1 files changed, 163 insertions, 0 deletions
diff --git a/src/cmd/internal/objfile/xcoff.go b/src/cmd/internal/objfile/xcoff.go
new file mode 100644
index 0000000..d6df4db
--- /dev/null
+++ b/src/cmd/internal/objfile/xcoff.go
@@ -0,0 +1,163 @@
+// Copyright 2018 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 XCOFF executable (AIX)
+
+package objfile
+
+import (
+	"debug/dwarf"
+	"fmt"
+	"internal/xcoff"
+	"io"
+	"unicode"
+)
+
+type xcoffFile struct {
+	xcoff *xcoff.File
+}
+
+func openXcoff(r io.ReaderAt) (rawFile, error) {
+	f, err := xcoff.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	return &xcoffFile{f}, nil
+}
+
+func (f *xcoffFile) symbols() ([]Sym, error) {
+	var syms []Sym
+	for _, s := range f.xcoff.Symbols {
+		const (
+			N_UNDEF = 0  // An undefined (extern) symbol
+			N_ABS   = -1 // An absolute symbol (e_value is a constant, not an address)
+			N_DEBUG = -2 // A debugging symbol
+		)
+		sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'}
+
+		switch s.SectionNumber {
+		case N_UNDEF:
+			sym.Code = 'U'
+		case N_ABS:
+			sym.Code = 'C'
+		case N_DEBUG:
+			sym.Code = '?'
+		default:
+			if s.SectionNumber < 0 || len(f.xcoff.Sections) < int(s.SectionNumber) {
+				return nil, fmt.Errorf("invalid section number in symbol table")
+			}
+			sect := f.xcoff.Sections[s.SectionNumber-1]
+
+			// debug/xcoff returns an offset in the section not the actual address
+			sym.Addr += sect.VirtualAddress
+
+			if s.AuxCSect.SymbolType&0x3 == xcoff.XTY_LD {
+				// The size of a function is contained in the
+				// AUX_FCN entry
+				sym.Size = s.AuxFcn.Size
+			} else {
+				sym.Size = s.AuxCSect.Length
+			}
+
+			sym.Size = s.AuxCSect.Length
+
+			switch sect.Type {
+			case xcoff.STYP_TEXT:
+				if s.AuxCSect.StorageMappingClass == xcoff.XMC_RO {
+					sym.Code = 'R'
+				} else {
+					sym.Code = 'T'
+				}
+			case xcoff.STYP_DATA:
+				sym.Code = 'D'
+			case xcoff.STYP_BSS:
+				sym.Code = 'B'
+			}
+
+			if s.StorageClass == xcoff.C_HIDEXT {
+				// Local symbol
+				sym.Code = unicode.ToLower(sym.Code)
+			}
+
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms, nil
+}
+
+func (f *xcoffFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	if sect := f.xcoff.Section(".text"); sect != nil {
+		textStart = sect.VirtualAddress
+	}
+	if pclntab, err = loadXCOFFTable(f.xcoff, "runtime.pclntab", "runtime.epclntab"); err != nil {
+		return 0, nil, nil, err
+	}
+	symtab, _ = loadXCOFFTable(f.xcoff, "runtime.symtab", "runtime.esymtab") // ignore error, this symbol is not useful anyway
+	return textStart, symtab, pclntab, nil
+}
+
+func (f *xcoffFile) text() (textStart uint64, text []byte, err error) {
+	sect := f.xcoff.Section(".text")
+	if sect == nil {
+		return 0, nil, fmt.Errorf("text section not found")
+	}
+	textStart = sect.VirtualAddress
+	text, err = sect.Data()
+	return
+}
+
+func findXCOFFSymbol(f *xcoff.File, name string) (*xcoff.Symbol, error) {
+	for _, s := range f.Symbols {
+		if s.Name != name {
+			continue
+		}
+		if s.SectionNumber <= 0 {
+			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
+		}
+		if len(f.Sections) < int(s.SectionNumber) {
+			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
+		}
+		return s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadXCOFFTable(f *xcoff.File, sname, ename string) ([]byte, error) {
+	ssym, err := findXCOFFSymbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findXCOFFSymbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	if ssym.SectionNumber != esym.SectionNumber {
+		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
+	}
+	sect := f.Sections[ssym.SectionNumber-1]
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	return data[ssym.Value:esym.Value], nil
+}
+
+func (f *xcoffFile) goarch() string {
+	switch f.xcoff.TargetMachine {
+	case xcoff.U802TOCMAGIC:
+		return "ppc"
+	case xcoff.U64_TOCMAGIC:
+		return "ppc64"
+	}
+	return ""
+}
+
+func (f *xcoffFile) loadAddress() (uint64, error) {
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *xcoffFile) dwarf() (*dwarf.Data, error) {
+	return f.xcoff.DWARF()
+}