Re: Add the latest C++ SD-6 additions.

2014-11-12 Thread Markus Trippelsdorf 
On 2014.11.11 at 19:15 +0100, Markus Trippelsdorf wrote:
 On 2014.11.10 at 10:55 -0500, Ed Smith-Rowland wrote:
  On 11/09/2014 11:45 PM, Jason Merrill wrote:
   On 11/09/2014 08:33 PM, Ed Smith-Rowland wrote:
   +  //cpp_hashnode *node = 0;
   +  //node = token-val.node.node;
   +  //if (node)
   +  //  pfile-mi_ind_cmacro = node;
  
   Remove this commented-out code?
  
   The patch is OK.
  
   Jason
  
  
  Here is the committed patch.  It has those comments removed and has some 
  test case cleanup.
 
 This patch causes numerous segfaults when building Firefox, e.g.:

 trippels@gcc1-power7 gecko-dev % /home/trippels/gcc_test/usr/local/bin/g++ -I 
 /home/trippels/gecko-dev/intl/icu/source/common -MM test.cpp
 built-in: internal compiler error: Segmentation fault
 0x109b64ab crash_signal
 ../../gcc/gcc/toplev.c:358
 0x110b3d30 parse_has_attribute
 ../../gcc/libcpp/expr.c:2165
 0x110b3d30 eval_token
 ../../gcc/libcpp/expr.c:1059
 0x110b3d30 _cpp_parse_expr
 ../../gcc/libcpp/expr.c:1227
 Please submit a full bug report,

I've opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63831 with a
testcase.

-- 
Markus

Re: Add the latest C++ SD-6 additions.

2014-11-11 Thread Jason Merrill 

On 11/11/2014 12:52 AM, Ed Smith-Rowland wrote:

I'll might put this to the SD-6 list because it would be nice to have
clarity - even if it's implementation defined.


Sounds good.  I was thinking that defining to 0 tells the user this 
isn't supported which seems more useful than this may or may not be 
supported.


Jason

Re: Add the latest C++ SD-6 additions.

2014-11-11 Thread Markus Trippelsdorf 
On 2014.11.10 at 10:55 -0500, Ed Smith-Rowland wrote:
 On 11/09/2014 11:45 PM, Jason Merrill wrote:
  On 11/09/2014 08:33 PM, Ed Smith-Rowland wrote:
  +  //cpp_hashnode *node = 0;
  +  //node = token-val.node.node;
  +  //if (node)
  +  //  pfile-mi_ind_cmacro = node;
 
  Remove this commented-out code?
 
  The patch is OK.
 
  Jason
 
 
 Here is the committed patch.  It has those comments removed and has some 
 test case cleanup.

This patch causes numerous segfaults when building Firefox, e.g.:

(4.9 is fine:)
trippels@gcc1-power7 gecko-dev % g++ -I 
/home/trippels/gecko-dev/intl/icu/source/common -MM test.cpp
test.o: test.cpp \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/utf_old.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/utf.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/umachine.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/ptypes.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/platform.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/uconfig.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/uvernum.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/urename.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/utf8.h \
 /home/trippels/gecko-dev/intl/icu/source/common/unicode/utf16.h

(trunk crashes:)
trippels@gcc1-power7 gecko-dev % /home/trippels/gcc_test/usr/local/bin/g++ -I 
/home/trippels/gecko-dev/intl/icu/source/common -MM test.cpp
built-in: internal compiler error: Segmentation fault
0x109b64ab crash_signal
../../gcc/gcc/toplev.c:358
0x110b3d30 parse_has_attribute
../../gcc/libcpp/expr.c:2165
0x110b3d30 eval_token
../../gcc/libcpp/expr.c:1059
0x110b3d30 _cpp_parse_expr
../../gcc/libcpp/expr.c:1227
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See http://gcc.gnu.org/bugs.html for instructions.


-- 
Markus

Re: Add the latest C++ SD-6 additions.

2014-11-10 Thread Ed Smith-Rowland 

On 11/10/2014 12:10 PM, Jason Merrill wrote:

On 11/10/2014 10:55 AM, Ed Smith-Rowland wrote:

Would a 4.9 version be accepted?


Sure.

What do you think about defining the macros for unsupported features 
to 0 rather than leaving them undefined?  The document doesn't seem to 
specify.


