1// Copyright 2014 The Go Authors.  All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// Copied and simplified from rsc.io/arm/armasm/objdumpext_test.go.
6
7package ppc64asm
8
9import (
10	"bytes"
11	"debug/elf"
12	"encoding/binary"
13	"fmt"
14	"io"
15	"log"
16	"os"
17	"runtime"
18	"strconv"
19	"strings"
20	"testing"
21)
22
23const objdumpPath = "/usr/bin/objdump"
24
25func testObjdump(t *testing.T, generate func(func([]byte))) {
26	if testing.Short() {
27		t.Skip("skipping objdump test in short mode")
28	}
29	if runtime.GOARCH != "ppc64le" && runtime.GOARCH != "ppc64" {
30		t.Skip("skipping; test requires host tool objdump for ppc64 or ppc64le")
31	}
32	if _, err := os.Stat(objdumpPath); err != nil {
33		t.Skip(err)
34	}
35
36	testExtDis(t, "gnu", objdump, generate, allowedMismatchObjdump)
37}
38
39func objdump(ext *ExtDis) error {
40	// File already written with instructions; add ELF header.
41	if err := writeELF64(ext.File, ext.Size); err != nil {
42		return err
43	}
44
45	b, err := ext.Run(objdumpPath, "-d", "-z", ext.File.Name())
46	if err != nil {
47		return err
48	}
49
50	var (
51		nmatch  int
52		reading bool
53		next    uint32 = start
54		addr    uint32
55		encbuf  [4]byte
56		enc     []byte
57		text    string
58	)
59	flush := func() {
60		if addr == next {
61			if m := pcrel.FindStringSubmatch(text); m != nil {
62				targ, _ := strconv.ParseUint(m[2], 16, 64)
63				text = fmt.Sprintf("%s.%+#x", m[1], int32(uint32(targ)-addr))
64			}
65			if strings.HasPrefix(text, "stmia") {
66				text = "stm" + text[5:]
67			}
68			if strings.HasPrefix(text, "stmfd") {
69				text = "stmdb" + text[5:]
70			}
71			if strings.HasPrefix(text, "ldmfd") {
72				text = "ldm" + text[5:]
73			}
74			text = strings.Replace(text, "#0.0", "#0", -1)
75			if text == "undefined" && len(enc) == 4 {
76				text = "error: unknown instruction"
77				enc = nil
78			}
79			if len(enc) == 4 {
80				// prints as word but we want to record bytes
81				enc[0], enc[3] = enc[3], enc[0]
82				enc[1], enc[2] = enc[2], enc[1]
83			}
84			ext.Dec <- ExtInst{addr, encbuf, len(enc), text}
85			encbuf = [4]byte{}
86			enc = nil
87			next += 4
88		}
89	}
90	var textangle = []byte("<.text>:")
91	for {
92		line, err := b.ReadSlice('\n')
93		if err != nil {
94			if err == io.EOF {
95				break
96			}
97			return fmt.Errorf("reading objdump output: %v", err)
98		}
99		if bytes.Contains(line, textangle) {
100			reading = true
101			continue
102		}
103		if !reading {
104			continue
105		}
106		if debug {
107			os.Stdout.Write(line)
108		}
109		if enc1 := parseContinuation(line, encbuf[:len(enc)]); enc1 != nil {
110			enc = enc1
111			continue
112		}
113		flush()
114		nmatch++
115		addr, enc, text = parseLine(line, encbuf[:0])
116		if addr > next {
117			return fmt.Errorf("address out of sync expected <= %#x at %q in:\n%s", next, line, line)
118		}
119	}
120	flush()
121	if next != start+uint32(ext.Size) {
122		return fmt.Errorf("not enough results found [%d %d]", next, start+ext.Size)
123	}
124	if err := ext.Wait(); err != nil {
125		return fmt.Errorf("exec: %v", err)
126	}
127
128	return nil
129}
130
131var (
132	undefined      = []byte("<UNDEFINED>")
133	unpredictable  = []byte("<UNPREDICTABLE>")
134	illegalShifter = []byte("<illegal shifter operand>")
135)
136
