From bbed8cfe80cd27d3a47d877c7608d9be4e487d97 Mon Sep 17 00:00:00 2001
From: Aaron Puchert <aaronpuchert@alice-dsl.net>
Date: Fri, 30 Oct 2020 00:35:14 +0100
Subject: [PATCH] Thread safety analysis: Consider static class members as
 inaccessible

This fixes the issue pointed out in D84604#2363134. For now we exclude
static members completely, we'll take them into account later.
---
 clang/lib/Analysis/ThreadSafety.cpp           | 10 +++++--
 .../SemaCXX/warn-thread-safety-negative.cpp   | 27 +++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
index 65d410a65ba4..21583e92c72d 100644
--- a/clang/lib/Analysis/ThreadSafety.cpp
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -1269,10 +1269,16 @@ bool ThreadSafetyAnalyzer::inCurrentScope(const CapabilityExpr &CapE) {
   const threadSafety::til::SExpr *SExp = CapE.sexpr();
   assert(SExp && "Null expressions should be ignored");
 
-  // Global variables are always in scope.
   if (const auto *LP = dyn_cast<til::LiteralPtr>(SExp)) {
     const ValueDecl *VD = LP->clangDecl();
-    return VD->isDefinedOutsideFunctionOrMethod();
+    // Variables defined in a function are always inaccessible.
+    if (!VD->isDefinedOutsideFunctionOrMethod())
+      return false;
+    // For now we consider static class members to be inaccessible.
+    if (isa<CXXRecordDecl>(VD->getDeclContext()))
+      return false;
+    // Global variables are always in scope.
+    return true;
   }
 
   // Members are in scope from methods of the same class.
diff --git a/clang/test/SemaCXX/warn-thread-safety-negative.cpp b/clang/test/SemaCXX/warn-thread-safety-negative.cpp
index d7db5f402d11..9eabd67e4fc7 100644
--- a/clang/test/SemaCXX/warn-thread-safety-negative.cpp
+++ b/clang/test/SemaCXX/warn-thread-safety-negative.cpp
@@ -118,6 +118,33 @@ void testNamespaceGlobals() EXCLUSIVE_LOCKS_REQUIRED(!globalMutex) {
   ns::fq(); // expected-warning {{calling function 'fq' requires negative capability '!globalMutex'}}
 }
 
+class StaticMembers {
+public:
+  void pub() EXCLUSIVE_LOCKS_REQUIRED(!publicMutex);
+  void prot() EXCLUSIVE_LOCKS_REQUIRED(!protectedMutex);
+  void priv() EXCLUSIVE_LOCKS_REQUIRED(!privateMutex);
+  void test() {
+    pub();
+    prot();
+    priv();
+  }
+
+  static Mutex publicMutex;
+
+protected:
+  static Mutex protectedMutex;
+
+private:
+  static Mutex privateMutex;
+};
+
+void testStaticMembers() {
+  StaticMembers x;
+  x.pub();
+  x.prot();
+  x.priv();
+}
+
 }  // end namespace ScopeTest
 
 namespace DoubleAttribute {