Sema: Subst type default template args earlier

Summary:
We would not perform substitution at an appropriate point, allowing strange
results to appear. We would accepts things that we shouldn't or mangle things incorrectly.  Note that this hasn't fixed the other cases like
template-template parameters or non-type template parameters.

Reviewers: doug.gregor, rjmccall, rsmith

Reviewed By: rsmith

CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1507

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189540 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 4268aa24e368ce722a30fd8352ffe8ddf4caddca..426b13cfaf44a0e46ef9d65b6d671f3b7ca61a2f 100644 (file)
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -2976,22 +2976,25 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
   // If the argument type is dependent, instantiate it now based
   // on the previously-computed template arguments.
   if (ArgType->getType()->isDependentType()) {
-    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
-                                      Converted.data(), Converted.size());
-
-    MultiLevelTemplateArgumentList AllTemplateArgs
-      = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
-
     Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
                                      Template, Converted,
                                      SourceRange(TemplateLoc, RAngleLoc));
     if (Inst)
       return 0;
 
+    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                      Converted.data(), Converted.size());
+
+    // Only substitute for the innermost template argument list.
+    MultiLevelTemplateArgumentList TemplateArgLists;
+    TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
+    for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
+      TemplateArgLists.addOuterTemplateArguments(None);
+
     Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
-    ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs,
-                                Param->getDefaultArgumentLoc(),
-                                Param->getDeclName());
+    ArgType =
+        SemaRef.SubstType(ArgType, TemplateArgLists,
+                          Param->getDefaultArgumentLoc(), Param->getDeclName());
   }
 
   return ArgType;
@@ -3026,21 +3029,24 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
                              SourceLocation RAngleLoc,
                              NonTypeTemplateParmDecl *Param,
                         SmallVectorImpl<TemplateArgument> &Converted) {
-  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
-                                    Converted.data(), Converted.size());
-
-  MultiLevelTemplateArgumentList AllTemplateArgs
-    = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
-
   Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
                                    Template, Converted,
                                    SourceRange(TemplateLoc, RAngleLoc));
   if (Inst)
     return ExprError();
 
+  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                    Converted.data(), Converted.size());
+
+  // Only substitute for the innermost template argument list.
+  MultiLevelTemplateArgumentList TemplateArgLists;
+  TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
+  for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
+    TemplateArgLists.addOuterTemplateArguments(None);
+
   Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
   EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
-  return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs);
+  return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
 }
 
 /// \brief Substitute template arguments into the default template argument for
@@ -3076,32 +3082,35 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
                              TemplateTemplateParmDecl *Param,
                        SmallVectorImpl<TemplateArgument> &Converted,
                              NestedNameSpecifierLoc &QualifierLoc) {
-  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
-                                    Converted.data(), Converted.size());
-
-  MultiLevelTemplateArgumentList AllTemplateArgs
-    = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
-
-  Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
-                                   Template, Converted,
+  Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted,
                                    SourceRange(TemplateLoc, RAngleLoc));
   if (Inst)
     return TemplateName();
 
+  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                    Converted.data(), Converted.size());
+
+  // Only substitute for the innermost template argument list.
+  MultiLevelTemplateArgumentList TemplateArgLists;
+  TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
+  for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
+    TemplateArgLists.addOuterTemplateArguments(None);
+
   Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
-  // Substitute into the nested-name-specifier first, 
+  // Substitute into the nested-name-specifier first,
   QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
   if (QualifierLoc) {
-    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, 
-                                                       AllTemplateArgs);
+    QualifierLoc =
+        SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
     if (!QualifierLoc)
       return TemplateName();
   }
-  
-  return SemaRef.SubstTemplateName(QualifierLoc,
-                      Param->getDefaultArgument().getArgument().getAsTemplate(),
-                              Param->getDefaultArgument().getTemplateNameLoc(),
-                                   AllTemplateArgs);
+
+  return SemaRef.SubstTemplateName(
+             QualifierLoc,
+             Param->getDefaultArgument().getArgument().getAsTemplate(),
+             Param->getDefaultArgument().getTemplateNameLoc(),
+             TemplateArgLists);
 }
 
