Golang types.NewPointer函数代码示例

func (d *DIBuilder) descriptorInterface(t *types.Interface, name string) llvm.Metadata {
	ifaceStruct := types.NewStruct([]*types.Var{
		types.NewVar(0, nil, "type", types.NewPointer(types.Typ[types.Uint8])),
		types.NewVar(0, nil, "data", types.NewPointer(types.Typ[types.Uint8])),
	}, nil)
	return d.typeDebugDescriptor(ifaceStruct, name)
}

// emitNew emits to f a new (heap Alloc) instruction allocating an
// object of type typ.  pos is the optional source location.
//
func emitNew(f *Function, typ types.Type, pos token.Pos) *Alloc {
	v := &Alloc{Heap: true}
	v.setType(types.NewPointer(typ))
	v.setPos(pos)
	f.emit(v)
	return v
}

// emitFieldSelection emits to f code to select the index'th field of v.
//
// If wantAddr, the input must be a pointer-to-struct and the result
// will be the field's address; otherwise the result will be the
// field's value.
// Ident id is used for position and debug info.
//
func emitFieldSelection(f *Function, v Value, index int, wantAddr bool, id *ast.Ident) Value {
	fld := deref(v.Type()).Underlying().(*types.Struct).Field(index)
	if isPointer(v.Type()) {
		instr := &FieldAddr{
			X:     v,
			Field: index,
		}
		instr.setPos(id.Pos())
		instr.setType(types.NewPointer(fld.Type()))
		v = f.emit(instr)
		// Load the field's value iff we don't want its address.
		if !wantAddr {
			v = emitLoad(f, v)
		}
	} else {
		instr := &Field{
			X:     v,
			Field: index,
		}
		instr.setPos(id.Pos())
		instr.setType(fld.Type())
		v = f.emit(instr)
	}
	emitDebugRef(f, id, v, wantAddr)
	return v
}

// emitImplicitSelections emits to f code to apply the sequence of
// implicit field selections specified by indices to base value v, and
// returns the selected value.
//
// If v is the address of a struct, the result will be the address of
// a field; if it is the value of a struct, the result will be the
// value of a field.
//
func emitImplicitSelections(f *Function, v Value, indices []int) Value {
	for _, index := range indices {
		fld := deref(v.Type()).Underlying().(*types.Struct).Field(index)

		if isPointer(v.Type()) {
			instr := &FieldAddr{
				X:     v,
				Field: index,
			}
			instr.setType(types.NewPointer(fld.Type()))
			v = f.emit(instr)
			// Load the field's value iff indirectly embedded.
			if isPointer(fld.Type()) {
				v = emitLoad(f, v)
			}
		} else {
			instr := &Field{
				X:     v,
				Field: index,
			}
			instr.setType(fld.Type())
			v = f.emit(instr)
		}
	}
	return v
}

// PointerType = "*" ("any" | Type) .
func (p *parser) parsePointerType(pkg *types.Package) types.Type {
	p.expect('*')
	if p.tok == scanner.Ident {
		p.expectKeyword("any")
		return types.Typ[types.UnsafePointer]
	}
	return types.NewPointer(p.parseType(pkg))
}

func (d *DIBuilder) descriptorSlice(t *types.Slice, name string) llvm.Metadata {
	sliceStruct := types.NewStruct([]*types.Var{
		types.NewVar(0, nil, "ptr", types.NewPointer(t.Elem())),
		types.NewVar(0, nil, "len", types.Typ[types.Int]),
		types.NewVar(0, nil, "cap", types.Typ[types.Int]),
	}, nil)
	return d.typeDebugDescriptor(sliceStruct, name)
}

// addLocal creates an anonymous local variable of type typ, adds it
// to function f and returns it.  pos is the optional source location.
//
func (f *Function) addLocal(typ types.Type, pos token.Pos) *Alloc {
	v := &Alloc{}
	v.setType(types.NewPointer(typ))
	v.setPos(pos)
	f.Locals = append(f.Locals, v)
	f.emit(v)
	return v
}

