[gcc r16-9716] libstdc++: Replace invalid memset usage in testsuite

[Jonathan Wakely]

https://gcc.gnu.org/g:37b61808f7e6ce007b1070154864c177f02cd1d4

commit r16-9716-g37b61808f7e6ce007b1070154864c177f02cd1d4
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Sep 29 15:12:51 2026 +0100

    libstdc++: Replace invalid memset usage in testsuite
    
    The __gnu_test::MallocInfo struct has a non-trivial default constructor
    which causes -Wclass-memaccess warnings when it is cleared using memset.
    Use assignment from value-initialized objects instead of memset.
    
    For consistency, clear rusage structs the same way.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/util/testsuite_performance.h (resource_counter): Do
            not use memset to clear non-trivial objects.
    
    Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
    (cherry picked from commit 166f136e186619e84ab64427bf106383982a96ab)

Diff:
---
 libstdc++-v3/testsuite/util/testsuite_performance.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/libstdc++-v3/testsuite/util/testsuite_performance.h b/libstdc++-v3/testsuite/util/testsuite_performance.h
index 524a1a577858..ff85d77eb45d 100644
--- a/libstdc++-v3/testsuite/util/testsuite_performance.h
+++ b/libstdc++-v3/testsuite/util/testsuite_performance.h
@@ -157,17 +157,17 @@ namespace __gnu_test
     void
     clear() throw()
     {
-      memset(&rusage_begin, 0, sizeof(rusage_begin));
-      memset(&rusage_end, 0, sizeof(rusage_end));
-      memset(&allocation_begin, 0, sizeof(allocation_begin));
-      memset(&allocation_end, 0, sizeof(allocation_end));
+      rusage_begin = rusage();
+      rusage_end = rusage();
+      allocation_begin = MallocInfo();
+      allocation_end = MallocInfo();
     }
 
     void
     start()
     {
       if (getrusage(who, &rusage_begin) != 0 )
-	memset(&rusage_begin, 0, sizeof(rusage_begin));
+	rusage_begin = rusage();
       void* p __attribute__((unused)) = malloc(0); // Needed for some implementations.
       allocation_begin = malloc_info();
     }
@@ -176,7 +176,7 @@ namespace __gnu_test
     stop()
     {
       if (getrusage(who, &rusage_end) != 0 )
-	memset(&rusage_end, 0, sizeof(rusage_end));
+	rusage_end = rusage();
       allocation_end = malloc_info();
     }