diff options
Diffstat (limited to 'vendor/github.com/google/gops/internal/objfile/objfile.go')
-rw-r--r-- | vendor/github.com/google/gops/internal/objfile/objfile.go | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/vendor/github.com/google/gops/internal/objfile/objfile.go b/vendor/github.com/google/gops/internal/objfile/objfile.go new file mode 100644 index 00000000..a884a20d --- /dev/null +++ b/vendor/github.com/google/gops/internal/objfile/objfile.go @@ -0,0 +1,129 @@ +// 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. + +// Package objfile implements portable access to OS-specific executable files. +package objfile + +import ( + "debug/dwarf" + "debug/gosym" + "fmt" + "os" + "sort" +) + +type rawFile interface { + symbols() (syms []Sym, err error) + pcln() (textStart uint64, symtab, pclntab []byte, err error) + text() (textStart uint64, text []byte, err error) + goarch() string + loadAddress() (uint64, error) + dwarf() (*dwarf.Data, error) +} + +// A File is an opened executable file. +type File struct { + r *os.File + raw rawFile +} + +// A Sym is a symbol defined in an executable file. +type Sym struct { + Name string // symbol name + Addr uint64 // virtual address of symbol + Size int64 // size in bytes + Code rune // nm code (T for text, D for data, and so on) + Type string // XXX? + Relocs []Reloc // in increasing Addr order +} + +type Reloc struct { + Addr uint64 // Address of first byte that reloc applies to. + Size uint64 // Number of bytes + Stringer RelocStringer +} + +type RelocStringer interface { + // insnOffset is the offset of the instruction containing the relocation + // from the start of the symbol containing the relocation. + String(insnOffset uint64) string +} + +var openers = []func(*os.File) (rawFile, error){ + openElf, + // openGoobj, // TODO(jbd): Bring it back when 1.8 is popular. + openMacho, + openPE, + openPlan9, +} + +// Open opens the named file. +// The caller must call f.Close when the file is no longer needed. +func Open(name string) (*File, error) { + r, err := os.Open(name) + if err != nil { + return nil, err + } + for _, try := range openers { + if raw, err := try(r); err == nil { + return &File{r, raw}, nil + } + } + r.Close() + return nil, fmt.Errorf("open %s: unrecognized object file", name) +} + +func (f *File) Close() error { + return f.r.Close() +} + +func (f *File) Symbols() ([]Sym, error) { + syms, err := f.raw.symbols() + if err != nil { + return nil, err + } + sort.Sort(byAddr(syms)) + return syms, nil +} + +type byAddr []Sym + +func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr } +func (x byAddr) Len() int { return len(x) } +func (x byAddr) Swap(i, j int) { x[i], x[j] = x[j], x[i] } + +func (f *File) PCLineTable() (Liner, error) { + // If the raw file implements Liner directly, use that. + // Currently, only Go intermediate objects and archives (goobj) use this path. + if pcln, ok := f.raw.(Liner); ok { + return pcln, nil + } + // Otherwise, read the pcln tables and build a Liner out of that. + textStart, symtab, pclntab, err := f.raw.pcln() + if err != nil { + return nil, err + } + return gosym.NewTable(symtab, gosym.NewLineTable(pclntab, textStart)) +} + +func (f *File) Text() (uint64, []byte, error) { + return f.raw.text() +} + +func (f *File) GOARCH() string { + return f.raw.goarch() +} + +// LoadAddress returns the expected load address of the file. +// This differs from the actual load address for a position-independent +// executable. +func (f *File) LoadAddress() (uint64, error) { + return f.raw.loadAddress() +} + +// DWARF returns DWARF debug data for the file, if any. +// This is for cmd/pprof to locate cgo functions. +func (f *File) DWARF() (*dwarf.Data, error) { + return f.raw.dwarf() +} |