binutils-gdb/gdb/common/common-defs.h
Simon Marchi 6242c6a690 darwin: Don't use sbrk
This patch gets rid of this warning on macOS:

    CXX    main.o
  /Users/simark/src/binutils-gdb/gdb/main.c:492:27: error: 'sbrk' is deprecated [-Werror,-Wdeprecated-declarations]
    lim_at_start = (char *) sbrk (0);
                            ^
  /usr/include/unistd.h:585:1: note: 'sbrk' has been explicitly marked deprecated here
  __deprecated __WATCHOS_PROHIBITED __TVOS_PROHIBITED
  ^
  /usr/include/sys/cdefs.h:176:37: note: expanded from macro '__deprecated'
  #define __deprecated    __attribute__((deprecated))
                                         ^

sbrk on macOS is not useful for our purposes, since sbrk(0) always
returns the same value.  From what I read, brk/sbrk on macOS is just an
emulation, it always returns a pointer in a 4MB section reserved for
that.

So instead of letting users use "maint set per-command space on" and
print silly results, I think we should just disable that feature for
this platform (as we do for platforms that don't have sbrk).

I defined a HAVE_USEFUL_SBRK macro and used that instead of HAVE_SBRK.

gdb/ChangeLog:

	* common/common-defs.h (HAVE_USEFUL_SBRK): Define.
	* main.c: Use HAVE_USEFUL_SBRK instead of HAVE_SBRK.
	* maint.c: Likewise.
	* top.c: Likewise.
2018-07-04 12:40:25 -04:00

118 lines
3.5 KiB
C

/* Common definitions.
Copyright (C) 1986-2018 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef COMMON_DEFS_H
#define COMMON_DEFS_H
#include "config.h"
#undef PACKAGE_NAME
#undef PACKAGE_VERSION
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#ifdef GDBSERVER
#include "build-gnulib-gdbserver/config.h"
#else
#include "build-gnulib/config.h"
#endif
#undef PACKAGE_NAME
#undef PACKAGE_VERSION
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
/* From:
https://www.gnu.org/software/gnulib/manual/html_node/stdint_002eh.html
"On some hosts that predate C++11, when using C++ one must define
__STDC_CONSTANT_MACROS to make visible the definitions of constant
macros such as INTMAX_C, and one must define __STDC_LIMIT_MACROS to
make visible the definitions of limit macros such as INTMAX_MAX.".
And:
https://www.gnu.org/software/gnulib/manual/html_node/inttypes_002eh.html
"On some hosts that predate C++11, when using C++ one must define
__STDC_FORMAT_MACROS to make visible the declarations of format
macros such as PRIdMAX."
Must do this before including any system header, since other system
headers may include stdint.h/inttypes.h. */
#define __STDC_CONSTANT_MACROS 1
#define __STDC_LIMIT_MACROS 1
#define __STDC_FORMAT_MACROS 1
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#ifdef HAVE_STRINGS_H
#include <strings.h> /* for strcasecmp and strncasecmp */
#endif
#include <errno.h>
#include <alloca.h>
#include "ansidecl.h"
/* This is defined by ansidecl.h, but we prefer gnulib's version. On
MinGW, gnulib might enable __USE_MINGW_ANSI_STDIO, which may or not
require use of attribute gnu_printf instead of printf. gnulib
checks that at configure time. Since _GL_ATTRIBUTE_FORMAT_PRINTF
is compatible with ATTRIBUTE_PRINTF, simply use it. */
#undef ATTRIBUTE_PRINTF
#define ATTRIBUTE_PRINTF _GL_ATTRIBUTE_FORMAT_PRINTF
#include "libiberty.h"
#include "pathmax.h"
#include "gdb/signals.h"
#include "gdb_locale.h"
#include "ptid.h"
#include "common-types.h"
#include "common-utils.h"
#include "gdb_assert.h"
#include "errors.h"
#include "print-utils.h"
#include "common-debug.h"
#include "cleanups.h"
#include "common-exceptions.h"
#include "common/poison.h"
#define EXTERN_C extern "C"
#define EXTERN_C_PUSH extern "C" {
#define EXTERN_C_POP }
/* Pull in gdb::unique_xmalloc_ptr. */
#include "common/gdb_unique_ptr.h"
/* String containing the current directory (what getwd would return). */
extern char *current_directory;
/* sbrk on macOS is not useful for our purposes, since sbrk(0) always
returns the same value. brk/sbrk on macOS is just an emulation
that always returns a pointer to a 4MB section reserved for
that. */
#if defined (HAVE_SBRK) && !__APPLE__
#define HAVE_USEFUL_SBRK 1
#endif
#endif /* COMMON_DEFS_H */