+++ /dev/null
-package errors
-
-import (
- "fmt"
- "io"
- "path"
- "runtime"
- "strings"
-)
-
-// Frame represents a program counter inside a stack frame.
-type Frame uintptr
-
-// pc returns the program counter for this frame;
-// multiple frames may have the same PC value.
-func (f Frame) pc() uintptr { return uintptr(f) - 1 }
-
-// file returns the full path to the file that contains the
-// function for this Frame's pc.
-func (f Frame) file() string {
- fn := runtime.FuncForPC(f.pc())
- if fn == nil {
- return "unknown"
- }
- file, _ := fn.FileLine(f.pc())
- return file
-}
-
-// line returns the line number of source code of the
-// function for this Frame's pc.
-func (f Frame) line() int {
- fn := runtime.FuncForPC(f.pc())
- if fn == nil {
- return 0
- }
- _, line := fn.FileLine(f.pc())
- return line
-}
-
-// Format formats the frame according to the fmt.Formatter interface.
-//
-// %s source file
-// %d source line
-// %n function name
-// %v equivalent to %s:%d
-//
-// Format accepts flags that alter the printing of some verbs, as follows:
-//
-// %+s path of source file relative to the compile time GOPATH
-// %+v equivalent to %+s:%d
-func (f Frame) Format(s fmt.State, verb rune) {
- switch verb {
- case 's':
- switch {
- case s.Flag('+'):
- pc := f.pc()
- fn := runtime.FuncForPC(pc)
- if fn == nil {
- io.WriteString(s, "unknown")
- } else {
- file, _ := fn.FileLine(pc)
- fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
- }
- default:
- io.WriteString(s, path.Base(f.file()))
- }
- case 'd':
- fmt.Fprintf(s, "%d", f.line())
- case 'n':
- name := runtime.FuncForPC(f.pc()).Name()
- io.WriteString(s, funcname(name))
- case 'v':
- f.Format(s, 's')
- io.WriteString(s, ":")
- f.Format(s, 'd')
- }
-}
-
-// StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
-type StackTrace []Frame
-
-// Format formats the stack of Frames according to the fmt.Formatter interface.
-//
-// %s lists source files for each Frame in the stack
-// %v lists the source file and line number for each Frame in the stack
-//
-// Format accepts flags that alter the printing of some verbs, as follows:
-//
-// %+v Prints filename, function, and line number for each Frame in the stack.
-func (st StackTrace) Format(s fmt.State, verb rune) {
- switch verb {
- case 'v':
- switch {
- case s.Flag('+'):
- for _, f := range st {
- fmt.Fprintf(s, "\n%+v", f)
- }
- case s.Flag('#'):
- fmt.Fprintf(s, "%#v", []Frame(st))
- default:
- fmt.Fprintf(s, "%v", []Frame(st))
- }
- case 's':
- fmt.Fprintf(s, "%s", []Frame(st))
- }
-}
-
-// stack represents a stack of program counters.
-type stack []uintptr
-
-func (s *stack) Format(st fmt.State, verb rune) {
- switch verb {
- case 'v':
- switch {
- case st.Flag('+'):
- for _, pc := range *s {
- f := Frame(pc)
- fmt.Fprintf(st, "\n%+v", f)
- }
- }
- }
-}
-
-func (s *stack) StackTrace() StackTrace {
- f := make([]Frame, len(*s))
- for i := 0; i < len(f); i++ {
- f[i] = Frame((*s)[i])
- }
- return f
-}
-
-func callers() *stack {
- const depth = 32
- var pcs [depth]uintptr
- n := runtime.Callers(3, pcs[:])
- var st stack = pcs[0:n]
- return &st
-}
-
-// funcname removes the path prefix component of a function's name reported by func.Name().
-func funcname(name string) string {
- i := strings.LastIndex(name, "/")
- name = name[i+1:]
- i = strings.Index(name, ".")
- return name[i+1:]
-}
-
-func trimGOPATH(name, file string) string {
- // Here we want to get the source file path relative to the compile time
- // GOPATH. As of Go 1.6.x there is no direct way to know the compiled
- // GOPATH at runtime, but we can infer the number of path segments in the
- // GOPATH. We note that fn.Name() returns the function name qualified by
- // the import path, which does not include the GOPATH. Thus we can trim
- // segments from the beginning of the file path until the number of path
- // separators remaining is one more than the number of path separators in
- // the function name. For example, given:
- //
- // GOPATH /home/user
- // file /home/user/src/pkg/sub/file.go
- // fn.Name() pkg/sub.Type.Method
- //
- // We want to produce:
- //
- // pkg/sub/file.go
- //
- // From this we can easily see that fn.Name() has one less path separator
- // than our desired output. We count separators from the end of the file
- // path until it finds two more than in the function name and then move
- // one character forward to preserve the initial path segment without a
- // leading separator.
- const sep = "/"
- goal := strings.Count(name, sep) + 2
- i := len(file)
- for n := 0; n < goal; n++ {
- i = strings.LastIndex(file[:i], sep)
- if i == -1 {
- // not enough separators found, set i so that the slice expression
- // below leaves file unmodified
- i = -len(sep)
- break
- }
- }
- // get back to 0 or trim the leading separator
- file = file[i+len(sep):]
- return file
-}
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