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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@287999 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 91cdb67f30379a369d1b618539691b221570d805..dfbbf01a515c07738a5774bd81b65168b1b2090a 100644 (file)
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -4416,9 +4416,12 @@ static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
         // 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 &Self, TypeTrait UTT,
       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

diff --git a/test/SemaCXX/cxx11-crashes.cpp b/test/SemaCXX/cxx11-crashes.cpp
index 97c959454c354c651042b036b9e11e1b9b8a64c2..7c455eecd5fa3ff279a8401ca5c6ee0e4519247b 100644 (file)
--- a/test/SemaCXX/cxx11-crashes.cpp
+++ b/test/SemaCXX/cxx11-crashes.cpp
@@ -91,3 +91,15 @@ void test(int some_number) {  // expected-note {{'some_number' declared here}}
   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); }
+}