mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-01-27 03:13:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

libstdc++: Fix _Hash_bytes for I16LP32 targets [PR107885]

Browse Source 
For H8/300 size_t is 32 bits wide, but (unsigned char)buf[2] << 16
promotes to int which is only 16 bits wide. The shift is then undefined.
This fixes it by converting to size_t before shifting.

libstdc++-v3/ChangeLog:

	PR libstdc++/107885
	* libsupc++/hash_bytes.cc (_Hash_bytes): Convert to size_t
	instead of implicit integer promotion to 16 bits.
This commit is contained in:
Jonathan Wakely 2022-11-28 10:52:23 +00:00
parent f7a41b5cfd
commit 7b79fa9309
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
libstdc++-v3/libsupc++/hash_bytes.cc
View File

@ -90,17 +90,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
len -= 4;
}
size_t k;
// Handle the last few bytes of the input array.
switch(len)
{
case 3:
hash ^= static_cast<unsigned char>(buf[2]) << 16;
k = static_cast<unsigned char>(buf[2]);
hash ^= k << 16;
[[gnu::fallthrough]];
case 2:
hash ^= static_cast<unsigned char>(buf[1]) << 8;
k = static_cast<unsigned char>(buf[1]);
hash ^= k << 8;
[[gnu::fallthrough]];
case 1:
hash ^= static_cast<unsigned char>(buf[0]);
k = static_cast<unsigned char>(buf[0]);
hash ^= k;
hash *= m;
};