On Mon, Jan 27, 2025 at 1:28 PM Lewis Hyatt <lhy...@gmail.com> wrote:
>
> Hello-
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115913#c10
>
> This tweak to optc-save-gen.awk weakens the check performed by
> cl_optimization_compare() to avoid checking asserts that have been there
> since this function was first added in r11-1141. Is it OK for 15 please? I
> think it would be appropriate to backport back to 12,13,14 as well.
> Bootstrap + regtest all languages on x86-64 Linux with no issues. Thanks!
The check is supposed to verify that cl_target_option_restore does not
alter the set of global options restored by cl_optimization_restore (or others).
Since there are no warning flags restored in cl_optimization_restore the
patch is OK.
I suppose to follow the intend we'd have to save the current set of diagnostic
options after cl_optimization_restore and compare those as well after
the cl_target_option_restore.
Thanks,
Richard.
> -Lewis
>
> -- >8 --
>
> At the end of a sequence like:
> #pragma GCC push_options
> ...
> #pragma GCC pop_options
>
> the handler for pop_options calls cl_optimization_compare() (as generated by
> optc-save-gen.awk) to make sure that all global state has been restored to
> the value it had prior to the push_options call. The verification is
> performed for almost all entries in the global_options struct. This leads to
> unexpected checking asserts, as discussed in the PR, in case the state of
> warnings-related options has been intentionally modified in between
> push_options and pop_options via a call to #pragma GCC diagnostic. Address
> that by skipping the verification for CL_WARNING-flagged options.
>
> gcc/ChangeLog:
>
> PR middle-end/115913
> * optc-save-gen.awk (cl_optimization_compare): Skip options with
> CL_WARNING flag.
>
> gcc/testsuite/ChangeLog:
>
> PR middle-end/115913
> * c-c++-common/cpp/pr115913.c: New test.
> ---
> gcc/optc-save-gen.awk | 5 +++++
> gcc/testsuite/c-c++-common/cpp/pr115913.c | 7 +++++++
> 2 files changed, 12 insertions(+)
> create mode 100644 gcc/testsuite/c-c++-common/cpp/pr115913.c
>
> diff --git a/gcc/optc-save-gen.awk b/gcc/optc-save-gen.awk
> index fa9218472ed..a3d7e5a478e 100644
> --- a/gcc/optc-save-gen.awk
> +++ b/gcc/optc-save-gen.awk
> @@ -1484,6 +1484,11 @@ for (i = 0; i < n_opts; i++) {
> if (name == "")
> continue;
>
> + # We do not want to compare warning-related options, since they
> + # might have been modified by a #pragma GCC diagnostic.
> + if (flag_set_p("Warning", flags[i]))
> + continue;
> +
> if (name in checked_options)
> continue;
> checked_options[name]++
> diff --git a/gcc/testsuite/c-c++-common/cpp/pr115913.c
> b/gcc/testsuite/c-c++-common/cpp/pr115913.c
> new file mode 100644
> index 00000000000..b9d10cda8d2
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/cpp/pr115913.c
> @@ -0,0 +1,7 @@
> +/* { dg-do preprocess } */
> +/* PR middle-end/115913 */
> +#pragma GCC push_options
> +#pragma GCC diagnostic warning "-Wundef"
> +/* The call to cl_optimization_compare performed by pop_options should not
> + lead to a checking failure. */
> +#pragma GCC pop_options
