feat: add GoogleSQL support to sqlc parse

Add a googlesql dialect backed by github.com/sqlc-dev/zetajones, a pure-Go
GoogleSQL/ZetaSQL parser that passes the entire upstream googlesql parser
golden-test corpus.

New files in internal/engine/googlesql/:
- parse.go: Parser implementation using zetajones
- convert.go: AST converter from zetajones to sqlc AST
- utils.go: helpers (identifiers, string unquoting, type rendering)
- catalog.go, stdlib.go: catalog initialization
- reserved.go: reserved keywords (delegates to zetajones/token)

Covers SELECT (joins, subqueries, CTEs, set ops, window functions),
INSERT/UPDATE/DELETE (incl. THEN RETURN), CREATE/DROP/TRUNCATE TABLE, and
expressions incl. named @params (mapped to the same A_Expr shape the
PostgreSQL engine produces, so the named-parameter rewriter consumes them).
Unsupported constructs convert to ast.TODO without panicking.

Usage: sqlc parse --dialect googlesql queries.sql

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: kyleconroy

go.mod

@@ -44,6 +44,7 @@ require (
 	github.com/pingcap/failpoint v0.0.0-20240528011301-b51a646c7c86 // indirect
 	github.com/pingcap/log v1.1.0 // indirect
 	github.com/rogpeppe/go-internal v1.10.0 // indirect
+	github.com/sqlc-dev/zetajones v0.1.0 // indirect
 	github.com/wasilibs/wazero-helpers v0.0.0-20240620070341-3dff1577cd52 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect

go.sum

@@ -83,6 +83,8 @@ github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
 github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/sqlc-dev/doubleclick v1.0.0 h1:2/OApfQ2eLgcfa/Fqs8WSMA6atH0G8j9hHbQIgMfAXI=
 github.com/sqlc-dev/doubleclick v1.0.0/go.mod h1:ODHRroSrk/rr5neRHlWMSRijqOak8YmNaO3VAZCNl5Y=
+github.com/sqlc-dev/zetajones v0.1.0 h1:VeG0atx6lNABr9V2bSI5vL9DvOKTHX0XjMqWUE/rv40=
+github.com/sqlc-dev/zetajones v0.1.0/go.mod h1:dU1DxwqC6Cahbpnw16KpH1J2waWRDMdwyDSvovMZR4I=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=

internal/cmd/parse.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/sqlc-dev/sqlc/internal/engine/clickhouse"
 	"github.com/sqlc-dev/sqlc/internal/engine/dolphin"
+	"github.com/sqlc-dev/sqlc/internal/engine/googlesql"
 	"github.com/sqlc-dev/sqlc/internal/engine/postgresql"
 	"github.com/sqlc-dev/sqlc/internal/engine/sqlite"
 	"github.com/sqlc-dev/sqlc/internal/sql/ast"
@@ -31,15 +32,18 @@ Examples:
   sqlc parse --dialect sqlite queries.sql
 
   # Parse ClickHouse SQL
-  sqlc parse --dialect clickhouse queries.sql`,
+  sqlc parse --dialect clickhouse queries.sql
+
+  # Parse GoogleSQL (BigQuery, Spanner)
+  sqlc parse --dialect googlesql queries.sql`,
 	Args: cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
 		dialect, err := cmd.Flags().GetString("dialect")
 		if err != nil {
 			return err
 		}
 		if dialect == "" {
-			return fmt.Errorf("--dialect flag is required (postgresql, mysql, sqlite, or clickhouse)")
+			return fmt.Errorf("--dialect flag is required (postgresql, mysql, sqlite, clickhouse, or googlesql)")
 		}
 
 		// Determine input source
@@ -78,8 +82,11 @@ Examples:
 		case "clickhouse":
 			parser := clickhouse.NewParser()
 			stmts, err = parser.Parse(input)
+		case "googlesql":
+			parser := googlesql.NewParser()
+			stmts, err = parser.Parse(input)
 		default:
-			return fmt.Errorf("unsupported dialect: %s (use postgresql, mysql, sqlite, or clickhouse)", dialect)
+			return fmt.Errorf("unsupported dialect: %s (use postgresql, mysql, sqlite, clickhouse, or googlesql)", dialect)
 		}
 		if err != nil {
 			return fmt.Errorf("parse error: %w", err)

internal/engine/googlesql/catalog.go

@@ -0,0 +1,16 @@
+package googlesql
+
+import (
+	"github.com/sqlc-dev/sqlc/internal/sql/catalog"
+)
+
+func NewCatalog() *catalog.Catalog {
+	def := "main" // GoogleSQL has no implicit schema; use "main" as the default
+	return &catalog.Catalog{
+		DefaultSchema: def,
+		Schemas: []*catalog.Schema{
+			defaultSchema(def),
+		},
+		Extensions: map[string]struct{}{},
+	}
+}