github.com/oweisse/u-root@v0.0.0-20181109060735-d005ad25fef1/pkg/abi/flag.go (about)

     1  // Copyright 2018 Google Inc.
     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  	return strings.Join(flags, "|")
    47  }
    48  
    49  // ValueSet is a slice of syscall values and their name. Parse will replace
    50  // values that exactly match an entry with its name.
    51  type ValueSet []struct {
    52  	Value uint64
    53  	Name  string
    54  }
    55  
    56  // Parse returns the name of the value associated with `val`. Unknown values
    57  // are converted to hex.
    58  func (e ValueSet) Parse(val uint64) string {
    59  	for _, f := range e {
    60  		if val == f.Value {
    61  			return f.Name
    62  		}
    63  	}
    64  	return fmt.Sprintf("%#x", val)
    65  }
    66  
    67  // ParseName returns the flag value associated with 'name'. Returns false
    68  // if no value is found.
    69  func (e ValueSet) ParseName(name string) (uint64, bool) {
    70  	for _, f := range e {
    71  		if name == f.Name {
    72  			return f.Value, true
    73  		}
    74  	}
    75  	return math.MaxUint64, false
    76  }