Re: [Qemu-devel] [PATCH] tests: Handle $RANDOM not being supported by the shell

[Kamil Rytarowski]

On 14.07.2017 13:27, Kamil Rytarowski wrote:
> On 14.07.2017 12:45, Peter Maydell wrote:
>> In various places in our test makefiles and scripts we use the
>> shell $RANDOM to create a random number. This is a bash
>> specific extension, and doesn't work on other shells.
> 
> This is supported on other shells like ksh (Korn Shell), but still as an
> extension.
> 
>> With dash the shell doesn't complain, it just effectively
>> always evaluates $RANDOM to 0:
>>   echo $((RANDOM + 32768))     => 32768
>>
>> However, on NetBSD the shell will complain:
>>   "-sh: arith: syntax error: "RANDOM + 32768"
>>
> 
> I will make sure whether this behavior is correct in our sh(1).
> 

This has been altered in NetBSD-current (+ 8.0BETA), sh(1) behaves like
dash.

>> which means that "make check" fails.
>>
>> Switch to using "${RANDOM:-0}" instead of $RANDOM,
>> which will portably either give us a random number or zero.
>> This means that on non-bash shells we don't get such
>> good test coverage via the MALLOC_PERTURB_ setting, but
>> we were already in that situation for non-bash shells.
>>
>> Our only other uses of $RANDOM (in tests/qemu-iotests/check
>> and tests/qemu-iotests/162) are in shell scripts which use
>> a #!/bin/bash line so they are always run under bash.
>>
>> Suggested-by: Eric Blake <address@hidden>
>> Signed-off-by: Peter Maydell <address@hidden>
> 
> Reviewed-by: Kamil Rytarowski <address@hidden>
> 
>> ---
>>  tests/Makefile.include | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>> index 6d6cb74..f6310d2 100644
>> --- a/tests/Makefile.include
>> +++ b/tests/Makefile.include
>> @@ -826,7 +826,7 @@ $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): 
>> check-qtest-%: $(check-qtest-y)
>>      $(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
>>      $(call quiet-command,QTEST_QEMU_BINARY=$*-softmmu/qemu-system-$* \
>>              QTEST_QEMU_IMG=qemu-img$(EXESUF) \
>> -            MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$((RANDOM % 255 + 1))} \
>> +            MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(( $${RANDOM:-0} % 255 + 
>> 1))} \
>>              gtester $(GTESTER_OPTIONS) -m=$(SPEED) $(check-qtest-$*-y) 
>> $(check-qtest-generic-y),"GTESTER","$@")
>>      $(if $(CONFIG_GCOV),@for f in $(gcov-files-$*-y) 
>> $(gcov-files-generic-y); do \
>>        echo Gcov report for $$f:;\
>> @@ -837,7 +837,7 @@ $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): 
>> check-qtest-%: $(check-qtest-y)
>>  $(patsubst %, check-%, $(check-unit-y)): check-%: %
>>      $(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
>>      $(call quiet-command, \
>> -            MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$((RANDOM % 255 + 1))} \
>> +            MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(( $${RANDOM:-0} % 255 + 
>> 1))} \
>>              gtester $(GTESTER_OPTIONS) -m=$(SPEED) $*,"GTESTER","$*")
>>      $(if $(CONFIG_GCOV),@for f in $(gcov-files-$(subst tests/,,$*)-y) 
>> $(gcov-files-generic-y); do \
>>        echo Gcov report for $$f:;\
>>
> 
>

signature.asc
Description: OpenPGP digital signature