| Message ID | 20170103224255.GB21933@tucnak |
|---|---|
| State | New |
| Headers | show |
OK. On Tue, Jan 3, 2017 at 5:42 PM, Jakub Jelinek <jakub@redhat.com> wrote: > Hi! > > cp_lexer_new_from_tokens creates lexer that has NULL lexer->buffer, > calling lexer->buffer->address () therefore is UB (diagnosed by > --with-boot-config=bootstrap-ubsan). > > The following patch fixes this, or Markus offered > gcc_assert (!lexer->buffer || tp != lexer->buffer->address ()); > instead. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk (or do you prefer Markus' version)? > > 2017-01-03 Jakub Jelinek <jakub@redhat.com> > > PR c++/71182 > * parser.c (cp_lexer_previous_token): Use vec_safe_address in the > assertion, as lexer->buffer may be NULL. > > * g++.dg/cpp0x/pr71182.C: New test. > > --- gcc/cp/parser.c.jj 2017-01-03 09:58:13.000000000 +0100 > +++ gcc/cp/parser.c 2017-01-03 11:39:56.940595981 +0100 > @@ -766,7 +766,7 @@ cp_lexer_previous_token (cp_lexer *lexer > /* Skip past purged tokens. */ > while (tp->purged_p) > { > - gcc_assert (tp != lexer->buffer->address ()); > + gcc_assert (tp != vec_safe_address (lexer->buffer)); > tp--; > } > > --- gcc/testsuite/g++.dg/cpp0x/pr71182.C.jj 2017-01-03 11:44:19.400246340 +0100 > +++ gcc/testsuite/g++.dg/cpp0x/pr71182.C 2017-01-03 11:44:04.795432815 +0100 > @@ -0,0 +1,12 @@ > +// PR c++/71182 > +// { dg-do compile { target c++11 } } > + > +class A { > + template <typename> void As(); > +}; > +template <typename T> class B : A { > + void f() { > + A *g ; > + g ? g->As<T>() : nullptr; > + } > +}; > > Jakub
--- gcc/cp/parser.c.jj 2017-01-03 09:58:13.000000000 +0100 +++ gcc/cp/parser.c 2017-01-03 11:39:56.940595981 +0100 @@ -766,7 +766,7 @@ cp_lexer_previous_token (cp_lexer *lexer /* Skip past purged tokens. */ while (tp->purged_p) { - gcc_assert (tp != lexer->buffer->address ()); + gcc_assert (tp != vec_safe_address (lexer->buffer)); tp--; } --- gcc/testsuite/g++.dg/cpp0x/pr71182.C.jj 2017-01-03 11:44:19.400246340 +0100 +++ gcc/testsuite/g++.dg/cpp0x/pr71182.C 2017-01-03 11:44:04.795432815 +0100 @@ -0,0 +1,12 @@ +// PR c++/71182 +// { dg-do compile { target c++11 } } + +class A { + template <typename> void As(); +}; +template <typename T> class B : A { + void f() { + A *g ; + g ? g->As<T>() : nullptr; + } +};
Hi! cp_lexer_new_from_tokens creates lexer that has NULL lexer->buffer, calling lexer->buffer->address () therefore is UB (diagnosed by --with-boot-config=bootstrap-ubsan). The following patch fixes this, or Markus offered gcc_assert (!lexer->buffer || tp != lexer->buffer->address ()); instead. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk (or do you prefer Markus' version)? 2017-01-03 Jakub Jelinek <jakub@redhat.com> PR c++/71182 * parser.c (cp_lexer_previous_token): Use vec_safe_address in the assertion, as lexer->buffer may be NULL. * g++.dg/cpp0x/pr71182.C: New test. Jakub