gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/abi/flag.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package abi
    16  
    17  import (
    18  	"fmt"
    19  	"math"
    20  	"strconv"
    21  	"strings"
    22  )
    23  
    24  // A FlagSet is a slice of bit-flags and their name.
    25  type FlagSet []struct {
    26  	Flag uint64
    27  	Name string
    28  }
    29  
    30  // Parse returns a pretty version of val, using the flag names for known flags.
    31  // Unknown flags remain numeric.
    32  func (s FlagSet) Parse(val uint64) string {
    33  	var flags []string
    34  
    35  	for _, f := range s {
    36  		if val&f.Flag == f.Flag {
    37  			flags = append(flags, f.Name)
    38  			val &^= f.Flag
    39  		}
    40  	}
    41  
    42  	if val != 0 {
    43  		flags = append(flags, "0x"+strconv.FormatUint(val, 16))
    44  	}
    45  
    46  	if len(flags) == 0 {
    47  		// Prefer 0 to an empty string.
    48  		return "0x0"
    49  	}
    50  
    51  	return strings.Join(flags, "|")
    52  }
    53  
    54  // ValueSet is a map of syscall values to their name. Parse will use the name
    55  // or the value if unknown.
    56  type ValueSet map[uint64]string
    57  
    58  // Parse returns the name of the value associated with `val`. Unknown values
    59  // are converted to hex.
    60  func (s ValueSet) Parse(val uint64) string {
    61  	if v, ok := s[val]; ok {
    62  		return v
    63  	}
    64  	return fmt.Sprintf("%#x", val)
    65  }
    66  
    67  // ParseDecimal returns the name of the value associated with `val`. Unknown
    68  // values are converted to decimal.
    69  func (s ValueSet) ParseDecimal(val uint64) string {
    70  	if v, ok := s[val]; ok {
    71  		return v
    72  	}
    73  	return fmt.Sprintf("%d", val)
    74  }
    75  
    76  // ParseName returns the flag value associated with 'name'. Returns false
    77  // if no value is found.
    78  func (s ValueSet) ParseName(name string) (uint64, bool) {
    79  	for k, v := range s {
    80  		if v == name {
    81  			return k, true
    82  		}
    83  	}
    84  	return math.MaxUint64, false
    85  }