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vm.go
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vm.go
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// Copyright 2019 The Scriggo Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package runtime
import (
"context"
"errors"
"io"
"reflect"
"strconv"
"strings"
"sync"
"sync/atomic"
"github.com/open2b/scriggo/ast"
"github.com/open2b/scriggo/native"
)
const NoVariadicArgs = -1
const CurrentFunction = -1
const ReturnString = -1
const maxUint32 = 1<<31 - 1
const stackSize = 512
var envType = reflect.TypeOf((*native.Env)(nil)).Elem()
var emptyInterfaceType = reflect.TypeOf(&[]interface{}{nil}[0]).Elem()
var emptyInterfaceNil = reflect.ValueOf(&[]interface{}{nil}[0]).Elem()
// Converter is implemented by format converters.
type Converter func(src []byte, out io.Writer) error
// A TypeOfFunc function returns a type of a value.
type TypeOfFunc func(reflect.Value) reflect.Type
// A ScriggoType represents a type compiled by Scriggo from a type definition
// or a composite type literal with at least one element with a Scriggo type.
type ScriggoType interface {
reflect.Type
// Wrap wraps a value with a Scriggo type putting into a proxy that exposes
// methods to Go.
Wrap(reflect.Value) reflect.Value
// Unwrap unwraps a value that has been read from Go. If the value given as
// parameter can be unwrapped using the unwrapper's type, the unwrapped
// value is returned and the method returns true.
Unwrap(reflect.Value) (reflect.Value, bool)
// GoType returns the Go type of a Scriggo type. Note that the
// implementation of the reflect.Type returned by GoType is the
// implementation of the package 'reflect', so it's safe to pass the
// returned value to reflect functions and methods as argument.
GoType() reflect.Type
}
type StackShift [4]int8
type Instruction struct {
Op Operation
A, B, C int8
}
func decodeInt16(a, b int8) int16 {
return int16(int(a)<<8 | int(uint8(b)))
}
func decodeUint16(a, b int8) uint16 {
return uint16(uint8(a))<<8 | uint16(uint8(b))
}
func decodeUint24(a, b, c int8) uint32 {
return uint32(uint8(a))<<16 | uint32(uint8(b))<<8 | uint32(uint8(c))
}
func decodeValueIndex(a, b int8) (t registerType, i int) {
return registerType(uint8(a) >> 6), int(decodeUint16(a, b) &^ (3 << 14))
}
// VM represents a Scriggo virtual machine.
type VM struct {
fp [4]Addr // frame pointers.
st [4]Addr // stack tops.
pc Addr // program counter.
ok bool // ok flag.
regs registers // registers.
fn *Function // running function.
vars []reflect.Value // global and closure variables.
env *env // execution environment.
envArg reflect.Value // execution environment as argument.
renderer *renderer // renderer
calls []callFrame // call stack frame.
cases []reflect.SelectCase // select cases.
panic *PanicError // panic.
main bool // reports whether this VM is executing the main goroutine.
}
// NewVM returns a new virtual machine.
func NewVM() *VM {
vm := create(&env{})
vm.main = true
return vm
}
// Reset resets a virtual machine so that it is ready for a new call to Run.
func (vm *VM) Reset() {
vm.fp = [4]Addr{0, 0, 0, 0}
vm.st[0] = Addr(len(vm.regs.int))
vm.st[1] = Addr(len(vm.regs.float))
vm.st[2] = Addr(len(vm.regs.string))
vm.st[3] = Addr(len(vm.regs.general))
vm.pc = 0
vm.ok = false
vm.fn = nil
vm.vars = nil
vm.env = &env{}
vm.envArg = reflect.ValueOf(vm.env)
vm.renderer = nil
if vm.calls != nil {
vm.calls = vm.calls[:0]
}
if vm.cases != nil {
vm.cases = vm.cases[:0]
}
vm.panic = nil
}
// stop is called in the vm.run method to stop the execution.
func (vm *VM) stop() (Addr, bool) {
const maxAddr = 1<<32 - 1
atomic.StoreInt32(&vm.env.done, 1)
return maxAddr, false
}
// Run starts the execution of the function fn with the given global variables
// and waits for it to complete.
