libarchive: Clean up configuration within CMake build

Require ZLIB but skip LZMA and XML support.  Mark ZLIB and ICONV cache
variables advanced.

Utilities/cmlibarchive/CMakeLists.txt

@@ -164,9 +164,9 @@ IF(ZLIB_FOUND)
       "#ifndef ZLIB_WINAPI\n#define ZLIB_WINAPI\n#endif\n#include <zlib.h>\nint main() {uLong f = zlibCompileFlags(); return (f&(1U<<10))?0:-1; }"
       ZLIB_WINAPI)
   ENDIF(WIN32 AND NOT CYGWIN)
+ELSE(ZLIB_FOUND)
+  MESSAGE(FATAL_ERROR "CMake requires zlib to be available to libarchive")
 ENDIF(ZLIB_FOUND)
-MARK_AS_ADVANCED(CLEAR ZLIB_INCLUDE_DIR)
-MARK_AS_ADVANCED(CLEAR ZLIB_LIBRARY)
 #
 # Find BZip2
 #
@@ -179,6 +179,8 @@ IF(BZIP2_FOUND)
 ENDIF(BZIP2_FOUND)
 MARK_AS_ADVANCED(CLEAR BZIP2_INCLUDE_DIR)
 MARK_AS_ADVANCED(CLEAR BZIP2_LIBRARY)
+
+IF(0) # CMake does not need LZMA support in libarchive
 #
 # Find LZMA
 #
@@ -194,6 +196,7 @@ ELSEIF(LZMADEC_FOUND)
   INCLUDE_DIRECTORIES(${LZMADEC_INCLUDE_DIR})
   LIST(APPEND ADDITIONAL_LIBS ${LZMADEC_LIBRARIES})
 ENDIF(LZMA_FOUND)
+ENDIF()
 
 #
 # Check headers
@@ -517,6 +520,7 @@ ENDMACRO(CHECK_ICONV TRY_ICONV_CONST)
 
 IF(ENABLE_ICONV)
   FIND_PATH(ICONV_INCLUDE_DIR iconv.h)
+  MARK_AS_ADVANCED(ICONV_INCLUDE_DIR)
   IF(ICONV_INCLUDE_DIR)
     #SET(INCLUDES ${INCLUDES} "iconv.h")
     SET(HAVE_ICONV_H 1)
@@ -566,6 +570,7 @@ ELSE(ENABLE_ICONV)
   UNSET(LIBICONV_PATH CACHE)
 ENDIF(ENABLE_ICONV)
 
+IF(0) # CMake does not need XML support in libarchive
 #
 # Find Libxml2
 #
@@ -591,6 +596,7 @@ ELSE(LIBXML2_FOUND)
     LA_CHECK_INCLUDE_FILE("expat.h" HAVE_EXPAT_H)
   ENDIF(EXPAT_FOUND)
 ENDIF(LIBXML2_FOUND)
+ENDIF()
 
 #
 # Check functions