This document introduces some key V8 concepts and provides a hello world
example to get you started with V8 code.
This document is intended for C++ programmers who want to embed the V8 JavaScript engine within a C++ application.
Let's look at a Hello World example that takes a JavaScript statement as a string argument, executes it as JavaScript code, and prints the result to standard out.
These concepts are discussed in greater detail in the [[Embedder‘s Guide|Embedder’s Guide]].
Follow the steps below to run the example yourself:
Download the V8 source code by following the [[git|Using-Git]] instructions.
This hello world example is compatible with version 5.8. You can check out this branch with git checkout -b 5.8 -t branch-heads/5.8
Create a build configuration using the helper script: tools/dev/v8gen.py x64.release
Edit the default build configuration by running gn args out.gn/x64.release
. Add two lines to your configuration: is_component_build = false
and v8_static_library = true
.
Build via ninja -C out.gn/x64.release
on a Linux x64 system to generate the correct binaries.
Compile hello-world.cc
, linking to the static libraries created in the build process. For example, on 64bit Linux using the GNU compiler:
g++ -I. -Iinclude samples/hello-world.cc -o hello-world -Wl,--start-group \ out.gn/x64.release/obj/{libv8_{base,libbase,external_snapshot,libplatform,libsampler},\ third_party/icu/libicu{uc,i18n},src/inspector/libinspector}.a \ -Wl,--end-group -lrt -ldl -pthread -std=c++0x
V8 requires its ‘startup snapshot’ to run. Copy the snapshot files to where your binary is stored: cp out.gn/x64.release/*.bin .
For more complex code, V8 will fail without an ICU data file. Copy this file as well: cp out.gn/x64.release/icudtl.dat .
Run the hello_world
executable file at the command line. For example, on Linux, still in the V8 directory, type the following at the command line: ./hello_world
You will see Hello, World!
.
Of course this is a very simple example and it‘s likely you’ll want to do more than just execute scripts as strings! For more information see the [[Embedder‘s Guide|Embedder’s Guide]]. If you are looking for an example which is in sync with master simply check out the file hello-world.cc
.