Module ai_synthesis 

Tier 1 AI synthesis — selective invocation, confidence gating, and decision recording (§17.2, §17.3, §17.4).

The synthesis layer augments the rule-based Tier 2 backends with AI generation at capability-gap points (§17.6) and target-flagged constructs (TargetProfile::ai_hints). It is the infrastructure half of “AI-first with deterministic fallback”:

1. Walk the AIR module and identify nodes that warrant AI synthesis. Trivial constructs (literals, arithmetic, direct calls, …) are classified as None by crate::profile::classify_node and bypass AI entirely — per §17.2 (Q3 amended, 2026-04-20).
2. For each flagged node, call the provider’s generate mode. Confidence gates acceptance (default 0.75); pinned cache replays (§17.8) bypass the threshold.
3. Run the deterministic verifier (§17.3) on accepted output. Verification lives in this crate — it never goes through the AI provider.
4. Record the accepted choice as a build-scope decision (§17.4) routed to .bock/decisions/build/.
5. On rejection, provider error, or verification failure, fall through to Tier 2 rule-based generation (preserved guarantee).

Structs

AiSynthesisDriver

Machinery driving a single-module AI synthesis pass.

SynthesisConfig

Runtime knobs for a single AI-augmented module compilation.

SynthesisStats

Aggregate counters across a synthesis pass.

Enums

SynthesisOutcome

Result of synthesizing a single flagged node.

Functions

cache_at

Convenience for callers that want to build a cache rooted at the project directory without importing bock_ai::AiCache.

needs_ai_synthesis

Returns true only when the node is flagged by target.ai_hints and matches a non-trivial crate::profile::NodeKindHint. Trivial constructs (literals, arithmetic, direct calls, variable bindings) always return false — the Q3 guarantee from the 2026-04-20 spec amendment.

synthesize_and_flush

Drives synthesis once per module and flushes the manifest writer.

verify_generated

Deterministic, provider-free verification of generated target code.