[Bug other/116143] New: [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[Bug other/116143] New: [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

            Bug ID: 116143
           Summary: [15 regression] gcc.dg/plugin/diagnostic-* test fails
                    intermittently
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at gcc dot gnu.org
  Target Milestone: ---

There are a bunch of gcc.dg/plugin/diagnostic-* tests that started failing
intermittently a bit ago on one of our powerpc64 BE machines.

FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
15-111
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
15-111
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-1.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 18)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 18)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
20-121
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
20-121
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-2.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 18)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 18)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
20-121
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
20-121
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-inline-events-3.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-none.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-none.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-none.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-none.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 12)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 12)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 35)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 35)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 36)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 36)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-plain.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 36)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 36)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 37)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 37)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 34 (test for errors, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 34 (test for errors, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 35 (test for warnings, line
25)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 35 (test for warnings, line
25)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 36 (test for warnings, line
27)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 36 (test for warnings, line
27)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 37 (test for warnings, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 37 (test for warnings, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-1.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 34 (test for errors, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 34 (test for errors, line
29)
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
36-52
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
36-52
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-2.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-3.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
36-74
FAIL: gcc.dg/plugin/diagnostic-test-paths-3.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
36-74
FAIL: gcc.dg/plugin/diagnostic-test-paths-3.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-3.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
33-83
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
33-83
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-4.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "codeFlows": \\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "codeFlows": \\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "extensions": \\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "extensions": \\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "name":
"diagnostic_plugin_test_paths"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "name":
"diagnostic_plugin_test_paths"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "passing
NULL as argument 1 to 'PyList_Append' which requires a non-NULL parameter"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "passing
NULL as argument 1 to 'PyList_Append' which requires a non-NULL parameter"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when
'PyList_New' fails, returning NULL"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when
'PyList_New' fails, returning NULL"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when 'i <
count'"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when 'i <
count'"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when
calling 'PyList_Append', passing NULL from \\\\(1\\\\) as argument 1"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "when
calling 'PyList_Append', passing NULL from \\\\(1\\\\) as argument 1"
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "threadFlows":
\\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-5.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "threadFlows":
\\\\[
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 17)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 17)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
21-71
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so  expected multiline pattern lines
21-71
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 1
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 1
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 2
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 2
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 3
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 3
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 4
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 4
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 5
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 5
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 6
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "executionOrder": 6
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "id": "Thread 1"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "id": "Thread 1"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "id": "Thread 2"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "id": "Thread 2"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "deadlock
due to inconsistent lock acquisition order"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so  scan-sarif-file "text": "deadlock
due to inconsistent lock acquisition order"
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 10)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 10)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 14)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 14)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 15)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 15)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 16)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 16)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 8)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 8)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 9)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 9)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 17 (test for warnings, line
16)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  at line 17 (test for warnings, line
16)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
FAIL: gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)

When they fail they all fail like this:

Executing on host: /home/gccbuild/build/nightly/build-gcc-trunk/gcc/xgcc
-B/home/gccbuild/build/nightly/build-gcc-trunk/gcc/ 
/home/gccbuild/gcc_trunk_git/gcc/gcc/testsuite/gcc.dg/plugin/diagnostic-path-format-separate-events.c
 -m32   -fdiagnostics-plain-output  -fplugin=./diagnostic_plugin_test_paths.so
-fdiagnostics-path-format=separate-events -S -o
diagnostic-path-format-separate-events.s    (timeout = 300)
spawn -ignore SIGHUP /home/gccbuild/build/nightly/build-gcc-trunk/gcc/xgcc
-B/home/gccbuild/build/nightly/build-gcc-trunk/gcc/
/home/gccbuild/gcc_trunk_git/gcc/gcc/testsuite/gcc.dg/plugin/diagnostic-path-format-separate-events.c
-m32 -fdiagnostics-plain-output -fplugin=./diagnostic_plugin_test_paths.so
-fdiagnostics-path-format=separate-events -S -o
diagnostic-path-format-separate-events.s
cc1: error: cannot load plugin ./diagnostic_plugin_test_paths.so:
./diagnostic_plugin_test_paths.so: undefined symbol:
_ZNK22simple_diagnostic_path10num_eventsEv
compiler exited with status 1
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 13)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 36)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so  (test for warnings, line 37)
FAIL: gcc.dg/plugin/diagnostic-path-format-separate-events.c
-fplugin=./diagnostic_plugin_test_paths.so (test for excess errors)
Excess errors:
cc1: error: cannot load plugin ./diagnostic_plugin_test_paths.so:
./diagnostic_plugin_test_paths.so: undefined symbol:
_ZNK22simple_diagnostic_path10num_eventsEv

The first time I saw the failure was with 

17d0982f425dbdeb528b70d141e70b006f6b9df6, r15-1423-g17d0982f425dbd

But that is not the source.  Just before that were several changes to the
diagnostician code by David Malcolm.

