pattern_set.go

Documentation: golang.org/x/arch/x86/xeddata

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package xeddata
     6  
     7  import (
     8  	"sort"
     9  	"strings"
    10  )
    11  
    12  // PatternSet wraps instruction PATTERN properties providing set operations on them.
    13  type PatternSet map[string]bool
    14  
    15  // NewPatternSet decodes pattern string into PatternSet.
    16  func NewPatternSet(pattern string) PatternSet {
    17  	pset := make(PatternSet)
    18  	for _, f := range strings.Fields(pattern) {
    19  		pset[f] = true
    20  	}
    21  	return pset
    22  }
    23  
    24  // PatternAliases is extendable map of pattern keys aliases.
    25  // Maps human-readable key to XED property.
    26  //
    27  // Used in PatternSet.Is.
    28  var PatternAliases = map[string]string{
    29  	"VEX":     "VEXVALID=1",
    30  	"EVEX":    "VEXVALID=2",
    31  	"XOP":     "VEXVALID=3",
    32  	"MemOnly": "MOD!=3",
    33  	"RegOnly": "MOD=3",
    34  }
    35  
    36  // String returns pattern printer representation.
    37  // All properties are sorted.
    38  func (pset PatternSet) String() string {
    39  	var keys []string
    40  	for k := range pset {
    41  		keys = append(keys, k)
    42  	}
    43  	sort.Strings(keys)
    44  	return strings.Join(keys, " ")
    45  }
    46  
    47  // Is reports whether set contains key k.
    48  // In contrast with direct pattern set lookup, it does
    49  // check if PatternAliases[k] is available to be used instead of k in lookup.
    50  func (pset PatternSet) Is(k string) bool {
    51  	if alias := PatternAliases[k]; alias != "" {
    52  		return pset[alias]
    53  	}
    54  	return pset[k]
    55  }
    56  
    57  // Replace inserts newKey if oldKey is defined.
    58  // oldKey is removed if insertion is performed.
    59  func (pset PatternSet) Replace(oldKey, newKey string) {
    60  	if pset[oldKey] {
    61  		pset[newKey] = true
    62  		delete(pset, oldKey)
    63  	}
    64  }
    65  
    66  // Index returns index from keys of first matching key.
    67  // Returns -1 if does not contain any of given keys.
    68  func (pset PatternSet) Index(keys ...string) int {
    69  	for i, k := range keys {
    70  		if pset[k] {
    71  			return i
    72  		}
    73  	}
    74  	return -1
    75  }
    76  
    77  // Match is like MatchOrDefault("", keyval...).
    78  func (pset PatternSet) Match(keyval ...string) string {
    79  	return pset.MatchOrDefault("", keyval...)
    80  }
    81  
    82  // MatchOrDefault returns first matching key associated value.
    83  // Returns defaultValue if no match is found.
    84  //
    85  // Keyval structure can be described as {"k1", "v1", ..., "kN", "vN"}.
    86  func (pset PatternSet) MatchOrDefault(defaultValue string, keyval ...string) string {
    87  	for i := 0; i < len(keyval); i += 2 {
    88  		key := keyval[i+0]
    89  		val := keyval[i+1]
    90  		if pset[key] {
    91  			return val
    92  		}
    93  	}
    94  	return defaultValue
    95  }
    96
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