[Qemu-devel] [PATCH v4 5/5] tests: Add check-qobject for equality tests

[Max Reitz <mreitz@redhat.com>]

Add a new test file (check-qobject.c) for unit tests that concern
QObjects as a whole.

Its only purpose for now is to test the qobject_is_equal() function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/Makefile.include |   4 +-
 qobject/qnum.c         |  16 +-
 tests/check-qobject.c  | 404 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 417 insertions(+), 7 deletions(-)
 create mode 100644 tests/check-qobject.c

diff --git a/tests/Makefile.include b/tests/Makefile.include
index 42e17e2..07b130c 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -18,6 +18,7 @@ check-unit-y += tests/check-qlist$(EXESUF)
 gcov-files-check-qlist-y = qobject/qlist.c
 check-unit-y += tests/check-qnull$(EXESUF)
 gcov-files-check-qnull-y = qobject/qnull.c
+check-unit-y += tests/check-qobject$(EXESUF)
 check-unit-y += tests/check-qjson$(EXESUF)
 gcov-files-check-qjson-y = qobject/qjson.c
 check-unit-y += tests/test-qobject-output-visitor$(EXESUF)
@@ -508,7 +509,7 @@ GENERATED_FILES += tests/test-qapi-types.h tests/test-qapi-visit.h \
 	tests/test-qmp-introspect.h
 
 test-obj-y = tests/check-qnum.o tests/check-qstring.o tests/check-qdict.o \
-	tests/check-qlist.o tests/check-qnull.o \
+	tests/check-qlist.o tests/check-qnull.o tests/check-qobject.o \
 	tests/check-qjson.o \
 	tests/test-coroutine.o tests/test-string-output-visitor.o \
 	tests/test-string-input-visitor.o tests/test-qobject-output-visitor.o \
@@ -541,6 +542,7 @@ tests/check-qstring$(EXESUF): tests/check-qstring.o $(test-util-obj-y)
 tests/check-qdict$(EXESUF): tests/check-qdict.o $(test-util-obj-y)
 tests/check-qlist$(EXESUF): tests/check-qlist.o $(test-util-obj-y)
 tests/check-qnull$(EXESUF): tests/check-qnull.o $(test-util-obj-y)
+tests/check-qobject$(EXESUF): tests/check-qobject.o $(test-util-obj-y)
 tests/check-qjson$(EXESUF): tests/check-qjson.o $(test-util-obj-y)
 tests/check-qom-interface$(EXESUF): tests/check-qom-interface.o $(test-qom-obj-y)
 tests/check-qom-proplist$(EXESUF): tests/check-qom-proplist.o $(test-qom-obj-y)
diff --git a/qobject/qnum.c b/qobject/qnum.c
index 96c348c..3d029f6 100644
--- a/qobject/qnum.c
+++ b/qobject/qnum.c
@@ -217,12 +217,16 @@ QNum *qobject_to_qnum(const QObject *obj)
 /**
  * qnum_is_equal(): Test whether the two QNums are equal
  *
- * Negative integers are never considered equal to unsigned integers.
- * Doubles are only considered equal to integers if their fractional
- * part is zero and their integral part is exactly equal to the
- * integer.  Because doubles have limited precision, there are
- * therefore integers which do not have an equal double (e.g.
- * INT64_MAX).
+ * This comparison is done independently of the internal
+ * representation.  Any two numbers are considered equal if they are
+ * mathmatically equal, that means:
+ * - Negative integers are never considered equal to unsigned
+ *   integers.
+ * - Floating point values are only considered equal to integers if
+ *   their fractional part is zero and their integral part is exactly
+ *   equal to the integer.  Because doubles have limited precision,
+ *   there are therefore integers which do not have an equal floating
+ *   point value (e.g. INT64_MAX).
  */
 bool qnum_is_equal(const QObject *x, const QObject *y)
 {
diff --git a/tests/check-qobject.c b/tests/check-qobject.c
new file mode 100644
index 0000000..fd964bf
--- /dev/null
+++ b/tests/check-qobject.c
@@ -0,0 +1,404 @@
+/*
+ * Generic QObject unit-tests.
+ *
+ * Copyright (C) 2017 Red Hat Inc.
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+
+#include "qapi/qmp/types.h"
+#include "qemu-common.h"
+
+/* Marks the end of the test_equality() argument list.
