| Message ID | 87lh7cv28r.fsf@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 01/26/2016 07:34 AM, Nick Clifton wrote: > Hi Guys, > > The patch below is offered as a fix for PR 66655. In testing it > appears that the patch does work, and does not break building > libstdc++-v3 for cygwin or mingw. (Unlike the earlier version...) > > Due to my brain being so small, I have already checked the patch in, > without receiving proper authorisation. I apologise for this. If the > patch does prove suitable and is approved today, then I will leave it > in. Otherwise I will revert the change and wait for proper approval. > > The patch itself is also slightly dubious in that I am not sure if I > have all the correct terms in the if-statement. I was going for > minimal impact on the current code, so I went for a set of selectors > that matched the testcase for PR 66655, but nothing else. In > particular I did not check to see if a similar problem exists for > methods or virtual functions. > > My theory was that if does turn out that these kinds of functions can > also trigger this kind of bug, then the patch could be extended > later. Plus a new bug report is likely to include a new testcase that > can be added to the testsuite. > > So ... OK to apply ? > > Cheers > Nick > > gcc/ChangeLog > 2016-01-26 Nick Clifton <nickc@redhat.com> > > PR target/66655 > * config/i386/winnt.c (i386_pe_binds_local_p): If a function has > been marked as DECL_ONE_ONLY but we do not the means to make it > so, then do not allow it to bind locally. This is OK. Note that in general we're trying to get away from this kind of #if[n]def checking and instead use if (whatever). The motivation is to avoid conditionally compiled code as much as possible. That avoids lots of silly problems that we have to deal with far too often (like variables/arguments that are only used inside conditionally compiled code and similar stuff. MAKE_DECL_ONE_ONLY is used elsewhere to create conditionally compiled code and we're in stage4, so I'm not going to insist on converting it right now. And FWIW, with Kai leaving, we don't really have a cygwin/mingw maintainer. So I really appreciate the effort you and others have put forth to addressing these issues -- if you didn't put forth that effort I suspect the windows based toolchains would probably be fairly broken for gcc-6. jeff
Index: gcc/config/i386/winnt.c =================================================================== --- gcc/config/i386/winnt.c (revision 232784) +++ gcc/config/i386/winnt.c (working copy) @@ -341,6 +341,20 @@ && TREE_PUBLIC (exp) && DECL_EXTERNAL (exp)) return true; + +#ifndef MAKE_DECL_ONE_ONLY + /* PR target/66655: If a function has been marked as DECL_ONE_ONLY + but we do not the means to make it so, then do not allow it to + bind locally. */ + if (DECL_P (exp) + && TREE_CODE (exp) == FUNCTION_DECL + && TREE_PUBLIC (exp) + && DECL_ONE_ONLY (exp) + && ! DECL_EXTERNAL (exp) + && DECL_DECLARED_INLINE_P (exp)) + return false; +#endif + return default_binds_local_p_1 (exp, 0); }