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_ac_c_ifdef

Synopsis

_AC_C_IFDEF(MACRO-NAME, ACTION-IF-DEF, ACTION-IF-NOT-DEF)

Description

Check for the definition of macro MACRO-NAME using the current language's compiler.

Version

20040907

Author

Ludovic Courtès <ludo@chbouib.org>

M4 Source Code

AC_DEFUN([_AC_C_IFDEF],
  [AC_COMPILE_IFELSE([#ifndef $1
                      # error "Macro $1 is undefined!"
                      /* For some compilers (eg. SGI's CC), #error is not
                         enough...  */
                      please, do fail
                      #endif],
                     [$2], [$3])])

Copyright

GNU General Public License with this special exception.