Files
delve/service/api/prettyprint.go
chainhelen b09aed17fd pkg,service: Optimized the display of examinemem command. (#1888)
1. Don't use intelligent '#' in fmt of go because it is not always satisfying
for diffrent version of golang. Always keep one leading zero for octal and
one leading '0x' for hex manually. Then keep alignment for every byte.

2. Always keep addr alignment when the lens of two adjacent address are
different.

Update #1814.
2020-02-26 22:53:09 -08:00

411 lines
9.5 KiB
Go

package api
import (
"bytes"
"fmt"
"io"
"reflect"
"strconv"
"strings"
)
const (
// strings longer than this will cause slices, arrays and structs to be printed on multiple lines when newlines is enabled
maxShortStringLen = 7
// string used for one indentation level (when printing on multiple lines)
indentString = "\t"
)
// SinglelineString returns a representation of v on a single line.
func (v *Variable) SinglelineString() string {
var buf bytes.Buffer
v.writeTo(&buf, true, false, true, "")
return buf.String()
}
// MultilineString returns a representation of v on multiple lines.
func (v *Variable) MultilineString(indent string) string {
var buf bytes.Buffer
v.writeTo(&buf, true, true, true, indent)
return buf.String()
}
func (v *Variable) writeTo(buf io.Writer, top, newlines, includeType bool, indent string) {
if v.Unreadable != "" {
fmt.Fprintf(buf, "(unreadable %s)", v.Unreadable)
return
}
if !top && v.Addr == 0 && v.Value == "" {
if includeType && v.Type != "void" {
fmt.Fprintf(buf, "%s nil", v.Type)
} else {
fmt.Fprint(buf, "nil")
}
return
}
switch v.Kind {
case reflect.Slice:
v.writeSliceTo(buf, newlines, includeType, indent)
case reflect.Array:
v.writeArrayTo(buf, newlines, includeType, indent)
case reflect.Ptr:
if v.Type == "" || len(v.Children) == 0 {
fmt.Fprint(buf, "nil")
} else if v.Children[0].OnlyAddr && v.Children[0].Addr != 0 {
if strings.Contains(v.Type, "/") {
fmt.Fprintf(buf, "(%q)(%#x)", v.Type, v.Children[0].Addr)
} else {
fmt.Fprintf(buf, "(%s)(%#x)", v.Type, v.Children[0].Addr)
}
} else {
fmt.Fprint(buf, "*")
v.Children[0].writeTo(buf, false, newlines, includeType, indent)
}
case reflect.UnsafePointer:
if len(v.Children) == 0 {
fmt.Fprintf(buf, "unsafe.Pointer(nil)")
} else {
fmt.Fprintf(buf, "unsafe.Pointer(%#x)", v.Children[0].Addr)
}
case reflect.String:
v.writeStringTo(buf)
case reflect.Chan:
if newlines {
v.writeStructTo(buf, newlines, includeType, indent)
} else {
if len(v.Children) == 0 {
fmt.Fprintf(buf, "%s nil", v.Type)
} else {
fmt.Fprintf(buf, "%s %s/%s", v.Type, v.Children[0].Value, v.Children[1].Value)
}
}
case reflect.Struct:
v.writeStructTo(buf, newlines, includeType, indent)
case reflect.Interface:
if v.Addr == 0 {
// an escaped interface variable that points to nil, this shouldn't
// happen in normal code but can happen if the variable is out of scope.
fmt.Fprintf(buf, "nil")
return
}
if includeType {
if v.Children[0].Kind == reflect.Invalid {
fmt.Fprintf(buf, "%s ", v.Type)
if v.Children[0].Addr == 0 {
fmt.Fprint(buf, "nil")
return
}
} else {
fmt.Fprintf(buf, "%s(%s) ", v.Type, v.Children[0].Type)
}
}
data := v.Children[0]
if data.Kind == reflect.Ptr {
if len(data.Children) == 0 {
fmt.Fprint(buf, "...")
