From: Aaron Ballman <aaron@aaronballman.com>
Date: Fri, 24 Aug 2018 18:48:35 +0000 (+0000)
Subject: Thread safety analysis no longer hands when analyzing a self-referencing initializer.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8e7c1967e0729d3a9db41b1eeb2b3f73ee44f01c;p=clang

Thread safety analysis no longer hands when analyzing a self-referencing initializer.

This fixes PR38640.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@340636 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ThreadSafety.cpp b/lib/Analysis/ThreadSafety.cpp
index 74648dfb5e..88b3f3c2c1 100644
--- a/lib/Analysis/ThreadSafety.cpp
+++ b/lib/Analysis/ThreadSafety.cpp
@@ -1656,6 +1656,9 @@ void BuildLockset::checkAccess(const Expr *Exp, AccessKind AK,
     const auto *VD = dyn_cast<VarDecl>(DRE->getDecl()->getCanonicalDecl());
     if (VD && VD->isLocalVarDecl() && VD->getType()->isReferenceType()) {
       if (const auto *E = VD->getInit()) {
+        // Guard against self-initialization. e.g., int &i = i;
+        if (E == Exp)
+          break;
         Exp = E;
         continue;
       }
diff --git a/test/SemaCXX/warn-thread-safety-analysis.cpp b/test/SemaCXX/warn-thread-safety-analysis.cpp
index 50d0988228..29408e82b4 100644
--- a/test/SemaCXX/warn-thread-safety-analysis.cpp
+++ b/test/SemaCXX/warn-thread-safety-analysis.cpp
@@ -5503,3 +5503,11 @@ namespace ReturnScopedLockable {
     return ptr->f();
   }
 }
+
+namespace PR38640 {
+void f() {
+  // Self-referencing assignment previously caused an infinite loop when thread
+  // safety analysis was enabled.
+  int &i = i; // expected-warning {{reference 'i' is not yet bound to a value when used within its own initialization}}
+}
+}