fix --detail error

Author: corbamico

README.md

@@ -18,13 +18,15 @@ Usage:
 
 Available Commands:
   decode      encode a string into ascii85(re-map), which tbc file used
-  disassemble disassemble a .tbc file, which can be on disk/url
+  decompile   disassemble a .tbc file, which can be on disk/url
   encode      A brief description of your command
 
 Example:
     tbcload encode 123456
-    tbcload disassemble test.tbc  #disassemble a file named test.tbc
-    tbcload disassemble http://127.0.0.1/test.tcl #disassemble from a url
+    tbcload encode  --hex "00010203"
+    tbcload decompile test.tbc  #disassemble a file named test.tbc
+    tbcload decompile --detail test.tbc
+    tbcload decompile http://127.0.0.1/test.tcl #disassemble from a url
 
     example url, can be found as https://github.com/ActiveState/teapot/raw/master/lib/tbcload/tests/tbc10/proc.tbc
 ```

encoding.go

@@ -37,10 +37,14 @@ func Encode(dst, src []byte) int {
 
 	//step 5 map special char
 	for index := 0; index < encodeLen; index++ {
-		dst[index] = encodeMap[dst[index]-'!']
+		//there is 'z'(122) special for 0x00000000
+		if n := int(dst[index] - '!'); n < len(encodeMap) {
+			dst[index] = encodeMap[n]
+		}
 	}
-
-	return encodeLen - (len(srcCopy) - len(src))
+	//if 0x00 00 00 00->'z', we cannot known how many '!' drop
+	return encodeLen
+	//return encodeLen - (len(srcCopy) - len(src))
 }
 
 /*
@@ -61,10 +65,12 @@ func Decode(dst, src []byte) (ndst int) {
 		srcCopy[index] = decodeMap[src[index]] + '!'
 	}
 
-	//step 1 align to 5 bytes,padding as 0
+	//step 1 align to 5 bytes,padding as 0 (but not for z)
+	//no need do this
+	//BUGBUG, if there is 'z' in middle
 	srcCopy = align5Bytes(srcCopy, '!')
 
-	//step 2 Big-Endian to Little-Endian
+	//step 2 Big-Endian to Little-Endian(but not for 'z')
 	exchangeEvery5(srcCopy)
 
 	//step 3 ascii85 decode
@@ -241,7 +247,11 @@ func align4Bytes(src []byte, padding byte) []byte {
 }
 
 func align5Bytes(src []byte, padding byte) []byte {
-	switch len(src) % 5 {
+	//'z' dont need align to 5 bytes
+	numZ := bytes.Count(src, []byte{'z'})
+	nLen := len(src) - numZ
+
+	switch nLen % 5 {
 	case 1:
 		src = append(src, padding)
 		fallthrough
@@ -272,14 +282,18 @@ func exchangeEvery4(src []byte) {
 	}
 }
 func exchangeEvery5(src []byte) {
-	if len(src)%5 != 0 {
-		return
-	}
-
+	//special 'z' for 0x00000000, dont exchange 'z'
 	for len(src) > 0 {
-		src[0], src[1], src[3], src[4] = src[4], src[3], src[1], src[0]
-		src = src[5:]
+		if src[0] == 'z' {
+			src = src[1:]
+		} else if len(src) >= 5 {
+			src[0], src[1], src[3], src[4] = src[4], src[3], src[1], src[0]
+			src = src[5:]
+		} else {
+			return
+		}
 	}
+	return
 }
 
 var encodeMap = [...]byte{
@@ -497,7 +511,8 @@ var decodeMap = [...]byte{
 	3,              /* w (replaces $) */
 	58,             /* x (replaces [) */
 	59,             /* y (replaces \) */
-	a85Z,           /* z */
+	89,             /* z->z,special for 0x00000000 */
