[C++1z] Implement N4051: 'typename' is permitted instead of 'class' when declaring...

llvm-svn: 211031

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 2c1cf0ff4b4f8fe0d5d4ee501ac73fd1b3060468..6a9425e8947e010c0d79ec6e740a7434fcabec6a 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -121,6 +121,9 @@ def FormatZeroLength : DiagGroup<"format-zero-length">;
 def CXXPre1yCompat : DiagGroup<"c++98-c++11-compat">;
 def CXXPre1yCompatPedantic : DiagGroup<"c++98-c++11-compat-pedantic",
                                        [CXXPre1yCompat]>;
+def CXXPre1zCompat : DiagGroup<"c++98-c++11-c++14-compat">;
+def CXXPre1zCompatPedantic : DiagGroup<"c++98-c++11-c++14-compat-pedantic",
+                                       [CXXPre1zCompat]>;
 
 def CXX98CompatBindToTemporaryCopy :
   DiagGroup<"c++98-compat-bind-to-temporary-copy">;
@@ -133,11 +136,13 @@ def CXX98Compat : DiagGroup<"c++98-compat",
                             [CXX98CompatBindToTemporaryCopy,
                              CXX98CompatLocalTypeTemplateArgs,
                              CXX98CompatUnnamedTypeTemplateArgs,
-                             CXXPre1yCompat]>;
+                             CXXPre1yCompat,
+                             CXXPre1zCompat]>;
 // Warnings for C++11 features which are Extensions in C++98 mode.
 def CXX98CompatPedantic : DiagGroup<"c++98-compat-pedantic",
                                     [CXX98Compat,
-                                     CXXPre1yCompatPedantic]>;
+                                     CXXPre1yCompatPedantic,
+                                     CXXPre1zCompatPedantic]>;
 
 def CXX11Narrowing : DiagGroup<"c++11-narrowing">;
 
@@ -157,10 +162,16 @@ def CXX11Compat : DiagGroup<"c++11-compat",
                             [CXX11Narrowing,
                              CXX11CompatReservedUserDefinedLiteral,
                              CXX11CompatDeprecatedWritableStr,
-                             CXXPre1yCompat]>;
+                             CXXPre1yCompat,
+                             CXXPre1zCompat]>;
 def : DiagGroup<"c++0x-compat", [CXX11Compat]>;
 def CXX11CompatPedantic : DiagGroup<"c++11-compat-pedantic",
-                                    [CXXPre1yCompatPedantic]>;
+                                    [CXXPre1yCompatPedantic,
+                                     CXXPre1zCompatPedantic]>;
+
+def CXX14Compat : DiagGroup<"c++14-compat", [CXXPre1zCompat]>;
+def CXX14CompatPedantic : DiagGroup<"c++14-compat-pedantic",
+                                    [CXXPre1zCompatPedantic]>;
 
 def : DiagGroup<"effc++">;
 def DivZero : DiagGroup<"division-by-zero">;
@@ -620,6 +631,10 @@ def CXX11 : DiagGroup<"c++11-extensions", [CXX11ExtraSemi, CXX11LongLong]>;
 // earlier C++ versions.
 def CXX1y : DiagGroup<"c++1y-extensions">;
 
+// A warning group for warnings about using C++1z features as extensions in
+// earlier C++ versions.
+def CXX1z : DiagGroup<"c++1z-extensions">;
+
 def : DiagGroup<"c++0x-extensions", [CXX11]>;
 def DelegatingCtorCycles :
   DiagGroup<"delegating-ctor-cycles">;

diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
index 392c9a7a1a4c02853ef3df1955b70b5691008b95..e874c8d9a705dac5123f39b30d232880a9b2c7e8 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -566,6 +566,13 @@ def err_expected_comma_greater : Error<
   "expected ',' or '>' in template-parameter-list">;
 def err_class_on_template_template_param : Error<
   "template template parameter requires 'class' after the parameter list">;
+def ext_template_template_param_typename : ExtWarn<
+  "template template parameter using 'typename' is a C++1z extension">,
+  InGroup<CXX1z>;
+def warn_cxx1y_compat_template_template_param_typename : Warning<
+  "template template parameter using 'typename' is "
+  "incompatible with C++ standards before C++1z">,
+  InGroup<CXXPre1zCompat>, DefaultIgnore;
 def err_template_spec_syntax_non_template : Error<
   "identifier followed by '<' indicates a class template specialization but "
   "%0 %select{does not refer to a template|refers to a function template|"

