[PATCH] Add multifile-low-mem.sh test-case

[PATCH] Add multifile-low-mem.sh test-case

[Tom de Vries]

Jakub,

When I run dwz in multifile mode for files 1, 2 and 3 with a low-mem-die-limit
low_mem_limit like so:
...
$ dwz -l$low_mem_limit -m 4 1 2 3
...
where the low-mem-die-limit triggers for file 3, I observed that file 3 is
excluded from wr_multifile mode, but is still included in fi_multifile mode.

The documentation in dwz.c states:
...
If some executable or shared library has too large debug information
(number of DIEs in .debug_info section) that there would be
risk of too high memory consumption, that file isn't multifile
optimized, instead it is processed by dwz () in a low-memory mode
with low_mem flag set.
...

My understanding from the documentation is that the behaviour described above
is a bug, but I'm not sure, it might be an intended feature.

So, my question is: is this a bug?

If so, then I can commit the test-case below as is.

If not, then I can commit the test-case below modified to accept the 
  [ "$(gnu-debugaltlink-name.sh 3)" = "4" ]
case as expected behaviour and close PR24274 as resolved-invalid.

Thanks,
- Tom

Add multifile-low-mem.sh test-case

Add test-case that tests behaviour of dwz in multifile mode for files
that trigger the low-mem-die-limit.


2019-03-17  Tom de Vries  <tdevries@suse.de>

	* testsuite/dwz.tests/multifile-low-mem.sh: New test.

---
 testsuite/dwz.tests/multifile-low-mem.sh | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/testsuite/dwz.tests/multifile-low-mem.sh b/testsuite/dwz.tests/multifile-low-mem.sh
new file mode 100644
index 0000000..51345be
--- /dev/null
+++ b/testsuite/dwz.tests/multifile-low-mem.sh
@@ -0,0 +1,25 @@
+cp ../hello 1
+cp ../hello 2
+cp ../dwz-for-test 3
+
+low_mem_limit=$(readelf -w 3 \
+		    | grep '(DW_TAG' \
+		    | wc -l)
+low_mem_limit=$((low_mem_limit - 1))
+
+dwz -l$low_mem_limit -m 4 1 2 3
+
+smaller-than.sh 1 ../hello
+smaller-than.sh 2 ../hello
+smaller-than.sh 3 ../dwz-for-test
+
+[ $(gnu-debugaltlink-name.sh 1) = "4" ]
+[ $(gnu-debugaltlink-name.sh 2) = "4" ]
+
+if [ "$(gnu-debugaltlink-name.sh 3)" = "4" ]; then
+    echo "PR24274 workaround used" > dwz.info
+else
+    [ "$(gnu-debugaltlink-name.sh 3)" = "" ]
+fi
+
+rm -f 1 2 3 4