PHP Extension using libtidy compiles, but does not load - php

Question

I wrote an extension in C++ that uses libtidy, and it runs perfectly under PHP when I compile PHP --with-tidy.
However, it would be nice to have the extension run on a vanilla PHP. When I try to use the extension, I get something like:
PHP Warning:
PHP Startup:
Unable to load dynamic library 'extension.so':
undefined symbol: tidyCleanAndRepair in Unknown on line 0
and the extension is not loaded.
Obviously, the official tidy extension works fine. I have the relevant libtidy development packages installed on the system, and it compiles+links without a problem. I have tried to look through the code for the tidy extension, but it is a huge mass of macros - copying pieces at random felt like cargo code.
Besides linking to the library with PHP_ADD_LIBRARY_WITH_PATH(tidy, $TIDY_LIBDIR, TIDY_SHARED_LIBADD), Is there a PHP extension or C statement that fixes this error?
Thanks in advance!!
EDIT: here is the entire config.m4 file:
dnl config.m4 for extension htmlparser
PHP_ARG_ENABLE(htmlparse, whether to enable htmlparser support,
[ --enable-htmlparser Enable htmlparser support])
if test "$PHP_HTMLPARSER" != "no"; then
if test -r $PHP_LIBXML2/lib/libxml2.a; then
LIBXML2_DIR=$PHP_LIBXML2
else
AC_MSG_CHECKING(for libxml2 in default path)
for i in /usr/local /usr; do
if test -r $i/lib/libxml2.a; then
LIBXML2_DIR=$i
AC_MSG_RESULT(found in $i)
fi
done
fi
if test -z "$LIBXML2_DIR"; then
AC_MSG_RESULT(not found)
AC_MSG_ERROR(Please reinstall the libxml2 distribution - libxml2.h should
be in <libxml2-dir>/include and libxml2.a should be in <libxml2- dir>/lib)
fi
PHP_ADD_INCLUDE($LIBXML2_DIR/include/libxml2)
PHP_ADD_LIBRARY_WITH_PATH(libxml2, $LIBXML2_DIR/lib, LIBXML2_SHARED_LIBADD)
AC_MSG_CHECKING(for boost in default path)
for i in /usr/local /usr; do
if test -r $i/include/boost; then
BOOST_DIR=$i
AC_MSG_RESULT(found in $i)
fi
done
if test -z "$BOOST_DIR"; then
AC_MSG_RESULT(not found)
AC_MSG_ERROR(Please reinstall the boost distribution!!!)
fi
PHP_ADD_INCLUDE($BOOST_DIR/include/boost/)
TIDY_SEARCH_DIRS="/usr/local /usr"
for i in $TIDY_SEARCH_DIRS; do
if test -f $i/include/tidy/tidy.h; then
TIDY_DIR=$i
TIDY_INCDIR=$i/include/tidy
elif test -f $i/include/tidy.h; then
TIDY_DIR=$i
TIDY_INCDIR=$i/include
fi
done
if test -z "$TIDY_DIR"; then
AC_MSG_ERROR(Cannot find libtidy)
fi
TIDY_LIBDIR=$TIDY_DIR/lib
PHP_ADD_INCLUDE($TIDY_INCDIR)
PHP_ADD_LIBRARY_WITH_PATH(tidy, $TIDY_LIBDIR, TIDY_SHARED_LIBADD)
PHP_CHECK_LIBRARY(tidy,tidyOptGetDoc,
[
AC_DEFINE(HAVE_TIDYOPTGETDOC,1,[ ])
],[],[])
AC_DEFINE(HAVE_HTMLPARSER, 1, [Whether you want htmlparser support])
PHP_SUBST(HTMLPARSER_SHARED_LIBADD)
PHP_ADD_LIBRARY_WITH_PATH(stdc++, 1, HTMLPARSER_SHARED_LIBADD)
PHP_REQUIRE_CXX()
PHP_NEW_EXTENSION(htmlparser, php_htmlparser.cpp parsehtml.cpp StringBuilder.cpp, $ext_shared)
fi

Answer 1

did you compile your extension with the same php version as a vanilla php? you should use php sources with the same version.
besides, make sure that in php.ini file you loaded 'libtidy' extension before your extension.