qemu/qobject
Markus Armbruster c0ee3afa7f json: Make lexer's "character consumed" logic less confusing
The lexer uses macro TERMINAL_NEEDED_LOOKAHEAD() to decide whether a
state transition consumes the input character.  It returns true when
the state transition is defined with the TERMINAL() macro.  To detect
that, it checks whether input '\0' would have resulted in the same
state transition, and the new state is not IN_ERROR.

Why does that even work?  For all states, the new state on input '\0'
is either IN_ERROR or defined with TERMINAL().  If the state
transition equals the one we'd get for input '\0', it goes to IN_ERROR
or to the argument of TERMINAL().  We never use TERMINAL(IN_ERROR),
because it makes no sense.  Thus, if it doesn't go to IN_ERROR, it
must be defined with TERMINAL().

Since this isn't quite confusing enough, we negate the result to get
@char_consumed, and ignore it when @flush is true.

Instead of deriving the lookahead bit from the state transition, make
it explicit.  This is easier to understand, and a bit more flexible,
too.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180831075841.13363-4-armbru@redhat.com>
2018-09-24 18:06:09 +02:00
..
block-qdict.c qdict: Make qdict_extract_subqdict() accept dst = NULL 2018-08-15 12:50:39 +02:00
json-lexer.c json: Make lexer's "character consumed" logic less confusing 2018-09-24 18:06:09 +02:00
json-parser-int.h json: Make lexer's "character consumed" logic less confusing 2018-09-24 18:06:09 +02:00
json-parser.c json: Update references to RFC 7159 to RFC 8259 2018-08-24 20:27:14 +02:00
json-streamer.c json: Clean up headers 2018-08-24 20:26:37 +02:00
Makefile.objs qobject: Move block-specific qdict code to block-qdict.c 2018-06-15 14:49:44 +02:00
qbool.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00
qdict.c qobject: Move block-specific qdict code to block-qdict.c 2018-06-15 14:49:44 +02:00
qjson.c json: Clean up headers 2018-08-24 20:26:37 +02:00
qlist.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00
qlit.c qapi: Replace qobject_to_X(o) by qobject_to(X, o) 2018-03-19 14:58:36 -05:00
qnull.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00
qnum.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00
qobject.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00
qstring.c qobject: Drop superfluous includes of qemu-common.h 2018-08-24 20:26:37 +02:00