Andrew Geissler | c5535c9 | 2023-01-27 16:10:19 -0600 | [diff] [blame] | 1 | From f9ac08a0fea543d68b2dba540093bd079e50be47 Mon Sep 17 00:00:00 2001 |
| 2 | From: Khem Raj <raj.khem@gmail.com> |
| 3 | Date: Sun, 15 Jan 2023 15:49:09 -0800 |
| 4 | Subject: [PATCH] Define _ALIGN using _Alignof when using C11 or newer |
| 5 | |
| 6 | WG14 N2350 made very clear that it is an UB having type definitions |
| 7 | within "offsetof" [1]. This patch enhances the implementation of macro |
| 8 | _ALIGN to use builtin "_Alignof" to avoid undefined behavior on |
| 9 | when using std=c11 or newer |
| 10 | |
| 11 | clang 16+ has started to flag this [2] |
| 12 | |
| 13 | Fixes build when using -std >= gnu11 and using clang16+ |
| 14 | |
| 15 | Older compilers gcc < 4.9 or clang < 8 has buggy _Alignof even though it |
| 16 | may 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 | |
| 21 | Upstream-Status: Submitted [https://github.com/numpy/numpy/pull/23016] |
| 22 | Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| 23 | --- |
| 24 | numpy/core/src/multiarray/arraytypes.c.src | 13 +++++++++++-- |
| 25 | numpy/core/src/multiarray/common.h | 12 +++++++++++- |
| 26 | 2 files changed, 22 insertions(+), 3 deletions(-) |
| 27 | |
| 28 | diff --git a/numpy/core/src/multiarray/arraytypes.c.src b/numpy/core/src/multiarray/arraytypes.c.src |
| 29 | index c03d09784..683917220 100644 |
| 30 | --- a/numpy/core/src/multiarray/arraytypes.c.src |
| 31 | +++ b/numpy/core/src/multiarray/arraytypes.c.src |
| 32 | @@ -224,8 +224,17 @@ MyPyLong_AsUnsigned@Type@(PyObject *obj) |
| 33 | ** GETITEM AND SETITEM ** |
| 34 | ***************************************************************************** |
| 35 | */ |
| 36 | - |
| 37 | -#define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| 38 | +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| 39 | + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| 40 | + clang versions < 8.0.0 have the same bug. */ |
| 41 | +#if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| 42 | + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| 43 | + && !defined __clang__) \ |
| 44 | + || (defined __clang__ && __clang_major__ < 8)) |
| 45 | +# define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| 46 | +#else |
| 47 | +# define _ALIGN(type) _Alignof(type) |
| 48 | +#endif |
| 49 | /* |
| 50 | * Disable harmless compiler warning "4116: unnamed type definition in |
| 51 | * parentheses" which is caused by the _ALIGN macro. |
| 52 | diff --git a/numpy/core/src/multiarray/common.h b/numpy/core/src/multiarray/common.h |
| 53 | index 3de8c842d..d01074c45 100644 |
| 54 | --- a/numpy/core/src/multiarray/common.h |
| 55 | +++ b/numpy/core/src/multiarray/common.h |
| 56 | @@ -178,7 +178,17 @@ check_and_adjust_axis(int *axis, int ndim) |
| 57 | } |
| 58 | |
| 59 | /* used for some alignment checks */ |
| 60 | -#define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| 61 | +/* GCC releases before GCC 4.9 had a bug in _Alignof. See GCC bug 52023 |
| 62 | + <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. |
| 63 | + clang versions < 8.0.0 have the same bug. */ |
| 64 | +#if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \ |
| 65 | + || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \ |
| 66 | + && !defined __clang__) \ |
| 67 | + || (defined __clang__ && __clang_major__ < 8)) |
| 68 | +# define _ALIGN(type) offsetof(struct {char c; type v;}, v) |
| 69 | +#else |
| 70 | +# define _ALIGN(type) _Alignof(type) |
| 71 | +#endif |
| 72 | #define _UINT_ALIGN(type) npy_uint_alignment(sizeof(type)) |
| 73 | /* |
| 74 | * Disable harmless compiler warning "4116: unnamed type definition in |
| 75 | -- |
| 76 | 2.39.0 |
| 77 | |