Exemplo n.º 1
0
func initReflect(i *interpreter) {
	i.reflectPackage = &ssa.Package{
		Prog:    i.prog,
		Pkg:     reflectTypesPackage,
		Members: make(map[string]ssa.Member),
	}

	// Clobber the type-checker's notion of reflect.Value's
	// underlying type so that it more closely matches the fake one
	// (at least in the number of fields---we lie about the type of
	// the rtype field).
	//
	// We must ensure that calls to (ssa.Value).Type() return the
	// fake type so that correct "shape" is used when allocating
	// variables, making zero values, loading, and storing.
	//
	// TODO(adonovan): obviously this is a hack.  We need a cleaner
	// way to fake the reflect package (almost---DeepEqual is fine).
	// One approach would be not to even load its source code, but
	// provide fake source files.  This would guarantee that no bad
	// information leaks into other packages.
	if r := i.prog.ImportedPackage("reflect"); r != nil {
		rV := r.Pkg.Scope().Lookup("Value").Type().(*types.Named)

		// delete bodies of the old methods
		mset := i.prog.MethodSets.MethodSet(rV)
		for j := 0; j < mset.Len(); j++ {
			i.prog.MethodValue(mset.At(j)).Blocks = nil
		}

		tEface := types.NewInterface(nil, nil).Complete()
		rV.SetUnderlying(types.NewStruct([]*types.Var{
			types.NewField(token.NoPos, r.Pkg, "t", tEface, false), // a lie
			types.NewField(token.NoPos, r.Pkg, "v", tEface, false),
		}, nil))
	}

	i.rtypeMethods = methodSet{
		"Bits":      newMethod(i.reflectPackage, rtypeType, "Bits"),
		"Elem":      newMethod(i.reflectPackage, rtypeType, "Elem"),
		"Field":     newMethod(i.reflectPackage, rtypeType, "Field"),
		"In":        newMethod(i.reflectPackage, rtypeType, "In"),
		"Kind":      newMethod(i.reflectPackage, rtypeType, "Kind"),
		"NumField":  newMethod(i.reflectPackage, rtypeType, "NumField"),
		"NumIn":     newMethod(i.reflectPackage, rtypeType, "NumIn"),
		"NumMethod": newMethod(i.reflectPackage, rtypeType, "NumMethod"),
		"NumOut":    newMethod(i.reflectPackage, rtypeType, "NumOut"),
		"Out":       newMethod(i.reflectPackage, rtypeType, "Out"),
		"Size":      newMethod(i.reflectPackage, rtypeType, "Size"),
		"String":    newMethod(i.reflectPackage, rtypeType, "String"),
	}
	i.errorMethods = methodSet{
		"Error": newMethod(i.reflectPackage, errorType, "Error"),
	}
}
Exemplo n.º 2
0
func (p *importer) field() *types.Var {
	pkg, name := p.qualifiedName()
	typ := p.typ()

	anonymous := false
	if name == "" {
		// anonymous field - typ must be T or *T and T must be a type name
		switch typ := deref(typ).(type) {
		case *types.Basic: // basic types are named types
			pkg = nil
			name = typ.Name()
		case *types.Named:
			obj := typ.Obj()
			name = obj.Name()
			// correct the field package for anonymous fields
			if exported(name) {
				pkg = p.pkgList[0]
			}
		default:
			panic("anonymous field expected")
		}
		anonymous = true
	}

	return types.NewField(token.NoPos, pkg, name, typ, anonymous)
}
Exemplo n.º 3
0
// Field = Name Type [ string_lit ] .
//
func (p *parser) parseField() (*types.Var, string) {
	pkg, name := p.parseName(true)
	typ := p.parseType()
	anonymous := false
	if name == "" {
		// anonymous field - typ must be T or *T and T must be a type name
		switch typ := deref(typ).(type) {
		case *types.Basic: // basic types are named types
			pkg = nil
			name = typ.Name()
		case *types.Named:
			name = typ.Obj().Name()
		default:
			p.errorf("anonymous field expected")
		}
		anonymous = true
	}
	tag := ""
	if p.tok == scanner.String {
		s := p.expect(scanner.String)
		var err error
		tag, err = strconv.Unquote(s)
		if err != nil {
			p.errorf("invalid struct tag %s: %s", s, err)
		}
	}
	return types.NewField(token.NoPos, pkg, name, typ, anonymous), tag
}
Exemplo n.º 4
0
// makeClosure creates a closure from a function pointer and
// a set of bindings. The bindings are addresses of captured
// variables.
func (fr *frame) makeClosure(fn *govalue, bindings []*govalue) *govalue {
	govalues := append([]*govalue{fn}, bindings...)
	fields := make([]*types.Var, len(govalues))
	for i, v := range govalues {
		field := types.NewField(0, nil, "_", v.Type(), false)
		fields[i] = field
	}
	block := fr.createTypeMalloc(types.NewStruct(fields, nil))
	for i, v := range govalues {
		addressPtr := fr.builder.CreateStructGEP(block, i, "")
		fr.builder.CreateStore(v.value, addressPtr)
	}
	closure := fr.builder.CreateBitCast(block, fn.value.Type(), "")
	return newValue(closure, fn.Type())
}
Exemplo n.º 5
0
// Field = Name Type [string] .
func (p *parser) parseField(pkg *types.Package) (field *types.Var, tag string) {
	name := p.parseName()
	typ := p.parseType(pkg)
	anon := false
	if name == "" {
		anon = true
		switch typ := deref(typ).(type) {
		case *types.Basic:
			name = typ.Name()
		case *types.Named:
			name = typ.Obj().Name()
		default:
			p.error("anonymous field expected")
		}
	}
	field = types.NewField(token.NoPos, pkg, name, typ, anon)
	if p.tok == scanner.String {
		tag = p.parseString()
	}
	return
}
Exemplo n.º 6
0
// createThunk creates a thunk from a
// given function and arguments, suitable for use with
// "defer" and "go".
func (fr *frame) createThunk(call ssa.CallInstruction) (thunk llvm.Value, arg llvm.Value) {
	seenarg := make(map[ssa.Value]bool)
	var args []ssa.Value
	var argtypes []*types.Var

