Re: [PATCH][gdb/testsuite] Rewrite catch-follow-exec.exp

[Tom de Vries <tdevries@suse.de>]

On 10/16/18 12:11 AM, Simon Marchi wrote:
>> +    gdb_test_multiple "" "run til exit" {
>> +    "runtime error:" {
>> +        # Error in case of --enable-ubsan
>> +        fail "No runtime error"
>> +    }
> 
> Can you explain what this catches?  If this isn't there but UBSan is
> enabled, the crash isn't detected properly by the code below?

Indeed.

If I disable the fix this test-case is testing (so, I'm trying to make
the test-case fail), and I build with --disable-ubsan, I get:
...
27079 exp8 0 0 CHILDKILLED SIGSEGV {segmentation violation}
PASS: gdb.base/catch-follow-exec.exp: [lindex $result 2] == 0
FAIL: gdb.base/catch-follow-exec.exp: [lindex $result 3] == 1
FAIL: gdb.base/catch-follow-exec.exp: [llength $result] == 4
...
and with --enable-ubsan:
...
^[[1m/data/gdb_versions/devel/src/gdb/infcmd.c:2099:11:^[[1m^[[31m
runtime error: ^[[1m^[[0m^[[1mmember access wi\
thin null pointer of type 'struct thread_info'^[[1m^[[0m^M
FAIL: gdb.base/catch-follow-exec.exp: No runtime error
...

Without the extra "runtime error:" clause, I'm not detecting the fail:
...
^[[1m/data/gdb_versions/devel/src/gdb/infcmd.c:2099:11:^[[1m^[[31m
runtime error: ^[[1m^[[0m^[[1mmember access wi\
thin null pointer of type 'struct thread_info'^[[1m^[[0m^M
PASS: gdb.base/catch-follow-exec.exp: [lindex $result 2] == 0
PASS: gdb.base/catch-follow-exec.exp: [lindex $result 3] == 1
PASS: gdb.base/catch-follow-exec.exp: [llength $result] == 4
...

Thanks,
- Tom