+ * We cannot use NULL there because that is a valid argument. */
+static QObject _test_equality_end_of_arguments;
+
+/**
+ * Test whether all variadic QObject *arguments are equal (@expected
+ * is true) or whether they are all not equal (@expected is false).
+ * Every QObject is tested to be equal to itself (to test
+ * reflexivity), all tests are done both ways (to test symmetry), and
+ * transitivity is not assumed but checked (each object is compared to
+ * every other one).
+ *
+ * Note that qobject_is_equal() is not really an equivalence relation,
+ * so this function may not be used for all objects (reflexivity is
+ * not guaranteed, e.g. in the case of a QNum containing NaN).
+ */
+static void do_test_equality(bool expected, ...)
+{
+    va_list ap_count, ap_extract;
+    QObject **args;
+    int arg_count = 0;
+    int i, j;
+
+    va_start(ap_count, expected);
+    va_copy(ap_extract, ap_count);
+    while (va_arg(ap_count, QObject *) != &_test_equality_end_of_arguments) {
+        arg_count++;
+    }
+    va_end(ap_count);
+
+    args = g_new(QObject *, arg_count);
+    for (i = 0; i < arg_count; i++) {
+        args[i] = va_arg(ap_extract, QObject *);
+    }
+    va_end(ap_extract);
+
+    for (i = 0; i < arg_count; i++) {
+        g_assert(qobject_is_equal(args[i], args[i]) == true);
+
+        for (j = i + 1; j < arg_count; j++) {
+            g_assert(qobject_is_equal(args[i], args[j]) == expected);
+        }
+    }
+}
+
+#define test_equality(expected, ...) \
+    do_test_equality(expected, __VA_ARGS__, &_test_equality_end_of_arguments)
+
+static void do_free_all(int _, ...)
+{
+    va_list ap;
+    QObject *obj;
+
+    va_start(ap, _);
+    while ((obj = va_arg(ap, QObject *)) != NULL) {
+        qobject_decref(obj);
+    }
+    va_end(ap);
+}
+
+#define free_all(...) \
+    do_free_all(0, __VA_ARGS__, NULL)
+
+static void qobject_is_equal_null_test(void)
+{
+    test_equality(false, qnull(), NULL);
+}
+
+static void qobject_is_equal_num_test(void)
+{
+    QNum *u0, *i0, *d0, *d0p25, *dnan, *um42, *im42, *dm42;
+    QNum *umax, *imax, *umax_exact, *umax_exact_p1;
+    QNum *dumax, *dimax, *dumax_exact, *dumax_exact_p1;
+    QString *s0, *s_empty;
+    QBool *bfalse;
+
+    u0 = qnum_from_uint(0u);
+    i0 = qnum_from_int(0);
+    d0 = qnum_from_double(0.0);
+    d0p25 = qnum_from_double(0.25);
+    dnan = qnum_from_double(0.0 / 0.0);
+    um42 = qnum_from_uint((uint64_t)-42);
+    im42 = qnum_from_int(-42);
+    dm42 = qnum_from_int(-42.0);
+
+    /* 2^64 - 1: Not exactly representable as a double (needs 64 bits
+     * of precision, but double only has 53).  The double equivalent
+     * may be either 2^64 or 2^64 - 2^11. */
+    umax = qnum_from_uint(UINT64_MAX);
+
+    /* 2^63 - 1: Not exactly representable as a double (needs 63 bits
+     * of precision, but double only has 53).  The double equivalent
+     * may be either 2^63 or 2^63 - 2^10. */
+    imax = qnum_from_int(INT64_MAX);
+    /* 2^64 - 2^11: Exactly representable as a double (the least
+     * significant 11 bits are set to 0, so we only need the 53 bits
+     * of precision double offers).  This is the maximum value which
+     * is exactly representable both as a uint64_t and a double. */
+    umax_exact = qnum_from_uint(UINT64_MAX - 0x7ff);
+
+    /* 2^64 - 2^11 + 1: Not exactly representable as a double (needs
+     * 64 bits again), but whereas (double)UINT64_MAX may be rounded
+     * up to 2^64, this will most likely be rounded down to
+     * 2^64 - 2^11. */
+    umax_exact_p1 = qnum_from_uint(UINT64_MAX - 0x7ff + 1);
+
+    dumax = qnum_from_double((double)qnum_get_uint(umax));