Jason



Jason,

1. Undefined macros evaluate to 0 so that's effectively what we have now 
- no change in behavior if we explicitly set them
2. The SD-6 document advertises direct use of macros with #if 
__cpp_foobar without #ifdef - However if people are using #ifdef rather 
than #if that might break things (I guess that's different behavior); 
OTOH those dates are there for a reason.
3. OTOH, the SD-6 document seems to suggest only adding a macro as a 
feature is implemented or allowed bycompiler flags - implying undefined 
macros for unimplemented features
4. __has_include and __has_cpp_attribute return 0 on 
non-existent/undefined so there's some precedent (though these are 
rather different structurally - function macros)


So I'm conflicted after being initially sympathetic to defining as 
zero.  Still slightly in favor.


I'll might put this to the SD-6 list because it would be nice to have 
clarity - even if it's implementation defined.


Ed

Re: Add the latest C++ SD-6 additions.

2014-11-10 Thread Ed Smith-Rowland 

On 11/09/2014 11:45 PM, Jason Merrill wrote:

On 11/09/2014 08:33 PM, Ed Smith-Rowland wrote:

+  //cpp_hashnode *node = 0;
+  //node = token-val.node.node;
+  //if (node)
+  //  pfile-mi_ind_cmacro = node;


Remove this commented-out code?

The patch is OK.

Jason


Here is the committed patch.  It has those comments removed and has some 
test case cleanup.


Would a 4.9 version be accepted?

Thanks,

Ed

Index: libcpp/include/cpplib.h
===
--- libcpp/include/cpplib.h (revision 217269)
+++ libcpp/include/cpplib.h (working copy)
@@ -580,6 +580,9 @@
  Second argument is the location of the start of the current expansion.  */
   void (*used) (cpp_reader *, source_location, cpp_hashnode *);
 
+  /* Callback to identify whether an attribute exists.  */
+  int (*has_attribute) (cpp_reader *);
+
   /* Callback that can change a user builtin into normal macro.  */
   bool (*user_builtin_macro) (cpp_reader *, cpp_hashnode *);
 };
Index: libcpp/internal.h
===
--- libcpp/internal.h   (revision 217269)
+++ libcpp/internal.h   (working copy)
@@ -261,6 +261,9 @@
   /* Nonzero if in a __has_include__ or __has_include_next__ statement.  */
   unsigned char in__has_include__;
 
+  /* Nonzero if in a __has_attribute__ statement.  */
+  unsigned char in__has_attribute__;
+
   /* Nonzero if prevent_expansion is true only because output is
  being discarded.  */
   unsigned char discarding_output;
@@ -284,6 +287,7 @@
   cpp_hashnode *n__VA_ARGS__;  /* C99 vararg macros */
   cpp_hashnode *n__has_include__;  /* __has_include__ operator */
   cpp_hashnode *n__has_include_next__; /* __has_include_next__ operator */
+  cpp_hashnode *n__has_attribute__;/* __has_attribute__ operator */
 };
 
 typedef struct _cpp_line_note _cpp_line_note;
Index: libcpp/directives.c
===
--- libcpp/directives.c (revision 217269)
+++ libcpp/directives.c (working copy)
@@ -571,6 +571,10 @@
 || node == pfile-spec_nodes.n__has_include_next__))
cpp_error (pfile, CPP_DL_ERROR,
   \__has_include__\ cannot be used as a macro name);
+  else if (is_def_or_undef
+node == pfile-spec_nodes.n__has_attribute__)
+   cpp_error (pfile, CPP_DL_ERROR,
+  \__has_attribute__\ cannot be used as a macro name);
   else if (! (node-flags  NODE_POISONED))
return node;
 }
Index: libcpp/expr.c
===
--- libcpp/expr.c   (revision 217269)
+++ libcpp/expr.c   (working copy)
@@ -65,6 +65,7 @@
 static void check_promotion (cpp_reader *, const struct op *);
 
 static cpp_num parse_has_include (cpp_reader *, enum include_type);
+static cpp_num parse_has_attribute (cpp_reader *);
 
