r368600 - [Sema] Require a complete type for __builtin_bit_cast operands

[Erik Pilkington via cfe-commits]

Author: epilk
Date: Mon Aug 12 11:31:27 2019
New Revision: 368600

URL: http://llvm.org/viewvc/llvm-project?rev=368600&view=rev
Log:
[Sema] Require a complete type for __builtin_bit_cast operands

Fixes llvm.org/PR42936

Modified:
    cfe/trunk/lib/Sema/SemaCast.cpp
    cfe/trunk/test/SemaCXX/builtin-bit-cast.cpp

Modified: cfe/trunk/lib/Sema/SemaCast.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCast.cpp?rev=368600&r1=368599&r2=368600&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaCast.cpp (original)
+++ cfe/trunk/lib/Sema/SemaCast.cpp Mon Aug 12 11:31:27 2019
@@ -2803,6 +2803,14 @@ void CastOperation::CheckBuiltinBitCast(
     SrcExpr = Self.CreateMaterializeTemporaryExpr(SrcType, SrcExpr.get(),
                                                   /*IsLValueReference=*/false);
 
+  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
+                               diag::err_typecheck_cast_to_incomplete) ||
+      Self.RequireCompleteType(OpRange.getBegin(), SrcType,
+                               diag::err_incomplete_type)) {
+    SrcExpr = ExprError();
+    return;
+  }
+
   CharUnits DestSize = Self.Context.getTypeSizeInChars(DestType);
   CharUnits SourceSize = Self.Context.getTypeSizeInChars(SrcType);
   if (DestSize != SourceSize) {

Modified: cfe/trunk/test/SemaCXX/builtin-bit-cast.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/builtin-bit-cast.cpp?rev=368600&r1=368599&r2=368600&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/builtin-bit-cast.cpp (original)
+++ cfe/trunk/test/SemaCXX/builtin-bit-cast.cpp Mon Aug 12 11:31:27 2019
@@ -37,3 +37,12 @@ constexpr unsigned long ul = __builtin_b
 
 // expected-error at +1 {{__builtin_bit_cast destination type must be trivially copyable}}
 constexpr long us = __builtin_bit_cast(unsigned long &, 0L);
+
+namespace PR42936 {
+template <class T> struct S { int m; };
+
+extern S<int> extern_decl;
+
+int x = __builtin_bit_cast(int, extern_decl);
+S<char> y = __builtin_bit_cast(S<char>, 0);
+}