//
// During the execution if a panic occurs and has not been recovered, by
// default Run panics with the panic message.
//
// If a context has been set and the context is canceled, Run returns
// as soon as possible with the error returned by the Err method of the
// context.
func (vm *VM) Run(fn *Function, typeof TypeOfFunc, globals []reflect.Value) error {
if typeof == nil {
typeof = typeOfFunc
}
vm.env.typeof = typeof
vm.env.globals = globals
err := vm.runFunc(fn, globals)
if err != nil {
switch e := err.(type) {
case *PanicError:
if outErr, ok := e.message.(outError); ok {
err = outErr.err
}
case *fatalError:
panic(e.msg)
case stopError:
err = e.err
}
return err
}
return nil
}
// SetContext sets the context.
//
// SetContext must not be called after vm has been started.
func (vm *VM) SetContext(ctx context.Context) {
vm.env.ctx = ctx
if ctx != nil {
if done := ctx.Done(); done != nil {
vm.env.doneChan = done
vm.env.doneCase = reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: reflect.ValueOf(done),
}
return
}
}
vm.env.doneChan = nil
vm.env.doneCase = reflect.SelectCase{}
}
// SetRenderer sets template output and markdown converter.
//
// SetRenderer must not be called after vm has been started.
func (vm *VM) SetRenderer(out io.Writer, conv Converter) {
vm.renderer = newRenderer(vm.env, out, conv)
}
// SetPrint sets the "print" builtin function.
//
// SetPrint must not be called after vm has been started.
func (vm *VM) SetPrint(p PrintFunc) {
vm.env.print = p
}
// Stack returns the current stack trace.
func (vm *VM) Stack(buf []byte, all bool) int {
// TODO(marco): implement all == true
if len(buf) == 0 {
return 0
}
b := buf[0:0:len(buf)]
write := func(s string) {
n := copy(b[len(b):cap(b)], s)
b = b[:len(b)+n]
}
write("scriggo goroutine 1 [running]:")
size := len(vm.calls)
for i := size; i >= 0; i-- {
var fn *Function
var ppc Addr
if i == size {
fn = vm.fn
ppc = vm.pc - 1
} else {
call := vm.calls[i]
fn = call.cl.fn
if call.status == tailed {
ppc = call.pc - 1
} else {
ppc = call.pc - 2
}
}
write("\n")
write(packageName(fn.Pkg))
write(".")
write(fn.Name)
write("()\n\t")
if fn.File != "" {
write(fn.File)
} else {
write("???")
}
write(":")
if debugInfo, ok := fn.DebugInfo[ppc]; ok {
write(strconv.Itoa(debugInfo.Position.Line))
} else {
write("???")
}
if len(b) == len(buf) {
break
}
}
return len(b)
}
// callNative calls a native function. numVariadic is the number of variadic
// arguments, shift is the stack shift and asGoroutine reports whether the
// function must be started as a goroutine.
//
// When callNative is called, vm.pc must be the address of the call
// instruction plus one.
func (vm *VM) callNative(fn *NativeFunction, numVariadic int8, shift StackShift, asGoroutine bool) {
if fn.value.IsNil() {
panic(errNilPointer)
}
// Make a copy of the frame pointer.
fp := vm.fp
// Shift the frame pointer.
vm.fp[0] += Addr(shift[0])
vm.fp[1] += Addr(shift[1])
vm.fp[2] += Addr(shift[2])
vm.fp[3] += Addr(shift[3])
// Call the function without the reflect.
