gcpug · tenntenn · Mar 29, 2019 · Mar 29, 2019
diff --git a/passes/wraperr/testdata/src/a/a.go b/passes/wraperr/testdata/src/a/a.go
@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"cloud.google.com/go/spanner"
+	"google.golang.org/grpc/status"
 )
 
 type wrapErr struct {
@@ -59,3 +60,34 @@ func f4(ctx context.Context, client *spanner.Client) {
 		return nil
 	})
 }
+
+type grpcStatusErr struct {
+	error
+}
+
+// see: https://github.com/googleapis/google-cloud-go/issues/1223
+func (*grpcStatusErr) GRPCStatus() *status.Status {
+	return nil
+}
+
+func f5(ctx context.Context, client *spanner.Client) {
+	client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
+		stmt := spanner.Statement{SQL: `SELECT 1`}
+		_, err := client.Single().Query(ctx, stmt).Next()
+		if err != nil {
+			return &grpcStatusErr{err} // OK
+		}
+		return nil
+	})
+}
+
+func f6(ctx context.Context, client *spanner.Client) {
+	client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
+		stmt := spanner.Statement{SQL: `SELECT 1`}
+		_, err := client.Single().Query(ctx, stmt).Next()
+		if err != nil {
+			return &spanner.Error{} // OK
+		}
+		return nil
+	})
+}
diff --git a/passes/wraperr/testdata/src/a/go.mod b/passes/wraperr/testdata/src/a/go.mod
@@ -2,4 +2,7 @@ module a
 
 go 1.12
 
-require cloud.google.com/go v0.37.1
+require (
+	cloud.google.com/go v0.37.1
+	google.golang.org/grpc v1.19.0
+)
diff --git a/passes/wraperr/testdata/src/a/vendor/modules.txt b/passes/wraperr/testdata/src/a/vendor/modules.txt
@@ -80,13 +80,13 @@ google.golang.org/appengine/internal/urlfetch
 # google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19
 google.golang.org/genproto/googleapis/rpc/errdetails
 google.golang.org/genproto/googleapis/spanner/v1
-google.golang.org/genproto/googleapis/api/annotations
 google.golang.org/genproto/googleapis/rpc/status
+google.golang.org/genproto/googleapis/api/annotations
 # google.golang.org/grpc v1.19.0
+google.golang.org/grpc/status
 google.golang.org/grpc
 google.golang.org/grpc/codes
 google.golang.org/grpc/metadata
-google.golang.org/grpc/status
 google.golang.org/grpc/credentials
 google.golang.org/grpc/credentials/oauth
 google.golang.org/grpc/balancer

diff --git a/passes/wraperr/wraperr.go b/passes/wraperr/wraperr.go
@@ -3,6 +3,7 @@ package wraperr
 import (
 	"go/ast"
 	"go/token"
+	"go/types"
 
 	"github.com/gcpug/zagane/zaganeutils"
 	"github.com/gostaticanalysis/analysisutil"
@@ -16,7 +17,7 @@ import (
 var Analyzer = &analysis.Analyzer{
 	Name: "wraperr",
 	Doc:  Doc,
-	Run:  run,
+	Run:  new(runner).run,
 	Requires: []*analysis.Analyzer{
 		buildssa.Analyzer,
 		commentmap.Analyzer,
@@ -25,7 +26,14 @@ var Analyzer = &analysis.Analyzer{
 
 const Doc = "wraperr finds ReadWriteTransaction calls which returns wrapped errors"
 
-func run(pass *analysis.Pass) (interface{}, error) {
+type runner struct {
+	spannerError        types.Type
+	grpcStatusInterface *types.Interface
+}
+
+func (r *runner) run(pass *analysis.Pass) (interface{}, error) {
+	r.grpcStatusInterface = newGRPCStatusInterface(pass)
+	r.spannerError = zaganeutils.TypeOf(pass, "*Error")
 	cmaps := pass.ResultOf[commentmap.Analyzer].(comment.Maps)
 	funcs := pass.ResultOf[buildssa.Analyzer].(*buildssa.SSA).SrcFuncs
 
@@ -50,7 +58,7 @@ func run(pass *analysis.Pass) (interface{}, error) {
 					continue
 				}
 
-				if pos := wrapped(instr); pos != token.NoPos {
+				if pos := r.wrapped(instr); pos != token.NoPos {
 					if !cmaps.IgnorePos(pos, "zagane") &&
 						!cmaps.IgnorePos(pos, "wraperr") {
 						pass.Reportf(pos, "must not be wrapped")
@@ -63,7 +71,7 @@ func run(pass *analysis.Pass) (interface{}, error) {
 	return nil, nil
 }
 
-func wrapped(instr ssa.Instruction) token.Pos {
+func (r *runner) wrapped(instr ssa.Instruction) token.Pos {
 	call, ok := instr.(ssa.CallInstruction)
 	if !ok {
 		return token.NoPos
@@ -80,13 +88,13 @@ func wrapped(instr ssa.Instruction) token.Pos {
 
 	switch fnc := common.Args[2].(type) {
 	case *ssa.MakeClosure:
-		return returnedWrappedErr(fnc.Fn)
+		return r.returnedWrappedErr(fnc.Fn)
 	}
 
 	return token.NoPos
 }
 
-func returnedWrappedErr(v ssa.Value) token.Pos {
+func (r *runner) returnedWrappedErr(v ssa.Value) token.Pos {
 	for _, ret := range analysisutil.Returns(v) {
 		if len(ret.Results) == 0 {
 			continue
@@ -100,6 +108,10 @@ func returnedWrappedErr(v ssa.Value) token.Pos {
 			continue
 		}
 
+		if r.implementsGRPCStatus(v) || r.isSpannerError(v) {
+			continue
+		}
+
 		if !zaganeutils.FromSpanner(v) {
 			switch v := v.(type) {
 			case *ssa.MakeInterface:
@@ -111,3 +123,37 @@ func returnedWrappedErr(v ssa.Value) token.Pos {
 	}
 	return token.NoPos
 }
+
+func (r *runner) implementsGRPCStatus(v ssa.Value) bool {
+	if r.grpcStatusInterface == nil {
+		return false
+	}
+	switch v := v.(type) {
+	case *ssa.MakeInterface:
+		return types.Implements(v.X.Type(), r.grpcStatusInterface)
+	}
+	return types.Implements(v.Type(), r.grpcStatusInterface)
+}
+
+func (r *runner) isSpannerError(v ssa.Value) bool {
+	if r.spannerError == nil {
+		return false
+	}
+	switch v := v.(type) {
+	case *ssa.MakeInterface:
+		return types.Identical(v.X.Type(), r.spannerError)
+	}
+	return types.Identical(v.Type(), r.spannerError)
+}
+
+func newGRPCStatusInterface(pass *analysis.Pass) *types.Interface {
+	typStatus := analysisutil.TypeOf(pass, "google.golang.org/grpc/status", "*Status")
+	if typStatus == nil {
+		return nil
+	}
+
+	ret := types.NewTuple(types.NewParam(token.NoPos, pass.Pkg, "", typStatus))
+	sig := types.NewSignature(nil, types.NewTuple(), ret, false)
+	grpcStatusFunc := types.NewFunc(token.NoPos, pass.Pkg, "GRPCStatus", sig)
+	return types.NewInterfaceType([]*types.Func{grpcStatusFunc}, nil).Complete()
+}