[cfe-commits] r166156 - in /cfe/trunk: lib/AST/ExprConstant.cpp test/CodeGenCXX/typeid-cxx11.cpp test/SemaCXX/constant-expression-cxx11.cpp

[Richard Smith]

Author: rsmith
Date: Wed Oct 17 18:52:07 2012
New Revision: 166156

URL: http://llvm.org/viewvc/llvm-project?rev=166156&view=rev
Log:
DR1535: only potentially-evaluated typeid expressions are disallowed in constant
expressions, not *any* typeid on a polymorphic class type.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/CodeGenCXX/typeid-cxx11.cpp
    cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: 
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=166156&r1=166155&r2=166156&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Wed Oct 17 18:52:07 2012
@@ -2886,19 +2886,13 @@
 }
 
 bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
-  if (E->isTypeOperand())
+  if (!E->isPotentiallyEvaluated())
     return Success(E);
-  CXXRecordDecl *RD = E->getExprOperand()->getType()->getAsCXXRecordDecl();
-  // FIXME: The standard says "a typeid expression whose operand is of a
-  // polymorphic class type" is not a constant expression, but it probably
-  // means "a typeid expression whose operand is potentially evaluated".
-  if (RD && RD->isPolymorphic()) {
-    Info.Diag(E, diag::note_constexpr_typeid_polymorphic)
-      << E->getExprOperand()->getType()
-      << E->getExprOperand()->getSourceRange();
-    return false;
-  }
-  return Success(E);
+
+  Info.Diag(E, diag::note_constexpr_typeid_polymorphic)
+    << E->getExprOperand()->getType()
+    << E->getExprOperand()->getSourceRange();
+  return false;
 }
 
 bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {

Modified: cfe/trunk/test/CodeGenCXX/typeid-cxx11.cpp
URL: 
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/typeid-cxx11.cpp?rev=166156&r1=166155&r2=166156&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/typeid-cxx11.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/typeid-cxx11.cpp Wed Oct 17 18:52:07 2012
@@ -18,13 +18,15 @@
 struct B : virtual A {};
 struct C { int n; };
 
-// FIXME: check we produce a constant array for this, once we support IRGen of
-// folded structs and arrays.
+// CHECK: @_ZN5Test1L5itemsE = internal constant [4 x {{.*}}] [{{.*}} 
@_ZTIN5Test11AE {{.*}}, {{.*}}, {{.*}} @_ZN5Test19make_implINS_1AEEEPvv }, 
{{.*}} @_ZTIN5Test11BE {{.*}} @_ZN5Test19make_implINS_1BEEEPvv {{.*}} 
@_ZTIN5Test11CE {{.*}} @_ZN5Test19make_implINS_1CEEEPvv {{.*}} @_ZTIi {{.*}} 
@_ZN5Test19make_implIiEEPvv }]
 constexpr Item items[] = {
   item<A>("A"), item<B>("B"), item<C>("C"), item<int>("int")
 };
 
-// CHECK: @_ZN5Test11xE = constant %"class.std::type_info"* bitcast (i8** 
@_ZTIN5Test11AE to %"class.std::type_info"*), align 8
+// CHECK: @_ZN5Test11xE = constant %"class.std::type_info"* bitcast ({{.*}}* 
@_ZTIN5Test11AE to %"class.std::type_info"*), align 8
 constexpr auto &x = items[0].ti;
 
+// CHECK: @_ZN5Test11yE = constant %"class.std::type_info"* bitcast ({{.*}}* 
@_ZTIN5Test11BE to %"class.std::type_info"*), align 8
+constexpr auto &y = typeid(B{});
+
 }

Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL: 
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=166156&r1=166155&r2=166156&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Wed Oct 17 18:52:07 
2012
@@ -1408,3 +1408,14 @@
   static_assert(get(arr, 0) == 4, ""); // expected-error{{not an integral 
constant expression}} \
   // expected-note{{in call to 'get(arr, 0)'}}
 }
+
+namespace std { struct type_info; }
+
+namespace TypeId {
+  struct A { virtual ~A(); };
+  A f();
+  A &g();
+  constexpr auto &x = typeid(f());
+  constexpr auto &y = typeid(g()); // expected-error{{constant expression}} \
+  // expected-note{{typeid applied to expression of polymorphic type 
'TypeId::A' is not allowed in a constant expression}}
+}


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