	packArg := func(arg ssa.Value) {
		switch arg.(type) {
		case *ssa.Builtin, *ssa.Function, *ssa.Const, *ssa.Global:
			// Do nothing: we can generate these in the thunk
		default:
			if !seenarg[arg] {
				seenarg[arg] = true
				args = append(args, arg)
				field := types.NewField(0, nil, "_", arg.Type(), true)
				argtypes = append(argtypes, field)
			}
		}
	}

	packArg(call.Common().Value)
	for _, arg := range call.Common().Args {
		packArg(arg)
	}

	var isRecoverCall bool
	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	var structllptr llvm.Type
	if len(args) == 0 {
		if builtin, ok := call.Common().Value.(*ssa.Builtin); ok {
			isRecoverCall = builtin.Name() == "recover"
		}
		if isRecoverCall {
			// When creating a thunk for recover(), we must pass fr.canRecover.
			arg = fr.builder.CreateZExt(fr.canRecover, fr.target.IntPtrType(), "")
			arg = fr.builder.CreateIntToPtr(arg, i8ptr, "")
		} else {
			arg = llvm.ConstPointerNull(i8ptr)
		}
	} else {
		structtype := types.NewStruct(argtypes, nil)
		arg = fr.createTypeMalloc(structtype)
		structllptr = arg.Type()
		for i, ssaarg := range args {
			argptr := fr.builder.CreateStructGEP(arg, i, "")
			fr.builder.CreateStore(fr.llvmvalue(ssaarg), argptr)
		}
		arg = fr.builder.CreateBitCast(arg, i8ptr, "")
	}

	thunkfntype := llvm.FunctionType(llvm.VoidType(), []llvm.Type{i8ptr}, false)
	thunkfn := llvm.AddFunction(fr.module.Module, "", thunkfntype)
	thunkfn.SetLinkage(llvm.InternalLinkage)
	fr.addCommonFunctionAttrs(thunkfn)

	thunkfr := newFrame(fr.unit, thunkfn)
	defer thunkfr.dispose()

	prologuebb := llvm.AddBasicBlock(thunkfn, "prologue")
	thunkfr.builder.SetInsertPointAtEnd(prologuebb)

	if isRecoverCall {
		thunkarg := thunkfn.Param(0)
		thunkarg = thunkfr.builder.CreatePtrToInt(thunkarg, fr.target.IntPtrType(), "")
		thunkfr.canRecover = thunkfr.builder.CreateTrunc(thunkarg, llvm.Int1Type(), "")
	} else if len(args) > 0 {
		thunkarg := thunkfn.Param(0)
		thunkarg = thunkfr.builder.CreateBitCast(thunkarg, structllptr, "")
		for i, ssaarg := range args {
			thunkargptr := thunkfr.builder.CreateStructGEP(thunkarg, i, "")
			thunkarg := thunkfr.builder.CreateLoad(thunkargptr, "")
			thunkfr.env[ssaarg] = newValue(thunkarg, ssaarg.Type())
		}
	}

	_, isDefer := call.(*ssa.Defer)

	entrybb := llvm.AddBasicBlock(thunkfn, "entry")
	br := thunkfr.builder.CreateBr(entrybb)
	thunkfr.allocaBuilder.SetInsertPointBefore(br)

	thunkfr.builder.SetInsertPointAtEnd(entrybb)
	var exitbb llvm.BasicBlock
	if isDefer {
		exitbb = llvm.AddBasicBlock(thunkfn, "exit")
		thunkfr.runtime.setDeferRetaddr.call(thunkfr, llvm.BlockAddress(thunkfn, exitbb))
	}
	if isDefer && isRecoverCall {
		thunkfr.callRecover(true)
	} else {
		thunkfr.callInstruction(call)
	}
	if isDefer {
		thunkfr.builder.CreateBr(exitbb)
		thunkfr.builder.SetInsertPointAtEnd(exitbb)
	}
	thunkfr.builder.CreateRetVoid()

	thunk = fr.builder.CreateBitCast(thunkfn, i8ptr, "")
	return
}