r352307 - Remove Expr sugar decorating the CXXUuidofExpr node.

[Bill Wendling via cfe-commits]

Author: void
Date: Sat Jan 26 23:24:03 2019
New Revision: 352307

URL: http://llvm.org/viewvc/llvm-project?rev=352307&view=rev
Log:
Remove Expr sugar decorating the CXXUuidofExpr node.

Summary: Sugar, like ConstantExpr, causes an infinite expansion of the template object.

Reviewers: rsmith, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: riccibruno, aaron.ballman, cfe-commits, tzik, rnk

Differential Revision: https://reviews.llvm.org/D57114

Added:
    cfe/trunk/test/SemaCXX/PR40395.cpp
Modified:
    cfe/trunk/lib/Sema/SemaTemplate.cpp

Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=352307&r1=352306&r2=352307&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Sat Jan 26 23:24:03 2019
@@ -6308,7 +6308,7 @@ ExprResult Sema::CheckTemplateArgument(N
       // -- a predefined __func__ variable
       if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
         if (isa<CXXUuidofExpr>(E)) {
-          Converted = TemplateArgument(ArgResult.get());
+          Converted = TemplateArgument(ArgResult.get()->IgnoreImpCasts());
           break;
         }
         Diag(Arg->getBeginLoc(), diag::err_template_arg_not_decl_ref)

Added: cfe/trunk/test/SemaCXX/PR40395.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/PR40395.cpp?rev=352307&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/PR40395.cpp (added)
+++ cfe/trunk/test/SemaCXX/PR40395.cpp Sat Jan 26 23:24:03 2019
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -std=c++17 -fms-extensions -triple=x86_64-pc-win32 -verify %s
+// expected-no-diagnostics
+
+// PR40395 - ConstantExpr shouldn't cause the template object to infinitely
+// expand.
+struct _GUID {};
+struct __declspec(uuid("{AAAAAAAA-AAAA-AAAA-AAAA-AAAAAAAAAAAA}")) B {};
+
+template <const _GUID* piid>
+struct A {
+  virtual void baz() { A<piid>(); }
+};
+
+void f() {
+  A<&__uuidof(B)>();
+}