AS_HELP_STRING多行

Question

是否有办法将AS_HELP_STRING（或其他宏）转换为多行nicely格式帮助？

我有一个--enable-option=，它可以采用多个值val1,val2,...，我希望configure --help为每个值显示一个帮助行。

Answer 1

我为这种情况编写了自己的NA_HELP_STRINGS()宏：

dnl  NA_HELP_STRINGS(list1, help1[, list2, help2[, ... listN, helpN]])
dnl  **************************************************************************
dnl
dnl  Similar to `AS_HELP_STRING()`, but with support for multiple strings, each
dnl  one associated with one or more options
dnl
dnl  From: https://github.com/madmurphy/not-autotools
dnl
dnl  **************************************************************************
m4_define([NA_HELP_STRINGS],
    [m4_if(m4_count($1), [1],
        [m4_if([$#], [0], [], [$#], [1],
            [m4_text_wrap($1, [  ])],
            [AS_HELP_STRING(m4_normalize($1), [$2])m4_if([$#], [2], [], [m4_newline()NA_HELP_STRINGS(m4_shift2($@))])])],
        [m4_text_wrap(m4_argn(1, $1)[,], [  ])m4_newline()NA_HELP_STRINGS(m4_dquote(m4_shift($1))m4_if([$#], [1], [], [, m4_shift($@)]))])])

示例用法：

AC_ARG_ENABLE([foo],
    [NA_HELP_STRINGS(
        [--disable-foo],
            [disable the `foo` feature; on some machines the package might not
            work properly without the `foo` feature enabled],
        [[--enable-foo], [--enable-foo=yes], [--enable-foo=enhanced]],
            [install this package with the `foo` feature enabled; if `foo` is
            enabled in `enhanced` mode Autoconf might get sentimental],
        [[--enable-foo=auto], [--enable-foo=check], [@<:@omitted@:>@]],
            [decide automatically whether it is opportune to enable the `foo`
            feature on this machine or not]
    )],
    [:],
    [AS_VAR_SET([enable_foo], ['check'])])

用户启动./configure --help时的输出：

  --disable-foo           disable the `foo` feature; on some machines the
                          package might not work properly without the `foo`
                          feature enabled
  --enable-foo,
  --enable-foo=yes,
  --enable-foo=enhanced   install this package with the `foo` feature enabled;
                          if `foo` is enabled in `enhanced` mode Autoconf
                          might get sentimental
  --enable-foo=auto,
  --enable-foo=check,
  [omitted]               decide automatically whether it is opportune to
                          enable the `foo` feature on this machine or not

有关更多m4-ish示例，请查看Not Autotools项目。