[Bug inline-asm/100785] [9/10/11/12 Regression] ICE: in expand_asm_stmt with "m" and bitfield

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100785

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:b6e4453172e6502318d31517b7d3771b157ae71a

commit r11-8642-gb6e4453172e6502318d31517b7d3771b157ae71a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Jun 21 13:30:42 2021 +0200

    inline-asm: Fix ICE with bitfields in "m" operands [PR100785]

    Bitfields, while they live in memory, aren't something inline-asm can
easily
    operate on.
    For C and "=m" or "+m", we were diagnosing bitfields in the past in the
    FE, where c_mark_addressable had:
          case COMPONENT_REF:
            if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
              {
                error
                  ("cannot take address of bit-field %qD", TREE_OPERAND (x,
1));
                return false;
              }
    but that check got moved in GCC 6 to build_unary_op instead and now we
    emit an error during expansion and ICE afterwards (i.e. error-recovery).
    For "m" it used to be diagnosed in c_mark_addressable too, but since
    GCC 6 it is ice-on-invalid.
    For C++, this was never diagnosed in the FE, but used to be diagnosed
    in the gimplifier and/or during expansion before 4.8.

    The following patch does multiple things:
    1) diagnoses it in the FEs
    2) simplifies during expansion the inline asm if any errors have been
       reported (similarly how e.g. vregs pass if it detects errors on
       inline-asm either deletes them or simplifies to bare minimum -
       just labels), so that we don't have error-recovery ICEs there

    2021-06-11  Jakub Jelinek  <jakub@redhat.com>

            PR inline-asm/100785
    gcc/
            * cfgexpand.c (expand_asm_stmt): If errors are emitted,
            remove all inputs, outputs and clobbers from the asm and
            set template to "".
    gcc/c/
            * c-typeck.c (c_mark_addressable): Diagnose trying to make
            bit-fields addressable.
    gcc/cp/
            * typeck.c (cxx_mark_addressable): Diagnose trying to make
            bit-fields addressable.
    gcc/testsuite/
            * c-c++-common/pr100785.c: New test.

    (cherry picked from commit 644c2cc5f2c09506a7bfef293a7f90efa8d7e5fa)