Comment 4 for bug 1641612
Revision history for this message
| Laurynas Biveinis (laurynas-biveinis) wrote Re: New compilation warnings with GCC 6 (-Wshift-negative-value, -Wdeprecated-declarations, -Wnonnull-compare) | #4 |
For InnoDB -Wnonnull-compare, backport
commit 7b899ac00c5d6a1
Author: Marko Makela <email address hidden>
Date: Wed Oct 8 10:31:13 2014 +0300
Bug#19632776 Code gets incorrectly optimized away by gcc
As reported in https:/
it is possible that gcc incorrectly optimizes away some code
when a function that takes a pointer or reference as a parameter
is declared as attribute((const)) or attribute((pure)).
The function affected was page_zip_
As a preventive measure, we will remove the potentially problematic
attributes from all functions that take pointers or references that
they are dereferencing. Functions that perform pointer arithmetics
without dereferencing the pointers should be safe: page_offset() is
an example.
While we are at it, remove also some attribute(
This attribute is dangerous, because it does not always generate
a warning when NULL may be passed, but it may optimize away code
for handling the NULL case. We wanted this attribute for the sake
of the warnings, not for the optimizations.
rb#6940 approved by Vasil Dimov and Jimmy Yang