Date: Sat, 4 Oct 2014 00:59:57 -0700 From: Bryan Cantrill <bryancantrill@gmail.com> To: Mark Johnston <markj@freebsd.org> Cc: "dtrace-discuss@lists.dtrace.org" <dtrace-discuss@lists.dtrace.org>, freebsd-dtrace@freebsd.org Subject: Re: [dtrace-discuss] dtrace keywords in postfix expressions Message-ID: <CAAm8y%2BjJcp9=3DywYO%2B3gYRPbCtTR4g_H0fJ9CdPV7No0rac7Q@mail.gmail.com> In-Reply-To: <20141004041300.GA21821@charmander.picturesperfect.net> References: <20141004041300.GA21821@charmander.picturesperfect.net>
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Nothing like cracking open dt_grammar.y to get the blood flowing! ;) I
don't think the change looks unreasonable; how does the test suite fare?
If this is no way breaks extant D programs, I'm all for it...
- Bryan
On Fri, Oct 3, 2014 at 9:13 PM, Mark Johnston via dtrace-discuss <
dtrace-discuss@lists.dtrace.org> wrote:
> Hello,
>
> DTrace has a few keywords which are not keywords in C/C++ (e.g.
> "provider"). One annoyance which has come up a few times is the fact
> that such keywords cannot be used in expressions which would be valid in
> the code being traced. For example, FreeBSD's struct g_consumer contains
> a field called "provider", and attempting to run the following snippet of
> D results in a syntax error:
>
> fbt::g_vfs_done:entry {printf("%s",
> stringof(args[0]->bio_from->provider->name));}
>
> I don't see any reason the D grammar can't support this, however. The
> patch at [1] attempts to fix this problem by allowing certain keywords
> to appear in the place of identifiers in postfix expressions. It's not a
> complete solution since it doesn't handle types or probe names, but it's a
> start. Any thoughts on this approach?
>
> Thanks!
> -Mark
>
> [1] http://people.freebsd.org/~markj/patches/dtrace_keywords.diff
>
>
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