On Mon, Dec 14, 2020 at 5:06 PM Jeff Law <l...@redhat.com> wrote: > > > > On 12/8/20 5:51 AM, H.J. Lu wrote: > > When definitions marked with used attribute and unmarked definitions are > > placed in the section with the same name, switch to a new section if the > > SECTION_RETAIN bit doesn't match. > > > > gcc/ > > > > PR target/98146 > > * output.h (switch_to_section): Add a tree argument, default to > > nullptr. > > * varasm.c (get_section): If the SECTION_RETAIN bit doesn't match, > > return and switch to a new section later. > > (assemble_start_function): Pass decl to switch_to_section. > > (assemble_variable): Likewise. > > (switch_to_section): If the SECTION_RETAIN bit doesn't match, > > switch to a new section. > > > > gcc/testsuite/ > > > > PR target/98146 > > * c-c++-common/attr-used-5.c: New test. > > * c-c++-common/attr-used-6.c: Likewise. > > * c-c++-common/attr-used-7.c: Likewise. > > * c-c++-common/attr-used-8.c: Likewise. > > * c-c++-common/attr-used-9.c: Likewise. > > --- > > gcc/output.h | 2 +- > > gcc/testsuite/c-c++-common/attr-used-5.c | 26 ++++++++++++++++++++ > > gcc/testsuite/c-c++-common/attr-used-6.c | 26 ++++++++++++++++++++ > > gcc/testsuite/c-c++-common/attr-used-7.c | 8 +++++++ > > gcc/testsuite/c-c++-common/attr-used-8.c | 8 +++++++ > > gcc/testsuite/c-c++-common/attr-used-9.c | 28 ++++++++++++++++++++++ > > gcc/varasm.c | 30 ++++++++++++++++++++---- > > 7 files changed, 123 insertions(+), 5 deletions(-) > > create mode 100644 gcc/testsuite/c-c++-common/attr-used-5.c > > create mode 100644 gcc/testsuite/c-c++-common/attr-used-6.c > > create mode 100644 gcc/testsuite/c-c++-common/attr-used-7.c > > create mode 100644 gcc/testsuite/c-c++-common/attr-used-8.c > > create mode 100644 gcc/testsuite/c-c++-common/attr-used-9.c > > > > > > diff --git a/gcc/varasm.c b/gcc/varasm.c > > index 0fac3688828..c5ea29c4e4c 100644 > > --- a/gcc/varasm.c > > +++ b/gcc/varasm.c > > @@ -342,6 +342,11 @@ get_section (const char *name, unsigned int flags, > > tree decl, > > sect->common.flags |= (SECTION_WRITE | SECTION_RELRO); > > return sect; > > } > > + /* If the SECTION_RETAIN bit doesn't match, return and switch > > + to a new section later. */ > > + if ((sect->common.flags & SECTION_RETAIN) > > + != (flags & SECTION_RETAIN)) > > + return sect; > At the least you need to fix the function comment as it would no longer > match the behavior in this case. It also seems to me that having > SECTION_RETAIN be a special case like this just seems wrong. In my > mind there isn't anything fundamentally different with SECTION_RETAIN vs > other symbols that it deserves to be special cased like this.
Any symbols with SHF_XXX can be special, for example SHF_TLS. > Clearly we need to fix something as these bits are causing significant > fallout, but I'm just not sure what the right fix ought to be. > > jeff > -- H.J.
