| From f9ac08a0fea543d68b2dba540093bd079e50be47 Mon Sep 17 00:00:00 2001 |
| From: Khem Raj <raj.khem@gmail.com> |
| Date: Sun, 15 Jan 2023 15:49:09 -0800 |
| Subject: [PATCH] Define _ALIGN 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 |
| _ALIGN 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: Submitted [https://github.com/numpy/numpy/pull/23016] |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| --- |
| numpy/core/src/multiarray/arraytypes.c.src | 13 +++++++++++-- |
| numpy/core/src/multiarray/common.h | 12 +++++++++++- |
| 2 files changed, 22 insertions(+), 3 deletions(-) |
| |
| diff --git a/numpy/core/src/multiarray/arraytypes.c.src b/numpy/core/src/multiarray/arraytypes.c.src |
| index c03d09784..683917220 100644 |
| --- a/numpy/core/src/multiarray/arraytypes.c.src |
| +++ b/numpy/core/src/multiarray/arraytypes.c.src |
| @@ -224,8 +224,17 @@ MyPyLong_AsUnsigned@Type@(PyObject *obj) |
| ** GETITEM AND SETITEM ** |
| ***************************************************************************** |
| */ |
| - |
| -#define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| +/* 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 _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| +#else |
| +# define _ALIGN(type) _Alignof(type) |
| +#endif |
| /* |
| * Disable harmless compiler warning "4116: unnamed type definition in |
| * parentheses" which is caused by the _ALIGN macro. |
| diff --git a/numpy/core/src/multiarray/common.h b/numpy/core/src/multiarray/common.h |
| index 3de8c842d..d01074c45 100644 |
| --- a/numpy/core/src/multiarray/common.h |
| +++ b/numpy/core/src/multiarray/common.h |
| @@ -178,7 +178,17 @@ check_and_adjust_axis(int *axis, int ndim) |
| } |
| |
| /* used for some alignment checks */ |
| -#define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| +/* 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 _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| +#else |
| +# define _ALIGN(type) _Alignof(type) |
| +#endif |
| #define _UINT_ALIGN(type) npy_uint_alignment(sizeof(type)) |
| /* |
| * Disable harmless compiler warning "4116: unnamed type definition in |
| -- |
| 2.39.0 |
| |