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-rw-r--r--src/cmd/internal/objfile/plan9obj.go156
1 files changed, 156 insertions, 0 deletions
diff --git a/src/cmd/internal/objfile/plan9obj.go b/src/cmd/internal/objfile/plan9obj.go
new file mode 100644
index 0000000..da0b345
--- /dev/null
+++ b/src/cmd/internal/objfile/plan9obj.go
@@ -0,0 +1,156 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parsing of Plan 9 a.out executables.
+
+package objfile
+
+import (
+ "debug/dwarf"
+ "debug/plan9obj"
+ "errors"
+ "fmt"
+ "io"
+ "sort"
+)
+
+var validSymType = map[rune]bool{
+ 'T': true,
+ 't': true,
+ 'D': true,
+ 'd': true,
+ 'B': true,
+ 'b': true,
+}
+
+type plan9File struct {
+ plan9 *plan9obj.File
+}
+
+func openPlan9(r io.ReaderAt) (rawFile, error) {
+ f, err := plan9obj.NewFile(r)
+ if err != nil {
+ return nil, err
+ }
+ return &plan9File{f}, nil
+}
+
+func (f *plan9File) symbols() ([]Sym, error) {
+ plan9Syms, err := f.plan9.Symbols()
+ if err != nil {
+ return nil, err
+ }
+
+ // Build sorted list of addresses of all symbols.
+ // We infer the size of a symbol by looking at where the next symbol begins.
+ var addrs []uint64
+ for _, s := range plan9Syms {
+ if !validSymType[s.Type] {
+ continue
+ }
+ addrs = append(addrs, s.Value)
+ }
+ sort.Sort(uint64s(addrs))
+
+ var syms []Sym
+
+ for _, s := range plan9Syms {
+ if !validSymType[s.Type] {
+ continue
+ }
+ sym := Sym{Addr: s.Value, Name: s.Name, Code: s.Type}
+ i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
+ if i < len(addrs) {
+ sym.Size = int64(addrs[i] - s.Value)
+ }
+ syms = append(syms, sym)
+ }
+
+ return syms, nil
+}
+
+func (f *plan9File) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+ textStart = f.plan9.LoadAddress + f.plan9.HdrSize
+ if pclntab, err = loadPlan9Table(f.plan9, "runtime.pclntab", "runtime.epclntab"); err != nil {
+ // We didn't find the symbols, so look for the names used in 1.3 and earlier.
+ // TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+ var err2 error
+ if pclntab, err2 = loadPlan9Table(f.plan9, "pclntab", "epclntab"); err2 != nil {
+ return 0, nil, nil, err
+ }
+ }
+ if symtab, err = loadPlan9Table(f.plan9, "runtime.symtab", "runtime.esymtab"); err != nil {
+ // Same as above.
+ var err2 error
+ if symtab, err2 = loadPlan9Table(f.plan9, "symtab", "esymtab"); err2 != nil {
+ return 0, nil, nil, err
+ }
+ }
+ return textStart, symtab, pclntab, nil
+}
+
+func (f *plan9File) text() (textStart uint64, text []byte, err error) {
+ sect := f.plan9.Section("text")
+ if sect == nil {
+ return 0, nil, fmt.Errorf("text section not found")
+ }
+ textStart = f.plan9.LoadAddress + f.plan9.HdrSize
+ text, err = sect.Data()
+ return
+}
+
+func findPlan9Symbol(f *plan9obj.File, name string) (*plan9obj.Sym, error) {
+ syms, err := f.Symbols()
+ if err != nil {
+ return nil, err
+ }
+ for _, s := range syms {
+ if s.Name != name {
+ continue
+ }
+ return &s, nil
+ }
+ return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPlan9Table(f *plan9obj.File, sname, ename string) ([]byte, error) {
+ ssym, err := findPlan9Symbol(f, sname)
+ if err != nil {
+ return nil, err
+ }
+ esym, err := findPlan9Symbol(f, ename)
+ if err != nil {
+ return nil, err
+ }
+ sect := f.Section("text")
+ if sect == nil {
+ return nil, err
+ }
+ data, err := sect.Data()
+ if err != nil {
+ return nil, err
+ }
+ textStart := f.LoadAddress + f.HdrSize
+ return data[ssym.Value-textStart : esym.Value-textStart], nil
+}
+
+func (f *plan9File) goarch() string {
+ switch f.plan9.Magic {
+ case plan9obj.Magic386:
+ return "386"
+ case plan9obj.MagicAMD64:
+ return "amd64"
+ case plan9obj.MagicARM:
+ return "arm"
+ }
+ return ""
+}
+
+func (f *plan9File) loadAddress() (uint64, error) {
+ return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *plan9File) dwarf() (*dwarf.Data, error) {
+ return nil, errors.New("no DWARF data in Plan 9 file")
+}