mirror of
https://github.com/golang/go
synced 2024-10-01 09:48:32 -06:00
3b5de067a1
Core:
reflect.TypeOf
reflect.ValueOf
reflect.Zero
reflect.Value.Interface
Maps:
(reflect.Value).MapIndex
(reflect.Value).MapKeys
(reflect.Value).SetMapIndex
(*reflect.rtype).Elem
(*reflect.rtype).Key
+ tests:
pointer/testdata/mapreflect.go.
oracle/testdata/src/main/reflection.go.
Interface objects (T, V...) have been renamed "tagged objects".
Abstraction: we model reflect.Value similar to
interface{}---as a pointer that points only to tagged
objects---but a reflect.Value may also point to an "indirect
tagged object", one in which the payload V is of type *T not T.
These are required because reflect.Values can hold lvalues,
e.g. when derived via Field() or Elem(), though we won't use
them till we get to structs and pointers.
Solving: each reflection intrinsic defines a new constraint
and resolution rule. Because of the nature of reflection,
generalizing across types, the resolution rules dynamically
create additional complex constraints during solving, where
previously only simple (copy) constraints were created.
This requires some solver changes:
The work done before the main solver loop (to attach new
constraints to the graph) is now done before each iteration,
in processNewConstraints.
Its loop over constraints is broken into two passes:
the first handles base (addr-of) constraints,
the second handles simple and complex constraints.
constraint.init() has been inlined. The only behaviour that
varies across constraints is ptr()
Sadly this will pessimize presolver optimisations, when we get
there; such is the price of reflection.
Objects: reflection intrinsics create objects (i.e. cause
memory allocations) with no SSA operation. We will represent
them as the cgnode of the instrinsic (e.g. reflect.New), so we
extend Labels and node.data to represent objects as a product
(not sum) of ssa.Value and cgnode and pull this out into its
own type, struct object. This simplifies a number of
invariants and saves space. The ntObject flag is now
represented by obj!=nil; the other flags are moved into
object.
cgnodes are now always recorded in objects/Labels for which it
is appropriate (all but those for globals, constants and the
shared contours for functions).
Also:
- Prepopulate the flattenMemo cache to consider reflect.Value
a fake pointer, not a struct.
- Improve accessors and documentation on type Label.
- @conctypes assertions renamed @types (since dyn. types needn't be concrete).
- add oracle 'describe' test on an interface (missing, an oversight).
R=crawshaw
CC=golang-dev
https://golang.org/cl/13418048
308 lines
15 KiB
Go
308 lines
15 KiB
Go
// Copyright 2013 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 pointer
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// This package defines the treatment of intrinsics, i.e. library
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// functions requiring special analytical treatment.
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//
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// Most of these are C or assembly functions, but even some Go
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// functions require may special treatment if the analysis completely
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// replaces the implementation of an API such as reflection.
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// TODO(adonovan): support a means of writing analytic summaries in
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// the target code, so that users can summarise the effects of their
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// own C functions using a snippet of Go.
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import (
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"code.google.com/p/go.tools/ssa"
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)
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// Instances of 'intrinsic' generate analysis constraints for calls to
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// intrinsic functions.
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type intrinsic func(a *analysis, cgn *cgnode)
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// Initialized in explicit init() to defeat (spurious) initialization
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// cycle error.
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var intrinsicsByName map[string]intrinsic
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func init() {
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// Key strings are from Function.String().
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// That little dot ۰ is an Arabic zero numeral (U+06F0),
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// categories [Nd].
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intrinsicsByName = map[string]intrinsic{
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// reflect.Value methods.
