[PATCH] Fix GCC 10+ build failure with zstd version 1.2.0 or older.

[Richard Biener]

On Tue, Sep 29, 2020 at 2:46 AM Jim Wilson <jimw@sifive.com> wrote:
>
> Extends the configure check for zstd.h to also verify the zstd version,
> since gcc requires features that only exist in 1.3.0 and newer.  Without
> this patch we get a build error for lto-compress.c when using an old zstd
> version.
>
> Tested with builds using zstd 0.5.1, 1.2.0, 1.3.0, and 1.3.3, and checking
> to see whether zstd was enabled for the build or not.
>
> OK?

OK.

Richard.

> Jim
>
>         gcc/
>         PR 97183
>         * configure.ac (gcc_cv_header_zstd_h): Check ZSTD_VERISON_NUMBER.
>         * configure: Regenerated.
> ---
>  gcc/configure    | 11 ++++++++---
>  gcc/configure.ac |  7 ++++++-
>  2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/configure b/gcc/configure
> index 33a3e34029f..b05a3714fb2 100755
> --- a/gcc/configure
> +++ b/gcc/configure
> @@ -10022,9 +10022,14 @@ $as_echo_n "checking for zstd.h... " >&6; }
>  if ${gcc_cv_header_zstd_h+:} false; then :
>    $as_echo_n "(cached) " >&6
>  else
> -  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +  # We require version 1.3.0 or later.  This is the first version that has
> +# ZSTD_getFrameContentSize.
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
>  /* end confdefs.h.  */
>  #include <zstd.h>
> +#if ZSTD_VERSION_NUMBER < 10300
> +#error "need zstd 1.3.0 or better"
> +#endif
>  int
>  main ()
>  {
> @@ -19013,7 +19018,7 @@ else
>    lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
>    lt_status=$lt_dlunknown
>    cat > conftest.$ac_ext <<_LT_EOF
> -#line 19016 "configure"
> +#line 19021 "configure"
>  #include "confdefs.h"
>
>  #if HAVE_DLFCN_H
> @@ -19119,7 +19124,7 @@ else
>    lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
>    lt_status=$lt_dlunknown
>    cat > conftest.$ac_ext <<_LT_EOF
> -#line 19122 "configure"
> +#line 19127 "configure"
>  #include "confdefs.h"
>
>  #if HAVE_DLFCN_H
> diff --git a/gcc/configure.ac b/gcc/configure.ac
> index 975f6d97c4b..f5612161dcd 100644
> --- a/gcc/configure.ac
> +++ b/gcc/configure.ac
> @@ -1376,8 +1376,13 @@ LDFLAGS="$LDFLAGS $ZSTD_LDFLAGS"
>
>  AC_MSG_CHECKING(for zstd.h)
>  AC_CACHE_VAL(gcc_cv_header_zstd_h,
> +# We require version 1.3.0 or later.  This is the first version that has
> +# ZSTD_getFrameContentSize.
>  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
> -[[#include <zstd.h>]])],
> +[[#include <zstd.h>
> +#if ZSTD_VERSION_NUMBER < 10300
> +#error "need zstd 1.3.0 or better"
> +#endif]])],
>    [gcc_cv_header_zstd_h=yes],
>    [gcc_cv_header_zstd_h=no])])
>  AC_MSG_RESULT($gcc_cv_header_zstd_h)
> --
> 2.17.1
>