From 649bf79117e30895108b7782d62daafd07bc5e6e Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 22 May 2016 01:23:33 +0100 Subject: Use govendor --- vendor/github.com/davecgh/go-spew/spew/bypass.go | 151 +++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 vendor/github.com/davecgh/go-spew/spew/bypass.go (limited to 'vendor/github.com/davecgh/go-spew/spew/bypass.go') diff --git a/vendor/github.com/davecgh/go-spew/spew/bypass.go b/vendor/github.com/davecgh/go-spew/spew/bypass.go new file mode 100644 index 0000000..565bf58 --- /dev/null +++ b/vendor/github.com/davecgh/go-spew/spew/bypass.go @@ -0,0 +1,151 @@ +// Copyright (c) 2015 Dave Collins +// +// Permission to use, copy, modify, and distribute this software for any +// purpose with or without fee is hereby granted, provided that the above +// copyright notice and this permission notice appear in all copies. +// +// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +// NOTE: Due to the following build constraints, this file will only be compiled +// when the code is not running on Google App Engine and "-tags disableunsafe" +// is not added to the go build command line. +// +build !appengine,!disableunsafe + +package spew + +import ( + "reflect" + "unsafe" +) + +const ( + // UnsafeDisabled is a build-time constant which specifies whether or + // not access to the unsafe package is available. + UnsafeDisabled = false + + // ptrSize is the size of a pointer on the current arch. + ptrSize = unsafe.Sizeof((*byte)(nil)) +) + +var ( + // offsetPtr, offsetScalar, and offsetFlag are the offsets for the + // internal reflect.Value fields. These values are valid before golang + // commit ecccf07e7f9d which changed the format. The are also valid + // after commit 82f48826c6c7 which changed the format again to mirror + // the original format. Code in the init function updates these offsets + // as necessary. + offsetPtr = uintptr(ptrSize) + offsetScalar = uintptr(0) + offsetFlag = uintptr(ptrSize * 2) + + // flagKindWidth and flagKindShift indicate various bits that the + // reflect package uses internally to track kind information. + // + // flagRO indicates whether or not the value field of a reflect.Value is + // read-only. + // + // flagIndir indicates whether the value field of a reflect.Value is + // the actual data or a pointer to the data. + // + // These values are valid before golang commit 90a7c3c86944 which + // changed their positions. Code in the init function updates these + // flags as necessary. + flagKindWidth = uintptr(5) + flagKindShift = uintptr(flagKindWidth - 1) + flagRO = uintptr(1 << 0) + flagIndir = uintptr(1 << 1) +) + +func init() { + // Older versions of reflect.Value stored small integers directly in the + // ptr field (which is named val in the older versions). Versions + // between commits ecccf07e7f9d and 82f48826c6c7 added a new field named + // scalar for this purpose which unfortunately came before the flag + // field, so the offset of the flag field is different for those + // versions. + // + // This code constructs a new reflect.Value from a known small integer + // and checks if the size of the reflect.Value struct indicates it has + // the scalar field. When it does, the offsets are updated accordingly. + vv := reflect.ValueOf(0xf00) + if unsafe.Sizeof(vv) == (ptrSize * 4) { + offsetScalar = ptrSize * 2 + offsetFlag = ptrSize * 3 + } + + // Commit 90a7c3c86944 changed the flag positions such that the low + // order bits are the kind. This code extracts the kind from the flags + // field and ensures it's the correct type. When it's not, the flag + // order has been changed to the newer format, so the flags are updated + // accordingly. + upf := unsafe.Pointer(uintptr(unsafe.Pointer(&vv)) + offsetFlag) + upfv := *(*uintptr)(upf) + flagKindMask := uintptr((1<>flagKindShift != uintptr(reflect.Int) { + flagKindShift = 0 + flagRO = 1 << 5 + flagIndir = 1 << 6 + + // Commit adf9b30e5594 modified the flags to separate the + // flagRO flag into two bits which specifies whether or not the + // field is embedded. This causes flagIndir to move over a bit + // and means that flagRO is the combination of either of the + // original flagRO bit and the new bit. + // + // This code detects the change by extracting what used to be + // the indirect bit to ensure it's set. When it's not, the flag + // order has been changed to the newer format, so the flags are + // updated accordingly. + if upfv&flagIndir == 0 { + flagRO = 3 << 5 + flagIndir = 1 << 7 + } + } +} + +// unsafeReflectValue converts the passed reflect.Value into a one that bypasses +// the typical safety restrictions preventing access to unaddressable and +// unexported data. It works by digging the raw pointer to the underlying +// value out of the protected value and generating a new unprotected (unsafe) +// reflect.Value to it. +// +// This allows us to check for implementations of the Stringer and error +// interfaces to be used for pretty printing ordinarily unaddressable and +// inaccessible values such as unexported struct fields. +func unsafeReflectValue(v reflect.Value) (rv reflect.Value) { + indirects := 1 + vt := v.Type() + upv := unsafe.Pointer(uintptr(unsafe.Pointer(&v)) + offsetPtr) + rvf := *(*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&v)) + offsetFlag)) + if rvf&flagIndir != 0 { + vt = reflect.PtrTo(v.Type()) + indirects++ + } else if offsetScalar != 0 { + // The value is in the scalar field when it's not one of the + // reference types. + switch vt.Kind() { + case reflect.Uintptr: + case reflect.Chan: + case reflect.Func: + case reflect.Map: + case reflect.Ptr: + case reflect.UnsafePointer: + default: + upv = unsafe.Pointer(uintptr(unsafe.Pointer(&v)) + + offsetScalar) + } + } + + pv := reflect.NewAt(vt, upv) + rv = pv + for i := 0; i < indirects; i++ { + rv = rv.Elem() + } + return rv +} -- cgit v1.2.3