esp-idf/components/newlib/include/sys/config.h

#ifndef __SYS_CONFIG_H__
#define __SYS_CONFIG_H__

#include <machine/ieeefp.h>  /* floating point macros */
#include <sys/features.h>	/* POSIX defs */

#ifdef __aarch64__
#define MALLOC_ALIGNMENT 16
#endif

/* exceptions first */
#if defined(__H8500__) || defined(__W65__)
#define __SMALL_BITFIELDS
/* ???  This conditional is true for the h8500 and the w65, defining H8300
   in those cases probably isn't the right thing to do.  */
#define H8300 1
#endif

/* 16 bit integer machines */
#if defined(__Z8001__) || defined(__Z8002__) || defined(__H8500__) || defined(__W65__) || defined (__mn10200__) || defined (__AVR__)

#undef INT_MAX
#undef UINT_MAX
#define INT_MAX 32767
#define UINT_MAX 65535
#endif

#if defined (__H8300__) || defined (__H8300H__) || defined(__H8300S__) || defined (__H8300SX__)
#define __SMALL_BITFIELDS
#define H8300 1
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX __INT_MAX__
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#endif

#if (defined(__CR16__) || defined(__CR16C__) ||defined(__CR16CP__))
#ifndef __INT32__
#define __SMALL_BITFIELDS      
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX 32767
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#else /* INT32 */
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX 2147483647
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#endif /* INT32 */

#endif /* CR16C */

#if defined (__xc16x__) || defined (__xc16xL__) || defined (__xc16xS__)
#define __SMALL_BITFIELDS
#endif

#ifdef __W65__
#define __SMALL_BITFIELDS
#endif

#if defined(__D10V__)
#define __SMALL_BITFIELDS
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX __INT_MAX__
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#define _POINTER_INT short
#endif

#if defined(__mc68hc11__) || defined(__mc68hc12__) || defined(__mc68hc1x__)
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX __INT_MAX__
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#define _POINTER_INT short
#endif

#if defined(__m68k__) || defined(__mc68000__)
#define _READ_WRITE_RETURN_TYPE _ssize_t
#endif

#ifdef ___AM29K__
#define _FLOAT_RET double
#endif

#ifdef __i386__
#ifndef __unix__
/* in other words, go32 */
#define _FLOAT_RET double
#endif
#if defined(__linux__) || defined(__RDOS__)
/* we want the reentrancy structure to be returned by a function */
#define __DYNAMIC_REENT__
#define HAVE_GETDATE
#define _HAVE_SYSTYPES
#define _READ_WRITE_RETURN_TYPE _ssize_t
#define __LARGE64_FILES 1
/* we use some glibc header files so turn on glibc large file feature */
#define _LARGEFILE64_SOURCE 1
#endif
#endif

#ifdef __mn10200__
#define __SMALL_BITFIELDS
#endif

#ifdef __AVR__
#define __SMALL_BITFIELDS
#define _POINTER_INT short
#endif

#ifdef __v850
#define __ATTRIBUTE_IMPURE_PTR__ __attribute__((__sda__))
#endif

/* For the PowerPC eabi, force the _impure_ptr to be in .sdata */
#if defined(__PPC__)
#if defined(_CALL_SYSV)
#define __ATTRIBUTE_IMPURE_PTR__ __attribute__((__section__(".sdata")))
#endif
#ifdef __SPE__
#define _LONG_DOUBLE double
#endif
#endif

/* Configure small REENT structure for Xilinx MicroBlaze platforms */
#if defined (__MICROBLAZE__)
#ifndef _REENT_SMALL
#define _REENT_SMALL
#endif
/* Xilinx XMK uses Unix98 mutex */
#ifdef __XMK__
#define _UNIX98_THREAD_MUTEX_ATTRIBUTES
#endif
#endif

#if defined(__mips__) && !defined(__rtems__)
#define __ATTRIBUTE_IMPURE_PTR__ __attribute__((__section__(".sdata")))
#endif

#ifdef __xstormy16__
#define __SMALL_BITFIELDS
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX __INT_MAX__
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#define MALLOC_ALIGNMENT 8
#define _POINTER_INT short
#define __BUFSIZ__ 16
#define _REENT_SMALL
#endif

#if defined __MSP430__
#ifndef _REENT_SMALL
#define _REENT_SMALL
#endif

#define __SMALL_BITFIELDS

#ifdef __MSP430X_LARGE__
#define _POINTER_INT long
#else
#define _POINTER_INT int
#endif
#endif

