code review 40600043: cmd/nm: reimplement in Go

src/cmd/nm/pe.go

Index: src/cmd/nm/pe.go
===================================================================
new file mode 100644
--- /dev/null
+++ b/src/cmd/nm/pe.go
@@ -0,0 +1,54 @@
+// Copyright 2013 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 PE executables (Microsoft Windows).
+
+package main
+
+import (
+	"debug/pe"
+	"os"
+)
+
+func peSymbols(f *os.File) []Sym {
+	p, err := pe.NewFile(f)
+	if err != nil {
+		errorf("parsing %s: %v", f.Name(), err)
+		return nil
+	}
+
+	var syms []Sym
+	for _, s := range p.Symbols {
+		sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'}
+		if s.SectionNumber == 0 {
+			sym.Code = 'U'
+		} else if int(s.SectionNumber) <= len(p.Sections) {
+			sect := p.Sections[s.SectionNumber-1]
+			const (
+				text  = 0x20
+				data  = 0x40
+				bss   = 0x80
+				permX = 0x20000000
+				permR = 0x40000000
+				permW = 0x80000000
+			)
+			ch := sect.Characteristics
+			switch {
+			case ch&text != 0:
+				sym.Code = 'T'
+			case ch&data != 0:
+				if ch&permW == 0 {
+					sym.Code = 'R'
+				} else {
+					sym.Code = 'D'
+				}
+			case ch&bss != 0:
+				sym.Code = 'B'
+			}
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms
+}