This document describes the directory structure of this repository.
This directory structure is likely to evolve over time. For example, we might add more topic groups within public/lib and bin as the number of subdirectories increases.
The public/ directory defines the public interface to this repository. Code outside this repository should not depend on files outside of this directory. This directory should not depend on any files in this repository outside of this directory. This property ensures that code outside this repository does not transitively depend on any of the private files in this repository.
The public/build/ directory contains files that support the build systems of clients of the public/ directory.
The public/lib/ directory contains libraries (both static and dynamic) that clients can link into their processes. Many of the libraries in this directory are defined in FIDL, which are language-agnostic definitions of interprocess communication protocols. However, this directory also contains manually implemented libraries in various languages. In these cases, both the headers and source files for these libraries are included in this directory.
Libraries that are private implementation details of this repository (i.e., not part of this repository's public interface) should be in lib/ instead.
The public/dart-pkg/ directory contains Dart packages that do not have corresponding libraries in other languages. For example, this directory contains the packages that define the Fuchsia-specific interface between the Dart code and the Dart runtime.
Dart packages that have corresponding libraries in other languages should be in public/lib along side the implementations in those other languages.
The public/rust/crates/ directory contains crates used by the Rust programming language. These libraries are separate from public/lib to conform with the norms of the Rust community.
Rust code that is a private implementation detail of this repository should not be in this directory. Instead, that code should be placed analogously to code written in other languages.
The bin/ directory contains executable binaries. Typically, these binaries implement one or more of the interfaces defined in public/, but the binaries themselves are not part of the public interface of this repository.
The docs/ directory contains documentation about this repository.
The drivers/ directory contains device drivers, which are typically built as shared libraries that link against the Zircon DDK.
The examples/ directory contains code that demonstrates how to use the public interfaces exposed by this repository. This code should not be required for the system to execute correctly and should not depend on the private code in this repository.
The lib/ directory contains libraries (both static and dynamic) that are used internally by this repository. These libraries are internal implementation details of this repository and should not be used by code outside this repository.
Libraries that are part of the public interface of this repository (i.e., not private implementation details) should be in public/lib/ instead.
The go/src/ directory contains code implemented in the Go programming language. This code is separate from the rest of the code because the Go build system requires a directory named src on the path and uses the directory structure below the src directory to define the namespace for imports.