Skip to content

Commit

Permalink
Support parsing the 'importmap' directive in an importcfg file.
Browse files Browse the repository at this point in the history 
Also change Parse to take in a function instead of a map to give the caller additional flexibility.

Fixes #13 and #17.
  • Loading branch information
@capnspacehook
capnspacehook committed Nov 8, 2020
1 parent d867f0b commit 2b85042
Showing 1 changed file with 40 additions and 26 deletions.
66 changes: 40 additions & 26 deletions goobj2/file.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -194,24 +194,29 @@ const (
SLIBFUZZER_EXTRA_COUNTER
)

type ImportCfg map[string]ExportInfo
type ImportCfg struct {
ImportMap map[string]string
Packages map[string]ExportInfo
}

type ExportInfo struct {
Path string
IsSharedLib bool
}

func ParseImportCfg(path string) (ImportCfg, error) {
func ParseImportCfg(path string) (importCfg ImportCfg, err error) {
data, err := ioutil.ReadFile(path)
if err != nil {
return nil, fmt.Errorf("error reading importcfg: %v", err)
return importCfg, fmt.Errorf("error reading importcfg: %v", err)
}

lines := bytes.Count(data, []byte("\n"))
if lines == -1 {
return nil, errors.New("error parsing importcfg: could not find any newlines")
return importCfg, errors.New("error parsing importcfg: could not find any newlines")
}
importMap := make(ImportCfg, lines)

importCfg.ImportMap = make(map[string]string)
importCfg.Packages = make(map[string]ExportInfo, lines)

for lineNum, line := range strings.Split(string(data), "\n") {
lineNum++ // 1-based
Expand All @@ -235,21 +240,26 @@ func ParseImportCfg(path string) (ImportCfg, error) {
}
switch verb {
default:
return nil, fmt.Errorf("error parsing importcfg: %s:%d: unknown directive %q", path, lineNum, verb)
return importCfg, fmt.Errorf("error parsing importcfg: %s:%d: unknown directive %q", path, lineNum, verb)
case "importmap":
if before == "" || after == "" {
return importCfg, fmt.Errorf(`error parsing importcfg: %s:%d: invalid importmap: syntax is "importmap path=path"`, path, lineNum)
}
importCfg.ImportMap[before] = after
case "packagefile":
if before == "" || after == "" {
return nil, fmt.Errorf(`error parsing importcfg: %s:%d: invalid packagefile: syntax is "packagefile path=filename"`, path, lineNum)
return importCfg, fmt.Errorf(`error parsing importcfg: %s:%d: invalid packagefile: syntax is "packagefile path=filename"`, path, lineNum)
}
importMap[before] = ExportInfo{after, false}
importCfg.Packages[before] = ExportInfo{after, false}
case "packageshlib":
if before == "" || after == "" {
return nil, fmt.Errorf(`error parsing importcfg: %s:%d: invalid packageshlib: syntax is "packageshlib path=filename"`, path, lineNum)
return importCfg, fmt.Errorf(`error parsing importcfg: %s:%d: invalid packageshlib: syntax is "packageshlib path=filename"`, path, lineNum)
}
importMap[before] = ExportInfo{after, true}
importCfg.Packages[before] = ExportInfo{after, true}
}
}

return importMap, nil
return importCfg, nil
}

var (
Expand Down Expand Up @@ -416,22 +426,27 @@ func (r *objReader) skip(n int64) {
}
}

// Parse parses an object file or archive from f, assuming that its
// import path is pkgpath. An import configuration file that would
// be passed into the linker can optionally be passed in as importCfg
// ImportMap is a function that returns the path of a Go object
// from a given import path. If the import path is not known,
// an empty string should be returned.
type ImportMap = func(importPath string) (objectPath string)

// Parse parses an object file or archive from objPath, assuming that
// its import path is pkgpath. A function that returns paths of object
// files from import paths can optionally be passed in as importMap
// to optimize looking up paths to dependencies' object files.
func Parse(objPath, pkgPath string, importCfg ImportCfg) (*Package, error) {
func Parse(objPath, pkgPath string, importMap ImportMap) (*Package, error) {
p := new(Package)
p.ImportPath = pkgPath

if _, err := parse(objPath, p, importCfg, false); err != nil {
if _, err := parse(objPath, p, importMap, false); err != nil {
return nil, err
}

return p, nil
}

func parse(objPath string, p *Package, importCfg ImportCfg, returnReader bool) (rr *goobj2.Reader, err error) {
func parse(objPath string, p *Package, importMap ImportMap, returnReader bool) (rr *goobj2.Reader, err error) {
f, openErr := os.Open(objPath)
if err != nil {
return nil, openErr
Expand All @@ -457,13 +472,13 @@ func parse(objPath string, p *Package, importCfg ImportCfg, returnReader bool) (
default:
return nil, errNotObject
case bytes.Equal(rd.tmp[:8], archiveHeader):
rr, err = rd.parseArchive(importCfg, returnReader)
rr, err = rd.parseArchive(importMap, returnReader)
if err != nil {
return nil, err
}
case bytes.Equal(rd.tmp[:8], goobjHeader):
var am *ArchiveMember
rr, am, _, err = rd.parseObject(goobjHeader, importCfg, returnReader)
rr, am, _, err = rd.parseObject(goobjHeader, importMap, returnReader)
if err != nil {
return nil, err
}
Expand All @@ -480,7 +495,7 @@ func trimSpace(b []byte) string {
}

// parseArchive parses a Unix archive of Go object files.
func (r *objReader) parseArchive(importCfg ImportCfg, returnReader bool) (*goobj2.Reader, error) {
func (r *objReader) parseArchive(importMap ImportMap, returnReader bool) (*goobj2.Reader, error) {
for r.offset < r.limit {
if err := r.readFull(r.tmp[:archiveHeaderLen]); err != nil {
return nil, err
Expand Down Expand Up @@ -551,7 +566,7 @@ func (r *objReader) parseArchive(importCfg ImportCfg, returnReader bool) (*goobj
}
if bytes.Equal(p, goobjHeader) {
var rr *goobj2.Reader
rr, am, data, err = r.parseObject(nil, importCfg, returnReader)
rr, am, data, err = r.parseObject(nil, importMap, returnReader)
if err != nil {
return nil, fmt.Errorf("parsing archive member %q: %v", ar.Name, err)
}
Expand Down Expand Up @@ -593,7 +608,7 @@ func (r *objReader) parseArchive(importCfg ImportCfg, returnReader bool) (*goobj
// and then the part we want to parse begins.
// The format of that part is defined in a comment at the top
// of src/liblink/objfile.c.
func (r *objReader) parseObject(prefix []byte, importMap ImportCfg, returnReader bool) (*goobj2.Reader, *ArchiveMember, []byte, error) {
func (r *objReader) parseObject(prefix []byte, importMap ImportMap, returnReader bool) (*goobj2.Reader, *ArchiveMember, []byte, error) {
h := make([]byte, 0, 256)
h = append(h, prefix...)
var c1, c2, c3 byte
Expand Down Expand Up @@ -887,12 +902,11 @@ func (r *objReader) parseObject(prefix []byte, importMap ImportCfg, returnReader
return nil, &am, h, nil
}

func getArchivePath(pkg string, importMap ImportCfg) (s string, err error) {
func getArchivePath(pkg string, importMap ImportMap) (s string, err error) {
// try to get the archive path from the importMap first
if importMap != nil {
path, ok := importMap[pkg]
if ok {
return path.Path, nil
if path := importMap(pkg); path != "" {
return path, nil
}
}

Expand Down

0 comments on commit 2b85042

Please sign in to comment.