[ReachableCode] Skip over ExprWithCleanups in isConfigurationValue

Summary: Fixes pr29152.

Reviewers: rsmith, pirama, krememek

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D24010

llvm-svn: 285657

clang/include/clang/AST/Stmt.h

@@ -387,6 +387,9 @@ class alignas(void *) Stmt {
   /// Skip past any implicit AST nodes which might surround this
   /// statement, such as ExprWithCleanups or ImplicitCastExpr nodes.
   Stmt *IgnoreImplicit();
+  const Stmt *IgnoreImplicit() const {
+    return const_cast<Stmt *>(this)->IgnoreImplicit();
+  }
 
   /// \brief Skip no-op (attributed, compound) container stmts and skip captured
   /// stmt at the top, if \a IgnoreCaptured is true.

clang/lib/Analysis/ReachableCode.cpp

@@ -164,6 +164,8 @@ static bool isConfigurationValue(const Stmt *S,
   if (!S)
     return false;
 
+  S = S->IgnoreImplicit();
+
   if (const Expr *Ex = dyn_cast<Expr>(S))
     S = Ex->IgnoreCasts();
 

clang/test/SemaCXX/PR29152.cpp

@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -Wunreachable-code -verify %s
+
+static const bool False = false;
+
+struct A {
+  ~A();
+  operator bool();
+};
+void Bar();
+
+void Foo() {
+  if (False && A()) {
+    Bar(); // expected-no-diagnostics
+  }
+}