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"(reflect.Value).Addr": ext۰reflect۰Value۰Addr,
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"(reflect.Value).Bool": ext۰NoEffect,
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"(reflect.Value).Bytes": ext۰reflect۰Value۰Bytes,
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"(reflect.Value).Call": ext۰reflect۰Value۰Call,
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"(reflect.Value).CallSlice": ext۰reflect۰Value۰CallSlice,
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"(reflect.Value).CanAddr": ext۰NoEffect,
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"(reflect.Value).CanInterface": ext۰NoEffect,
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"(reflect.Value).CanSet": ext۰NoEffect,
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"(reflect.Value).Cap": ext۰NoEffect,
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"(reflect.Value).Close": ext۰NoEffect,
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"(reflect.Value).Complex": ext۰NoEffect,
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"(reflect.Value).Convert": ext۰reflect۰Value۰Convert,
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"(reflect.Value).Elem": ext۰reflect۰Value۰Elem,
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"(reflect.Value).Field": ext۰reflect۰Value۰Field,
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"(reflect.Value).FieldByIndex": ext۰reflect۰Value۰FieldByIndex,
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"(reflect.Value).FieldByName": ext۰reflect۰Value۰FieldByName,
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"(reflect.Value).FieldByNameFunc": ext۰reflect۰Value۰FieldByNameFunc,
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"(reflect.Value).Float": ext۰NoEffect,
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"(reflect.Value).Index": ext۰reflect۰Value۰Index,
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"(reflect.Value).Int": ext۰NoEffect,
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"(reflect.Value).Interface": ext۰reflect۰Value۰Interface,
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"(reflect.Value).InterfaceData": ext۰NoEffect,
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"(reflect.Value).IsNil": ext۰NoEffect,
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"(reflect.Value).IsValid": ext۰NoEffect,
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"(reflect.Value).Kind": ext۰NoEffect,
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"(reflect.Value).Len": ext۰NoEffect,
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"(reflect.Value).MapIndex": ext۰reflect۰Value۰MapIndex,
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"(reflect.Value).MapKeys": ext۰reflect۰Value۰MapKeys,
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"(reflect.Value).Method": ext۰reflect۰Value۰Method,
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"(reflect.Value).MethodByName": ext۰reflect۰Value۰MethodByName,
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"(reflect.Value).NumField": ext۰NoEffect,
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"(reflect.Value).NumMethod": ext۰NoEffect,
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"(reflect.Value).OverflowComplex": ext۰NoEffect,
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"(reflect.Value).OverflowFloat": ext۰NoEffect,
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"(reflect.Value).OverflowInt": ext۰NoEffect,
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"(reflect.Value).OverflowUint": ext۰NoEffect,
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"(reflect.Value).Pointer": ext۰NoEffect,
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"(reflect.Value).Set": ext۰reflect۰Value۰Set,
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"(reflect.Value).SetBool": ext۰NoEffect,
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"(reflect.Value).SetBytes": ext۰reflect۰Value۰SetBytes,
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"(reflect.Value).SetComplex": ext۰NoEffect,
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"(reflect.Value).SetFloat": ext۰NoEffect,
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"(reflect.Value).SetInt": ext۰NoEffect,
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"(reflect.Value).SetLen": ext۰NoEffect,
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"(reflect.Value).SetMapIndex": ext۰reflect۰Value۰SetMapIndex,
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"(reflect.Value).SetPointer": ext۰reflect۰Value۰SetPointer,
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"(reflect.Value).SetString": ext۰NoEffect,
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"(reflect.Value).SetUint": ext۰NoEffect,
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"(reflect.Value).Slice": ext۰reflect۰Value۰Slice,
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"(reflect.Value).String": ext۰NoEffect,
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"(reflect.Value).Type": ext۰NoEffect,
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"(reflect.Value).Uint": ext۰NoEffect,
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"(reflect.Value).UnsafeAddr": ext۰NoEffect,
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// Standalone reflect.* functions.
