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!

-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

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