qapi: merge QInt and QFloat in QNum

We would like to use a same QObject type to represent numbers, whether
they are int, uint, or floats. Getters will allow some compatibility
between the various types if the number fits other representations.

Add a few more tests while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170607163635.17635-7-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[parse_stats_intervals() simplified a bit, comment in
test_visitor_in_int_overflow() tidied up, suppress bogus warnings]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 14 insertions, 16 deletions

diff --git a/qobject/json-parser.c b/qobject/json-parser.c
index c18e48a..5e80828 100644
--- a/qobject/json-parser.c
+++ b/qobject/json-parser.c
@@ -466,16 +466,16 @@ static QObject *parse_escape(JSONParserContext *ctxt, va_list *ap)
     } else if (!strcmp(token->str, "%i")) {
         return QOBJECT(qbool_from_bool(va_arg(*ap, int)));
     } else if (!strcmp(token->str, "%d")) {
-        return QOBJECT(qint_from_int(va_arg(*ap, int)));
+        return QOBJECT(qnum_from_int(va_arg(*ap, int)));
     } else if (!strcmp(token->str, "%ld")) {
-        return QOBJECT(qint_from_int(va_arg(*ap, long)));
+        return QOBJECT(qnum_from_int(va_arg(*ap, long)));
     } else if (!strcmp(token->str, "%lld") ||
                !strcmp(token->str, "%I64d")) {
-        return QOBJECT(qint_from_int(va_arg(*ap, long long)));
+        return QOBJECT(qnum_from_int(va_arg(*ap, long long)));
     } else if (!strcmp(token->str, "%s")) {
         return QOBJECT(qstring_from_str(va_arg(*ap, const char *)));
     } else if (!strcmp(token->str, "%f")) {
-        return QOBJECT(qfloat_from_double(va_arg(*ap, double)));
+        return QOBJECT(qnum_from_double(va_arg(*ap, double)));
     }
     return NULL;
 }
@@ -491,24 +491,22 @@ static QObject *parse_literal(JSONParserContext *ctxt)
     case JSON_STRING:
         return QOBJECT(qstring_from_escaped_str(ctxt, token));
     case JSON_INTEGER: {
-        /* A possibility exists that this is a whole-valued float where the
-         * fractional part was left out due to being 0 (.0). It's not a big
-         * deal to treat these as ints in the parser, so long as users of the
-         * resulting QObject know to expect a QInt in place of a QFloat in
-         * cases like these.
+        /*
+         * Represent JSON_INTEGER as QNUM_I64 if possible, else as
+         * QNUM_DOUBLE.  Note that strtoll() fails with ERANGE when
+         * it's not possible.
          *
-         * However, in some cases these values will overflow/underflow a
-         * QInt/int64 container, thus we should assume these are to be handled
-         * as QFloats/doubles rather than silently changing their values.
-         *
-         * strtoll() indicates these instances by setting errno to ERANGE
+         * qnum_get_int() will then work for any signed 64-bit
+         * JSON_INTEGER, and qnum_get_double() both for any
+         * JSON_INTEGER and any JSON_FLOAT (with precision loss for
+         * integers beyond 53 bits)
          */
         int64_t value;
 
         errno = 0; /* strtoll doesn't set errno on success */
         value = strtoll(token->str, NULL, 10);
         if (errno != ERANGE) {
-            return QOBJECT(qint_from_int(value));
+            return QOBJECT(qnum_from_int(value));
         }
         /* fall through to JSON_FLOAT */
     }
@@ -516,7 +514,7 @@ static QObject *parse_literal(JSONParserContext *ctxt)
         /* FIXME dependent on locale; a pervasive issue in QEMU */
         /* FIXME our lexer matches RFC 7159 in forbidding Inf or NaN,
          * but those might be useful extensions beyond JSON */
-        return QOBJECT(qfloat_from_double(strtod(token->str, NULL)));
+        return QOBJECT(qnum_from_double(strtod(token->str, NULL)));
     default:
         abort();
     }