Change the AM_PATH_XML2 macros to use pkg-config instead of xml2-config.

Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/d598d8af0913b6e3d4e61ffa62397a275b669dca]
Signed-off-by: Ross Burton <ross.burton@arm.com>

 libxml.m4 | 189 ++----------------------------------------------------
 1 file changed, 5 insertions(+), 184 deletions(-)

diff --git a/libxml.m4 b/libxml.m4
index fc7790c..1c53585 100644
--- a/libxml.m4
+++ b/libxml.m4
@@ -1,191 +1,12 @@
-# Configure paths for LIBXML2
-# Simon Josefsson 2020-02-12
-# Fix autoconf 2.70+ warnings
-# Mike Hommey 2004-06-19
-# use CPPFLAGS instead of CFLAGS
-# Toshio Kuratomi 2001-04-21
-# Adapted from:
-# Configure paths for GLIB
-# Owen Taylor     97-11-3
-
 dnl AM_PATH_XML2([MINIMUM-VERSION, [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
 dnl Test for XML, and define XML_CPPFLAGS and XML_LIBS
 dnl
-AC_DEFUN([AM_PATH_XML2],[ 
-AC_ARG_WITH(xml-prefix,
-            [  --with-xml-prefix=PFX   Prefix where libxml is installed (optional)],
-            xml_config_prefix="$withval", xml_config_prefix="")
-AC_ARG_WITH(xml-exec-prefix,
-            [  --with-xml-exec-prefix=PFX Exec prefix where libxml is installed (optional)],
-            xml_config_exec_prefix="$withval", xml_config_exec_prefix="")
-AC_ARG_ENABLE(xmltest,
-              [  --disable-xmltest       Do not try to compile and run a test LIBXML program],,
-              enable_xmltest=yes)
-
-  if test x$xml_config_exec_prefix != x ; then
-     xml_config_args="$xml_config_args"
-     if test x${XML2_CONFIG+set} != xset ; then
-        XML2_CONFIG=$xml_config_exec_prefix/bin/xml2-config
-     fi
-  fi
-  if test x$xml_config_prefix != x ; then
-     xml_config_args="$xml_config_args --prefix=$xml_config_prefix"
-     if test x${XML2_CONFIG+set} != xset ; then
-        XML2_CONFIG=$xml_config_prefix/bin/xml2-config
-     fi
-  fi
-
-  AC_PATH_PROG(XML2_CONFIG, xml2-config, no)
-  min_xml_version=ifelse([$1], ,2.0.0,[$1])
-  AC_MSG_CHECKING(for libxml - version >= $min_xml_version)
-  no_xml=""
-  if test "$XML2_CONFIG" = "no" ; then
-    no_xml=yes
-  else
-    XML_CPPFLAGS=`$XML2_CONFIG $xml_config_args --cflags`
-    XML_LIBS=`$XML2_CONFIG $xml_config_args --libs`
-    xml_config_major_version=`$XML2_CONFIG $xml_config_args --version | \
-           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\1/'`
-    xml_config_minor_version=`$XML2_CONFIG $xml_config_args --version | \
-           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\2/'`
-    xml_config_micro_version=`$XML2_CONFIG $xml_config_args --version | \
-           sed 's/\([[0-9]]*\).\([[0-9]]*\).\([[0-9]]*\)/\3/'`
-    if test "x$enable_xmltest" = "xyes" ; then
-      ac_save_CPPFLAGS="$CPPFLAGS"
-      ac_save_LIBS="$LIBS"
-      CPPFLAGS="$CPPFLAGS $XML_CPPFLAGS"
-      LIBS="$XML_LIBS $LIBS"
-dnl
-dnl Now check if the installed libxml is sufficiently new.
-dnl (Also sanity checks the results of xml2-config to some extent)
-dnl
-      rm -f conf.xmltest
-      AC_RUN_IFELSE(
-            [AC_LANG_SOURCE([[
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <libxml/xmlversion.h>
-
-int 
-main()
-{
-  int xml_major_version, xml_minor_version, xml_micro_version;
-  int major, minor, micro;
-  char *tmp_version;
-
-  system("touch conf.xmltest");
-
-  /* Capture xml2-config output via autoconf/configure variables */
-  /* HP/UX 9 (%@#!) writes to sscanf strings */
-  tmp_version = (char *)strdup("$min_xml_version");
-  if (sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) != 3) {
-     printf("%s, bad version string from xml2-config\n", "$min_xml_version");
-     exit(1);
-   }
-   free(tmp_version);
-
-   /* Capture the version information from the header files */
-   tmp_version = (char *)strdup(LIBXML_DOTTED_VERSION);
-   if (sscanf(tmp_version, "%d.%d.%d", &xml_major_version, &xml_minor_version, &xml_micro_version) != 3) {
-     printf("%s, bad version string from libxml includes\n", "LIBXML_DOTTED_VERSION");
-     exit(1);
-   }
-   free(tmp_version);
-
- /* Compare xml2-config output to the libxml headers */
-  if ((xml_major_version != $xml_config_major_version) ||
-      (xml_minor_version != $xml_config_minor_version) ||
-      (xml_micro_version != $xml_config_micro_version))
-    {
-      printf("*** libxml header files (version %d.%d.%d) do not match\n",
-         xml_major_version, xml_minor_version, xml_micro_version);
-      printf("*** xml2-config (version %d.%d.%d)\n",
-         $xml_config_major_version, $xml_config_minor_version, $xml_config_micro_version);
-      return 1;
-    } 
-/* Compare the headers to the library to make sure we match */
-  /* Less than ideal -- doesn't provide us with return value feedback, 
-   * only exits if there's a serious mismatch between header and library.
-   */
-    LIBXML_TEST_VERSION;
-
-    /* Test that the library is greater than our minimum version */
-    if ((xml_major_version > major) ||
-        ((xml_major_version == major) && (xml_minor_version > minor)) ||
-        ((xml_major_version == major) && (xml_minor_version == minor) &&
-        (xml_micro_version >= micro)))
-      {
-        return 0;
-       }
-     else
-      {
-        printf("\n*** An old version of libxml (%d.%d.%d) was found.\n",
-               xml_major_version, xml_minor_version, xml_micro_version);
-        printf("*** You need a version of libxml newer than %d.%d.%d.\n",
-           major, minor, micro);
-        printf("***\n");
-        printf("*** If you have already installed a sufficiently new version, this error\n");
-        printf("*** probably means that the wrong copy of the xml2-config shell script is\n");
-        printf("*** being found. The easiest way to fix this is to remove the old version\n");
-        printf("*** of LIBXML, but you can also set the XML2_CONFIG environment to point to the\n");
-        printf("*** correct copy of xml2-config. (In this case, you will have to\n");
-        printf("*** modify your LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf\n");
-        printf("*** so that the correct libraries are found at run-time))\n");
-    }
-  return 1;
-}
-]])],, no_xml=yes,[echo $ac_n "cross compiling; assumed OK... $ac_c"])
-       CPPFLAGS="$ac_save_CPPFLAGS"
-       LIBS="$ac_save_LIBS"
-     fi
-  fi
+AC_DEFUN([AM_PATH_XML2],[
+  AC_REQUIRE([PKG_PROG_PKG_CONFIG])
 