 /* Token type abuse to create unary plus and minus operators.  */
 #define CPP_UPLUS ((enum cpp_ttype) (CPP_LAST_CPP_OP + 1))
@@ -1054,6 +1055,8 @@
return parse_has_include (pfile, IT_INCLUDE);
   else if (token-val.node.node == pfile-spec_nodes.n__has_include_next__)
return parse_has_include (pfile, IT_INCLUDE_NEXT);
+  else if (token-val.node.node == pfile-spec_nodes.n__has_attribute__)
+   return parse_has_attribute (pfile);
   else if (CPP_OPTION (pfile, cplusplus)
(token-val.node.node == pfile-spec_nodes.n_true
   || token-val.node.node == pfile-spec_nodes.n_false))
@@ -2147,3 +2150,21 @@
 
   return result;
 }
+
+/* Handle meeting __has_attribute__ in a preprocessor expression.  */
+static cpp_num
+parse_has_attribute (cpp_reader *pfile)
+{
+  pfile-state.in__has_attribute__++;
+
+  cpp_num result;
+  result.unsignedp = false;
+  result.high = 0;
+  result.overflow = false;
+
+  result.low = pfile-cb.has_attribute (pfile);
+
+  pfile-state.in__has_attribute__--;
+
+  return result;
+}
Index: libcpp/identifiers.c
===
--- libcpp/identifiers.c(revision 217269)
+++ libcpp/identifiers.c(working copy)
@@ -72,6 +72,7 @@
   s-n__VA_ARGS__-flags |= NODE_DIAGNOSTIC;
   s-n__has_include__   = cpp_lookup (pfile, DSC(__has_include__));
   s-n__has_include_next__ = cpp_lookup (pfile, DSC(__has_include_next__));
+  s-n__has_attribute__   = cpp_lookup (pfile, DSC(__has_attribute__));
 }
 
 /* Tear down the identifier hash table.  */
Index: libcpp/pch.c
===
--- libcpp/pch.c(revision 217269)
+++ libcpp/pch.c(working copy)
@@ -835,6 +835,7 @@
 s-n__VA_ARGS__ = cpp_lookup (r, DSC(__VA_ARGS__));
 s-n__has_include__ = cpp_lookup (r, DSC(__has_include__));
 s-n__has_include_next__ = cpp_lookup (r, DSC(__has_include_next__));
+s-n__has_attribute__ = cpp_lookup (r, DSC(__has_attribute__));
   }
 
   old_state

Re: Add the latest C++ SD-6 additions.

2014-11-10 Thread Jason Merrill 

On 11/10/2014 10:55 AM, Ed Smith-Rowland wrote:

Would a 4.9 version be accepted?


Sure.

What do you think about defining the macros for unsupported features to 
0 rather than leaving them undefined?  The document doesn't seem to specify.


Jason

Add the latest C++ SD-6 additions.

2014-11-09 Thread Ed Smith-Rowland 
I would like to put this patch out before Stage 1 ends even if there is 
bikeshed renaming of macros in the next couple weeks as the C++ 
committee wraps up after their meeting.


The main part of this patch is a __has_cpp_attribute macro.
#if __has_cpp_attribute(foobar)
#else
#endif

In C++ we can use namespaces as well:
#if __has_cpp_attribute(gnu::foobar)
#else
#endif

I also added __has_attribute with the same sematics as an extension 
since clang has it.

I made these available to C as well as C++.

There are also two C++98 flags in SD-6 added since most compilers allow 
one to switch these features off:
__cpp_rtti, __cpp_exceptions.  These are not defined if -fno-rtti 
-fno-exceptions respectively.


Also, the macro __cpp_attribute_deprecated has been removed in favor of 
__has_cpp_attribute(deprecated).
Since __cpp_attribute_deprecated is out in the wild in the latest 
gcc-4.9 release perhaps I need to support this
even if, in an ironic twist, __cpp_attribute_deprecated is deprecated.  
Let me know.


This builds clean on x86_64-linux.

Is this OK once it passes testing?

