mirror of https://github.com/beego/bee.git
153 lines
4.0 KiB
Go
153 lines
4.0 KiB
Go
package line
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"path/filepath"
|
|
|
|
"github.com/derekparker/delve/pkg/dwarf/util"
|
|
)
|
|
|
|
type DebugLinePrologue struct {
|
|
UnitLength uint32
|
|
Version uint16
|
|
Length uint32
|
|
MinInstrLength uint8
|
|
InitialIsStmt uint8
|
|
LineBase int8
|
|
LineRange uint8
|
|
OpcodeBase uint8
|
|
StdOpLengths []uint8
|
|
}
|
|
|
|
type DebugLineInfo struct {
|
|
Prologue *DebugLinePrologue
|
|
IncludeDirs []string
|
|
FileNames []*FileEntry
|
|
Instructions []byte
|
|
Lookup map[string]*FileEntry
|
|
|
|
Logf func(string, ...interface{})
|
|
|
|
// stateMachineCache[pc] is a state machine stopped at pc
|
|
stateMachineCache map[uint64]*StateMachine
|
|
|
|
// lastMachineCache[pc] is a state machine stopped at an address after pc
|
|
lastMachineCache map[uint64]*StateMachine
|
|
|
|
// staticBase is the address at which the executable is loaded, 0 for non-PIEs
|
|
staticBase uint64
|
|
}
|
|
|
|
type FileEntry struct {
|
|
Path string
|
|
DirIdx uint64
|
|
LastModTime uint64
|
|
Length uint64
|
|
}
|
|
|
|
type DebugLines []*DebugLineInfo
|
|
|
|
// ParseAll parses all debug_line segments found in data
|
|
func ParseAll(data []byte, logfn func(string, ...interface{}), staticBase uint64) DebugLines {
|
|
var (
|
|
lines = make(DebugLines, 0)
|
|
buf = bytes.NewBuffer(data)
|
|
)
|
|
|
|
// We have to parse multiple file name tables here.
|
|
for buf.Len() > 0 {
|
|
lines = append(lines, Parse("", buf, logfn, staticBase))
|
|
}
|
|
|
|
return lines
|
|
}
|
|
|
|
// Parse parses a single debug_line segment from buf. Compdir is the
|
|
// DW_AT_comp_dir attribute of the associated compile unit.
|
|
func Parse(compdir string, buf *bytes.Buffer, logfn func(string, ...interface{}), staticBase uint64) *DebugLineInfo {
|
|
dbl := new(DebugLineInfo)
|
|
dbl.Logf = logfn
|
|
dbl.staticBase = staticBase
|
|
dbl.Lookup = make(map[string]*FileEntry)
|
|
if compdir != "" {
|
|
dbl.IncludeDirs = append(dbl.IncludeDirs, compdir)
|
|
}
|
|
|
|
dbl.stateMachineCache = make(map[uint64]*StateMachine)
|
|
dbl.lastMachineCache = make(map[uint64]*StateMachine)
|
|
|
|
parseDebugLinePrologue(dbl, buf)
|
|
parseIncludeDirs(dbl, buf)
|
|
parseFileEntries(dbl, buf)
|
|
|
|
// Instructions size calculation breakdown:
|
|
// - dbl.Prologue.UnitLength is the length of the entire unit, not including the 4 bytes to represent that length.
|
|
// - dbl.Prologue.Length is the length of the prologue not including unit length, version or prologue length itself.
|
|
// - So you have UnitLength - PrologueLength - (version_length_bytes(2) + prologue_length_bytes(4)).
|
|
dbl.Instructions = buf.Next(int(dbl.Prologue.UnitLength - dbl.Prologue.Length - 6))
|
|
|
|
return dbl
|
|
}
|
|
|
|
func parseDebugLinePrologue(dbl *DebugLineInfo, buf *bytes.Buffer) {
|
|
p := new(DebugLinePrologue)
|
|
|
|
p.UnitLength = binary.LittleEndian.Uint32(buf.Next(4))
|
|
p.Version = binary.LittleEndian.Uint16(buf.Next(2))
|
|
p.Length = binary.LittleEndian.Uint32(buf.Next(4))
|
|
p.MinInstrLength = uint8(buf.Next(1)[0])
|
|
p.InitialIsStmt = uint8(buf.Next(1)[0])
|
|
p.LineBase = int8(buf.Next(1)[0])
|
|
p.LineRange = uint8(buf.Next(1)[0])
|
|
p.OpcodeBase = uint8(buf.Next(1)[0])
|
|
|
|
p.StdOpLengths = make([]uint8, p.OpcodeBase-1)
|
|
binary.Read(buf, binary.LittleEndian, &p.StdOpLengths)
|
|
|
|
dbl.Prologue = p
|
|
}
|
|
|
|
func parseIncludeDirs(info *DebugLineInfo, buf *bytes.Buffer) {
|
|
for {
|
|
str, _ := util.ParseString(buf)
|
|
if str == "" {
|
|
break
|
|
}
|
|
|
|
info.IncludeDirs = append(info.IncludeDirs, str)
|
|
}
|
|
}
|
|
|
|
func parseFileEntries(info *DebugLineInfo, buf *bytes.Buffer) {
|
|
for {
|
|
entry := readFileEntry(info, buf, true)
|
|
if entry.Path == "" {
|
|
break
|
|
}
|
|
|
|
info.FileNames = append(info.FileNames, entry)
|
|
info.Lookup[entry.Path] = entry
|
|
}
|
|
}
|
|
|
|
func readFileEntry(info *DebugLineInfo, buf *bytes.Buffer, exitOnEmptyPath bool) *FileEntry {
|
|
entry := new(FileEntry)
|
|
|
|
entry.Path, _ = util.ParseString(buf)
|
|
if entry.Path == "" && exitOnEmptyPath {
|
|
return entry
|
|
}
|
|
|
|
entry.DirIdx, _ = util.DecodeULEB128(buf)
|
|
entry.LastModTime, _ = util.DecodeULEB128(buf)
|
|
entry.Length, _ = util.DecodeULEB128(buf)
|
|
if !filepath.IsAbs(entry.Path) {
|
|
if entry.DirIdx >= 0 && entry.DirIdx < uint64(len(info.IncludeDirs)) {
|
|
entry.Path = filepath.Join(info.IncludeDirs[entry.DirIdx], entry.Path)
|
|
}
|
|
}
|
|
|
|
return entry
|
|
}
|