2006-11-01 Douglas Gregor <doug.gregor@gmail.com>

	* c-common.c (flag_cpp0x): New.
	* c-common.h (flag_cpp0x): New.
	* c-cppbuiltin.c (c_cpp_builtins): If C++0x extensions are
	supported, define __GXX_EXPERIMENTAL_CPP0X__.
	* c-opts.c (set_std_cxx0x): New.
	(c_common_handle_option): Handle -std=c++0x, -std=gnu++0x.
	* c.opt (std=c++0x): Document.
	(std=gnu++0x): Ditto.
	* doc/cpp.texi: Document __GXX_EXPERIMENTAL_CPP0X__.
	* doc/invoke.texi: Document -std=c++0x, -std=gnu++0x.
	


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@118386 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 64 insertions, 1 deletions

diff --git a/gcc/c-common.c b/gcc/c-common.c
index a901aba2f50..47cda1b6413 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -401,6 +401,11 @@ int flag_access_control = 1;
 
 int flag_check_new;
 
+/* Nonzero if we want to allow the use of experimental features that
+   are likely to become part of C++0x. */
+
+int flag_cpp0x = 0;
+
 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
    initialization variables.
    0: Old rules, set by -fno-for-scope.
diff --git a/gcc/c-common.h b/gcc/c-common.h
index f6f36e0114f..40d8b963719 100644
--- a/gcc/c-common.h
+++ b/gcc/c-common.h
@@ -521,6 +521,11 @@ extern int flag_access_control;
 
 extern int flag_check_new;
 
+/* Nonzero if we want to allow the use of experimental features that
+   are likely to become part of C++0x. */
+
+extern int flag_cpp0x;
+
 /* Nonzero if we want the new ISO rules for pushing a new scope for `for'
    initialization variables.
    0: Old rules, set by -fno-for-scope.
diff --git a/gcc/c-cppbuiltin.c b/gcc/c-cppbuiltin.c
index c6e5c6d34f8..dc0c3438dca 100644
--- a/gcc/c-cppbuiltin.c
+++ b/gcc/c-cppbuiltin.c
@@ -409,6 +409,8 @@ c_cpp_builtins (cpp_reader *pfile)
 	cpp_define (pfile, "__GXX_WEAK__=0");
       if (warn_deprecated)
 	cpp_define (pfile, "__DEPRECATED");
+      if (flag_cpp0x)
+        cpp_define (pfile, "__GXX_EXPERIMENTAL_CPP0X__");
     }
   /* Note that we define this for C as well, so that we know if
      __attribute__((cleanup)) will interface with EH.  */
diff --git a/gcc/c-opts.c b/gcc/c-opts.c
index b74ce773088..1abb374c476 100644
--- a/gcc/c-opts.c
+++ b/gcc/c-opts.c
@@ -109,6 +109,7 @@ static size_t include_cursor;
 static void set_Wimplicit (int);
 static void handle_OPT_d (const char *);
 static void set_std_cxx98 (int);
+static void set_std_cxx0x (int);
 static void set_std_c89 (int, int);
 static void set_std_c99 (int);
 static void check_deps_environment_vars (void);
@@ -789,7 +790,7 @@ c_common_handle_option (size_t scode, const char *arg, int value)
     case OPT_fuse_cxa_atexit:
       flag_use_cxa_atexit = value;
       break;
-      
+
     case OPT_fuse_cxa_get_exception_ptr:
       flag_use_cxa_get_exception_ptr = value;
       break;
@@ -913,6 +914,12 @@ c_common_handle_option (size_t scode, const char *arg, int value)
 	set_std_cxx98 (code == OPT_std_c__98 /* ISO */);
       break;
 
+    case OPT_std_c__0x:
+    case OPT_std_gnu__0x:
+      if (!preprocessing_asm_p)
+	set_std_cxx0x (code == OPT_std_c__0x /* ISO */);
+      break;
+
     case OPT_std_c89:
     case OPT_std_iso9899_1990:
     case OPT_std_iso9899_199409:
@@ -1509,6 +1516,17 @@ set_std_cxx98 (int iso)
   flag_iso = iso;
 }
 
+/* Set the C++ 0x working draft "standard" (without GNU extensions if ISO).  */
+static void
+set_std_cxx0x (int iso)
+{
+  cpp_set_lang (parse_in, iso ? CLK_CXX0X: CLK_GNUCXX0X);
+  flag_no_gnu_keywords = iso;
+  flag_no_nonansi_builtin = iso;
+  flag_iso = iso;
+  flag_cpp0x = 1;
+}
+
 /* Handle setting implicit to ON.  */
 static void
 set_Wimplicit (int on)
diff --git a/gcc/c.opt b/gcc/c.opt
index 0aa0a3ad30c..01cb779dc31 100644
--- a/gcc/c.opt
+++ b/gcc/c.opt
@@ -842,6 +842,13 @@ std=c++98
 C++ ObjC++
 Conform to the ISO 1998 C++ standard
 
+std=c++0x
+C++ ObjC++
+Conform to the ISO 1998 C++ standard, with extensions that are likely to
+become a part of the upcoming ISO C++ standard, dubbed C++0x. Note that the
+extensions enabled by this mode are experimental and may be removed in
+future releases of GCC.
+
 std=c89
 C ObjC
 Conform to the ISO 1990 C standard
@@ -858,6 +865,13 @@ std=gnu++98
 C++ ObjC++
 Conform to the ISO 1998 C++ standard with GNU extensions
 
+std=gnu++0x
+C++ ObjC++
+Conform to the ISO 1998 C++ standard, with GNU extensions and
+extensions that are likely to become a part of the upcoming ISO C++
+standard, dubbed C++0x. Note that the extensions enabled by this mode
+are experimental and may be removed in future releases of GCC.
+
 std=gnu89
 C ObjC
 Conform to the ISO 1990 C standard with GNU extensions
diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi
index 13b92f306e5..5a7513667f4 100644
--- a/gcc/doc/cpp.texi
+++ b/gcc/doc/cpp.texi
@@ -2094,6 +2094,13 @@ This macro is defined, with value 1, if the compiler uses the old
 mechanism based on @code{setjmp} and @code{longjmp} for exception
 handling.
 
+@item __GXX_EXPERIMENTAL_CPP0X__
+This macro is defined when compiling a C++ source file with the option
+@option{-std=c++0x} or @option{-std=gnu++0x}. It indicates that some
+features likely to be included in C++0x are available. Note that these
+features are experimental, and may change or be removed in future
+versions of GCC.
+
 @item __GXX_WEAK__
 This macro is defined when compiling a C++ source file.  It has the
 value 1 if the compiler will use weak symbols, COMDAT sections, or
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a77f9f2dc43..c62c02c31cd 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1199,6 +1199,18 @@ The 1998 ISO C++ standard plus amendments.
 @item gnu++98
 The same as @option{-std=c++98} plus GNU extensions.  This is the
 default for C++ code.
+
+@item c++0x
+The working draft of the upcoming ISO C++0x standard. This option
+enables experimental features that are likely to be included in
+C++0x. The working draft is constantly changing, and any feature that is
+enabled by this flag may be removed from future versions of GCC if it is
+not part of the C++0x standard.
+
+@item gnu++0x
+The same as @option{-std=c++0x} plus GNU extensions. As with
+@option{-std=c++0x}, this option enables experimental features that may
+be removed in future versions of GCC.
 @end table
 
 Even when this option is not specified, you can still use some of the