Hi
On Tue, Sep 6, 2016 at 5:00 PM Markus Armbruster <arm...@redhat.com> wrote:
> Marc-André Lureau <marcandre.lur...@redhat.com> writes:
>
> > Learn to parse #define files provided with -f option, and skip
> > undefined #ifdef blocks in the schema.
> >
> > This is a very simple pre-processing, without stacking support or
> > evaluation (it could be implemented if needed).
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > ---
> > scripts/qapi.py | 43 ++++++++++++++++++++++++++++++++++++++++---
>
> Missing: update of docs/qapi-code-gen.txt.
>
> > 1 file changed, 40 insertions(+), 3 deletions(-)
> >
> > diff --git a/scripts/qapi.py b/scripts/qapi.py
> > index 21bc32f..d0b8a66 100644
> > --- a/scripts/qapi.py
> > +++ b/scripts/qapi.py
> > @@ -76,6 +76,7 @@ struct_types = []
> > union_types = []
> > events = []
> > all_names = {}
> > +defs = []
> >
> > #
> > # Parsing the schema into expressions
> > @@ -177,6 +178,7 @@ class QAPISchemaParser(object):
> > self.exprs.append(expr_elem)
> >
> > def accept(self):
> > + ok = True
> > while True:
> > self.tok = self.src[self.cursor]
> > self.pos = self.cursor
> > @@ -184,7 +186,19 @@ class QAPISchemaParser(object):
> > self.val = None
> >
> > if self.tok == '#':
> > - self.cursor = self.src.find('\n', self.cursor)
> > + end = self.src.find('\n', self.cursor)
> > + line = self.src[self.cursor:end+1]
> > + self.cursor = end
> > + sline = line.split()
> > + if len(defs) and len(sline) >= 1 \
> > + and sline[0] in ['ifdef', 'endif']:
> > + if sline[0] == 'ifdef':
> > + ok = sline[1] in defs
> > + elif sline[0] == 'endif':
> > + ok = True
> > + continue
> > + elif not ok:
> > + continue
> > elif self.tok in "{}:,[]":
> > return
> > elif self.tok == "'":
>
> Oww, you're abusing comments! That's horrible :)
>
Can we make this real syntax, like everything else, including 'include'?
>
>
We already abuse json, which doesn't support comments either. :) Even
without comments, our syntax is wrong and confuse most editors/validators.
> Unfortunately, the natural
>
> { 'ifdef': 'CONFIG_FOO'
> 'then': ... # ignored unless CONFIG_FOO
> 'else': ... # ignored if CONFIG_FOO (optional)
> }
>
> is awkward, because the ... have to be a single JSON value, but a QAPI
> schema isn't a single JSON value, it's a *sequence* of JSON values. A
> top-level stanza
>
> JSON-value1 JSON-value2 ...
>
> would become
>
> [ JSON-value1, JSON-value2, ... ]
>
> within a conditional. Blech.
>
> Could sacrifice the nesting and do
>
> { 'ifdef': 'CONFIG_FOO' }
> ...
> { 'endif' }
>
> Widens the gap between syntax and semantics. Editors can no longer
> easily jump over the conditional (e.g. Emacs forward-sexp). Nested
> conditionals becomes as confusing as in C. Not exactly elegant, either.
>
> Yet another option is to add 'ifdef' keys to the definitions
> themselves, i.e.
>
> { 'command': 'query-gic-capabilities', 'returns': ['GICCapability'],
> 'ifdef': 'TARGET_ARM' }
>
That's the worst of all options imho, as it makes it hard to filter out
unions/enums, ex:
@ -3446,8 +3466,10 @@
'testdev': 'ChardevCommon',
'stdio' : 'ChardevStdio',
'console': 'ChardevCommon',
+#ifdef CONFIG_SPICE
'spicevmc' : 'ChardevSpiceChannel',
'spiceport' : 'ChardevSpicePort',
+#endif
'vc' : 'ChardevVC',
'ringbuf': 'ChardevRingbuf',
I think #ifdef is the most straightforward/easy thing to do. My experience
with doc generations tells me that is really not an issue to reserve the
#\w* lines for pre-processing.
