| Message ID | 559430F3.2040109@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Jul 01, 2015 at 02:26:59PM -0400, Jason Merrill wrote: > I've been threatening to do this for a couple of months, and now that the > regressions are under control I think it's time. This patch changes the > default C++ dialect to C++14. Great! It seems that our cppopts.texi is very outdated wrt C++ standards... Marek
On 07/01/2015 11:26 AM, Jason Merrill wrote: > I've been threatening to do this for a couple of months, and now that > the regressions are under control I think it's time. This patch changes > the default C++ dialect to C++14. > > Tested x86_64-pc-linux-gnu, applying to trunk. This causes a build failure on Ubuntu 14.04 LTS (Trusty) for x86_64 and armhf and probably others. All of the graphite*.c files fail with /home/wilson/FOSS/GCC/X-palantir/prev-x86_64-unknown-linux-gnu/libstdc++-v3/include/cstddef:51:11: error: â::max_align_tâ has not been declared using ::max_align_t; This is a known gmp problem, documented in PR56019 and in https://gcc.gnu.org/gcc-4.9/porting_to.html near the bottom where it discusses cstddef.h changes. Except the cstddef.h changes didn't matter until C++11 or later became the default. This is apparently fixed in gmp 6.0.0. I haven't had a chance to try that yet. The prereqs section on doc/install.texi says we need gmp 4.3.2 or later, so it appears that this needs to change too. This is maybe only a problem if you have the isl libraries installed. Jim
On 07/02/2015 12:10 AM, Jim Wilson wrote: > This is a known gmp problem, documented in PR56019 and in > https://gcc.gnu.org/gcc-4.9/porting_to.html > near the bottom where it discusses cstddef.h changes. This document also says that "A workaround until libraries get updated is to include <cstddef> or <stddef.h> before any headers from that library." Can you try modifying the graphite* files accordingly? Thanks, Jason
On Thu, 2 Jul 2015, Jason Merrill wrote: > On 07/02/2015 12:10 AM, Jim Wilson wrote: >> This is a known gmp problem, documented in PR56019 and in >> https://gcc.gnu.org/gcc-4.9/porting_to.html >> near the bottom where it discusses cstddef.h changes. > > This document also says that "A workaround until libraries get updated is to > include <cstddef> or <stddef.h> before any headers from that library." > > Can you try modifying the graphite* files accordingly? See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65988#c1 system.h looks like the right way to include gmp.h in gcc, currently.
On Thu, Jul 2, 2015 at 8:18 AM, Marc Glisse <marc.glisse@inria.fr> wrote: > On Thu, 2 Jul 2015, Jason Merrill wrote: > >> On 07/02/2015 12:10 AM, Jim Wilson wrote: >>> >>> This is a known gmp problem, documented in PR56019 and in >>> https://gcc.gnu.org/gcc-4.9/porting_to.html >>> near the bottom where it discusses cstddef.h changes. >> >> >> This document also says that "A workaround until libraries get updated is >> to include <cstddef> or <stddef.h> before any headers from that library." >> >> Can you try modifying the graphite* files accordingly? > > > See also > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65988#c1 > > system.h looks like the right way to include gmp.h in gcc, currently. Yeah, I _think_ the fix is to move the isl includes below the system.h include. Richard. > -- > Marc Glisse
On Thu, Jul 2, 2015 at 3:05 PM, Richard Biener <richard.guenther@gmail.com> wrote: > On Thu, Jul 2, 2015 at 8:18 AM, Marc Glisse <marc.glisse@inria.fr> wrote: >> On Thu, 2 Jul 2015, Jason Merrill wrote: >> >>> On 07/02/2015 12:10 AM, Jim Wilson wrote: >>>> >>>> This is a known gmp problem, documented in PR56019 and in >>>> https://gcc.gnu.org/gcc-4.9/porting_to.html >>>> near the bottom where it discusses cstddef.h changes. >>> >>> >>> This document also says that "A workaround until libraries get updated is >>> to include <cstddef> or <stddef.h> before any headers from that library." >>> >>> Can you try modifying the graphite* files accordingly? >> >> >> See also >> >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65988#c1 >> >> system.h looks like the right way to include gmp.h in gcc, currently. > > Yeah, I _think_ the fix is to move the isl includes below the system.h > include. And it should only affect the files including isl/val_gmp.h which includes gmp.h. > Richard. > >> -- >> Marc Glisse
On Thu, Jul 2, 2015 at 6:08 AM, Richard Biener <richard.guenther@gmail.com> wrote: > On Thu, Jul 2, 2015 at 3:05 PM, Richard Biener > <richard.guenther@gmail.com> wrote: >> Yeah, I _think_ the fix is to move the isl includes below the system.h >> include. I tried this, and got a conflict for pretty much every macro defined by ctype.h, e.g. /usr/include/c++/4.8/bits/locale_facets.h:240:53: error: macro "toupper" passed 2 arguments, but takes just 1 toupper(char_type *__lo, const char_type* __hi) const system.h includes safe-ctype.h which does #include <ctype.h> ... #undef toupper #define toupper(c) do_not_use_toupper_with_safe_ctype isl/int.h includes iostream which includes other header files that want to define ctype like functions and we get a conflict. I see that <ctype.h> doesn't define any macros when __cplusplus is defined, but if we disable the macro redefines in safe-ctype.h, it isn't very safe anymore. This is probably why the isl headers were deliberately included before system.h when the ISL support was first added. Jim
On Wed, Jul 1, 2015 at 11:26 AM, Jason Merrill <jason@redhat.com> wrote: > I've been threatening to do this for a couple of months, and now that the > regressions are under control I think it's time. This patch changes the > default C++ dialect to C++14. > > Tested x86_64-pc-linux-gnu, applying to trunk. This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66829
commit 6f2b3941ffb3734cecc05507dd8ed46f6a6d4f2d
Author: Jason Merrill <jason@redhat.com>
Date: Fri May 8 17:02:05 2015 -0500
gcc/c-family/
* c-opts.c (c_common_post_options): Default to C++14.
gcc/testsuite/
* lib/target-supports.exp (cxx_default): Set to C++14.
diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index 195045e..80481c3 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -889,9 +889,9 @@ c_common_post_options (const char **pfilename)
if (flag_abi_version == 0)
flag_abi_version = 10;
- /* Set C++ standard to C++98 if not specified on the command line. */
+ /* Set C++ standard to C++14 if not specified on the command line. */
if (c_dialect_cxx () && cxx_dialect == cxx_unset)
- set_std_cxx98 (/*ISO*/false);
+ set_std_cxx14 (/*ISO*/false);
if (cxx_dialect >= cxx11)
{
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index fc05e84..bf512e9 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -5935,7 +5935,7 @@ proc check_effective_target_c++ { } {
return 0
}
-set cxx_default "c++98"
+set cxx_default "c++14"
# Check whether the current active language standard supports the features
# of C++11/C++14 by checking for the presence of one of the -std flags.
# This assumes that the default for the compiler is $cxx_default, and that