/
locations.go
567 lines (501 loc) · 15.9 KB
/
locations.go
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package locspec
import (
"fmt"
"go/constant"
"path"
"path/filepath"
"reflect"
"regexp"
"runtime"
"strconv"
"strings"
"github.com/undoio/delve/pkg/proc"
"github.com/undoio/delve/service/api"
)
const maxFindLocationCandidates = 5
// LocationSpec is an interface that represents a parsed location spec string.
type LocationSpec interface {
// Find returns all locations that match the location spec.
Find(t *proc.Target, processArgs []string, scope *proc.EvalScope, locStr string, includeNonExecutableLines bool, substitutePathRules [][2]string) ([]api.Location, error)
}
// NormalLocationSpec represents a basic location spec.
// This can be a file:line or func:line.
type NormalLocationSpec struct {
Base string
FuncBase *FuncLocationSpec
LineOffset int
}
// RegexLocationSpec represents a regular expression
// location expression such as /^myfunc$/.
type RegexLocationSpec struct {
FuncRegex string
}
// AddrLocationSpec represents an address when used
// as a location spec.
type AddrLocationSpec struct {
AddrExpr string
}
// OffsetLocationSpec represents a location spec that
// is an offset of the current location (file:line).
type OffsetLocationSpec struct {
Offset int
}
// LineLocationSpec represents a line number in the current file.
type LineLocationSpec struct {
Line int
}
// FuncLocationSpec represents a function in the target program.
type FuncLocationSpec struct {
PackageName string
AbsolutePackage bool
ReceiverName string
PackageOrReceiverName string
BaseName string
}
// Parse will turn locStr into a parsed LocationSpec.
func Parse(locStr string) (LocationSpec, error) {
rest := locStr
malformed := func(reason string) error {
//lint:ignore ST1005 backwards compatibility
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{AddrExpr: rest[1:]}, nil
default:
return parseLocationSpecDefault(locStr, rest)
}
}
func parseLocationSpecDefault(locStr, rest string) (LocationSpec, error) {
malformed := func(reason string) error {
//lint:ignore ST1005 backwards compatibility
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, '\\', 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]
}
// Match will return whether the provided function matches the location spec.
func (spec *FuncLocationSpec) Match(sym *proc.Function, packageMap map[string][]string) 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 !packageMatch(spec.PackageName, sym.PackageName(), packageMap) {
return false
}
}
}
if spec.PackageOrReceiverName != "" && !packageMatch(spec.PackageOrReceiverName, sym.PackageName(), packageMap) && spec.PackageOrReceiverName != recv {
return false
}
return true
}
func packageMatch(specPkg, symPkg string, packageMap map[string][]string) bool {
for _, pkg := range packageMap[specPkg] {
if partialPackageMatch(pkg, symPkg) {
return true
}
}
return partialPackageMatch(specPkg, symPkg)
}
// Find will search all functions in the target program and filter them via the
// regex location spec. Only functions matching the regex will be returned.
func (loc *RegexLocationSpec) Find(t *proc.Target, _ []string, scope *proc.EvalScope, locStr string, includeNonExecutableLines bool, _ [][2]string) ([]api.Location, error) {
funcs := scope.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 {
addrs, _ := proc.FindFunctionLocation(t, matches[i], 0)
if len(addrs) > 0 {
r = append(r, addressesToLocation(addrs))
}
}
return r, nil
}
// Find returns the locations specified via the address location spec.
func (loc *AddrLocationSpec) Find(t *proc.Target, _ []string, scope *proc.EvalScope, locStr string, includeNonExecutableLines bool, _ [][2]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
}
v, err := scope.EvalExpression(loc.AddrExpr, proc.LoadConfig{FollowPointers: true})
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 := scope.BinInfo.PCToFunc(uint64(v.Base))
pc, err := proc.FirstPCAfterPrologue(t, fn, false)
if err != nil {
return nil, err
}
return []api.Location{{PC: pc}}, nil
default:
return nil, fmt.Errorf("wrong expression kind: %v", v.Kind)
}
}
// FileMatch is true if the path matches the location spec.
func (loc *NormalLocationSpec) FileMatch(path string) bool {
return partialPathMatch(loc.Base, path)
}
func tryMatchRelativePathByProc(expr, debugname, file string) bool {
return len(expr) > 0 && expr[0] == '.' && file == path.Join(path.Dir(debugname), expr)
}
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))
}
return partialPackageMatch(expr, path)
}
func partialPackageMatch(expr, path string) bool {
if len(expr) < len(path)-1 {
return strings.HasSuffix(path, expr) && (path[len(path)-len(expr)-1] == '/')
}
return expr == path
}
// AmbiguousLocationError is returned when the location spec
// should only return one location but returns multiple instead.
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, ", "))
}
// Find will return a list of locations that match the given location spec.
