435c0d9fc8
This PR switches the Nomad repository from using govendor to Go modules for managing dependencies. Aspects of the Nomad workflow remain pretty much the same. The usual Makefile targets should continue to work as they always did. The API submodule simply defers to the parent Nomad version on the repository, keeping the semantics of API versioning that currently exists.
57 lines
1.5 KiB
Go
57 lines
1.5 KiB
Go
// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package xerrors
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import (
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"runtime"
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)
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// A Frame contains part of a call stack.
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type Frame struct {
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// Make room for three PCs: the one we were asked for, what it called,
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// and possibly a PC for skipPleaseUseCallersFrames. See:
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// https://go.googlesource.com/go/+/032678e0fb/src/runtime/extern.go#169
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frames [3]uintptr
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}
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// Caller returns a Frame that describes a frame on the caller's stack.
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// The argument skip is the number of frames to skip over.
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// Caller(0) returns the frame for the caller of Caller.
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func Caller(skip int) Frame {
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var s Frame
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runtime.Callers(skip+1, s.frames[:])
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return s
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}
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// location reports the file, line, and function of a frame.
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//
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// The returned function may be "" even if file and line are not.
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func (f Frame) location() (function, file string, line int) {
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frames := runtime.CallersFrames(f.frames[:])
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if _, ok := frames.Next(); !ok {
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return "", "", 0
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}
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fr, ok := frames.Next()
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if !ok {
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return "", "", 0
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}
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return fr.Function, fr.File, fr.Line
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}
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// Format prints the stack as error detail.
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// It should be called from an error's Format implementation
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// after printing any other error detail.
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func (f Frame) Format(p Printer) {
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if p.Detail() {
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function, file, line := f.location()
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if function != "" {
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p.Printf("%s\n ", function)
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}
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if file != "" {
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p.Printf("%s:%d\n", file, line)
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}
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}
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}
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