if !fn.reflectCall {
if asGoroutine {
switch f := fn.function.(type) {
case func(string) int:
go f(vm.string(1))
case func(string) string:
go f(vm.string(2))
case func(string, string) int:
go f(vm.string(1), vm.string(2))
case func(string, int) string:
go f(vm.string(2), int(vm.int(1)))
case func(string, string) bool:
go f(vm.string(1), vm.string(2))
default:
panic("unexpected")
}
} else {
switch f := fn.function.(type) {
case func(string) int:
vm.setInt(1, int64(f(vm.string(1))))
case func(string) string:
vm.setString(1, f(vm.string(2)))
case func(string, string) int:
vm.setInt(1, int64(f(vm.string(1), vm.string(2))))
case func(string, int) string:
vm.setString(1, f(vm.string(2), int(vm.int(1))))
case func(string, string) bool:
vm.setBool(1, f(vm.string(1), vm.string(2)))
default:
panic("unexpected")
}
}
vm.fp = fp
return
}
// Call the function with reflect.
var args []reflect.Value
typ := fn.value.Type()
nunIn := typ.NumIn()
variadic := typ.IsVariadic()
if nunIn > 0 {
// Shift the frame pointer.
vm.fp[0] += Addr(fn.outOff[0])
vm.fp[1] += Addr(fn.outOff[1])
vm.fp[2] += Addr(fn.outOff[2])
vm.fp[3] += Addr(fn.outOff[3])
// Get a slice of reflect.Value for the arguments.
args = fn.argsPool.Get().([]reflect.Value)
// Prepare the arguments.
lastNonVariadic := nunIn
if variadic && numVariadic != NoVariadicArgs {
lastNonVariadic--
}
for i := 0; i < nunIn; i++ {
if i < lastNonVariadic {
if i < 2 && typ.In(i) == envType {
// Set the path of the file that contains the call.
if vm.main {
env := vm.env
env.mu.Lock()
env.callPath = vm.fn.DebugInfo[vm.pc-1].Path
env.mu.Unlock()
}
args[i].Set(vm.envArg)
} else {
r := vm.getIntoReflectValue(1, args[i], false)
vm.fp[r]++
}
} else {
sliceType := args[i].Type()
slice := reflect.MakeSlice(sliceType, int(numVariadic), int(numVariadic))
k := sliceType.Elem().Kind()
switch k {
case reflect.Bool:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).SetBool(vm.bool(int8(j + 1)))
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).SetInt(vm.int(int8(j + 1)))
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).SetUint(uint64(vm.int(int8(j + 1))))
}
case reflect.Float32, reflect.Float64:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).SetFloat(vm.float(int8(j + 1)))
}
case reflect.Func:
for j := 0; j < int(numVariadic); j++ {
f := vm.general(int8(j + 1)).Interface().(*callable)
slice.Index(j).Set(f.Value(vm.renderer, vm.env))
}
case reflect.String:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).SetString(vm.string(int8(j + 1)))
}
case reflect.Interface:
for j := 0; j < int(numVariadic); j++ {
if v := vm.general(int8(j + 1)); !v.IsValid() {
if t := slice.Index(j).Type(); t == emptyInterfaceType {
slice.Index(j).Set(emptyInterfaceNil)
} else {
slice.Index(j).Set(reflect.Zero(t))
}
} else {
slice.Index(j).Set(v)
}
}
default:
for j := 0; j < int(numVariadic); j++ {
slice.Index(j).Set(vm.general(int8(j + 1)))
}
}
args[i].Set(slice)
}
}
// Shift the frame pointer.
vm.fp[0] = fp[0] + Addr(shift[0])
vm.fp[1] = fp[1] + Addr(shift[1])
vm.fp[2] = fp[2] + Addr(shift[2])
vm.fp[3] = fp[3] + Addr(shift[3])
}
if asGoroutine {
// Start a goroutine.
if variadic {
go fn.value.CallSlice(args)
} else {
go fn.value.Call(args)
}
} else {
// Call the function and get the results.
var out []reflect.Value
if variadic {
out = fn.value.CallSlice(args)
} else {
out = fn.value.Call(args)
}
for _, arg := range out {
r := vm.setFromReflectValue(1, arg)
vm.fp[r]++
}
if args != nil {
fn.argsPool.Put(args)
}
}
vm.fp = fp // Restore the frame pointer.
return
}
// equals reports whether x and y are equal.