+    dimax = qnum_from_double((double)qnum_get_int(imax));
+    dumax_exact = qnum_from_double((double)qnum_get_uint(umax_exact));
+    dumax_exact_p1 = qnum_from_double((double)qnum_get_uint(umax_exact_p1));
+
+    s0 = qstring_from_str("0");
+    s_empty = qstring_new();
+    bfalse = qbool_from_bool(false);
+
+    /* The internal representation should not matter, as long as the
+     * precision is sufficient */
+    test_equality(true, u0, i0, d0);
+
+    /* No automatic type conversion */
+    test_equality(false, u0, s0, s_empty, bfalse, qnull(), NULL);
+    test_equality(false, i0, s0, s_empty, bfalse, qnull(), NULL);
+    test_equality(false, d0, s0, s_empty, bfalse, qnull(), NULL);
+
+    /* Do not round */
+    test_equality(false, u0, d0p25);
+    test_equality(false, i0, d0p25);
+
+    /* Do not assume any object is equal to itself -- note however
+     * that NaN cannot occur in a JSON object anyway. */
+    g_assert(qobject_is_equal(QOBJECT(dnan), QOBJECT(dnan)) == false);
+
+    /* No unsigned overflow */
+    test_equality(false, um42, im42);
+    test_equality(false, um42, dm42);
+    test_equality(true, im42, dm42);
+
+
+    /*
+     * Floating point values must match integers exactly to be
+     * considered equal; it does not suffice that converting the
+     * integer to a double yields the same value.
+     * Each of the following four tests follows the same pattern:
+     * 1. Check that both QNum objects compare unequal because they
+     *    are (mathematically).  The third test is an exception,
+     *    because here they are indeed equal.
+     * 2. Check that when converting the integer QNum to a double,
+     *    that value is equal to the double QNum.  We can thus see
+     *    that the QNum comparison does not simply convert the
+     *    integer to a floating point value (in a potentially lossy
+     *    operation).
+     * 3. Sanity checks: Check that the double QNum has the expected
+     *    value (which may be one of two in case it was rounded; the
+     *    exact result is then implementation-defined).
+     *    If there are multiple valid values, check that they are
+     *    distinct values when represented as double (just proving
+     *    that our assumptions about the precision of doubles are
+     *    correct).
+     *
+     * The first two tests are interesting because they may involve a
+     * double value which is out of the uint64_t or int64_t range,
+     * respectively (if it is rounded to 2^64 or 2^63 during
+     * conversion).
+     *
+     * Since both are intended to involve rounding the value up during
+     * conversion, we also have the fourth test which is indended to
+     * test behavior if the value was rounded down. This is the fourth
+     * test.
+     *
+     * The third test simply proves that the value used in the fourth
+     * test is indeed just one above a number that can be exactly
+     * represented in a double.
+     */
+
+    test_equality(false, umax, dumax);
+    g_assert(qnum_get_double(umax) == qnum_get_double(dumax));
+    g_assert(qnum_get_double(dumax) == 0x1p64 ||
+             qnum_get_double(dumax) == 0x1p64 - 0x1p11);
+    g_assert(0x1p64 != 0x1p64 - 0x1p11);
+
+    test_equality(false, imax, dimax);
+    g_assert(qnum_get_double(imax) == qnum_get_double(dimax));
+    g_assert(qnum_get_double(dimax) == 0x1p63 ||
+             qnum_get_double(dimax) == 0x1p63 - 0x1p10);
+    g_assert(0x1p63 != 0x1p63 - 0x1p10);
+
+    test_equality(true, umax_exact, dumax_exact);
+    g_assert(qnum_get_double(umax_exact) == qnum_get_double(dumax_exact));
