embed sapi unable to load tokenizer, undefined symbol zend_ce_stringable

[rcmcdonald91]

Description

Experimenting with the sample embed sapi code and build instructions from the provided readme. I also have the tokenizer extension installed. The php cli sapi works just fine. And php -m reports the tokenizer extension loaded. However, the embed sapi throws a warning about being unable to load tokenizer due to an undefined symbol, zend_ce_stringable. I suspect other extensions that utilize this class will also fail to load in the same way.

Any ideas what am I missing here? This might not be a bug (apologies if not), but I'm just not seeing what isn't being loaded to make tokenizer happy. Feels like a bug or a documentation oversight. Will poke at it some more tomorrow.

FreeBSD main, PHP 8.1.10

PHP Version

PHP 8.1.10

Operating System

FreeBSD main

[cmb69]

PHP 8.1.0

Really? If so, please try with 8.1.10 or 8.1.11.

[rcmcdonald91]

Whoops, late night typo there. I am running 8.1.10

[rcmcdonald91]

Well I'm going to have to put my foot in my mouth here...

There is one important difference here between the embed examples and my experiment here.

In my situation, I am instead building a shared library (as Plugin for App below) that is pluggable in another application (as Pluggable App below). This shared library is linked against the PHP Embed SAPI as per the README.

PHP extensions fail to load in this configuration due to missing symbols.

+---------------+
| Pluggable App |
+-------+-------+
        |dlopen/dlsym
+-------+-------+
|Plugin for App |
+---------------+
|     PHP       |
+--+---------+--+
   |         |dlopen/dlsym
+--+---+ +---+--+
| PHP  | | PHP  |
| ext1 | | ext2 |
+------+ +------+

I'm going to write a toy program to see if I can isolate this behavior.

[rcmcdonald91]

Here is a minimal repro case:

Edit: opening the test plugin OR'd with RTLD_GLOBAL fixes it (as in if ((handle = dlopen("./plugin.so", RTLD_LAZY | RTLD_GLOBAL)) == NULL)). Hmm, that's great but not great if you have no control over the "App"

app.c

#include <stdio.h>
#include <dlfcn.h>

int main(int argc, char *argv[])
{
    void *handle = NULL;
    void (*sym_from_plugin)(void);

    if ((handle = dlopen("./plugin.so", RTLD_LAZY)) == NULL)
        return (1);

    if ((sym_from_plugin = dlsym(handle, "sym_from_plugin")) == NULL)
        return (1);

    sym_from_plugin();

    dlclose(handle);

    return (0);
}

plugin.c

#include <stdio.h>
#include <sapi/embed/php_embed.h>

void sym_from_plugin(void)
{
	PHP_EMBED_START_BLOCK(0, NULL)

	php_printf(
		"Number of functions loaded: %d\n",
		zend_hash_num_elements(EG(function_table))
	);

	PHP_EMBED_END_BLOCK()
}

built using:

cc app.c -o app
cc -shared -fPIC -I/usr/local/include $(php-config --includes) -L$(php-config --prefix)/lib plugin.c -lphp -Wl,-rpath=$(php-config --prefix)/lib -o plugin.so

Output:

Warning: PHP Startup: Unable to load dynamic library 'ftp.so' (tried: /usr/local/lib/php/20210902/ftp.so (/usr/local/lib/php/20210902/ftp.so: Undefined symbol "zend_string_init_interned"), /usr/local/lib/php/20210902/ftp.so.so (Cannot open "/usr/local/lib/php/20210902/ftp.so.so")) in Unknown on line 0

Warning: PHP Startup: Unable to load dynamic library 'ssh2.so' (tried: /usr/local/lib/php/20210902/ssh2.so (/usr/local/lib/php/20210902/ssh2.so: Undefined symbol "file_globals"), /usr/local/lib/php/20210902/ssh2.so.so (Cannot open "/usr/local/lib/php/20210902/ssh2.so.so")) in Unknown on line 0

Warning: PHP Startup: Unable to load dynamic library 'tokenizer.so' (tried: /usr/local/lib/php/20210902/tokenizer.so (/usr/local/lib/php/20210902/tokenizer.so: Undefined symbol "zend_ce_stringable"), /usr/local/lib/php/20210902/tokenizer.so.so (Cannot open "/usr/local/lib/php/20210902/tokenizer.so.so")) in Unknown on line 0
Number of functions loaded: 757

[devnexen]

@rcmcdonald91 what happens if you compile your plugin with -fvisibility=hidden ?