// This matches each other location spec that does not already have its own spec
// implemented (such as regex, or addr).
func (loc *NormalLocationSpec) Find(t *proc.Target, processArgs []string, scope *proc.EvalScope, locStr string, includeNonExecutableLines bool, substitutePathRules [][2]string) ([]api.Location, error) {
limit := maxFindLocationCandidates
var candidateFiles []string
for _, sourceFile := range scope.BinInfo.Sources {
substFile := sourceFile
if len(substitutePathRules) > 0 {
substFile = SubstitutePath(sourceFile, substitutePathRules)
}
if loc.FileMatch(substFile) || (len(processArgs) >= 1 && tryMatchRelativePathByProc(loc.Base, processArgs[0], substFile)) {
candidateFiles = append(candidateFiles, sourceFile)
if len(candidateFiles) >= limit {
break
}
}
}
limit -= len(candidateFiles)
var candidateFuncs []string
if loc.FuncBase != nil && limit > 0 {
candidateFuncs = loc.findFuncCandidates(scope, limit)
}
if matching := len(candidateFiles) + len(candidateFuncs); matching == 0 {
// if no result was found this locations string could be an
// expression that the user forgot to prefix with '*', try treating it as
// such.
addrSpec := &AddrLocationSpec{AddrExpr: locStr}
locs, err := addrSpec.Find(t, processArgs, scope, locStr, includeNonExecutableLines, nil)
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 addrs []uint64
var err error
if len(candidateFiles) == 1 {
if loc.LineOffset < 0 {
//lint:ignore ST1005 backwards compatibility
return nil, fmt.Errorf("Malformed breakpoint location, no line offset specified")
}
addrs, err = proc.FindFileLocation(t, candidateFiles[0], loc.LineOffset)
if includeNonExecutableLines {
if _, isCouldNotFindLine := err.(*proc.ErrCouldNotFindLine); isCouldNotFindLine {
return []api.Location{{File: candidateFiles[0], Line: loc.LineOffset}}, nil
}
}
} else { // len(candidateFuncs) == 1
addrs, err = proc.FindFunctionLocation(t, candidateFuncs[0], loc.LineOffset)
}
if err != nil {
return nil, err
}
return []api.Location{addressesToLocation(addrs)}, nil
}
func (loc *NormalLocationSpec) findFuncCandidates(scope *proc.EvalScope, limit int) []string {
candidateFuncs := map[string]struct{}{}
// See if it matches generic functions first
for fname := range scope.BinInfo.LookupGenericFunc() {
if len(candidateFuncs) >= limit {
break
}
if !loc.FuncBase.Match(&proc.Function{Name: fname}, scope.BinInfo.PackageMap) {
continue
}
if loc.Base == fname {
return []string{fname}
}
candidateFuncs[fname] = struct{}{}
}
for _, f := range scope.BinInfo.LookupFunc {
if len(candidateFuncs) >= limit {
break
}
if !loc.FuncBase.Match(f, scope.BinInfo.PackageMap) {
continue
}
if loc.Base == f.Name {
// if an exact match for the function name is found use it
return []string{f.Name}
}
// If f is an instantiation of a generic function see if we should add its generic version instead.
if gn := f.NameWithoutTypeParams(); gn != "" {
if _, alreadyAdded := candidateFuncs[gn]; !alreadyAdded {
candidateFuncs[f.Name] = struct{}{}
}
} else {
candidateFuncs[f.Name] = struct{}{}
}
}
// convert candidateFuncs map into an array of its keys
r := make([]string, 0, len(candidateFuncs))
for s := range candidateFuncs {
r = append(r, s)
}
return r
}
func crossPlatformPath(path string) string {
if runtime.GOOS == "windows" {
return strings.ToLower(path)
}
return path
}
// SubstitutePath applies the specified path substitution rules to path.
func SubstitutePath(path string, rules [][2]string) string {
path = crossPlatformPath(path)
// On windows paths returned from headless server are as c:/dir/dir
// though os.PathSeparator is '\\'
separator := "/" //make it default
if strings.Contains(path, "\\") { //dependent on the path
separator = "\\"
}
for _, r := range rules {
from := crossPlatformPath(r[0])
to := r[1]
if !strings.HasSuffix(from, separator) {
from = from + separator
}
if !strings.HasSuffix(to, separator) {
to = to + separator
}
if strings.HasPrefix(path, from) {
return strings.Replace(path, from, to, 1)
}
}
return path
}
func addressesToLocation(addrs []uint64) api.Location {
if len(addrs) <= 0 {
return api.Location{}
}
return api.Location{PC: addrs[0], PCs: addrs}
}
// Find returns the location after adding the offset amount to the current line number.
func (loc *OffsetLocationSpec) Find(t *proc.Target, _ []string, scope *proc.EvalScope, _ string, includeNonExecutableLines bool, _ [][2]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 := scope.BinInfo.PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addrs, err := proc.FindFileLocation(t, file, line+loc.Offset)
if includeNonExecutableLines {
if _, isCouldNotFindLine := err.(*proc.ErrCouldNotFindLine); isCouldNotFindLine {
return []api.Location{{File: file, Line: line + loc.Offset}}, nil
}
}
return []api.Location{addressesToLocation(addrs)}, err
}
// Find will return the location at the given line in the current file.
func (loc *LineLocationSpec) Find(t *proc.Target, _ []string, scope *proc.EvalScope, _ string, includeNonExecutableLines bool, _ [][2]string) ([]api.Location, error) {
if scope == nil {
return nil, fmt.Errorf("could not determine current location (scope is nil)")
}
file, _, fn := scope.BinInfo.PCToLine(scope.PC)
if fn == nil {
return nil, fmt.Errorf("could not determine current location")
}
addrs, err := proc.FindFileLocation(t, file, loc.Line)
if includeNonExecutableLines {
if _, isCouldNotFindLine := err.(*proc.ErrCouldNotFindLine); isCouldNotFindLine {
return []api.Location{{File: file, Line: loc.Line}}, nil
}
}
return []api.Location{addressesToLocation(addrs)}, err
}
func regexFilterFuncs(filter string, allFuncs []proc.Function) ([]string, error) {
regex, err := regexp.Compile(filter)
if err != nil {
return nil, fmt.Errorf("invalid filter argument: %s", err.Error())
}
funcs := []string{}
for _, f := range allFuncs {
if regex.MatchString(f.Name) {
funcs = append(funcs, f.Name)
}
}
return funcs, nil
}