/
vars.go
321 lines (301 loc) · 6.49 KB
/
vars.go
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// Copyright (c) 2017, Daniel Martí <mvdan@mvdan.cc>
// See LICENSE for licensing information
package interp
import (
"os"
"runtime"
"strconv"
"strings"
"mvdan.cc/sh/expand"
"mvdan.cc/sh/syntax"
)
type overlayEnviron struct {
parent expand.Environ
values map[string]expand.Variable
}
func (o overlayEnviron) Get(name string) expand.Variable {
if vr, ok := o.values[name]; ok {
return vr
}
return o.parent.Get(name)
}
func (o overlayEnviron) Set(name string, vr expand.Variable) {
o.values[name] = vr
}
func (o overlayEnviron) Each(f func(name string, vr expand.Variable) bool) {
o.parent.Each(f)
for name, vr := range o.values {
if !f(name, vr) {
return
}
}
}
func execEnv(env expand.Environ) []string {
list := make([]string, 0, 32)
env.Each(func(name string, vr expand.Variable) bool {
if vr.Exported {
list = append(list, name+"="+vr.String())
}
return true
})
return list
}
func (r *Runner) lookupVar(name string) expand.Variable {
if name == "" {
panic("variable name must not be empty")
}
var value interface{}
switch name {
case "#":
value = strconv.Itoa(len(r.Params))
case "@", "*":
value = r.Params
case "?":
value = strconv.Itoa(r.exit)
case "$":
value = strconv.Itoa(os.Getpid())
case "PPID":
value = strconv.Itoa(os.Getppid())
case "DIRSTACK":
value = r.dirStack
case "0":
if r.filename != "" {
value = r.filename
} else {
value = "gosh"
}
case "1", "2", "3", "4", "5", "6", "7", "8", "9":
i := int(name[0] - '1')
if i < len(r.Params) {
value = r.Params[i]
} else {
value = ""
}
}
if value != nil {
return expand.Variable{Value: value}
}
if value, e := r.cmdVars[name]; e {
return expand.Variable{Value: value}
}
if vr, e := r.funcVars[name]; e {
vr.Local = true
return vr
}
if vr, e := r.Vars[name]; e {
return vr
}
if vr := r.Env.Get(name); vr.IsSet() {
return vr
}
if runtime.GOOS == "windows" {
upper := strings.ToUpper(name)
if vr := r.Env.Get(upper); vr.IsSet() {
return vr
}
}
if r.opts[optNoUnset] {
r.errf("%s: unbound variable\n", name)
r.setErr(ShellExitStatus(1))
}
return expand.Variable{}
}
func (r *Runner) envGet(name string) string {
return r.lookupVar(name).String()
}
func (r *Runner) delVar(name string) {
vr := r.lookupVar(name)
if vr.ReadOnly {
r.errf("%s: readonly variable\n", name)
r.exit = 1
return
}
if vr.Local {
// don't overwrite a non-local var with the same name
r.funcVars[name] = expand.Variable{}
} else {
r.Vars[name] = expand.Variable{} // to not query r.Env
}
}
func (r *Runner) setVarString(name, value string) {
r.setVar(name, nil, expand.Variable{Value: value})
}
func (r *Runner) setVarInternal(name string, vr expand.Variable) {
if _, ok := vr.Value.(string); ok {
if r.opts[optAllExport] {
vr.Exported = true
}
} else {
vr.Exported = false
}
if vr.Local {
if r.funcVars == nil {
r.funcVars = make(map[string]expand.Variable)
}
r.funcVars[name] = vr
} else {
r.Vars[name] = vr
}
}
func (r *Runner) setVar(name string, index syntax.ArithmExpr, vr expand.Variable) {
cur := r.lookupVar(name)
if cur.ReadOnly {
r.errf("%s: readonly variable\n", name)
r.exit = 1
return
}
if name2, var2 := cur.Resolve(r.Env); name2 != "" {
name = name2
cur = var2
vr.NameRef = false
cur.NameRef = false
}
_, isIndexArray := cur.Value.([]string)
_, isAssocArray := cur.Value.(map[string]string)
if _, ok := vr.Value.(string); ok && index == nil {
// When assigning a string to an array, fall back to the
// zero value for the index.
if isIndexArray {
index = &syntax.Word{Parts: []syntax.WordPart{
&syntax.Lit{Value: "0"},
}}
} else if isAssocArray {
index = &syntax.Word{Parts: []syntax.WordPart{
&syntax.DblQuoted{},
}}
}
}
if index == nil {
r.setVarInternal(name, vr)
return
}
// from the syntax package, we know that value must be a string if index
// is non-nil; nested arrays are forbidden.
valStr := vr.Value.(string)
// if the existing variable is already an AssocArray, try our best
// to convert the key to a string
if isAssocArray {
amap := cur.Value.(map[string]string)
w, ok := index.(*syntax.Word)
if !ok {
return
}
k := r.literal(w)
amap[k] = valStr
cur.Value = amap
r.setVarInternal(name, cur)
return
}
var list []string
switch x := cur.Value.(type) {
case string:
list = append(list, x)
case []string:
list = x
case map[string]string: // done above
}
k := r.arithm(index)
for len(list) < k+1 {
list = append(list, "")
}
list[k] = valStr
cur.Value = list
r.setVarInternal(name, cur)
}
func (r *Runner) setFunc(name string, body *syntax.Stmt) {
if r.Funcs == nil {
r.Funcs = make(map[string]*syntax.Stmt, 4)
}
r.Funcs[name] = body
}
func stringIndex(index syntax.ArithmExpr) bool {
w, ok := index.(*syntax.Word)
if !ok || len(w.Parts) != 1 {
return false
}
switch w.Parts[0].(type) {
case *syntax.DblQuoted, *syntax.SglQuoted:
return true
}
return false
}
func (r *Runner) assignVal(as *syntax.Assign, valType string) interface{} {
prev := r.lookupVar(as.Name.Value)
if as.Naked {
return prev.Value
}
if as.Value != nil {
s := r.literal(as.Value)
if !as.Append || !prev.IsSet() {
return s
}
switch x := prev.Value.(type) {
case string:
return x + s
case []string:
if len(x) == 0 {
x = append(x, "")
}
x[0] += s
return x
case map[string]string:
// TODO
}
return s
}
if as.Array == nil {
// don't return nil, as that's an unset variable
return ""
}
elems := as.Array.Elems
if valType == "" {
if len(elems) == 0 || !stringIndex(elems[0].Index) {
valType = "-a" // indexed
} else {
valType = "-A" // associative
}
}
if valType == "-A" {
// associative array
amap := make(map[string]string, len(elems))
for _, elem := range elems {
k := r.literal(elem.Index.(*syntax.Word))
amap[k] = r.literal(elem.Value)
}
if !as.Append || !prev.IsSet() {
return amap
}
// TODO
return amap
}
// indexed array
maxIndex := len(elems) - 1
indexes := make([]int, len(elems))
for i, elem := range elems {
if elem.Index == nil {
indexes[i] = i
continue
}
k := r.arithm(elem.Index)
indexes[i] = k
if k > maxIndex {
maxIndex = k
}
}
strs := make([]string, maxIndex+1)
for i, elem := range elems {
strs[indexes[i]] = r.literal(elem.Value)
}
if !as.Append || !prev.IsSet() {
return strs
}
switch x := prev.Value.(type) {
case string:
return append([]string{x}, strs...)
case []string:
return append(x, strs...)
case map[string]string:
// TODO
}
return strs
}