func()

in protoc-gen-go/generator/generator.go [1958:2030]

• 69 lines of code
• 22 McCabe index (conditional complexity)

func (g *Generator) generateDefaultConstants(mc *msgCtx, topLevelFields []topLevelField) {
	// Collect fields that can have defaults
	dFields := []defField{}
	for _, pf := range topLevelFields {
		if f, ok := pf.(*oneofField); ok {
			for _, osf := range f.subFields {
				dFields = append(dFields, osf)
			}
			continue
		}
		dFields = append(dFields, pf.(defField))
	}
	for _, df := range dFields {
		def := df.getProtoDef()
		if def == "" {
			continue
		}
		fieldname := g.defaultConstantName(mc.goName, df.getProtoName())
		typename := df.getGoType()
		if typename[0] == '*' {
			typename = typename[1:]
		}
		kind := "const "
		switch {
		case typename == "bool":
		case typename == "string":
			def = strconv.Quote(def)
		case typename == "[]byte":
			def = "[]byte(" + strconv.Quote(unescape(def)) + ")"
			kind = "var "
		case def == "inf", def == "-inf", def == "nan":
			// These names are known to, and defined by, the protocol language.
			switch def {
			case "inf":
				def = "math.Inf(1)"
			case "-inf":
				def = "math.Inf(-1)"
			case "nan":
				def = "math.NaN()"
			}
			if df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_FLOAT {
				def = "float32(" + def + ")"
			}
			kind = "var "
		case df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_FLOAT:
			if f, err := strconv.ParseFloat(def, 32); err == nil {
				def = fmt.Sprint(float32(f))
			}
		case df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_DOUBLE:
			if f, err := strconv.ParseFloat(def, 64); err == nil {
				def = fmt.Sprint(f)
			}
		case df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_ENUM:
			// Must be an enum.  Need to construct the prefixed name.
			obj := g.ObjectNamed(df.getProtoTypeName())
			var enum *EnumDescriptor
			if id, ok := obj.(*ImportedDescriptor); ok {
				// The enum type has been publicly imported.
				enum, _ = id.o.(*EnumDescriptor)
			} else {
				enum, _ = obj.(*EnumDescriptor)
			}
			if enum == nil {
				log.Printf("don't know how to generate constant for %s", fieldname)
				continue
			}
			def = g.DefaultPackageName(obj) + enum.prefix() + def
		}
		g.P(kind, fieldname, " ", typename, " = ", def)
		g.file.addExport(mc.message, constOrVarSymbol{fieldname, kind, ""})
	}
	g.P()
}