https://bugs.gentoo.org/661328

--- clamav-0.101.2/m4/reorganization/libs/xml.m4
+++ clamav-0.101.2/m4/reorganization/libs/xml.m4
@@ -4,55 +4,19 @@
 [AS_HELP_STRING([--disable-xml], [do not include DMG and XAR support])],
 want_xml=$enableval, want_xml="auto")
 
-XML_HOME=""
-if test "X$want_xml" != "Xno"; then
-  AC_MSG_CHECKING([for libxml2 installation])
-  AC_ARG_WITH([xml],
-    AS_HELP_STRING([--with-xml@<:@=DIR@:>@], [path to directory containing libxml2 library
-                    @<:@default=/usr/local or /usr if not found in /usr/local@:>@]),
-    [with_xml_val=$withval]
-  )
-fi
-
-AS_IF([test "x$with_xml_val" = "xno"], [XML_HOME=""],
-  [test "x$with_xml_val" = "xyes"], [XML_HOME="/usr/local"],
-  [XML_HOME="$with_xml_val"])
-
-AS_IF([test "x$XML_HOME" != "x"], [
-   AS_IF([test ! -x "$XML_HOME/bin/xml2-config"], [XML_HOME=""])
-   ])
-
-AS_IF([test "x$XML_HOME" = "x" -a "x$with_xml_val" = "xyes"], [
-   AS_IF([test -x "/usr/bin/xml2-config"], [XML_HOME="/usr"])
-   ])
-
-if test "x$XML_HOME" != "x"; then
-  AC_MSG_RESULT([$XML_HOME])
-else
-  AC_MSG_RESULT([not found])
-fi
-
-found_xml="no"
-XMLCONF_VERSION=""
-XML_CPPFLAGS=""
-XML_LIBS=""
-if test "x$XML_HOME" != "x"; then
-  AC_MSG_CHECKING([xml2-config version])
-  XMLCONF_VERSION="`$XML_HOME/bin/xml2-config --version`"
-  if test "x%XMLCONF_VERSION" != "x"; then
-    AC_MSG_RESULT([$XMLCONF_VERSION])
-    found_xml="yes"
-    XML_CPPFLAGS="`$XML_HOME/bin/xml2-config --cflags`"
-    XML_LIBS="`$XML_HOME/bin/xml2-config --libs`"
-    AS_ECHO("$XML_CPPFLAGS")
-    AS_ECHO("$XML_LIBS")
-  else
-    AC_MSG_ERROR([xml2-config failed])
-  fi
-fi
+PKG_CHECK_MODULES([XML], [libxml-2.0],
+	[found_xml=yes],
+	[
+		found_xml=no
+		AS_IF([test "x$want_xml" = xyes],
+			[AC_MSG_ERROR([--enable-xml set but cannot find libxml2])]
+		)
+	]
+)
 
 working_xml="no"
 if test "X$found_xml" != "Xno"; then
+  XML_HOME=$(${PKG_CONFIG} --variable prefix libxml-2.0)
   AC_MSG_CHECKING([for xmlreader.h in $XML_HOME])
 
   if test ! -f "$XML_HOME/include/libxml2/libxml/xmlreader.h"; then
@@ -61,6 +25,7 @@
     AC_MSG_RESULT([found])
     save_LIBS="$LIBS"
     save_CPPFLAGS="$CPPFLAGS"
+    XML_CPPFLAGS="$XML_CFLAGS"
     CPPFLAGS="$CPPFLAGS $XML_CPPFLAGS"
     save_LDFLAGS="$LDFLAGS"
     LDFLAGS="$LDFLAGS $XML_LIBS"