This is not needed with a push parser. Since it processes tokens
immediately, the JSONToken can be created directly on the stack
and does not need to copy the lexer's string data.
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260626101727.1727389-6-pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
In order to avoid stashing all the tokens corresponding to a JSON value,
embed the parsing stack and state machine in JSONParser. This is more
efficient and allows for more prompt error recovery; it also does not
make the code substantially larger than the current recursive descent
parser, though the state machine is probably a bit harder to follow.
The stack consists of QLists and QDicts corresponding to open
brackets and braces, plus optionally a QString with the current
key on top of each QDict.
After each value is parsed, it is added to the top array or dictionary
or, if the stack is empty, json_parser_feed returns the complete
QObject.
For now, json-streamer.c keeps tracking the tokens up until braces
and brackets are balanced, and then shoves the whole queue of tokens
into the push parser. The only logic change is that JSON_END_OF_INPUT
always triggers the emptying of the queue; the parser takes notice and
checks that there is nothing on the stack. Not using brace_count
and bracket_count for this is the first step towards improved separation
of concerns between json-parser.c and json-streamer.c.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260626101727.1727389-2-pbonzini@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Minor comment improvements]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The general expectation is that header files should follow the same
file/path naming scheme as the corresponding source file. There are
various historical exceptions to this practice in QEMU, with one of
the most notable being the include/qapi/qmp/ directory. Most of the
headers there correspond to source files in qobject/.
This patch corrects most of that inconsistency by creating
include/qobject/ and moving the headers for qobject/ there.
This also fixes MAINTAINERS for include/qapi/qmp/dispatch.h:
scripts/get_maintainer.pl now reports "QAPI" instead of "No
maintainers found".
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com> #s390x
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20241118151235.2665921-2-armbru@redhat.com>
[Rebased]
The lexer ignores whitespace like this:
on whitespace on non-ws spontaneously
IN_START --> IN_WHITESPACE --> JSON_SKIP --> IN_START
^ |
\__/ on whitespace
This accumulates a whitespace token in state IN_WHITESPACE, only to
throw it away on the transition via JSON_SKIP to the start state.
Wasteful. Go from IN_START to IN_START on whitespace directly,
dropping the whitespace character.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180831075841.13363-7-armbru@redhat.com>
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>
The JSON parser has three public headers, json-lexer.h, json-parser.h,
json-streamer.h. They all contain stuff that is of no interest
outside qobject/json-*.c.
Collect the public interface in include/qapi/qmp/json-parser.h, and
everything else in qobject/json-parser-int.h.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-54-armbru@redhat.com>
