In mem1.c 1.50 and mem2.c 1.13 from 2021-08-28, I accidentally changed
the initialization of mblklen from round_up to round_down, trying to
avoid a division instruction.
On NetBSD x86_64 this resulted in a few more malloc calls, but on Cygwin
with its 64k pagesize, mblklen became 0. Later, the function xalloc in
lint2 called xalloc(mblklen) and blindly assumed that the returned
memory would be large enough. This in turn led to out-of-bounds memory
access and crashes. Lint1 was not affected since it adjust mblklen
during runtime if it gets too small.
This fixes the warning from lint2 that these functions return values
which are sometimes ignored.
The remaining calls to fprintf that ignore the return value come from
scan.c. Lint does not currently detect the auto-generated portions of
that file and the interesting ones since it assumes that scan.c is the
main filename, see expr_zalloc_tnode.
No functional change.
It's strange that GCC does not warn about the nonliteral format strings
in lint1/err.c, lint2/msg.c and lint2/read.c, despite -Wformat=2, but
Clang does.
_NETBSD_SOURCE as this makes cross building from older/newer versions of
NetBSD harder, not easier (and also makes the resulting tools 'different')
Wrap all required code with the inclusion of nbtool_config.h, attempt to
only use POSIX code in all places (or when reasonable test w. configure and
provide definitions: ala u_int, etc).
Reviewed by lukem. Tested on FreeBSD 4.9, Redhat Linux ES3, NetBSD 1.6.2 x86
NetBSD current (x86 and amd64) and Solaris 9.
Fixes PR's: PR#17762 PR#25944
rillig