PHP Extension using libtidy compiles, but does not load

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

Materiality

Please provide the complete config.m4 file – Areopagus

I am new here at StackOverflow. We have already abandoned adding libtidy to the project, and I do not know if I should remove this question or not (people have favorited it). What should I do? – Materiality

@ewokker Leave it. Someone might answer. – Thuja

Thanks, in your question I've found an answer how to include boost into a module – Scrophulariaceous

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.

Episode

Thanks for the answer. As I mentioned in the comment above, the project has moved on. However, these seem like good directions to take when troubleshooting it next time. – Materiality