objfile_test.go

Documentation: cmd/internal/goobj

     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 goobj
     6  
     7  import (
     8  	"bufio"
     9  	"bytes"
    10  	"cmd/internal/bio"
    11  	"cmd/internal/objabi"
    12  	"fmt"
    13  	"internal/buildcfg"
    14  	"internal/testenv"
    15  	"io/ioutil"
    16  	"os"
    17  	"os/exec"
    18  	"testing"
    19  )
    20  
    21  func dummyWriter(buf *bytes.Buffer) *Writer {
    22  	wr := &bio.Writer{Writer: bufio.NewWriter(buf)} // hacky: no file, so cannot seek
    23  	return NewWriter(wr)
    24  }
    25  
    26  func TestReadWrite(t *testing.T) {
    27  	// Test that we get the same data in a write-read roundtrip.
    28  
    29  	// Write a symbol, a relocation, and an aux info.
    30  	var buf bytes.Buffer
    31  	w := dummyWriter(&buf)
    32  
    33  	var s Sym
    34  	s.SetABI(1)
    35  	s.SetType(uint8(objabi.STEXT))
    36  	s.SetFlag(0x12)
    37  	s.SetSiz(12345)
    38  	s.SetAlign(8)
    39  	s.Write(w)
    40  
    41  	var r Reloc
    42  	r.SetOff(12)
    43  	r.SetSiz(4)
    44  	r.SetType(uint16(objabi.R_ADDR))
    45  	r.SetAdd(54321)
    46  	r.SetSym(SymRef{11, 22})
    47  	r.Write(w)
    48  
    49  	var a Aux
    50  	a.SetType(AuxFuncInfo)
    51  	a.SetSym(SymRef{33, 44})
    52  	a.Write(w)
    53  
    54  	w.wr.Flush()
    55  
    56  	// Read them back and check.
    57  	b := buf.Bytes()
    58  	var s2 Sym
    59  	s2.fromBytes(b)
    60  	if s2.ABI() != 1 || s2.Type() != uint8(objabi.STEXT) || s2.Flag() != 0x12 || s2.Siz() != 12345 || s2.Align() != 8 {
    61  		t.Errorf("read Sym2 mismatch: got %v %v %v %v %v", s2.ABI(), s2.Type(), s2.Flag(), s2.Siz(), s2.Align())
    62  	}
    63  
    64  	b = b[SymSize:]
    65  	var r2 Reloc
    66  	r2.fromBytes(b)
    67  	if r2.Off() != 12 || r2.Siz() != 4 || r2.Type() != uint16(objabi.R_ADDR) || r2.Add() != 54321 || r2.Sym() != (SymRef{11, 22}) {
    68  		t.Errorf("read Reloc2 mismatch: got %v %v %v %v %v", r2.Off(), r2.Siz(), r2.Type(), r2.Add(), r2.Sym())
    69  	}
    70  
    71  	b = b[RelocSize:]
    72  	var a2 Aux
    73  	a2.fromBytes(b)
    74  	if a2.Type() != AuxFuncInfo || a2.Sym() != (SymRef{33, 44}) {
    75  		t.Errorf("read Aux2 mismatch: got %v %v", a2.Type(), a2.Sym())
    76  	}
    77  }
    78  
    79  var issue41621prolog = `
    80  package main
    81  var lines = []string{
    82  `
    83  
    84  var issue41621epilog = `
    85  }
    86  func getLines() []string {
    87  	return lines
    88  }
    89  func main() {
    90  	println(getLines())
    91  }
    92  `
    93  
    94  func TestIssue41621LargeNumberOfRelocations(t *testing.T) {
    95  	if testing.Short() || (buildcfg.GOARCH != "amd64") {
    96  		t.Skipf("Skipping large number of relocations test in short mode or on %s", buildcfg.GOARCH)
    97  	}
    98  	testenv.MustHaveGoBuild(t)
    99  
   100  	tmpdir, err := ioutil.TempDir("", "lotsofrelocs")
   101  	if err != nil {
   102  		t.Fatalf("can't create temp directory: %v\n", err)
   103  	}
   104  	defer os.RemoveAll(tmpdir)
   105  
   106  	// Emit testcase.
   107  	var w bytes.Buffer
   108  	fmt.Fprintf(&w, issue41621prolog)
   109  	for i := 0; i < 1048576+13; i++ {
   110  		fmt.Fprintf(&w, "\t\"%d\",\n", i)
   111  	}
   112  	fmt.Fprintf(&w, issue41621epilog)
   113  	err = ioutil.WriteFile(tmpdir+"/large.go", w.Bytes(), 0666)
   114  	if err != nil {
   115  		t.Fatalf("can't write output: %v\n", err)
   116  	}
   117  
   118  	// Emit go.mod
   119  	w.Reset()
   120  	fmt.Fprintf(&w, "module issue41621\n\ngo 1.12\n")
   121  	err = ioutil.WriteFile(tmpdir+"/go.mod", w.Bytes(), 0666)
   122  	if err != nil {
   123  		t.Fatalf("can't write output: %v\n", err)
   124  	}
   125  	w.Reset()
   126  
   127  	// Build.
   128  	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "large")
   129  	cmd.Dir = tmpdir
   130  	out, err := cmd.CombinedOutput()
   131  	if err != nil {
   132  		t.Fatalf("Build failed: %v, output: %s", err, out)
   133  	}
   134  }
   135
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