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bee/vendor/github.com/derekparker/delve/service/debugger/locations.go
2017-03-26 16:55:28 +02:00

412 lines
9.8 KiB
Go

package debugger
import (
"debug/gosym"
"fmt"
"go/constant"
"path/filepath"
"reflect"
"runtime"
"strconv"
"strings"
"github.com/derekparker/delve/proc"
"github.com/derekparker/delve/service/api"
)
const maxFindLocationCandidates = 5
type LocationSpec interface {
Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error)
}
type NormalLocationSpec struct {
Base string
FuncBase *FuncLocationSpec
LineOffset int
}
type RegexLocationSpec struct {
FuncRegex string
}
type AddrLocationSpec struct {
AddrExpr string
}
type OffsetLocationSpec struct {
Offset int
}
type LineLocationSpec struct {
Line int
}
type FuncLocationSpec struct {
PackageName string
AbsolutePackage bool
ReceiverName string
PackageOrReceiverName string
BaseName string
}
func parseLocationSpec(locStr string) (LocationSpec, error) {
rest := locStr
malformed := func(reason string) error {
return fmt.Errorf("Malformed breakpoint location \"%s\" at %d: %s", locStr, len(locStr)-len(rest), reason)
}
if len(rest) <= 0 {
return nil, malformed("empty string")
}
switch rest[0] {
case '+', '-':
offset, err := strconv.Atoi(rest)
if err != nil {
return nil, malformed(err.Error())
}
return &OffsetLocationSpec{offset}, nil
case '/':
if rest[len(rest)-1] == '/' {
rx, rest := readRegex(rest[1:])
if len(rest) < 0 {
return nil, malformed("non-terminated regular expression")
}
if len(rest) > 1 {
return nil, malformed("no line offset can be specified for regular expression locations")
}
return &RegexLocationSpec{rx}, nil
} else {
return parseLocationSpecDefault(locStr, rest)
}
case '*':
return &AddrLocationSpec{rest[1:]}, nil
default:
return parseLocationSpecDefault(locStr, rest)
}
}
func parseLocationSpecDefault(locStr, rest string) (LocationSpec, error) {
malformed := func(reason string) error {
return fmt.Errorf("Malformed breakpoint location \"%s\" at %d: %s", locStr, len(locStr)-len(rest), reason)
}
v := strings.Split(rest, ":")
if len(v) > 2 {
// On Windows, path may contain ":", so split only on last ":"
v = []string{strings.Join(v[0:len(v)-1], ":"), v[len(v)-1]}
}
if len(v) == 1 {
n, err := strconv.ParseInt(v[0], 0, 64)
if err == nil {
return &LineLocationSpec{int(n)}, nil
}
}
spec := &NormalLocationSpec{}
spec.Base = v[0]
spec.FuncBase = parseFuncLocationSpec(spec.Base)
if len(v) < 2 {
spec.LineOffset = -1
return spec, nil
}
rest = v[1]
var err error
spec.LineOffset, err = strconv.Atoi(rest)
if err != nil || spec.LineOffset < 0 {
return nil, malformed("line offset negative or not a number")
}
return spec, nil
}
func readRegex(in string) (rx string, rest string) {
out := make([]rune, 0, len(in))
escaped := false
for i, ch := range in {
if escaped {
if ch == '/' {
out = append(out, '/')
} else {
out = append(out, '\\')
out = append(out, ch)
}
escaped = false
} else {
switch ch {
case '\\':
escaped = true
case '/':
return string(out), in[i:]
default:
out = append(out, ch)
}
}
}
return string(out), ""
}
func parseFuncLocationSpec(in string) *FuncLocationSpec {
var v []string
pathend := strings.LastIndex(in, "/")
if pathend < 0 {
v = strings.Split(in, ".")
} else {
v = strings.Split(in[pathend:], ".")
