Add new language mode flags for C17.

This adds -std=c17, -std=gnu17, and -std=iso9899:2017 as language mode flags for C17 and updates the value of __STDC_VERSION__ to the value based on the C17 FDIS. Given that this ballot cannot succeed until 2018, it is expected that we (and GCC) will add c18 flags as aliases once the ballot passes.

llvm-svn: 320089

clang/docs/ReleaseNotes.rst

@@ -121,6 +121,12 @@ New Compiler Flags
   number of attributes are supported outside of C++ mode. See the Clang
   attribute documentation for more information about which attributes are
   supported for each syntax.
+
+- Added the ``-std=c17``, ``-std=gnu17``, and ``-std=iso9899:2017`` language
+  mode flags for compatibility with GCC. This enables support for the next
+  version of the C standard, expected to be published by ISO in 2018. The only
+  difference between the ``-std=c17`` and ``-std=c11`` language modes is the
+  value of the ``__STDC_VERSION__`` macro, as C17 is a bug fix release.
 
 Deprecated Compiler Flags
 -------------------------

clang/include/clang/Frontend/LangStandard.h

@@ -1,110 +1,114 @@
-//===--- LangStandard.h -----------------------------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_CLANG_FRONTEND_LANGSTANDARD_H
-#define LLVM_CLANG_FRONTEND_LANGSTANDARD_H
-
-#include "clang/Basic/LLVM.h"
-#include "clang/Frontend/FrontendOptions.h"
-#include "llvm/ADT/StringRef.h"
-
-namespace clang {
-
-namespace frontend {
-
-enum LangFeatures {
-  LineComment = (1 << 0),
-  C99 = (1 << 1),
-  C11 = (1 << 2),
-  CPlusPlus = (1 << 3),
-  CPlusPlus11 = (1 << 4),
-  CPlusPlus14 = (1 << 5),
-  CPlusPlus17 = (1 << 6),
-  CPlusPlus2a = (1 << 7),
-  Digraphs = (1 << 8),
-  GNUMode = (1 << 9),
-  HexFloat = (1 << 10),
-  ImplicitInt = (1 << 11),
-  OpenCL = (1 << 12)
-};
-
-}
-
-/// LangStandard - Information about the properties of a particular language
-/// standard.
-struct LangStandard {
-  enum Kind {
-#define LANGSTANDARD(id, name, lang, desc, features) \
-    lang_##id,
-#include "clang/Frontend/LangStandards.def"
-    lang_unspecified
-  };
-
-  const char *ShortName;
-  const char *Description;
-  unsigned Flags;
-  InputKind::Language Language;
-
-public:
-  /// getName - Get the name of this standard.
-  const char *getName() const { return ShortName; }
-
-  /// getDescription - Get the description of this standard.
-  const char *getDescription() const { return Description; }
-
-  /// Get the language that this standard describes.
-  InputKind::Language getLanguage() const { return Language; }
-
-  /// Language supports '//' comments.
-  bool hasLineComments() const { return Flags & frontend::LineComment; }
-
-  /// isC99 - Language is a superset of C99.
-  bool isC99() const { return Flags & frontend::C99; }
-
-  /// isC11 - Language is a superset of C11.
-  bool isC11() const { return Flags & frontend::C11; }
-
-  /// isCPlusPlus - Language is a C++ variant.
-  bool isCPlusPlus() const { return Flags & frontend::CPlusPlus; }
-
-  /// isCPlusPlus11 - Language is a C++11 variant (or later).
-  bool isCPlusPlus11() const { return Flags & frontend::CPlusPlus11; }
-
-  /// isCPlusPlus14 - Language is a C++14 variant (or later).
-  bool isCPlusPlus14() const { return Flags & frontend::CPlusPlus14; }
-
-  /// isCPlusPlus17 - Language is a C++17 variant (or later).
-  bool isCPlusPlus17() const { return Flags & frontend::CPlusPlus17; }
-
-  /// isCPlusPlus2a - Language is a post-C++17 variant (or later).
-  bool isCPlusPlus2a() const { return Flags & frontend::CPlusPlus2a; }
-
-
-  /// hasDigraphs - Language supports digraphs.
-  bool hasDigraphs() const { return Flags & frontend::Digraphs; }
-
-  /// isGNUMode - Language includes GNU extensions.
-  bool isGNUMode() const { return Flags & frontend::GNUMode; }
-
-  /// hasHexFloats - Language supports hexadecimal float constants.
