Re: How to use test-nlist

[Mark Wielaard <mark at klomp dot org>]

On Thu, May 23, 2019 at 04:52:39PM +0800, Yu, Mingli wrote:
> I run some tests about elfutils, but one test as test-nlist always fails as
> below:
> 
> # ./tests/test-nlist
> nlist failed

You are supposed to run it with make check.
make check TESTS=test-nlist

test-nlist tries to run nlist on itself.
So it has to be in the current working directory.
As you do below:

> # cd tests
> # ./test-nlist  -d
> nl[0].n_name = "var"
> nl[0].n_value = 0
> nl[0].n_scnum = 0
> nl[0].n_type = 0
> nl[0].n_sclass = 0
> nl[0].n_numaux = 0
> 
> nl[1].n_name = "bss"
> nl[1].n_value = 0
> nl[1].n_scnum = 0
> nl[1].n_type = 0
> nl[1].n_sclass = 0
> nl[1].n_numaux = 0
> 
> nl[2].n_name = "main"
> nl[2].n_value = 0
> nl[2].n_scnum = 0
> nl[2].n_type = 0
> nl[2].n_sclass = 0
> nl[2].n_numaux = 0
> 
> nl[3].n_name = "foo"
> nl[3].n_value = 0
> nl[3].n_scnum = 0
> nl[3].n_type = 0
> nl[3].n_sclass = 0
> nl[3].n_numaux = 0
> 
> nl[4].n_name = "not-there"
> nl[4].n_value = 0
> nl[4].n_scnum = 0
> nl[4].n_type = 0
> nl[4].n_sclass = 0
> nl[4].n_numaux = 0
> # echo $?
> 1

For some reason all the n_ fields come out as zero.  That is not what
the test expects (except for the last "not-there" entry. It should
look somethng like:

nl[0].n_name = "var"
nl[0].n_value = 16456
nl[0].n_scnum = 24
nl[0].n_type = 1
nl[0].n_sclass = 0
nl[0].n_numaux = 0

nl[1].n_name = "bss"
nl[1].n_value = 16464
nl[1].n_scnum = 25
nl[1].n_type = 1
nl[1].n_sclass = 0
nl[1].n_numaux = 0

nl[2].n_name = "main"
nl[2].n_value = 4224
nl[2].n_scnum = 14
nl[2].n_type = 2
nl[2].n_sclass = 0
nl[2].n_numaux = 0

nl[3].n_name = "foo"
nl[3].n_value = 4880
nl[3].n_scnum = 14
nl[3].n_type = 2
nl[3].n_sclass = 0
nl[3].n_numaux = 0

nl[4].n_name = "not-there"
nl[4].n_value = 0
nl[4].n_scnum = 0
nl[4].n_type = 0
nl[4].n_sclass = 0
nl[4].n_numaux = 0

Basically nlist fills in the n_value and n_scnum with the st_value and
st_shndx of the symbol named if found.

As you can see for me it corresponds to the values found by:

$ eu-readelf -s ./test-nlist | egrep ' (var|bss|main|foo)'
   58: 0000000000004048      4 OBJECT  GLOBAL DEFAULT       24 var
   61: 0000000000004050      4 OBJECT  GLOBAL DEFAULT       25 bss
   66: 0000000000001310      3 FUNC    GLOBAL DEFAULT       14 foo
   71: 0000000000001080    408 FUNC    GLOBAL DEFAULT       14 main

Hope that helps you debug.

Cheers,

Mark