1 // Copyright 2017 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 "cmd/go/internal/base" 9 "fmt" 10 "io" 11 "os" 12 "path/filepath" 13 "sync" 14 ) 15 16 var coverMerge struct { 17 f *os.File 18 sync.Mutex // for f.Write 19 } 20 21 // initCoverProfile initializes the test coverage profile. 22 // It must be run before any calls to mergeCoverProfile or closeCoverProfile. 23 // Using this function clears the profile in case it existed from a previous run, 24 // or in case it doesn't exist and the test is going to fail to create it (or not run). 25 func initCoverProfile() { 26 if testCoverProfile == "" { 27 return 28 } 29 if !filepath.IsAbs(testCoverProfile) && testOutputDir != "" { 30 testCoverProfile = filepath.Join(testOutputDir, testCoverProfile) 31 } 32 33 // No mutex - caller's responsibility to call with no racing goroutines. 34 f, err := os.Create(testCoverProfile) 35 if err != nil { 36 base.Fatalf("%v", err) 37 } 38 _, err = fmt.Fprintf(f, "mode: %s\n", testCoverMode) 39 if err != nil { 40 base.Fatalf("%v", err) 41 } 42 coverMerge.f = f 43 } 44 45 // mergeCoverProfile merges file into the profile stored in testCoverProfile. 46 // It prints any errors it encounters to ew. 47 func mergeCoverProfile(ew io.Writer, file string) { 48 if coverMerge.f == nil { 49 return 50 } 51 coverMerge.Lock() 52 defer coverMerge.Unlock() 53 54 expect := fmt.Sprintf("mode: %s\n", testCoverMode) 55 buf := make([]byte, len(expect)) 56 r, err := os.Open(file) 57 if err != nil { 58 // Test did not create profile, which is OK. 59 return 60 } 61 defer r.Close() 62 63 n, err := io.ReadFull(r, buf) 64 if n == 0 { 65 return 66 } 67 if err != nil || string(buf) != expect { 68 fmt.Fprintf(ew, "error: test wrote malformed coverage profile.\n") 69 return 70 } 71 _, err = io.Copy(coverMerge.f, r) 72 if err != nil { 73 fmt.Fprintf(ew, "error: saving coverage profile: %v\n", err) 74 } 75 } 76 77 func closeCoverProfile() { 78 if coverMerge.f == nil { 79 return 80 } 81 if err := coverMerge.f.Close(); err != nil { 82 base.Errorf("closing coverage profile: %v", err) 83 } 84 } 85
