Re: [PATCH v4 04/15] gdb/testsuite: change gdb.base/nodebug.exp to not fail with clang

[Bruno Larsen <blarsen@redhat.com>]

Thanks, pushed!

Cheers,
Bruno

On 12/09/2022 11:08, Andrew Burgess wrote:
> Bruno Larsen via Gdb-patches <gdb-patches@sourceware.org> writes:
>
>> Clang organizes the variables differently to gcc in the original version
>> of this code, leading to the following differences when testing
>> p (int*) &dataglobal + 1
>>
>> gcc:
>> $16 = (int *) 0x404034 <datalocal>
>>
>> clang:
>> $16 = (int *) 0x404034 <dataglobal8>
>>
>> However, since the important part of this test doesn't seem to be which
>> symbol is linked, but rather if GDB is correctly increasing the
>> address. This test was changed to actually measure address changes,
>> instead of assuming the ordering and naming of symbols.
>>
>> Co-Authored-By: Andrew Burgess <aburgess@redhat.com>
> This looks good.  I think this patch can be merged.
>
> Thanks,
> Andrew
>
>
>> ---
>>   gdb/testsuite/gdb.base/nodebug.exp | 12 ++++++++++--
>>   1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/gdb/testsuite/gdb.base/nodebug.exp b/gdb/testsuite/gdb.base/nodebug.exp
>> index 68a21eb07dd..1deed596095 100644
>> --- a/gdb/testsuite/gdb.base/nodebug.exp
>> +++ b/gdb/testsuite/gdb.base/nodebug.exp
>> @@ -170,6 +170,7 @@ if [nodebug_runto inner] then {
>>       set unk_type_re "has unknown type.*to its declared type"
>>       set ptr_math_re "Cannot perform pointer math on incomplete type \"$data_var_type\", try casting to a known type, or void \\*\\."
>>       set not_mem_re "Attempt to take address of value not located in memory\\."
>> +    set any_label_regexp "<\[^>\]+>"
>>   
>>       set dataglobal_unk_re "dataglobal.*$unk_type_re"
>>   
>> @@ -183,7 +184,7 @@ if [nodebug_runto inner] then {
>>   	{"dataglobal + 1"		""   $dataglobal_unk_re					$dataglobal_unk_re}
>>   	{"&dataglobal"			""   "\\($data_var_type \\*\\) $hex <dataglobal>"	" = $data_var_type \\*"}
>>   	{"&dataglobal + 1"		""   $ptr_math_re					$ptr_math_re}
>> -	{"(int *) &dataglobal + 1"	""   " = \\(int \\*\\) $hex <datalocal>"		"int \\*"}
>> +	{"(int *) &dataglobal + 1"	""   " = \\(int \\*\\) $hex $any_label_regexp"		"int \\*"}
>>   	{"&(int) dataglobal + 1"	""   $not_mem_re					$not_mem_re}
>>   	{"&dataglobal, &dataglobal"	""   "\\($data_var_type \\*\\) $hex <dataglobal>"	" = $data_var_type \\*"}
>>   	{"*dataglobal"			""   $dataglobal_unk_re					$dataglobal_unk_re}
>> @@ -214,7 +215,14 @@ if [nodebug_runto inner] then {
>>   	gdb_test "whatis $exp" $whatis
>>   	gdb_test "ptype $exp" $whatis
>>       }
>> -
>> +
>> +    # Check that pointer arithmetic works as expected.
>> +    set addr1 [get_hexadecimal_valueof "&dataglobal" "*UNKNOWN*"]
>> +    set addr2 [get_hexadecimal_valueof "(int *) &dataglobal + 1" "*UNKNOWN*"]
>> +    set offset [expr $addr2 - $addr1]
>> +    set int_size [get_integer_valueof "sizeof (int)" "*UNKNOWN*"]
>> +    gdb_assert { $offset == $int_size }
>> +
>>       # The only symbol xcoff puts out for statics is for the TOC entry.
>>       # Possible, but hairy, for gdb to deal.  Right now it doesn't, it
>>       # doesn't know the variables exist at all.
>> -- 
>> 2.31.1