tests: diff -u is not portable

Reported by Didier Godefroy
<http://lists.gnu.org/archive/html/bug-bison/2012-10/msg00006.html>.

* tests/existing.at (AT_LALR1_DIFF_CHECK): Skip if diff -u does not
work.

diff --git a/NEWS b/NEWS
index c1ab7aa..c8a4d31 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -4,7 +4,7 @@ GNU Bison NEWS
 
 ** Bug fixes
 
-  Bugs in the test suite have been fixed.
+  Bugs and portability issues in the test suite have been fixed.
 
   Some errors in translations have been addressed, and --help now directs
   users to the appropriate place to report them.

diff --git a/tests/existing.at b/tests/existing.at
index 582f6b3..149499d 100644 (file)
--- a/tests/existing.at
+++ b/tests/existing.at
@@ -35,7 +35,10 @@ dnl time comes, just use sed to drop the line numbers.  For now, as LR(1)
 dnl support is rapidly evolving, let's keep that information to be careful.
 dnl However, we don't do diffs for canonical LR(1) because the diff is huge.
 m4_pushdef([AT_LALR1_DIFF_CHECK],
-[AT_CHECK([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
+[dnl We need diff -u, which is not portable.
+AT_CHECK([diff -u /dev/null /dev/null || exit 77], [0], [ignore])
+
+AT_CHECK([[sed 's/^%define lr.type .*$//' input.y > input-lalr.y]])
 AT_BISON_CHECK([[--report=all input-lalr.y]], [[0]], [ignore], [ignore])
 AT_CHECK([[diff -u input-lalr.output input.output \
            | sed -n '/^@@/,$p' | sed 's/^ $//']],