| Message ID | 20180824210254.GC13632@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | C++ PATCH for c++/87080, ICE with -Wpessimizing-move | expand |
OK. On Sat, Aug 25, 2018 at 7:02 AM, Marek Polacek <polacek@redhat.com> wrote: > The problem in this testcase was that we were calling is_std_move_p from > template context, which breaks in cp_get_fndecl_from_callee. This warning > is not meant to warn while parsing a template, so I think we should apply this. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > 2018-08-24 Marek Polacek <polacek@redhat.com> > > PR c++/87080 > * typeck.c (maybe_warn_pessimizing_move): Do nothing in a template. > > * g++.dg/cpp0x/Wpessimizing-move5.C: New test. > > diff --git gcc/cp/typeck.c gcc/cp/typeck.c > index 122d9dcd4b3..24647e29a55 100644 > --- gcc/cp/typeck.c > +++ gcc/cp/typeck.c > @@ -9192,6 +9192,11 @@ maybe_warn_pessimizing_move (tree retval, tree functype) > if (cxx_dialect < cxx11) > return; > > + /* Wait until instantiation time, since we can't gauge if we should do > + the NRVO until then. */ > + if (processing_template_decl) > + return; > + > /* This is only interesting for class types. */ > if (!CLASS_TYPE_P (functype)) > return; > diff --git gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C > index e69de29bb2d..02ad2113505 100644 > --- gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C > +++ gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C > @@ -0,0 +1,14 @@ > +// PR c++/87080 > +// { dg-do compile { target c++11 } } > +// { dg-options "-Wpessimizing-move" } > + > +struct a { > + template<typename b> a &operator<<(b); > +}; > +a c(); > +template<typename> > +a fn2() > +{ > + int d = 42; > + return c() << d; > +}
diff --git gcc/cp/typeck.c gcc/cp/typeck.c index 122d9dcd4b3..24647e29a55 100644 --- gcc/cp/typeck.c +++ gcc/cp/typeck.c @@ -9192,6 +9192,11 @@ maybe_warn_pessimizing_move (tree retval, tree functype) if (cxx_dialect < cxx11) return; + /* Wait until instantiation time, since we can't gauge if we should do + the NRVO until then. */ + if (processing_template_decl) + return; + /* This is only interesting for class types. */ if (!CLASS_TYPE_P (functype)) return; diff --git gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C index e69de29bb2d..02ad2113505 100644 --- gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C +++ gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C @@ -0,0 +1,14 @@ +// PR c++/87080 +// { dg-do compile { target c++11 } } +// { dg-options "-Wpessimizing-move" } + +struct a { + template<typename b> a &operator<<(b); +}; +a c(); +template<typename> +a fn2() +{ + int d = 42; + return c() << d; +}