Merge pull request #1278 from michich/nicer-asserts

nicer assert messages

4 files changed, 23 insertions, 14 deletions

diff --git a/src/basic/macro.h b/src/basic/macro.h
index cbc3ca97b8..248f7a86dd 100644
--- a/src/basic/macro.h
+++ b/src/basic/macro.h
@@ -123,8 +123,11 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
         return 1UL << (sizeof(u) * 8 - __builtin_clzl(u - 1UL));
 }
 
-#define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
-
+#define ELEMENTSOF(x)                                                    \
+        __extension__ (__builtin_choose_expr(                            \
+                !__builtin_types_compatible_p(typeof(x), typeof(&*(x))), \
+                sizeof(x)/sizeof((x)[0]),                                \
+                (void)0))
 /*
  * container_of - cast a member of a structure out to the containing structure
  * @ptr: the pointer to the member.
@@ -213,18 +216,20 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
                 (__x / __y + !!(__x % __y));                            \
         })
 
-#define assert_se(expr)                                                 \
+#define assert_message_se(expr, message)                                \
         do {                                                            \
                 if (_unlikely_(!(expr)))                                \
-                        log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
-        } while (false)                                                 \
+                        log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+        } while (false)
+
+#define assert_se(expr) assert_message_se(expr, #expr)
 
 /* We override the glibc assert() here. */
 #undef assert
 #ifdef NDEBUG
 #define assert(expr) do {} while(false)
 #else
-#define assert(expr) assert_se(expr)
+#define assert(expr) assert_message_se(expr, #expr)
 #endif
 
 #define assert_not_reached(t)                                           \
@@ -249,19 +254,19 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
         REENABLE_WARNING
 #endif
 
-#define assert_log(expr) ((_likely_(expr))      \
-        ? (true)                                \
-        : (log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
+#define assert_log(expr, message) ((_likely_(expr))                     \
+        ? (true)                                                        \
+        : (log_assert_failed_return(message, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
 
 #define assert_return(expr, r)                                          \
         do {                                                            \
-                if (!assert_log(expr))                                  \
+                if (!assert_log(expr, #expr))                           \
                         return (r);                                     \
         } while (false)
 
 #define assert_return_errno(expr, r, err)                               \
         do {                                                            \
-                if (!assert_log(expr)) {                                \
+                if (!assert_log(expr, #expr)) {                         \
                         errno = err;                                    \
                         return (r);                                     \
                 }                                                       \
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
index de881e8fe1..1af01541fc 100644
--- a/src/basic/time-util.h
+++ b/src/basic/time-util.h
@@ -112,6 +112,8 @@ bool timezone_is_valid(const char *name);
 
 clockid_t clock_boottime_or_monotonic(void);
 
-#define xstrftime(buf, fmt, tm) assert_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0)
+#define xstrftime(buf, fmt, tm) \
+        assert_message_se(strftime(buf, ELEMENTSOF(buf), fmt, tm) > 0, \
+                          "xstrftime: " #buf "[] must be big enough")
 
 int get_timezone(char **timezone);
diff --git a/src/basic/util.h b/src/basic/util.h
index c7dff9a86d..8abaa740b2 100644
--- a/src/basic/util.h
+++ b/src/basic/util.h
@@ -374,7 +374,9 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(cpu_set_t*, CPU_FREE);
 
 cpu_set_t* cpu_set_malloc(unsigned *ncpus);
 
-#define xsprintf(buf, fmt, ...) assert_se((size_t) snprintf(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__) < ELEMENTSOF(buf))
+#define xsprintf(buf, fmt, ...) \
+        assert_message_se((size_t) snprintf(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__) < ELEMENTSOF(buf), \
+                          "xsprintf: " #buf "[] must be big enough")
 
 int files_same(const char *filea, const char *fileb);
 
diff --git a/src/libsystemd/sd-bus/bus-internal.h b/src/libsystemd/sd-bus/bus-internal.h
index 7af61a9433..e399701beb 100644
--- a/src/libsystemd/sd-bus/bus-internal.h
+++ b/src/libsystemd/sd-bus/bus-internal.h
@@ -396,6 +396,6 @@ int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 
 #define bus_assert_return(expr, r, error)                               \
         do {                                                            \
-                if (!assert_log(expr))                                  \
+                if (!assert_log(expr, #expr))                           \
                         return sd_bus_error_set_errno(error, r);        \
         } while (false)