// It panics if x and y are not comparable.
//
// If x and y are not interfaces and are guaranteed to have the same type,
// x.Interface() == y.Interface() can be used as a faster alternative.
func (vm *VM) equals(x, y reflect.Value) bool {
if x.IsValid() != y.IsValid() {
return false
}
if !x.IsValid() {
return true
}
tx := vm.env.typeof(x)
ty := vm.env.typeof(y)
if tx != ty {
return false
}
if t, ok := tx.(ScriggoType); ok {
if !tx.Comparable() {
panic("runtime error: comparing uncomparable type " + tx.String())
}
x, _ = t.Unwrap(x)
y, _ = t.Unwrap(y)
}
return x.Interface() == y.Interface()
}
// fieldByIndex returns the field of the struct s at index i.
// s can be a pointer to a struct value.
//
// It panics with errNilPointer if s represents a nil pointer or accessing
// to a nil embedded struct.
func (vm *VM) fieldByIndex(s reflect.Value, i uint8) reflect.Value {
v := s
for _, x := range vm.fn.FieldIndexes[i] {
if v.Kind() == reflect.Ptr {
if v.IsNil() {
panic(errNilPointer)
}
v = v.Elem()
}
v = v.Field(x)
}
return v
}
func (vm *VM) finalize(regs [][2]int8) {
for _, reg := range regs {
vm.setFromReflectValue(reg[1], vm.generalIndirect(reg[0]))
}
}
func (vm *VM) moreIntStack() {
top := len(vm.regs.int) * 2
stack := make([]int64, top)
copy(stack, vm.regs.int)
vm.regs.int = stack
vm.st[0] = Addr(top)
}
func (vm *VM) moreFloatStack() {
top := len(vm.regs.float) * 2
stack := make([]float64, top)
copy(stack, vm.regs.float)
vm.regs.float = stack
vm.st[1] = Addr(top)
}
func (vm *VM) moreStringStack() {
top := len(vm.regs.string) * 2
stack := make([]string, top)
copy(stack, vm.regs.string)
vm.regs.string = stack
vm.st[2] = Addr(top)
}
func (vm *VM) moreGeneralStack() {
top := len(vm.regs.general) * 2
stack := make([]reflect.Value, top)
copy(stack, vm.regs.general)
vm.regs.general = stack
vm.st[3] = Addr(top)
}
func (vm *VM) nextCall() bool {
for i := len(vm.calls) - 1; i >= 0; i-- {
call := vm.calls[i]
switch call.status {
case started:
// A call is returned, continue with the previous call.
case tailed:
// A tail call is returned, continue with the previous call.
continue
case deferred:
// A call, that has deferred calls, is returned, its first
// deferred call will be executed.
current := callFrame{cl: callable{fn: vm.fn}, renderer: vm.renderer, fp: vm.fp, status: returned}
vm.swapStack(&call.fp, ¤t.fp, current.cl.fn.NumReg)
vm.calls[i] = current
i++
case returned, recovered:
// A deferred call is returned. If there is another deferred
// call, it will be executed, otherwise the previous call will be
// finalized.
