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-rw-r--r--src/testing/cover.go121
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diff --git a/src/testing/cover.go b/src/testing/cover.go
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+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Support for test coverage.
+
+package testing
+
+import (
+ "fmt"
+ "internal/goexperiment"
+ "os"
+ "sync/atomic"
+)
+
+// CoverBlock records the coverage data for a single basic block.
+// The fields are 1-indexed, as in an editor: The opening line of
+// the file is number 1, for example. Columns are measured
+// in bytes.
+// NOTE: This struct is internal to the testing infrastructure and may change.
+// It is not covered (yet) by the Go 1 compatibility guidelines.
+type CoverBlock struct {
+ Line0 uint32 // Line number for block start.
+ Col0 uint16 // Column number for block start.
+ Line1 uint32 // Line number for block end.
+ Col1 uint16 // Column number for block end.
+ Stmts uint16 // Number of statements included in this block.
+}
+
+var cover Cover
+
+// Cover records information about test coverage checking.
+// NOTE: This struct is internal to the testing infrastructure and may change.
+// It is not covered (yet) by the Go 1 compatibility guidelines.
+type Cover struct {
+ Mode string
+ Counters map[string][]uint32
+ Blocks map[string][]CoverBlock
+ CoveredPackages string
+}
+
+// Coverage reports the current code coverage as a fraction in the range [0, 1].
+// If coverage is not enabled, Coverage returns 0.
+//
+// When running a large set of sequential test cases, checking Coverage after each one
+// can be useful for identifying which test cases exercise new code paths.
+// It is not a replacement for the reports generated by 'go test -cover' and
+// 'go tool cover'.
+func Coverage() float64 {
+ var n, d int64
+ for _, counters := range cover.Counters {
+ for i := range counters {
+ if atomic.LoadUint32(&counters[i]) > 0 {
+ n++
+ }
+ d++
+ }
+ }
+ if d == 0 {
+ return 0
+ }
+ return float64(n) / float64(d)
+}
+
+// RegisterCover records the coverage data accumulators for the tests.
+// NOTE: This function is internal to the testing infrastructure and may change.
+// It is not covered (yet) by the Go 1 compatibility guidelines.
+func RegisterCover(c Cover) {
+ cover = c
+}
+
+// mustBeNil checks the error and, if present, reports it and exits.
+func mustBeNil(err error) {
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "testing: %s\n", err)
+ os.Exit(2)
+ }
+}
+
+// coverReport reports the coverage percentage and writes a coverage profile if requested.
+func coverReport() {
+ if goexperiment.CoverageRedesign {
+ coverReport2()
+ return
+ }
+ var f *os.File
+ var err error
+ if *coverProfile != "" {
+ f, err = os.Create(toOutputDir(*coverProfile))
+ mustBeNil(err)
+ fmt.Fprintf(f, "mode: %s\n", cover.Mode)
+ defer func() { mustBeNil(f.Close()) }()
+ }
+
+ var active, total int64
+ var count uint32
+ for name, counts := range cover.Counters {
+ blocks := cover.Blocks[name]
+ for i := range counts {
+ stmts := int64(blocks[i].Stmts)
+ total += stmts
+ count = atomic.LoadUint32(&counts[i]) // For -mode=atomic.
+ if count > 0 {
+ active += stmts
+ }
+ if f != nil {
+ _, err := fmt.Fprintf(f, "%s:%d.%d,%d.%d %d %d\n", name,
+ blocks[i].Line0, blocks[i].Col0,
+ blocks[i].Line1, blocks[i].Col1,
+ stmts,
+ count)
+ mustBeNil(err)
+ }
+ }
+ }
+ if total == 0 {
+ fmt.Println("coverage: [no statements]")
+ return
+ }
+ fmt.Printf("coverage: %.1f%% of statements%s\n", 100*float64(active)/float64(total), cover.CoveredPackages)
+}