c++: support C++11 attributes in C++98

I don't see any reason why we can't allow the [[]] attribute syntax in C++98
mode with a pedwarn just like many other C++11 features.  In fact, we
already do support it in some places in the grammar, but not in places that
check cp_nth_tokens_can_be_std_attribute_p.

Let's also follow the C front-end's lead in only warning about them when
-pedantic.

It still isn't necessary for this function to guard against Objective-C
message passing syntax; we handle that with tentative parsing in
cp_parser_statement, and we don't call this function in that context anyway.

gcc/cp/ChangeLog:

	* parser.cc (cp_nth_tokens_can_be_std_attribute_p): Don't check
	cxx_dialect.
	* error.cc (maybe_warn_cpp0x): Only complain about C++11 attributes
	if pedantic.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/gen-attrs-1.C: Also run in C++98 mode.
	* g++.dg/cpp0x/gen-attrs-11.C: Likewise.
	* g++.dg/cpp0x/gen-attrs-13.C: Likewise.
	* g++.dg/cpp0x/gen-attrs-15.C: Likewise.
	* g++.dg/cpp0x/gen-attrs-75.C: Don't expect C++98 warning after
	__extension__.

diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc
index 57cd76caf4903df71079683a29092bc08e43897f..4a9e9aa3cdcbe0381fa73217828c175dd199c1e7 100644 (file)
--- a/gcc/cp/error.cc
+++ b/gcc/cp/error.cc
@@ -4735,9 +4735,10 @@ maybe_warn_cpp0x (cpp0x_warn_str str, location_t loc/*=input_location*/)
                 "only available with %<-std=c++11%> or %<-std=gnu++11%>");
         break;
       case CPP0X_ATTRIBUTES:
-       pedwarn (loc, OPT_Wc__11_extensions,
-                "C++11 attributes "
-                "only available with %<-std=c++11%> or %<-std=gnu++11%>");
+       if (pedantic)
+         pedwarn (loc, OPT_Wc__11_extensions,
+                  "C++11 attributes "
+                  "only available with %<-std=c++11%> or %<-std=gnu++11%>");
        break;
       case CPP0X_REF_QUALIFIER:
        pedwarn (loc, OPT_Wc__11_extensions,

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index edfa5a494405f8ad79b04ac3f027abc255caeff7..64122d937fa505c1e4cebd6ab6a9639df552d357 100644 (file)
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -29924,11 +29924,10 @@ cp_nth_tokens_can_be_std_attribute_p (cp_parser *parser, size_t n)
 {
   cp_token *token = cp_lexer_peek_nth_token (parser->lexer, n);
 
-  return (cxx_dialect >= cxx11
-         && ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS)
-             || (token->type == CPP_OPEN_SQUARE
-                 && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1))
-                 && token->type == CPP_OPEN_SQUARE)));
+  return ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS)
+         || (token->type == CPP_OPEN_SQUARE
+             && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1))
+             && token->type == CPP_OPEN_SQUARE));
 }
 
 /* Return TRUE iff the next Nth tokens in the stream are possibly the

diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C
index c2cf912047e9803493cece9693d87e22dfe62aa1..b1625d9691675ee4bfc6b3d8a0b8b13997a6e37f 100644 (file)
--- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C
@@ -1,3 +1,3 @@
-// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-c++11-extensions" }
 
 int **** [[gnu::format(printf, 1, 2)]] foo(const char *, ...); // { dg-warning "only applies to function types" }

diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C
index 504b4565679c489469a7663e9d108e6987911cfd..040f15c9dbb94bcda3d7040b1ade0b94c75028e3 100644 (file)
--- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C
@@ -1,4 +1,4 @@
-// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-c++11-extensions" }
 // PR c++/13791
 
 template <typename T> struct O {

diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C
index a1b4a84b7e5494f252ea4fa4888635117ec09f9b..8997b845dfd95270cf57f72bc8942c011467a3c6 100644 (file)
--- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C
@@ -1,4 +1,4 @@
-// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-c++11-extensions" }
 // PR c++/13854
 
 extern char *rindex [[gnu::__pure__]] (__const char *__s, int __c) throw ();

diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C
index bf05dbeb31b96ff9ac72f8cb36abb56a4ed55ec3..8b552ca1fbe2dfaced7036965c25bce2d511a322 100644 (file)
--- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C
@@ -1,4 +1,4 @@
-// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wno-c++11-extensions" }
 // PR c++/15317
 
 struct A

diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C
index bac80aa02ffb015b6ca11a364ddcbe2da594550e..c2a328c7c7ffc09b9053f03fcf083091e25239a4 100644 (file)
--- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C
+++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C
@@ -1,6 +1,6 @@
 // PR c++/101582
 // { dg-do compile }
-// { dg-options "" }
+// { dg-options "-pedantic -Wno-extra-semi" }
 
 ;
 [[]] [[]] [[]];        // { dg-warning "attributes only available with" "" { target c++98_only } }
@@ -12,9 +12,9 @@ extern "C" [[]];      // { dg-warning "attributes only available with" "" { target c+
 extern "C" extern "C" ;
 extern "C" extern "C" [[]][[]][[]];    // { dg-warning "attributes only available with" "" { target c++98_only } }
 __extension__ ;
-__extension__ [[]];                    // { dg-warning "attributes only available with" "" { target c++98_only } }
+__extension__ [[]];
 __extension__ __extension__ ;
-__extension__ __extension__ [[]][[]];  // { dg-warning "attributes only available with" "" { target c++98_only } }
+__extension__ __extension__ [[]][[]];
 
 namespace N {
 
@@ -28,8 +28,8 @@ extern "C" [[]];      // { dg-warning "attributes only available with" "" { target c+
 extern "C" extern "C" ;
 extern "C" extern "C" [[]][[]][[]];    // { dg-warning "attributes only available with" "" { target c++98_only } }
 __extension__ ;
-__extension__ [[]];                    // { dg-warning "attributes only available with" "" { target c++98_only } }
+__extension__ [[]];
 __extension__ __extension__ ;
-__extension__ __extension__ [[]][[]];  // { dg-warning "attributes only available with" "" { target c++98_only } }
+__extension__ __extension__ [[]][[]];
 
 }