diff --git a/clang/lib/Parse/ParseTemplate.cpp b/clang/lib/Parse/ParseTemplate.cpp
index cecc531690e1d84d4727df6918ad388061b1d916..6551fe25da9f49b8f4e9898e1e19e676035cc2c4 100644 (file)
--- a/clang/lib/Parse/ParseTemplate.cpp
+++ b/clang/lib/Parse/ParseTemplate.cpp
@@ -519,10 +519,13 @@ Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
 /// template parameters.
 ///
 ///       type-parameter:    [C++ temp.param]
-///         'template' '<' template-parameter-list '>' 'class' 
+///         'template' '<' template-parameter-list '>' type-parameter-key
 ///                  ...[opt] identifier[opt]
-///         'template' '<' template-parameter-list '>' 'class' identifier[opt] 
-///                  = id-expression
+///         'template' '<' template-parameter-list '>' type-parameter-key
+///                  identifier[opt] = id-expression
+///       type-parameter-key:
+///         'class'
+///         'typename'       [C++1z]
 Decl *
 Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
   assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
@@ -539,20 +542,29 @@ Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
     }
   }
 
+  // Provide an ExtWarn if the C++1z feature of using 'typename' here is used.
   // Generate a meaningful error if the user forgot to put class before the
   // identifier, comma, or greater. Provide a fixit if the identifier, comma,
-  // or greater appear immediately or after 'typename' or 'struct'. In the
-  // latter case, replace the keyword with 'class'.
+  // or greater appear immediately or after 'struct'. In the latter case,
+  // replace the keyword with 'class'.
   if (!TryConsumeToken(tok::kw_class)) {
     bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct);
-    const Token& Next = Replace ? NextToken() : Tok;
-    if (Next.is(tok::identifier) || Next.is(tok::comma) ||
-        Next.is(tok::greater) || Next.is(tok::greatergreater) ||
-        Next.is(tok::ellipsis))
+    const Token &Next = Tok.is(tok::kw_struct) ? NextToken() : Tok;
+    if (Tok.is(tok::kw_typename)) {
+      Diag(Tok.getLocation(),
+           getLangOpts().CPlusPlus1z
+               ? diag::warn_cxx1y_compat_template_template_param_typename
+               : diag::ext_template_template_param_typename)
+        << (!getLangOpts().CPlusPlus1z
+                ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
+                : FixItHint());
+    } else if (Next.is(tok::identifier) || Next.is(tok::comma) ||
+               Next.is(tok::greater) || Next.is(tok::greatergreater) ||
+               Next.is(tok::ellipsis)) {
       Diag(Tok.getLocation(), diag::err_class_on_template_template_param)
         << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class")
                     : FixItHint::CreateInsertion(Tok.getLocation(), "class "));
-    else
+    } else
       Diag(Tok.getLocation(), diag::err_class_on_template_template_param);
 
     if (Replace)

diff --git a/clang/test/FixIt/fixit.cpp b/clang/test/FixIt/fixit.cpp
index 6a8e7d1e8494a9dab99899c41c66fde93666c3fb..f264938565605db7e956c003a51853ecf3f9aa1e 100644 (file)
--- a/clang/test/FixIt/fixit.cpp
+++ b/clang/test/FixIt/fixit.cpp
@@ -204,7 +204,7 @@ template<class T> typedef Mystery<T>::type getMysteriousThing() { // \
 }
 
 template<template<typename> Foo, // expected-error {{template template parameter requires 'class' after the parameter list}}
-         template<typename> typename Bar, // expected-error {{template template parameter requires 'class' after the parameter list}}
+         template<typename> typename Bar, // expected-warning {{template template parameter using 'typename' is a C++1z extension}}
          template<typename> struct Baz> // expected-error {{template template parameter requires 'class' after the parameter list}}
 void func();
 

diff --git a/clang/test/Parser/cxx-template-decl.cpp b/clang/test/Parser/cxx-template-decl.cpp
index 87429001223acd29d75751d7c7cbf720d773e830..8b2b12037b3c6abb49e243ce8f4e4790198421bf 100644 (file)
--- a/clang/test/Parser/cxx-template-decl.cpp
+++ b/clang/test/Parser/cxx-template-decl.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 // RUN: %clang_cc1 -fsyntax-only -verify %s -fdelayed-template-parsing -DDELAYED_TEMPLATE_PARSING
+// RUN: %clang_cc1 -fsyntax-only -verify -std=gnu++1z %s
 
 
 
@@ -24,6 +25,11 @@ template <template X> struct Err1; // expected-error {{expected '<' after 'templ
 template <template <typename> > struct Err2;       // expected-error {{template template parameter requires 'class' after the parameter list}}
 template <template <typename> Foo> struct Err3;    // expected-error {{template template parameter requires 'class' after the parameter list}}
 
+template <template <typename> typename Foo> struct Cxx1z;
+#if __cplusplus <= 201402L
+// expected-warning@-2 {{extension}}
+#endif
+
 // Template function declarations
 template <typename T> void foo();
 template <typename T, typename U> void foo();