The v8 bindings allow a user to execute javascript from within a go executable.
The bindings are tested to work with several recent v8 builds matching the Chrome builds 54 - 60 (see the .travis.yml file for specific versions). For example, Chrome 59 (dev branch) uses v8 5.9.211.4 when this was written.
Note that v8 releases match the Chrome release timeline: Chrome 48 corresponds to v8 4.8.*, Chrome 49 matches v8 4.9.*. You can see the table of current chrome and the associated v8 releases at:
http://omahaproxy.appspot.com/
In order for the bindings to compile correctly, one needs to:
- Compile v8 as a static library.
- Let cgo know where the library is located.
Download v8: https://github.com/v8/v8/wiki/Using%20Git
Lets say you've checked out the v8 source into $V8, go-v8 into $GO_V8 and
want to place the static v8 library into $GO_V8/libv8/. (For example,
export GO_V8=$GOPATH/src/github.com/augustoroman/v8)
Build:
make native GYPFLAGS="-Dv8_use_external_startup_data=0 -Dv8_enable_i18n_support=0 -Dv8_enable_gdbjit=0"
If build system produces a thin archive, you want to make it into a fat one:
for lib in `find out/native/obj.target/src/ -name '*.a'`;
do ar -t $lib | xargs ar rvs $lib.new && mv -v $lib.new $lib;
done
Symlink the libraries and include directory to the Go package dir:
ln -s `pwd`/out/native/obj.target/src ${GO_V8}/libv8
ln -s `pwd`/include ${GO_V8}/include
To build: (substitute in your OS X version: sw_vers -productVersion)
GYP_DEFINES="mac_deployment_target=10.11" \
make -j5 native GYPFLAGS="-Dv8_use_external_startup_data=0 -Dv8_enable_i18n_support=0 -Dv8_enable_gdbjit=0"
On MacOS, the resulting libraries contain debugging information by default (even though we've built the release version). As a result, the binaries are 30x larger, then they should be. Strip that to reduce the size of the archives (and build times!) very significantly:
strip -S out/native/libv8_*.a
Symlink the libraries and include directory to the Go package dir:
ln -s `pwd`/out/native ${GO_V8}/libv8
ln -s `pwd`/include ${GO_V8}/include
Also relevant is the v8 API release changes doc:
https://docs.google.com/document/d/1g8JFi8T_oAE_7uAri7Njtig7fKaPDfotU6huOa1alds/edit
This work is based off of several existing libraries: