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package text
import (
"encoding/binary"
"io"
"jinx/pkg/lang/vm/code"
"jinx/pkg/libs/source"
"math"
"strconv"
"strings"
"unicode"
)
type Compiler struct {
src source.Walker
codePos int
labelPositions map[string]int
labelReferences []labelReference
}
func NewCompiler(src io.Reader) *Compiler {
return &Compiler{
src: *source.NewWalker(src),
codePos: 0,
labelPositions: map[string]int{},
labelReferences: []labelReference{},
}
}
func (cpl *Compiler) Compile() (code.Code, error) {
res := []byte{}
info := code.NewDebugInfo("unknown file")
for {
_, eof, err := cpl.src.Peek()
if err != nil {
return code.Code{}, err
}
if eof {
break
}
line, err := cpl.compileLine()
if err != nil {
return code.Code{}, err
}
cpl.codePos += len(line)
if line != nil {
info.AppendLine(cpl.codePos-1, cpl.src.Loc().Row-1)
}
res = append(res, line...)
}
if err := cpl.linkLabels(res); err != nil {
return code.Code{}, err
}
return code.New(res, info), nil
}
func (cpl *Compiler) compileLine() ([]byte, error) {
res := []byte{}
start, value, err := cpl.splitLine()
if err != nil || start == "" {
return nil, err
}
// Ignore lines starting with a comment.
if start[0] == '#' {
return nil, nil
}
// Save the position of the label.
if start[0] == '@' {
label := strings.Trim(start, "@:")
if _, ok := cpl.labelPositions[label]; ok {
return nil, ErrDuplicateLabel{label}
}
cpl.labelPositions[label] = cpl.codePos
return nil, nil
}
// Find the operator.
op, err := cpl.compileOp(start)
if err != nil {
return nil, err
}
res = append(res, byte(op))
// Find the value, of which there is at most one.
if value != "" {
val, err := cpl.compileValue(value)
if err != nil {
return nil, err
}
res = append(res, val...)
}
return res, nil
}
func (cpl *Compiler) compileOp(str string) (code.Op, error) {
op, err := StringToOp(str)
if err != nil {
return 0, err
}
return op, nil
}
func (cpl *Compiler) compileValue(str string) ([]byte, error) {
res := make([]byte, 8)
// Save label reference.
if str[0] == '@' {
label := strings.Trim(str, "@:")
cpl.labelReferences = append(cpl.labelReferences, labelReference{
label: label,
at: cpl.codePos + 1, // +1 to skip the opcode.
})
return res, nil
}
if unicode.IsDigit(rune(str[0])) || str[0] == '-' {
if strings.Contains(str, ".") {
val, err := strconv.ParseFloat(str, 64)
if err != nil {
return res, err
}
binary.LittleEndian.PutUint64(res, math.Float64bits(val))
} else {
val, err := strconv.ParseInt(str, 10, 64)
if err != nil {
return res, err
}
binary.LittleEndian.PutUint64(res, uint64(val))
}
return res, nil
}
if str[0] == '"' {
str = strings.Trim(str, "\"")
res = []byte(str)
res = append(res, 0)
return res, nil
}
return res, ErrInvalidValue{str}
}
func (cpl *Compiler) splitLine() (string, string, error) {
line := ""
for {
c, eof, err := cpl.src.Next()
if err != nil {
return "", "", err
}
if eof || c == '\n' {
break
}
line += string(c)
}
fields := strings.Fields(line)
if len(fields) == 0 {
return "", "", nil
}
start := fields[0]
if len(fields) > 1 {
return start, strings.Join(fields[1:], " "), nil
}
return start, "", nil
}
type labelReference struct {
label string
at int
}
func (cpl *Compiler) linkLabels(code []byte) error {
for _, ref := range cpl.labelReferences {
pos, ok := cpl.labelPositions[ref.label]
if !ok {
return ErrUnkonwnLabel{ref.label}
}
binary.LittleEndian.PutUint64(code[ref.at:], uint64(pos))
}
return nil
}
|
