summaryrefslogtreecommitdiff
path: root/libgo/go/debug/gosym/pclntab_test.go
blob: e5c29889b7f8d5510d658cb5a761ecff70a412e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
// Copyright 2009 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 gosym

import (
	"debug/elf"
	"os"
	"syscall"
	"testing"
)

func dotest() bool {
	// For now, only works on ELF platforms.
	// TODO: convert to work with new go tool
	return false && syscall.OS == "linux" && os.Getenv("GOARCH") == "amd64"
}

func getTable(t *testing.T) *Table {
	f, tab := crack(os.Args[0], t)
	f.Close()
	return tab
}

func crack(file string, t *testing.T) (*elf.File, *Table) {
	// Open self
	f, err := elf.Open(file)
	if err != nil {
		t.Fatal(err)
	}
	return parse(file, f, t)
}

func parse(file string, f *elf.File, t *testing.T) (*elf.File, *Table) {
	symdat, err := f.Section(".gosymtab").Data()
	if err != nil {
		f.Close()
		t.Fatalf("reading %s gosymtab: %v", file, err)
	}
	pclndat, err := f.Section(".gopclntab").Data()
	if err != nil {
		f.Close()
		t.Fatalf("reading %s gopclntab: %v", file, err)
	}

	pcln := NewLineTable(pclndat, f.Section(".text").Addr)
	tab, err := NewTable(symdat, pcln)
	if err != nil {
		f.Close()
		t.Fatalf("parsing %s gosymtab: %v", file, err)
	}

	return f, tab
}

var goarch = os.Getenv("O")

func TestLineFromAline(t *testing.T) {
	if !dotest() {
		return
	}

	tab := getTable(t)

	// Find the sym package
	pkg := tab.LookupFunc("debug/gosym.TestLineFromAline").Obj
	if pkg == nil {
		t.Fatalf("nil pkg")
	}

	// Walk every absolute line and ensure that we hit every
	// source line monotonically
	lastline := make(map[string]int)
	final := -1
	for i := 0; i < 10000; i++ {
		path, line := pkg.lineFromAline(i)
		// Check for end of object
		if path == "" {
			if final == -1 {
				final = i - 1
			}
			continue
		} else if final != -1 {
			t.Fatalf("reached end of package at absolute line %d, but absolute line %d mapped to %s:%d", final, i, path, line)
		}
		// It's okay to see files multiple times (e.g., sys.a)
		if line == 1 {
			lastline[path] = 1
			continue
		}
		// Check that the is the next line in path
		ll, ok := lastline[path]
		if !ok {
			t.Errorf("file %s starts on line %d", path, line)
		} else if line != ll+1 {
			t.Errorf("expected next line of file %s to be %d, got %d", path, ll+1, line)
		}
		lastline[path] = line
	}
	if final == -1 {
		t.Errorf("never reached end of object")
	}
}

func TestLineAline(t *testing.T) {
	if !dotest() {
		return
	}

	tab := getTable(t)

	for _, o := range tab.Files {
		// A source file can appear multiple times in a
		// object.  alineFromLine will always return alines in
		// the first file, so track which lines we've seen.
		found := make(map[string]int)
		for i := 0; i < 1000; i++ {
			path, line := o.lineFromAline(i)
			if path == "" {
				break
			}

			// cgo files are full of 'Z' symbols, which we don't handle
			if len(path) > 4 && path[len(path)-4:] == ".cgo" {
				continue
			}

			if minline, ok := found[path]; path != "" && ok {
				if minline >= line {
					// We've already covered this file
					continue
				}
			}
			found[path] = line

			a, err := o.alineFromLine(path, line)
			if err != nil {
				t.Errorf("absolute line %d in object %s maps to %s:%d, but mapping that back gives error %s", i, o.Paths[0].Name, path, line, err)
			} else if a != i {
				t.Errorf("absolute line %d in object %s maps to %s:%d, which maps back to absolute line %d\n", i, o.Paths[0].Name, path, line, a)
			}
		}
	}
}

func TestPCLine(t *testing.T) {
	if !dotest() {
		return
	}

	f, tab := crack("_test/pclinetest", t)
	text := f.Section(".text")
	textdat, err := text.Data()
	if err != nil {
		t.Fatalf("reading .text: %v", err)
	}

	// Test PCToLine
	sym := tab.LookupFunc("linefrompc")
	wantLine := 0
	for pc := sym.Entry; pc < sym.End; pc++ {
		file, line, fn := tab.PCToLine(pc)
		off := pc - text.Addr // TODO(rsc): should not need off; bug in 8g
		wantLine += int(textdat[off])
		if fn == nil {
			t.Errorf("failed to get line of PC %#x", pc)
		} else if len(file) < 12 || file[len(file)-12:] != "pclinetest.s" || line != wantLine || fn != sym {
			t.Errorf("expected %s:%d (%s) at PC %#x, got %s:%d (%s)", "pclinetest.s", wantLine, sym.Name, pc, file, line, fn.Name)
		}
	}

	// Test LineToPC
	sym = tab.LookupFunc("pcfromline")
	lookupline := -1
	wantLine = 0
	off := uint64(0) // TODO(rsc): should not need off; bug in 8g
	for pc := sym.Value; pc < sym.End; pc += 2 + uint64(textdat[off]) {
		file, line, fn := tab.PCToLine(pc)
		off = pc - text.Addr
		wantLine += int(textdat[off])
		if line != wantLine {
			t.Errorf("expected line %d at PC %#x in pcfromline, got %d", wantLine, pc, line)
			off = pc + 1 - text.Addr
			continue
		}
		if lookupline == -1 {
			lookupline = line
		}
		for ; lookupline <= line; lookupline++ {
			pc2, fn2, err := tab.LineToPC(file, lookupline)
			if lookupline != line {
				// Should be nothing on this line
				if err == nil {
					t.Errorf("expected no PC at line %d, got %#x (%s)", lookupline, pc2, fn2.Name)
				}
			} else if err != nil {
				t.Errorf("failed to get PC of line %d: %s", lookupline, err)
			} else if pc != pc2 {
				t.Errorf("expected PC %#x (%s) at line %d, got PC %#x (%s)", pc, fn.Name, line, pc2, fn2.Name)
			}
		}
		off = pc + 1 - text.Addr
	}
}