+    g_assert(qnum_get_double(dumax_exact) == 0x1p64 - 0x1p11);
+
+    test_equality(false, umax_exact_p1, dumax_exact_p1);
+    g_assert(qnum_get_double(umax_exact_p1) == qnum_get_double(dumax_exact_p1));
+    g_assert(qnum_get_double(dumax_exact_p1) == 0x1p64 ||
+             qnum_get_double(dumax_exact_p1) == 0x1p64 - 0x1p11);
+    g_assert(0x1p64 != 0x1p64 - 0x1p11);
+
+
+    free_all(u0, i0, d0, d0p25, dnan, um42, im42, dm42,
+             umax, imax, umax_exact, umax_exact_p1,
+             dumax, dimax, dumax_exact, dumax_exact_p1,
+             s0, s_empty, bfalse);
+}
+
+static void qobject_is_equal_bool_test(void)
+{
+    QBool *btrue_0, *btrue_1, *bfalse_0, *bfalse_1;
+
+    /* Automatic type conversion is tested in the QNum test */
+
+    btrue_0 = qbool_from_bool(true);
+    btrue_1 = qbool_from_bool(true);
+    bfalse_0 = qbool_from_bool(false);
+    bfalse_1 = qbool_from_bool(false);
+
+    test_equality(true, btrue_0, btrue_1);
+    test_equality(true, bfalse_0, bfalse_1);
+    test_equality(false, btrue_0, bfalse_0);
+    test_equality(false, btrue_1, bfalse_1);
+
+    free_all(btrue_0, btrue_1, bfalse_0, bfalse_1);
+}
+
+static void qobject_is_equal_string_test(void)
+{
+    QString *str_base, *str_whitespace_0, *str_whitespace_1, *str_whitespace_2;
+    QString *str_whitespace_3, *str_case, *str_built;
+
+    str_base = qstring_from_str("foo");
+    str_whitespace_0 = qstring_from_str(" foo");
+    str_whitespace_1 = qstring_from_str("foo ");
+    str_whitespace_2 = qstring_from_str("foo\b");
+    str_whitespace_3 = qstring_from_str("fooo\b");
+    str_case = qstring_from_str("Foo");
+
+    /* Should yield "foo" */
+    str_built = qstring_from_substr("form", 0, 1);
+    qstring_append_chr(str_built, 'o');
+
+    test_equality(false, str_base, str_whitespace_0, str_whitespace_1,
+                         str_whitespace_2, str_whitespace_3, str_case);
+
+    test_equality(true, str_base, str_built);
+
+    free_all(str_base, str_whitespace_0, str_whitespace_1, str_whitespace_2,
+             str_whitespace_3, str_case, str_built);
+}
+
+static void qobject_is_equal_list_test(void)
+{
+    QList *list_0, *list_1, *list_cloned;
+    QList *list_reordered, *list_longer, *list_shorter;
+
+    list_0 = qlist_new();
+    list_1 = qlist_new();
+    list_reordered = qlist_new();
+    list_longer = qlist_new();
+    list_shorter = qlist_new();
+
+    qlist_append_int(list_0, 1);
+    qlist_append_int(list_0, 2);
+    qlist_append_int(list_0, 3);
+
+    qlist_append_int(list_1, 1);
+    qlist_append_int(list_1, 2);
+    qlist_append_int(list_1, 3);
+
+    qlist_append_int(list_reordered, 1);
+    qlist_append_int(list_reordered, 3);
+    qlist_append_int(list_reordered, 2);
+
+    qlist_append_int(list_longer, 1);
+    qlist_append_int(list_longer, 2);
+    qlist_append_int(list_longer, 3);
+    qlist_append_obj(list_longer, qnull());
+
+    qlist_append_int(list_shorter, 1);
+    qlist_append_int(list_shorter, 2);
+
+    list_cloned = qlist_copy(list_0);
+
+    test_equality(true, list_0, list_1, list_cloned);
+    test_equality(false, list_0, list_reordered, list_longer, list_shorter);
+
+    /* With a NaN in it, the list should no longer compare equal to
+     * itself */
+    qlist_append(list_0, qnum_from_double(0.0 / 0.0));
+    g_assert(qobject_is_equal(QOBJECT(list_0), QOBJECT(list_0)) == false);
+
+    free_all(list_0, list_1, list_cloned, list_reordered, list_longer, list_shorter);
+}
+
+static void qobject_is_equal_dict_test(void)
+{
+    Error *local_err = NULL;
+    QDict *dict_0, *dict_1, *dict_cloned;
+    QDict *dict_different_key, *dict_different_value, *dict_different_null_key;
