[m-rev.] for review: support editline as an alternative to GNU readline

[Mark Brown]

Hi Julien,

On Mon, Jun 18, 2018 at 4:22 PM, Julien Fischer <jfischer at opturion.com> wrote:
>
> For review by anyone.
>
> -------------------------------
>
> Support editline as an alternative to GNU readline.
>
> Support the use of the editline library as an alternative to GNU readline
> for
> the debugger command-line prompt.  The former has a more permissive license
> than the latter.  If licensing is not an issue then GNU readline is the
> preferable choice (e.g. feature wise), as such it is the default option.

s/,/;/

>
> NOTE: there are (apparently) two editline libraries, one derived from NetBSD
> and one from Minix -- this diff adds support for the former.  (Using the
> latter should just be a matter of using a different header file and
> supplying a different library name to link against, but I haven't tried
> it yet.)
>
> m4/mercury.m4:
>     Add a configuration check for editline library
>
> configure.ac:
>     Check for the presence of editline library.
>
> runtime/mercury_conf.h.in:
>     Replace the macro MR_NO_USE_READLINE with MR_USE_READLINE which
>     is defined if GNU readline is available and the user has not
>     forbidden its use.
>
>     Add a new macro MR_USE_EDITLINE which does the same for editline.
>
>     Add a new macro that is defined if the header editline/readline.h
>     is present.
>
> trace/mercury_trace_completion.c:
> trace/mercury_trace_readline.c:
>     Use editline in place of readline if appropriate.
>
> Julien.
>
> diff --git a/configure.ac b/configure.ac
> index 37ee475..2d295f4 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -5227,10 +5227,11 @@ AC_SUBST(USE_MSVCRT)
>
>
> #-----------------------------------------------------------------------------#
>  #
> -# Check for readline
> +# Check for readline and editline.
>  #
>
>  MERCURY_CHECK_READLINE
> +MERCURY_CHECK_EDITLINE
>
>
> #-----------------------------------------------------------------------------#
>  #
> diff --git a/m4/mercury.m4 b/m4/mercury.m4
> index 17c47aa..f83dc56 100644
> --- a/m4/mercury.m4
> +++ b/m4/mercury.m4
> @@ -201,22 +201,22 @@ AC_DEFUN([MERCURY_TRY_STATIC_ASSERT], [
>  AC_DEFUN([MERCURY_CHECK_READLINE],
>  [
>  AC_ARG_WITH(readline,
> -[  --without-readline      Don't use the GPL'd GNU readline library],
> +[  --without-readline      Do not use the GPL'd GNU readline library],
>  mercury_cv_with_readline="$withval", mercury_cv_with_readline=yes)
>
>  if test "$mercury_cv_with_readline" = yes; then
>
> -       # check for the readline header files
> +       # Check for the readline header files.
>         MERCURY_CHECK_FOR_HEADERS(readline/readline.h readline/history.h)
>
> -       # check for the libraries that readline depends on
> +       # Check for the libraries that readline depends on.
>         MERCURY_MSG('looking for termcap or curses (needed by readline)...')
>         AC_CHECK_LIB(termcap, tgetent, mercury_cv_termcap_lib=-ltermcap,
>          [AC_CHECK_LIB(curses,  tgetent, mercury_cv_termcap_lib=-lcurses,
>           [AC_CHECK_LIB(ncurses, tgetent, mercury_cv_termcap_lib=-lncurses,
>            mercury_cv_termcap_lib='')])])
>
> -       # check for the readline library
> +       # Check for the readline library.
>         AC_CHECK_LIB(readline, readline, mercury_cv_have_readline=yes,
>                 mercury_cv_have_readline=no, $mercury_cv_termcap_lib)
>  else
> @@ -230,8 +230,8 @@ fi
>  if test $mercury_cv_have_readline = no; then
>         TERMCAP_LIBRARY=""
>         READLINE_LIBRARIES=""
> -       AC_DEFINE(MR_NO_USE_READLINE)
>  else
> +       AC_DEFINE(MR_USE_READLINE)
>         TERMCAP_LIBRARY="$mercury_cv_termcap_lib"
>         READLINE_LIBRARIES="-lreadline $TERMCAP_LIBRARY"
>  fi
> @@ -241,6 +241,36 @@ AC_SUBST(READLINE_LIBRARIES)
>  ])
>
>
> #-----------------------------------------------------------------------------#
> +
> +AC_DEFUN([MERCURY_CHECK_EDITLINE], [
> +AC_REQUIRE([MERCURY_CHECK_READLINE])
> +AC_ARG_WITH(editline,
> +[  --without-editline      Do not use the editline library],
> +mercury_cv_with_editline="$withval", mercury_cv_with_editline=yes)
> +
> +if test $mercury_cv_with_editline = no; then
> +       mercury_cv_have_editline=no
> +elif test $mercury_cv_have_readline = no; then
> +
> +       # Check for the editline header files.
> +       MERCURY_CHECK_FOR_HEADERS(editline/readline.h)
> +
> +       # Check for the editline library.
> +       AC_CHECK_LIB(edit, readline, mercury_cv_have_editline=yes,
> +               mercury_cv_have_editline=no)
> +else
> +       mercury_cv_have_editline=no
> +fi
> +
> +if test $mercury_cv_have_editline = yes; then
> +       AC_DEFINE(MR_USE_EDITLINE)
> +       TERMCAP_LIBARARIES=""
> +       READLINE_LIBRARIES="-ledit"
> +fi

