m4/inline.m4

   1 # inline.m4 serial 4
   2 dnl Copyright (C) 2006, 2009-2014 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 dnl Test for the 'inline' keyword or equivalent.
   8 dnl Define 'inline' to a supported equivalent, or to nothing if not supported,
   9 dnl like AC_C_INLINE does.  Also, define HAVE_INLINE if 'inline' or an
  10 dnl equivalent is effectively supported, i.e. if the compiler is likely to
  11 dnl drop unused 'static inline' functions.
  12 AC_DEFUN([gl_INLINE],
  13 [
  14   AC_REQUIRE([AC_C_INLINE])
  15   AC_CACHE_CHECK([whether the compiler generally respects inline],
  16     [gl_cv_c_inline_effective],
  17     [if test $ac_cv_c_inline = no; then
  18        gl_cv_c_inline_effective=no
  19      else
  20        dnl GCC defines __NO_INLINE__ if not optimizing or if -fno-inline is
  21        dnl specified.
  22        dnl Use AC_COMPILE_IFELSE here, not AC_EGREP_CPP, because the result
  23        dnl depends on optimization flags, which can be in CFLAGS.
  24        dnl (AC_EGREP_CPP looks only at the CPPFLAGS.)
  25        AC_COMPILE_IFELSE(
  26          [AC_LANG_PROGRAM([[]],
  27            [[#ifdef __NO_INLINE__
  28                #error "inline is not effective"
  29              #endif]])],
  30          [gl_cv_c_inline_effective=yes],
  31          [gl_cv_c_inline_effective=no])
  32      fi
  33     ])
  34   if test $gl_cv_c_inline_effective = yes; then
  35     AC_DEFINE([HAVE_INLINE], [1],
  36       [Define to 1 if the compiler supports one of the keywords
  37        'inline', '__inline__', '__inline' and effectively inlines
  38        functions marked as such.])
  39   fi
  40 ])