#ifdef __m32c__
#define __SMALL_BITFIELDS
#undef INT_MAX
#undef UINT_MAX
#define INT_MAX __INT_MAX__
#define UINT_MAX (__INT_MAX__ * 2U + 1)
#define MALLOC_ALIGNMENT 8
#if defined(__r8c_cpu__) || defined(__m16c_cpu__)
#define _POINTER_INT short
#else
#define _POINTER_INT long
#endif
#define __BUFSIZ__ 16
#define _REENT_SMALL
#endif /* __m32c__ */

#ifdef __SPU__
#define MALLOC_ALIGNMENT 16
#define __CUSTOM_FILE_IO__
#endif

#ifdef __XTENSA__
#include <xtensa/config/core-isa.h>
#define MALLOC_ALIGNMENT ((XCHAL_DATA_WIDTH) < 16 ? 16 : (XCHAL_DATA_WIDTH))
/* esp8266-specific: shrink the default fd buffer size */
#define __BUFSIZ__ 128
#ifndef __DYNAMIC_REENT__
#define __DYNAMIC_REENT__
#endif
#ifndef _REENT_SMALL
#define _REENT_SMALL
#endif
#define HAVE_GETOPT
#endif

/* This block should be kept in sync with GCC's limits.h.  The point
   of having these definitions here is to not include limits.h, which
   would pollute the user namespace, while still using types of the
   the correct widths when deciding how to define __int32_t and
   __int64_t.  */
#ifndef __INT_MAX__
# ifdef INT_MAX
#  define __INT_MAX__ INT_MAX
# else
#  define __INT_MAX__ 2147483647
# endif
#endif

#ifndef __LONG_MAX__
# ifdef LONG_MAX
#  define __LONG_MAX__ LONG_MAX
# else
#  if defined (__alpha__) || (defined (__sparc__) && defined(__arch64__)) \
      || defined (__sparcv9)
#   define __LONG_MAX__ 9223372036854775807L
#  else
#   define __LONG_MAX__ 2147483647L
#  endif /* __alpha__ || sparc64 */
# endif
#endif
/* End of block that should be kept in sync with GCC's limits.h.  */

#ifndef _POINTER_INT
#define _POINTER_INT long
#endif

#ifdef __frv__
#define __ATTRIBUTE_IMPURE_PTR__ __attribute__((__section__(".sdata")))
#endif
#undef __RAND_MAX
#if __INT_MAX__ == 32767
#define __RAND_MAX 32767
#else
#define __RAND_MAX 0x7fffffff
#endif

#if defined(__CYGWIN__)
#include <cygwin/config.h>
#if !defined (__STRICT_ANSI__) || (__STDC_VERSION__ >= 199901L)
#define __USE_XOPEN2K 1
#endif
#endif

#if defined(__rtems__)
#define __FILENAME_MAX__ 255
#define _READ_WRITE_RETURN_TYPE _ssize_t
#define __DYNAMIC_REENT__
#define _REENT_GLOBAL_ATEXIT
#endif

#ifndef __EXPORT
#define __EXPORT
#endif

#ifndef __IMPORT
#define __IMPORT
#endif

/* Define return type of read/write routines.  In POSIX, the return type
   for read()/write() is "ssize_t" but legacy newlib code has been using
   "int" for some time.  If not specified, "int" is defaulted.  */
#ifndef _READ_WRITE_RETURN_TYPE
#define _READ_WRITE_RETURN_TYPE int
#endif
/* Define `count' parameter of read/write routines.  In POSIX, the `count'
   parameter is "size_t" but legacy newlib code has been using "int" for some
   time.  If not specified, "int" is defaulted.  */
#ifndef _READ_WRITE_BUFSIZE_TYPE
#define _READ_WRITE_BUFSIZE_TYPE int
#endif

#ifndef __WCHAR_MAX__
#if __INT_MAX__ == 32767 || defined (_WIN32)
#define __WCHAR_MAX__ 0xffffu
#endif
#endif

/* See if small reent asked for at configuration time and
   is not chosen by the platform by default.  */
#ifdef _WANT_REENT_SMALL
#ifndef _REENT_SMALL
#define _REENT_SMALL
#endif
#endif

/* If _MB_EXTENDED_CHARSETS_ALL is set, we want all of the extended
   charsets.  The extended charsets add a few functions and a couple
   of tables of a few K each. */
#ifdef _MB_EXTENDED_CHARSETS_ALL
#define _MB_EXTENDED_CHARSETS_ISO 1
#define _MB_EXTENDED_CHARSETS_WINDOWS 1
#endif

#endif /* __SYS_CONFIG_H__ */