libcpp/system.h

/* Get common system includes and various definitions and declarations based
   on autoconf macros.
   Copyright (C) 1998-2026 Free Software Foundation, Inc.

This file is part of GCC.

GCC 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, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */


#ifndef LIBCPP_SYSTEM_H
#define LIBCPP_SYSTEM_H

/* We must include stdarg.h before stdio.h.  */
#include <stdarg.h>

#ifdef HAVE_STDDEF_H
# include <stddef.h>
#endif
#ifdef HAVE_STDINT_H
# include <stdint.h>
#endif
#ifdef HAVE_INTTYPES_H
# include <inttypes.h>
#endif

#include <stdio.h>

#ifdef __cplusplus
#include <new>
#endif

/* Define a generic NULL if one hasn't already been defined.  */
#ifndef NULL
#define NULL 0
#endif

/* Use the unlocked open routines from libiberty.  */

/* Some of these are #define on some systems, e.g. on AIX to redirect
   the names to 64bit capable functions for LARGE_FILES support. These
   redefs are pointless here so we can override them.  */

#undef fopen
#undef freopen

#define fopen(PATH,MODE) fopen_unlocked(PATH,MODE)
#define fdopen(FILDES,MODE) fdopen_unlocked(FILDES,MODE)
#define freopen(PATH,MODE,STREAM) freopen_unlocked(PATH,MODE,STREAM)

/* The compiler is not a multi-threaded application and therefore we
   do not have to use the locking functions.  In fact, using the locking
   functions can cause the compiler to be significantly slower under
   I/O bound conditions (such as -g -O0 on very large source files).

   HAVE_DECL_PUTC_UNLOCKED actually indicates whether or not the stdio
   code is multi-thread safe by default.  If it is set to 0, then do
   not worry about using the _unlocked functions.

   fputs_unlocked, fwrite_unlocked, and fprintf_unlocked are
   extensions and need to be prototyped by hand (since we do not
   define _GNU_SOURCE).  */

#if defined HAVE_DECL_PUTC_UNLOCKED && HAVE_DECL_PUTC_UNLOCKED

# ifdef HAVE_PUTC_UNLOCKED
#  undef putc
#  define putc(C, Stream) putc_unlocked (C, Stream)
# endif
# ifdef HAVE_PUTCHAR_UNLOCKED
#  undef putchar
#  define putchar(C) putchar_unlocked (C)
# endif
# ifdef HAVE_GETC_UNLOCKED
#  undef getc
#  define getc(Stream) getc_unlocked (Stream)
# endif
# ifdef HAVE_GETCHAR_UNLOCKED
#  undef getchar
#  define getchar() getchar_unlocked ()
# endif
# ifdef HAVE_FPUTC_UNLOCKED
#  undef fputc
#  define fputc(C, Stream) fputc_unlocked (C, Stream)
# endif

#ifdef __cplusplus
extern "C" {
#endif

# ifdef HAVE_CLEARERR_UNLOCKED
#  undef clearerr
#  define clearerr(Stream) clearerr_unlocked (Stream)
#  if defined (HAVE_DECL_CLEARERR_UNLOCKED) && !HAVE_DECL_CLEARERR_UNLOCKED
extern void clearerr_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FEOF_UNLOCKED
#  undef feof
#  define feof(Stream) feof_unlocked (Stream)
#  if defined (HAVE_DECL_FEOF_UNLOCKED) && !HAVE_DECL_FEOF_UNLOCKED
extern int feof_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FILENO_UNLOCKED
#  undef fileno
#  define fileno(Stream) fileno_unlocked (Stream)
#  if defined (HAVE_DECL_FILENO_UNLOCKED) && !HAVE_DECL_FILENO_UNLOCKED
extern int fileno_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FFLUSH_UNLOCKED
#  undef fflush
#  define fflush(Stream) fflush_unlocked (Stream)
#  if defined (HAVE_DECL_FFLUSH_UNLOCKED) && !HAVE_DECL_FFLUSH_UNLOCKED
extern int fflush_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FGETC_UNLOCKED
#  undef fgetc
#  define fgetc(Stream) fgetc_unlocked (Stream)
#  if defined (HAVE_DECL_FGETC_UNLOCKED) && !HAVE_DECL_FGETC_UNLOCKED
extern int fgetc_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FGETS_UNLOCKED
#  undef fgets
#  define fgets(S, n, Stream) fgets_unlocked (S, n, Stream)
#  if defined (HAVE_DECL_FGETS_UNLOCKED) && !HAVE_DECL_FGETS_UNLOCKED
extern char *fgets_unlocked (char *, int, FILE *);
#  endif
# endif
# ifdef HAVE_FPUTS_UNLOCKED
#  undef fputs
#  define fputs(String, Stream) fputs_unlocked (String, Stream)
#  if defined (HAVE_DECL_FPUTS_UNLOCKED) && !HAVE_DECL_FPUTS_UNLOCKED
extern int fputs_unlocked (const char *, FILE *);
#  endif
# endif
# ifdef HAVE_FERROR_UNLOCKED
#  undef ferror
#  define ferror(Stream) ferror_unlocked (Stream)
#  if defined (HAVE_DECL_FERROR_UNLOCKED) && !HAVE_DECL_FERROR_UNLOCKED
extern int ferror_unlocked (FILE *);
#  endif
# endif
# ifdef HAVE_FREAD_UNLOCKED
#  undef fread
#  define fread(Ptr, Size, N, Stream) fread_unlocked (Ptr, Size, N, Stream)
#  if defined (HAVE_DECL_FREAD_UNLOCKED) && !HAVE_DECL_FREAD_UNLOCKED
extern size_t fread_unlocked (void *, size_t, size_t, FILE *);
#  endif
# endif
# ifdef HAVE_FWRITE_UNLOCKED
#  undef fwrite
#  define fwrite(Ptr, Size, N, Stream) fwrite_unlocked (Ptr, Size, N, Stream)
#  if defined (HAVE_DECL_FWRITE_UNLOCKED) && !HAVE_DECL_FWRITE_UNLOCKED
extern size_t fwrite_unlocked (const void *, size_t, size_t, FILE *);
#  endif
# endif
# ifdef HAVE_FPRINTF_UNLOCKED
#  undef fprintf
/* We can't use a function-like macro here because we don't know if
   we have varargs macros.  */
#  define fprintf fprintf_unlocked
#  if defined (HAVE_DECL_FPRINTF_UNLOCKED) && !HAVE_DECL_FPRINTF_UNLOCKED
extern int fprintf_unlocked (FILE *, const char *, ...);
#  endif
# endif

