package debug
import (
- "bytes"
- "fmt"
- "io/ioutil"
"os"
"runtime"
)
-var (
- dunno = []byte("???")
- centerDot = []byte("·")
- dot = []byte(".")
- slash = []byte("/")
-)
-
-// PrintStack prints to standard error the stack trace returned by Stack.
+// PrintStack prints to standard error the stack trace returned by runtime.Stack.
func PrintStack() {
- os.Stderr.Write(stack())
+ os.Stderr.Write(Stack())
}
// Stack returns a formatted stack trace of the goroutine that calls it.
-// For each routine, it includes the source line information and PC value,
-// then attempts to discover, for Go functions, the calling function or
-// method and the text of the line containing the invocation.
-//
-// Deprecated: Use package runtime's Stack instead.
+// It calls [runtime.Stack] with a large enough buffer to capture the entire trace.
func Stack() []byte {
- return stack()
-}
-
-// stack implements Stack, skipping 2 frames
-func stack() []byte {
- buf := new(bytes.Buffer) // the returned data
- // As we loop, we open files and read them. These variables record the currently
- // loaded file.
- var lines [][]byte
- var lastFile string
- for i := 2; ; i++ { // Caller we care about is the user, 2 frames up
- pc, file, line, ok := runtime.Caller(i)
- if !ok {
- break
+ buf := make([]byte, 1024)
+ for {
+ n := runtime.Stack(buf, false)
+ if n < len(buf) {
+ return buf[:n]
}
- // Print this much at least. If we can't find the source, it won't show.
- fmt.Fprintf(buf, "%s:%d (0x%x)\n", file, line, pc)
- if file != lastFile {
- data, err := ioutil.ReadFile(file)
- if err != nil {
- continue
- }
- lines = bytes.Split(data, []byte{'\n'})
- lastFile = file
- }
- line-- // in stack trace, lines are 1-indexed but our array is 0-indexed
- fmt.Fprintf(buf, "\t%s: %s\n", function(pc), source(lines, line))
- }
- return buf.Bytes()
-}
-
-// source returns a space-trimmed slice of the n'th line.
-func source(lines [][]byte, n int) []byte {
- if n < 0 || n >= len(lines) {
- return dunno
- }
- return bytes.Trim(lines[n], " \t")
-}
-
-// function returns, if possible, the name of the function containing the PC.
-func function(pc uintptr) []byte {
- fn := runtime.FuncForPC(pc)
- if fn == nil {
- return dunno
- }
- name := []byte(fn.Name())
- // The name includes the path name to the package, which is unnecessary
- // since the file name is already included. Plus, it has center dots.
- // That is, we see
- // runtime/debug.*T·ptrmethod
- // and want
- // *T.ptrmethod
- // Since the package path might contains dots (e.g. code.google.com/...),
- // we first remove the path prefix if there is one.
- if lastslash := bytes.LastIndex(name, slash); lastslash >= 0 {
- name = name[lastslash+1:]
- }
- if period := bytes.Index(name, dot); period >= 0 {
- name = name[period+1:]
+ buf = make([]byte, 2*len(buf))
}
- name = bytes.Replace(name, centerDot, dot, -1)
- return name
}