Commit d8754f40 authored by Laszlo Ersek's avatar Laszlo Ersek Committed by Luiz Capitulino
Browse files

OptsVisitor: introduce list modes for interval flattening 



The new modes are equal-rank, exclusive alternatives of LM_IN_PROGRESS.
Teach opts_next_list(), opts_type_int() and opts_type_uint64() to handle
them.

Also enumerate explicitly what functions are valid to call in what modes:
- opts_next_list() is valid to call while flattening a range,
- opts_end_list(): ditto,
- lookup_scalar() is invalid to call during flattening; generated qapi
  traversal code must continue asking for the same kind of signed/unsigned
  list element until the interval is fully flattened,
- processed(): ditto.

List mode restrictions are always formulated in positive / inclusive
sense. The restrictions for lookup_scalar() and processed() are
automatically satisfied by current qapi traversals if the schema to build
is compatible with OptsVisitor.

The new list modes are not entered yet.

Signed-off-by: default avatarLaszlo Ersek <lersek@redhat.com>
Tested-by: default avatarWanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: default avatarLuiz Capitulino <lcapitulino@redhat.com>
parent d9570434

qapi/opts-visitor.c

+65 −2
Original line number Diff line number Diff line
@@ -22,7 +22,32 @@ enum ListMode 
{

    LM_NONE,             /* not traversing a list of repeated options */

    LM_STARTED,          /* opts_start_list() succeeded */

    LM_IN_PROGRESS       /* opts_next_list() has been called */



    LM_IN_PROGRESS,      /* opts_next_list() has been called.

                          *

                          * Generating the next list link will consume the most

                          * recently parsed QemuOpt instance of the repeated

                          * option.

                          *

                          * Parsing a value into the list link will examine the

                          * next QemuOpt instance of the repeated option, and

                          * possibly enter LM_SIGNED_INTERVAL or

                          * LM_UNSIGNED_INTERVAL.

                          */



    LM_SIGNED_INTERVAL,  /* opts_next_list() has been called.

                          *

                          * Generating the next list link will consume the most

                          * recently stored element from the signed interval,

                          * parsed from the most recent QemuOpt instance of the

                          * repeated option. This may consume QemuOpt itself

                          * and return to LM_IN_PROGRESS.

                          *

                          * Parsing a value into the list link will store the

                          * next element of the signed interval.

                          */



    LM_UNSIGNED_INTERVAL /* Same as above, only for an unsigned interval. */

};



typedef enum ListMode ListMode;
@@ -47,6 +72,15 @@ struct OptsVisitor 
    ListMode list_mode;

    GQueue *repeated_opts;



    /* When parsing a list of repeating options as integers, values of the form

     * "a-b", representing a closed interval, are allowed. Elements in the

     * range are generated individually.

     */

    union {

        int64_t s;

        uint64_t u;

    } range_next, range_limit;



    /* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for

     * uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does

     * not survive or escape the OptsVisitor object.
@@ -185,6 +219,22 @@ opts_next_list(Visitor *v, GenericList **list, Error **errp) 
        link = list;

        break;



    case LM_SIGNED_INTERVAL:

    case LM_UNSIGNED_INTERVAL:

        link = &(*list)->next;



        if (ov->list_mode == LM_SIGNED_INTERVAL) {

            if (ov->range_next.s < ov->range_limit.s) {

                ++ov->range_next.s;

                break;

            }

        } else if (ov->range_next.u < ov->range_limit.u) {

            ++ov->range_next.u;

            break;

        }

        ov->list_mode = LM_IN_PROGRESS;

        /* range has been completed, fall through in order to pop option */



    case LM_IN_PROGRESS: {

        const QemuOpt *opt;
@@ -211,7 +261,10 @@ opts_end_list(Visitor *v, Error **errp) 
{

    OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);



    assert(ov->list_mode == LM_STARTED || ov->list_mode == LM_IN_PROGRESS);

    assert(ov->list_mode == LM_STARTED ||

           ov->list_mode == LM_IN_PROGRESS ||

           ov->list_mode == LM_SIGNED_INTERVAL ||

           ov->list_mode == LM_UNSIGNED_INTERVAL);

    ov->repeated_opts = NULL;

    ov->list_mode = LM_NONE;

}
@@ -303,6 +356,11 @@ opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp) 
    long long val;

    char *endptr;



    if (ov->list_mode == LM_SIGNED_INTERVAL) {

        *obj = ov->range_next.s;

        return;

    }



    opt = lookup_scalar(ov, name, errp);

    if (!opt) {

        return;
@@ -328,6 +386,11 @@ opts_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp) 
    const QemuOpt *opt;

    const char *str;



    if (ov->list_mode == LM_UNSIGNED_INTERVAL) {

        *obj = ov->range_next.u;

        return;

    }



    opt = lookup_scalar(ov, name, errp);

    if (!opt) {

        return;