On Wed, Feb 23, 2022 at 11:46 PM Alexandre Oliva via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
>
> In def_cfa_0, we may set the 2nd operand's dw_cfi_cfa_loc to NULL, but
> then cfi_oprnd_equal_p calls cfa_equal_p with a NULL dw_cfa_location*.
> This patch aranges for us to tolerate NULL dw_cfi_cfa_loc.
>
> Regstrapped on x86_64-linux-gnu. Ok to install?
OK.
Richard.
>
> for gcc/ChangeLog
>
> PR middle-end/104540
> * dwarf2cfi.cc (cfi_oprnd_equal_p): Cope with NULL
> dw_cfi_cfa_loc.
>
> for gcc/testsuite/ChangeLog
>
> PR middle-end/104540
> * g++.dg/PR104540.C: New.
> ---
> gcc/dwarf2cfi.cc | 3 +++
> gcc/testsuite/g++.dg/pr104540.C | 21 +++++++++++++++++++++
> 2 files changed, 24 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/pr104540.C
>
> diff --git a/gcc/dwarf2cfi.cc b/gcc/dwarf2cfi.cc
> index 9ca97d7a3bf56..ab7c5cc5b27b5 100644
> --- a/gcc/dwarf2cfi.cc
> +++ b/gcc/dwarf2cfi.cc
> @@ -788,6 +788,9 @@ cfi_oprnd_equal_p (enum dw_cfi_oprnd_type t, dw_cfi_oprnd
> *a, dw_cfi_oprnd *b)
> case dw_cfi_oprnd_loc:
> return loc_descr_equal_p (a->dw_cfi_loc, b->dw_cfi_loc);
> case dw_cfi_oprnd_cfa_loc:
> + /* If any of them is NULL, don't dereference either. */
> + if (!a->dw_cfi_cfa_loc || !b->dw_cfi_cfa_loc)
> + return a->dw_cfi_cfa_loc == b->dw_cfi_cfa_loc;
> return cfa_equal_p (a->dw_cfi_cfa_loc, b->dw_cfi_cfa_loc);
> }
> gcc_unreachable ();
> diff --git a/gcc/testsuite/g++.dg/pr104540.C b/gcc/testsuite/g++.dg/pr104540.C
> new file mode 100644
> index 0000000000000..a86ecbfd088c3
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr104540.C
> @@ -0,0 +1,21 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fharden-conditional-branches -mforce-drap
> -mstackrealign --param=max-grow-copy-bb-insns=125" } */
> +
> +char c;
> +int i;
> +
> +void bar(int);
> +
> +struct S {
> + int mi;
> + long ml;
> + S(int);
> +};
> +
> +
> +void foo() {
> + int s = c == 0 ? 1 : 2;
> + bar(s);
> + if (i)
> + S s(0);
> +}
>
>
> --
> Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
> Free Software Activist GNU Toolchain Engineer
> Disinformation flourishes because many people care deeply about injustice
> but very few check the facts. Ask me about <https://stallmansupport.org>