if len(v) > 0 {
v[0] = in[:pathend] + v[0]
}
}
var spec FuncLocationSpec
switch len(v) {
case 1:
spec.BaseName = v[0]
case 2:
spec.BaseName = v[1]
r := stripReceiverDecoration(v[0])
if r != v[0] {
spec.ReceiverName = r
} else if strings.Index(r, "/") >= 0 {
spec.PackageName = r
} else {
spec.PackageOrReceiverName = r
}
case 3:
spec.BaseName = v[2]
spec.ReceiverName = stripReceiverDecoration(v[1])
spec.PackageName = v[0]
default:
return nil
}
if strings.HasPrefix(spec.PackageName, "/") {
spec.PackageName = spec.PackageName[1:]
spec.AbsolutePackage = true
}
if strings.Index(spec.BaseName, "/") >= 0 || strings.Index(spec.ReceiverName, "/") >= 0 {
return nil
}
return &spec
}
func stripReceiverDecoration(in string) string {
if len(in) < 3 {
return in
}
if (in[0] != '(') || (in[1] != '*') || (in[len(in)-1] != ')') {
return in
}
return in[2 : len(in)-1]
}
func (spec *FuncLocationSpec) Match(sym *gosym.Sym) bool {
if spec.BaseName != sym.BaseName() {
return false
}
recv := stripReceiverDecoration(sym.ReceiverName())
if spec.ReceiverName != "" && spec.ReceiverName != recv {
return false
}
if spec.PackageName != "" {
if spec.AbsolutePackage {
if spec.PackageName != sym.PackageName() {
return false
}
} else {
if !partialPathMatch(spec.PackageName, sym.PackageName()) {
return false
}
}
}
if spec.PackageOrReceiverName != "" && !partialPathMatch(spec.PackageOrReceiverName, sym.PackageName()) && spec.PackageOrReceiverName != recv {
return false
}
return true
}
func (loc *RegexLocationSpec) Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error) {
funcs := d.process.Funcs()
matches, err := regexFilterFuncs(loc.FuncRegex, funcs)
if err != nil {
return nil, err
}
r := make([]api.Location, 0, len(matches))
for i := range matches {
addr, err := d.process.FindFunctionLocation(matches[i], true, 0)
if err == nil {
r = append(r, api.Location{PC: addr})
}
}
return r, nil
}
func (loc *AddrLocationSpec) Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error) {
if scope == nil {
addr, err := strconv.ParseInt(loc.AddrExpr, 0, 64)
if err != nil {
return nil, fmt.Errorf("could not determine current location (scope is nil)")
}
return []api.Location{{PC: uint64(addr)}}, nil
} else {
v, err := scope.EvalExpression(loc.AddrExpr, proc.LoadConfig{true, 0, 0, 0, 0})
if err != nil {
return nil, err
}
if v.Unreadable != nil {
return nil, v.Unreadable
}
switch v.Kind {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
addr, _ := constant.Uint64Val(v.Value)
return []api.Location{{PC: addr}}, nil
case reflect.Func:
_, _, fn := d.process.PCToLine(uint64(v.Base))
pc, err := d.process.FirstPCAfterPrologue(fn, false)
if err != nil {
return nil, err
}
return []api.Location{{PC: uint64(pc)}}, nil
default:
return nil, fmt.Errorf("wrong expression kind: %v", v.Kind)
}
}
}
func (loc *NormalLocationSpec) FileMatch(path string) bool {
return partialPathMatch(loc.Base, path)
}
func partialPathMatch(expr, path string) bool {
if runtime.GOOS == "windows" {
// Accept `expr` which is case-insensitive and slash-insensitive match to `path`
expr = strings.ToLower(filepath.ToSlash(expr))
path = strings.ToLower(filepath.ToSlash(path))
}
if len(expr) < len(path)-1 {
return strings.HasSuffix(path, expr) && (path[len(path)-len(expr)-1] == '/')
} else {
return expr == path
}
}
type AmbiguousLocationError struct {
Location string
CandidatesString []string
CandidatesLocation []api.Location
}
func (ale AmbiguousLocationError) Error() string {
var candidates []string
if ale.CandidatesLocation != nil {
for i := range ale.CandidatesLocation {
candidates = append(candidates, ale.CandidatesLocation[i].Function.Name)
}
} else {
candidates = ale.CandidatesString
}
return fmt.Sprintf("Location \"%s\" ambiguous: %s…", ale.Location, strings.Join(candidates, ", "))
}
func (loc *NormalLocationSpec) Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error) {
funcs := d.process.Funcs()
files := d.process.Sources()
candidates := []string{}
for file := range files {
if loc.FileMatch(file) {
candidates = append(candidates, file)
if len(candidates) >= maxFindLocationCandidates {
break
}
}
}
if loc.FuncBase != nil {
for _, f := range funcs {
if f.Sym == nil {
continue
}
if loc.FuncBase.Match(f.Sym) {
if loc.Base == f.Name {
// if an exact match for the function name is found use it
candidates = []string{f.Name}
break
}
if len(candidates) < maxFindLocationCandidates {
candidates = append(candidates, f.Name)
}
}
}
}
switch len(candidates) {
case 1:
var addr uint64
var err error
if filepath.IsAbs(candidates[0]) {
if loc.LineOffset < 0 {
return nil, fmt.Errorf("Malformed breakpoint location, no line offset specified")
}
addr, err = d.process.FindFileLocation(candidates[0], loc.LineOffset)
} else {
if loc.LineOffset < 0 {
addr, err = d.process.FindFunctionLocation(candidates[0], true, 0)
} else {
addr, err = d.process.FindFunctionLocation(candidates[0], false, loc.LineOffset)
}
}
if err != nil {
return nil, err
}
return []api.Location{{PC: addr}}, nil
case 0:
return nil, fmt.Errorf("Location \"%s\" not found", locStr)
default:
return nil, AmbiguousLocationError{Location: locStr, CandidatesString: candidates}
}
}
func (loc *OffsetLocationSpec) Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error) {
if scope == nil {
return nil, fmt.Errorf("could not determine current location (scope is nil)")
}
file, line, fn := d.process.PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addr, err := d.process.FindFileLocation(file, line+loc.Offset)
return []api.Location{{PC: addr}}, err
}
func (loc *LineLocationSpec) Find(d *Debugger, scope *proc.EvalScope, locStr string) ([]api.Location, error) {
if scope == nil {
return nil, fmt.Errorf("could not determine current location (scope is nil)")
}
file, _, fn := d.process.PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addr, err := d.process.FindFileLocation(file, loc.Line)
return []api.Location{{PC: addr}}, err
}