| Message ID | 20190913105205.7581-3-philmd@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | trace: Forbid trailing newline in event format | expand |
On 9/13/19 6:52 AM, Philippe Mathieu-Daudé wrote: > Event format ending with newlines confuse the trace reports. > Forbid them. > > Add a check to refuse new format added with trailing newline: > > $ make > [...] > GEN hw/misc/trace.h > Traceback (most recent call last): > File "scripts/tracetool.py", line 152, in <module> > main(sys.argv) > File "scripts/tracetool.py", line 143, in main > events.extend(tracetool.read_events(fh, arg)) > File "scripts/tracetool/__init__.py", line 367, in read_events > event = Event.build(line) > File "scripts/tracetool/__init__.py", line 281, in build > raise ValueError("Event format can not end with a newline character") > ValueError: Error at hw/misc/trace-events:121: Event format can not end with a newline character > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > docs/devel/tracing.txt | 2 ++ > scripts/tracetool/__init__.py | 3 +++ > 2 files changed, 5 insertions(+) > > diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt > index 76e492a489..8231bbf5d1 100644 > --- a/docs/devel/tracing.txt > +++ b/docs/devel/tracing.txt > @@ -112,6 +112,8 @@ Trace events should use types as follows: > Format strings should reflect the types defined in the trace event. Take > special care to use PRId64 and PRIu64 for int64_t and uint64_t types, > respectively. This ensures portability between 32- and 64-bit platforms. > +Format strings must not end with a newline character. It is the responsibility > +of backends to adapt line ending for proper logging. > > Each event declaration will start with the event name, then its arguments, > finally a format string for pretty-printing. For example: > diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py > index 6fca674936..57df74e67c 100644 > --- a/scripts/tracetool/__init__.py > +++ b/scripts/tracetool/__init__.py > @@ -277,6 +277,9 @@ class Event(object): > if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1: > raise ValueError("Event format '%m' is forbidden, pass the error " > "as an explicit trace argument") > + if fmt.endswith("\\n\""): > + raise ValueError("Event format must not end with a newline " It's barely worth mentioning, but you can use r"\n" for cases like this, if it makes it easier to read.
On 9/13/19 10:01 PM, John Snow wrote: > On 9/13/19 6:52 AM, Philippe Mathieu-Daudé wrote: >> Event format ending with newlines confuse the trace reports. >> Forbid them. >> >> Add a check to refuse new format added with trailing newline: >> >> $ make >> [...] >> GEN hw/misc/trace.h >> Traceback (most recent call last): >> File "scripts/tracetool.py", line 152, in <module> >> main(sys.argv) >> File "scripts/tracetool.py", line 143, in main >> events.extend(tracetool.read_events(fh, arg)) >> File "scripts/tracetool/__init__.py", line 367, in read_events >> event = Event.build(line) >> File "scripts/tracetool/__init__.py", line 281, in build >> raise ValueError("Event format can not end with a newline character") >> ValueError: Error at hw/misc/trace-events:121: Event format can not end with a newline character >> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> >> --- >> docs/devel/tracing.txt | 2 ++ >> scripts/tracetool/__init__.py | 3 +++ >> 2 files changed, 5 insertions(+) >> >> diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt >> index 76e492a489..8231bbf5d1 100644 >> --- a/docs/devel/tracing.txt >> +++ b/docs/devel/tracing.txt >> @@ -112,6 +112,8 @@ Trace events should use types as follows: >> Format strings should reflect the types defined in the trace event. Take >> special care to use PRId64 and PRIu64 for int64_t and uint64_t types, >> respectively. This ensures portability between 32- and 64-bit platforms. >> +Format strings must not end with a newline character. It is the responsibility >> +of backends to adapt line ending for proper logging. >> >> Each event declaration will start with the event name, then its arguments, >> finally a format string for pretty-printing. For example: >> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py >> index 6fca674936..57df74e67c 100644 >> --- a/scripts/tracetool/__init__.py >> +++ b/scripts/tracetool/__init__.py >> @@ -277,6 +277,9 @@ class Event(object): >> if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1: >> raise ValueError("Event format '%m' is forbidden, pass the error " >> "as an explicit trace argument") >> + if fmt.endswith("\\n\""): >> + raise ValueError("Event format must not end with a newline " > > It's barely worth mentioning, but you can use r"\n" for cases like this, > if it makes it easier to read. TIL Python r"" :) This would be r"\n\"", right? We need to match the trailing '"'. Same length, not sure which string is easier to review =)
