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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
commit | 73df946d56c74384511a194dd01dbe099584fd1a (patch) | |
tree | fd0bcea490dd81327ddfbb31e215439672c9a068 /src/cmd/internal/objfile/plan9obj.go | |
parent | Initial commit. (diff) | |
download | golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip |
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/cmd/internal/objfile/plan9obj.go')
-rw-r--r-- | src/cmd/internal/objfile/plan9obj.go | 156 |
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") +} |