[test-suite] Use cmake `find_package` to search zLib for ClamAV test case

[atanasyan]

Summary

• in case of cross-compilation using find_package allows to provide path to target specific libraries using single CMAKE_PREFIX_PATH variable.

• zLib is manadatory for ClamAV test case so if it does not exist it is better to get know about that early

• if zLib cannot be found as a standard package we still can use it providing paths to headers and libraries explicitly by CMAKE_xxx_FLAGS variables

[MatzeB]

We really should avoid external dependencies in benchmarks in the long term. But this is indeed the right way to deal with that benchmark today. Some comments:

• cmake also offers https://cmake.org/cmake/help/v3.0/module/FindZLIB.html how does that compare to find_package(ZLIB)?
• I'd just disable the whole benchmark if libz couldn't be found instead of trying anyway.

In any way this is simple enough to just commit (there's always post-commit review).

[atanasyan]

In D17196#351593, @MatzeB wrote:

• cmake also offers https://cmake.org/cmake/help/v3.0/module/FindZLIB.html how does that compare to find_package(ZLIB)?

find_package(ZLIB) uses FindZLIB module to find zLib. In general, as far as I understand if you have FindSOMETHING module you need to use find_package(SOMETHING) to search the corresponding package.

• I'd just disable the whole benchmark if libz couldn't be found instead of trying anyway.

I am afraid a bit that somebody just copy target specific libz.so and zlib.h to say the single directory. In that case find_package does not find the library. But if we disable the whole benchmark the cmake code becomes shorter. So I modify the script this way and commit. If somebody stumble to this problem we will know how to fix it.

In any way this is simple enough to just commit (there's always post-commit review).

Thanks for review.

test-suite/trunk/MultiSource/Applications/ClamAV/CMakeLists.txt

 set(TMP1  aspack.c autoit.c binhex.c blob.c cab.c chmunpack.c cvd.c dconf.c dsig.c elf.c entconv.c filetypes.c fsg.c hashtab.c htmlnorm.c is_tar.c jscript.c line.c lockdb.c matcher-ac.c matcher-bm.c matcher.c mbox.c md5.c message.c mew.c msexpand.c mspack.c ole2_extract.c others.c packlibs.c pdf.c pe.c petite.c phishcheck.c phish_domaincheck_db.c phish_whitelist.c pst.c readdb.c rebuildpe.c regex_list.c rtf.c scanners.c sis.c snprintf.c special.c spin.c str.c suecrypt.c table.c text.c tnef.c unarj.c unsp.c untar.c unzip.c upack.c upx.c uuencode.c vba_extract.c wwunpack.c yc.c)
 llvm_prepend(TMP1 libclamav_ ${TMP1})
 set(TMP2  clamscan.c manager.c others.c treewalk.c)
 llvm_prepend(TMP2 clamscan_ ${TMP2})
 set(TMP3  cdiff.c cfgparser.c getopt.c misc.c network.c options.c output.c sha256.c)
 llvm_prepend(TMP3 shared_ ${TMP3})
 set(TMP4  regerror.c regfree.c regcomp.c  regexec.c strlcpy.c)
 llvm_prepend(TMP4 libclamav_regex_ ${TMP4})
 set(TMP5  nulsft.c bzlib.c infblock.c LZMADecode.c )
 llvm_prepend(TMP5 libclamav_nsis_ ${TMP5})
 set(Source ${TMP1} ${TMP2} ${TMP3} ${TMP4} ${TMP5})
 set(INPUT ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam.cab ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clamdoc.tar.gz ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam.exe ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam.exe.bz2 ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam-v2.rar ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam-v3.rar ${CMAKE_CURRENT_SOURCE_DIR}/inputs/clam.zip ${CMAKE_CURRENT_SOURCE_DIR}/inputs/README ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/Doc11.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/Doc1.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/Doc22.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/Doc2.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/doc3.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/docCLAMexe.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/rtf1.rtf ${CMAKE_CURRENT_SOURCE_DIR}/inputs/rtf-test/rtf-novirus.rtf)
 set(PROG clamscan)
 list(APPEND CPPFLAGS -DHAVE_CONFIG_H -I. -DDONT_LOCK_DBDIRS)
-set(LDFLAGS -lz)
+
+# Find zLib library required for building ClamAV
+find_package(ZLIB REQUIRED)
+include_directories(${ZLIB_INCLUDE_DIRS})
+set(LDFLAGS ${ZLIB_LIBRARIES})
+
 set(RUN_OPTIONS --debug --exclude-dir .svn --verbose -d${CMAKE_CURRENT_SOURCE_DIR}/dbdir -r ${INPUT})
 if("${TARGET_OS}" STREQUAL "Darwin")
   list(APPEND CPPFLAGS -DC_DARWIN)
 endif()
 if("${TARGET_OS}" STREQUAL "AIX")
   list(APPEND CPPFLAGS -DC_AIX)
 endif()
 if("${TARGET_OS}" STREQUAL "IRIX")