} else if data.Children[0].Addr == 0 {
fmt.Fprint(buf, "nil")
} else if data.Children[0].OnlyAddr {
fmt.Fprintf(buf, "0x%x", v.Children[0].Addr)
} else {
v.Children[0].writeTo(buf, false, newlines, !includeType, indent)
}
} else if data.OnlyAddr {
if strings.Contains(v.Type, "/") {
fmt.Fprintf(buf, "*(*%q)(%#x)", v.Type, v.Addr)
} else {
fmt.Fprintf(buf, "*(*%s)(%#x)", v.Type, v.Addr)
}
} else {
v.Children[0].writeTo(buf, false, newlines, !includeType, indent)
}
case reflect.Map:
v.writeMapTo(buf, newlines, includeType, indent)
case reflect.Func:
if v.Value == "" {
fmt.Fprint(buf, "nil")
} else {
fmt.Fprintf(buf, "%s", v.Value)
}
case reflect.Complex64, reflect.Complex128:
fmt.Fprintf(buf, "(%s + %si)", v.Children[0].Value, v.Children[1].Value)
default:
if v.Value != "" {
buf.Write([]byte(v.Value))
} else {
fmt.Fprintf(buf, "(unknown %s)", v.Kind)
}
}
}
func (v *Variable) writeStringTo(buf io.Writer) {
s := v.Value
if len(s) != int(v.Len) {
s = fmt.Sprintf("%s...+%d more", s, int(v.Len)-len(s))
}
fmt.Fprintf(buf, "%q", s)
}
func (v *Variable) writeSliceTo(buf io.Writer, newlines, includeType bool, indent string) {
if includeType {
fmt.Fprintf(buf, "%s len: %d, cap: %d, ", v.Type, v.Len, v.Cap)
}
if v.Base == 0 && len(v.Children) == 0 {
fmt.Fprintf(buf, "nil")
return
}
v.writeSliceOrArrayTo(buf, newlines, indent)
}
func (v *Variable) writeArrayTo(buf io.Writer, newlines, includeType bool, indent string) {
if includeType {
fmt.Fprintf(buf, "%s ", v.Type)
}
v.writeSliceOrArrayTo(buf, newlines, indent)
}
func (v *Variable) writeStructTo(buf io.Writer, newlines, includeType bool, indent string) {
if int(v.Len) != len(v.Children) && len(v.Children) == 0 {
if strings.Contains(v.Type, "/") {
fmt.Fprintf(buf, "(*%q)(%#x)", v.Type, v.Addr)
} else {
fmt.Fprintf(buf, "(*%s)(%#x)", v.Type, v.Addr)
}
return
}
if includeType {
fmt.Fprintf(buf, "%s ", v.Type)
}
nl := v.shouldNewlineStruct(newlines)
fmt.Fprint(buf, "{")
for i := range v.Children {
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
}
fmt.Fprintf(buf, "%s: ", v.Children[i].Name)
v.Children[i].writeTo(buf, false, nl, true, indent+indentString)
if i != len(v.Children)-1 || nl {
fmt.Fprint(buf, ",")
if !nl {
fmt.Fprint(buf, " ")
}
}
}
if len(v.Children) != int(v.Len) {
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
} else {
fmt.Fprint(buf, ",")
}
fmt.Fprintf(buf, "...+%d more", int(v.Len)-len(v.Children))
}
fmt.Fprint(buf, "}")
}
func (v *Variable) writeMapTo(buf io.Writer, newlines, includeType bool, indent string) {
if includeType {
fmt.Fprintf(buf, "%s ", v.Type)
}
if v.Base == 0 && len(v.Children) == 0 {
fmt.Fprintf(buf, "nil")
return
}
nl := newlines && (len(v.Children) > 0)
fmt.Fprint(buf, "[")
for i := 0; i < len(v.Children); i += 2 {
key := &v.Children[i]
value := &v.Children[i+1]
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
}
key.writeTo(buf, false, false, false, indent+indentString)
fmt.Fprint(buf, ": ")
value.writeTo(buf, false, nl, false, indent+indentString)
if i != len(v.Children)-1 || nl {
fmt.Fprint(buf, ", ")
}
}
if len(v.Children)/2 != int(v.Len) {
if len(v.Children) != 0 {
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
} else {
fmt.Fprint(buf, ",")
}
fmt.Fprintf(buf, "...+%d more", int(v.Len)-(len(v.Children)/2))
} else {
fmt.Fprint(buf, "...")
