From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 5/6] bug.h: sync BUILD_BUG stuff with Linux 4.13
Date: Wed, 13 Sep 2017 20:45:05 +0900 [thread overview]
Message-ID: <1505303106-9780-6-git-send-email-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <1505303106-9780-1-git-send-email-yamada.masahiro@socionext.com>
As commit 84b8bf6d5d2a ("bug.h: move BUILD_BUG_* defines to
include/linux/bug.h") noted, include/linux/bug.h was locally
modified for U-Boot because the name conflict of error() caused
build errors at that time.
Now error() is gone, so we can fully sync BUILD_BUG* with Linux.
These macros are just compile-time utilities. Nothing is related
to platform code, so it makes sense to simply copy Linux's ones.
Please note Linux split BUILD_BUG stuff out into <linux/build_bug.h>
by commit bc6245e5efd7. Let's follow it.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
include/linux/bug.h | 51 +---------------------------
include/linux/build_bug.h | 84 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/compiler.h | 6 +++-
3 files changed, 90 insertions(+), 51 deletions(-)
create mode 100644 include/linux/build_bug.h
diff --git a/include/linux/bug.h b/include/linux/bug.h
index 920e379..133544c 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -1,55 +1,6 @@
#ifndef _LINUX_BUG_H
#define _LINUX_BUG_H
-#include <linux/compiler.h>
-
-#ifdef __CHECKER__
-#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
-#define BUILD_BUG_ON_ZERO(e) (0)
-#define BUILD_BUG_ON_NULL(e) ((void*)0)
-#define BUILD_BUG_ON_INVALID(e) (0)
-#define BUILD_BUG_ON(condition) (0)
-#define BUILD_BUG() (0)
-#else /* __CHECKER__ */
-
-/* Force a compilation error if a constant expression is not a power of 2 */
-#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
- BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
-
-/* Force a compilation error if condition is true, but also produce a
- result (of value 0 and type size_t), so the expression can be used
- e.g. in a structure initializer (or where-ever else comma expressions
- aren't permitted). */
-#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
-#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
-
-/*
- * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
- * expression but avoids the generation of any code, even if that expression
- * has side-effects.
- */
-#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
-
-/**
- * BUILD_BUG_ON - break compile if a condition is true.
- * @condition: the condition which the compiler should know is false.
- *
- * If you have some code which relies on certain constants being equal, or
- * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
- * detect if someone changes it.
- *
- * The implementation uses gcc's reluctance to create a negative array, but gcc
- * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
- * inline functions). Luckily, in 4.3 they added the "error" function
- * attribute just for this type of case. Thus, we use a negative sized array
- * (should always create an error on gcc versions older than 4.4) and then call
- * an undefined function with the error attribute (should always create an
- * error on gcc 4.3 and later). If for some reason, neither creates a
- * compile-time error, we'll still have a link-time error, which is harder to
- * track down.
- */
-#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
-
-#endif /* __CHECKER__ */
+#include <linux/build_bug.h>
#endif /* _LINUX_BUG_H */
diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h
new file mode 100644
index 0000000..b7d22d6
--- /dev/null
+++ b/include/linux/build_bug.h
@@ -0,0 +1,84 @@
+#ifndef _LINUX_BUILD_BUG_H
+#define _LINUX_BUILD_BUG_H
+
+#include <linux/compiler.h>
+
+#ifdef __CHECKER__
+#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
+#define BUILD_BUG_ON_ZERO(e) (0)
+#define BUILD_BUG_ON_NULL(e) ((void *)0)
+#define BUILD_BUG_ON_INVALID(e) (0)
+#define BUILD_BUG_ON_MSG(cond, msg) (0)
+#define BUILD_BUG_ON(condition) (0)
+#define BUILD_BUG() (0)
+#else /* __CHECKER__ */
+
+/* Force a compilation error if a constant expression is not a power of 2 */
+#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
+ BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
+ BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
+
+/*
+ * Force a compilation error if condition is true, but also produce a
+ * result (of value 0 and type size_t), so the expression can be used
+ * e.g. in a structure initializer (or where-ever else comma expressions
+ * aren't permitted).
+ */
+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:(-!!(e)); }))
+
+/*
+ * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
+ * expression but avoids the generation of any code, even if that expression
+ * has side-effects.
+ */
+#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
+
+/**
+ * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
+ * error message.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * See BUILD_BUG_ON for description.
+ */
+#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
+
+/**
+ * BUILD_BUG_ON - break compile if a condition is true.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * If you have some code which relies on certain constants being equal, or
+ * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
+ * detect if someone changes it.
+ *
+ * The implementation uses gcc's reluctance to create a negative array, but gcc
+ * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
+ * inline functions). Luckily, in 4.3 they added the "error" function
+ * attribute just for this type of case. Thus, we use a negative sized array
+ * (should always create an error on gcc versions older than 4.4) and then call
+ * an undefined function with the error attribute (should always create an
+ * error on gcc 4.3 and later). If for some reason, neither creates a
+ * compile-time error, we'll still have a link-time error, which is harder to
+ * track down.
+ */
+#ifndef __OPTIMIZE__
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+#else
+#define BUILD_BUG_ON(condition) \
+ BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
+#endif
+
+/**
+ * BUILD_BUG - break compile if used.
+ *
+ * If you have some code that you expect the compiler to eliminate at
+ * build time, you should use BUILD_BUG to detect if it is
+ * unexpectedly used.
+ */
+#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
+
+#endif /* __CHECKER__ */
+
+#endif /* _LINUX_BUILD_BUG_H */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 020ad16..0ea6c8f 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -476,7 +476,8 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
# define __compiletime_error_fallback(condition) do { } while (0)
#endif
-#define __compiletime_assert(condition, msg, prefix, suffix) \
+#ifdef __OPTIMIZE__
+# define __compiletime_assert(condition, msg, prefix, suffix) \
do { \
bool __cond = !(condition); \
extern void prefix ## suffix(void) __compiletime_error(msg); \
@@ -484,6 +485,9 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
prefix ## suffix(); \
__compiletime_error_fallback(__cond); \
} while (0)
+#else
+# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
+#endif
#define _compiletime_assert(condition, msg, prefix, suffix) \
__compiletime_assert(condition, msg, prefix, suffix)
--
2.7.4
next prev parent reply other threads:[~2017-09-13 11:45 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-13 11:45 [U-Boot] [PATCH 0/6] Sync and consolidate Linux-derived printk, BUILD_BUG, BUG, WARN, etc Masahiro Yamada
2017-09-13 11:45 ` [U-Boot] [PATCH 1/6] printk: collect printk stuff into <linux/printk.h> Masahiro Yamada
2017-09-13 11:45 ` [U-Boot] [PATCH 2/6] treewide: replace with error() with pr_err() Masahiro Yamada
2017-09-17 17:52 ` Simon Glass
2017-09-13 11:45 ` [U-Boot] [PATCH 3/6] common.h: remove error() Masahiro Yamada
2017-09-13 11:45 ` [U-Boot] [PATCH 4/6] vsprintf.h: include <linux/types.h> Masahiro Yamada
2017-09-13 11:45 ` Masahiro Yamada [this message]
2017-09-13 11:45 ` [U-Boot] [PATCH 6/6] bug.h: move runtime BUG/WARN macros into <linux/bug.h> Masahiro Yamada
2017-09-14 2:08 ` [U-Boot] [PATCH 0/6] Sync and consolidate Linux-derived printk, BUILD_BUG, BUG, WARN, etc Masahiro Yamada
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1505303106-9780-6-git-send-email-yamada.masahiro@socionext.com \
--to=yamada.masahiro@socionext.com \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.