func (tm *LLVMTypeMap) Sizeof(typ types.Type) int64 {
switch typ := typ.Underlying().(type) {
case *types.Basic:
switch typ.Kind() {
case types.Int, types.Uint:
return int64(tm.target.TypeAllocSize(tm.inttype))
case types.Uintptr, types.UnsafePointer:
return int64(tm.target.PointerSize())
case types.String:
return 2 * int64(tm.target.PointerSize())
}
return types.DefaultSizeof(typ)
case *types.Array:
eltsize := tm.Sizeof(typ.Elem())
eltalign := tm.Alignof(typ.Elem())
var eltpad int64
if eltsize%eltalign != 0 {
eltpad = eltalign - (eltsize % eltalign)
}
return (eltsize + eltpad) * typ.Len()
case *types.Struct:
if typ.NumFields() == 0 {
return 0
}
fields := make([]*types.Field, int(typ.NumFields()))
for i := range fields {
fields[i] = typ.Field(i)
}
offsets := tm.Offsetsof(fields)
n := len(fields)
return offsets[n-1] + tm.Sizeof(fields[n-1].Type)
}
return int64(tm.target.PointerSize())
}
func ext۰reflect۰rtype۰Size(fn *ssa.Function, args []value) value {
// Signature: func (t reflect.rtype) uintptr
// (Assumes no custom Sizeof used during SSA construction.)
return uintptr(types.DefaultSizeof(args[0].(rtype).t))
}
// Interpret interprets the Go program whose main package is mainpkg.
// mode specifies various interpreter options. filename and args are
// the initial values of os.Args for the target program.
//
// Interpret returns the exit code of the program: 2 for panic (like
// gc does), or the argument to os.Exit for normal termination.
//
func Interpret(mainpkg *ssa.Package, mode Mode, filename string, args []string) (exitCode int) {
i := &interpreter{
prog: mainpkg.Prog,
globals: make(map[ssa.Value]*value),
mode: mode,
}
initReflect(i)
for _, pkg := range i.prog.AllPackages() {
// Initialize global storage.
for _, m := range pkg.Members {
switch v := m.(type) {
case *ssa.Global:
cell := zero(deref(v.Type()))
i.globals[v] = &cell
}
}
// Ad-hoc initialization for magic system variables.
switch pkg.Object.Path() {
case "syscall":
var envs []value
for _, s := range os.Environ() {
envs = append(envs, s)
}
envs = append(envs, "GOSSAINTERP=1")
envs = append(envs, "GOARCH="+runtime.GOARCH)
setGlobal(i, pkg, "envs", envs)
case "runtime":
// (Assumes no custom Sizeof used during SSA construction.)
sz := types.DefaultSizeof(pkg.Object.Scope().Lookup("MemStats").Type())
setGlobal(i, pkg, "sizeof_C_MStats", uintptr(sz))
case "os":
Args := []value{filename}
for _, s := range args {
Args = append(Args, s)
}
setGlobal(i, pkg, "Args", Args)
}
}
// Top-level error handler.
exitCode = 2
defer func() {
if exitCode != 2 || i.mode&DisableRecover != 0 {
return
}
switch p := recover().(type) {
case exitPanic:
exitCode = int(p)
return
case targetPanic:
fmt.Fprintln(os.Stderr, "panic:", toString(p.v))
case runtime.Error:
fmt.Fprintln(os.Stderr, "panic:", p.Error())
case string:
fmt.Fprintln(os.Stderr, "panic:", p)
default:
fmt.Fprintf(os.Stderr, "panic: unexpected type: %T\n", p)
}
// TODO(adonovan): dump panicking interpreter goroutine?
// buf := make([]byte, 0x10000)
// runtime.Stack(buf, false)
// fmt.Fprintln(os.Stderr, string(buf))
// (Or dump panicking target goroutine?)
}()
// Run!
call(i, nil, token.NoPos, mainpkg.Func("init"), nil)
if mainFn := mainpkg.Func("main"); mainFn != nil {
call(i, nil, token.NoPos, mainFn, nil)
exitCode = 0
} else {
fmt.Fprintln(os.Stderr, "No main function.")
exitCode = 1
}
return
}