if i > 0 {
prev := vm.calls[i-1]
if prev.status == deferred {
vm.swapStack(&prev.fp, &call.fp, call.cl.fn.NumReg)
call, vm.calls[i-1] = prev, call
break
}
}
if regs := call.cl.fn.FinalRegs; regs != nil {
vm.fp = call.fp
vm.finalize(regs)
}
if call.status == recovered {
numPanicked := 0
for _, c := range vm.calls {
if c.status == panicked {
numPanicked++
}
}
num := 0
for p := vm.panic; p != nil; p = p.next {
num++
}
for p := vm.panic; num > numPanicked; num-- {
p = p.next
vm.panic = p
}
}
continue
case panicked:
// A call is panicked, the first deferred call in the call stack,
// if there is one, will be executed.
for i = i - 1; i >= 0; i-- {
call = vm.calls[i]
if call.status == deferred {
vm.calls[i] = vm.calls[i+1]
vm.calls[i].status = panicked
if call.cl.fn != nil {
i++
}
break
}
}
}
if i >= 0 {
if call.cl.fn != nil {
vm.calls = vm.calls[:i]
vm.fp = call.fp
vm.pc = call.pc
vm.fn = call.cl.fn
vm.vars = call.cl.vars
vm.renderer = call.renderer
return true
}
vm.fp = call.fp
vm.callNative(call.cl.Native(), call.numVariadic, StackShift{}, false)
}
}
return false
}
// create creates a new virtual machine with the execution environment env.
func create(env *env) *VM {
vm := &VM{
st: [4]Addr{stackSize, stackSize, stackSize, stackSize},
regs: registers{
int: make([]int64, stackSize),
float: make([]float64, stackSize),
string: make([]string, stackSize),
general: make([]reflect.Value, stackSize),
},
}
if env != nil {
vm.env = env
vm.envArg = reflect.ValueOf(env)
}
return vm
}
// startGoroutine starts a new goroutine to execute a function call at program
// counter pc. If the function is native, returns true.
func (vm *VM) startGoroutine() bool {
var fn *Function
var vars []reflect.Value
call := vm.fn.Body[vm.pc]
switch call.Op {
case OpCallFunc:
fn = vm.fn.Functions[uint8(call.A)]
vars = vm.env.globals
case OpCallIndirect:
f := vm.general(call.A).Interface().(*callable)
if f.fn == nil {
if f.native.value.IsNil() {
panic(errors.New("fatal error: go of nil func value"))
}
return true
}
fn = f.fn
vars = f.vars
default:
return true
}
nvm := create(vm.env)
vm.pc++
off := vm.fn.Body[vm.pc]
copy(nvm.regs.int, vm.regs.int[vm.fp[0]+Addr(off.Op):vm.fp[0]+127])
copy(nvm.regs.float, vm.regs.float[vm.fp[1]+Addr(off.A):vm.fp[1]+127])
copy(nvm.regs.string, vm.regs.string[vm.fp[2]+Addr(off.B):vm.fp[2]+127])
copy(nvm.regs.general, vm.regs.general[vm.fp[3]+Addr(off.C):vm.fp[3]+127])
go nvm.runFunc(fn, vars)
vm.pc++
return false
}
// swapStack swaps the stacks pointed by a and b. bSize is the size of the
// stack pointed by b. The stacks must be consecutive and a must precede b.
//
// A stack can have zero size, so a and b can point to the same index.
func (vm *VM) swapStack(a, b *[4]Addr, bSize StackShift) {
// Swap int registers.
as := b[0] - a[0]
bs := Addr(bSize[0])
if as > 0 && bs > 0 {
tot := as + bs
if a[0]+tot+bs > vm.st[0] {
vm.moreIntStack()
}
s := vm.regs.int[a[0]+1:]
copy(s[bs:], s[:tot])
copy(s, s[tot:tot+bs])
}
b[0] = a[0]
a[0] += bs
// Swap float registers.
as = b[1] - a[1]
bs = Addr(bSize[1])
if as > 0 && bs > 0 {
tot := as + bs
if a[1]+tot+bs > vm.st[1] {
vm.moreFloatStack()
}
s := vm.regs.float[a[1]+1:]
copy(s[bs:], s[:tot])
copy(s, s[tot:tot+bs])
}
b[1] = a[1]
a[1] += bs
// Swap string registers.
