[dev.unified] all: merge master (85d87b9) into dev.unified

[gostls13.git] / src / internal / pkgbits / sync.go

diff --git a/src/internal/pkgbits/sync.go b/src/internal/pkgbits/sync.go
index a17a0088f759aee53b762707df9f99037e49a0ff..1520b73afb9e960c166c587981bc934017ecbb74 100644 (file)
--- a/src/internal/pkgbits/sync.go
+++ b/src/internal/pkgbits/sync.go
@@ -6,6 +6,7 @@ package pkgbits
 
 import (
        "fmt"
+       "runtime"
        "strings"
 )
 
@@ -23,6 +24,24 @@ func fmtFrames(pcs ...uintptr) []string {
 
 type frameVisitor func(file string, line int, name string, offset uintptr)
 
+// walkFrames calls visit for each call frame represented by pcs.
+//
+// pcs should be a slice of PCs, as returned by runtime.Callers.
+func walkFrames(pcs []uintptr, visit frameVisitor) {
+       if len(pcs) == 0 {
+               return
+       }
+
+       frames := runtime.CallersFrames(pcs)
+       for {
+               frame, more := frames.Next()
+               visit(frame.File, frame.Line, frame.Function, frame.PC-frame.Entry)
+               if !more {
+                       return
+               }
+       }
+}
+
 // SyncMarker is an enum type that represents markers that may be
 // written to export data to ensure the reader and writer stay
 // synchronized.