libgo/go/debug/gosym/pclntab_test.go - gofrontend - Git at Google

 // 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 (
 	"bytes"
 	"debug/elf"
 	"internal/testenv"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
 )

 var (
 	pclineTempDir    string
 	pclinetestBinary string
 )

 func dotest(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
 	// For now, only works on amd64 platforms.
 	if runtime.GOARCH != "amd64" {
 		t.Skipf("skipping on non-AMD64 system %s", runtime.GOARCH)
 	}
 	var err error
 	pclineTempDir, err = ioutil.TempDir("", "pclinetest")
 	if err != nil {
 		t.Fatal(err)
 	}
 	// This command builds pclinetest from pclinetest.asm;
 	// the resulting binary looks like it was built from pclinetest.s,
 	// but we have renamed it to keep it away from the go tool.
 	pclinetestBinary = filepath.Join(pclineTempDir, "pclinetest")
 	cmd := exec.Command(testenv.GoToolPath(t), "tool", "asm", "-o", pclinetestBinary+".o", "pclinetest.asm")
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	if err := cmd.Run(); err != nil {
 		t.Fatal(err)
 	}

 	// stamp .o file as being 'package main' so that go tool link will accept it
 	data, err := ioutil.ReadFile(pclinetestBinary + ".o")
 	if err != nil {
 		t.Fatal(err)
 	}
 	i := bytes.IndexByte(data, '\n')
 	if i < 0 {
 		t.Fatal("bad binary")
 	}
 	data = append(append(data[:i:i], "\nmain"...), data[i:]...)
 	if err := ioutil.WriteFile(pclinetestBinary+".o", data, 0666); err != nil {
 		t.Fatal(err)
 	}

 	cmd = exec.Command(testenv.GoToolPath(t), "tool", "link", "-H", "linux",
 		"-o", pclinetestBinary, pclinetestBinary+".o")
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	if err := cmd.Run(); err != nil {
 		t.Fatal(err)
 	}
 }

 func endtest() {
 	if pclineTempDir != "" {
 		os.RemoveAll(pclineTempDir)
 		pclineTempDir = ""
 		pclinetestBinary = ""
 	}
 }

 // skipIfNotELF skips the test if we are not running on an ELF system.
 // These tests open and examine the test binary, and use elf.Open to do so.
 func skipIfNotELF(t *testing.T) {
 	switch runtime.GOOS {
 	case "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "solaris":
 		// OK.
 	default:
 		t.Skipf("skipping on non-ELF system %s", runtime.GOOS)
 	}
 }

 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) {
 	s := f.Section(".gosymtab")
 	if s == nil {
 		t.Skip("no .gosymtab section")
 	}
 	symdat, err := s.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
 }

 func TestLineFromAline(t *testing.T) {
 	skipIfNotELF(t)

 	tab := getTable(t)
 	if tab.go12line != nil {
 		// aline's don't exist in the Go 1.2 table.
 		t.Skip("not relevant to Go 1.2 symbol table")
 	}

 	// 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.Fatalf("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) {
 	skipIfNotELF(t)

 	tab := getTable(t)
 	if tab.go12line != nil {
 		// aline's don't exist in the Go 1.2 table.
 		t.Skip("not relevant to Go 1.2 symbol table")
 	}

 	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) {
 	dotest(t)
 	defer endtest()

 	f, tab := crack(pclinetestBinary, t)
 	defer f.Close()
 	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++ {
 		off := pc - text.Addr // TODO(rsc): should not need off; bug in 8g
 		if textdat[off] == 255 {
 			break
 		}
 		wantLine += int(textdat[off])
 		t.Logf("off is %d %#x (max %d)", off, textdat[off], sym.End-pc)
 		file, line, fn := tab.PCToLine(pc)
 		if fn == nil {
 			t.Errorf("failed to get line of PC %#x", pc)
 		} else if !strings.HasSuffix(file, "pclinetest.asm") || line != wantLine || fn != sym {
 			t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.asm", wantLine, sym.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
 		if textdat[off] == 255 {
 			break
 		}
 		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
 	}
 }
	// 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 (
	"bytes"
	"debug/elf"
	"internal/testenv"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	)

