1From 9e9d94566d39eef3e4606f806aa418bf5534fab9 Mon Sep 17 00:00:00 2001 2From: Khem Raj <raj.khem@gmail.com> 3Date: Sun, 15 Jan 2023 22:04:31 -0800 4Subject: [PATCH 1/2] Define alignof using _Alignof when using C11 or newer 5 6WG14 N2350 made very clear that it is an UB having type definitions 7within "offsetof" [1]. This patch enhances the implementation of macro 8alignof to use builtin "_Alignof" to avoid undefined behavior on 9when using std=c11 or newer 10 11clang 16+ has started to flag this [2] 12 13Fixes build when using -std >= gnu11 and using clang16+ 14 15Older compilers gcc < 4.9 or clang < 8 has buggy _Alignof even though it 16may support C11, exclude those compilers too 17 18[1] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm 19[2] https://reviews.llvm.org/D133574 20 21Upstream-Status: Pending 22 23Signed-off-by: Khem Raj <raj.khem@gmail.com> 24--- 25 Misc/md5-coreutils.c | 12 +++++++++++- 26 Misc/sha1.c | 12 +++++++++++- 27 Misc/sha256.c | 12 +++++++++++- 28 Misc/sha512.c | 12 +++++++++++- 29 4 files changed, 44 insertions(+), 4 deletions(-) 30 31diff --git a/Misc/md5-coreutils.c b/Misc/md5-coreutils.c 32index d6503e02..2ffb6050 100644 33--- a/Misc/md5-coreutils.c 34+++ b/Misc/md5-coreutils.c 35@@ -154,7 +154,17 @@ md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx) 36 if (len >= 64) 37 { 38 #if !_STRING_ARCH_unaligned 39-# define alignof(type) offsetof (struct { char c; type x; }, x) 40+/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 41+ <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. 42+ clang versions < 8.0.0 have the same bug. */ 43+# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ 44+ || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ 45+ && !defined __clang__) \ 46+ || (defined __clang__ && __clang_major__ < 8)) 47+# define alignof(type) offsetof (struct { char c; type x; }, x) 48+# else 49+# define alignof(type) _Alignof(type) 50+# endif 51 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) 52 if (UNALIGNED_P (buffer)) 53 while (len > 64) 54diff --git a/Misc/sha1.c b/Misc/sha1.c 55index 18ceb845..a170efe3 100644 56--- a/Misc/sha1.c 57+++ b/Misc/sha1.c 58@@ -149,7 +149,17 @@ sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) 59 if (len >= 64) 60 { 61 #if !_STRING_ARCH_unaligned 62-# define alignof(type) offsetof (struct { char c; type x; }, x) 63+/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 64+ <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. 65+ clang versions < 8.0.0 have the same bug. */ 66+# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ 67+ || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ 68+ && !defined __clang__) \ 69+ || (defined __clang__ && __clang_major__ < 8)) 70+# define alignof(type) offsetof (struct { char c; type x; }, x) 71+# else 72+# define alignof(type) _Alignof(type) 73+# endif 74 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) 75 if (UNALIGNED_P (buffer)) 76 while (len > 64) 77diff --git a/Misc/sha256.c b/Misc/sha256.c 78index 68292326..da59e81d 100644 79--- a/Misc/sha256.c 80+++ b/Misc/sha256.c 81@@ -372,7 +372,17 @@ sha256_process_bytes (const void *buffer, size_t len, struct sha256_ctx *ctx) 82 if (len >= 64) 83 { 84 #if !_STRING_ARCH_unaligned 85-# define alignof(type) offsetof (struct { char c; type x; }, x) 86+/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 87+ <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. 88+ clang versions < 8.0.0 have the same bug. */ 89+# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ 90+ || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ 91+ && !defined __clang__) \ 92+ || (defined __clang__ && __clang_major__ < 8)) 93+# define alignof(type) offsetof (struct { char c; type x; }, x) 94+# else 95+# define alignof(type) _Alignof(type) 96+# endif 97 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint32_t) != 0) 98 if (UNALIGNED_P (buffer)) 99 while (len > 64) 100diff --git a/Misc/sha512.c b/Misc/sha512.c 101index db86c659..38e162fc 100644 102--- a/Misc/sha512.c 103+++ b/Misc/sha512.c 104@@ -190,7 +190,17 @@ sha512_process_bytes (const void *buffer, size_t len, struct sha512_ctx *ctx) 105 if (len >= 128) 106 { 107 #if !_STRING_ARCH_unaligned 108-# define alignof(type) offsetof (struct { char c; type x; }, x) 109+/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 110+ <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. 111+ clang versions < 8.0.0 have the same bug. */ 112+# if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ 113+ || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ 114+ && !defined __clang__) \ 115+ || (defined __clang__ && __clang_major__ < 8)) 116+# define alignof(type) offsetof (struct { char c; type x; }, x) 117+# else 118+# define alignof(type) _Alignof(type) 119+# endif 120 # define UNALIGNED_P(p) (((size_t) p) % alignof (uint64_t) != 0) 121 if (UNALIGNED_P (buffer)) 122 while (len > 128) 123-- 1242.39.0 125 126