On 7/20/20 12:50 PM, Roman Bolshakov wrote:
> On Sun, Jul 19, 2020 at 03:52:08PM +0200, Philippe Mathieu-Daudé wrote:
>> On 7/17/20 11:35 AM, Roman Bolshakov wrote:
>>> dtrace USDT is fully supported since OS X 10.6. There are a few
>>> peculiarities compared to other dtrace flavors.
>>>
>>> 1. It doesn't accept empty files.
>>> 2. It doesn't recognize bool type but accepts C99 _Bool.
>>> 3. It converts int8_t * in probe points to char * in
>>> header files and introduces [-Wpointer-sign] warning.
>>>
>>> Cc: Cameron Esfahani <di...@apple.com>
>>> Signed-off-by: Roman Bolshakov <r.bolsha...@yadro.com>
>>> ---
>>> scripts/tracetool/format/d.py | 15 ++++++++++++++-
>>> 1 file changed, 14 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/scripts/tracetool/format/d.py b/scripts/tracetool/format/d.py
>>> index 0afb5f3f47..353722f89c 100644
>>> --- a/scripts/tracetool/format/d.py
>>> +++ b/scripts/tracetool/format/d.py
>>> @@ -13,6 +13,7 @@ __email__ = "stefa...@redhat.com"
>>>
>>>
>>> from tracetool import out
>>> +from sys import platform
>>>
>>>
>>> # Reserved keywords from
>>> @@ -34,7 +35,8 @@ def generate(events, backend, group):
>>>
>>> # SystemTap's dtrace(1) warns about empty "provider qemu {}" but is
>>> happy
>>> # with an empty file. Avoid the warning.
>>> - if not events:
>>> + # But dtrace on macOS can't deal with empty files.
>>> + if not events and platform != "darwin":
>>
>> or?
>
> no, the event list is empty for some files where all events are
> disabled (e.g. hppa/trace-events), so it should have an "and" here. This
> limits early exit only on macOS.
Ah yes you are right, I misread it.
> The precendence looks correct:
>
> https://docs.python.org/3/reference/expressions.html#operator-precedence
>
>>
>>> return
>>>
>>> out('/* This file is autogenerated by tracetool, do not edit. */'
>>> @@ -44,6 +46,17 @@ def generate(events, backend, group):
>>> for e in events:
>>> args = []
>>> for type_, name in e.args:
>>> + if platform == "darwin":
>>> + # macOS dtrace accepts only C99 _Bool
>>
>> Why not do that for all platforms?
>>
>
> Because I can only test the changes on darwin :)
> I don't know how other dtrace flavors behave and whether it is an issue
> for dtrace on Linux/Solaris/FreeBSD/etc.
>
> Thanks,
> Roman
>
>>> + if type_ == 'bool':
>>> + type_ = '_Bool'
>>> + if type_ == 'bool *':
>>> + type_ = '_Bool *'
>>> + # It converts int8_t * in probe points to char * in header
>>> + # files and introduces [-Wpointer-sign] warning.
>>> + # Avoid it by changing probe type to signed char *
>>> beforehand.
>>> + if type_ == 'int8_t *':
>>> + type_ = 'signed char *'
>>> if name in RESERVED_WORDS:
>>> name += '_'
>>> args.append(type_ + ' ' + name)
>>>
>>
>