	var (
	pclineTempDir string
	pclinetestBinary string
	)

	func dotest(t *testing.T) {
	testenv.MustHaveGoBuild(t)
	// For now, only works on amd64 platforms.
	if runtime.GOARCH != "amd64" {
	t.Skipf("skipping on non-AMD64 system %s", runtime.GOARCH)
	}
	var err error
	pclineTempDir, err = ioutil.TempDir("", "pclinetest")
	if err != nil {
	t.Fatal(err)
	}
	// This command builds pclinetest from pclinetest.asm;
	// the resulting binary looks like it was built from pclinetest.s,
	// but we have renamed it to keep it away from the go tool.
	pclinetestBinary = filepath.Join(pclineTempDir, "pclinetest")
	cmd := exec.Command(testenv.GoToolPath(t), "tool", "asm", "-o", pclinetestBinary+".o", "pclinetest.asm")
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
	t.Fatal(err)
	}

	// stamp .o file as being 'package main' so that go tool link will accept it
	data, err := ioutil.ReadFile(pclinetestBinary + ".o")
	if err != nil {
	t.Fatal(err)
	}
	i := bytes.IndexByte(data, '\n')
	if i < 0 {
	t.Fatal("bad binary")
	}
	data = append(append(data[:i:i], "\nmain"...), data[i:]...)
	if err := ioutil.WriteFile(pclinetestBinary+".o", data, 0666); err != nil {
	t.Fatal(err)
	}

	cmd = exec.Command(testenv.GoToolPath(t), "tool", "link", "-H", "linux",
	"-o", pclinetestBinary, pclinetestBinary+".o")
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
	t.Fatal(err)
	}
	}

	func endtest() {
	if pclineTempDir != "" {
	os.RemoveAll(pclineTempDir)
	pclineTempDir = ""
	pclinetestBinary = ""
	}
	}

	// skipIfNotELF skips the test if we are not running on an ELF system.
	// These tests open and examine the test binary, and use elf.Open to do so.
	func skipIfNotELF(t *testing.T) {
	switch runtime.GOOS {
	case "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "solaris":
	// OK.
	default:
	t.Skipf("skipping on non-ELF system %s", runtime.GOOS)
	}
	}

	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) {
	s := f.Section(".gosymtab")
	if s == nil {
	t.Skip("no .gosymtab section")
	}
	symdat, err := s.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
	}

	func TestLineFromAline(t *testing.T) {
	skipIfNotELF(t)

	tab := getTable(t)
	if tab.go12line != nil {
	// aline's don't exist in the Go 1.2 table.
	t.Skip("not relevant to Go 1.2 symbol table")
	}

	// 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.Fatalf("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) {
	skipIfNotELF(t)

	tab := getTable(t)
	if tab.go12line != nil {
	// aline's don't exist in the Go 1.2 table.
	t.Skip("not relevant to Go 1.2 symbol table")
	}

	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) {
	dotest(t)
	defer endtest()

	f, tab := crack(pclinetestBinary, t)
	defer f.Close()
	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++ {
	off := pc - text.Addr // TODO(rsc): should not need off; bug in 8g
	if textdat[off] == 255 {
	break
	}
	wantLine += int(textdat[off])
	t.Logf("off is %d %#x (max %d)", off, textdat[off], sym.End-pc)
	file, line, fn := tab.PCToLine(pc)
	if fn == nil {
	t.Errorf("failed to get line of PC %#x", pc)
	} else if !strings.HasSuffix(file, "pclinetest.asm") \|\| line != wantLine \|\| fn != sym {
	t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.asm", wantLine, sym.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
	if textdat[off] == 255 {
	break
	}
	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
	}
	}