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.

8 files changed, 61 insertions, 33 deletions

diff --git a/tests/cp/link-heap.sh b/tests/cp/link-heap.sh
index 901a92fc7..b65223a59 100755
--- a/tests/cp/link-heap.sh
+++ b/tests/cp/link-heap.sh
@@ -19,7 +19,12 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ cp
 expensive_
-require_ulimit_v_
+
+# Determine basic amount of memory needed for 'cp -al'.
+touch f || framework_failure_
+vm=$(get_min_ulimit_v_ cp -al f f2) \
+  || skip_ "this shell lacks ulimit support"
+rm f f2 || framework_failure_
 
 a=$(printf %031d 0)
 b=$(printf %031d 1)
@@ -31,7 +36,7 @@ cp -al $a $b || framework_failure_
 mkdir e || framework_failure_
 mv $a $b e || framework_failure_
 
-# Increased from 20000 to 22000 in 2012, for pre-F18 rawhide.
-(ulimit -v 22000; cp -al e f) || fail=1
+# Allow cp(1) to use 4MiB more virtual memory than for the above trivial case.
+(ulimit -v $(($vm+4000)) && cp -al e f) || fail=1
 
 Exit $fail
diff --git a/tests/dd/no-allocate.sh b/tests/dd/no-allocate.sh
index 99e0542ac..d122e3544 100755
--- a/tests/dd/no-allocate.sh
+++ b/tests/dd/no-allocate.sh
@@ -18,12 +18,17 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ dd
-require_ulimit_v_
+
+# Determine basic amount of memory needed.
+echo . > f || framework_failure_
+vm=$(get_min_ulimit_v_ dd if=f of=f2 status=none) \
+  || skip_ "this shell lacks ulimit support"
+rm -f f || framework_failure_
 
 # count and skip are zero, we don't need to allocate memory
-(ulimit -v 20000; dd  bs=30M count=0) || fail=1
-(ulimit -v 20000; dd ibs=30M count=0) || fail=1
-(ulimit -v 20000; dd obs=30M count=0) || fail=1
+(ulimit -v $vm && dd  bs=30M count=0) || fail=1
+(ulimit -v $vm && dd ibs=30M count=0) || fail=1
+(ulimit -v $vm && dd obs=30M count=0) || fail=1
 
 check_dd_seek_alloc() {
   local file="$1"
@@ -38,7 +43,8 @@ check_dd_seek_alloc() {
   timeout 10 dd count=1 if=/dev/zero of=tape&
 
   # Allocate buffer and read from the "tape"
-  (ulimit -v 20000; timeout 10 dd $dd_buf=30M $dd_op=1 count=0 $dd_file=tape)
+  (ulimit -v $(($vm+4000)) \
+    && timeout 10 dd $dd_buf=30M $dd_op=1 count=0 $dd_file=tape)
   local ret=$?
 
   # Be defensive in case the tape reader is blocked for some reason
diff --git a/tests/misc/csplit-heap.sh b/tests/misc/csplit-heap.sh
index 9e51cb15f..0ffe70ad4 100755
--- a/tests/misc/csplit-heap.sh
+++ b/tests/misc/csplit-heap.sh
@@ -19,11 +19,14 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ csplit
 
-require_ulimit_v_
+# Determine basic amount of memory needed.
+{ echo y; echo n; } > f || framework_failure_
+vm=$(get_min_ulimit_v_ csplit -z f %n%1) \
+  || skip_ "this shell lacks ulimit support"
 
 (
- ulimit -v 20000
- { yes | head -n2500000; echo n; } | csplit -z - %n%1
+ ulimit -v $vm \
+   && { yes | head -n2500000; echo n; } | csplit -z - %n%1
 ) || fail=1
 
 Exit $fail
diff --git a/tests/misc/cut-huge-range.sh b/tests/misc/cut-huge-range.sh
index 035d8d087..4df2fc066 100755
--- a/tests/misc/cut-huge-range.sh
+++ b/tests/misc/cut-huge-range.sh
@@ -18,9 +18,11 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ cut
-require_ulimit_v_
 getlimits_
 
+vm=$(get_min_ulimit_v_ cut -b1 /dev/null) \
+  || skip_ "this shell lacks ulimit support"
+
 # sed script to subtract one from the input.
 # Each input line should consist of a positive decimal number.
 # Each output line's number is one less than the input's.
@@ -49,15 +51,15 @@ CUT_MAX=$(echo $SIZE_MAX | sed "$subtract_one")
 
