Three-Address Code (TAC) intermediate representation for JavaScript.

This crate provides a TAC representation for JavaScript/ECMAScript code, serving as an intermediate layer between the Control Flow Graph (CFG) and Static Single Assignment (SSA) forms in the compilation pipeline.

Three-Address Code

TAC is a linear intermediate representation where each statement performs at most one operation and uses at most three operands (typically: two sources and one destination). This form makes data flow analysis and optimization easier than working directly with the AST or CFG.

Key Types

• TFunc: A complete function in TAC form, including its control flow graph
• TCfg: The control flow graph containing basic blocks and metadata
• TBlock: A single basic block containing a sequence of statements
• TStmt: A single statement assigning a value to a left-hand side identifier
• TTerm: A block terminator (return, jump, conditional branch, etc.)
• Item: The right-hand side of an assignment (operation, literal, call, etc.)
• [LId]: A left-hand side identifier (simple variable, member access, or private field)

Example Flow

JavaScript code is transformed through these stages:

1. Parse to AST (using SWC)
2. Convert to CFG (using swc-cfg)
3. Lower to TAC (this crate)
4. Transform to SSA (using swc-ssa)

Modules

• consts: Constant evaluation and propagation
• conv: Conversion from CFG to TAC
• [lam]: Lambda (function) handling and atom resolution
• prepa: Preparation and preprocessing passes
• [rew]: Rewriting and transformation passes
• splat: Object and array spreading operations