deadcode_test.go

Documentation: cmd/link/internal/ld

     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 ld
     6  
     7  import (
     8  	"bytes"
     9  	"internal/testenv"
    10  	"os/exec"
    11  	"path/filepath"
    12  	"testing"
    13  )
    14  
    15  func TestDeadcode(t *testing.T) {
    16  	testenv.MustHaveGoBuild(t)
    17  	t.Parallel()
    18  
    19  	tmpdir := t.TempDir()
    20  
    21  	tests := []struct {
    22  		src      string
    23  		pos, neg string // positive and negative patterns
    24  	}{
    25  		{"reflectcall", "", "main.T.M"},
    26  		{"typedesc", "", "type.main.T"},
    27  		{"ifacemethod", "", "main.T.M"},
    28  		{"ifacemethod2", "main.T.M", ""},
    29  		{"ifacemethod3", "main.S.M", ""},
    30  		{"ifacemethod4", "", "main.T.M"},
    31  	}
    32  	for _, test := range tests {
    33  		test := test
    34  		t.Run(test.src, func(t *testing.T) {
    35  			t.Parallel()
    36  			src := filepath.Join("testdata", "deadcode", test.src+".go")
    37  			exe := filepath.Join(tmpdir, test.src+".exe")
    38  			cmd := exec.Command(testenv.GoToolPath(t), "build", "-ldflags=-dumpdep", "-o", exe, src)
    39  			out, err := cmd.CombinedOutput()
    40  			if err != nil {
    41  				t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
    42  			}
    43  			if test.pos != "" && !bytes.Contains(out, []byte(test.pos+"\n")) {
    44  				t.Errorf("%s should be reachable. Output:\n%s", test.pos, out)
    45  			}
    46  			if test.neg != "" && bytes.Contains(out, []byte(test.neg+"\n")) {
    47  				t.Errorf("%s should not be reachable. Output:\n%s", test.neg, out)
    48  			}
    49  		})
    50  	}
    51  }
    52
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