From the devel mailing list.  Another user on AIX 6.1 having the same issue:

http://lists.clamav.net/pipermail/clamav-devel/2018-April/000397.html

-- 

It will be tough for us to fix this, because I don't have an AIX machine to test with.  

A quick Google search for "conflicting types for 'fsync_range64'" shows a bunch fo people with similar errors compiling other software on AIX.  The 2nd link down had a similar issue and appear to have to worked around it by rearranging their #include's:
https://github.com/nagios-plugins/nagios-plugins/issues/40 

Hard to say if we could do something similar.  Again, I don't have the means to test any changes. 

If you find a fix, we would be happy to try to include it.

Appreciate the response.
As a user of an IBM UNIX (AIX) system I have problems accessing many web
sites and the one you referenced is one of them.  (IBM refuses to release
an updated version of firefox!)

Not sure I would know how to fix the problem even if I could access the
pointed to web site.  It has been a very LONG time since I developed
software and/or debugged code. If the patch is obvious I am usually
able to apply it to the source code.  (The stuff in the make files
used to build the source tree is beyond my knowledge.  I can barely
figure out what is going on in a very simple makefile.)

I know just enough to get myself into trouble.
I do know how to compile the source tree; but it just
requires me to run configure and gmake.

I am really just an appreciative user of clamav.

I am more than willing to run test cases for you if that will
help.  All three of my servers are not open to the www; but I
can download files.

Editorial Note:
How far we have come.
So many things developed in the UNIX world no longer work
on pure UNIX systems.
I am surprised that anyone would purchase a pure UNIX system
these days because to maintain them one has to purchase a PC.
Thus if one has to purchase a PC to keep the UNIX system working
why not just move everything  to a PC workstation/tablet/server
system. That would make a whole lot more economic sense.

*** Bug 12106 has been marked as a duplicate of this bug. ***

I suppose it's worth mentioning that Tsutomu has had some luck setting the following environment variables prior to building.  He's presently having issues linking libmspack after that, however:


# export OBJECT_MODE="64"
# export CFLAGS="-maix64"               
# export LDFLAGS="-maix64 -Wl,-bbigtoc"
# ./configure
# make

Hi Micah Snyder,
  Thanks for the suggestion.
  I applied the following after unpacking the tar file.

CC=/opt/freeware/bin/gcc
CFLAGS="-D_ALL_SOURCE -maix64"
LDFLAGS="-lpthreads -maix64 -Wl,-bbigtoc"
export OBJECT_MODE="64"
export CC CFLAGS LDFLAGS
./configure

  gmake followed by gmake check produced the following results:

============================================================================
Testsuite summary for ClamAV 0.100.0
============================================================================
# TOTAL: 13
# PASS:  7
# SKIP:  6
# XFAIL: 0
# FAIL:  0
# XPASS: 0
# ERROR: 0
============================================================================

  I guess this means it works on my AIX 5.3 system.
  When I get a chance I will try building it on my AIX 7.1 system.
  Will let you know if that works!

Thanks for the help!

Ops!
Celebrated to quickly.
When I did gmake install I got the following:

libtool: install: ../config/install-sh -c .libs/libclamunrar.a /usr/local/lib/ppc64/libclamunrar.a
libtool: install: ../config/install-sh -c .libs/libclamunrar.lai /usr/local/lib/ppc64/libclamunrar.la
libtool: install: warning: relinking `libclamunrar_iface.la'
libtool: install: (cd /tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav; /bin/sh /tmp/InstallSW/AntiVirus/clamav-0.100.0/libtool  --silent --tag CC --mode=relink /tmp/InstallSW/AntiVirus/clamav-0.100.0/config/compile /opt/freeware/bin/gcc -D_ALL_SOURCE -maix64 -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -module -thread-safe -version-info 8:1:1 -no-undefined -lpthreads -maix64 -Wl,-bbigtoc -o libclamunrar_iface.la -rpath /usr/local/lib/ppc64 unrar_iface.lo libclamunrar.la )
ld: 0711-851 SEVERE ERROR: Output file: .libs/libclamunrar_iface.so.7
        The file is in use and cannot be overwritten.
collect2: error: ld returned 12 exit status
libtool: install: error: relink `libclamunrar_iface.la' with the above command before installing it
Makefile:1224: recipe for target 'install-libLTLIBRARIES' failed
gmake[4]: *** [install-libLTLIBRARIES] Error 1
gmake[4]: Leaving directory '/tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav'
Makefile:3649: recipe for target 'install-am' failed
gmake[3]: *** [install-am] Error 2
gmake[3]: Leaving directory '/tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav'
Makefile:3486: recipe for target 'install-recursive' failed
gmake[2]: *** [install-recursive] Error 1
gmake[2]: Leaving directory '/tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav'
Makefile:3643: recipe for target 'install' failed
gmake[1]: *** [install] Error 2
gmake[1]: Leaving directory '/tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav'
Makefile:756: recipe for target 'install-recursive' failed
gmake: *** [install-recursive] Error 1

Tried to build on AIX 7.1 and it failed.

gmake[4]: Entering directory '/tmp/InstallSW/AntiVirus/clamav-0.100.0/libclamav'

  CC       libclamav_internal_utils_la-strlcat.lo
  CCLD     libclamav_internal_utils.la
  CCLD     libclamav.la
ld: 0711-317 ERROR: Undefined symbol: .__cxa_finalize
ld: 0711-345 Use the -bloadmap or -bnoquiet option to obtain more information.
collect2: error: ld returned 8 exit status
Makefile:1273: recipe for target 'libclamav.la' failed

Tired to find a way to add the -bloadmap or -bonoquiet to
the Makefile; but I am just don't know how to read Makefile.
Tried to put gmake into debug mode to find the command
that was failing; but no luck.

Searched files in libclamav for the variable .__cxa_finalize
and could not find it anywhere.  Have no idea what is referencing it.

I give up!

Closing as there is a more recent ticket.

*** This bug has been marked as a duplicate of bug 12161 ***