func (b *Builder) link(out io.Writer, p *pkg, main string) error {
var funcs []*link8.PkgSym
addInit := func(p *pkg) {
name := p.pkg.Init
if name != "" && p.pkg.Lib.HasFunc(name) {
funcs = append(funcs, &link8.PkgSym{p.path, name})
}
}
for _, dep := range p.deps {
addInit(b.pkgs[dep])
}
addInit(p)
funcs = append(funcs, &link8.PkgSym{p.path, main})
debugTable := debug8.NewTable()
job := link8.NewJob(b.linkPkgs, funcs)
job.InitPC = b.InitPC
job.FuncDebug = func(pkg, name string, addr, size uint32) {
debugTable.LinkFunc(b.debugFuncs, pkg, name, addr, size)
}
secs, err := job.Link()
if err != nil {
return err
}
debugSec, err := debugSection(debugTable)
if err != nil {
return err
}
secs = append(secs, debugSec)
return e8.Write(out, secs)
}
// LinkBareFunc produces a image of a single function that has no links.
func LinkBareFunc(f *Func) ([]byte, error) {
if f.TooLarge() {
return nil, fmt.Errorf("code section too large")
}
buf := new(bytes.Buffer)
w := newWriter(make(map[string]*Pkg), buf)
w.writeBareFunc(f)
if err := w.Err(); err != nil {
return nil, err
}
image := new(bytes.Buffer)
sec := &e8.Section{
Header: &e8.Header{
Type: e8.Code,
Addr: arch8.InitPC,
},
Bytes: buf.Bytes(),
}
if err := e8.Write(image, []*e8.Section{sec}); err != nil {
return nil, err
}
return image.Bytes(), nil
}
// BuildSingleFile builds a package named "main" from a single file.
func BuildSingleFile(f string, rc io.ReadCloser) ([]byte, []*lex8.Error) {
path := "_"
pinfo := build8.SimplePkg(path, f, rc)
pkg, errs := Lang().Compile(pinfo, new(build8.Options))
if errs != nil {
return nil, errs
}
secs, err := link8.LinkSinglePkg(pkg.Lib, pkg.Main)
if err != nil {
return nil, lex8.SingleErr(err)
}
buf := new(bytes.Buffer)
if err := e8.Write(buf, secs); err != nil {
return nil, lex8.SingleErr(err)
}
return buf.Bytes(), nil
}