 /// \brief If the given template parameter has a default template

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index a797ae66b19b61f55b845321ebf6762d2cb5480a..5d6847fdf0ea98f2942d3edb275a4a3edb9db2db 100644 (file)
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1737,8 +1737,13 @@ Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
                                  D->isParameterPack());
   Inst->setAccess(AS_public);
 
-  if (D->hasDefaultArgument())
-    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false);
+  if (D->hasDefaultArgument()) {
+    TypeSourceInfo *InstantiatedDefaultArg =
+        SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
+                          D->getDefaultArgumentLoc(), D->getDeclName());
+    if (InstantiatedDefaultArg)
+      Inst->setDefaultArgument(InstantiatedDefaultArg, false);
+  }
 
   // Introduce this template parameter's instantiation into the instantiation
   // scope.
@@ -1888,7 +1893,11 @@ Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
   if (Invalid)
     Param->setInvalidDecl();
 
-  Param->setDefaultArgument(D->getDefaultArgument(), false);
+  if (D->hasDefaultArgument()) {
+    ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
+    if (!Value.isInvalid())
+      Param->setDefaultArgument(Value.get(), false);
+  }
 
   // Introduce this template parameter's instantiation into the instantiation
   // scope.
@@ -2011,7 +2020,21 @@ TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
                                              D->getPosition(),
                                              D->isParameterPack(),
                                              D->getIdentifier(), InstParams);
-  Param->setDefaultArgument(D->getDefaultArgument(), false);
+  if (D->hasDefaultArgument()) {
+    NestedNameSpecifierLoc QualifierLoc =
+        D->getDefaultArgument().getTemplateQualifierLoc();
+    QualifierLoc =
+        SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
+    TemplateName TName = SemaRef.SubstTemplateName(
+        QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
+        D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
+    if (!TName.isNull())
+      Param->setDefaultArgument(
+          TemplateArgumentLoc(TemplateArgument(TName),
+                              D->getDefaultArgument().getTemplateQualifierLoc(),
+                              D->getDefaultArgument().getTemplateNameLoc()),
+          false);
+  }
   Param->setAccess(AS_public);
 
   // Introduce this template parameter's instantiation into the instantiation

diff --git a/test/CodeGenCXX/mangle.cpp b/test/CodeGenCXX/mangle.cpp
index a9daa0df6194d14a55646930af7e57781bdd29dc..f03f499fe13fc23b94d9476b19a685417b248aea 100644 (file)
--- a/test/CodeGenCXX/mangle.cpp
+++ b/test/CodeGenCXX/mangle.cpp
@@ -910,3 +910,26 @@ namespace test40 {
   };
   void g() { f(); }
 }
+
+namespace test41 {
+  // CHECK: define linkonce_odr void @_ZN6test414funcINS_1XEEEvNS_3fooILi20ES1_EE
+  template <int i, class T> struct foo {
+    template <class T2 = T> friend void func(foo x) {}
+  };
+
+  struct X {};
+
+  void g() { func(foo<20, X>()); }
+}
+
+namespace test42 {
+  // CHECK: define linkonce_odr void @_ZN6test424funcINS_1XEEEvNS_3fooILi20ES1_EE
+  template <int i, template <class> class T> struct foo {
+    template <template <class> class T2 = T> friend void func(foo x) {}
+  };
+
+  template <class V> struct X {
+  };
+
+  void g() { func(foo<20, X>()); }
+}

diff --git a/test/SemaCXX/cxx1y-deduced-return-type.cpp b/test/SemaCXX/cxx1y-deduced-return-type.cpp
index 26d776f375dd3f63649ce3b029aada15628a6aff..9e779bf170aaf971f1276fd2011705ad23d1a15e 100644 (file)
--- a/test/SemaCXX/cxx1y-deduced-return-type.cpp
+++ b/test/SemaCXX/cxx1y-deduced-return-type.cpp
@@ -399,3 +399,12 @@ namespace CurrentInstantiation {
   template<typename T> auto U<T>::f() { return T(); }
   template int U<short>::g(); // ok
 }
+
+namespace WithDefaultArgs {
+  template<typename U> struct A {
+    template<typename T = U> friend auto f(A) { return []{}; }
+  };
+  template<typename T> void f();
+  using T = decltype(f(A<int>()));
+  using T = decltype(f<int>(A<int>()));
+}

