From: Victor Stinner <victor.stinner@gmail.com>
Date: Sat, 1 Feb 2014 02:43:58 +0000 (+0100)
Subject: Issue #20354: Fix alignment issue in the tracemalloc module on 64-bit
X-Git-Tag: v3.4.0rc1~139
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=dd382ef8ec8a572f202999ca94ff292722f3d6f6;p=python

Issue #20354: Fix alignment issue in the tracemalloc module on 64-bit
platforms. Bug seen on 64-bit Linux when using "make profile-opt".

Only align the "frame_t" structure on 32-bit when Visual Studio is used. Before
the alignment to 32-bit was applied to the whole file any compiler supporting
"#pragma pack(4)" which includes GCC.
---

diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
index f8ce766251..42dbeaee08 100644
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -61,10 +61,11 @@ static PyThread_type_lock tables_lock;
    architectures: 12 bytes instead of 16. This optimization might produce
    SIGBUS on architectures not supporting unaligned memory accesses (64-bit
    IPS CPU?): on such architecture, the structure must not be packed. */
-#pragma pack(4)
 typedef struct
 #ifdef __GNUC__
 __attribute__((packed))
+#elif defined(_MSC_VER)
+_declspec(align(4))
 #endif
 {
     PyObject *filename;