Fix enhance method error when unknown parameter type (#160)

CHANGES.md

@@ -17,7 +17,8 @@ Release Notes.
 * Fix users can not use async api in toolkit-trace.
 * Fix cannot enhance the vendor management project.
 * Fix SW_AGENT_REPORTER_GRPC_MAX_SEND_QUEUE not working on metricsSendCh & logSendCh chans of gRPC reporter.
-* Fix ParseVendorModule error for special case in vendor/modules.txt
+* Fix ParseVendorModule error for special case in vendor/modules.txt.
+* Fix enhance method error when unknown parameter type.
 
 #### Issues and PR
 - All issues are [here](https://github.com/apache/skywalking/milestone/197?closed=1)

tools/go-agent/instrument/plugins/templates/method_intercept_after.tmpl

@@ -21,7 +21,8 @@ if (invocation.isContinue) {
 	if invocation.returnValues[{{$index}}] != nil {
         *ret_{{$index}} = (invocation.returnValues[{{$index}}]).({{$value.PackagedTypeName}})
     } else {
-        *ret_{{$index}} = {{$value.DefaultValueAsString}}
+        var tmp_{{$index}} {{$value.PackagedTypeName}}
+        *ret_{{$index}} = tmp_{{$index}}
     }
     {{- end }}
 }

tools/go-agent/instrument/plugins/templates/method_intercept_before.tmpl

@@ -25,18 +25,21 @@ invocation.changeArgCallback = func(index int, value interface{}) {
     panic("cannot found the argument index")
 }
 
+{{- range $index, $value := .Results }}
+var def_res_{{$index}} {{$value.PackagedTypeName}}
+{{- end}}
 // real invoke
 if err := {{.InterceptorVarName}}.BeforeInvoke(invocation); err != nil {
 	// using go2sky log error
 	log.Warnf("execute interceptor before invoke error, instrument name: %s, interceptor name: %s, function ID: %s, error: %v",
     		    "{{.InstrumentName}}", "{{.InterceptorDefineName}}", "{{.FuncID}}", err)
+
 	return {{ range $index, $value := .Results -}}
-{{$value.DefaultValueAsString}},
+def_res_{{$index}},
 {{- end}}invocation, false
 }
 if (invocation.isContinue) {
     {{- range $index, $value := .Results }}
-    var def_res_{{$index}} {{$value.PackagedTypeName}}
     if invocation.returnValues[{{$index}}] != nil {
         def_res_{{$index}} = (invocation.returnValues[{{$index}}]).({{$value.PackagedTypeName}})
     }
@@ -46,5 +49,5 @@ if (invocation.isContinue) {
 {{- end}}invocation, true
 }
 return {{ range $index, $value := .Results -}}
-{{- if ne $index 0}}, {{end}}{{$value.DefaultValueAsString }}
-{{- end}}{{if .Results}}, {{- end}}invocation, false
+def_res_{{$index}},
+{{- end}}invocation, false

tools/go-agent/tools/enhancement.go

@@ -19,8 +19,6 @@ package tools
 
 import (
 	"fmt"
-	"go/token"
-	"strings"
 
 	"github.com/dave/dst"
 	"github.com/dave/dst/decorator"
@@ -31,10 +29,9 @@ const OtherPackageRefPrefix = "swref_"
 const parameterAppender = ", "
 
 type ParameterInfo struct {
-	Name                 string
-	Type                 dst.Expr
-	DefaultValueAsString string
-	TypeName             string
+	Name     string
+	Type     dst.Expr
+	TypeName string
 }
 
 type PackagedParameterInfo struct {
@@ -141,24 +138,6 @@ func newParameterInfo(name string, tp dst.Expr) *ParameterInfo {
 		Type:     tp,
 		TypeName: GenerateTypeNameByExp(tp),
 	}
-	var defaultNil = "nil"
-	switch n := tp.(type) {
-	case *dst.Ident:
-		if n.Name == "string" {
-			defaultNil = `""`
-		} else if n.Name == "bool" {
-			defaultNil = "false"
-		} else if strings.HasPrefix(n.Name, "int") || strings.HasPrefix(n.Name, "uint") ||
-			strings.HasPrefix(n.Name, "float") || n.Name == "byte" || n.Name == "rune" {
-			defaultNil = "0"
-		}
-	case *dst.UnaryExpr:
-		if n.Op == token.INT || n.Op == token.FLOAT {
-			defaultNil = "0"
-		}
-	}
-	result.DefaultValueAsString = defaultNil
-
 	return result
 }
 

tools/go-agent/tools/enhancement_test.go

@@ -23,11 +23,10 @@ import (
 	"github.com/dave/dst"
 )
 
-func buildParameterValidateInfo(name, typeName, defaultValue string) *ParameterInfo {
+func buildParameterValidateInfo(name, typeName string) *ParameterInfo {
 	return &ParameterInfo{
-		Name:                 name,
-		TypeName:             typeName,
-		DefaultValueAsString: defaultValue,
+		Name:     name,
+		TypeName: typeName,
 	}
 }
 
@@ -43,27 +42,27 @@ func TestEnhanceParameterNames(t *testing.T) {
 				return false
 			}`,
 			recvs: []*ParameterInfo{
-				buildParameterValidateInfo("skywalking_recv_0", "*Example", "nil"),
+				buildParameterValidateInfo("skywalking_recv_0", "*Example"),
 			},
 			params: []*ParameterInfo{
-				buildParameterValidateInfo("skywalking_param_0", "int", "0"),
+				buildParameterValidateInfo("skywalking_param_0", "int"),
 			},
 			results: []*ParameterInfo{
-				buildParameterValidateInfo("skywalking_result_0", "bool", "false"),
+				buildParameterValidateInfo("skywalking_result_0", "bool"),
 			},
 		},
 		{
 			funcCode: `func (e *Example) Test(i int) (b bool) {
 				return false
 }`,
 			recvs: []*ParameterInfo{
-				buildParameterValidateInfo("e", "*Example", "nil"),
+				buildParameterValidateInfo("e", "*Example"),
 			},
 			params: []*ParameterInfo{
-				buildParameterValidateInfo("i", "int", "0"),
+				buildParameterValidateInfo("i", "int"),
 			},
 			results: []*ParameterInfo{
-				buildParameterValidateInfo("b", "bool", "false"),
+				buildParameterValidateInfo("b", "bool"),
 			},
 		},
 	}
@@ -95,8 +94,5 @@ func validateParameterInfo(t *testing.T, inx int, flistType FieldListType, actua
 		if exp.TypeName != act.TypeName {
 			t.Errorf("case %d:%s: expected type %s , actual %s", inx, flistType, exp.TypeName, act.TypeName)
 		}
-		if exp.DefaultValueAsString != act.DefaultValueAsString {
-			t.Errorf("case %d:%s: expected default value %s , actual %s", inx, flistType, exp.DefaultValueAsString, act.DefaultValueAsString)
-		}
 	}
 }