diff options
Diffstat (limited to 'qobject/qnum.c')
| -rw-r--r-- | qobject/qnum.c | 24 |
1 files changed, 3 insertions, 21 deletions
diff --git a/qobject/qnum.c b/qobject/qnum.c index 7012fc57f2..bf1240ecec 100644 --- a/qobject/qnum.c +++ b/qobject/qnum.c @@ -161,37 +161,19 @@ double qnum_get_double(QNum *qn) char *qnum_to_string(QNum *qn) { - char *buffer; - int len; - switch (qn->kind) { case QNUM_I64: return g_strdup_printf("%" PRId64, qn->u.i64); case QNUM_U64: return g_strdup_printf("%" PRIu64, qn->u.u64); case QNUM_DOUBLE: - /* FIXME: snprintf() is locale dependent; but JSON requires + /* FIXME: g_strdup_printf() 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. */ - buffer = g_strdup_printf("%f" , qn->u.dbl); - len = strlen(buffer); - while (len > 0 && buffer[len - 1] == '0') { - len--; - } - - if (len && buffer[len - 1] == '.') { - buffer[len - 1] = 0; - } else { - buffer[len] = 0; - } - - return buffer; + /* 17 digits suffice for IEEE double */ + return g_strdup_printf("%.17g", qn->u.dbl); } assert(0); |