From: Jens Gustedt <Jens.Gustedt@inria.fr>
To: musl@lists.openwall.com
Subject: [musl] [C23 divers headers 12/17] C23: change the assert macro to ... arguments
Date: Wed, 19 Apr 2023 14:17:04 +0200 [thread overview]
Message-ID: <1fb2486a2f84e40acb728524b0f074d6ce073602.1684932861.git.Jens.Gustedt@inria.fr> (raw)
In-Reply-To: <cover.1684932861.git.Jens.Gustedt@inria.fr>
Macro arguments are ambiguate fellows. A single C expression such as
(struct toto){ 1, 2}.a appears as two macro arguments.
This mandatory change has the macro accept an unlimited number of
macro-parameters, but which then must resolve to a single C
expression. This is achieved by squeezing the argument list through a
trivial function call to a static function. By that we ensure that
lists that represent more than one expression (such as `1, 2`) and
empty lists are diagnosed.
---
include/assert.h | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/include/assert.h b/include/assert.h
index 71007a10..034c4aa7 100644
--- a/include/assert.h
+++ b/include/assert.h
@@ -2,10 +2,17 @@
#undef assert
+// Ensure that this version only accepts arguments that resolve to one
+// C expression after preprocessing.
+#ifndef __ASSERT_EXPRESSION
+#define __ASSERT_EXPRESSION(...) __assert_expression(__VA_ARGS__)
+static inline _Bool __assert_expression(_Bool __x) { return __x; }
+#endif
+
#ifdef NDEBUG
-#define assert(x) (void)0
+#define assert(...) (void)0
#else
-#define assert(x) ((void)((x) || (__assert_fail(#x, __FILE__, __LINE__, __func__),0)))
+#define assert(...) ((void)(__ASSERT_EXPRESSION(__VA_ARGS__) || (__assert_fail(#__VA_ARGS__, __FILE__, __LINE__, __func__),0)))
#endif
#if __STDC_VERSION__ >= 201112L && __STDC_VERSION__ < 202311L && !defined(__cplusplus)
--
2.34.1
next prev parent reply other threads:[~2023-05-24 14:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-24 12:54 [musl] [C23 divers headers 00/17] boring header update Jens Gustedt
2023-04-15 13:21 ` [musl] [C23 divers headers 02/17] C23: Add the *_WIDTH macros to stdint.h Jens Gustedt
2023-04-17 9:09 ` [musl] [C23 divers headers 03/17] C23: add call_once to stdlib.h Jens Gustedt
2023-05-24 14:23 ` Rich Felker
2023-04-17 19:52 ` [musl] [C23 divers headers 04/17] C23: add timegm, gmtime_r and localtime_r to time.h in C23 mode Jens Gustedt
2023-04-19 6:38 ` [musl] [C23 divers headers 15/17] C23: add the unreachable macro Jens Gustedt
2023-05-24 14:21 ` Rich Felker
2023-05-24 14:26 ` Jₑₙₛ Gustedt
2023-05-24 14:30 ` Rich Felker
2023-04-19 6:42 ` [musl] [C23 divers headers 16/17] C23: add the nullptr_t type Jens Gustedt
2023-05-24 14:22 ` Rich Felker
2023-05-24 14:29 ` Jₑₙₛ Gustedt
2023-05-24 14:34 ` Rich Felker
2023-05-24 14:42 ` Jₑₙₛ Gustedt
2023-05-24 14:49 ` Rich Felker
2023-05-24 15:24 ` Jₑₙₛ Gustedt
2023-04-19 6:46 ` [musl] [C23 divers headers 17/17] C23: add the __STDC_VERSION_STDDEF_H__ macro Jens Gustedt
2023-04-19 8:16 ` [musl] [C23 divers headers 09/17] C23: update stdbool.h Jens Gustedt
2023-04-19 11:48 ` [musl] [C23 divers headers 10/17] C23: remove the contents of stdalign.h Jens Gustedt
2023-05-24 14:25 ` Rich Felker
2023-04-19 11:59 ` [musl] [C23 divers headers 11/17] C23: remove the static_assert macro Jens Gustedt
2023-04-19 12:17 ` Jens Gustedt [this message]
2023-04-19 12:48 ` [musl] [C23 divers headers 13/17] C23: add the __STDC_VERSION_ASSERT_H__ macro Jens Gustedt
2023-04-19 13:02 ` [musl] [C23 divers headers 06/17] C23: adapt setjmp.h Jens Gustedt
2023-04-19 13:11 ` [musl] [C23 divers headers 07/17] C23: change the noreturn functions in stdlib.h Jens Gustedt
2023-04-19 13:17 ` [musl] [C23 divers headers 08/17] C23: change the noreturn function in threads.h Jens Gustedt
2023-04-19 13:56 ` [musl] [C23 divers headers 14/17] C23: allow va_start to receive only one argument Jens Gustedt
2023-04-21 11:33 ` [musl] [C23 divers headers 01/17] C23: add the WIDTH macros for the standard integer types Jens Gustedt
2023-04-22 20:06 ` [musl] [C23 divers headers 05/17] C23: memccpy, strdup and strndup are now standard C Jens Gustedt
2023-05-31 9:22 [musl] [C23 divers headers 00/17] Jens Gustedt
2023-05-31 9:22 ` [musl] [C23 divers headers 12/17] C23: change the assert macro to ... arguments Jens Gustedt
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