape.java
+++ b/test/langtools/tools/javac/warnings/ThisEscape.java
@@ -617,4 +617,34 @@ public class ThisEscape {
                 ;
         }
     }
+
+    // Verify no infinite recursion loop occurs (JDK-8317818)
+    public static class ThisEscapeRecursionExplosion {
+        private Object obj;
+        public ThisEscapeRecursionExplosion() {
+            getObject();
+        }
+        private Object getObject() {
+            if (this.obj == null) {
+                this.obj = new Object();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+                getObject().hashCode();
+            }
+            return this.obj;
+        }
+    }
 }