Compiler Module

The compiler builds a linked, self-contained TypeGraph from .ato sources. Export/manufacturing artifacts are handled later by build steps/exporters; the compiler’s job is parsing + typegraph construction + linking.

Start with:

• src/atopile/compiler/README.md (stage overview + example usage)
• src/atopile/compiler/parser/README.md (how to regenerate ANTLR output)

Quick Start

Build a single .ato file into a linked TypeGraph (and instantiate its entrypoint):

import faebryk.core.faebrykpy as fbrk
import faebryk.core.graph as graph
import faebryk.core.node as fabll
from atopile.compiler.build import Linker, StdlibRegistry, build_file
from atopile.compiler.deferred_executor import DeferredExecutor
from atopile.config import config

g = graph.GraphView.create()
tg = fbrk.TypeGraph.create(g=g)
stdlib = StdlibRegistry(tg)
linker = Linker(config, stdlib, tg)

result = build_file(g=g, tg=tg, import_path="app.ato", path="path/to/app.ato")
linker.link_imports(g=g, state=result.state)
DeferredExecutor(g=g, tg=tg, state=result.state, visitor=result.visitor).execute()

app_type = result.state.type_roots["ENTRYPOINT"]
app_root = tg.instantiate_node(type_node=app_type, attributes={})
app = fabll.Node.bind_instance(app_root)

Relevant Files

• Core pipeline:

- src/atopile/compiler/build.py (buildfile, buildsource, Linker, StdlibRegistry, stage helpers) - src/atopile/compiler/parse.py (ANTLR parse + error listener → UserSyntaxError) - src/atopile/compiler/antlrvisitor.py (ANTLR CST → internal AST graph with source info) - src/atopile/compiler/astvisitor.py (AST → TypeGraph “preliminary” construction) - src/atopile/compiler/gentypegraph.py (typegraph generation utilities + import refs) - src/atopile/compiler/deferred_executor.py (terminal stage: inheritance/retypes/for-loops)

• Parser frontend:

- src/atopile/compiler/parser/ (AtoLexer.g4, AtoParser.g4, generated Python)

Dependants (Call Sites)

• CLI (src/atopile/cli/build.py): Calls the compiler to build the project.
• LSP (src/atopile/lsp/lsp_server.py): Builds per-document graphs and keeps the last successful result for completions/hover.

How to Work With / Develop / Test

Core Concepts

• ANTLR front-end: parse .ato into an ANTLR parse tree; syntax errors are converted to UserSyntaxError.
• AST graph: ANTLRVisitor converts ANTLR output into internal AST nodes (FabLL nodes with source info).
• TypeGraph build: AST visitor emits a preliminary TypeGraph.
• Linking: Linker resolves imports, executes inheritance ordering, applies retypes, and prepares a self-contained compilation unit.
• Deferred execution (terminal): DeferredExecutor.execute() runs operations that require resolved types (inheritance, retypes, for-loops).

Development Workflow

1. Grammar changes:

- edit src/atopile/compiler/parser/AtoLexer.g4 / AtoParser.g4 - regenerate (see src/atopile/compiler/parser/README.md)

1. Language features:

- CST → AST: src/atopile/compiler/antlrvisitor.py - AST → TypeGraph: src/atopile/compiler/astvisitor.py / gentypegraph.py

1. Linking/terminal behavior:

- src/atopile/compiler/build.py / src/atopile/compiler/deferred_executor.py

Testing

• Compiler tests: ato dev test --llm test/compiler -q
• Linker behavior: ato dev test --llm test/compiler/test_linker.py -q
• End-to-end smoke: ato dev test --llm test/testendto_end.py -q

Best Practices

• Keep errors source-attached: raise DslRichException/UserException with AST source info when possible.
• Watch graph lifetimes: most entrypoints accept (g, tg) explicitly; ensure you destroy GraphView in long-running processes (LSP does this).