| Message ID | 20170309223231.GH3172@redhat.com |
|---|---|
| State | New |
| Headers | show |
Yep, I just checked in that change. On Thu, Mar 9, 2017 at 5:32 PM, Marek Polacek <polacek@redhat.com> wrote: > On Thu, Mar 09, 2017 at 10:06:53PM +0100, Jakub Jelinek wrote: >> On Thu, Mar 09, 2017 at 12:00:48AM +0100, Marek Polacek wrote: >> > We crash on an assert in strip_typedefs, because we find ourselves in a >> > scenario where RESULT, the main variant of a struct, was modified in >> > finalize_record_size (its TYPE_ALIGN changed), but its variants (T in >> > strip_typedefs) weren't fixed-up yet; that will happen slightly later in >> > finalize_type_size. So there's a discrepancy that confuses the code. >> > >> > This patch implements what Jason suggested to me on IRC, i.e., skip the >> > attribute handling if RESULT is complete and T isn't. >> > >> > Bootstrapped/regtested on x86_64-linux, ok for trunk? >> > >> > 2017-03-08 Marek Polacek <polacek@redhat.com> >> > >> > PR c++/79900 - ICE in strip_typedefs >> > * tree.c (strip_typedefs): Skip the attribute handling if T is >> > a variant type which hasn't been updated yet. >> > >> > * g++.dg/warn/Wpadded-1.C: New test. >> > >> > diff --git gcc/testsuite/g++.dg/warn/Wpadded-1.C gcc/testsuite/g++.dg/warn/Wpadded-1.C >> > index e69de29..b3f0581 100644 >> > --- gcc/testsuite/g++.dg/warn/Wpadded-1.C >> > +++ gcc/testsuite/g++.dg/warn/Wpadded-1.C >> > @@ -0,0 +1,22 @@ >> > +// PR c++/79900 - ICE in strip_typedefs >> > +// { dg-do compile } >> > +// { dg-options "-Wpadded" } >> > + >> > +template <class> struct A; >> > +template <typename> struct B { // { dg-warning "padding struct size to alignment boundary" } >> > + long _M_off; >> > + int _M_state; >> > +}; >> >> This fails on i686-linux, there is obviously no padding of struct size to >> alignment boundary in that case. > > Ah, of course... > >> Can't _M_state be e.g. char, then it would work at least on all targets >> where long has alignment of at least 2 (that can be all of them)? >> Perhaps also make _M_off long long or add a double or long double field. > > Like this? Passes with -m32. > > 2017-03-09 Marek Polacek <polacek@redhat.com> > > * g++.dg/warn/Wpadded-1.C: Change types of struct B fields. > > diff --git gcc/testsuite/g++.dg/warn/Wpadded-1.C gcc/testsuite/g++.dg/warn/Wpadded-1.C > index b3f0581..af375a4 100644 > --- gcc/testsuite/g++.dg/warn/Wpadded-1.C > +++ gcc/testsuite/g++.dg/warn/Wpadded-1.C > @@ -4,8 +4,8 @@ > > template <class> struct A; > template <typename> struct B { // { dg-warning "padding struct size to alignment boundary" } > - long _M_off; > - int _M_state; > + long long _M_off; > + char _M_state; > }; > template <> struct A<char> { typedef B<int> pos_type; }; > enum _Ios_Openmode {}; > > Marek
diff --git gcc/testsuite/g++.dg/warn/Wpadded-1.C gcc/testsuite/g++.dg/warn/Wpadded-1.C index b3f0581..af375a4 100644 --- gcc/testsuite/g++.dg/warn/Wpadded-1.C +++ gcc/testsuite/g++.dg/warn/Wpadded-1.C @@ -4,8 +4,8 @@ template <class> struct A; template <typename> struct B { // { dg-warning "padding struct size to alignment boundary" } - long _M_off; - int _M_state; + long long _M_off; + char _M_state; }; template <> struct A<char> { typedef B<int> pos_type; }; enum _Ios_Openmode {};