tree 3253a41ec24827c1c556b22c4591550b72919b2b
parent 6c08ac72c6ce9faf66bf28ee75cbb87413daa6aa
author Jim Apple <jbapple-impala@apache.org> 1489867010 -0700
committer James E. King, III <jking@apache.org> 1490444178 -0400

THRIFT-2026: Eliminate some undefined behavior in C/C++
Clients: glib, C++
Patch: Jim Apple <jbapple-impala@apache.org>

This closes #1214

This patch fixes some undefined behavior were found using Clang's
UndefinedBehaviorSanitizer (UBSan). To check for undefined behavior,
run /build/docker/scripts/ubsan.sh. This is run during CI builds, as
well.

The examples of the types of undefined behavior fixed in this commit
are:

1. Enumerations exhibit undefined behavior when they have values
   outside of a range dependent on the values of their enumerators, as
   specified in C++14's chapter 7.2 ("Enumeration declarations"),
   paragraph 8.

2. Left shift of negative values, used in zigzag encoding, is
   undefined behavior. See 5.8 ("Shift operators"), paragraph 2 for
   C++ and 6.5.7 ("Bitwise shift operators"), paragraph 4 for C99 and
   C11.