TERMCAP_LIBRARY

Does it matter that the AC_SUBST for these variables has already happened?

> +
> +])
> +
> +#-----------------------------------------------------------------------------#
>  #
>  # Microsoft.NET configuration
>  #
> diff --git a/runtime/mercury_conf.h.in b/runtime/mercury_conf.h.in
> index 70b26e5..46fc4e5 100644
> --- a/runtime/mercury_conf.h.in
> +++ b/runtime/mercury_conf.h.in
> @@ -533,11 +533,11 @@
>
>  #undef  MR_DEEP_PROFILER_ENABLED
>
> -// MR_NO_USE_READLINE
> +// MR_USE_READLINE
>  //
> -// Set this if you want to prevent the debugger from using the GNU readline
> -// library for the command-line prompt. The autoconfiguration script sets
> this
> -// if it can't find a termcap library.
> +// GNU readline and any supporting libraries required (e.g. termcap) are
> +// available and should be used by the debugger for the command-line
> prompt.
> +// this will *not* be defind if MR_USE_EDITLINE is defined.
>  //
>  // MR_HAVE_READLINE_READLINE_H
>  // MR_HAVE_READLINE_HISTORY_H
> @@ -545,10 +545,23 @@
>  // Defined if the header files readline/readline.h and
>  // readline/history.h are available.
>
> -#undef  MR_NO_USE_READLINE
> +#undef  MR_USE_READLINE
>  #undef  MR_HAVE_READLINE_READLINE_H
>  #undef  MR_HAVE_READLINE_HISTORY_H
>
> +// MR_USE_EDITLINE
> +//
> +// The editline library is available and should be used by the debugger
> +// for the command-line prompt.
> +// This will *not* be defined if MR_USE_READLINE is defined.
> +//
> +// MR_HAVE_EDITLINE_READLINE_H
> +//
> +// Define if the header file editline/readline.h. is available.
> +
> +#undef MR_USE_EDITLINE
> +#undef MR_HAVE_EDITLINE_READLINE_H
> +
>  // MR_MKFIFO
>  //
>  // The name of the shell command to make a named pipe. This will be the
> diff --git a/trace/mercury_trace_completion.c
> b/trace/mercury_trace_completion.c
> index 428b2b1..541c26b 100644
> --- a/trace/mercury_trace_completion.c
> +++ b/trace/mercury_trace_completion.c
> @@ -22,9 +22,11 @@
>  #include <stdlib.h>
>  #include <string.h>
>
> -#ifndef MR_NO_USE_READLINE
> -  #ifdef MR_HAVE_READLINE_READLINE_H
> +#if defined(MR_USE_READLINE) || defined(MR_USE_EDITLINE)
> +  #if defined(MR_HAVE_READLINE_H)

MR_HAVE_READLINE_READLINE_H

>      #include <readline/readline.h>
> +  #elif defined(MR_HAVE_EDITLINE_H)

MR_HAVE_EDITLINE_READLINE_H

The rest looks good to me.

Mark