Ed

libcpp:

2014-11-10  Edward Smith-Rowland  3dw...@verizon.net

* include/cpplib.h (cpp_callbacks): Add has_attribute.
* internal.h (lexer_state): Add in__has_attribute__.
* directives.c (lex_macro_node): Prevent use of __has_attribute__
as a macro.
* expr.c (parse_has_attribute): New function; (eval_token): Look for
__has_attribute__ and route to parse_has_attribute.
* identifiers.c (_cpp_init_hashtable): Initialize n__has_attribute__.
* pch.c (cpp_read_state): Initialize n__has_attribute__.
* traditional.c (enum ls): Add ls_has_attribute, ls_has_attribute_close;
(_cpp_scan_out_logical_line): Attend to __has_attribute__.


gcc/c-family:

2014-11-10  Edward Smith-Rowland  3dw...@verizon.net

* c-cppbuiltin.c (__has_attribute, __has_cpp_attribute): New macros;
(__cpp_rtti, __cpp_exceptions): New macros for C++98;
(__cpp_range_based_for, __cpp_initializer_lists,
__cpp_delegating_constructors, __cpp_nsdmi,
__cpp_inheriting_constructors, __cpp_ref_qualifiers): New macros
for C++11; (__cpp_attribute_deprecated): Remove in favor of
__has_cpp_attribute.
* c-lex.c (cb_has_attribute): New callback CPP function;
(init_c_lex): Set has_attribute callback.


gcc/testsuite:

2014-11-10  Edward Smith-Rowland  3dw...@verizon.net

* g++.dg/cpp1y/feat-cxx11.C: Test new feature macros for C++98
and C++11; Test existence of __has_cpp_attribute;  Test C++11
attributes.
* g++.dg/cpp1y/feat-cxx11-neg.C: Ditto.
* g++.dg/cpp1y/feat-cxx14.C: Ditto and test for C++14 attributes.
* g++.dg/cpp1y/feat-cxx98.C: Test new feature macros for C++98.
* g++.dg/cpp1y/feat-cxx98-neg.C: Ditto.
* g++.dg/cpp1y/feat-neg.C: Test that __cpp_rtti, _cpp_exceptions
will be undefined for -fno-rtti -fno-exceptions.
Index: libcpp/include/cpplib.h
===
--- libcpp/include/cpplib.h (revision 217269)
+++ libcpp/include/cpplib.h (working copy)
@@ -580,6 +580,9 @@
  Second argument is the location of the start of the current expansion.  */
   void (*used) (cpp_reader *, source_location, cpp_hashnode *);
 
+  /* Callback to identify whether an attribute exists.  */
+  int (*has_attribute) (cpp_reader *);
+
   /* Callback that can change a user builtin into normal macro.  */
   bool (*user_builtin_macro) (cpp_reader *, cpp_hashnode *);
 };
Index: libcpp/internal.h
===
--- libcpp/internal.h   (revision 217269)
+++ libcpp/internal.h   (working copy)
@@ -261,6 +261,9 @@
   /* Nonzero if in a __has_include__ or __has_include_next__ statement.  */
   unsigned char in__has_include__;
 
+  /* Nonzero if in a __has_attribute__ statement.  */
+  unsigned char in__has_attribute__;
+
   /* Nonzero if prevent_expansion is true only because output is
  being discarded.  */
   unsigned char discarding_output;
@@ -284,6 +287,7 @@
   cpp_hashnode *n__VA_ARGS__;  /* C99 vararg macros */
   cpp_hashnode *n__has_include__;  /* __has_include__ operator */
   cpp_hashnode *n__has_include_next__; /* __has_include_next__ operator */
+  cpp_hashnode *n__has_attribute__;/* __has_attribute__ operator */
 };
 
 typedef struct _cpp_line_note _cpp_line_note;
Index: libcpp/directives.c
===
--- libcpp/directives.c (revision 217269)
+++ libcpp/directives.c (working copy)
@@ -571,6 +571,10 @@
 || node == pfile-spec_nodes.n__has_include_next__))
cpp_error (pfile, CPP_DL_ERROR,
   \__has_include__\ cannot be used as a macro name);
+  else if (is_def_or_undef
+node == pfile-spec_nodes.n__has_attribute__)
+   cpp_error (pfile,

Re: Add the latest C++ SD-6 additions.

2014-11-09 Thread Jason Merrill 

On 11/09/2014 08:33 PM, Ed Smith-Rowland wrote:

+  //cpp_hashnode *node = 0;
+  //node = token-val.node.node;
+  //if (node)
+  //  pfile-mi_ind_cmacro = node;


Remove this commented-out code?

The patch is OK.

Jason