[gcc(refs/users/rguenth/heads/slp-reorg)] Do not error about missing zstd unless --with-zstd.

[Richard Biener]

https://gcc.gnu.org/g:68c4570a4dea8ed6fefaea50943fb74ea8f78319

commit 68c4570a4dea8ed6fefaea50943fb74ea8f78319
Author: Martin Liska <mliska@suse.cz>
Date:   Wed Mar 25 13:34:53 2020 +0100

    Do not error about missing zstd unless --with-zstd.
    
            PR lto/94259
            * configure.ac: Report error only when --with-zstd
            is used.
            * configure: Regenerate.

Diff:
---
 gcc/ChangeLog    | 7 +++++++
 gcc/configure    | 2 +-
 gcc/configure.ac | 2 +-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b2743d65a37..baf0ab727f3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-25  Martin Liska  <mliska@suse.cz>
+
+	PR lto/94259
+	* configure.ac: Report error only when --with-zstd
+	is used.
+	* configure: Regenerate.
+
 2020-03-25  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/94308
diff --git a/gcc/configure b/gcc/configure
index b4231fe7b7e..dfdc5d8f75a 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -10019,7 +10019,7 @@ if test $gcc_cv_header_zstd_h = yes; then
 
 $as_echo "#define HAVE_ZSTD_H 1" >>confdefs.h
 
-else
+elif test "x$with_zstd" != x; then
     as_fn_error $? "Unable to find zstd.h.  See config.log for details." "$LINENO" 5
 fi
 
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 0051963c85d..fdee9ea587c 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1371,7 +1371,7 @@ AC_MSG_RESULT($gcc_cv_header_zstd_h)
 if test $gcc_cv_header_zstd_h = yes; then
   AC_DEFINE(HAVE_ZSTD_H, 1,
 	[Define if you have a working <zstd.h> header file.])
-else
+elif test "x$with_zstd" != x; then
     as_fn_error $? "Unable to find zstd.h.  See config.log for details." "$LINENO" 5
 fi