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-rw-r--r--src/runtime/example_test.go54
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diff --git a/src/runtime/example_test.go b/src/runtime/example_test.go
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+// Copyright 2017 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.
+
+package runtime_test
+
+import (
+ "fmt"
+ "runtime"
+ "strings"
+)
+
+func ExampleFrames() {
+ c := func() {
+ // Ask runtime.Callers for up to 10 pcs, including runtime.Callers itself.
+ pc := make([]uintptr, 10)
+ n := runtime.Callers(0, pc)
+ if n == 0 {
+ // No pcs available. Stop now.
+ // This can happen if the first argument to runtime.Callers is large.
+ return
+ }
+
+ pc = pc[:n] // pass only valid pcs to runtime.CallersFrames
+ frames := runtime.CallersFrames(pc)
+
+ // Loop to get frames.
+ // A fixed number of pcs can expand to an indefinite number of Frames.
+ for {
+ frame, more := frames.Next()
+ // To keep this example's output stable
+ // even if there are changes in the testing package,
+ // stop unwinding when we leave package runtime.
+ if !strings.Contains(frame.File, "runtime/") {
+ break
+ }
+ fmt.Printf("- more:%v | %s\n", more, frame.Function)
+ if !more {
+ break
+ }
+ }
+ }
+
+ b := func() { c() }
+ a := func() { b() }
+
+ a()
+ // Output:
+ // - more:true | runtime.Callers
+ // - more:true | runtime_test.ExampleFrames.func1
+ // - more:true | runtime_test.ExampleFrames.func2
+ // - more:true | runtime_test.ExampleFrames.func3
+ // - more:true | runtime_test.ExampleFrames
+}