[PATCH] gdb/testsuite: show evaluation errors in gdb_assert

[Simon Marchi]

On 2020-11-23 1:46 p.m., Luis Machado via Gdb-patches wrote:
> On 11/23/20 3:35 PM, Simon Marchi via Gdb-patches wrote:
>> Let's say you put this gdb_assert in a test:
>>
>>      gdb_assert "some invalid tcl code"
>>
>> You just get:
>>
>>      FAIL: gdb.base/template.exp: some invalid tcl code
>>
>> That's not very easy to debug, since you don't know what's invalid in
>> your code.
>>
>> Change gdb_assert to print the error message when catch's return code is
>> 1 (TCL_ERROR).  The "warning" is shown both on stdout and in the log
>> file.  Mark the test as unresolved, because the evaluation error means
>> we couldn't reach a valid pass/fail conclusion.
>>
>> gdb/testsuite/ChangeLog:
>>
>>     * lib/gdb.exp (gdb_assert): Show error message on error.
>>
>> Change-Id: Ie6477859554e909ed8d07fb2769c6f2f55e7cce6
>> ---
>>   gdb/testsuite/lib/gdb.exp | 9 ++++++++-
>>   1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
>> index c42933b3f41e..f2954fd5192b 100644
>> --- a/gdb/testsuite/lib/gdb.exp
>> +++ b/gdb/testsuite/lib/gdb.exp
>> @@ -1728,7 +1728,14 @@ proc gdb_assert { condition {message ""} } {
>>       }
>>         set code [catch {uplevel 1 expr $condition} res]
>> -    if {$code != 0 || !$res} {
>> +    if {$code == 1} {
>> +    # If code is 1 (TCL_ERROR), it means evaluation failed and res contains
>> +    # an error message.  Print the error message, and set res to 0 since we
>> +    # want to return a boolean.
>> +    warning "While evaluating expression in gdb_assert: $res"
>> +    unresolved $message
>> +    set res 0
>> +    } elseif { !$res } {
>>       fail $message
>>       } else {
>>       pass $message
>>
> 
> Looks OK to me. That's good to have more meaningful output.

Thanks for the review, I pushed it.

Simon