--- /dev/null
+/* This header file provides the reentrancy. */
+
+/* The reentrant system calls here serve two purposes:
+
+ 1) Provide reentrant versions of the system calls the ANSI C library
+ requires.
+ 2) Provide these system calls in a namespace clean way.
+
+ It is intended that *all* system calls that the ANSI C library needs
+ be declared here. It documents them all in one place. All library access
+ to the system is via some form of these functions.
+
+ The target may provide the needed syscalls by any of the following:
+
+ 1) Define the reentrant versions of the syscalls directly.
+ (eg: _open_r, _close_r, etc.). Please keep the namespace clean.
+ When you do this, set "syscall_dir" to "syscalls" and add
+ -DREENTRANT_SYSCALLS_PROVIDED to newlib_cflags in configure.host.
+
+ 2) Define namespace clean versions of the system calls by prefixing
+ them with '_' (eg: _open, _close, etc.). Technically, there won't be
+ true reentrancy at the syscall level, but the library will be namespace
+ clean.
+ When you do this, set "syscall_dir" to "syscalls" in configure.host.
+
+ 3) Define or otherwise provide the regular versions of the syscalls
+ (eg: open, close, etc.). The library won't be reentrant nor namespace
+ clean, but at least it will work.
+ When you do this, add -DMISSING_SYSCALL_NAMES to newlib_cflags in
+ configure.host.
+
+ 4) Define or otherwise provide the regular versions of the syscalls,
+ and do not supply functional interfaces for any of the reentrant
+ calls. With this method, the reentrant syscalls are redefined to
+ directly call the regular system call without the reentrancy argument.
+ When you do this, specify both -DREENTRANT_SYSCALLS_PROVIDED and
+ -DMISSING_SYSCALL_NAMES via newlib_cflags in configure.host and do
+ not specify "syscall_dir".
+
+ Stubs of the reentrant versions of the syscalls exist in the libc/reent
+ source directory and are provided if REENTRANT_SYSCALLS_PROVIDED isn't
+ defined. These stubs call the native system calls: _open, _close, etc.
+ if MISSING_SYSCALL_NAMES is *not* defined, otherwise they call the
+ non-underscored versions: open, close, etc. when MISSING_SYSCALL_NAMES
+ *is* defined.
+
+ By default, newlib functions call the reentrant syscalls internally,
+ passing a reentrancy structure as an argument. This reentrancy structure
+ contains data that is thread-specific. For example, the errno value is
+ kept in the reentrancy structure. If multiple threads exist, each will
+ keep a separate errno value which is intuitive since the application flow
+ cannot check for failure reliably otherwise.
+
+ The reentrant syscalls are either provided by the platform, by the
+ libc/reent stubs, or in the case of both MISSING_SYSCALL_NAMES and
+ REENTRANT_SYSCALLS_PROVIDED being defined, the calls are redefined to
+ simply call the regular syscalls with no reentrancy struct argument.
+
+ A single-threaded application does not need to worry about the reentrancy
+ structure. It is used internally.
+
+ A multi-threaded application needs either to manually manage reentrancy
+ structures or use dynamic reentrancy.
+
+ Manually managing reentrancy structures entails calling special reentrant
+ versions of newlib functions that have an additional reentrancy argument.
+ For example, _printf_r. By convention, the first argument is the
+ reentrancy structure. By default, the normal version of the function
+ uses the default reentrancy structure: _REENT. The reentrancy structure
+ is passed internally, eventually to the reentrant syscalls themselves.
+ How the structures are stored and accessed in this model is up to the
+ application.
