1 files changed, 85 insertions, 0 deletions
diff --git a/pkg/abi/flag.go b/pkg/abi/flag.go
new file mode 100644
index 000000000..dcdd66d4e
--- /dev/null
+++ b/pkg/abi/flag.go
@@ -0,0 +1,85 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package abi
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+)
+
+// A FlagSet is a slice of bit-flags and their name.
+type FlagSet []struct {
+	Flag uint64
+	Name string
+}
+
+// Parse returns a pretty version of val, using the flag names for known flags.
+// Unknown flags remain numeric.
+func (s FlagSet) Parse(val uint64) string {
+	var flags []string
+
+	for _, f := range s {
+		if val&f.Flag == f.Flag {
+			flags = append(flags, f.Name)
+			val &^= f.Flag
+		}
+	}
+
+	if val != 0 {
+		flags = append(flags, "0x"+strconv.FormatUint(val, 16))
+	}
+
+	if len(flags) == 0 {
+		// Prefer 0 to an empty string.
+		return "0x0"
+	}
+
+	return strings.Join(flags, "|")
+}
+
+// ValueSet is a map of syscall values to their name. Parse will use the name
+// or the value if unknown.
+type ValueSet map[uint64]string
+
+// Parse returns the name of the value associated with `val`. Unknown values
+// are converted to hex.
+func (s ValueSet) Parse(val uint64) string {
+	if v, ok := s[val]; ok {
+		return v
+	}
+	return fmt.Sprintf("%#x", val)
+}
+
+// ParseDecimal returns the name of the value associated with `val`. Unknown
+// values are converted to decimal.
+func (s ValueSet) ParseDecimal(val uint64) string {
+	if v, ok := s[val]; ok {
+		return v
+	}
+	return fmt.Sprintf("%d", val)
+}
+
+// ParseName returns the flag value associated with 'name'. Returns false
+// if no value is found.
+func (s ValueSet) ParseName(name string) (uint64, bool) {
+	for k, v := range s {
+		if v == name {
+			return k, true
+		}
+	}
+	return math.MaxUint64, false
+}