as = b[2] - a[2]
bs = Addr(bSize[2])
if as > 0 && bs > 0 {
tot := as + bs
if a[2]+tot+bs > vm.st[2] {
vm.moreStringStack()
}
s := vm.regs.string[a[2]+1:]
copy(s[bs:], s[:tot])
copy(s, s[tot:tot+bs])
}
b[2] = a[2]
a[2] += bs
// Swap general registers.
as = b[3] - a[3]
bs = Addr(bSize[3])
if as > 0 && bs > 0 {
tot := as + bs
if a[3]+tot+bs > vm.st[3] {
vm.moreGeneralStack()
}
s := vm.regs.general[a[3]+1:]
copy(s[bs:], s[:tot])
copy(s, s[tot:tot+bs])
}
b[3] = a[3]
a[3] += bs
}
type Registers struct {
Int []int64
Float []float64
String []string
General []reflect.Value
}
// macroOutBuffer is used in CallMacro and CallIndirect instructions to buffer
// the out of a macro call and convert it to a string in Return instructions.
type macroOutBuffer struct {
strings.Builder
}
type NativeFunction struct {
pkg string // package.
name string // name.
function interface{} // value.
outOff [4]int8 // offset of out arguments.
value reflect.Value // reflect value.
reflectCall bool // reports whether it can be called only with reflect.
argsPool *sync.Pool // pool of arguments for reflect.Call and reflect.CallSlice.
}
// NewNativeFunction returns a new native function given its package and name
// and the function value or its reflect value. pkg and name can be empty
// strings.
func NewNativeFunction(pkg, name string, function interface{}) *NativeFunction {
fn := &NativeFunction{
pkg: pkg,
name: name,
}
if value, ok := function.(reflect.Value); ok {
fn.function = value.Interface()
fn.value = value
} else {
fn.function = function
fn.value = reflect.ValueOf(function)
}
typ := fn.value.Type()
nOut := typ.NumOut()
for i := 0; i < nOut; i++ {
k := typ.Out(i).Kind()
fn.outOff[kindToType[k]]++
}
switch fn.function.(type) {
case func(string) int:
case func(string) string:
case func(string, string) int:
case func(string, int) string:
case func(string, string) bool:
default:
fn.reflectCall = true
if numIn := typ.NumIn(); numIn > 0 {
fn.argsPool = &sync.Pool{
New: func() interface{} {
args := make([]reflect.Value, numIn)
for i := 0; i < numIn; i++ {
t := typ.In(i)
args[i] = reflect.New(t).Elem()
}
return args
},
}
}
}
return fn
}
func (fn *NativeFunction) Package() string {
return fn.pkg
}
func (fn *NativeFunction) Name() string {
return fn.name
}
func (fn *NativeFunction) Func() interface{} {
return fn.function
}
// Function represents a function.
type Function struct {
Pkg string
Name string
File string
Pos *Position // position of the function declaration.
Type reflect.Type
Parent *Function
VarRefs []int16
Types []reflect.Type
NumReg [4]int8
FinalRegs [][2]int8 // [indirect -> return parameter registers]
Macro bool
Format ast.Format
Values Registers
FieldIndexes [][]int
Functions []*Function
NativeFunctions []*NativeFunction
Body []Instruction
Text [][]byte
DebugInfo map[Addr]DebugInfo
}
// Position represents a source position.
type Position struct {
Line int // line starting from 1
Column int // column in characters starting from 1
Start int // index of the first byte
End int // index of the last byte
}
func (p Position) String() string {
return strconv.Itoa(p.Line) + ":" + strconv.Itoa(p.Column)
}
// DebugInfo represents a set of debug information associated to a given
// instruction. None of the fields below is mandatory.
type DebugInfo struct {
Position Position // position of the instruction in the source code.
