objfile_test.go

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