*: add error trace (pingcap#1477)

driver.go

@@ -245,7 +245,7 @@ func newDriverConn(sess *session, d *sqlDriver, schema string, params *driverPar
 func (c *driverConn) Prepare(query string) (driver.Stmt, error) {
 	stmtID, paramCount, fields, err := c.s.PrepareStmt(query)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	s := &driverStmt{
 		conn:       c,

plan/expression_rewriter.go

@@ -92,7 +92,7 @@ func constructBinaryOpFunction(l expression.Expression, r expression.Expression,
 		var err error
 		funcs[i], err = constructBinaryOpFunction(getRowArg(l, i), getRowArg(r, i), op)
 		if err != nil {
-			return nil, err
+			return nil, errors.Trace(err)
 		}
 	}
 	return expression.ComposeCNFCondition(funcs), nil

server/driver_tidb.go

@@ -60,7 +60,7 @@ func (ts *TiDBStatement) ID() int {
 func (ts *TiDBStatement) Execute(args ...interface{}) (rs ResultSet, err error) {
 	tidbRecordset, err := ts.ctx.session.ExecutePreparedStmt(ts.id, args...)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	if tidbRecordset == nil {
 		return
@@ -116,7 +116,7 @@ func (qd *TiDBDriver) OpenCtx(connID uint64, capability uint32, collation uint8,
 	if dbname != "" {
 		_, err := session.Execute("use " + dbname)
 		if err != nil {
-			return nil, err
+			return nil, errors.Trace(err)
 		}
 	}
 	tc := &TiDBContext{

session.go

@@ -481,7 +481,7 @@ func checkArgs(args ...interface{}) error {
 func (s *session) ExecutePreparedStmt(stmtID uint32, args ...interface{}) (ast.RecordSet, error) {
 	err := checkArgs(args...)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	st := executor.CompileExecutePreparedStmt(s, stmtID, args...)
 	r, err := runStmt(s, st, args...)
@@ -626,7 +626,7 @@ func CreateSession(store kv.Storage) (Session, error) {
 	}
 	domain, err := domap.Get(store)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	sessionctx.BindDomain(s, domain)
 

store/localstore/boltdb/boltdb.go

@@ -179,21 +179,21 @@ func (driver Driver) Open(dbPath string) (engine.DB, error) {
 
 	d, err := bolt.Open(dbPath, 0600, nil)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 
 	tx, err := d.Begin(true)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 
 	if _, err = tx.CreateBucketIfNotExists(bucketName); err != nil {
 		tx.Rollback()
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 
 	if err = tx.Commit(); err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 
 	return &db{d}, nil

store/localstore/local_client.go

@@ -3,6 +3,7 @@ package localstore
 import (
 	"io"
 
+	"github.com/juju/errors"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tipb/go-tipb"
 )
@@ -132,7 +133,7 @@ func (it *response) Next() (resp io.ReadCloser, err error) {
 	}
 	if err != nil {
 		it.Close()
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	if len(regionResp.newStartKey) != 0 {
 		it.client.updateRegionInfo()

store/tikv/coprocessor.go

@@ -293,7 +293,7 @@ func (it *copIterator) Next() (io.ReadCloser, error) {
 	defer it.mu.Unlock()
 	if err != nil {
 		it.Close()
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	it.respGot++
 	if it.respGot == len(it.tasks) {

store/tikv/mock-tikv/mvcc.go

@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"sync"
 
+	"github.com/juju/errors"
 	"github.com/petar/GoLLRB/llrb"
 	"github.com/pingcap/kvproto/pkg/kvrpcpb"
 )
@@ -328,7 +329,7 @@ func (s *MvccStore) CommitThenGet(key []byte, lockTS, commitTS, getTS uint64) ([
 	entry := s.getOrNewEntry(key)
 	err := entry.Commit(lockTS, commitTS)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	s.submit(entry)
 	return entry.Get(getTS)
@@ -374,7 +375,7 @@ func (s *MvccStore) RollbackThenGet(key []byte, lockTS uint64) ([]byte, error) {
 	entry := s.getOrNewEntry(key)
 	err := entry.Rollback(lockTS)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	s.submit(entry)
 	return entry.Get(lockTS)

util/mock/context.go

@@ -17,6 +17,7 @@ package mock
 import (
 	"fmt"
 
+	"github.com/juju/errors"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/sessionctx/variable"
@@ -62,7 +63,7 @@ func (c *Context) GetTxn(forceNew bool) (kv.Transaction, error) {
 	if forceNew {
 		err = c.CommitTxn()
 		if err != nil {
-			return nil, err
+			return nil, errors.Trace(err)
 		}
 		c.txn, err = c.Store.Begin()
 		return c.txn, err

util/testkit/testkit.go

@@ -71,19 +71,19 @@ func (tk *TestKit) Exec(sql string, args ...interface{}) (ast.RecordSet, error)
 		if err == nil && len(rss) > 0 {
 			return rss[0], nil
 		}
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	stmtID, _, _, err := tk.Se.PrepareStmt(sql)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	rs, err := tk.Se.ExecutePreparedStmt(stmtID, args...)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	err = tk.Se.DropPreparedStmt(stmtID)
 	if err != nil {
-		return nil, err
+		return nil, errors.Trace(err)
 	}
 	return rs, nil
 }