diff options
Diffstat (limited to 'vendor/github.com/davecgh/go-spew/spew/bypass.go')
| -rw-r--r-- | vendor/github.com/davecgh/go-spew/spew/bypass.go | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/vendor/github.com/davecgh/go-spew/spew/bypass.go b/vendor/github.com/davecgh/go-spew/spew/bypass.go deleted file mode 100644 index 8a4a658..0000000 --- a/vendor/github.com/davecgh/go-spew/spew/bypass.go +++ /dev/null @@ -1,152 +0,0 @@ -// Copyright (c) 2015-2016 Dave Collins <dave@davec.name> -// -// 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, compiled by GopherJS, and -// "-tags safe" is not added to the go build command line. The "disableunsafe" -// tag is deprecated and thus should not be used. -// +build !js,!appengine,!safe,!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<<flagKindWidth - 1) << flagKindShift) - if (upfv&flagKindMask)>>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 -} |