Adds DuckDB 2.0 support to sqlc parse and sqlc analyze through darkwing v0.1.0, the pure Go port of DuckDB 2.0's PEG parser.

Engine (internal/engine/duckdb)

• parse.go wraps darkwing/parser. darkwing guarantees statement byte spans that tile the input — each statement starts where the previous one ended — so StmtLocation/StmtLen carry the leading -- name: annotation comments without the hand-rolled semicolon scanner the other engines need. Parse failures are wrapped as sqlerr.Error with darkwing's byte-accurate offsets, so analyze reports DuckDB's native message at the right file:line:col.
• convert.go maps darkwing's AST onto sqlc's: SELECT (CTEs incl. recursive, n-ary set operations, VALUES desugaring, window functions, ORDER BY/LIMIT/DISTINCT modifiers), INSERT/UPDATE/DELETE/TRUNCATE with RETURNING and ON CONFLICT, and the DDL the catalog consumes (CREATE TABLE, CTAS, CREATE VIEW, CREATE TYPE AS ENUM, ALTER TABLE, DROP). Parameters arrive pre-numbered by darkwing across all three spellings ($1, ?, $name); named parameters share one number per name. Identifiers are lowercased (DuckDB is case-insensitive but case-preserving) and the default main schema maps to the catalog's default namespace.
• reserved.go answers reserved-keyword checks from the keyword lists darkwing vendors from DuckDB itself.

Generated dialect seeds (internal/tools/sqlc-duckdb-gen)

Like sqlc-pg-gen, the dialect files are generated from a live database rather than written by hand: the new tool runs the pinned DuckDB CLI (v2.0.0-alpha38195 (Cyanoptera) 8cbdaba6ac, the same nightly darkwing's grammar is pinned to) and dumps duckdb_types() / duckdb_functions() into:

• types.jsonl — 40 types with their alias spellings (e.g. varchar ⇐ text, string, json, …), categorized for the seed's category-driven operators and casts
• functions.jsonl — 2,626 scalar/aggregate/window/macro signatures; generic parameters (ANY, T, K, V) map onto a seeded any type so the analyzer's polymorphic return resolution types min, max, first_value, lag, … from their arguments
• operators.jsonl — 157 binary operators taken from DuckDB's operator-named functions (~~, ||, //, …)

Only dialect.json is authored by hand. Regenerate with DUCKDB=/path/to/duckdb go run ./internal/tools/sqlc-duckdb-gen.

Wiring

config.EngineDuckDB; the compiler routes DuckDB through the core analyzer unconditionally (like ClickHouse/GoogleSQL/MSSQL there is no legacy path, and no database is needed); --dialect duckdb in both commands; docs updated.

Tests

Five end-to-end cases with committed goldens, all passing under TestReplay/base:

• parse_basic/duckdb
• analyze_basic/duckdb
• analyze_params/duckdb — $1, $name and ? spellings
• analyze_dml/duckdb — INSERT VALUES/RETURNING, UPDATE, DELETE USING, INSERT…SELECT
• analyze_select/duckdb — star expansion, count(*), joins, CTE + GROUP BY

Known v1 limits, consistent with the other core-only engines: PIVOT/DESCRIBE/COLUMNS(...) and star EXCLUDE/REPLACE convert to TODO nodes, and sqlc macro syntax (sqlc.arg() etc.) is not yet preprocessed for DuckDB.

🤖 Generated with Claude Code

https://claude.ai/code/session_016uPxbu16EDkadTKbWwHUiE

Generated by Claude Code