From 4423ab8fb4650cd0e4906b337ff21ef284893434 Mon Sep 17 00:00:00 2001
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From: Florian Weimer <fweimer@redhat.com>
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Date: Thu, 7 Feb 2019 09:03:02 +0100
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Subject: [PATCH 01/19] array_length: Make usable as a constant expression
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Do not use a statement expression in array_length, so that
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array_length can be used at file scope and as a constant expression.
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Instead, put the _Static_assert into a struct (as a declaration),
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and nest this in the expression using a sizeof expression.
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(cherry picked from commit 8311c83f91a3127ccd2fe684e25bc60c5178d23b)
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Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
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---
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include/array_length.h | 12 ++++++------
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1 file changed, 6 insertions(+), 6 deletions(-)
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diff --git a/include/array_length.h b/include/array_length.h
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index 65f58306..db98a698 100644
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--- a/include/array_length.h
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+++ b/include/array_length.h
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@@ -22,12 +22,12 @@
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/* array_length (VAR) is the number of elements in the array VAR. VAR
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must evaluate to an array, not a pointer. */
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#define array_length(var) \
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- __extension__ ({ \
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- _Static_assert (!__builtin_types_compatible_p \
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- (__typeof (var), __typeof (&(var)[0])), \
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- "argument must be an array"); \
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- sizeof (var) / sizeof ((var)[0]); \
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- })
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+ (sizeof (var) / sizeof ((var)[0]) \
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+ + 0 * sizeof (struct { \
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+ _Static_assert (!__builtin_types_compatible_p \
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+ (__typeof (var), __typeof (&(var)[0])), \
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+ "argument must be an array"); \
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+ }))
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/* array_end (VAR) is a pointer one past the end of the array VAR.
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VAR must evaluate to an array, not a pointer. */
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--
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2.20.1
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