}
}
if nl {
fmt.Fprintf(buf, "\n%s", indent)
}
fmt.Fprint(buf, "]")
}
func (v *Variable) shouldNewlineArray(newlines bool) bool {
if !newlines || len(v.Children) == 0 {
return false
}
kind, hasptr := (&v.Children[0]).recursiveKind()
switch kind {
case reflect.Slice, reflect.Array, reflect.Struct, reflect.Map, reflect.Interface:
return true
case reflect.String:
if hasptr {
return true
}
for i := range v.Children {
if len(v.Children[i].Value) > maxShortStringLen {
return true
}
}
return false
default:
return false
}
}
func (v *Variable) recursiveKind() (reflect.Kind, bool) {
hasptr := false
var kind reflect.Kind
for {
kind = v.Kind
if kind == reflect.Ptr {
hasptr = true
v = &(v.Children[0])
} else {
break
}
}
return kind, hasptr
}
func (v *Variable) shouldNewlineStruct(newlines bool) bool {
if !newlines || len(v.Children) == 0 {
return false
}
for i := range v.Children {
kind, hasptr := (&v.Children[i]).recursiveKind()
switch kind {
case reflect.Slice, reflect.Array, reflect.Struct, reflect.Map, reflect.Interface:
return true
case reflect.String:
if hasptr {
return true
}
if len(v.Children[i].Value) > maxShortStringLen {
return true
}
}
}
return false
}
func (v *Variable) writeSliceOrArrayTo(buf io.Writer, newlines bool, indent string) {
nl := v.shouldNewlineArray(newlines)
fmt.Fprint(buf, "[")
for i := range v.Children {
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
}
v.Children[i].writeTo(buf, false, nl, false, indent+indentString)
if i != len(v.Children)-1 || nl {
fmt.Fprint(buf, ",")
}
}
if len(v.Children) != int(v.Len) {
if len(v.Children) != 0 {
if nl {
fmt.Fprintf(buf, "\n%s%s", indent, indentString)
} else {
fmt.Fprint(buf, ",")
}
fmt.Fprintf(buf, "...+%d more", int(v.Len)-len(v.Children))
} else {
fmt.Fprint(buf, "...")
}
}
if nl {
fmt.Fprintf(buf, "\n%s", indent)
}
fmt.Fprint(buf, "]")
}
func PrettyExamineMemory(address uintptr, memArea []byte, format byte) string {
var (
cols int
colFormat string
addrLen int
addrFmt string
)
// Diffrent versions of golang output differently about '#'.
// See https://ci.appveyor.com/project/derekparker/delve-facy3/builds/30179356.
switch format {
case 'b':
cols = 4 // Avoid emitting rows that are too long when using binary format
colFormat = "%08b"
case 'o':
cols = 8
colFormat = "%04o" // Always keep one leading zero for octal.
case 'd':
cols = 8
colFormat = "%03d"
case 'x':
cols = 8
colFormat = "0x%02x" // Always keep one leading '0x' for hex.
default:
return fmt.Sprintf("not supprted format %q\n", string(format))
}
l := len(memArea)
rows := l / cols
if l%cols != 0 {
rows++
}
// Avoid the lens of two adjacent address are different, so always use the last addr's len to format.
if l != 0 {
addrLen = len(fmt.Sprintf("%x", uint64(address)+uint64(l)))
}
addrFmt = "0x%0" + strconv.Itoa(addrLen) + "x:"
lines := ""
for i := 0; i < rows; i++ {
lines += fmt.Sprintf(addrFmt, address)
for j := 0; j < cols && i*cols+j < l; j++ {
curOutput := " " + fmt.Sprintf(colFormat, memArea[i*cols+j])
lines += curOutput
}
lines += "\n"
address += uintptr(cols)
}
return lines
}