+    QDict *dict_longer, *dict_shorter, *dict_nested;
+    QDict *dict_crumpled;
+
+    dict_0 = qdict_new();
+    dict_1 = qdict_new();
+    dict_different_key = qdict_new();
+    dict_different_value = qdict_new();
+    dict_different_null_key = qdict_new();
+    dict_longer = qdict_new();
+    dict_shorter = qdict_new();
+    dict_nested = qdict_new();
+
+    qdict_put_int(dict_0, "f.o", 1);
+    qdict_put_int(dict_0, "bar", 2);
+    qdict_put_int(dict_0, "baz", 3);
+    qdict_put_obj(dict_0, "null", qnull());
+
+    qdict_put_int(dict_1, "f.o", 1);
+    qdict_put_int(dict_1, "bar", 2);
+    qdict_put_int(dict_1, "baz", 3);
+    qdict_put_obj(dict_1, "null", qnull());
+
+    qdict_put_int(dict_different_key, "F.o", 1);
+    qdict_put_int(dict_different_key, "bar", 2);
+    qdict_put_int(dict_different_key, "baz", 3);
+    qdict_put_obj(dict_different_key, "null", qnull());
+
+    qdict_put_int(dict_different_value, "f.o", 42);
+    qdict_put_int(dict_different_value, "bar", 2);
+    qdict_put_int(dict_different_value, "baz", 3);
+    qdict_put_obj(dict_different_value, "null", qnull());
+
+    qdict_put_int(dict_different_null_key, "f.o", 1);
+    qdict_put_int(dict_different_null_key, "bar", 2);
+    qdict_put_int(dict_different_null_key, "baz", 3);
+    qdict_put_obj(dict_different_null_key, "none", qnull());
+
+    qdict_put_int(dict_longer, "f.o", 1);
+    qdict_put_int(dict_longer, "bar", 2);
+    qdict_put_int(dict_longer, "baz", 3);
+    qdict_put_int(dict_longer, "xyz", 4);
+    qdict_put_obj(dict_longer, "null", qnull());
+
+    qdict_put_int(dict_shorter, "f.o", 1);
+    qdict_put_int(dict_shorter, "bar", 2);
+    qdict_put_int(dict_shorter, "baz", 3);
+
+    qdict_put(dict_nested, "f", qdict_new());
+    qdict_put_int(qdict_get_qdict(dict_nested, "f"), "o", 1);
+    qdict_put_int(dict_nested, "bar", 2);
+    qdict_put_int(dict_nested, "baz", 3);
+    qdict_put_obj(dict_nested, "null", qnull());
+
+    dict_cloned = qdict_clone_shallow(dict_0);
+
+    test_equality(true, dict_0, dict_1, dict_cloned);
+    test_equality(false, dict_0, dict_different_key, dict_different_value,
+                         dict_different_null_key, dict_longer, dict_shorter,
+                         dict_nested);
+
+    dict_crumpled = qobject_to_qdict(qdict_crumple(dict_1, &local_err));
+    g_assert(!local_err);
+    test_equality(true, dict_crumpled, dict_nested);
+
+    qdict_flatten(dict_nested);
+    test_equality(true, dict_0, dict_nested);
+
+    /* Containing an NaN value will make this dict compare unequal to
+     * itself */
+    qdict_put(dict_0, "NaN", qnum_from_double(0.0 / 0.0));
+    g_assert(qobject_is_equal(QOBJECT(dict_0), QOBJECT(dict_0)) == false);
+
+    free_all(dict_0, dict_1, dict_cloned, dict_different_key,
+             dict_different_value, dict_different_null_key, dict_longer,
+             dict_shorter, dict_nested, dict_crumpled);
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+
+    g_test_add_func("/public/qobject_is_equal_null",
+                    qobject_is_equal_null_test);
+    g_test_add_func("/public/qobject_is_equal_num", qobject_is_equal_num_test);
+    g_test_add_func("/public/qobject_is_equal_bool",
+                    qobject_is_equal_bool_test);
+    g_test_add_func("/public/qobject_is_equal_string",
+                    qobject_is_equal_string_test);
+    g_test_add_func("/public/qobject_is_equal_list",
+                    qobject_is_equal_list_test);
+    g_test_add_func("/public/qobject_is_equal_dict",
+                    qobject_is_equal_dict_test);
+
+    return g_test_run();
+}
-- 
2.9.4