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"reflect.Append": ext۰reflect۰Append,
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"reflect.AppendSlice": ext۰reflect۰AppendSlice,
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"reflect.Copy": ext۰reflect۰Copy,
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"reflect.ChanOf": ext۰reflect۰ChanOf,
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"reflect.DeepEqual": ext۰NoEffect,
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"reflect.Indirect": ext۰reflect۰Indirect,
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"reflect.MakeChan": ext۰reflect۰MakeChan,
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"reflect.MakeFunc": ext۰reflect۰MakeFunc,
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"reflect.MakeMap": ext۰reflect۰MakeMap,
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"reflect.MakeSlice": ext۰reflect۰MakeSlice,
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"reflect.MapOf": ext۰reflect۰MapOf,
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"reflect.New": ext۰reflect۰New,
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"reflect.NewAt": ext۰reflect۰NewAt,
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"reflect.PtrTo": ext۰reflect۰PtrTo,
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"reflect.Select": ext۰reflect۰Select,
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"reflect.SliceOf": ext۰reflect۰SliceOf,
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"reflect.TypeOf": ext۰reflect۰TypeOf,
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"reflect.ValueOf": ext۰reflect۰ValueOf,
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"reflect.Zero": ext۰reflect۰Zero,
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"reflect.init": ext۰NoEffect,
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// *reflect.rtype methods
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"(*reflect.rtype).Align": ext۰NoEffect,
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"(*reflect.rtype).AssignableTo": ext۰NoEffect,
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"(*reflect.rtype).Bits": ext۰NoEffect,
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"(*reflect.rtype).ChanDir": ext۰NoEffect,
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"(*reflect.rtype).ConvertibleTo": ext۰NoEffect,
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"(*reflect.rtype).Elem": ext۰reflect۰rtype۰Elem,
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"(*reflect.rtype).Field": ext۰reflect۰rtype۰Field,
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"(*reflect.rtype).FieldAlign": ext۰NoEffect,
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"(*reflect.rtype).FieldByIndex": ext۰reflect۰rtype۰FieldByIndex,
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"(*reflect.rtype).FieldByName": ext۰reflect۰rtype۰FieldByName,
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"(*reflect.rtype).FieldByNameFunc": ext۰reflect۰rtype۰FieldByNameFunc,
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"(*reflect.rtype).Implements": ext۰NoEffect,
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"(*reflect.rtype).In": ext۰reflect۰rtype۰In,
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"(*reflect.rtype).IsVariadic": ext۰NoEffect,
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"(*reflect.rtype).Key": ext۰reflect۰rtype۰Key,
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"(*reflect.rtype).Kind": ext۰NoEffect,
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"(*reflect.rtype).Len": ext۰NoEffect,
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"(*reflect.rtype).Method": ext۰reflect۰rtype۰Method,
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"(*reflect.rtype).MethodByName": ext۰reflect۰rtype۰MethodByName,
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"(*reflect.rtype).Name": ext۰NoEffect,
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"(*reflect.rtype).NumField": ext۰NoEffect,
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"(*reflect.rtype).NumIn": ext۰NoEffect,
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"(*reflect.rtype).NumMethod": ext۰NoEffect,
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"(*reflect.rtype).NumOut": ext۰NoEffect,
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"(*reflect.rtype).Out": ext۰reflect۰rtype۰Out,
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"(*reflect.rtype).PkgPath": ext۰NoEffect,
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"(*reflect.rtype).Size": ext۰NoEffect,
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"(*reflect.rtype).String": ext۰NoEffect,
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// Other packages.
