[c++1z] Implement N3994: a range-based for loop can declare a variable with super-terse notation

  for (x : range) { ... }

which is equivalent to

  for (auto &&x : range) { ... }


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211267 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 18 insertions, 0 deletions

diff --git a/include/clang/Basic/DiagnosticParseKinds.td b/include/clang/Basic/DiagnosticParseKinds.td
index b2da81e17d..874e0e2049 100644
--- a/include/clang/Basic/DiagnosticParseKinds.td
+++ b/include/clang/Basic/DiagnosticParseKinds.td
@@ -277,6 +277,13 @@ def ext_for_range : ExtWarn<
 def warn_cxx98_compat_for_range : Warning<
   "range-based for loop is incompatible with C++98">,
   InGroup<CXX98Compat>, DefaultIgnore;
+def ext_for_range_identifier : ExtWarn<
+  "range-based for loop with implicit deduced type is a C++1z extension">,
+  InGroup<CXX1z>;
+def warn_cxx1y_compat_for_range_identifier : Warning<
+  "range-based for loop with implicit deduced type is incompatible with "
+  "C++ standards before C++1z">,
+  InGroup<CXXPre1zCompat>, DefaultIgnore;
 def err_for_range_expected_decl : Error<
   "for range declaration must declare a variable">;
 def err_argument_required_after_attribute : Error<
diff --git a/include/clang/Parse/Parser.h b/include/clang/Parse/Parser.h
index 019660e184..2c76dce761 100644
--- a/include/clang/Parse/Parser.h
+++ b/include/clang/Parse/Parser.h
@@ -1827,6 +1827,9 @@ private:
     return isDeclarationSpecifier(true);
   }
 
+  /// \brief Determine whether this is a C++1z for-range-identifier.
+  bool isForRangeIdentifier();
+
   /// \brief Determine whether we are currently at the start of an Objective-C
   /// class message that appears to be missing the open bracket '['.
   bool isStartOfObjCClassMessageMissingOpenBracket();
@@ -2006,6 +2009,10 @@ private:
   // for example, attributes appertain to decl specifiers.
   void ProhibitCXX11Attributes(ParsedAttributesWithRange &attrs);
 
+  /// \brief Skip C++11 attributes and return the end location of the last one.
+  /// \returns SourceLocation() if there are no attributes.
+  SourceLocation SkipCXX11Attributes();
+
   /// \brief Diagnose and skip C++11 attributes that appear in syntactic
   /// locations where attributes are not allowed.
   void DiagnoseAndSkipCXX11Attributes();
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 86ab905dbb..872dbffb80 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -1622,6 +1622,10 @@ public:
   void ActOnUninitializedDecl(Decl *dcl, bool TypeMayContainAuto);
   void ActOnInitializerError(Decl *Dcl);
   void ActOnCXXForRangeDecl(Decl *D);
+  StmtResult ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
+                                        IdentifierInfo *Ident,
+                                        ParsedAttributes &Attrs,
+                                        SourceLocation AttrEnd);
   void SetDeclDeleted(Decl *dcl, SourceLocation DelLoc);
   void SetDeclDefaulted(Decl *dcl, SourceLocation DefaultLoc);
   void FinalizeDeclaration(Decl *D);