Re: [Qemu-devel] [PATCH] trace: include filename when printing parser error messages

[Philippe Mathieu-Daudé]

On 03/06/2018 12:46 PM, Daniel P. Berrangé wrote:
> Improves error messages from:
> 
>   ValueError: Error on line 72: need more than 1 value to unpack
> 
> To
> 
>   ValueError: Error at /home/berrange/src/virt/qemu/trace-events:72:
>     need more than 1 value to unpack
> 
> Signed-off-by: Daniel P. Berrangé <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  scripts/simpletrace.py        | 4 ++--
>  scripts/tracetool.py          | 2 +-
>  scripts/tracetool/__init__.py | 6 ++++--
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
> index a3a6315055..fefc0806b8 100755
> --- a/scripts/simpletrace.py
> +++ b/scripts/simpletrace.py
> @@ -168,7 +168,7 @@ class Analyzer(object):
>  def process(events, log, analyzer, read_header=True):
>      """Invoke an analyzer on each event in a log."""
>      if isinstance(events, str):
> -        events = read_events(open(events, 'r'))
> +        events = read_events(open(events, 'r'), events)
>      if isinstance(log, str):
>          log = open(log, 'rb')
>  
> @@ -233,7 +233,7 @@ def run(analyzer):
>                           '<trace-file>\n' % sys.argv[0])
>          sys.exit(1)
>  
> -    events = read_events(open(sys.argv[1], 'r'))
> +    events = read_events(open(sys.argv[1], 'r'), sys.argv[1])
>      process(events, sys.argv[2], analyzer, read_header=read_header)
>  
>  if __name__ == '__main__':
> diff --git a/scripts/tracetool.py b/scripts/tracetool.py
> index c55a21518b..fe2b0771f2 100755
> --- a/scripts/tracetool.py
> +++ b/scripts/tracetool.py
> @@ -142,7 +142,7 @@ def main(args):
>      events = []
>      for arg in args:
>          with open(arg, "r") as fh:
> -            events.extend(tracetool.read_events(fh))
> +            events.extend(tracetool.read_events(fh, arg))
>  
>      try:
>          tracetool.generate(events, arg_group, arg_format, arg_backends,
> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
> index 52cc687ae3..b645be30d1 100644
> --- a/scripts/tracetool/__init__.py
> +++ b/scripts/tracetool/__init__.py
> @@ -336,13 +336,15 @@ class Event(object):
>                       self)
>  
>  
> -def read_events(fobj):
> +def read_events(fobj, fname):
>      """Generate the output for the given (format, backends) pair.
>  
>      Parameters
>      ----------
>      fobj : file
>          Event description file.
> +    fname : str
> +        Name of event file
>  
>      Returns a list of Event objects
>      """
> @@ -357,7 +359,7 @@ def read_events(fobj):
>          try:
>              event = Event.build(line)
>          except ValueError as e:
> -            arg0 = 'Error on line %d: %s' % (lineno, e.args[0])
> +            arg0 = 'Error at %s:%d: %s' % (fname, lineno, e.args[0])
>              e.args = (arg0,) + e.args[1:]
>              raise
>  
>