From: Richard Trieu <rtrieu@google.com>
Date: Sat, 7 Jul 2018 00:17:25 +0000 (+0000)
Subject: Check returned type is valid before using it.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2af72fe5e815083513b80862541e312b92ced5f0;p=clang

Check returned type is valid before using it.

Add a .isNull() check to returned QualType.  Fixes PR38077


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@336475 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index 61a82aa721..f2fad825c3 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -846,6 +846,9 @@ bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
   assert(DS.getTypeSpecType() == DeclSpec::TST_decltype);
 
   QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
+  if (T.isNull())
+    return true;
+
   if (!T->isDependentType() && !T->getAs<TagType>()) {
     Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class_or_namespace) 
       << T << getLangOpts().CPlusPlus;
diff --git a/test/SemaCXX/overloaded-name.cpp b/test/SemaCXX/overloaded-name.cpp
index 6da0354400..8f1dc2f59c 100644
--- a/test/SemaCXX/overloaded-name.cpp
+++ b/test/SemaCXX/overloaded-name.cpp
@@ -28,3 +28,11 @@ namespace rdar9623945 {
     }
   };
 }
+
+namespace PR38077 {
+  template <class T> void bar() {} // expected-note {{possible target for call}}
+
+  int run() {
+    decltype(bar)::does_not_exist; // expected-error {{reference to overloaded function could not be resolved; did you mean to call it?}}
+  }
+}