*: fix non-cgo builds

The package offers very little runtime functionality without CGO but
must be able to be depended upon without breaking cross builds.

A CI check is added, and two issues are resolved that block non-CGO
builds.

Author: raggi

.github/workflows/test-sqlite.yml

@@ -27,4 +27,7 @@ jobs:
       run: go test -v ./...
 
     - name: Race
-      run: go test -v -race ./...
+      run: go test -v -race ./...
+
+    - name: No CGO build
+      run: CGO_ENABLED=0 go install ./...

sqlite.go

@@ -1131,3 +1131,6 @@ type ConnLogger interface {
 	// Rollback is called after a rollback statement.
 	Rollback()
 }
+
+// LogCallback receives SQLite log messages.
+type LogCallback func(code sqliteh.Code, msg string)

sqlite_cgo.go

@@ -1,20 +1,15 @@
 //go:build cgo
-// +build cgo
 
 package sqlite
 
 import (
 	"github.com/tailscale/sqlite/cgosqlite"
-	"github.com/tailscale/sqlite/sqliteh"
 )
 
 func init() {
 	Open = cgosqlite.Open
 }
 
-// LogCallback receives SQLite log messages.
-type LogCallback func(code sqliteh.Code, msg string)
-
 // SetLogCallback sets the global SQLite log callback.
 // If callback is nil, logs are discarded.
 func SetLogCallback(callback LogCallback) error {

sqlite_cgo_test.go

@@ -1,5 +1,4 @@
 //go:build cgo
-// +build cgo
 
 package sqlite
 

sqlite_nocgo.go

@@ -0,0 +1,9 @@
+//go:build !cgo
+
+package sqlite
+
+// SetLogCallback sets the global SQLite log callback.
+// If callback is nil, logs are discarded.
+func SetLogCallback(callback LogCallback) error {
+	return nil
+}

sqlitepool/queryglue.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 package sqlitepool
 
 // This file contains bridging functions designed to let users of

sqlitepool/queryglue_test.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 package sqlitepool
 
 import (

sqlitepool/sqlitepool.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 // Package sqlitepool implements a pool of SQLite database connections.
 package sqlitepool
 

sqlitepool/sqlitepool_test.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 package sqlitepool
 
 import (

sqlitepool/util.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 package sqlitepool
 
 import (