rules_tcl

Bazel rules for building, testing, and managing Tcl applications and libraries.

Overview

rules_tcl provides a comprehensive set of Bazel rules for working with the Tcl scripting language. It supports:

• Building executables with tcl_binary
• Creating reusable libraries with tcl_library
• Writing and running tests with tcl_test
• Code quality checks with linting and formatting aspects
• Dependency management through Tcl's package system

The rules handle Tcl's package system, runfiles, and provide seamless integration with Bazel's build system.

Quick Start

Setup

rules_tcl does not ship a pre-registered toolchain — you declare the interpreter and libraries you want and register a tcl_toolchain locally. Add the following to your MODULE.bazel:

bazel_dep(name = "rules_tcl", version = "{version}")
bazel_dep(name = "tcl_lang", version = "{tcl_lang_version}")
bazel_dep(name = "bazel_skylib", version = "{bazel_skylib_version}")

tcllib_ext = use_extension("@rules_tcl//tcl:extensions.bzl", "tcllib")
use_repo(tcllib_ext, "tcllib")

register_toolchains(
    "//toolchain",
)

Then in //toolchain/BUILD.bazel:

load("@rules_tcl//tcl:tcl_toolchain.bzl", "tcl_toolchain", "tclcore_filegroup")

tclcore_filegroup(
    name = "tclcore",
    srcs = ["@tcl_lang//:tcl_core"],
)

tcl_toolchain(
    name = "tcl_toolchain",
    tclsh = "@tcl_lang//:tclsh",
    tclcore = ":tclcore",
    tcllib = "@tcllib",
    wrapper_template = "@rules_tcl//tcl/private:binary_wrapper.tpl",
    wrapper_entrypoint = "@rules_tcl//tcl/private:entrypoint.tcl",
)

toolchain(
    name = "toolchain",
    toolchain = ":tcl_toolchain",
    toolchain_type = "@rules_tcl//tcl:toolchain_type",
)

See the examples/ directory for a working setup. Users who need a custom interpreter (e.g. a vendor tool's tclsh) or a custom wrapper stub swap the corresponding attribute — see the tcl_toolchain rule doc for the full contract.

Basic Example

Create a simple Tcl executable:

load("@rules_tcl//tcl:tcl_binary.bzl", "tcl_binary")

tcl_binary(
    name = "hello",
    srcs = ["hello.tcl"],
)

Library Example

Create a reusable Tcl library:

load("@rules_tcl//tcl:tcl_library.bzl", "tcl_library")

tcl_library(
    name = "greetings",
    srcs = [
        "greet.tcl",
        "pkgIndex.tcl",  # Include to make the library available via `package require`
    ],
)

A pkgIndex.tcl is only needed when consumers will load the library with package require. Libraries without one are still available to their dependents through runfiles and can be loaded directly with source.