maint: use adaptive approach for `ulimit -v` based tests

When configured with either 'symlinks' or 'shebangs' as value for
the --enable-single-binary option, tests based on `ulimit -v` are
skipped.  The reason is that the multicall 'coreutils' binary requires
much more memory due to shared libraries being loaded, and the size of
the 'date' binary (~290KiB) compared to the multicall binary (~5MiB),
of course.  Finally, in the case of 'shebangs', the starting shell
requires more memory, too

Instead of using hard-coded values for the memory limit, use an
adaptive approach: first determine the amount of memory for a similar,
yet more trivial invocation of the command, and then do the real test
run using that limit (plus some buffer in some cases).

* init.cfg (require_ulimit_v_): Remove function.
(get_min_ulimit_v_): Add function to determine the minimum memory limit
required for a given command in an adaptive way.
* cfg.mk (sc_prohibit_test_ulimit_without_require_): Change the name
of the above function in the syntax-check rule.
* tests/cp/link-heap.sh: Use the above function to determine the
minimum memory required to run a command simpler than in the real test
run.  Use that limit plus a buffer there.  While at it, change to list
of commands in the subshell to fail also if the beginning `ulimit -v`
fails.
* tests/dd/no-allocate.sh: Likewise.
* tests/misc/csplit-heap.sh: Likewise.
* tests/misc/cut-huge-range.sh: Likewise.
* tests/misc/head-c.sh: Likewise.
* tests/misc/printf-surprise.sh: Likewise.
* tests/split/line-bytes.sh: Likewise.
* tests/rm/many-dir-entries-vs-OOM.sh: Likewise - doing it separately
for each program under test.

1 files changed, 19 insertions, 11 deletions

diff --git a/tests/rm/many-dir-entries-vs-OOM.sh b/tests/rm/many-dir-entries-vs-OOM.sh
index e9c95d5d5..8cc839bd1 100755
--- a/tests/rm/many-dir-entries-vs-OOM.sh
+++ b/tests/rm/many-dir-entries-vs-OOM.sh
@@ -19,21 +19,29 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ rm du chmod
-require_ulimit_v_
-
 expensive_
 
+mkdir d2 \
+  && touch d2/f || framework_failure_
+
+# Restrict memory.  Each of these coreutils-8.12 programs would fail
+# with a diagnostic like "rm: fts_read failed: Cannot allocate memory".
+vm=$(get_min_ulimit_v_ du -sh d2) \
+  || skip_ "this shell lacks ulimit support"
+
 # With many files in a single directory...
-mkdir d && cd d || framework_failure_
-seq 200000|xargs touch || framework_failure_
+mkdir d || framework_failure_
+seq --format="d/%06g" 200000 | xargs touch || framework_failure_
 
-cd ..
+# Allow 35MiB more memory as for the trivial case above.
+(ulimit -v $(($vm + 35000)) && du -sh d) || fail=1
 
-# Restricted to 40MB, each of these coreutils-8.12 programs would fail
-# with a diagnostic like "rm: fts_read failed: Cannot allocate memory".
-ulimit -v 40000
-du -sh d || fail=1
-chmod -R 700 d || fail=1
-rm -rf d || fail=1
+vm=$(get_min_ulimit_v_ chmod -R 700 d2) \
+  || skip_ "this shell lacks ulimit support"
+(ulimit -v $(($vm + 35000)) && chmod -R 700 d) || fail=1
+
+vm=$(get_min_ulimit_v_ rm -rf d2) \
+  || skip_ "this shell lacks ulimit support"
+(ulimit -v $(($vm + 35000)) && rm -rf d) || fail=1
 
 Exit $fail