| From 9e9d94566d39eef3e4606f806aa418bf5534fab9 Mon Sep 17 00:00:00 2001 |
| From: Khem Raj <raj.khem@gmail.com> |
| Date: Sun, 15 Jan 2023 22:04:31 -0800 |
| Subject: [PATCH 1/2] Define alignof using _Alignof when using C11 or newer |
| |
| WG14 N2350 made very clear that it is an UB having type definitions |
| within "offsetof" [1]. This patch enhances the implementation of macro |
| alignof to use builtin "_Alignof" to avoid undefined behavior on |
| when using std=c11 or newer |
| |
| clang 16+ has started to flag this [2] |
| |
| Fixes build when using -std >= gnu11 and using clang16+ |
| |
| Older compilers gcc < 4.9 or clang < 8 has buggy _Alignof even though it |
| may support C11, exclude those compilers too |
| |
| [1] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm |
| [2] https://reviews.llvm.org/D133574 |
| |
| Upstream-Status: Pending |
| |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| --- |
| Misc/md5-coreutils.c | 12 +++++++++++- |
| Misc/sha1.c | 12 +++++++++++- |
| Misc/sha256.c | 12 +++++++++++- |
| Misc/sha512.c | 12 +++++++++++- |
| 4 files changed, 44 insertions(+), 4 deletions(-) |
| |
| diff --git a/Misc/md5-coreutils.c b/Misc/md5-coreutils.c |
| index d6503e02..2ffb6050 100644 |
| --- a/Misc/md5-coreutils.c |
| +++ b/Misc/md5-coreutils.c |
| @@ -154,7 +154,17 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx) |
| if (len >= 64) |
| { |
| #if !_STRING_ARCH_unaligned |
| -# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| + clang versions < 8.0.0 have the same bug. */ |
| +# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| + && !defined __clang__) \ |
| + || (defined __clang__ && __clang_major__ < 8)) |
| +# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +# else |
| +# define alignof(type) _Alignof(type) |
| +# endif |
| # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) |
| if (UNALIGNED_P (buffer)) |
| while (len > 64) |
| diff --git a/Misc/sha1.c b/Misc/sha1.c |
| index 18ceb845..a170efe3 100644 |
| --- a/Misc/sha1.c |
| +++ b/Misc/sha1.c |
| @@ -149,7 +149,17 @@ sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) |
| if (len >= 64) |
| { |
| #if !_STRING_ARCH_unaligned |
| -# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| + clang versions < 8.0.0 have the same bug. */ |
| +# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| + && !defined __clang__) \ |
| + || (defined __clang__ && __clang_major__ < 8)) |
| +# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +# else |
| +# define alignof(type) _Alignof(type) |
| +# endif |
| # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) |
| if (UNALIGNED_P (buffer)) |
| while (len > 64) |
| diff --git a/Misc/sha256.c b/Misc/sha256.c |
| index 68292326..da59e81d 100644 |
| --- a/Misc/sha256.c |
| +++ b/Misc/sha256.c |
| @@ -372,7 +372,17 @@ sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx) |
| if (len >= 64) |
| { |
| #if !_STRING_ARCH_unaligned |
| -# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| + clang versions < 8.0.0 have the same bug. */ |
| +# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| + && !defined __clang__) \ |
| + || (defined __clang__ && __clang_major__ < 8)) |
| +# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +# else |
| +# define alignof(type) _Alignof(type) |
| +# endif |
| # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) |
| if (UNALIGNED_P (buffer)) |
| while (len > 64) |
| diff --git a/Misc/sha512.c b/Misc/sha512.c |
| index db86c659..38e162fc 100644 |
| --- a/Misc/sha512.c |
| +++ b/Misc/sha512.c |
| @@ -190,7 +190,17 @@ sha512_process_bytes (const void *buffer, size_t len, struct sha512_ctx *ctx) |
| if (len >= 128) |
| { |
| #if !_STRING_ARCH_unaligned |
| -# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| + clang versions < 8.0.0 have the same bug. */ |
| +# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| + && !defined __clang__) \ |
| + || (defined __clang__ && __clang_major__ < 8)) |
| +# define alignof(type) offsetof (struct { char c; type x; }, x) |
| +# else |
| +# define alignof(type) _Alignof(type) |
| +# endif |
| # define UNALIGNED_P(p) (((size_t) p) % alignof (uint64_t) != 0) |
| if (UNALIGNED_P (buffer)) |
| while (len > 128) |
| -- |
| 2.39.0 |
| |