Re: [Qemu-devel] [PATCH] trace: fix group name generation

[Greg Kurz]

On Thu, 17 Nov 2016 17:34:44 +0800
Fam Zheng <address@hidden> wrote:

> On Thu, 11/17 10:10, Greg Kurz wrote:
> > On Thu, 17 Nov 2016 16:07:38 +0800
> > Fam Zheng <address@hidden> wrote:
> >   
> > > On Thu, 10/20 15:25, Stefan Hajnoczi wrote:  
> > > > > 
> > > > > I have two other patches ready to fix the current situation:
> > > > > - one using os.getcwd() to guess the build directory
> > > > > - one implementing --group as mentioned in my other mail
> > > > > 
> > > > > But the one that filters unwanted characters is a less intrusive
> > > > > workaround.    
> > > > 
> > > > If Dan's patches will eliminate the issue then we can take a workaround.
> > > > 
> > > > Any more comments about Greg's patch before I merge it?    
> > > 
> > > Should we include this in -rc1? I still see a build error today.
> > > 
> > > Fam
> > >   
> > 
> > Hi Fam,
> > 
> > My patch was partly superseded by this commit:
> > 
> > commit 630b210b9abbf362905a2096c22c5eb1d6224e77
> > Author: Stefan Weil <address@hidden>
> > Date:   Thu Oct 13 20:29:30 2016 +0200
> > 
> >     Fix build for less common build directories names
> > 
> > which does:
> > 
> > -    return re.sub(r"/|-", "_", dirname)
> > +    return re.sub(r"[^A-Za-z0-9]", "_", dirname)
> > 
> > What is the build error you're hitting ?  
> 
> The substracted parts (basedir and dirname) are different paths for 
> out-of-tree
> build, and the "dirname" after the nonsense substraction as fed into re.sub()
> could still start with a number. In my case the source is at
> 
>     /var/tmp/aaa-qemu-clone
> 
> and the build dir is
> 
>     /var/tmp/qemu-aio-poll-v2
> 
> Then I get an error as:
> 
> trace/generated-tracers.c:15950:13: error: invalid suffix "_trace_events" on 
> integer constant
>  TraceEvent *2_trace_events[] = {
>              ^
> trace/generated-tracers.c:15950:13: error: expected identifier or ‘(’ before 
> numeric constant
> trace/generated-tracers.c: In function ‘trace_2_register_events’:
> trace/generated-tracers.c:17949:32: error: invalid suffix "_trace_events" on 
> integer constant
>      trace_event_register_group(2_trace_events);
>                                 ^
> make: *** [trace/generated-tracers.o] Error 1

My patch was addressing this as well... it is unfortunate it got dumped. :-\

I guess the following should be enough to fix your issue... but I'm no tracetool
expert and I cannot assure it doesn't break anything elsewhere...

-    return re.sub(r"[^A-Za-z0-9]", "_", dirname)
+    return "_" + re.sub(r"[^A-Za-z0-9]", "_", dirname)

Cheers.

--
Greg