+
+ Dynamic reentrancy is specified by the __DYNAMIC_REENT__ flag. This
+ flag denotes setting up a macro to replace _REENT with a function call
+ to __getreent(). This function needs to be implemented by the platform
+ and it is meant to return the reentrancy structure for the current
+ thread. When the regular C functions (e.g. printf) go to call internal
+ routines with the default _REENT structure, they end up calling with
+ the reentrancy structure for the thread. Thus, application code does not
+ need to call the _r routines nor worry about reentrancy structures. */
+
+/* WARNING: All identifiers here must begin with an underscore. This file is
+ included by stdio.h and others and we therefore must only use identifiers
+ in the namespace allotted to us. */
+
+#ifndef _REENT_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
+#define _REENT_H_
+
+#include <sys/reent.h>
+#include <sys/_types.h>
+#include <machine/types.h>
+
+#define __need_size_t
+#define __need_ptrdiff_t
+#include <stddef.h>
+
+/* FIXME: not namespace clean */
+struct stat;
+struct tms;
+struct timeval;
+struct timezone;
+
+#if defined(REENTRANT_SYSCALLS_PROVIDED) && defined(MISSING_SYSCALL_NAMES)
+
+#define _close_r(__reent, __fd) close(__fd)
+#define _execve_r(__reent, __f, __arg, __env) execve(__f, __arg, __env)
+#define _fcntl_r(__reent, __fd, __cmd, __arg) fcntl(__fd, __cmd, __arg)
+#define _fork_r(__reent) fork()
+#define _fstat_r(__reent, __fdes, __stat) fstat(__fdes, __stat)
+#define _getpid_r(__reent) getpid()
+#define _isatty_r(__reent, __desc) isatty(__desc)
+#define _kill_r(__reent, __pid, __signal) kill(__pid, __signal)
+#define _link_r(__reent, __oldpath, __newpath) link(__oldpath, __newpath)
+#define _lseek_r(__reent, __fdes, __off, __w) lseek(__fdes, __off, __w)
+#define _mkdir_r(__reent, __path, __m) mkdir(__path, __m)
+#define _open_r(__reent, __path, __flag, __m) open(__path, __flag, __m)
+#define _read_r(__reent, __fd, __buff, __cnt) read(__fd, __buff, __cnt)
+#define _rename_r(__reent, __old, __new) rename(__old, __new)
+#define _sbrk_r(__reent, __incr) sbrk(__incr)
+#define _stat_r(__reent, __path, __buff) stat(__path, __buff)
+#define _times_r(__reent, __time) times(__time)
+#define _unlink_r(__reent, __path) unlink(__path)
+#define _wait_r(__reent, __status) wait(__status)
+#define _write_r(__reent, __fd, __buff, __cnt) write(__fd, __buff, __cnt)
+#define _gettimeofday_r(__reent, __tp, __tzp) gettimeofday(__tp, __tzp)
+
+#ifdef __LARGE64_FILES
+#define _lseek64_r(__reent, __fd, __off, __w) lseek64(__fd, __off, __w)
+#define _fstat64_r(__reent, __fd, __buff) fstat64(__fd, __buff)
+#define _open64_r(__reent, __path, __flag, __m) open64(__path, __flag, __m)
+#endif
+
+#else
+/* Reentrant versions of system calls. */
+
+extern int _close_r _PARAMS ((struct _reent *, int));
+extern int _execve_r _PARAMS ((struct _reent *, const char *, char *const *, char *const *));
+extern int _fcntl_r _PARAMS ((struct _reent *, int, int, int));
+extern int _fork_r _PARAMS ((struct _reent *));
+extern int _fstat_r _PARAMS ((struct _reent *, int, struct stat *));
+extern int _getpid_r _PARAMS ((struct _reent *));
+extern int _isatty_r _PARAMS ((struct _reent *, int));
+extern int _kill_r _PARAMS ((struct _reent *, int, int));
+extern int _link_r _PARAMS ((struct _reent *, const char *, const char *));
+extern _off_t _lseek_r _PARAMS ((struct _reent *, int, _off_t, int));
+extern int _mkdir_r _PARAMS ((struct _reent *, const char *, int));
+extern int _open_r _PARAMS ((struct _reent *, const char *, int, int));
+extern _ssize_t _read_r _PARAMS ((struct _reent *, int, void *, size_t));
+extern int _rename_r _PARAMS ((struct _reent *, const char *, const char *));
+extern void *_sbrk_r _PARAMS ((struct _reent *, ptrdiff_t));
+extern int _stat_r _PARAMS ((struct _reent *, const char *, struct stat *));
+extern _CLOCK_T_ _times_r _PARAMS ((struct _reent *, struct tms *));
+extern int _unlink_r _PARAMS ((struct _reent *, const char *));
+extern int _wait_r _PARAMS ((struct _reent *, int *));
+extern _ssize_t _write_r _PARAMS ((struct _reent *, int, const void *, size_t));
+
+/* This one is not guaranteed to be available on all targets. */
+extern int _gettimeofday_r _PARAMS ((struct _reent *, struct timeval *__tp, void *__tzp));
+
+#ifdef __LARGE64_FILES
+
+#if defined(__CYGWIN__) && defined(_COMPILING_NEWLIB)
+#define stat64 __stat64
+#endif
+
+struct stat64;
+
+extern _off64_t _lseek64_r _PARAMS ((struct _reent *, int, _off64_t, int));
+extern int _fstat64_r _PARAMS ((struct _reent *, int, struct stat64 *));
+extern int _open64_r _PARAMS ((struct _reent *, const char *, int, int));
+extern int _stat64_r _PARAMS ((struct _reent *, const char *, struct stat64 *));
+#endif
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _REENT_H_ */
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