# KNOT_CHECK_HEADER([prefix], [name], [default], [header], [cflags], [libs]) # ----------------------------------------------------------------------------- # Check presence of a library by checking for a header file. # # - adds --enable-prefix configure flag # # - if $enable_prefix is yes or auto, checks for the header file # # - emits an error if $enable_prefix is yes and the header is not present # # - check can be overridden by setting prefix_CFLAGS and prefix_LIBS # environment variables # # Output variables: $enable_foo (yes or no), $foo_CFLAGS, and $foo_LIBS # AC_DEFUN([KNOT_CHECK_HEADER], [ AC_ARG_ENABLE([$1], AC_HELP_STRING([--enable-$1], [Support for $2 [default $3]]), [enable_][$1][=$enableval], [enable_][$1][=][$3]) AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $2, overriding defaults]) AC_ARG_VAR([$1][_LIBS], [linker flags for $2, overriding defaults]) AS_CASE([$enable_][$1], [no], [ [$1][_CFLAGS]= [$1][_LIBS]= ], [auto|yes], [ AS_IF([test -n "$][$1][_LIBS"], [ dnl: skip header check if environment variable is set [enable_][$1][=yes] ],[ dnl: check for header AC_CHECK_HEADER([$4], [ [enable_][$1]=yes [$1][_CFLAGS]=[$5] [$1][_LIBS]=[$6] ], [ AS_IF([test "$enable_][$1][" = auto], [[enable_][$1]=no], [AC_MSG_ERROR([Header file "$4" for $2 not found])] ) ]) ]) ], [AC_MSG_ERROR([Invalid value of --enable-$1])] ) ])