524cdf4dab610e6e53b3b033eacbdb1a03687cc7
c371d7bdbe69201b4c91179ff6f3e2237e0e7fbe
bdcfe7f7f50ec64b45581a175d1eca41c74a3dfe

and more which may be the source.

As this is intermittent I have not been able to trace it exactly to a specific
change.

[Bug other/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Sorry about this.

Demangling,
  _ZNK22simple_diagnostic_path10num_eventsEv
is
  simple_diagnostic_path::num_events() const

which is a vfunc implemented in gcc/simple-diagnostic-path.o

My guess is that nothing is using class simple_diagnostic_path in cc1, and thus
the code for simple_diagnostic_path is being dropped by the linker, so it's not
available to the plugin.

[Bug other/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

Segher Boessenkool <segher at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-07-30

--- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Yup, that sounds eminently plausible :-)  Thanks.

How will you fix this?  Add an  attribute ((used))  ?

[Bug other/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

--- Comment #3 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #2)
> Yup, that sounds eminently plausible :-)  Thanks.

For the given that error message, yes, it seems plausible.  But I don't know
how an error like that can be intermittent.  I would expect if we pass the same
objects to the linker, the result should 100% be the same every time.

[Bug testsuite/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |15.0
          Component|other                       |testsuite
           Keywords|                            |testsuite-fail

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Also with plugins all symbols are exported so I don't see how they could be
dropped?

[Bug testsuite/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

--- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
(In reply to David Malcolm from comment #1)
[...snip...]
> My guess is that nothing is using class simple_diagnostic_path in cc1, and
> thus the code for simple_diagnostic_path is being dropped by the linker, so
> it's not available to the plugin.

It's used by a selftest in simple-diagnostic-path.cc, but that's only enabled
if
  #if CHECKING_P
so maybe this is failing on release builds and passing on debug builds???

FWIW I've seen a couple of patches in progress that add "real" uses of the
class to the middle-end (e.g. Qing's "[RFC][PATCH v1] Provide more contexts for
-Warray-bounds warning messages "
https://gcc.gnu.org/pipermail/gcc-patches/2024-July/656199.html )

[Bug testsuite/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

--- Comment #6 from Segher Boessenkool <segher at gcc dot gnu.org> ---
But even then, we should have something like attribute ((used)) to force it to
always be considered used -- this is exactly what that attribute is for!

It only doesn't have to be there if some symbol obviously is always used, but
that even means it is not inlined and optimised away, so this isn't often so
obvious even!

[Bug testsuite/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

--- Comment #7 from seurer at gcc dot gnu.org ---
I was wrong initially about this being intermittent.  It always fails for a
compiler built with --enable-checking=release and it started with
r15-1410-gf89f9c7ae7190c

[Bug testsuite/116143] [15 regression] gcc.dg/plugin/diagnostic-* test fails intermittently

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116143

John David Anglin <danglin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|powerpc64-linux-gnu         |powerpc64-linux-gnu
                   |                            |hppa-linux-gnu
                 CC|                            |danglin at gcc dot gnu.org
               Host|powerpc64-linux-gnu         |powerpc64-linux-gnu
                   |                            |hppa-linux-gnu
              Build|powerpc64-linux-gnu         |powerpc64-linux-gnu
                   |                            |hppa-linux-gnu

--- Comment #8 from John David Anglin <danglin at gcc dot gnu.org> ---
Same fails on hppa-linux-gnu:

cc1: error: cannot load plugin ./diagnostic_plugin_test_paths.so:
./diagnostic_p
lugin_test_paths.so: undefined symbol:
_ZNK22simple_diagnostic_path10num_eventsE
v