bazel-sandbox

A sandbox to experiment with bazel

Important Bazel concepts

A workspace is a directory that contains your project's source file and Bazel's build outputs.

• WORKSPACE - File that identifies the directory and its contents as a Bazel workspace. It lives at the root of the project's directory structure.
• BUILD - Files that tells Bazel how to build parts of the project. A directory within the workspace that contains a BUILD file is a package.
• A target is an instance of a build rule and it points to a specific set of source files and dependencies. A target can also point to other targets.

Build the project

To build the project, run the following command line: bazel build //main:hello-world

Note that //main:hello-world is the target label.

To test the built binary run .\bazel-bin\main\hello-world.exe on windows and bazel-bin/main/hello-world on linux.

How to use labels to reference targets

In BUILD files and at the command line, Bazel uses labels to reference targets - for example, //main:hello-world or //lib:hello-time. Their syntax is:

//path/to/package:target-name

If the target is a rule target, then path/to/package is the path to the directory containing the BUILD file, and target-name is what you named the target in the BUILD file (the name attribute). If the target is a file target, then path/to/package is the path to the root of the package, and target-name is the name of the target file, including its full path.

When referencing targets at the repository root, the package path is empty, just use //:target-name. When referencing targets within the same BUILD file, you can even skip the // workspace root identifier and just use :target-name.

Remarks

• BUILD files register targets via making calls to rules. .bzl files provide definitions for constants, rules, macros, and functions.