Mercurial > hg > nginx
changeset 3396:2c5e269d0608
fix building by gcc 4.x with -O2/3/s in some Linux distributions:
dereferencing type-punned pointer will break strict-aliasing rules
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Tue, 22 Dec 2009 15:29:56 +0000 |
parents | 4e15548b29d4 |
children | 3b2a8a0dca8e |
files | src/os/unix/ngx_channel.c |
diffstat | 1 files changed, 15 insertions(+), 2 deletions(-) [+] |
line wrap: on
line diff
--- a/src/os/unix/ngx_channel.c Tue Dec 22 15:15:45 2009 +0000 +++ b/src/os/unix/ngx_channel.c Tue Dec 22 15:29:56 2009 +0000 @@ -36,7 +36,18 @@ cmsg.cm.cmsg_len = CMSG_LEN(sizeof(int)); cmsg.cm.cmsg_level = SOL_SOCKET; cmsg.cm.cmsg_type = SCM_RIGHTS; - *(int *) CMSG_DATA(&cmsg.cm) = ch->fd; + + /* + * We have to use ngx_memcpy() instead of simple + * *(int *) CMSG_DATA(&cmsg.cm) = ch->fd; + * because some gcc 4.4 with -O2/3/s optimization issues the warning: + * dereferencing type-punned pointer will break strict-aliasing rules + * + * Fortunately, gcc with -O1 compiles this ngx_memcpy() + * in the same simple assigment as in the code above + */ + + ngx_memcpy(CMSG_DATA(&cmsg.cm), &ch->fd, sizeof(int)); } msg.msg_flags = 0; @@ -153,7 +164,9 @@ return NGX_ERROR; } - ch->fd = *(int *) CMSG_DATA(&cmsg.cm); + /* ch->fd = *(int *) CMSG_DATA(&cmsg.cm); */ + + ngx_memcpy(&ch->fd, CMSG_DATA(&cmsg.cm), sizeof(int)); } if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) {