[PATCH v2] binutils, gdb: support zstd compressed debug sections

[Simon Marchi]

Hi,

Running `autoreconf -vf` in the various subdirectories, I get some
diffs.  Can you run that command in the directories you touch?

> diff --git a/config/zstd.m4 b/config/zstd.m4
> new file mode 100644
> index 00000000000..6495a039f2c
> --- /dev/null
> +++ b/config/zstd.m4
> @@ -0,0 +1,21 @@
> +AC_DEFUN([AM_ZSTD],

This file would need a copyright header.  You could copy the one from
elf.m4, for instance.  Can you also add a one-line comment to explain
what the macro does (check for the zstd library)?

> +[
> +AC_ARG_WITH(zstd,
> +  [AS_HELP_STRING([--with-zstd], [support zstd compressed debug sections (default=auto)])],
> +  [], [with_zstd=auto])
> +AC_MSG_CHECKING([whether to use zstd])
> +AC_MSG_RESULT([$with_zstd])

Ah, I see what you mean by missing AC_MSG_CHECKING and AC_MSG_RESULT.
In my opinion, if the user passes --without-zstd, we don't need to print
a message about zstd.  But whatever we choose, it would be nice to try
to keep consistent.

> +
> +if test "$with_zstd" != no; then
> +  PKG_PROG_PKG_CONFIG
> +  PKG_CHECK_MODULES(ZSTD, [libzstd], [
> +    AC_DEFINE(HAVE_ZSTD, 1, [Define to 1 if zstd is enabled])
> +    AC_SUBST([ZSTD_CFLAGS])
> +    AC_SUBST([ZSTD_LIBS])

I think you don't need these AC_SUBST, PKG_CHECK_MODULES does it for
you.

Simon