Module dataflow 

Dataflow Analysis Module

This module provides two forward dataflow analyses:

1. Available Expressions Analysis (CAP-AE-01 through CAP-AE-12)

   • Forward MUST (intersection) dataflow analysis
   • Common Subexpression Elimination (CSE) detection
   • Commutative expression normalization

2. Abstract Interpretation (CAP-AI-01 through CAP-AI-22)

   • Forward dataflow with widening for loop termination
   • Range tracking for integer variables
   • Nullability tracking (NEVER/MAYBE/ALWAYS)
   • Division-by-zero detection
   • Null dereference detection
   • Multi-language support (Python, TypeScript, Go, Rust)

Module Structure

dataflow/
├── mod.rs              # This file - module entry point
├── types.rs            # Shared types (BlockId, predecessors)
├── available.rs        # Available expressions analysis
├── abstract_interp.rs  # Abstract interpretation
└── dataflow_tests.rs   # Comprehensive test suite

Usage

use tldr_core::dataflow::{
    compute_available_exprs, AvailableExprsInfo, Expression,
    compute_abstract_interp, AbstractInterpInfo, AbstractValue, Nullability,
};

// Available Expressions Analysis
let cfg = get_cfg_context(path, func, None, None)?;
let dfg = get_dfg_context(path, func, None, None)?;
let avail = compute_available_exprs(&cfg, &dfg)?;
let redundant = avail.redundant_computations();

// Abstract Interpretation
let interp = compute_abstract_interp(&cfg, &refs, Some(&source), "python")?;
for (line, var) in &interp.potential_div_zero {
    println!("Warning: potential division by zero at line {} ({})", line, var);
}

Specification Reference

See spec.md in this directory for:

• Full capability definitions (34 capabilities)
• Algorithm descriptions
• Behavioral contracts
• JSON output formats
• Edge case handling

Re-exports

pub use available::compute_available_exprs;

pub use available::compute_available_exprs_with_source;

pub use available::compute_available_exprs_with_source_and_lang;

pub use available::extract_binary_exprs_from_ast;

pub use available::extract_expressions_full;

pub use available::normalize_expression;

pub use available::AvailableExprsInfo;

pub use available::BlockExpressions;

pub use available::Confidence;

pub use available::ExprInstance;

pub use available::Expression;

pub use available::ExtractionResult;

pub use available::UncertainFinding;

pub use available::COMMUTATIVE_OPS;

pub use abstract_interp::compute_abstract_interp;

pub use abstract_interp::init_params;

pub use abstract_interp::transfer_block;

pub use abstract_interp::AbstractInterpInfo;

pub use abstract_interp::AbstractState;

pub use abstract_interp::AbstractValue;

pub use abstract_interp::ConstantValue;

pub use abstract_interp::Nullability;

pub use types::build_predecessors;

pub use types::build_successors;

pub use types::find_back_edges;

pub use types::reachable_blocks;

pub use types::reverse_postorder;

pub use types::validate_cfg;

pub use types::BlockId;

pub use types::DataflowError;

pub use types::MAX_BLOCKS;

pub use types::MAX_ITERATIONS;

Modules

abstract_interp

Abstract Interpretation Analysis

available

Available Expressions Analysis Types

types

Dataflow Analysis Foundation Types & CFG Helpers