 # From coreutils-8.10 through 8.20, this would make cut try to allocate
 # a 256MiB bit vector.  With a 20MB limit on VM, the following would fail.
-(ulimit -v 20000; : | cut -b$CUT_MAX- > err 2>&1) || fail=1
+(ulimit -v $vm && : | cut -b$CUT_MAX- > err 2>&1) || fail=1
 
 # Up to and including coreutils-8.21, cut would allocate possibly needed
 # memory upfront.  Subsequently extra memory is no longer needed.
-(ulimit -v 20000; : | cut -b1-$CUT_MAX >> err 2>&1) || fail=1
+(ulimit -v $vm && : | cut -b1-$CUT_MAX >> err 2>&1) || fail=1
 
 # Explicitly disallow values above CUT_MAX
-(ulimit -v 20000; : | returns_ 1 cut -b$SIZE_MAX 2>/dev/null) || fail=1
-(ulimit -v 20000; : | returns_ 1 cut -b$SIZE_OFLOW 2>/dev/null) || fail=1
+(ulimit -v $vm && : | returns_ 1 cut -b$SIZE_MAX 2>/dev/null) || fail=1
+(ulimit -v $vm && : | returns_ 1 cut -b$SIZE_OFLOW 2>/dev/null) || fail=1
 
 compare /dev/null err || fail=1
 
diff --git a/tests/misc/head-c.sh b/tests/misc/head-c.sh
index a553a55bc..ab821ac61 100755
--- a/tests/misc/head-c.sh
+++ b/tests/misc/head-c.sh
@@ -18,9 +18,11 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ head
-require_ulimit_v_
 getlimits_
 
+vm=$(get_min_ulimit_v_ head -c1 /dev/null) \
+  || skip_ "this shell lacks ulimit support"
+
 # exercise the fix of 2001-08-18, based on test case from Ian Bruce
 echo abc > in || framework_failure_
 (head -c1; head -c1) < in > out || fail=1
@@ -40,7 +42,7 @@ esac
 # Only allocate memory as needed.
 # Coreutils <= 8.21 would allocate memory up front
 # based on the value passed to -c
-(ulimit -v 20000; head --bytes=-$SSIZE_MAX < /dev/null) || fail=1
+(ulimit -v $vm && head --bytes=-$SSIZE_MAX < /dev/null) || fail=1
 
 # Make sure it works on funny files in /proc and /sys.
 
diff --git a/tests/misc/printf-surprise.sh b/tests/misc/printf-surprise.sh
index 20e6b0988..8480693fc 100755
--- a/tests/misc/printf-surprise.sh
+++ b/tests/misc/printf-surprise.sh
@@ -20,8 +20,9 @@ prog=printf
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ printf
-require_ulimit_v_
 
+vm=$(get_min_ulimit_v_ env $prog %20f 0) \
+  || skip_ "this shell lacks ulimit support"
 
 # Up to coreutils-6.9, "printf %.Nf 0" would encounter an ENOMEM internal
 # error from glibc's printf(3) function whenever N was large relative to
@@ -60,7 +61,7 @@ head -c 10 fifo > out & pid=$!
 
 # Choosing the virtual memory limit, 11000 is enough, but 10000 is too
 # little and provokes a "memory exhausted" diagnostic on FreeBSD 9.0-p3.
-( ulimit -v 15000; env $prog %20000000f 0 2>err-msg > fifo )
+( ulimit -v $vm && env $prog %20000000f 0 2>err-msg > fifo )
 exit=$?
 
 # Map this longer, and rarer, diagnostic to the common one.
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
diff --git a/tests/split/line-bytes.sh b/tests/split/line-bytes.sh
index 6e2f13765..f2f0f8fd0 100755
--- a/tests/split/line-bytes.sh
+++ b/tests/split/line-bytes.sh
@@ -18,11 +18,12 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ split
-require_ulimit_v_
 
+vm=$(get_min_ulimit_v_ split -C 'K' /dev/null) \
+  || skip_ "this shell lacks ulimit support"
 
 # Ensure memory is not allocated up front
-(ulimit -v 20000; split -C 'G' /dev/null) || fail=1
+(ulimit -v $vm && split -C 'G' /dev/null) || fail=1
 
 
 # Ensure correct operation with various split and buffer size combinations