diff --git a/test/SemaTemplate/default-arguments-cxx0x.cpp b/test/SemaTemplate/default-arguments-cxx0x.cpp
index 4c815f655875c93ad4903d63162d227baaa062dc..4cfd7a5843f01bd601db01a9788277456b3eb397 100644 (file)
--- a/test/SemaTemplate/default-arguments-cxx0x.cpp
+++ b/test/SemaTemplate/default-arguments-cxx0x.cpp
@@ -25,3 +25,34 @@ void g1() {
   float &fr = f1(15);
   int &ir = f1(HasValue());
 }
+
+namespace PR16689 {
+  template <typename T1, typename T2> class tuple {
+  public:
+      template <typename = T2>
+      constexpr tuple() {}
+  };
+  template <class X, class... Y> struct a : public X {
+    using X::X;
+  };
+  auto x = a<tuple<int, int> >();
+}
+
+namespace PR16975 {
+  template <typename...> struct is {
+    constexpr operator bool() const { return false; }
+  };
+
+  template <typename... Types>
+  struct bar {
+    template <typename T,
+              bool = is<Types...>()>
+    bar(T);
+  };
+
+  struct baz : public bar<> {
+    using bar::bar;
+  };
+
+  baz data{0};
+}

diff --git a/test/SemaTemplate/default-arguments.cpp b/test/SemaTemplate/default-arguments.cpp
index aca5c972adbc91cd369e1bd3ea6fbe22d9a13b16..439a30392118f7b3da7b76119776ca267c96ac5a 100644 (file)
--- a/test/SemaTemplate/default-arguments.cpp
+++ b/test/SemaTemplate/default-arguments.cpp
@@ -47,11 +47,13 @@ template<typename T> struct X1 { };
 
 template<typename T>
 struct X2 {
-  template<typename U = typename X1<T>::type> // expected-error{{no type named}}
-  struct Inner1 { };
+  template<typename U = typename X1<T>::type> // expected-error{{no type named 'type' in 'X1<int>'}} \
+                                              // expected-error{{no type named 'type' in 'X1<char>'}}
+  struct Inner1 { }; // expected-note{{template is declared here}}
   
-  template<T Value = X1<T>::value> // expected-error{{no member named 'value'}}
-  struct NonType1 { };
+  template<T Value = X1<T>::value> // expected-error{{no member named 'value' in 'X1<int>'}} \
+                                   // expected-error{{no member named 'value' in 'X1<char>'}}
+  struct NonType1 { }; // expected-note{{template is declared here}}
   
   template<T Value>
   struct Inner2 { };
@@ -67,17 +69,17 @@ struct X2 {
   };
 };
 
-X2<int> x2i;
+X2<int> x2i; // expected-note{{in instantiation of template class 'X2<int>' requested here}}
 X2<int>::Inner1<float> x2iif;
 
-X2<int>::Inner1<> x2bad; // expected-note{{instantiation of default argument}}
+X2<int>::Inner1<> x2bad; // expected-error{{too few template arguments for class template 'Inner1'}}
 
 X2<int>::NonType1<'a'> x2_nontype1;
-X2<int>::NonType1<> x2_nontype1_bad; // expected-note{{instantiation of default argument}}
+X2<int>::NonType1<> x2_nontype1_bad; // expected-error{{too few template arguments for class template 'NonType1'}}
 
 // Check multi-level substitution into template type arguments
 X2<int>::Inner3<float>::VeryInner<> vi;
-X2<char>::Inner3<int>::NonType2<> x2_deep_nontype;
+X2<char>::Inner3<int>::NonType2<> x2_deep_nontype; // expected-note{{in instantiation of template class 'X2<char>' requested here}}
 
 template<typename T, typename U>
 struct is_same { static const bool value = false; };
@@ -147,3 +149,13 @@ namespace PR16288 {
   template<typename T, typename U>
   void S<X>::f() {}
 }
+
+namespace DR1635 {
+  template <class T> struct X {
+    template <class U = typename T::type> static void f(int) {} // expected-error {{type 'int' cannot be used prior to '::' because it has no members}} \
+                                                                // expected-warning {{C++11}}
+    static void f(...) {}
+  };
+
+  int g() { X<int>::f(0); } // expected-note {{in instantiation of template class 'DR1635::X<int>' requested here}}
+}