[cfe-commits] r99652 - in /cfe/trunk: lib/Sema/SemaExprCXX.cpp test/SemaCXX/conditional-expr.cpp

[Douglas Gregor]

Author: dgregor
Date: Fri Mar 26 15:59:55 2010
New Revision: 99652

URL: http://llvm.org/viewvc/llvm-project?rev=99652&view=rev
Log:
When trying to determine whether one operand of a conditional
expression can be converted to the type of another, only apply the
lvalue-to-rvalue conversion to the type of the expression we're
converting, *not* the array-to-pointer or function-to-pointer
conversions. Fixes PR6595.

Modified:
    cfe/trunk/lib/Sema/SemaExprCXX.cpp
    cfe/trunk/test/SemaCXX/conditional-expr.cpp

Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=99652&r1=99651&r2=99652&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Fri Mar 26 15:59:55 2010
@@ -1934,7 +1934,8 @@
   //   can be converted to match an operand expression E2 of type T2 is defined
   //   as follows:
   //   -- If E2 is an lvalue:
-  if (To->isLvalue(Self.Context) == Expr::LV_Valid) {
+  bool ToIsLvalue = (To->isLvalue(Self.Context) == Expr::LV_Valid);
+  if (ToIsLvalue) {
     //   E1 can be converted to match E2 if E1 can be implicitly converted to
     //   type "lvalue reference to T2", subject to the constraint that in the
     //   conversion the reference must bind directly to E1.
@@ -1985,12 +1986,13 @@
   
   //     -- Otherwise: E1 can be converted to match E2 if E1 can be
   //        implicitly converted to the type that expression E2 would have
-  //        if E2 were converted to an rvalue.
-  // First find the decayed type.
-  if (TTy->isFunctionType())
-    TTy = Self.Context.getPointerType(TTy);
-  else if (TTy->isArrayType())
-    TTy = Self.Context.getArrayDecayedType(TTy);
+  //        if E2 were converted to an rvalue (or the type it has, if E2 is 
+  //        an rvalue).
+  //
+  // This actually refers very narrowly to the lvalue-to-rvalue conversion, not
+  // to the array-to-pointer or function-to-pointer conversions.
+  if (!TTy->getAs<TagType>())
+    TTy = TTy.getUnqualifiedType();
   
   InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
   InitializationSequence InitSeq(Self, Entity, Kind, &From, 1);

Modified: cfe/trunk/test/SemaCXX/conditional-expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/conditional-expr.cpp?rev=99652&r1=99651&r2=99652&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/conditional-expr.cpp (original)
+++ cfe/trunk/test/SemaCXX/conditional-expr.cpp Fri Mar 26 15:59:55 2010
@@ -198,3 +198,18 @@
   // *must* create a separate temporary copy of class objects. This can only
   // be properly tested at runtime, though.
 }
+
+namespace PR6595 {
+  struct String {
+    String(const char *);
+    operator const char*() const;
+  };
+
+  void f(bool Cond, String S) {
+    (void)(Cond? S : "");
+    (void)(Cond? "" : S);
+    const char a[1] = {'a'};
+    (void)(Cond? S : a);
+    (void)(Cond? a : S);
+  }
+}