json: use fpclassify() or its helper functions

diff --git a/src/basic/macro.h b/src/basic/macro.h
index bcac55620e2cf99acdfb67feb5d6f076afa2e0e4..237117db12a76f146dedde2a80fe00746f33ae2e 100644 (file)
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -87,10 +87,6 @@
         _Pragma("GCC diagnostic push")
 #endif
 
-#define DISABLE_WARNING_FLOAT_EQUAL \
-        _Pragma("GCC diagnostic push");                                 \
-        _Pragma("GCC diagnostic ignored \"-Wfloat-equal\"")
-
 #define DISABLE_WARNING_TYPE_LIMITS \
         _Pragma("GCC diagnostic push");                                 \
         _Pragma("GCC diagnostic ignored \"-Wtype-limits\"")

diff --git a/src/shared/json.c b/src/shared/json.c
index 13bc44a9edab61c5e666fb6c47476c578bc3956b..67b6b75fa8319cb9e27033fb54c24c0f6f2b70cd 100644 (file)
--- a/src/shared/json.c
+++ b/src/shared/json.c
@@ -2,7 +2,6 @@
 
 #include <errno.h>
 #include <locale.h>
-#include <math.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <sys/types.h>
@@ -18,6 +17,7 @@
 #include "json-internal.h"
 #include "json.h"
 #include "macro.h"
+#include "math-util.h"
 #include "memory-util.h"
 #include "string-table.h"
 #include "string-util.h"
@@ -253,9 +253,7 @@ static JsonVariant *json_variant_formalize(JsonVariant *v) {
                 return json_variant_unsigned(v) == 0 ? JSON_VARIANT_MAGIC_ZERO_UNSIGNED : v;
 
         case JSON_VARIANT_REAL:
-                DISABLE_WARNING_FLOAT_EQUAL;
-                return json_variant_real(v) == 0.0 ? JSON_VARIANT_MAGIC_ZERO_REAL : v;
-                REENABLE_WARNING;
+                return iszero_safe(json_variant_real(v)) ? JSON_VARIANT_MAGIC_ZERO_REAL : v;
 
         case JSON_VARIANT_STRING:
                 return isempty(json_variant_string(v)) ? JSON_VARIANT_MAGIC_EMPTY_STRING : v;
@@ -352,16 +350,16 @@ int json_variant_new_real(JsonVariant **ret, double d) {
 
         assert_return(ret, -EINVAL);
 
-        DISABLE_WARNING_FLOAT_EQUAL;
-        if (d == 0.0) {
-                *ret = JSON_VARIANT_MAGIC_ZERO_REAL;
+        r = fpclassify(d);
+        switch (r) {
+        case FP_NAN:
+        case FP_INFINITE:
+                /* JSON doesn't know NaN, +Infinity or -Infinity. Let's silently convert to 'null'. */
+                *ret = JSON_VARIANT_MAGIC_NULL;
                 return 0;
-        }
-        REENABLE_WARNING;
 
-        /* JSON doesn't know NaN, +Infinity or -Infinity. Let's silently convert to 'null'. */
-        if (isnan(d) || isinf(d)) {
-                *ret = JSON_VARIANT_MAGIC_NULL;
+        case FP_ZERO:
+                *ret = JSON_VARIANT_MAGIC_ZERO_REAL;
                 return 0;
         }
 
@@ -914,10 +912,8 @@ int64_t json_variant_integer(JsonVariant *v) {
 
                 converted = (int64_t) v->value.real;
 
-                DISABLE_WARNING_FLOAT_EQUAL;
-                if ((double) converted == v->value.real)
+                if (fp_equal((double) converted, v->value.real))
                         return converted;
-                REENABLE_WARNING;
 
                 log_debug("Real %g requested as integer, and cannot be converted losslessly, returning 0.", v->value.real);
                 return 0;
@@ -961,10 +957,8 @@ uint64_t json_variant_unsigned(JsonVariant *v) {
 
                 converted = (uint64_t) v->value.real;
 
-                DISABLE_WARNING_FLOAT_EQUAL;
-                if ((double) converted == v->value.real)
+                if (fp_equal((double) converted, v->value.real))
                         return converted;
-                REENABLE_WARNING;
 
                 log_debug("Real %g requested as unsigned integer, and cannot be converted losslessly, returning 0.", v->value.real);
                 return 0;
@@ -1153,15 +1147,11 @@ bool json_variant_has_type(JsonVariant *v, JsonVariantType type) {
         if (rt == JSON_VARIANT_UNSIGNED && type == JSON_VARIANT_REAL)
                 return (uint64_t) (double) v->value.unsig == v->value.unsig;
 