+	//	a85Z,       /* z */
 	a85IllegalChar, /* { */
 	60,             /* | (replaces ]) */
 	a85IllegalChar, /* } */

encoding_test.go

@@ -84,7 +84,8 @@ func ExampleChainReader2() {
 	// 345
 }
 func ExampleEncode() {
-	src := []byte("testing aliases for non-existent targets")
+	//src := []byte("testing aliases for non-existent targets")
+	src := []byte{0, 0, 0, 0}
 	dst := make([]byte, 280)
 	length := Encode(dst, src)
 	fmt.Printf("%s", dst[:length])
@@ -93,7 +94,8 @@ func ExampleEncode() {
 }
 
 func ExampleDecode() {
-	src := []byte("4;,>!?.EH&ih-(!e2xi6zyiE<!22>:v35>:v22Ppv2j:U!*|yTv0#>6#5cSs!)'!!")
+	src := []byte("4;,>!?.EH&ih-(!e2xi6zyiE<!22>:v35>:v22Ppv2j:U!*|yTv0#>6#5cSs!)'!")
+	//src := []byte("z")
 	dst := make([]byte, 280)
 	length := Decode(dst, src)
 	fmt.Printf("%s", string(dst[:length]))

parser.go

@@ -8,19 +8,21 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"os"
 	"strconv"
 	"strings"
 )
 
 //Parser read tbc file and write 'dissemble' to w
 type Parser struct {
-	r          Decoder
-	w          bufio.Writer
-	Detail     bool //true: disassemble bytecode
-	codeBytes  []byte
-	codeDelta  []byte
-	codeLength []byte
+	r      Decoder
+	w      bufio.Writer
+	Detail bool //true: disassemble bytecode
+
+	codeBytes  bytes.Buffer
+	codeDelta  bytes.Buffer
+	codeLength bytes.Buffer
 }
 
 //NewParser create Parser
@@ -276,58 +278,74 @@ func (p *Parser) parseAuxDataArray() (err error) {
 func (p *Parser) parseCodeDelta() (err error) {
 	var buf [20480]byte
 	var nRead int
-	if _, err = p.parseIntLine(); err != nil {
+	var nRes int64
+	if nRes, err = p.parseIntLine(); err != nil {
 		return
 	}
 	if nRead, err = p.r.Read(buf[:]); err != nil {
 		return
 	}
-	s := hex.EncodeToString(buf[:nRead])
-	_, err = p.w.WriteString(s)
-	err = p.w.WriteByte('\n')
+	p.codeDelta.Reset()
+
+	if nRes > 0 && nRead > 0 {
+		s := hex.EncodeToString(buf[:nRead])
+		_, err = p.w.WriteString(s)
+		err = p.w.WriteByte('\n')
 
-	if nRead > 0 {
-		p.codeDelta = make([]byte, nRead)
-		copy(p.codeDelta, buf[:nRead])
+		if nRead > int(nRes) {
+			nRead = int(nRes)
+		}
+		p.codeDelta.Write(buf[:nRead])
 	}
 	return
 }
 func (p *Parser) parseCodeLength() (err error) {
 	var buf [20480]byte
 	var nRead int
-	if _, err = p.parseIntLine(); err != nil {
+	var nRes int64
+	if nRes, err = p.parseIntLine(); err != nil {
 		return
 	}
 	if nRead, err = p.r.Read(buf[:]); err != nil {
 		return
 	}
-	s := hex.EncodeToString(buf[:nRead])
-	_, err = p.w.WriteString(s)
-	err = p.w.WriteByte('\n')
 
-	if nRead > 0 {
-		p.codeLength = make([]byte, nRead)
-		copy(p.codeLength, buf[:nRead])
+	p.codeLength.Reset()
+
+	if nRes > 0 && nRead > 0 {
+		s := hex.EncodeToString(buf[:nRead])
+		_, err = p.w.WriteString(s)
+		err = p.w.WriteByte('\n')
+
+		if nRead > int(nRes) {
+			nRead = int(nRes)
+		}
+		p.codeLength.Write(buf[:nRead])
 	}
 	return
 }
 
 func (p *Parser) parseCode() (err error) {
 	var buf [20480]byte
 	var nRead int
