delve/service/debugger/locations.go
aarzilli 8f1fc63da8 proc,service,terminal: read defer list
Adds -defer flag to the stack command that decorates the stack traces
by associating each stack frame with its deferred calls.

Reworks proc.next to use this feature instead of using proc.DeferPC,
laying the groundwork to implement #1240.
2018-07-24 14:58:56 -07:00

422 lines
10 KiB
Go

package debugger
import (
"fmt"
"go/constant"
"path/filepath"
"reflect"
"runtime"
"strconv"
"strings"
"github.com/derekparker/delve/pkg/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.Contains(r, "/") {
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.Contains(spec.BaseName, "/") || strings.Contains(spec.ReceiverName, "/") {
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 proc.Function) 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.target.BinInfo().Functions
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 := proc.FindFunctionLocation(d.target, 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.target.BinInfo().PCToLine(uint64(v.Base))
pc, err := proc.FirstPCAfterPrologue(d.target, 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) {
limit := maxFindLocationCandidates
var candidateFiles []string
for _, file := range d.target.BinInfo().Sources {
if loc.FileMatch(file) {
candidateFiles = append(candidateFiles, file)
if len(candidateFiles) >= limit {
break
}
}
}
limit -= len(candidateFiles)
var candidateFuncs []string
if loc.FuncBase != nil {
for _, f := range d.target.BinInfo().Functions {
if !loc.FuncBase.Match(f) {
continue
}
if loc.Base == f.Name {
// if an exact match for the function name is found use it
candidateFuncs = []string{f.Name}
break
}
candidateFuncs = append(candidateFuncs, f.Name)
if len(candidateFuncs) >= limit {
break
}
}
}
if matching := len(candidateFiles) + len(candidateFuncs); matching == 0 {
// if no result was found treat this locations string could be an
// expression that the user forgot to prefix with '*', try treating it as
// such.
addrSpec := &AddrLocationSpec{locStr}
locs, err := addrSpec.Find(d, scope, locStr)
if err != nil {
return nil, fmt.Errorf("Location \"%s\" not found", locStr)
}
return locs, nil
} else if matching > 1 {
return nil, AmbiguousLocationError{Location: locStr, CandidatesString: append(candidateFiles, candidateFuncs...)}
}
// len(candidateFiles) + len(candidateFuncs) == 1
var addr uint64
var err error
if len(candidateFiles) == 1 {
if loc.LineOffset < 0 {
return nil, fmt.Errorf("Malformed breakpoint location, no line offset specified")
}
addr, err = proc.FindFileLocation(d.target, candidateFiles[0], loc.LineOffset)
} else { // len(candidateFUncs) == 1
if loc.LineOffset < 0 {
addr, err = proc.FindFunctionLocation(d.target, candidateFuncs[0], true, 0)
} else {
addr, err = proc.FindFunctionLocation(d.target, candidateFuncs[0], false, loc.LineOffset)
}
}
if err != nil {
return nil, err
}
return []api.Location{{PC: addr}}, nil
}
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)")
}
if loc.Offset == 0 {
return []api.Location{{PC: scope.PC}}, nil
}
file, line, fn := d.target.BinInfo().PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addr, err := proc.FindFileLocation(d.target, 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.target.BinInfo().PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addr, err := proc.FindFileLocation(d.target, file, loc.Line)
return []api.Location{{PC: addr}}, err
}