codgen/golang: Use p[gq]type for network address types (#1142)

* codgen/golang: pgtype for network address types
* codgen/golang: Use pqtype for lib/pq

Author: kyleconroy

internal/codegen/golang/driver.go

@@ -0,0 +1,18 @@
+package golang
+
+import "github.com/kyleconroy/sqlc/internal/config"
+
+type SQLDriver int
+
+const (
+	SQLDriverPGXV4 SQLDriver = iota
+	SQLDriverLibPQ
+)
+
+func parseDriver(settings config.CombinedSettings) SQLDriver {
+	if settings.Go.SQLPackage == "pgx/v4" {
+		return SQLDriverPGXV4
+	} else {
+		return SQLDriverLibPQ
+	}
+}

internal/codegen/golang/imports.go

@@ -132,6 +132,18 @@ var stdlibTypes = map[string]string{
 	"net.HardwareAddr": "net",
 }
 
+var pgtypeTypes = map[string]struct{}{
+	"pgtype.CIDR":    {},
+	"pgtype.Inet":    {},
+	"pgtype.Macaddr": {},
+}
+
+var pqtypeTypes = map[string]struct{}{
+	"pqtype.CIDR":    {},
+	"pqtype.Inet":    {},
+	"pqtype.Macaddr": {},
+}
+
 func buildImports(settings config.CombinedSettings, queries []Query, uses func(string) bool) (map[string]struct{}, map[ImportSpec]struct{}) {
 	pkg := make(map[ImportSpec]struct{})
 	std := make(map[string]struct{})
@@ -158,6 +170,18 @@ func buildImports(settings config.CombinedSettings, queries []Query, uses func(s
 		}
 	}
 
+	for typeName, _ := range pgtypeTypes {
+		if uses(typeName) {
+			pkg[ImportSpec{Path: "github.com/jackc/pgtype"}] = struct{}{}
+		}
+	}
+
+	for typeName, _ := range pqtypeTypes {
+		if uses(typeName) {
+			pkg[ImportSpec{Path: "github.com/tabbed/pqtype"}] = struct{}{}
+		}
+	}
+
 	overrideTypes := map[string]string{}
 	for _, o := range settings.Overrides {
 		if o.GoBasicType || o.GoTypeName == "" {

internal/codegen/golang/postgresql_type.go

@@ -12,6 +12,7 @@ import (
 func postgresType(r *compiler.Result, col *compiler.Column, settings config.CombinedSettings) string {
 	columnType := col.DataType
 	notNull := col.NotNull || col.IsArray
+	driver := parseDriver(settings)
 
 	switch columnType {
 	case "serial", "serial4", "pg_catalog.serial4":
@@ -108,11 +109,35 @@ func postgresType(r *compiler.Result, col *compiler.Column, settings config.Comb
 		}
 		return "uuid.NullUUID"
 
-	case "inet", "cidr":
-		return "net.IP"
+	case "inet":
+		switch driver {
+		case SQLDriverPGXV4:
+			return "pgtype.Inet"
+		case SQLDriverLibPQ:
+			return "pqtype.Inet"
+		default:
+			return "interface{}"
+		}
+
+	case "cidr":
+		switch driver {
+		case SQLDriverPGXV4:
+			return "pgtype.CIDR"
+		case SQLDriverLibPQ:
+			return "pqtype.CIDR"
+		default:
+			return "interface{}"
+		}
 
 	case "macaddr", "macaddr8":
-		return "net.HardwareAddr"
+		switch driver {
+		case SQLDriverPGXV4:
+			return "pgtype.Macaddr"
+		case SQLDriverLibPQ:
+			return "pqtype.Macaddr"
+		default:
+			return "interface{}"
+		}
 
 	case "ltree", "lquery", "ltxtquery":
 		// This module implements a data type ltree for representing labels