r287999 - Adjust type-trait evaluation to properly handle Using(Shadow)Decls

[Hal Finkel via cfe-commits]

Author: hfinkel
Date: Sun Nov 27 10:26:14 2016
New Revision: 287999

URL: http://llvm.org/viewvc/llvm-project?rev=287999&view=rev
Log:
Adjust type-trait evaluation to properly handle Using(Shadow)Decls

Since r274049, for an inheriting constructor declaration, the name of the using
declaration (and using shadow declaration comes from the using declaration) is
the name of a derived class, not the base class (line 8225-8232 of
lib/Sema/SemaDeclCXX.cpp in https://reviews.llvm.org/rL274049). Because of
this, name-based lookup performed inside Sema::LookupConstructors returns not
only CXXConstructorDecls but also Using(Shadow)Decls, which results assertion
failure reported in PR29087.

Patch by Taewook Oh, thanks!

Differential Revision: https://reviews.llvm.org/D23765

Modified:
    cfe/trunk/lib/Sema/SemaExprCXX.cpp
    cfe/trunk/test/SemaCXX/cxx11-crashes.cpp

Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=287999&r1=287998&r2=287999&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Sun Nov 27 10:26:14 2016
@@ -4416,9 +4416,12 @@ static bool EvaluateUnaryTypeTrait(Sema
         // A template constructor is never a copy constructor.
         // FIXME: However, it may actually be selected at the actual overload
         // resolution point.
-        if (isa<FunctionTemplateDecl>(ND))
+        if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
           continue;
-        const CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(ND);
+        // UsingDecl itself is not a constructor
+        if (isa<UsingDecl>(ND))
+          continue;
+        auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
         if (Constructor->isCopyConstructor(FoundTQs)) {
           FoundConstructor = true;
           const FunctionProtoType *CPT
@@ -4452,9 +4455,12 @@ static bool EvaluateUnaryTypeTrait(Sema
       bool FoundConstructor = false;
       for (const auto *ND : Self.LookupConstructors(RD)) {
         // FIXME: In C++0x, a constructor template can be a default constructor.
-        if (isa<FunctionTemplateDecl>(ND))
+        if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl()))
+          continue;
+        // UsingDecl itself is not a constructor
+        if (isa<UsingDecl>(ND))
           continue;
-        const CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(ND);
+        auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl());
         if (Constructor->isDefaultConstructor()) {
           FoundConstructor = true;
           const FunctionProtoType *CPT

Modified: cfe/trunk/test/SemaCXX/cxx11-crashes.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx11-crashes.cpp?rev=287999&r1=287998&r2=287999&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx11-crashes.cpp (original)
+++ cfe/trunk/test/SemaCXX/cxx11-crashes.cpp Sun Nov 27 10:26:14 2016
@@ -91,3 +91,15 @@ void test(int some_number) {  // expecte
   Foo(lambda);
 }
 }
+
+namespace pr29091 {
+  struct X{ X(const X &x); };
+  struct Y: X { using X::X; };
+  bool foo() { return __has_nothrow_constructor(Y); }
+  bool bar() { return __has_nothrow_copy(Y); }
+
+  struct A { template <typename T> A(); };
+  struct B : A { using A::A; };
+  bool baz() { return __has_nothrow_constructor(B); }
+  bool qux() { return __has_nothrow_copy(B); }
+}