| Message ID | e2e8e82b-dec3-5b9e-2766-74f61b94ff83@gmail.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Mar 15, 2017 at 6:59 PM, Martin Sebor <msebor@gmail.com> wrote: > In bug 52477 - Wrong initialization order? attribute constructor > vs static data access, the reporter expects C++ objects with static > storage duration to have their ctors called in the same order as > those of functions declared with attribute constructor interleaved > with them. > > In his comment on the bug Richard opines that relying on the order > is undefined. The attached patch updates the manual to make this > clear. I disagree with that comment, and have added one of my own, but I think your patch is appropriate for GCC 7 since we aren't going to fix it in this release. Jason
On 03/15/2017 10:49 PM, Jason Merrill wrote: > On Wed, Mar 15, 2017 at 6:59 PM, Martin Sebor <msebor@gmail.com> wrote: >> In bug 52477 - Wrong initialization order? attribute constructor >> vs static data access, the reporter expects C++ objects with static >> storage duration to have their ctors called in the same order as >> those of functions declared with attribute constructor interleaved >> with them. >> >> In his comment on the bug Richard opines that relying on the order >> is undefined. The attached patch updates the manual to make this >> clear. > > I disagree with that comment, and have added one of my own, but I > think your patch is appropriate for GCC 7 since we aren't going to fix > it in this release. Okay, thanks. In that case I should probably word it slightly differently. I've added "at present" below to imply (hint) that this might change in the future. I'll go with this unless you have a different suggestion. However, <ins>at present, </ins>the order in which constructors for C++ objects with static storage duration and functions decorated with attribute @code{constructor} are invoked is unspecified. In mixed declarations, attribute @code{init_priority} can be used to impose a specific ordering. Martin
On Thu, Mar 16, 2017 at 11:22 AM, Martin Sebor <msebor@gmail.com> wrote: > On 03/15/2017 10:49 PM, Jason Merrill wrote: >> >> On Wed, Mar 15, 2017 at 6:59 PM, Martin Sebor <msebor@gmail.com> wrote: >>> >>> In bug 52477 - Wrong initialization order? attribute constructor >>> vs static data access, the reporter expects C++ objects with static >>> storage duration to have their ctors called in the same order as >>> those of functions declared with attribute constructor interleaved >>> with them. >>> >>> In his comment on the bug Richard opines that relying on the order >>> is undefined. The attached patch updates the manual to make this >>> clear. >> >> I disagree with that comment, and have added one of my own, but I >> think your patch is appropriate for GCC 7 since we aren't going to fix >> it in this release. > > Okay, thanks. In that case I should probably word it slightly > differently. I've added "at present" below to imply (hint) that > this might change in the future. I'll go with this unless you > have a different suggestion. > > However, <ins>at present, </ins>the order in which constructors > for C++ objects with static storage duration and functions decorated > with attribute @code{constructor} are invoked is unspecified. In > mixed declarations, attribute @code{init_priority} can be used to > impose a specific ordering. Sounds good. Jason
PR c++/52477 - Wrong initialization order? __attribute__((constructor)) vs static data access gcc/ChangeLog: PR c++/52477 * doc/extend.texi (attribute constructor): Mention order of C++ ctors. diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 143a7b7..159f1be 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -2510,7 +2510,11 @@ if you have a constructor that allocates a resource and a destructor that deallocates the same resource, both functions typically have the same priority. The priorities for constructor and destructor functions are the same as those specified for namespace-scope C++ -objects (@pxref{C++ Attributes}). +objects (@pxref{C++ Attributes}). However, the order in which +constructors for C++ objects with static storage duration and functions +decorated with attribute @code{constructor} are invoked is unspecified. +In mixed declarations, attribute @code{init_priority} can be used to +impose a specific ordering. @item deprecated @itemx deprecated (@var{msg})