-        DISABLE_WARNING_FLOAT_EQUAL;
-
         /* Any real that can be converted losslessly to an integer and back may also be considered an integer */
         if (rt == JSON_VARIANT_REAL && type == JSON_VARIANT_INTEGER)
-                return (double) (int64_t) v->value.real == v->value.real;
+                return fp_equal((double) (int64_t) v->value.real, v->value.real);
         if (rt == JSON_VARIANT_REAL && type == JSON_VARIANT_UNSIGNED)
-                return (double) (uint64_t) v->value.real == v->value.real;
-
-        REENABLE_WARNING;
+                return fp_equal((double) (uint64_t) v->value.real, v->value.real);
 
         return false;
 }
@@ -1314,9 +1304,7 @@ bool json_variant_equal(JsonVariant *a, JsonVariant *b) {
                 return json_variant_unsigned(a) == json_variant_unsigned(b);
 
         case JSON_VARIANT_REAL:
-                DISABLE_WARNING_FLOAT_EQUAL;
-                return json_variant_real(a) == json_variant_real(b);
-                REENABLE_WARNING;
+                return fp_equal(json_variant_real(a), json_variant_real(b));
 
         case JSON_VARIANT_BOOLEAN:
                 return json_variant_boolean(a) == json_variant_boolean(b);

diff --git a/src/test/test-json.c b/src/test/test-json.c
index 415ada22bf0868ed8b2db20474cf61a0b7e65904..d22485630ac8b2e84c1ee67e298f467461127877 100644 (file)
--- a/src/test/test-json.c
+++ b/src/test/test-json.c
@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <float.h>
-#include <math.h>
 
 #include "alloc-util.h"
 #include "escape.h"
@@ -9,6 +8,7 @@
 #include "fileio.h"
 #include "json-internal.h"
 #include "json.h"
+#include "math-util.h"
 #include "string-util.h"
 #include "strv.h"
 #include "tests.h"
@@ -239,9 +239,7 @@ static void test_zeroes(JsonVariant *v) {
                 assert_se(json_variant_integer(w) == 0);
                 assert_se(json_variant_unsigned(w) == 0U);
 
-                DISABLE_WARNING_FLOAT_EQUAL;
-                assert_se(json_variant_real(w) == 0.0L);
-                REENABLE_WARNING;
+                assert_se(iszero_safe(json_variant_real(w)));
 
                 assert_se(json_variant_is_integer(w));
                 assert_se(json_variant_is_unsigned(w));
@@ -511,7 +509,7 @@ static void test_float_match(JsonVariant *v) {
         const double delta = 0.0001;
 
         assert_se(json_variant_is_array(v));
-        assert_se(json_variant_elements(v) == 9);
+        assert_se(json_variant_elements(v) == 11);
         assert_se(fabs(1.0 - (DBL_MIN / json_variant_real(json_variant_by_index(v, 0)))) <= delta);
         assert_se(fabs(1.0 - (DBL_MAX / json_variant_real(json_variant_by_index(v, 1)))) <= delta);
         assert_se(json_variant_is_null(json_variant_by_index(v, 2))); /* nan is not supported by json → null */
@@ -528,6 +526,12 @@ static void test_float_match(JsonVariant *v) {
         assert_se(json_variant_is_real(json_variant_by_index(v, 8)) &&
                   json_variant_is_integer(json_variant_by_index(v, 8)) &&
                   json_variant_integer(json_variant_by_index(v, 8)) == -10);
+        assert_se(json_variant_is_real(json_variant_by_index(v, 9)) &&
+                  !json_variant_is_integer(json_variant_by_index(v, 9)));
+        assert_se(fabs(1.0 - (DBL_MIN / 2 / json_variant_real(json_variant_by_index(v, 9)))) <= delta);
+        assert_se(json_variant_is_real(json_variant_by_index(v, 10)) &&
+                  !json_variant_is_integer(json_variant_by_index(v, 10)));
+        assert_se(fabs(1.0 - (-DBL_MIN / 2 / json_variant_real(json_variant_by_index(v, 10)))) <= delta);
 }
 
 TEST(float) {
@@ -543,7 +547,9 @@ TEST(float) {
                                              JSON_BUILD_REAL(HUGE_VAL),
                                              JSON_BUILD_REAL(0),
                                              JSON_BUILD_REAL(10),
-                                             JSON_BUILD_REAL(-10))) >= 0);
+                                             JSON_BUILD_REAL(-10),
+                                             JSON_BUILD_REAL(DBL_MIN / 2),
+                                             JSON_BUILD_REAL(-DBL_MIN / 2))) >= 0);
 
         json_variant_dump(v, JSON_FORMAT_COLOR|JSON_FORMAT_PRETTY, NULL, NULL);