-	if _, err = p.parseIntLine(); err != nil {
+	var nRes int64
+	if nRes, err = p.parseIntLine(); err != nil {
 		return
 	}
 	if nRead, err = p.r.Read(buf[:]); err != nil {
 		return
 	}
-	s := hex.EncodeToString(buf[:nRead])
-	_, err = p.w.WriteString(s)
-	err = p.w.WriteByte('\n')
+	p.codeBytes.Reset()
 
-	if nRead > 0 {
-		p.codeBytes = make([]byte, nRead)
-		copy(p.codeBytes, buf[:nRead])
+	if nRes > 0 && nRead > 0 {
+		s := hex.EncodeToString(buf[:nRead])
+		_, err = p.w.WriteString(s)
+		err = p.w.WriteByte('\n')
+
+		if nRead > int(nRes) {
+			nRead = int(nRes)
+		}
+		p.codeBytes.Write(buf[:nRead])
 	}
 	return
 }
@@ -424,9 +442,11 @@ func (p *Parser) parseDecompile() (err error) {
 	var str string
 	var bytes int
 	var totalBytes int
-	src := p.codeBytes
+	src := p.codeBytes.Bytes()
+	codeDelta := p.codeDelta.Bytes()
+	codeLength := p.codeLength.Bytes()
 
-	numCmds := len(p.codeDelta)
+	numCmds := len(codeDelta)
 	indexCmds := 0
 	cmdBegin := true
 	var cmdBytes, cmdDelta int
@@ -439,7 +459,8 @@ func (p *Parser) parseDecompile() (err error) {
 			return err
 		}
 		//1. print command title: command %d,pc=xx-xx
-		if numCmds > 0 && indexCmds < (numCmds-1) {
+		if numCmds > 0 && indexCmds < (numCmds) {
+
 			if cmdBegin {
 				cmdBytes = bytes
 				cmdBegin = false
@@ -448,14 +469,23 @@ func (p *Parser) parseDecompile() (err error) {
 
 				for samePCforCmds {
 
-					cmdDelta = int(p.codeDelta[indexCmds+1])
+					//cmdDelta = int(p.codeDelta[indexCmds+1])
+
 					p.w.WriteString(fmt.Sprintf("\tCommand %d", indexCmds))
-					if indexCmds < len(p.codeLength) {
+					if indexCmds < len(codeLength) {
 						//BUG,FIXME, we dont consider codeLength = 0xFF 4bytes case
-						p.w.WriteString(fmt.Sprintf(",pc= %d-%d", totalBytes, totalBytes+int(p.codeLength[indexCmds])-1))
+						p.w.WriteString(fmt.Sprintf(",pc= %d-%d", totalBytes, totalBytes+int(codeLength[indexCmds])-1))
 					}
 					p.w.WriteByte('\n')
+
 					indexCmds++
+					//cmdDelta 是下一条Command 相对于当前Comand的bytes偏移量
+					//如果是最后一条命令，cmdDelta赋值MAX
+					if indexCmds < len(codeDelta) {
+						cmdDelta = int(codeDelta[indexCmds])
+					} else {
+						cmdDelta = math.MaxInt32
+					}
 
 					if cmdDelta != 0 {
 						samePCforCmds = false

parser_test.go

@@ -76,7 +76,7 @@ func TestParser(t *testing.T) {
 
 func TestSingleFile(t *testing.T) {
 	//sFile := "D:\\Program Files (x86)\\TclPro1.4\\win32-ix86\\bin\\simple.tbc"
-	sFile := "d:\\Project\\go\\src\\github.com\\corbamico\\tbcload\\test\\aux1.tbc"
+	sFile := "c:\\Project\\go\\src\\github.com\\corbamico\\tbcload\\test\\aux1.tbc"
 	fs, err := os.Open(sFile)
 	if err != nil {
 		t.Error(err)

tbcload/cmd/decode.go

@@ -35,7 +35,8 @@ For example:
 		var src []byte
 
 		if len(args) == 1 {
-			dst := make([]byte, len(args[0]))
+			//if there is 'z' ,length will large than src
+			dst := make([]byte, len(args[0])*4)
 
 			src = []byte(args[0])
 			if ndst := tbcload.Decode(dst, src); ndst > 0 {