Update oid package for PostgreSQL 18.3

oid/gen.go

@@ -5,77 +5,113 @@
 package main
 
 import (
+	"bytes"
 	"database/sql"
 	"fmt"
+	"go/format"
 	"log"
 	"os"
-	"os/exec"
+	"slices"
 	"strings"
 
 	_ "github.com/lib/pq"
 	"github.com/lib/pq/internal/pqtest"
 )
 
-// OID represent a postgres Object Identifier Type.
 type OID struct {
-	ID   int
-	Type string
+	ID      int
+	Type    string
+	Comment string
 }
 
-// Name returns an upper case version of the oid type.
-func (o OID) Name() string {
-	return strings.ToUpper(o.Type)
+var extra = []OID{
+	{0, "", "Not defined by current PostgreSQL (18); kept for compatibility."},
+	{210, "smgr", ""},
+	{702, "abstime", ""},
+	{703, "reltime", ""},
+	{704, "tinterval", ""},
+	{1023, "_abstime", ""},
+	{1024, "_reltime", ""},
+	{1025, "_tinterval", ""},
+	{2282, "opaque", ""},
 }
 
 func main() {
-	db, err := sql.Open("postgres", pqtest.DSN())
+	db, err := sql.Open("postgres", pqtest.DSN(""))
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer db.Close()
 
+	var v string
+	err = db.QueryRow(`show server_version`).Scan(&v)
+	if err != nil {
+		log.Fatal(err)
+	}
+	v, _, _ = strings.Cut(v, " ")
+
 	rows, err := db.Query(`select typname, oid from pg_type where oid < 10000 order by oid`)
 	if err != nil {
 		log.Fatal(err)
 	}
-	oids := make([]*OID, 0)
+
+	oids := make([]OID, 0, 256)
 	for rows.Next() {
 		var oid OID
-		if err = rows.Scan(&oid.Type, &oid.ID); err != nil {
+		err := rows.Scan(&oid.Type, &oid.ID)
+		if err != nil {
 			log.Fatal(err)
 		}
-		oids = append(oids, &oid)
+		oids = append(oids, oid)
 	}
-	if err = rows.Err(); err != nil {
+	if err := rows.Err(); err != nil {
 		log.Fatal(err)
 	}
-	cmd := exec.Command("gofmt")
-	cmd.Stderr = os.Stderr
-	w, err := cmd.StdinPipe()
-	if err != nil {
-		log.Fatal(err)
+
+	oids = append(oids, extra...)
+
+	var (
+		consts = new(bytes.Buffer)
+		names  = new(bytes.Buffer)
+	)
+	fmt.Fprintln(consts, "const (")
+	fmt.Fprintln(names, "var TypeName = map[Oid]string{")
+	for _, oid := range oids {
+		if oid.Comment != "" {
+			fmt.Fprintf(consts, "\n// %s\n", oid.Comment)
+			fmt.Fprintf(names, "\n// %s\n", oid.Comment)
+			continue
+		}
+
+		// Special case: this was removed in in 2019 (postgres commit
+		// 91595f9d49c) and appearantly unused since 1997. However, ID 210 has
+		// since been re-used for _pg_type so we can't add this to the map.
+		//
+		// Referenced by dolthub/doltgresql: https://github.com/search?q=%22oid.T_smgr%22&type=code
+		// May also be referenced in private repos.
+		//
+		// So still add it as a constant but as alias of T__pg_type. We can't
+		// really add it to the map though, but that's okay.
+		if oid.Type == "smgr" {
+			fmt.Fprintf(consts, "T_%s Oid = T__pg_type\n", oid.Type)
+			continue
+		}
+
+		fmt.Fprintf(consts, "T_%s Oid = %d\n", oid.Type, oid.ID)
+		fmt.Fprintf(names, "T_%s: \"%s\",\n", oid.Type, strings.ToUpper(oid.Type))
 	}
-	f, err := os.Create("types.go")
+	fmt.Fprintln(consts, ")")
+	fmt.Fprintln(names, "}")
+
+	head := fmt.Sprintf(
+		"// Code generated by gen.go. DO NOT EDIT.\n\n// Last updated for PostgreSQL %s\n\npackage oid\n\n",
+		v)
+	src, err := format.Source(slices.Concat([]byte(head), consts.Bytes(), names.Bytes()))
 	if err != nil {
 		log.Fatal(err)
 	}
-	cmd.Stdout = f
-	err = cmd.Start()
+	err = os.WriteFile("types.go", src, 0o666)
 	if err != nil {
 		log.Fatal(err)
 	}
-	fmt.Fprintln(w, "// Code generated by gen.go. DO NOT EDIT.")
-	fmt.Fprintln(w, "\npackage oid")
-	fmt.Fprintln(w, "const (")
-	for _, oid := range oids {
-		fmt.Fprintf(w, "T_%s Oid = %d\n", oid.Type, oid.ID)
-	}
-	fmt.Fprintln(w, ")")
-	fmt.Fprintln(w, "var TypeName = map[Oid]string{")
-	for _, oid := range oids {
-		fmt.Fprintf(w, "T_%s: \"%s\",\n", oid.Type, oid.Name())
-	}
-	fmt.Fprintln(w, "}")
-	w.Close()
-	cmd.Wait()
 }