r247740 - Don't crash when passing &@selector to a _Nonnull parameter. Fixes PR24774.

[Nico Weber via cfe-commits]

Author: nico
Date: Tue Sep 15 18:17:17 2015
New Revision: 247740

URL: http://llvm.org/viewvc/llvm-project?rev=247740&view=rev
Log:
Don't crash when passing &@selector to a _Nonnull parameter. Fixes PR24774.

The root cause here is that ObjCSelectorExpr is an rvalue, yet it can have its
address taken.  That's kind of awkward, but fixing this is awkward in other
ways, see https://llvm.org/bugs/show_bug.cgi?id=24774#c16 .  For now, just
fix the crash.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/SemaObjCXX/sel-address.mm

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=247740&r1=247739&r2=247740&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Tue Sep 15 18:17:17 2015
@@ -4557,12 +4557,13 @@ public:
 } // end anonymous namespace
 
 /// Evaluate an expression as an lvalue. This can be legitimately called on
-/// expressions which are not glvalues, in two cases:
+/// expressions which are not glvalues, in three cases:
 ///  * function designators in C, and
 ///  * "extern void" objects
+///  * @selector() expressions in Objective-C
 static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info) {
   assert(E->isGLValue() || E->getType()->isFunctionType() ||
-         E->getType()->isVoidType());
+         E->getType()->isVoidType() || isa<ObjCSelectorExpr>(E));
   return LValueExprEvaluator(Info, Result).Visit(E);
 }
 

Modified: cfe/trunk/test/SemaObjCXX/sel-address.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjCXX/sel-address.mm?rev=247740&r1=247739&r2=247740&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjCXX/sel-address.mm (original)
+++ cfe/trunk/test/SemaObjCXX/sel-address.mm Tue Sep 15 18:17:17 2015
@@ -2,7 +2,8 @@
 // pr7390
 
 void f(const SEL& v2) {}
-void g() {
+void g(SEL* _Nonnull);
+void h() {
   f(@selector(dealloc));
 
   SEL s = @selector(dealloc);
@@ -11,4 +12,8 @@ void g() {
   @selector(dealloc) = s;  // expected-error {{expression is not assignable}}
 
   SEL* ps2 = &@selector(dealloc);
+
+  // Shouldn't crash.
+  g(&@selector(foo));
 }
+