objfile_test.go

Documentation: cmd/internal/obj

     1  // Copyright 2020 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  package obj
     6  
     7  import (
     8  	"bytes"
     9  	"cmd/internal/goobj"
    10  	"cmd/internal/sys"
    11  	"internal/testenv"
    12  	"io/ioutil"
    13  	"os"
    14  	"os/exec"
    15  	"path/filepath"
    16  	"testing"
    17  	"unsafe"
    18  )
    19  
    20  var dummyArch = LinkArch{Arch: sys.ArchAMD64}
    21  
    22  func TestContentHash64(t *testing.T) {
    23  	s1 := &LSym{P: []byte("A")}
    24  	s2 := &LSym{P: []byte("A\x00\x00\x00")}
    25  	s1.Set(AttrContentAddressable, true)
    26  	s2.Set(AttrContentAddressable, true)
    27  	h1 := contentHash64(s1)
    28  	h2 := contentHash64(s2)
    29  	if h1 != h2 {
    30  		t.Errorf("contentHash64(s1)=%x, contentHash64(s2)=%x, expect equal", h1, h2)
    31  	}
    32  
    33  	ctxt := Linknew(&dummyArch) // little endian
    34  	s3 := ctxt.Int64Sym(int64('A'))
    35  	h3 := contentHash64(s3)
    36  	if h1 != h3 {
    37  		t.Errorf("contentHash64(s1)=%x, contentHash64(s3)=%x, expect equal", h1, h3)
    38  	}
    39  }
    40  
    41  func TestContentHash(t *testing.T) {
    42  	syms := []*LSym{
    43  		&LSym{P: []byte("TestSymbol")},  // 0
    44  		&LSym{P: []byte("TestSymbol")},  // 1
    45  		&LSym{P: []byte("TestSymbol2")}, // 2
    46  		&LSym{P: []byte("")},            // 3
    47  		&LSym{P: []byte("")},            // 4
    48  		&LSym{P: []byte("")},            // 5
    49  		&LSym{P: []byte("")},            // 6
    50  	}
    51  	for _, s := range syms {
    52  		s.Set(AttrContentAddressable, true)
    53  		s.PkgIdx = goobj.PkgIdxHashed
    54  	}
    55  	// s3 references s0
    56  	r := Addrel(syms[3])
    57  	r.Sym = syms[0]
    58  	// s4 references s0
    59  	r = Addrel(syms[4])
    60  	r.Sym = syms[0]
    61  	// s5 references s1
    62  	r = Addrel(syms[5])
    63  	r.Sym = syms[1]
    64  	// s6 references s2
    65  	r = Addrel(syms[6])
    66  	r.Sym = syms[2]
    67  
    68  	// compute hashes
    69  	h := make([]goobj.HashType, len(syms))
    70  	w := &writer{}
    71  	for i := range h {
    72  		h[i] = w.contentHash(syms[i])
    73  	}
    74  
    75  	tests := []struct {
    76  		a, b  int
    77  		equal bool
    78  	}{
    79  		{0, 1, true},  // same contents, no relocs
    80  		{0, 2, false}, // different contents
    81  		{3, 4, true},  // same contents, same relocs
    82  		{3, 5, true},  // recursively same contents
    83  		{3, 6, false}, // same contents, different relocs
    84  	}
    85  	for _, test := range tests {
    86  		if (h[test.a] == h[test.b]) != test.equal {
    87  			eq := "equal"
    88  			if !test.equal {
    89  				eq = "not equal"
    90  			}
    91  			t.Errorf("h%d=%x, h%d=%x, expect %s", test.a, h[test.a], test.b, h[test.b], eq)
    92  		}
    93  	}
    94  }
    95  
    96  func TestSymbolTooLarge(t *testing.T) { // Issue 42054
    97  	testenv.MustHaveGoBuild(t)
    98  	if unsafe.Sizeof(uintptr(0)) < 8 {
    99  		t.Skip("skip on 32-bit architectures")
   100  	}
   101  
   102  	tmpdir, err := ioutil.TempDir("", "TestSymbolTooLarge")
   103  	if err != nil {
   104  		t.Fatal(err)
   105  	}
   106  	defer os.RemoveAll(tmpdir)
   107  
   108  	src := filepath.Join(tmpdir, "p.go")
   109  	err = ioutil.WriteFile(src, []byte("package p; var x [1<<32]byte"), 0666)
   110  	if err != nil {
   111  		t.Fatalf("failed to write source file: %v\n", err)
   112  	}
   113  	obj := filepath.Join(tmpdir, "p.o")
   114  	cmd := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-o", obj, src)
   115  	out, err := cmd.CombinedOutput()
   116  	if err == nil {
   117  		t.Fatalf("did not fail\noutput: %s", out)
   118  	}
   119  	const want = "symbol too large"
   120  	if !bytes.Contains(out, []byte(want)) {
   121  		t.Errorf("unexpected error message: want: %q, got: %s", want, out)
   122  	}
   123  }
   124
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