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"bytes.Equal": ext۰NoEffect,
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"bytes.IndexByte": ext۰NoEffect,
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"crypto/aes.decryptBlockAsm": ext۰NoEffect,
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"crypto/aes.encryptBlockAsm": ext۰NoEffect,
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"crypto/aes.expandKeyAsm": ext۰NoEffect,
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"crypto/aes.hasAsm": ext۰NoEffect,
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"crypto/md5.block": ext۰NoEffect,
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"crypto/rc4.xorKeyStream": ext۰NoEffect,
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"crypto/sha1.block": ext۰NoEffect,
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"hash/crc32.castagnoliSSE42": ext۰NoEffect,
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"hash/crc32.haveSSE42": ext۰NoEffect,
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"math.Abs": ext۰NoEffect,
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"math.Acos": ext۰NoEffect,
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"math.Asin": ext۰NoEffect,
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"math.Atan": ext۰NoEffect,
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"math.Atan2": ext۰NoEffect,
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"math.Ceil": ext۰NoEffect,
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"math.Cos": ext۰NoEffect,
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"math.Dim": ext۰NoEffect,
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"math.Exp": ext۰NoEffect,
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"math.Exp2": ext۰NoEffect,
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"math.Expm1": ext۰NoEffect,
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"math.Float32bits": ext۰NoEffect,
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"math.Float32frombits": ext۰NoEffect,
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"math.Float64bits": ext۰NoEffect,
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"math.Float64frombits": ext۰NoEffect,
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"math.Floor": ext۰NoEffect,
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"math.Frexp": ext۰NoEffect,
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"math.Hypot": ext۰NoEffect,
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"math.Ldexp": ext۰NoEffect,
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"math.Log": ext۰NoEffect,
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"math.Log10": ext۰NoEffect,
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"math.Log1p": ext۰NoEffect,
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"math.Log2": ext۰NoEffect,
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"math.Max": ext۰NoEffect,
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"math.Min": ext۰NoEffect,
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"math.Mod": ext۰NoEffect,
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"math.Modf": ext۰NoEffect,
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"math.Remainder": ext۰NoEffect,
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"math.Sin": ext۰NoEffect,
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"math.Sincos": ext۰NoEffect,
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"math.Sqrt": ext۰NoEffect,
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"math.Tan": ext۰NoEffect,
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"math.Trunc": ext۰NoEffect,
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"math/big.addMulVVW": ext۰NoEffect,
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"math/big.addVV": ext۰NoEffect,
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"math/big.addVW": ext۰NoEffect,
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"math/big.bitLen": ext۰NoEffect,
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"math/big.divWVW": ext۰NoEffect,
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"math/big.divWW": ext۰NoEffect,
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"math/big.mulAddVWW": ext۰NoEffect,
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"math/big.mulWW": ext۰NoEffect,
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"math/big.shlVU": ext۰NoEffect,
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"math/big.shrVU": ext۰NoEffect,
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"math/big.subVV": ext۰NoEffect,
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"math/big.subVW": ext۰NoEffect,
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"net.runtime_Semacquire": ext۰NoEffect,
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"net.runtime_Semrelease": ext۰NoEffect,
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"net.runtime_pollClose": ext۰NoEffect,
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"net.runtime_pollOpen": ext۰NoEffect,
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"net.runtime_pollReset": ext۰NoEffect,
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"net.runtime_pollServerInit": ext۰NoEffect,
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"net.runtime_pollSetDeadline": ext۰NoEffect,
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"net.runtime_pollUnblock": ext۰NoEffect,
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"net.runtime_pollWait": ext۰NoEffect,
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"os.epipecheck": ext۰NoEffect,
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"runtime.BlockProfile": ext۰NoEffect,
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"runtime.Breakpoint": ext۰NoEffect,
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"runtime.CPUProfile": ext۰NotYetImplemented,
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"runtime.Caller": ext۰NoEffect,
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"runtime.FuncForPC": ext۰NotYetImplemented,
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"runtime.GC": ext۰NoEffect,
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"runtime.GOMAXPROCS": ext۰NoEffect,
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"runtime.Goexit": ext۰NoEffect,
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"runtime.GoroutineProfile": ext۰NoEffect,
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"runtime.Gosched": ext۰NoEffect,
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"runtime.MemProfile": ext۰NoEffect,
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"runtime.NumCPU": ext۰NoEffect,
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"runtime.NumGoroutine": ext۰NoEffect,
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"runtime.ReadMemStats": ext۰NoEffect,
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"runtime.SetBlockProfileRate": ext۰NoEffect,
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"runtime.SetCPUProfileRate": ext۰NoEffect,
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"runtime.SetFinalizer": ext۰NotYetImplemented,
