From c7e7dd28631dae5aeaa6df29aa5b703fb182d0eb Mon Sep 17 00:00:00 2001
From: George Karpenkov <ekarpenkov@apple.com>
Date: Tue, 11 Dec 2018 01:14:17 +0000
Subject: [PATCH] [analyzer] Remove memoization from
 RunLoopAutoreleaseLeakChecker

Memoization dose not seem to be necessary, as other statement visitors
run just fine without it,
and in fact seems to be causing memory corruptions.
Just removing it instead of investigating the root cause.

rdar://45945002

Differential Revision: https://reviews.llvm.org/D54921

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@348822 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../RunLoopAutoreleaseLeakChecker.cpp         | 34 +++++--------------
 1 file changed, 8 insertions(+), 26 deletions(-)

diff --git a/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp b/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp
index 55516a34d1..3f3477b928 100644
--- a/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp
@@ -58,13 +58,12 @@ public:
 
 } // end anonymous namespace
 
-
-using TriBoolTy = Optional<bool>;
-using MemoizationMapTy = llvm::DenseMap<const Stmt *, Optional<TriBoolTy>>;
-
-static TriBoolTy
-seenBeforeRec(const Stmt *Parent, const Stmt *A, const Stmt *B,
-              MemoizationMapTy &Memoization) {
+/// \return Whether {@code A} occurs before {@code B} in traversal of
+/// {@code Parent}.
+/// Conceptually a very incomplete/unsound approximation of happens-before
+/// relationship (A is likely to be evaluated before B),
+/// but useful enough in this case.
+static bool seenBefore(const Stmt *Parent, const Stmt *A, const Stmt *B) {
   for (const Stmt *C : Parent->children()) {
     if (!C) continue;
 
@@ -74,26 +73,9 @@ seenBeforeRec(const Stmt *Parent, const Stmt *A, const Stmt *B,
     if (C == B)
       return false;
 
-    Optional<TriBoolTy> &Cached = Memoization[C];
-    if (!Cached)
-      Cached = seenBeforeRec(C, A, B, Memoization);
-
-    if (Cached->hasValue())
-      return Cached->getValue();
+    return seenBefore(C, A, B);
   }
-
-  return None;
-}
-
-/// \return Whether {@code A} occurs before {@code B} in traversal of
-/// {@code Parent}.
-/// Conceptually a very incomplete/unsound approximation of happens-before
-/// relationship (A is likely to be evaluated before B),
-/// but useful enough in this case.
-static bool seenBefore(const Stmt *Parent, const Stmt *A, const Stmt *B) {
-  MemoizationMapTy Memoization;
-  TriBoolTy Val = seenBeforeRec(Parent, A, B, Memoization);
-  return Val.getValue();
+  return false;
 }
 
 static void emitDiagnostics(BoundNodes &Match,
-- 
2.40.0