1 files changed, 407 insertions, 0 deletions
diff --git a/src/debug/gosym/pclntab_test.go b/src/debug/gosym/pclntab_test.go
new file mode 100644
index 0000000..e380bb5
--- /dev/null
+++ b/src/debug/gosym/pclntab_test.go
@@ -0,0 +1,407 @@
+// 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"
+	"compress/gzip"
+	"debug/elf"
+	"internal/testenv"
+	"io"
+	"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)
+	}
+	// This test builds a Linux/AMD64 binary. Skipping in short mode if cross compiling.
+	if runtime.GOOS != "linux" && testing.Short() {
+		t.Skipf("skipping in short mode on non-Linux system %s", runtime.GOARCH)
+	}
+	var err error
+	pclineTempDir, err = os.MkdirTemp("", "pclinetest")
+	if err != nil {
+		t.Fatal(err)
+	}
+	pclinetestBinary = filepath.Join(pclineTempDir, "pclinetest")
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", pclinetestBinary)
+	cmd.Dir = "testdata"
+	cmd.Env = append(os.Environ(), "GOOS=linux")
+	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", "illumos":
+		// 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("main.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.s") || line != wantLine || fn != sym {
+			t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.s", wantLine, sym.Name)
+		}
+	}
+
+	// Test LineToPC
+	sym = tab.LookupFunc("main.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
+	}
+}
+
+func TestSymVersion(t *testing.T) {
+	skipIfNotELF(t)
+
+	table := getTable(t)
+	if table.go12line == nil {
+		t.Skip("not relevant to Go 1.2+ symbol table")
+	}
+	for _, fn := range table.Funcs {
+		if fn.goVersion == verUnknown {
+			t.Fatalf("unexpected symbol version: %v", fn)
+		}
+	}
+}
+
+// read115Executable returns a hello world executable compiled by Go 1.15.
+//
+// The file was compiled in /tmp/hello.go:
+//
+//	package main
+//
+//	func main() {
+//		println("hello")
+//	}
+func read115Executable(tb testing.TB) []byte {
+	zippedDat, err := os.ReadFile("testdata/pcln115.gz")
+	if err != nil {
+		tb.Fatal(err)
+	}
+	var gzReader *gzip.Reader
+	gzReader, err = gzip.NewReader(bytes.NewBuffer(zippedDat))
+	if err != nil {
+		tb.Fatal(err)
+	}
+	var dat []byte
+	dat, err = io.ReadAll(gzReader)
+	if err != nil {
+		tb.Fatal(err)
+	}
+	return dat
+}
+
+// Test that we can parse a pclntab from 1.15.
+func Test115PclnParsing(t *testing.T) {
+	dat := read115Executable(t)
+	const textStart = 0x1001000
+	pcln := NewLineTable(dat, textStart)
+	tab, err := NewTable(nil, pcln)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var f *Func
+	var pc uint64
+	pc, f, err = tab.LineToPC("/tmp/hello.go", 3)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if pcln.version != ver12 {
+		t.Fatal("Expected pcln to parse as an older version")
+	}
+	if pc != 0x105c280 {
+		t.Fatalf("expect pc = 0x105c280, got 0x%x", pc)
+	}
+	if f.Name != "main.main" {
+		t.Fatalf("expected to parse name as main.main, got %v", f.Name)
+	}
+}
+
+var (
+	sinkLineTable *LineTable
+	sinkTable     *Table
+)
+
+func Benchmark115(b *testing.B) {
+	dat := read115Executable(b)
+	const textStart = 0x1001000
+
+	b.Run("NewLineTable", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			sinkLineTable = NewLineTable(dat, textStart)
+		}
+	})
+
+	pcln := NewLineTable(dat, textStart)
+	b.Run("NewTable", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			var err error
+			sinkTable, err = NewTable(nil, pcln)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+
+	tab, err := NewTable(nil, pcln)
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	b.Run("LineToPC", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			var f *Func
+			var pc uint64
+			pc, f, err = tab.LineToPC("/tmp/hello.go", 3)
+			if err != nil {
+				b.Fatal(err)
+			}
+			if pcln.version != ver12 {
+				b.Fatalf("want version=%d, got %d", ver12, pcln.version)
+			}
+			if pc != 0x105c280 {
+				b.Fatalf("want pc=0x105c280, got 0x%x", pc)
+			}
+			if f.Name != "main.main" {
+				b.Fatalf("want name=main.main, got %q", f.Name)
+			}
+		}
+	})
+
+	b.Run("PCToLine", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			file, line, fn := tab.PCToLine(0x105c280)
+			if file != "/tmp/hello.go" {
+				b.Fatalf("want name=/tmp/hello.go, got %q", file)
+			}
+			if line != 3 {
+				b.Fatalf("want line=3, got %d", line)
+			}
+			if fn.Name != "main.main" {
+				b.Fatalf("want name=main.main, got %q", fn.Name)
+			}
+		}
+	})
+}