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"runtime.Stack": ext۰NoEffect,
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"runtime.ThreadCreateProfile": ext۰NoEffect,
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"runtime.funcentry_go": ext۰NoEffect,
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"runtime.funcline_go": ext۰NoEffect,
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"runtime.funcname_go": ext۰NoEffect,
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"runtime.getgoroot": ext۰NoEffect,
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"runtime/pprof.runtime_cyclesPerSecond": ext۰NoEffect,
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"strings.IndexByte": ext۰NoEffect,
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"sync.runtime_Semacquire": ext۰NoEffect,
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"sync.runtime_Semrelease": ext۰NoEffect,
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"sync.runtime_Syncsemacquire": ext۰NoEffect,
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"sync.runtime_Syncsemcheck": ext۰NoEffect,
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"sync.runtime_Syncsemrelease": ext۰NoEffect,
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"sync/atomic.AddInt32": ext۰NoEffect,
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"sync/atomic.AddUint32": ext۰NoEffect,
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"sync/atomic.CompareAndSwapInt32": ext۰NoEffect,
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"sync/atomic.CompareAndSwapUint32": ext۰NoEffect,
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"sync/atomic.CompareAndSwapUint64": ext۰NoEffect,
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"sync/atomic.CompareAndSwapUintptr": ext۰NoEffect,
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"sync/atomic.LoadInt32": ext۰NoEffect,
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"sync/atomic.LoadUint32": ext۰NoEffect,
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"sync/atomic.LoadUint64": ext۰NoEffect,
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"sync/atomic.StoreInt32": ext۰NoEffect,
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"sync/atomic.StoreUint32": ext۰NoEffect,
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"syscall.Close": ext۰NoEffect,
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"syscall.Exit": ext۰NoEffect,
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"syscall.Getpid": ext۰NoEffect,
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"syscall.Getwd": ext۰NoEffect,
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"syscall.Kill": ext۰NoEffect,
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"syscall.RawSyscall": ext۰NoEffect,
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"syscall.RawSyscall6": ext۰NoEffect,
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"syscall.Syscall": ext۰NoEffect,
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"syscall.Syscall6": ext۰NoEffect,
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"syscall.runtime_AfterFork": ext۰NoEffect,
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"syscall.runtime_BeforeFork": ext۰NoEffect,
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"time.Sleep": ext۰NoEffect,
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"time.now": ext۰NoEffect,
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"time.startTimer": ext۰NoEffect,
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"time.stopTimer": ext۰NoEffect,
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}
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}
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// findIntrinsic returns the constraint generation function for an
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// intrinsic function fn, or nil if the function should be handled normally.
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//
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func (a *analysis) findIntrinsic(fn *ssa.Function) intrinsic {
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// Consult the *Function-keyed cache.
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// A cached nil indicates a normal non-intrinsic function.
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impl, ok := a.intrinsics[fn]
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if !ok {
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impl = intrinsicsByName[fn.String()] // may be nil
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// Ensure all "reflect" code is treated intrinsically.
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if impl == nil && fn.Pkg != nil && a.reflectValueObj != nil && a.reflectValueObj.Pkg() == fn.Pkg.Object {
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impl = ext۰NotYetImplemented
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}
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a.intrinsics[fn] = impl
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}
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return impl
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}
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// A trivial intrinsic suitable for any function that does not:
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// 1) induce aliases between its arguments or any global variables;
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// 2) call any functions; or
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// 3) create any labels.
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//
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// Many intrinsics (such as CompareAndSwapInt32) have a fourth kind of
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// effect: loading or storing through a pointer. Though these could
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// be significant, we deliberately ignore them because they are
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// generally not worth the effort.
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//
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// We sometimes violate condition #3 if the function creates only
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// non-function labels, as the control-flow graph is still sound.
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//
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func ext۰NoEffect(a *analysis, cgn *cgnode) {}
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func ext۰NotYetImplemented(a *analysis, cgn *cgnode) {
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// TODO(adonovan): enable this warning when we've implemented
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// enough that it's not unbearably annoying.
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// a.warnf(fn.Pos(), "unsound: intrinsic treatment of %s not yet implemented", fn)
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}
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