[gcc r10-6915] libstdc++: Fix failing test in debug mode

[Jonathan Wakely]

https://gcc.gnu.org/g:86e2dc22c91a722d2624c0010d81f1ce4b911bbd

commit r10-6915-g86e2dc22c91a722d2624c0010d81f1ce4b911bbd
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Feb 27 17:22:50 2020 +0000

    libstdc++: Fix failing test in debug mode
    
    This fixes a failure due to a (correct) warning seen when testing with
    -D_GLIBCXX_USE_CXX11_ABI=0 -D_GLIBCXX_ASSERTIONS:
    
    include/bits/char_traits.h:365: warning: 'void* __builtin_memcpy(void*, const void*, long unsigned int)'
    specified bound 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
    
    FAIL: 21_strings/basic_string/cons/char/1.cc (test for excess errors)
    
    	* testsuite/21_strings/basic_string/cons/char/1.cc: Disable
    	-Wstringop-overflow warnings.

Diff:
---
 libstdc++-v3/ChangeLog                                        | 5 +++++
 libstdc++-v3/testsuite/21_strings/basic_string/cons/char/1.cc | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 26e288d..24ce2a1 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2020-02-28  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/21_strings/basic_string/cons/char/1.cc: Disable
+	-Wstringop-overflow warnings.
+
 2020-02-27  Jonathan Wakely  <jwakely@redhat.com>
 
 	* testsuite/lib/libstdc++.exp (v3_target_compile): Add
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/1.cc b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/1.cc
index 6605458..1c3e43f 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/1.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/cons/char/1.cc
@@ -19,6 +19,8 @@
 
 // 21.3.1 basic_string constructors.
 
+// { dg-options "-Wno-stringop-overflow" }
+
 #include <new>
 #include <stdexcept>
 #include <testsuite_hooks.h>