Native Build Module

assets/lua/native-build.fnl provides a Fennel API for native C/C++ builds through the process module.

It wraps:

• g++ via native-build.Gpp
• gcc via native-build.Gcc
• ar via native-build.Ar

Factories

(local native-build (require :native-build))

(local cxx (native-build.Gpp {:standard "c++17"
                              :optimization 2
                              :verbose false
                              :max-parallel 4}))
(local cc (native-build.Gcc {:standard "c11"}))
(local ar (native-build.Ar {}))

Compiler options

• :program override executable name/path (g++, gcc)
• :standard language standard
• :optimization optimization level (-O)
• :flags extra default flags array
• :verbose print commands when true
• :max-parallel default async compile worker cap (integer >= 1)

Project API

(local project (native-build.Project {:name "my-app"
                                      :compiler cxx
                                      :build-dir "__pysembled__"}))

(project:add-executables ["src/main.cpp" "src/feature.cpp"])
(project:add-include-directory "include")
(project:add-link-path "lib")
(project:add-dynamic-lib "m")
(project:add-static-lib "build/libfoo.a")
(project:add-compile-flag "-Wall")
(project:add-linker-flag "-pthread")

(project:build {:max-parallel 2})
;; or async:
(local token (project:build-async {:max-parallel 2}))
(token:wait)

(local result (project:run {:args ["--help"]}))

Library API

(local lib (native-build.Library {:name "libexample"
                                  :compiler cxx
                                  :archiver ar
                                  :build-dir "__pysembled__"}))

(lib:add-source "src/example.cpp")
(lib:add-header "include/example.h")
(lib:add-include-directory "include")

(local static-path (lib:build))
(local shared-path (lib:build-shared))

(local package (lib:package {:dynamic true
                             :package-dir "dist/libexample"}))

package requires at least one header and creates:

• <package-dir>/include
• <package-dir>/lib

Async Parallelism

build-to-objects-async now supports worker control:

• Compiler default: set :max-parallel on Gpp/Gcc
• Per-call override: pass :max-parallel to build-async/build-shared-async
• Validation: :max-parallel must be an integer >= 1

Behavior:

• nil means unlimited (spawn all compile jobs)
• finite value launches compile jobs up to the cap, then schedules remaining jobs as workers free up

Errors

This module fails loudly:

• Non-zero command exits throw with command, exit code, stdout, and stderr.
• Missing required inputs (e.g., no sources, missing headers for package) throw.