// memberFromObject populates package pkg with a member for the
// typechecker object obj.
//
// For objects from Go source code, syntax is the associated syntax
// tree (for funcs and vars only); it will be used during the build
// phase.
//
func memberFromObject(pkg *Package, obj types.Object, syntax ast.Node) {
	name := obj.Name()
	switch obj := obj.(type) {
	case *types.TypeName:
		pkg.Members[name] = &Type{
			object: obj,
			pkg:    pkg,
		}

	case *types.Const:
		c := &NamedConst{
			object: obj,
			Value:  NewConst(obj.Val(), obj.Type()),
			pkg:    pkg,
		}
		pkg.values[obj] = c.Value
		pkg.Members[name] = c

	case *types.Var:
		g := &Global{
			Pkg:    pkg,
			name:   name,
			object: obj,
			typ:    types.NewPointer(obj.Type()), // address
			pos:    obj.Pos(),
		}
		pkg.values[obj] = g
		pkg.Members[name] = g

	case *types.Func:
		sig := obj.Type().(*types.Signature)
		if sig.Recv() == nil && name == "init" {
			pkg.ninit++
			name = fmt.Sprintf("init#%d", pkg.ninit)
		}
		fn := &Function{
			name:      name,
			object:    obj,
			Signature: sig,
			syntax:    syntax,
			pos:       obj.Pos(),
			Pkg:       pkg,
			Prog:      pkg.Prog,
		}
		if syntax == nil {
			fn.Synthetic = "loaded from gc object file"
		}

		pkg.values[obj] = fn
		if sig.Recv() == nil {
			pkg.Members[name] = fn // package-level function
		}

	default: // (incl. *types.Package)
		panic("unexpected Object type: " + obj.String())
	}
}

// mapIterInit creates a map iterator
func (fr *frame) mapIterInit(m *govalue) []*govalue {
	// We represent an iterator as a tuple (map, *bool). The second element
	// controls whether the code we generate for "next" (below) calls the
	// runtime function for the first or the next element. We let the
	// optimizer reorganize this into something more sensible.
	isinit := fr.allocaBuilder.CreateAlloca(llvm.Int1Type(), "")
	fr.builder.CreateStore(llvm.ConstNull(llvm.Int1Type()), isinit)

	return []*govalue{m, newValue(isinit, types.NewPointer(types.Typ[types.Bool]))}
}

// addSpilledParam declares a parameter that is pre-spilled to the
// stack; the function body will load/store the spilled location.
// Subsequent lifting will eliminate spills where possible.
//
func (f *Function) addSpilledParam(obj types.Object) {
	param := f.addParamObj(obj)
	spill := &Alloc{Comment: obj.Name()}
	spill.setType(types.NewPointer(obj.Type()))
	spill.setPos(obj.Pos())
	f.objects[obj] = spill
	f.Locals = append(f.Locals, spill)
	f.emit(spill)
	f.emit(&Store{Addr: spill, Val: param})
}

// testMainSlice emits to fn code to construct a slice of type slice
// (one of []testing.Internal{Test,Benchmark,Example}) for all
// functions in testfuncs.  It returns the slice value.
//
func testMainSlice(fn *Function, testfuncs []*Function, slice types.Type) Value {
	if testfuncs == nil {
		return nilConst(slice)
	}

	tElem := slice.(*types.Slice).Elem()
	tPtrString := types.NewPointer(tString)
	tPtrElem := types.NewPointer(tElem)
	tPtrFunc := types.NewPointer(funcField(slice))

	// Emit: array = new [n]testing.InternalTest
	tArray := types.NewArray(tElem, int64(len(testfuncs)))
	array := emitNew(fn, tArray, token.NoPos)
	array.Comment = "test main"
	for i, testfunc := range testfuncs {
		// Emit: pitem = &array[i]
		ia := &IndexAddr{X: array, Index: intConst(int64(i))}
		ia.setType(tPtrElem)
		pitem := fn.emit(ia)

		// Emit: pname = &pitem.Name
		fa := &FieldAddr{X: pitem, Field: 0} // .Name
		fa.setType(tPtrString)
		pname := fn.emit(fa)

		// Emit: *pname = "testfunc"
		emitStore(fn, pname, stringConst(testfunc.Name()), token.NoPos)

		// Emit: pfunc = &pitem.F
		fa = &FieldAddr{X: pitem, Field: 1} // .F
		fa.setType(tPtrFunc)
		pfunc := fn.emit(fa)

		// Emit: *pfunc = testfunc
		emitStore(fn, pfunc, testfunc, token.NoPos)
	}

	// Emit: slice array[:]
	sl := &Slice{X: array}
	sl.setType(slice)
	return fn.emit(sl)
}