Path string // path of the source code where the instruction is located in.
OperandKind [3]reflect.Kind // kind of operands A, B and C.
FuncType reflect.Type // type of the function that is called; only for call instructions.
}
type Addr uint32
type callStatus int8
const (
started callStatus = iota
tailed
returned
deferred
panicked
recovered
)
// If the size of callFrame changes, update the constant CallFrameSize.
type callFrame struct {
cl callable // callable.
renderer *renderer // renderer
fp [4]Addr // frame pointers.
pc Addr // program counter.
status callStatus // status.
numVariadic int8 // number of variadic arguments.
}
type callable struct {
value reflect.Value // reflect value.
fn *Function // function, if it is a Scriggo function.
native *NativeFunction // native function.
vars []reflect.Value // non-local (global and closure) variables.
}
// Native returns the native function of a callable.
func (c *callable) Native() *NativeFunction {
if c.native != nil {
return c.native
}
c.native = NewNativeFunction("", "", c.value)
return c.native
}
// Value returns a reflect Value of a callable, so it can be called from a
// native code and passed to a native code.
func (c *callable) Value(renderer *renderer, env *env) reflect.Value {
if c.value.IsValid() {
return c.value
}
if c.native != nil {
// It is a native function.
c.value = reflect.ValueOf(c.native.function)
return c.value
}
// It is a Scriggo function.
fn := c.fn
vars := c.vars
c.value = reflect.MakeFunc(fn.Type, func(args []reflect.Value) []reflect.Value {
nvm := create(env)
if fn.Macro {
renderer = renderer.WithOut(¯oOutBuffer{})
}
nvm.renderer = renderer
nOut := fn.Type.NumOut()
results := make([]reflect.Value, nOut)
var r = [4]int8{1, 1, 1, 1}
for i := 0; i < nOut; i++ {
typ := fn.Type.Out(i)
results[i] = reflect.New(typ).Elem()
t := kindToType[typ.Kind()]
r[t]++
}
for _, arg := range args {
t := kindToType[arg.Kind()]
nvm.setFromReflectValue(r[t], arg)
r[t]++
}
err := nvm.runFunc(fn, vars)
if err != nil {
if p, ok := err.(*PanicError); ok {
var msg string
for ; p != nil; p = p.next {
msg = "\n" + msg
if p.recovered {
msg = " [recovered]" + msg
}
msg = p.String() + msg
if p.next != nil {
msg = "\tpanic: " + msg
}
}
err = &fatalError{msg: msg}
}
panic(err)
}
if fn.Macro {
b := renderer.Out().(*macroOutBuffer)
nvm.setString(1, b.String())
err := renderer.Close()
if err != nil {
panic(&fatalError{env: env, msg: err})
}
}
r = [4]int8{1, 1, 1, 1}
for _, result := range results {
t := kindToType[result.Kind()]
nvm.getIntoReflectValue(r[t], result, false)
r[t]++
}
return results
})
return c.value
}
func packageName(pkg string) string {
for i := len(pkg) - 1; i >= 0; i-- {
if pkg[i] == '/' {
return pkg[i+1:]
}
}
return pkg
}
type registerType int8
const (
intRegister registerType = iota
floatRegister
stringRegister
generalRegister
)
// kindToType maps a reflect kind to the corresponding internal register type.
var kindToType = [...]registerType{
reflect.Float32: floatRegister,
reflect.Float64: floatRegister,
reflect.Complex64: generalRegister,
reflect.Complex128: generalRegister,
reflect.Array: generalRegister,
reflect.Chan: generalRegister,
reflect.Func: generalRegister,
reflect.Interface: generalRegister,
reflect.Map: generalRegister,
reflect.Ptr: generalRegister,
reflect.Slice: generalRegister,
reflect.String: stringRegister,
reflect.Struct: generalRegister,
reflect.UnsafePointer: generalRegister,
}
type Condition int8