And it's a natural fit with the rest of qemu #if conditionals.
> > @@ -1707,15 +1721,36 @@ def gen_params(arg_type, boxed, extra):
> > #
> > # Common command line parsing
> > #
> > +def defile(filename):
>
> From The Collaborative International Dictionary of English v.0.48 [gcide]:
>
> Defile \De*file"\ (d[-e]*f[imac]l"), v. t. [OE. defoulen,
> -foilen, to tread down, OF. defouler; de- + fouler to trample
> (see Full, v. t.), and OE. defoulen to foul (influenced in
> form by the older verb defoilen). See File to defile,
> Foul, Defoul.]
> 1. To make foul or impure; to make filthy; to dirty; to
> befoul; to pollute.
> [1913 Webster]
>
> They that touch pitch will be defiled. --Shak.
> [1913 Webster]
>
> 2. To soil or sully; to tarnish, as reputation; to taint.
> [1913 Webster]
>
> He is . . . among the greatest prelates of this age,
> however his character may be defiled by . . . dirty
> hands. --Swift.
> [1913 Webster]
>
> 3. To injure in purity of character; to corrupt.
> [1913 Webster]
>
> Defile not yourselves with the idols of Egypt.
> --Ezek. xx. 7.
> [1913 Webster]
>
> 4. To corrupt the chastity of; to debauch; to violate; to
> rape.
> [1913 Webster]
>
> The husband murder'd and the wife defiled. --Prior.
> [1913 Webster]
>
> 5. To make ceremonially unclean; to pollute.
> [1913 Webster]
>
> That which dieth of itself, or is torn with beasts,
> he shall not eat to defile therewith. --Lev. xxii.
> 8.
> [1913 Webster]
>
> Fitting in a way; you're defiling the poor, innocent comment syntax ;)
>
ok
>
> > + f = open(filename, 'r')
> > + while 1:
>
> while True:
>
> > + line = f.readline()
> > + if not line:
> > + break
> > + while line[-2:] == '\\\n':
> > + nextline = f.readline()
> > + if not nextline:
> > + break
> > + line = line + nextline
> > + tmp = line.strip()
> > + if tmp[:1] != '#':
> > + continue
> > + tmp = tmp[1:]
> > + words = tmp.split()
> > + if words[0] != "define":
> > + continue
> > + defs.append(words[1])
> > + f.close()
>
> This parses Yet Another Language. Worse, Yet Another Undocumented
> Language. Why not JSON?
>
> Hmm, peeking ahead to PATCH 04... aha! This is for reading
> config-host.h and config-target.h. So, this actually doesn't parse
> YAUL, it parses C. Sloppily, of course.
>
Yes
>
> I guess we could instead parse config-host.mak and config-target.mak
> sloppily. Not sure which idea is more disgusting :)
>
> Could we punt evaluating conditionals to the C compiler? Instead of
> emitting TEXT when CONFIG_FOO is defined, emit
>
> #ifdef CONFIG_FOO
> TEXT
> #endif
>
>
I don't follow you
> >
> >
> > def parse_command_line(extra_options="", extra_long_options=[]):
> >
> > try:
> > opts, args = getopt.gnu_getopt(sys.argv[1:],
> > - "chp:o:" + extra_options,
> > + "chp:o:f:" + extra_options,
> > ["source", "header", "prefix=",
> > - "output-dir="] +
> extra_long_options)
> > + "output-dir=", "--defile="] +
>
> https://docs.python.org/3/library/getopt.html on the third argument:
> "The leading '--' characters should not be included in the option name."
>
ok
>
> > + extra_long_options)
> > except getopt.GetoptError as err:
> > print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
> > sys.exit(1)
> > @@ -1742,6 +1777,8 @@ def parse_command_line(extra_options="",
> extra_long_options=[]):
> > do_c = True
> > elif o in ("-h", "--header"):
> > do_h = True
> > + elif o in ("-f", "--defile"):
> > + defile(a)
> > else:
> > extra_opts.append(oa)
>
> --
Marc-André Lureau