#ifdef __cplusplus
}
#endif

#endif

/* ??? Glibc's fwrite/fread_unlocked macros cause
   "warning: signed and unsigned type in conditional expression".  */
#undef fread_unlocked
#undef fwrite_unlocked

#include <sys/types.h>
#include <errno.h>

#if !defined (errno) && defined (HAVE_DECL_ERRNO) && !HAVE_DECL_ERRNO
extern int errno;
#endif

/* Some of glibc's string inlines cause warnings.  Plus we'd rather
   rely on (and therefore test) GCC's string builtins.  */
#define __NO_STRING_INLINES

#ifdef STRING_WITH_STRINGS
# include <string.h>
# include <strings.h>
#else
# ifdef HAVE_STRING_H
#  include <string.h>
# else
#  ifdef HAVE_STRINGS_H
#   include <strings.h>
#  endif
# endif
#endif

#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#if HAVE_LIMITS_H
# include <limits.h>
#endif

/* Infrastructure for defining missing _MAX and _MIN macros.  Note that
   macros defined with these cannot be used in #if.  */

/* The extra casts work around common compiler bugs.  */
#define INTTYPE_SIGNED(t) (! ((t) 0 < (t) -1))
/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
   It is necessary at least when t == time_t.  */
#define INTTYPE_MINIMUM(t) ((t) (INTTYPE_SIGNED (t) \
			    ? (t) 1 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
#define INTTYPE_MAXIMUM(t) ((t) (~ (t) 0 - INTTYPE_MINIMUM (t)))

/* Use that infrastructure to provide a few constants.  */
#ifndef UCHAR_MAX
# define UCHAR_MAX INTTYPE_MAXIMUM (unsigned char)
#endif

#ifdef TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  ifdef HAVE_TIME_H
#   include <time.h>
#  endif
# endif
#endif

#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#else
# ifdef HAVE_SYS_FILE_H
#  include <sys/file.h>
# endif
#endif

#ifdef HAVE_LOCALE_H
# include <locale.h>
#endif

#ifdef HAVE_LANGINFO_CODESET
# include <langinfo.h>
#endif

#ifndef HAVE_SETLOCALE
# define setlocale(category, locale) (locale)
#endif

#ifdef ENABLE_NLS
#include <libintl.h>
#else
/* Stubs.  */
# undef dgettext
# define dgettext(package, msgid) (msgid)
#endif

#ifndef _
# define _(msgid) dgettext (PACKAGE, msgid)
#endif

#ifndef N_
# define N_(msgid) msgid
#endif

/* Some systems define these in, e.g., param.h.  We undefine these names
   here to avoid the warnings.  We prefer to use our definitions since we
   know they are correct.  */

#undef MIN
#undef MAX
#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
#define MAX(X,Y) ((X) > (Y) ? (X) : (Y))

/* The HAVE_DECL_* macros are three-state, undefined, 0 or 1.  If they
   are defined to 0 then we must provide the relevant declaration
   here.  These checks will be in the undefined state while configure
   is running so be careful to test "defined (HAVE_DECL_*)".  */

