Add -Wsign-compare to the project's CFLAGS #118
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The lttng-tools code base has many erroneous comparisons between
signed and unsigned values.
While some uses are benign, like using a signed integer to loop
between
0
andsizeof(struct some_structure)
, there are manycases where the "signed integer" result of a syscall
(e.g.
sendmsg
,recvmsg
,read
,write
) is compared to an expectedstructure size using the
sizeof
operator, which returns a result of typesize_t
.The following pattern:
is common and unsafe if the intention is to check for an error
(
-1
) and that the operation was completed (ret == sizeof(...)
).Follow-up patches address the various instances of the problem.
The
Clean-up:
prefix is used when the comparison was safeand the change is mainly done to silence the warning.
The
Fix:
prefix is used when the commit fixes an unsafecomparison and should be backported to previous versions.