On Sat, Oct 14, 2023 at 06:16:47PM -0700, Andrew Pinski wrote:
> This is a simple error recovery issue when c_safe_arg_type_equiv_p
> was added in r8-5312-gc65e18d3331aa999. The issue is that after
> an error, an argument type (of a function type) might turn
> into an error mark node and c_safe_arg_type_equiv_p was not ready
> for that. So this just adds a check for error operand for its
> arguments before getting the main variant.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Please don't include this line in the commit message.
> PR c/101285
>
> gcc/c/ChangeLog:
>
> * c-typeck.cc (c_safe_arg_type_equiv_p): Return true for error
> operands early.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/pr101285-1.c: New test.
> ---
> gcc/c/c-typeck.cc | 3 +++
> gcc/testsuite/gcc.dg/pr101285-1.c | 10 ++++++++++
> 2 files changed, 13 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/pr101285-1.c
>
> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
> index e55e887da14..6e044b4afbc 100644
> --- a/gcc/c/c-typeck.cc
> +++ b/gcc/c/c-typeck.cc
> @@ -5960,6 +5960,9 @@ handle_warn_cast_qual (location_t loc, tree type, tree
> otype)
> static bool
> c_safe_arg_type_equiv_p (tree t1, tree t2)
> {
> + if (error_operand_p (t1) || error_operand_p (t2))
> + return true;
I thought it would be more natural to return false but that would result in:
cast between incompatible function types from 'void (*)(int *)' to 'void
(*)(<type-error>)'
but we don't want that so pretending the cast is safe is probably better.
> t1 = TYPE_MAIN_VARIANT (t1);
> t2 = TYPE_MAIN_VARIANT (t2);
>
> diff --git a/gcc/testsuite/gcc.dg/pr101285-1.c
> b/gcc/testsuite/gcc.dg/pr101285-1.c
> new file mode 100644
> index 00000000000..831e35f7662
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr101285-1.c
> @@ -0,0 +1,10 @@
Let's put
/* PR c/101285 */
here.
> +/* { dg-do compile } */
> +/* { dg-options "-W -Wall" } */
> +const int b;
> +typedef void (*ft1)(int[b++]); /* { dg-error "read-only variable" } */
> +void bar(int * z);
> +void baz()
> +{
> + (ft1) bar; /* { dg-warning "statement with no effect" } */
> +}
> +
Extra newline.
Thanks,
Marek
