tree b715114847be079fc5133ff821f28bc8b6c8a193
parent 5c58e092f3df0e70235a4cdd41790a505e1ee596
author Nick Kralevich <nnk@google.com> 1554412783 -0700
committer Nick Kralevich <nnk@google.com> 1554414791 -0700

zip_archive.cc: fix ubsan false positive

std::hash returns a 64 bit value, which is truncated to a 32 bit value
in ComputeHash. ubsan's implicit-unsigned-integer-truncation doesn't
like this implicit truncation and crashes the program. Explicitly strip
off the top order bits after computing the hash.

Remove the windows specific version of the hash computation. The windows
compile now uses clang, so this code is obsolete. This also avoids us
having to add __attribute__((no_sanitize("integer"))) to the windows
code.

This is needed to support Android booting with ubsan's
implicit-unsigned-integer-truncation option enabled.

Test: compiles and boots
Bug: 122975762
Change-Id: I2f05fbf5ffee8e90a66a6fda32e80de9cca246c0