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package pkglint
import "strings"
// MkToken represents a contiguous string from a Makefile.
// It is either a literal string or a variable use.
//
// Example: /usr/share/${PKGNAME}/data consists of 3 tokens:
// 1. MkToken{Text: "/usr/share/"}
// 2. MkToken{Text: "${PKGNAME}", Varuse: &MkVarUse{varname: "PKGNAME"}}
// 3. MkToken{Text: "/data"}
//
type MkToken struct {
Text string // Used for both literal text and variable uses
Varuse *MkVarUse // For literal text, it is nil
}
// MkVarUse represents a reference to a Make variable, with optional modifiers.
//
// For nested variable expressions, the variable name can contain references
// to other variables. For example, ${TOOLS.${t}} is a MkVarUse with varname
// "TOOLS.${t}" and no modifiers.
//
// Example: ${PKGNAME}
//
// Example: ${PKGNAME:S/from/to/}
type MkVarUse struct {
varname string // E.g. "PKGNAME", or "${BUILD_DEFS}"
modifiers []MkVarUseModifier // E.g. "Q", "S/from/to/"
}
func (vu *MkVarUse) String() string { return sprintf("${%s%s}", vu.varname, vu.Mod()) }
type MkVarUseModifier struct {
Text string
}
func (m MkVarUseModifier) IsQ() bool { return m.Text == "Q" }
func (m MkVarUseModifier) IsSuffixSubst() bool {
// XXX: There are other cases
return hasPrefix(m.Text, "=")
}
func (m MkVarUseModifier) MatchSubst() (ok bool, regex bool, from string, to string, options string) {
p := NewMkLexer(m.Text, nil)
return p.varUseModifierSubst('}')
}
// Subst evaluates an S/from/to/ modifier.
//
// Example:
// MkVarUseModifier{"S,name,file,g"}.Subst("distname-1.0") => "distfile-1.0"
func (m MkVarUseModifier) Subst(str string) (string, bool) {
// XXX: The call to MatchSubst is usually redundant because MatchSubst
// is typically called directly before calling Subst.
ok, regex, from, to, options := m.MatchSubst()
if !ok {
return "", false
}
leftAnchor := hasPrefix(from, "^")
if leftAnchor {
from = from[1:]
}
rightAnchor := hasSuffix(from, "$")
if rightAnchor {
from = from[:len(from)-1]
}
if regex && matches(from, `^[\w-]+$`) && matches(to, `^[^&$\\]*$`) {
// The "from" pattern is so simple that it doesn't matter whether
// the modifier is :S or :C, therefore treat it like the simpler :S.
regex = false
}
if regex {
// TODO: Maybe implement regular expression substitutions later.
return "", false
}
result := mkopSubst(str, leftAnchor, from, rightAnchor, to, options)
if trace.Tracing && result != str {
trace.Stepf("Subst: %q %q => %q", str, m.Text, result)
}
return result, true
}
// MatchMatch tries to match the modifier to a :M or a :N pattern matching.
// Examples:
// :Mpattern => true, true, "pattern", true
// :M* => true, true, "*", false
// :M${VAR} => true, true, "${VAR}", false
// :Npattern => true, false, "pattern", true
// :X => false
func (m MkVarUseModifier) MatchMatch() (ok bool, positive bool, pattern string, exact bool) {
if hasPrefix(m.Text, "M") || hasPrefix(m.Text, "N") {
// See devel/bmake/files/str.c:^Str_Match
exact := !strings.ContainsAny(m.Text[1:], "*?[\\$")
return true, m.Text[0] == 'M', m.Text[1:], exact
}
return false, false, "", false
}
func (m MkVarUseModifier) IsToLower() bool { return m.Text == "tl" }
// ChangesWords returns true if applying this modifier to a list variable
// may change the number of words in the list, or their boundaries.
func (m MkVarUseModifier) ChangesWords() bool {
text := m.Text
// See MkParser.varUseModifier for the meaning of these modifiers.
switch text[0] {
case 'E', 'H', 'M', 'N', 'O', 'R', 'T':
return false
case 'C', 'Q', 'S':
// For the :C and :S modifiers, a more detailed analysis could reveal
// cases that don't change the structure, such as :S,a,b,g or
// :C,[0-9A-Za-z_],.,g, but not :C,x,,g.
return true
}
switch text {
case "tl", "tu":
return false
case "sh", "tW", "tw":
return true
}
// If in doubt, be pessimistic. As of March 2019, the only code that
// actually uses this function doesn't issue a possibly wrong warning
// in such a case.
return true
}
func (vu *MkVarUse) Mod() string {
var mod strings.Builder
for _, modifier := range vu.modifiers {
mod.WriteString(":")
mod.WriteString(modifier.Text)
}
return mod.String()
}
// IsExpression returns whether the varname is interpreted as an expression
// instead of a variable name (rare, only the modifiers :? and :L do this).
func (vu *MkVarUse) IsExpression() bool {
if len(vu.modifiers) == 0 {
return false
}
mod := vu.modifiers[0]
return mod.Text == "L" || hasPrefix(mod.Text, "?")
}
func (vu *MkVarUse) IsQ() bool {
mlen := len(vu.modifiers)
return mlen > 0 && vu.modifiers[mlen-1].IsQ()
}
func (vu *MkVarUse) HasModifier(prefix string) bool {
for _, mod := range vu.modifiers {
if hasPrefix(mod.Text, prefix) {
return true
}
}
return false
}
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