// Type =
//	BasicType | TypeName | ArrayType | SliceType | StructType |
//      PointerType | FuncType | InterfaceType | MapType | ChanType |
//      "(" Type ")" .
//
// BasicType   = ident .
// TypeName    = ExportedName .
// SliceType   = "[" "]" Type .
// PointerType = "*" Type .
// FuncType    = "func" Signature .
//
func (p *parser) parseType() types.Type {
	switch p.tok {
	case scanner.Ident:
		switch p.lit {
		default:
			return p.parseBasicType()
		case "struct":
			return p.parseStructType()
		case "func":
			// FuncType
			p.next()
			return p.parseSignature(nil)
		case "interface":
			return p.parseInterfaceType()
		case "map":
			return p.parseMapType()
		case "chan":
			return p.parseChanType()
		}
	case '@':
		// TypeName
		pkg, name := p.parseExportedName()
		return declTypeName(pkg, name).Type()
	case '[':
		p.next() // look ahead
		if p.tok == ']' {
			// SliceType
			p.next()
			return types.NewSlice(p.parseType())
		}
		return p.parseArrayType()
	case '*':
		// PointerType
		p.next()
		return types.NewPointer(p.parseType())
	case '<':
		return p.parseChanType()
	case '(':
		// "(" Type ")"
		p.next()
		typ := p.parseType()
		p.expect(')')
		return typ
	}
	p.errorf("expected type, got %s (%q)", scanner.TokenString(p.tok), p.lit)
	return nil
}

// callInstruction translates function call instructions.
func (fr *frame) callInstruction(instr ssa.CallInstruction) []*govalue {
	call := instr.Common()
	if builtin, ok := call.Value.(*ssa.Builtin); ok {
		var typ types.Type
		if v := instr.Value(); v != nil {
			typ = v.Type()
		}
		return fr.callBuiltin(typ, builtin, call.Args)
	}

	args := make([]*govalue, len(call.Args))
	for i, arg := range call.Args {
		args[i] = fr.value(arg)
	}

	var fn *govalue
	var chain llvm.Value
	if call.IsInvoke() {
		var recv *govalue
		fn, recv = fr.interfaceMethod(fr.llvmvalue(call.Value), call.Value.Type(), call.Method)
		args = append([]*govalue{recv}, args...)
	} else {
		if ssafn, ok := call.Value.(*ssa.Function); ok {
			llfn := fr.resolveFunctionGlobal(ssafn)
			llfn = llvm.ConstBitCast(llfn, llvm.PointerType(llvm.Int8Type(), 0))
			fn = newValue(llfn, ssafn.Type())
		} else {
			// First-class function values are stored as *{*fnptr}, so
			// we must extract the function pointer. We must also
			// set the chain, in case the function is a closure.
			fn = fr.value(call.Value)
			chain = fn.value
			fnptr := fr.builder.CreateBitCast(fn.value, llvm.PointerType(fn.value.Type(), 0), "")
			fnptr = fr.builder.CreateLoad(fnptr, "")
			fn = newValue(fnptr, fn.Type())
		}
		if recv := call.Signature().Recv(); recv != nil {
			if _, ok := recv.Type().Underlying().(*types.Pointer); !ok {
				recvalloca := fr.allocaBuilder.CreateAlloca(args[0].value.Type(), "")
				fr.builder.CreateStore(args[0].value, recvalloca)
				args[0] = newValue(recvalloca, types.NewPointer(args[0].Type()))
			}
		}
	}
	return fr.createCall(fn, chain, args)
}

func (tm *llvmTypeMap) getSignatureInfo(sig *types.Signature) functionTypeInfo {
	var args, results []types.Type
	if sig.Recv() != nil {
		recvtype := sig.Recv().Type()
		if _, ok := recvtype.Underlying().(*types.Pointer); !ok && recvtype != types.Typ[types.UnsafePointer] {
			recvtype = types.NewPointer(recvtype)
		}
		args = []types.Type{recvtype}
	}

	for i := 0; i != sig.Params().Len(); i++ {
		args = append(args, sig.Params().At(i).Type())
	}
	for i := 0; i != sig.Results().Len(); i++ {
		results = append(results, sig.Results().At(i).Type())
	}
	return tm.getFunctionTypeInfo(args, results)
}

// IntuitiveMethodSet returns the intuitive method set of a type, T.
//
// The result contains MethodSet(T) and additionally, if T is a
// concrete type, methods belonging to *T if there is no identically
// named method on T itself.  This corresponds to user intuition about
// method sets; this function is intended only for user interfaces.
//
// The order of the result is as for types.MethodSet(T).
//
func IntuitiveMethodSet(T types.Type, msets *types.MethodSetCache) []*types.Selection {
	var result []*types.Selection
	mset := msets.MethodSet(T)
	if _, ok := T.Underlying().(*types.Interface); ok {
		for i, n := 0, mset.Len(); i < n; i++ {
			result = append(result, mset.At(i))
		}
	} else {
		pmset := msets.MethodSet(types.NewPointer(T))
		for i, n := 0, pmset.Len(); i < n; i++ {
			meth := pmset.At(i)
			if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil {
				meth = m
			}
			result = append(result, meth)
		}
	}
	return result
}