#ifdef __cplusplus
extern "C" {
#endif

#if defined (HAVE_DECL_ABORT) && !HAVE_DECL_ABORT
extern void abort (void);
#endif

#ifdef __cplusplus
}
#endif

#if HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif

/* Test if something is a normal file.  */
#ifndef S_ISREG
#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif

/* Test if something is a directory.  */
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif

/* Test if something is a character special file.  */
#ifndef S_ISCHR
#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
#endif

/* Test if something is a block special file.  */
#ifndef S_ISBLK
#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
#endif

/* Test if something is a socket.  */
#ifndef S_ISSOCK
# ifdef S_IFSOCK
#   define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
# else
#   define S_ISSOCK(m) 0
# endif
#endif

/* Test if something is a FIFO.  */
#ifndef S_ISFIFO
# ifdef S_IFIFO
#  define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
# else
#  define S_ISFIFO(m) 0
# endif
#endif

/* Approximate O_NOCTTY and O_BINARY.  */
#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif
#ifndef O_BINARY
# define O_BINARY 0
#endif

/* Filename handling macros.  */
#include "filenames.h"

/* Get libiberty declarations.  */
#include "libiberty.h"
#include "safe-ctype.h"

/* 1 if we have C99 designated initializers.

   ??? C99 designated initializers are not supported by most C++
   compilers, including G++.  -- gdr, 2005-05-18  */
#if !defined(HAVE_DESIGNATED_INITIALIZERS)
#ifdef __cplusplus
#define HAVE_DESIGNATED_INITIALIZERS 0
#else
#define HAVE_DESIGNATED_INITIALIZERS \
   ((GCC_VERSION >= 2007) || (__STDC_VERSION__ >= 199901L))
#endif
#endif

#ifndef offsetof
#define offsetof(TYPE, MEMBER)	((size_t) &((TYPE *) 0)->MEMBER)
#endif

/* __builtin_expect(A, B) evaluates to A, but notifies the compiler that
   the most likely value of A is B.  This feature was added at some point
   between 2.95 and 3.0.  Let's use 3.0 as the lower bound for now.  */
#if (GCC_VERSION < 3000)
#define __builtin_expect(a, b) (a)
#endif

/* Redefine abort to report an internal error w/o coredump, and
   reporting the location of the error in the source file.  */
extern void fancy_abort (const char *, int, const char *) ATTRIBUTE_NORETURN;
#define abort() fancy_abort (__FILE__, __LINE__, __FUNCTION__)

/* Use gcc_assert(EXPR) to test invariants.  */
#if ENABLE_ASSERT_CHECKING
#define gcc_assert(EXPR) 						\
   ((void)(!(EXPR) ? fancy_abort (__FILE__, __LINE__, __FUNCTION__), 0 : 0))
#elif (GCC_VERSION >= 4005)
#define gcc_assert(EXPR) 						\
  ((void)(__builtin_expect (!(EXPR), 0) ? __builtin_unreachable (), 0 : 0))
#else
/* Include EXPR, so that unused variable warnings do not occur.  */
#define gcc_assert(EXPR) ((void)(0 && (EXPR)))
#endif

#if CHECKING_P
#define gcc_checking_assert(EXPR) gcc_assert (EXPR)
#else
/* N.B.: in release build EXPR is not evaluated.  */
#define gcc_checking_assert(EXPR) ((void)(0 && (EXPR)))
#endif

#ifdef __has_cpp_attribute
# if __has_cpp_attribute(likely)
#  define ATTR_LIKELY [[likely]]
# elif __has_cpp_attribute(__likely__)
#  define ATTR_LIKELY [[__likely__]]
# else
#  define ATTR_LIKELY
# endif
#else
# define ATTR_LIKELY
#endif

/* Poison identifiers we do not want to use.  */
#if (GCC_VERSION >= 3000)
#undef calloc
#undef strdup
#undef malloc
#undef realloc
 #pragma GCC poison calloc strdup
 #pragma GCC poison malloc realloc

/* Libiberty macros that are no longer used in GCC.  */
#undef ANSI_PROTOTYPES
#undef PTR_CONST
#undef LONG_DOUBLE
#undef VPARAMS
#undef VA_OPEN
#undef VA_FIXEDARG
#undef VA_CLOSE
#undef VA_START
 #pragma GCC poison ANSI_PROTOTYPES PTR_CONST LONG_DOUBLE VPARAMS VA_OPEN \
  VA_FIXEDARG VA_CLOSE VA_START

/* Note: not all uses of the `index' token (e.g. variable names and
   structure members) have been eliminated.  */
#undef bcopy
#undef bzero
#undef bcmp
#undef rindex
 #pragma GCC poison bcopy bzero bcmp rindex

#endif /* GCC >= 3.0 */
#endif /* ! LIBCPP_SYSTEM_H */