From: Jason Merrill <jason@redhat.com>
Date: Fri, 19 Aug 2022 03:53:16 +0000 (-0400)
Subject: libstdc++: avoid bogus -Wrestrict [PR105651]
X-Git-Tag: vendors/ARM/release-12.3.rel1~14
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=636795a6dfc17ead7b22b9f76b0fc47bdb9d357d;p=thirdparty%2Fgcc.git

libstdc++: avoid bogus -Wrestrict [PR105651]

	PR tree-optimization/105651

libstdc++-v3/ChangeLog:

	* include/bits/basic_string.tcc (_M_replace): Add an assert
	to avoid -Wrestrict false positive.
---

diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc
index 0696b96604c1..48fa28e64668 100644
--- a/libstdc++-v3/include/bits/basic_string.tcc
+++ b/libstdc++-v3/include/bits/basic_string.tcc
@@ -529,6 +529,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		    {
 		      const size_type __nleft = (__p + __len1) - __s;
 		      this->_S_move(__p, __s, __nleft);
+		      // Tell the middle-end that the copy can't overlap
+		      // (PR105651).
+		      if (__len2 < __nleft)
+			__builtin_unreachable();
 		      this->_S_copy(__p + __nleft, __p + __len2,
 				    __len2 - __nleft);
 		    }