[V8 built with gn] configure: error: could not determine libv8 version

[temuri416]

Hello there again,

Can't compile the extension:

checking for V8 Javascript Engine... yes, shared
checking for g++... g++
checking whether we are using the GNU C++ compiler... yes
checking whether g++ accepts -g... yes
checking how to run the C++ preprocessor... g++ -E
checking for C standard version... c++11
checking how to allow c++11 narrowing... -Wno-narrowing
checking for V8 version... NONE
configure: error: could not determine libv8 version

PHP5 V8 was compiled successfully following instructions at https://github.com/v8/v8/wiki/Building%20with%20GN

In #139 everything worked after I manually copied _.so files to /usr/lib/x86_64-linux-gnu/, but _gn* build is entirely different and I cannot find output *.so files anywhere.

Have you tested compiling your extension against V8 built with gn? What steps could I be missing?

Thanks!

[temuri416]

ok, I got the .so files by adding "is_component_build = true" to out.gn/x64.release/args.gn... But now I get this error:

checking for V8 version... 5.6.0
checking for libv8_libplatform.a... not found
configure: error: Please provide libv8_libplatform.a next to the libv8.so, see README.md for details
``

Any clue?

[temuri416]

another update...

after compiling v8 with "is_component_build = true" I ran the following commands:

cp out.gn/x64.release/lib*.so /usr/lib/ && cp -R include/* /usr/include
cd out.gn/x64.release/obj
ar rcsDT libv8_libplatform.a v8_libplatform/*.o
echo -e "create /usr/lib/libv8_libplatform.a\naddlib /usr/local/src/v8/out.gn/x64.release/obj/libv8_libplatform.a\nsave\nend" | sudo ar -M

After that v8js did compile with:

phpize
./configure
make && make install

However, php -m is reporting:

/usr/lib/libv8.so: undefined symbol: _ZTVN6icu_5613UnicodeStringE in Unknown on line 0

Crap... :(

[temuri416]

sorry for spamming, but this may save others a few hours :-)

I finally got everything working. The "undefined symbol" problem can be circumvented by supplying "v8_enable_i18n_support = false" in out.gn/x64.release/args.gn. It looks now as:

is_debug = false
target_cpu = "x64"
is_component_build = true
v8_enable_i18n_support = false

Not sure if this is really required, but I also updated out.gn/x64.release/v8_build_config.json with: "v8_enable_i18n_support": false.

After it compiles run commands from my previous comments and then v8js will build and report v8 version >5.6.

At this point I could not figure out how to do gn build to use system icu libraries. This link https://github.com/v8/v8/wiki/i18n%20support has instructions that are only for gyp build.

http://stackoverflow.com/questions/40091987/compiling-v8js-extension-after-v8-was-built-with-gn-build-as-opposed-to-gyp

That's it.

[stesie]

Hey, sorry for not answering earlier. Unfortunately I was too busy lately ...

anyways, thank you soooo much for figuring that out already :) I don't think we need a solution to link against system icu libraries ... yet completely disabling i18n is a bummer also. I'd appreciate if we can make it work with third-party-icu as before

[FullstackJack]

Also having trouble generating a libv8_libplatform.a file on a Ubuntu vagrant box. I have been trying with the LINUX README instructions, but will give GN a try.

[FullstackJack]

OK, GN build works with the recommended args and install steps in the SO question. The README for Linux should be updated with GN install steps since gyp is no longer supported.

[reiswindy]

Tried this on both Kubuntu and Linux Mint 18 and worked so far.

Supplied these values to args.gn

is_debug = false 
target_cpu = "x64" 
is_component_build = true

After compiling, ran the following commands:

sudo mkdir -p /opt/v8/lib && sudo mkdir -p /opt/v8/include
sudo cp out.gn/x64.release/lib*.so /opt/v8/lib/ && sudo cp -R include/* /opt/v8/include
sudo cp out.gn/x64.release/natives_blob.bin /opt/v8/lib
sudo cp out.gn/x64.release/snapshot_blob.bin /opt/v8/lib
cd out.gn/x64.release/obj
ar rcsDT libv8_libplatform.a v8_libplatform/*.o
echo -e "create /opt/v8/lib/libv8_libplatform.a\naddlib /tmp/v8/out.gn/x64.release/obj/libv8_libplatform.a\nsave\nend" | sudo ar -M`

Then:

phpize 
./configure --with-v8js=/opt/v8 
make 
make test
sudo make install

If the lib and include files are kept on their own separate folders instead of being copied to /usr/lib and /usr/include there's no need to disable i18n it seems. Didn't throw any errors when running php -m.

[temuri416]

@stesie It would be great if you could update official compile guide with the steps that we've outlined in this thread. No pressure though :)

[stesie]

@temuri416 never mind :) actually I'm already half-way through that. I've just digged a little deeper and modified config.m4 to use the system's linker to check for libv8_libplatform ... which now is able to pick up the libv8_libplatform.so file now yielded by the GN build (instead of the .a file formerly created).

For the moment, thanks to all of you pointing out how to compile with GN :-)

[duxet]

I have prepared Docker image with v8js extension from pecl and v8 5.7 built using GN: https://github.com/Strimoid/docker-php - maybe somebody will find this useful.

[temuri416]

@duxet

Can you possibly try check the behaviour I described here: #306 inside your docker?