I'm writing a PHP extension similar to V8JS. The goal, like V8JS, is to embed the V8 engine into PHP so I can execute sandboxed JavaScript code in PHP. (The implementation is different.)

The extension compiles fine, but when I attempt to run it I get:

PHP Warning: PHP Startup: Unable to load dynamic library '/phpdev/lib/php/extensions/debug-zts-20090626/v8php.so' - dlopen(/phpdev/lib/php/extensions/debug-zts-20090626/v8php.so, 9): Symbol not found: __ZN2v88internal8Snapshot13context_size_E
Referenced from: /phpdev/lib/php/extensions/debug-zts-20090626/v8php.so Expected in: flat namespace

PHP is compiled with the prefix /phpdev (with debug and maintainer flags).

v8 is compiled in /v8/ with gyp with the commands make dependencies and make x64 which produced /v8/out/x64.release and /v8/out/x64.debug. I soft-linked the header files from /v8/include to /phpdev/include and libv8_base.a from /v8/out/x64.release/libv8_base.a to /phpdev/lib/libv8.a.

This is my config.m4 file:

PHP_ARG_ENABLE(v8php,
[V8PHP],
[--enable-v8php      Include V8 JavaScript Engine])

if test $PHP_V8PHP != "no"; then
    SEARCH_PATH="$prefix /usr/local /usr"
    SEARCH_FOR="/include/v8.h"

    if test -r $PHP_V8PHP/$SEARCH_FOR; then
        V8_DIR=$PHP_V8PHP
    else
        AC_MSG_CHECKING([for V8 files in default path])
        for i in $SEARCH_PATH ; do
            if test -r $i/$SEARCH_FOR; then
                V8_DIR=$i
                AC_MSG_RESULT(found in $i)
            fi
        done
    fi

    if test -z "$V8_DIR"; then
        AC_MSG_RESULT([not found])
        AC_MSG_ERROR([Unable to locate V8])
    fi

    PHP_ADD_INCLUDE($V8_DIR/include)
    PHP_SUBST(V8PHP_SHARED_LIBADD)
    PHP_ADD_LIBRARY_WITH_PATH(v8, $V8_DIR/$PHP_LIBDIR, V8PHP_SHARED_LIBADD)
    PHP_REQUIRE_CXX()
    PHP_NEW_EXTENSION(v8php, v8php.cc v8_class.cc, $ext_shared)
fi

What am I doing wrong?