qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH] trace: tighten up trace-events regex to fix bad


From: Lluís Vilanova
Subject: Re: [Qemu-devel] [PATCH] trace: tighten up trace-events regex to fix bad parse
Date: Mon, 22 Sep 2014 12:35:22 -0500
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux)

Stefan Hajnoczi writes:

> Use \w for properties and trace event names since they are both drawn
> from [a-zA-Z0-9_] character sets.

> The .* for matching properties was too aggressive and caused the
> following failure with foo(int rc) "(this is a test)":

>   Traceback (most recent call last):
>     File "scripts/tracetool.py", line 139, in <module>
>       main(sys.argv)
>     File "scripts/tracetool.py", line 134, in main
>       binary=binary, probe_prefix=probe_prefix)
>     File "scripts/tracetool/__init__.py", line 334, in generate
>       events = _read_events(fevents)
>     File "scripts/tracetool/__init__.py", line 262, in _read_events
>       res.append(Event.build(line))
>     File "scripts/tracetool/__init__.py", line 225, in build
>       return Event(name, props, fmt, args, arg_fmts)
>     File "scripts/tracetool/__init__.py", line 185, in __init__
>       % ", ".join(unknown_props))
>   ValueError: Unknown properties: foo(int, rc)

> Cc: Lluís Vilanova <address@hidden>
> Reported-by: Eric Auger <address@hidden>
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> ---
>  scripts/tracetool/__init__.py | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
> index 36c789d..474f11b 100644
> --- a/scripts/tracetool/__init__.py
> +++ b/scripts/tracetool/__init__.py
> @@ -140,8 +140,8 @@ class Event(object):
>          The format strings for each argument.
>      """
 
> -    _CRE = re.compile("((?P<props>.*)\s+)?"
> -                      "(?P<name>[^(\s]+)"
> +    _CRE = re.compile("((?P<props>\w*)\s+)?"
> +                      "(?P<name>\w+)"
>                        "\((?P<args>[^)]*)\)"
>                        "\s*"
>                        "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"

The previous implementation allowed multiple properties. Maybe this should be
instead (which still allows multiple properties):

    "((?P<props>[\w\s]+)\s+)?"
    "(?P<name>\w+)\s*"
    ...


Thanks,
  Lluis

-- 
 "And it's much the same thing with knowledge, for whenever you learn
 something new, the whole world becomes that much richer."
 -- The Princess of Pure Reason, as told by Norton Juster in The Phantom
 Tollbooth



reply via email to

[Prev in Thread] Current Thread [Next in Thread]