137func parseLine(line []byte, encstart []byte) (addr uint32, enc []byte, text string) {
138	oline := line
139	i := index(line, ":\t")
140	if i < 0 {
141		log.Fatalf("cannot parse disassembly: %q", oline)
142	}
143	x, err := strconv.ParseUint(string(trimSpace(line[:i])), 16, 32)
144	if err != nil {
145		log.Fatalf("cannot parse disassembly: %q", oline)
146	}
147	addr = uint32(x)
148	line = line[i+2:]
149	i = bytes.IndexByte(line, '\t')
150	if i < 0 {
151		log.Fatalf("cannot parse disassembly: %q", oline)
152	}
153	enc, ok := parseHex(line[:i], encstart)
154	if !ok {
155		log.Fatalf("cannot parse disassembly: %q", oline)
156	}
157	line = trimSpace(line[i:])
158	if bytes.Contains(line, undefined) {
159		text = "undefined"
160		return
161	}
162	if bytes.Contains(line, illegalShifter) {
163		text = "undefined"
164		return
165	}
166	if false && bytes.Contains(line, unpredictable) {
167		text = "unpredictable"
168		return
169	}
170	if i := bytes.IndexByte(line, ';'); i >= 0 {
171		line = trimSpace(line[:i])
172	}
173	text = string(fixSpace(line))
174	return
175}
176
177func parseContinuation(line []byte, enc []byte) []byte {
178	i := index(line, ":\t")
179	if i < 0 {
180		return nil
181	}
182	line = line[i+1:]
183	enc, _ = parseHex(line, enc)
184	return enc
185}
186
187// writeELF64 writes an ELF64 header to the file,
188// describing a text segment that starts at start
189// and extends for size bytes.
190func writeELF64(f *os.File, size int) error {
191	f.Seek(0, 0)
192	var hdr elf.Header64
193	var prog elf.Prog64
194	var sect elf.Section64
195	var buf bytes.Buffer
196	binary.Write(&buf, binary.BigEndian, &hdr)
197	off1 := buf.Len()
198	binary.Write(&buf, binary.BigEndian, &prog)
199	off2 := buf.Len()
200	binary.Write(&buf, binary.BigEndian, &sect)
201	off3 := buf.Len()
202	buf.Reset()
203	data := byte(elf.ELFDATA2MSB)
204	hdr = elf.Header64{
205		Ident:     [16]byte{0x7F, 'E', 'L', 'F', 2, data, 1},
206		Type:      2,
207		Machine:   uint16(elf.EM_PPC64),
208		Version:   1,
209		Entry:     start,
210		Phoff:     uint64(off1),
211		Shoff:     uint64(off2),
212		Flags:     0x05000002,
213		Ehsize:    uint16(off1),
214		Phentsize: uint16(off2 - off1),
215		Phnum:     1,
216		Shentsize: uint16(off3 - off2),
217		Shnum:     3,
218		Shstrndx:  2,
219	}
220	binary.Write(&buf, binary.BigEndian, &hdr)
221	prog = elf.Prog64{
222		Type:   1,
223		Off:    start,
224		Vaddr:  start,
225		Paddr:  start,
226		Filesz: uint64(size),
227		Memsz:  uint64(size),
228		Flags:  5,
229		Align:  start,
230	}
231	binary.Write(&buf, binary.BigEndian, &prog)
232	binary.Write(&buf, binary.BigEndian, &sect) // NULL section
233	sect = elf.Section64{
234		Name:      1,
235		Type:      uint32(elf.SHT_PROGBITS),
236		Addr:      start,
237		Off:       start,
238		Size:      uint64(size),
239		Flags:     uint64(elf.SHF_ALLOC | elf.SHF_EXECINSTR),
240		Addralign: 4,
241	}
242	binary.Write(&buf, binary.BigEndian, &sect) // .text
243	sect = elf.Section64{
244		Name:      uint32(len("\x00.text\x00")),
245		Type:      uint32(elf.SHT_STRTAB),
246		Addr:      0,
247		Off:       uint64(off2 + (off3-off2)*3),
248		Size:      uint64(len("\x00.text\x00.shstrtab\x00")),
249		Addralign: 1,
250	}
251	binary.Write(&buf, binary.BigEndian, &sect)
252	buf.WriteString("\x00.text\x00.shstrtab\x00")
253	f.Write(buf.Bytes())
254	return nil
255}
256