bux-lang/docs/BuildAndTest.md

Build and Test Guide

This guide covers building the Bux bootstrap compiler, creating projects, and running tests.

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Prerequisites

• Nim (1.6+) — for building the bootstrap compiler
• C compiler (gcc, clang, or cc) — for the C backend
• Make

On Debian/Ubuntu:

sudo apt-get install nim gcc make libssl-dev

On macOS:

brew install nim gcc make openssl

Note: The Std::Crypto module requires OpenSSL (-lcrypto). The build system links it automatically.

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Building the Compiler

# Release build
make build

# Development build (no optimizations, faster compile)
make dev

The output is a single binary: buxc (bootstrap compiler in Nim).

The self-hosted compiler buxc2 is built from src/*.bux sources via:

make selfhost

This compiles buxc2 using the bootstrap compiler. The self-hosted compiler generates C code and invokes cc to produce native binaries.

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Creating a Project

# Create a new package in a new directory
./buxc new myproject
cd myproject

# Or initialize in the current directory
mkdir myproject && cd myproject
./buxc init

This generates:

myproject/
├── bux.toml
└── src/
    └── Main.bux

bux.toml

[Package]
Name    = "myproject"
Version = "0.1.0"
Type    = "bin"

[Build]
Output = "Bin"

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Building and Running

# Type-check without building
./buxc check
./buxc check ./myproject

# Build
./buxc build
./buxc build ./myproject

# Build and run
./buxc run
./buxc run ./myproject

# Run tests (builds and runs the binary, reports pass/fail)
./buxc test
./buxc test ./myproject

# Format code
./buxc fmt src/Main.bux       # single file
./buxc fmt src/               # all .bux files in directory

# Clean build artifacts
./buxc clean

Build output goes to build/ by default.

Cross-Compilation

Use --target <triple> to cross-compile for a different platform. Bux generates C code and uses clang with the -target flag for cross-compilation.

# Cross-compile for ARM Linux
./buxc build --target aarch64-linux-gnu

# Cross-compile for x86_64 Linux (explicit)
./buxc build --target x86_64-linux-gnu

# Cross-compile and run project build
./buxc project --target x86_64-linux-gnu
./buxc run --target aarch64-linux-gnu

Note: clang must be installed for cross-compilation. Without --target, Bux uses the system cc compiler.

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Running Tests

Example suite

make test-examples   # all examples/ programs (40+)
make test-errors     # golden Rust-style diagnostic output

Compiler Tests

make test

This runs:

• Example suite (test-examples)
• Error diagnostic goldens (test-errors)
• Lexer unit tests
• Parser unit tests
• Semantic analysis unit tests
• HIR lowering unit tests
• Integration tests (buxc new, buxc --version)
• Golden C-codegen tests (8 examples)

Project Tests (bux test)

./buxc test                    # run all tests/*.bux in the current package
./buxc test --filter first     # only tests whose name contains "first"
./buxc test --filter=first _test_runner

Discovers tests/*.bux, builds each as a temp package, and runs it. Prints a summary table and exits:

• 0 — all selected tests passed
• 1 — at least one failure, or no tests matched the filter

Use Std::Test module for assertions inside test code.

Format (bux fmt)

./buxc fmt examples/hello.bux  # reformat one file
./buxc fmt lib/                # reformat a directory tree
make fmt                       # reformat lib/ examples/ src/ tests/ apps/
./buxc fmt --check path/       # exit 1 if any file would change
make fmt-check                 # CI: full-tree clean + dirty smoke

Indentation is 4 spaces by brace depth. The formatter is idempotent (safe to re-run). make fmt-check enforces a clean tree under lib/, examples/, src/, tests/, and apps/.

Stdlib golden tests

make test-stdlib
# or: tests/stdlib_golden/run.sh ./buxc

Behavioral packages under tests/stdlib_golden/ (array, string, collections) assert core Array/String/Map/Set/Result/Option APIs and match expected PASS lines.

API docs (bux doc)

./buxc doc lib/                      # Markdown to stdout
./buxc doc --out docs/api/stdlib.md lib/
make docs                            # writes docs/api/stdlib.md

Scans /// line comments (and bootstrap also accepts adjacent /* */) immediately before func / struct / enum / interface / module declarations.

Language Server (bux-lsp 0.4.0)

make lsp                             # → tools/bux-lsp
nim r --path:bootstrap tools/test_lsp_locals.nim
./tools/smoke_lsp_hover.sh

Features: diagnostics (buxc check), hover, go-to-def, outline, completion. Locals are position-sensitive (nested scopes / shadowing). Inferred let types appear on hover (let x: int · inferred).

Example Programs

make test-examples

Compiles and runs all programs in examples/.

Individual Example

mkdir -p examples_pkg/hello/src
cp examples/hello.bux examples_pkg/hello/src/Main.bux
# Create bux.toml manually or use `buxc new`
cd examples_pkg/hello && ../../buxc run

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Project Layout

bux/
├── src/              # Self-hosted compiler source (Bux)
│   ├── Main.bux      # Entry point
│   ├── Cli.bux       # CLI commands (build, run, test, fmt, new, init)
│   ├── Lexer.bux     # Tokenizer
│   ├── Parser.bux    # Parser
│   ├── Ast.bux       # AST definitions
│   ├── Sema.bux      # Semantic analysis (borrow checker)
│   ├── Types.bux     # Type system
│   ├── Scope.bux     # Symbol table
│   ├── Hir.bux       # High-level IR
│   ├── HirLower.bux  # AST → HIR lowering
│   ├── CBackend.bux  # HIR → C code generation
│   ├── Manifest.bux  # bux.toml parser
│   ├── Fmt.bux       # Code formatter
│   └── Token.bux     # Token definitions
├── bootstrap/        # Bootstrap compiler (Nim) — compiles src/ → buxc
│   ├── main.nim
│   ├── cli.nim
│   └── ...
├── lib/              # Standard library (Bux)
│   ├── Io.bux
│   ├── Array.bux
│   ├── String.bux
│   ├── Map.bux
│   ├── Fs.bux
│   ├── Mem.bux
│   ├── Set.bux
│   ├── Path.bux
│   ├── Math.bux
│   ├── Task.bux
│   └── Channel.bux
├── rt/               # C runtime
│   ├── runtime.c
│   └── io.c
├── examples/         # Example programs
├── tests/            # Unit tests (Nim)
├── docs/             # Documentation
└── Makefile

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Debugging

Verbose Output

./buxc build -v

Inspecting Generated C (bootstrap)

./buxc build
cat build/main.c

Inspecting Generated C (self-hosted)

cd src && ../buxc build
cat build/main.c

Common Errors

Error	Cause	Fix
stdlib directory not found	buxc can't find lib/	Run from project root or set correct path
duplicate symbol 'bux_alloc'	Multiple stdlib modules declare same extern	Only declare in one module
C compilation failed	Generated C has errors	Check build/main.c for issues

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Adding a New Example

1. Create examples/myexample.bux
2. Add myexample to EXAMPLES in Makefile
3. Run make test-examples

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Development Workflow

# After making changes to the compiler:
make build
make test

# If tests pass, run examples:
make test-examples