Bump version to 5.11.0

vendor/github.com/golang/glog/internal/stackdump/stackdump.go

@@ -0,0 +1,127 @@
+// Copyright 2023 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package stackdump provides wrappers for runtime.Stack and runtime.Callers
+// with uniform support for skipping caller frames.
+//
+// ⚠ Unlike the functions in the runtime package, these may allocate a
+// non-trivial quantity of memory: use them with care. ⚠
+package stackdump
+
+import (
+	"bytes"
+	"runtime"
+)
+
+// runtimeStackSelfFrames is 1 if runtime.Stack includes the call to
+// runtime.Stack itself or 0 if it does not.
+//
+// As of 2016-04-27, the gccgo compiler includes runtime.Stack but the gc
+// compiler does not.
+var runtimeStackSelfFrames = func() int {
+	for n := 1 << 10; n < 1<<20; n *= 2 {
+		buf := make([]byte, n)
+		n := runtime.Stack(buf, false)
+		if bytes.Contains(buf[:n], []byte("runtime.Stack")) {
+			return 1
+		} else if n < len(buf) || bytes.Count(buf, []byte("\n")) >= 3 {
+			return 0
+		}
+	}
+	return 0
+}()
+
+// Stack is a stack dump for a single goroutine.
+type Stack struct {
+	// Text is a representation of the stack dump in a human-readable format.
+	Text []byte
+
+	// PC is a representation of the stack dump using raw program counter values.
+	PC []uintptr
+}
+
+func (s Stack) String() string { return string(s.Text) }
+
+// Caller returns the Stack dump for the calling goroutine, starting skipDepth
+// frames before the caller of Caller.  (Caller(0) provides a dump starting at
+// the caller of this function.)
+func Caller(skipDepth int) Stack {
+	return Stack{
+		Text: CallerText(skipDepth + 1),
+		PC:   CallerPC(skipDepth + 1),
+	}
+}
+
+// CallerText returns a textual dump of the stack starting skipDepth frames before
+// the caller.  (CallerText(0) provides a dump starting at the caller of this
+// function.)
+func CallerText(skipDepth int) []byte {
+	for n := 1 << 10; ; n *= 2 {
+		buf := make([]byte, n)
+		n := runtime.Stack(buf, false)
+		if n < len(buf) {
+			return pruneFrames(skipDepth+1+runtimeStackSelfFrames, buf[:n])
+		}
+	}
+}
+
+// CallerPC returns a dump of the program counters of the stack starting
+// skipDepth frames before the caller.  (CallerPC(0) provides a dump starting at
+// the caller of this function.)
+func CallerPC(skipDepth int) []uintptr {
+	for n := 1 << 8; ; n *= 2 {
+		buf := make([]uintptr, n)
+		n := runtime.Callers(skipDepth+2, buf)
+		if n < len(buf) {
+			return buf[:n]
+		}
+	}
+}
+
+// pruneFrames removes the topmost skipDepth frames of the first goroutine in a
+// textual stack dump.  It overwrites the passed-in slice.
+//
+// If there are fewer than skipDepth frames in the first goroutine's stack,
+// pruneFrames prunes it to an empty stack and leaves the remaining contents
+// intact.
+func pruneFrames(skipDepth int, stack []byte) []byte {
+	headerLen := 0
+	for i, c := range stack {
+		if c == '\n' {
+			headerLen = i + 1
+			break
+		}
+	}
+	if headerLen == 0 {
+		return stack // No header line - not a well-formed stack trace.
+	}
+
+	skipLen := headerLen
+	skipNewlines := skipDepth * 2
+	for ; skipLen < len(stack) && skipNewlines > 0; skipLen++ {
+		c := stack[skipLen]
+		if c != '\n' {
+			continue
+		}
+		skipNewlines--
+		skipLen++
+		if skipNewlines == 0 || skipLen == len(stack) || stack[skipLen] == '\n' {
+			break
+		}
+	}
+
+	pruned := stack[skipLen-headerLen:]
+	copy(pruned, stack[:headerLen])
+	return pruned
+}