[Bug libbacktrace/95012] New: [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[Bug libbacktrace/95012] New: [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

            Bug ID: 95012
           Summary: [mingw/gcc10.1] mmapio.c:69:14: error: implicit
                    declaration of function ‘getpagesize’
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libbacktrace
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xantares09 at hotmail dot com
                CC: ian at gcc dot gnu.org
  Target Milestone: ---

when updating archlinux mingw-w64-gcc from 9.3.0 to 10.1.0
I noticed that libbacktrace fails to build because of an extra "-Werror"
present during the compilation of libbacktrace that was not here for previous
versions:

libtool: compile: 
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/build-i686-w64-mingw32/./gcc/xgcc
-B/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/build-i686-w64-mingw32/./gcc/
-L/usr/i686-w64-mingw32/lib -L/usr/mingw/lib -isystem
/usr/i686-w64-mingw32/include -isystem /usr/mingw/include
-B/usr/i686-w64-mingw32/bin/ -B/usr/i686-w64-mingw32/lib/ -isystem
/usr/i686-w64-mingw32/include -isystem /usr/i686-w64-mingw32/sys-include
-DHAVE_CONFIG_H -I.
-I/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace -I
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace/../include
-I
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace/../libgcc
-I ../libgcc -funwind-tables -frandom-seed=mmapio.lo -W -Wall -Wwrite-strings
-Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition
-Wmissing-format-attribute -Wcast-qual -Werror -g -O2 -c
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace/mmapio.c
 -DDLL_EXPORT -DPIC -o .libs/mmapio.o
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace/mmapio.c:
In function ‘backtrace_get_view’:
/home/xantares/projects/aur-scripts/mingw-w64-gcc/src/gcc/libbacktrace/mmapio.c:69:14:
error: implicit declaration of function ‘getpagesize’
[-Werror=implicit-function-declaration]

[Bug libbacktrace/95012] [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

--- Comment #1 from xantares09 at hotmail dot com ---
the full compilation script can be seen here:
https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=mingw-w64-gcc

[Bug libbacktrace/95012] [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at airs dot com

--- Comment #2 from Ian Lance Taylor <ian at airs dot com> ---
Thanks for the bug report.  I can't see any relevant change in libbacktrace. 
As far as I can tell the call to getpagesize has been there for a while, and
the use of -Werror has been there for a while.

Does mingw-w64-gcc have a getpagesize function?  What header file declares it? 
Normally it is declared in <unistd.h>, but mmapio.c does #include that file.

[Bug libbacktrace/95012] [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

--- Comment #3 from xantares09 at hotmail dot com ---
mingw does not define getpagesize as far as I can tell with:
$ grep -nr getpagesize /usr/i686-w64-mingw32/include/

but gcc seems to detect it (9.x and 10.x):
checking for getpagesize... (cached) yes

maybe it relies on its own provided getpagesize function:
gcc/system.h:479:#if defined (HAVE_DECL_GETPAGESIZE) && !HAVE_DECL_GETPAGESIZE
gcc/system.h:480:extern int getpagesize (void);

[Bug libbacktrace/95012] [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Ian Lance Taylor <ian@gcc.gnu.org>:

https://gcc.gnu.org/g:47f4703c33c4936fd423c2a1180b2de144115d3d

commit r11-280-g47f4703c33c4936fd423c2a1180b2de144115d3d
Author: Ian Lance Taylor <iant@golang.org>
Date:   Mon May 11 10:51:21 2020 -0700

    libbacktrace: declare getpagesize if necessary

    libbacktrace/
            PR libbacktrace/95012
            * configure.ac: Check for getpagesize declaration.
            * mmap.c: Declare getpagesize if necessary.
            * mmapio.c: Likewise.

[Bug libbacktrace/95012] [mingw/gcc10.1] mmapio.c:69:14: error: implicit declaration of function ‘getpagesize’

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95012

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #5 from Ian Lance Taylor <ian at airs dot com> ---
Thanks, should be fixed on master.