Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-02-09' into staging

QAPI patches for 2016-02-09

# gpg: Signature made Tue 09 Feb 2016 10:55:51 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-02-09: (31 commits)
  qapi: Add missing JSON files in build dependencies
  qapi: Fix compilation failure on MIPS and SPARC
  qmp: Don't abuse stack to track qmp-output root
  qmp: Fix reference-counting of qnull on empty output visit
  qapi: Drop unused error argument for list and implicit struct
  qapi: Tighten qmp_input_end_list()
  qapi: Drop unused 'kind' for struct/enum visit
  qapi: Swap 'name' in visit_* callbacks to match public API
  qom: Swap 'name' next to visitor in ObjectPropertyAccessor
  qapi: Swap visit_* arguments for consistent 'name' placement
  qom: Use typedef for Visitor
  qapi: Don't cast Enum* to int*
  qapi: Consolidate visitor small integer callbacks
  qapi: Make all visitors supply uint64 callbacks
  qapi: Prefer type_int64 over type_int in visitors
  qapi-visit: Kill unused visit_end_union()
  qapi: Track all failures between visit_start/stop
  qapi: Improve generated event use of qapi visitor
  balloon: Improve use of qapi visitor
  vl: Ensure qapi visitor properly ends struct visit
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/qobject/qjson.c b/qobject/qjson.c
index b8cc4ca964..06dc210cbf 100644
--- a/qobject/qjson.c
+++ b/qobject/qjson.c
@@ -238,6 +238,15 @@ static void to_json(const QObject *obj, QString *str, int pretty, int indent)
         char buffer[1024];
         int len;
 
+        /* FIXME: snprintf() is locale dependent; but JSON requires
+         * numbers to be formatted as if in the C locale. Dependence
+         * on C locale is a pervasive issue in QEMU. */
+        /* FIXME: This risks printing Inf or NaN, which are not valid
+         * JSON values. */
+        /* FIXME: the default precision of 6 for %f often causes
+         * rounding errors; we should be using DBL_DECIMAL_DIG (17),
+         * and only rounding to a shorter number if the result would
+         * still produce the same floating point value.  */
         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
         while (len > 0 && buffer[len - 1] == '0') {
             len--;
@@ -248,7 +257,7 @@ static void to_json(const QObject *obj, QString *str, int pretty, int indent)
         } else {
             buffer[len] = 0;
         }
-        
+
         qstring_append(str, buffer);
         break;
     }