On Sun, 30 Apr 2017, David Gressett wrote:
On Sun, 30 Apr 2017, Marc Glisse wrote:
On Sun, 30 Apr 2017, David Gressett wrote:
I'm working on getting the 32-bit MinGW platform on Windows updated to
a newer gcc than the gcc 5.3.0 thst is provided by the 32-bit MinGW
installer Iwas able to build gcc 5.4.0 and 6.3.0 with only
minor\difficulties, but the 7.0.1 release candidates do not build.
The problem occurs when xgcc attempts to compile this:
libstdc++-v3/libsupc++/new_opa.cc
The error messages are as follows:
new_opa.cc: In function 'void* operator new(std::size_t, std::align_val_t)':
new_opa.cc:36:30: error: '_aligned_malloc' was not declared in this
scope #define aligned_alloc(al,sz) _aligned_malloc(sz,al)
new_opa.cc:103:33: note: in expansion of macro 'aligned_alloc'
while (__builtin_expect ((p = aligned_alloc (align, sz)) == 0, false))
^~~~~~~~~~~~~
new_opa.cc:36:30: note: suggested alternative: 'aligned_alloc'
#define aligned_alloc(al,sz) _aligned_malloc(sz,al)
^
new_opa.cc:103:33: note: in expansion of macro 'aligned_alloc'
while (__builtin_expect ((p = aligned_alloc (align, sz)) == 0, false))
^~~~~~~~~~~~~ My searches in the
source code for _aligned_malloc found a changelog entry for Bugzilla
PR libstdc++/79190, which is not for Windows - it is for HP-UX 11.00.
I did see, however, in comment 6 of bug report 79190, the following
reference to Windows:
"We are using _aligned_malloc / _aligned_free on Windows, so it has to
be the case that alignment matches in allocation and deallocation."
There are no details about which kind of Windows gcc this is in
(Cygwin?), but this suggests that a fix for MinGW should be simple. I
would like to be able to supply a fix for this before gcc 7 is
released, but I don't know nearly enough about the details of how gcc is configured to do that before the release date.
According to the documentation, we may be missing a #include <malloc.h> in new_opa.cc, but if that's the case, it is strange that noone noticed before... Does >adding this #include help?
#include <malloc.h> has no effect.
Well, at this point, since you are the one with access to your system, it
is your job to find out where _aligned_malloc is declared, protected by
what flags, and most importantly what differs between the compilation of
new_opa.cc (see the command before the error message in the output of
make) and the test in libstdc++'s configure that determined that it could
define _GLIBCXX_HAVE__ALIGNED_MALLOC (see config.log in the right
directory).
--
Marc Glisse