On 9/13/19 5:00 PM, Philippe Mathieu-Daudé wrote: > On 9/13/19 10:01 PM, John Snow wrote: >> On 9/13/19 6:52 AM, Philippe Mathieu-Daudé wrote: >>> Event format ending with newlines confuse the trace reports. >>> Forbid them. >>> >>> Add a check to refuse new format added with trailing newline: >>> >>> $ make >>> [...] >>> GEN hw/misc/trace.h >>> Traceback (most recent call last): >>> File "scripts/tracetool.py", line 152, in <module> >>> main(sys.argv) >>> File "scripts/tracetool.py", line 143, in main >>> events.extend(tracetool.read_events(fh, arg)) >>> File "scripts/tracetool/__init__.py", line 367, in read_events >>> event = Event.build(line) >>> File "scripts/tracetool/__init__.py", line 281, in build >>> raise ValueError("Event format can not end with a newline character") >>> ValueError: Error at hw/misc/trace-events:121: Event format can not end with a newline character >>> >>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> >>> --- >>> docs/devel/tracing.txt | 2 ++ >>> scripts/tracetool/__init__.py | 3 +++ >>> 2 files changed, 5 insertions(+) >>> >>> diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt >>> index 76e492a489..8231bbf5d1 100644 >>> --- a/docs/devel/tracing.txt >>> +++ b/docs/devel/tracing.txt >>> @@ -112,6 +112,8 @@ Trace events should use types as follows: >>> Format strings should reflect the types defined in the trace event. Take >>> special care to use PRId64 and PRIu64 for int64_t and uint64_t types, >>> respectively. This ensures portability between 32- and 64-bit platforms. >>> +Format strings must not end with a newline character. It is the responsibility >>> +of backends to adapt line ending for proper logging. >>> >>> Each event declaration will start with the event name, then its arguments, >>> finally a format string for pretty-printing. For example: >>> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py >>> index 6fca674936..57df74e67c 100644 >>> --- a/scripts/tracetool/__init__.py >>> +++ b/scripts/tracetool/__init__.py >>> @@ -277,6 +277,9 @@ class Event(object): >>> if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1: >>> raise ValueError("Event format '%m' is forbidden, pass the error " >>> "as an explicit trace argument") >>> + if fmt.endswith("\\n\""): >>> + raise ValueError("Event format must not end with a newline " >> >> It's barely worth mentioning, but you can use r"\n" for cases like this, >> if it makes it easier to read. > > TIL Python r"" :) > > This would be r"\n\"", right? We need to match the trailing '"'. > Same length, not sure which string is easier to review =) > Ah, wow, I did misread this. It's confusing! In this case, you can use r'\n"' to get the job done. (My r-b stands, anyway.) --js
diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt index 76e492a489..8231bbf5d1 100644 --- a/docs/devel/tracing.txt +++ b/docs/devel/tracing.txt @@ -112,6 +112,8 @@ Trace events should use types as follows: Format strings should reflect the types defined in the trace event. Take special care to use PRId64 and PRIu64 for int64_t and uint64_t types, respectively. This ensures portability between 32- and 64-bit platforms. +Format strings must not end with a newline character. It is the responsibility +of backends to adapt line ending for proper logging. Each event declaration will start with the event name, then its arguments, finally a format string for pretty-printing. For example: diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py index 6fca674936..57df74e67c 100644 --- a/scripts/tracetool/__init__.py +++ b/scripts/tracetool/__init__.py @@ -277,6 +277,9 @@ class Event(object): if fmt.find("%m") != -1 or fmt_trans.find("%m") != -1: raise ValueError("Event format '%m' is forbidden, pass the error " "as an explicit trace argument") + if fmt.endswith("\\n\""): + raise ValueError("Event format must not end with a newline " + "character") if len(fmt_trans) > 0: fmt = [fmt_trans, fmt]
Event format ending with newlines confuse the trace reports. Forbid them. Add a check to refuse new format added with trailing newline: $ make [...] GEN hw/misc/trace.h Traceback (most recent call last): File "scripts/tracetool.py", line 152, in <module> main(sys.argv) File "scripts/tracetool.py", line 143, in main events.extend(tracetool.read_events(fh, arg)) File "scripts/tracetool/__init__.py", line 367, in read_events event = Event.build(line) File "scripts/tracetool/__init__.py", line 281, in build raise ValueError("Event format can not end with a newline character") ValueError: Error at hw/misc/trace-events:121: Event format can not end with a newline character Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> --- docs/devel/tracing.txt | 2 ++ scripts/tracetool/__init__.py | 3 +++ 2 files changed, 5 insertions(+)