cdefs.h 6.7 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216
  1. /* Copyright (C) 1992,93,94,95,96,97,98,99,2000,2001,2002 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. #ifndef _SYS_CDEFS_H
  16. #define _SYS_CDEFS_H 1
  17. /* We are almost always included from features.h. */
  18. #ifndef _FEATURES_H
  19. # include <features.h>
  20. #endif
  21. /* The GNU libc does not support any K&R compilers or the traditional mode
  22. of ISO C compilers anymore. Check for some of the combinations not
  23. anymore supported. */
  24. #if defined __GNUC__ && !defined __STDC__
  25. # error "You need a ISO C conforming compiler to use the glibc headers"
  26. #endif
  27. /* Some user header file might have defined this before. */
  28. #undef __P
  29. #undef __PMT
  30. #ifdef __GNUC__
  31. /* GCC can always grok prototypes. For C++ programs we add throw()
  32. to help it optimize the function calls. But this works only with
  33. gcc 2.8.x and egcs. */
  34. # if defined __cplusplus && __GNUC_PREREQ (2,8)
  35. # define __THROW throw ()
  36. # else
  37. # define __THROW
  38. # endif
  39. # define __P(args) args __THROW
  40. /* This macro will be used for functions which might take C++ callback
  41. functions. */
  42. # define __PMT(args) args
  43. #else /* Not GCC. */
  44. # define __inline /* No inline functions. */
  45. # define __THROW
  46. # define __P(args) args
  47. # define __PMT(args) args
  48. # define __const const
  49. # define __signed signed
  50. # define __volatile volatile
  51. #endif /* GCC. */
  52. /* For these things, GCC behaves the ANSI way normally,
  53. and the non-ANSI way under -traditional. */
  54. #define __CONCAT(x,y) x ## y
  55. #define __STRING(x) #x
  56. /* This is not a typedef so `const __ptr_t' does the right thing. */
  57. #define __ptr_t void *
  58. #define __long_double_t long double
  59. /* C++ needs to know that types and declarations are C, not C++. */
  60. #ifdef __cplusplus
  61. # define __BEGIN_DECLS extern "C" {
  62. # define __END_DECLS }
  63. #else
  64. # define __BEGIN_DECLS
  65. # define __END_DECLS
  66. #endif
  67. /* Support for bounded pointers. */
  68. #ifndef __BOUNDED_POINTERS__
  69. # define __bounded /* nothing */
  70. # define __unbounded /* nothing */
  71. # define __ptrvalue /* nothing */
  72. #endif
  73. /* Support for flexible arrays. */
  74. #if __GNUC_PREREQ (2,97)
  75. /* GCC 2.97 supports C99 flexible array members. */
  76. # define __flexarr []
  77. #else
  78. # ifdef __GNUC__
  79. # define __flexarr [0]
  80. # else
  81. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  82. # define __flexarr []
  83. # else
  84. /* Some other non-C99 compiler. Approximate with [1]. */
  85. # define __flexarr [1]
  86. # endif
  87. # endif
  88. #endif
  89. /* __asm__ ("xyz") is used throughout the headers to rename functions
  90. at the assembly language level. This is wrapped by the __REDIRECT
  91. macro, in order to support compilers that can do this some other
  92. way. When compilers don't support asm-names at all, we have to do
  93. preprocessor tricks instead (which don't have exactly the right
  94. semantics, but it's the best we can do).
  95. Example:
  96. int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
  97. #if defined __GNUC__ && __GNUC__ >= 2
  98. # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
  99. # define __ASMNAME(cname) C_SYMBOL_PREFIX cname
  100. /*
  101. #elif __SOME_OTHER_COMPILER__
  102. # define __REDIRECT(name, proto, alias) name proto; \
  103. _Pragma("let " #name " = " #alias)
  104. */
  105. #endif
  106. /* GCC has various useful declarations that can be made with the
  107. `__attribute__' syntax. All of the ways we use this do fine if
  108. they are omitted for compilers that don't understand it. */
  109. #if !defined __GNUC__ || __GNUC__ < 2
  110. # define __attribute__(xyz) /* Ignore */
  111. #endif
  112. /* At some point during the gcc 2.96 development the `malloc' attribute
  113. for functions was introduced. We don't want to use it unconditionally
  114. (although this would be possible) since it generates warnings. */
  115. #if __GNUC_PREREQ (2,96)
  116. # define __attribute_malloc__ __attribute__ ((__malloc__))
  117. #else
  118. # define __attribute_malloc__ /* Ignore */
  119. #endif
  120. /* At some point during the gcc 2.96 development the `pure' attribute
  121. for functions was introduced. We don't want to use it unconditionally
  122. (although this would be possible) since it generates warnings. */
  123. #if __GNUC_PREREQ (2,96)
  124. # define __attribute_pure__ __attribute__ ((__pure__))
  125. #else
  126. # define __attribute_pure__ /* Ignore */
  127. #endif
  128. /* At some point during the gcc 2.8 development the `format_arg' attribute
  129. for functions was introduced. We don't want to use it unconditionally
  130. (although this would be possible) since it generates warnings.
  131. If several `format_arg' attributes are given for the same function, in
  132. gcc-3.0 and older, all but the last one are ignored. In newer gccs,
  133. all designated arguments are considered. */
  134. #if __GNUC_PREREQ (2,8)
  135. # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
  136. #else
  137. # define __attribute_format_arg__(x) /* Ignore */
  138. #endif
  139. /* At some point during the gcc 2.97 development the `strfmon' format
  140. attribute for functions was introduced. We don't want to use it
  141. unconditionally (although this would be possible) since it
  142. generates warnings. */
  143. #if __GNUC_PREREQ (2,97)
  144. # define __attribute_format_strfmon__(a,b) \
  145. __attribute__ ((__format__ (__strfmon__, a, b)))
  146. #else
  147. # define __attribute_format_strfmon__(a,b) /* Ignore */
  148. #endif
  149. /* It is possible to compile containing GCC extensions even if GCC is
  150. run in pedantic mode if the uses are carefully marked using the
  151. `__extension__' keyword. But this is not generally available before
  152. version 2.8. */
  153. #if !__GNUC_PREREQ (2,8)
  154. # define __extension__ /* Ignore */
  155. #endif
  156. /* __restrict is known in EGCS 1.2 and above. */
  157. #if !__GNUC_PREREQ (2,92)
  158. # define __restrict /* Ignore */
  159. #endif
  160. /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
  161. array_name[restrict]
  162. GCC 3.1 supports this. */
  163. #if __GNUC_PREREQ (3,1) && !defined __GNUG__
  164. # define __restrict_arr __restrict
  165. #else
  166. # ifdef __GNUC__
  167. # define __restrict_arr /* Not supported in old GCC. */
  168. # else
  169. # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
  170. # define __restrict_arr restrict
  171. # else
  172. /* Some other non-C99 compiler. */
  173. # define __restrict_arr /* Not supported. */
  174. # endif
  175. # endif
  176. #endif
  177. #endif /* sys/cdefs.h */