inst_test.go

     1  // Copyright 2021 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 test
     6  
     7  import (
     8  	"internal/testenv"
     9  	"os"
    10  	"path/filepath"
    11  	"regexp"
    12  	"testing"
    13  )
    14  
    15  // TestInst tests that only one instantiation of Sort is created, even though generic
    16  // Sort is used for multiple pointer types across two packages.
    17  func TestInst(t *testing.T) {
    18  	testenv.MustHaveGoBuild(t)
    19  	testenv.MustHaveGoRun(t)
    20  
    21  	// Build ptrsort.go, which uses package mysort.
    22  	var output []byte
    23  	var err error
    24  	filename := "ptrsort.go"
    25  	exename := "ptrsort"
    26  	outname := "ptrsort.out"
    27  	gotool := testenv.GoToolPath(t)
    28  	dest := filepath.Join(t.TempDir(), exename)
    29  	cmd := testenv.Command(t, gotool, "build", "-o", dest, filepath.Join("testdata", filename))
    30  	if output, err = cmd.CombinedOutput(); err != nil {
    31  		t.Fatalf("Failed: %v:\nOutput: %s\n", err, output)
    32  	}
    33  
    34  	// Test that there is exactly one shape-based instantiation of Sort in
    35  	// the executable.
    36  	cmd = testenv.Command(t, gotool, "tool", "nm", dest)
    37  	if output, err = cmd.CombinedOutput(); err != nil {
    38  		t.Fatalf("Failed: %v:\nOut: %s\n", err, output)
    39  	}
    40  	// Look for shape-based instantiation of Sort, but ignore any extra wrapper
    41  	// ending in "-tramp" (which are created on riscv).
    42  	re := regexp.MustCompile(`\bSort\[.*shape.*\][^-]`)
    43  	r := re.FindAllIndex(output, -1)
    44  	if len(r) != 1 {
    45  		t.Fatalf("Wanted 1 instantiations of Sort function, got %d\n", len(r))
    46  	}
    47  
    48  	// Actually run the test and make sure output is correct.
    49  	cmd = testenv.Command(t, gotool, "run", filepath.Join("testdata", filename))
    50  	if output, err = cmd.CombinedOutput(); err != nil {
    51  		t.Fatalf("Failed: %v:\nOut: %s\n", err, output)
    52  	}
    53  	out, err := os.ReadFile(filepath.Join("testdata", outname))
    54  	if err != nil {
    55  		t.Fatalf("Could not find %s\n", outname)
    56  	}
    57  	if string(out) != string(output) {
    58  		t.Fatalf("Wanted output %v, got %v\n", string(out), string(output))
    59  	}
    60  }
    61
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