-  if test "x$no_xml" = x ; then
-     AC_MSG_RESULT(yes (version $xml_config_major_version.$xml_config_minor_version.$xml_config_micro_version))
-     ifelse([$2], , :, [$2])     
-  else
-     AC_MSG_RESULT(no)
-     if test "$XML2_CONFIG" = "no" ; then
-       echo "*** The xml2-config script installed by LIBXML could not be found"
-       echo "*** If libxml was installed in PREFIX, make sure PREFIX/bin is in"
-       echo "*** your path, or set the XML2_CONFIG environment variable to the"
-       echo "*** full path to xml2-config."
-     else
-       if test -f conf.xmltest ; then
-        :
-       else
-          echo "*** Could not run libxml test program, checking why..."
-          CPPFLAGS="$CPPFLAGS $XML_CPPFLAGS"
-          LIBS="$LIBS $XML_LIBS"
-	  AC_LINK_IFELSE(
-            [AC_LANG_PROGRAM([[
-#include <libxml/xmlversion.h>
-#include <stdio.h>
-]],    [[ LIBXML_TEST_VERSION; return 0;]])],
-        [ echo "*** The test program compiled, but did not run. This usually means"
-          echo "*** that the run-time linker is not finding LIBXML or finding the wrong"
-          echo "*** version of LIBXML. If it is not finding LIBXML, you'll need to set your"
-          echo "*** LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf to point"
-          echo "*** to the installed location  Also, make sure you have run ldconfig if that"
-          echo "*** is required on your system"
-          echo "***"
-          echo "*** If you have an old version installed, it is best to remove it, although"
-          echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH" ],
-        [ echo "*** The test program failed to compile or link. See the file config.log for the"
-          echo "*** exact error that occurred. This usually means LIBXML was incorrectly installed"
-          echo "*** or that you have moved LIBXML since it was installed. In the latter case, you"
-          echo "*** may want to edit the xml2-config script: $XML2_CONFIG" ])
-          CPPFLAGS="$ac_save_CPPFLAGS"
-          LIBS="$ac_save_LIBS"
-       fi
-     fi
+  verdep=ifelse([$1], [], [], [">= $1"])
+  PKG_CHECK_MODULES(XML, [libxml-2.0 $verdep], [$2], [$3])
 
-     XML_CPPFLAGS=""
-     XML_LIBS=""
-     ifelse([$3], , :, [$3])
-  fi
+  XML_CPPFLAGS=$XML_CFLAGS
   AC_SUBST(XML_CPPFLAGS)
-  AC_SUBST(XML_LIBS)
-  rm -f conf.xmltest
 ])
-- 
2.34.1