Re: [PATCH][gdb/testsuite] Fix gdb.btrace/tsx.exp on system with tsx disabled in microcode

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

On 7/12/21 4:35 PM, Metzger, Markus T wrote:
> Hello Tom,
> 
>> diff --git a/gdb/testsuite/gdb.btrace/tsx.exp b/gdb/testsuite/gdb.btrace/tsx.exp
>> index ccde1ea807e..66f6305e50a 100644
>> --- a/gdb/testsuite/gdb.btrace/tsx.exp
>> +++ b/gdb/testsuite/gdb.btrace/tsx.exp
>> @@ -59,6 +59,11 @@ set abort_2 [multi_line \
>>      "\[0-9\]*\t   0x\[0-9a-f\]+ <test\\+\[0-9\]+>:\tmov\[^\\\r\\\n\]*" \
>>      "\[0-9\]*\t   0x\[0-9a-f\]+ <test\\+\[0-9\]+>:\tret\[^\\\r\\\n\]*" \
>>      ]
>> +set abort_3 \
>> +    [multi_line \
>> +	 "$decimal\t   $hex <main\\+$decimal>:\t\[^\\\r\\\n\]*" \
>> +	 "$decimal\t   $hex <test\\+$decimal>:\tmov\[^\\\r\\\n\]*" \
>> +	 "$decimal\t   $hex <test\\+$decimal>:\tret\[^\\\r\\\n\]*"]
>>  
>>  set test "speculation indication"
>>  gdb_test_multiple "record instruction-history" $test {
>> @@ -68,6 +73,9 @@ gdb_test_multiple "record instruction-history" $test {
>>      -re "$abort_2.*$gdb_prompt $" {
>>          pass $test
>>      }
>> +    -re -wrap "$abort_3.*" {
>> +        pass $gdb_test_name
>> +    }
>>      -re  "$begin_to_end.*$gdb_prompt $" {
>>          pass $test
>>      }
> 
> We allow (and require) a single instruction in main.
> That works if we stopped
> directly at the call.  I don't think we can guarantee that.
> 

Well, we require at least one instruction.  There can be more that one.
So that should work if we stopped directly at the call, or before.

The current form is only wrong if there is no instruction from main in
the trace, which I don't expect given that we start recording in main.
Is my understanding wrong here?

> In the other patterns, I put .* in front to ignore any compiler-generated
> code prior to the actual test.

A .* at the start of a -re clause is redundant, so it's best to leave
that out, to avoid confusion.

Are you satisfied with this explanation, or do still require changes?

Thanks,
- Tom