-  bool hasHexFloats() const { return Flags & frontend::HexFloat; }
-
-  /// hasImplicitInt - Language allows variables to be typed as int implicitly.
-  bool hasImplicitInt() const { return Flags & frontend::ImplicitInt; }
-
-  /// isOpenCL - Language is a OpenCL variant.
-  bool isOpenCL() const { return Flags & frontend::OpenCL; }
-
-  static const LangStandard &getLangStandardForKind(Kind K);
-  static const LangStandard *getLangStandardForName(StringRef Name);
-};
-
-}  // end namespace clang
-
-#endif
+//===--- LangStandard.h -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_FRONTEND_LANGSTANDARD_H
+#define LLVM_CLANG_FRONTEND_LANGSTANDARD_H
+
+#include "clang/Basic/LLVM.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "llvm/ADT/StringRef.h"
+
+namespace clang {
+
+namespace frontend {
+
+enum LangFeatures {
+  LineComment = (1 << 0),
+  C99 = (1 << 1),
+  C11 = (1 << 2),
+  C17 = (1 << 3),
+  CPlusPlus = (1 << 4),
+  CPlusPlus11 = (1 << 5),
+  CPlusPlus14 = (1 << 6),
+  CPlusPlus17 = (1 << 7),
+  CPlusPlus2a = (1 << 8),
+  Digraphs = (1 << 9),
+  GNUMode = (1 << 10),
+  HexFloat = (1 << 11),
+  ImplicitInt = (1 << 12),
+  OpenCL = (1 << 13)
+};
+
+}
+
+/// LangStandard - Information about the properties of a particular language
+/// standard.
+struct LangStandard {
+  enum Kind {
+#define LANGSTANDARD(id, name, lang, desc, features) \
+    lang_##id,
+#include "clang/Frontend/LangStandards.def"
+    lang_unspecified
+  };
+
+  const char *ShortName;
+  const char *Description;
+  unsigned Flags;
+  InputKind::Language Language;
+
+public:
+  /// getName - Get the name of this standard.
+  const char *getName() const { return ShortName; }
+
+  /// getDescription - Get the description of this standard.
+  const char *getDescription() const { return Description; }
+
+  /// Get the language that this standard describes.
+  InputKind::Language getLanguage() const { return Language; }
+
+  /// Language supports '//' comments.
+  bool hasLineComments() const { return Flags & frontend::LineComment; }
+
+  /// isC99 - Language is a superset of C99.
+  bool isC99() const { return Flags & frontend::C99; }
+
+  /// isC11 - Language is a superset of C11.
+  bool isC11() const { return Flags & frontend::C11; }
+
+  /// isC17 - Language is a superset of C17.
+  bool isC17() const { return Flags & frontend::C17; }
+
+  /// isCPlusPlus - Language is a C++ variant.
+  bool isCPlusPlus() const { return Flags & frontend::CPlusPlus; }
+
+  /// isCPlusPlus11 - Language is a C++11 variant (or later).
+  bool isCPlusPlus11() const { return Flags & frontend::CPlusPlus11; }
+
+  /// isCPlusPlus14 - Language is a C++14 variant (or later).
+  bool isCPlusPlus14() const { return Flags & frontend::CPlusPlus14; }
+
+  /// isCPlusPlus17 - Language is a C++17 variant (or later).
+  bool isCPlusPlus17() const { return Flags & frontend::CPlusPlus17; }
+
+  /// isCPlusPlus2a - Language is a post-C++17 variant (or later).
+  bool isCPlusPlus2a() const { return Flags & frontend::CPlusPlus2a; }
+
+
+  /// hasDigraphs - Language supports digraphs.
+  bool hasDigraphs() const { return Flags & frontend::Digraphs; }
+
+  /// isGNUMode - Language includes GNU extensions.
+  bool isGNUMode() const { return Flags & frontend::GNUMode; }
+
+  /// hasHexFloats - Language supports hexadecimal float constants.
+  bool hasHexFloats() const { return Flags & frontend::HexFloat; }
+
+  /// hasImplicitInt - Language allows variables to be typed as int implicitly.
+  bool hasImplicitInt() const { return Flags & frontend::ImplicitInt; }
+
+  /// isOpenCL - Language is a OpenCL variant.
+  bool isOpenCL() const { return Flags & frontend::OpenCL; }
+
+  static const LangStandard &getLangStandardForKind(Kind K);
+  static const LangStandard *getLangStandardForName(StringRef Name);
+};
+
+}  // end namespace clang
+
+#endif