runtime: make Frames example produce documented output

I believe now this code can work in both test and standalone situations.

Fixes #70057

Change-Id: Ieb5163e6b917fd03d050f65589df6c31ad2515fe
GitHub-Last-Rev: db4863c05e4d4bcbd40caf459d29e2eee81f847b
GitHub-Pull-Request: golang/go#70270
Reviewed-on: https://go-review.googlesource.com/c/go/+/625904
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Bypass: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/src/runtime/example_test.go b/src/runtime/example_test.go
index dcb8f7798e290581eab6858bbcb348966b0cd810..eae9dbd7bffecf2e8ae95f3f7095b176b9e49c6e 100644 (file)
--- a/src/runtime/example_test.go
+++ b/src/runtime/example_test.go
@@ -32,15 +32,14 @@ func ExampleFrames() {
                for {
                        frame, more := frames.Next()
 
-                       // Process this frame.
-                       //
-                       // 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/") {
+                       // Canonicalize function name and skip callers of this function
+                       // for predictable example output.
+                       // You probably don't need this in your own code.
+                       function := strings.ReplaceAll(frame.Function, "main.main", "runtime_test.ExampleFrames")
+                       fmt.Printf("- more:%v | %s\n", more, function)
+                       if function == "runtime_test.ExampleFrames" {
                                break
                        }
-                       fmt.Printf("- more:%v | %s\n", more, frame.Function)
 
                        // Check whether there are more frames to process after this one.
                        if !more {