git.stella-ops.org/docs/hybrid-diff-patching.md

Hybrid Diff Patching (Source + Symbols + Binary)

Purpose

This document captures the product-level blueprint for hybrid diff patching:

• Source semantic edits (AST-level intent).
• Build-time symbol mapping (source ranges to binary symbols and addresses).
• Normalized binary deltas (stable and compact byte patches).
• Signed evidence bundle for policy gating and replay.

The goal is to make release decisions auditable at function granularity while remaining deterministic and offline-capable.

Review outcome (2026-02-16)

The advisory blueprint is implemented in the BinaryIndex DeltaSig pipeline.

Implemented in this sprint:

• Deterministic semantic edit scripts and source anchors.
• Canonical symbol-map contracts with build-id linkage (manifest-backed and deterministic fallback modes).
• Deterministic symbol_patch_plan and patch_manifest artifacts tied to function-level deltas and digest-linked evidence.
• DeltaSig predicate embedding of the full hybrid evidence chain.
• Fail-closed hybrid verifier checks for digest/linkage/boundary mismatches.
• Policy gates for hybrid presence, AST anchors, namespace protection, and patch byte budgets.

Known constraints:

• Semantic edits currently use deterministic text/symbol heuristics rather than language-specific AST adapters.
• Full byte-level patch replay execution remains a follow-on integration concern for Attestor/Doctor runtime workflows.

Canonical module dossier

Detailed contracts, phased implementation, and policy hooks are defined in:

• docs/modules/binary-index/hybrid-diff-stack.md

Execution sprint

Implementation planning for this advisory is tracked in:

• docs/implplan/SPRINT_20260216_001_BinaryIndex_hybrid_diff_patch_pipeline.md