Golang Function.Pos Examples

Example #1

File: interp.go Project: Bosh-for-Cpi/bosh-2605

// callSSA interprets a call to function fn with arguments args,
// and lexical environment env, returning its result.
// callpos is the position of the callsite.
//
func callSSA(i *interpreter, caller *frame, callpos token.Pos, fn *ssa.Function, args []value, env []value) value {
	if i.mode&EnableTracing != 0 {
		fset := fn.Prog.Fset
		// TODO(adonovan): fix: loc() lies for external functions.
		fmt.Fprintf(os.Stderr, "Entering %s%s.\n", fn, loc(fset, fn.Pos()))
		suffix := ""
		if caller != nil {
			suffix = ", resuming " + caller.fn.String() + loc(fset, callpos)
		}
		defer fmt.Fprintf(os.Stderr, "Leaving %s%s.\n", fn, suffix)
	}
	if fn.Enclosing == nil {
		name := fn.String()
		if ext := externals[name]; ext != nil {
			if i.mode&EnableTracing != 0 {
				fmt.Fprintln(os.Stderr, "\t(external)")
			}
			return ext(fn, args)
		}
		if fn.Blocks == nil {
			panic("no code for function: " + name)
		}
	}
	fr := &frame{
		i:      i,
		caller: caller, // currently unused; for unwinding.
		fn:     fn,
		env:    make(map[ssa.Value]value),
		block:  fn.Blocks[0],
		locals: make([]value, len(fn.Locals)),
	}
	for i, l := range fn.Locals {
		fr.locals[i] = zero(deref(l.Type()))
		fr.env[l] = &fr.locals[i]
	}
	for i, p := range fn.Params {
		fr.env[p] = args[i]
	}
	for i, fv := range fn.FreeVars {
		fr.env[fv] = env[i]
	}
	for fr.block != nil {
		runFrame(fr)
	}
	// Destroy the locals to avoid accidental use after return.
	for i := range fn.Locals {
		fr.locals[i] = bad{}
	}
	return fr.result
}

Example #2

File: interp.go Project: pombredanne/go.tools

// callSSA interprets a call to function fn with arguments args,
// and lexical environment env, returning its result.
// callpos is the position of the callsite.
//
func callSSA(i *interpreter, caller *frame, callpos token.Pos, fn *ssa.Function, args []value, env []value) value {
	if i.mode&EnableTracing != 0 {
		fset := fn.Prog.Files
		// TODO(adonovan): fix: loc() lies for external functions.
		fmt.Fprintf(os.Stderr, "Entering %s%s.\n", fn.FullName(), loc(fset, fn.Pos()))
		suffix := ""
		if caller != nil {
			suffix = ", resuming " + caller.fn.FullName() + loc(fset, callpos)
		}
		defer fmt.Fprintf(os.Stderr, "Leaving %s%s.\n", fn.FullName(), suffix)
	}
	if fn.Enclosing == nil {
		name := fn.FullName()
		if ext := externals[name]; ext != nil {
			if i.mode&EnableTracing != 0 {
				fmt.Fprintln(os.Stderr, "\t(external)")
			}
			return ext(fn, args)
		}
		if fn.Blocks == nil {
			panic("no code for function: " + name)
		}
	}
	fr := &frame{
		i:      i,
		caller: caller, // currently unused; for unwinding.
		fn:     fn,
		env:    make(map[ssa.Value]value),
		block:  fn.Blocks[0],
		locals: make([]value, len(fn.Locals)),
	}
	for i, l := range fn.Locals {
		fr.locals[i] = zero(l.Type().Deref())
		fr.env[l] = &fr.locals[i]
	}
	for i, p := range fn.Params {
		fr.env[p] = args[i]
	}
	for i, fv := range fn.FreeVars {
		fr.env[fv] = env[i]
	}
	var instr ssa.Instruction

	defer func() {
		if fr.status != stComplete {
			if fr.i.mode&DisableRecover != 0 {
				return // let interpreter crash
			}
			fr.status, fr.panic = stPanic, recover()
		}
		fr.rundefers()
		// Destroy the locals to avoid accidental use after return.
		for i := range fn.Locals {
			fr.locals[i] = bad{}
		}
		if fr.status == stPanic {
			panic(fr.panic) // panic stack is not entirely clean
		}
	}()

	for {
		if i.mode&EnableTracing != 0 {
			fmt.Fprintf(os.Stderr, ".%s:\n", fr.block)
		}
	block:
		for _, instr = range fr.block.Instrs {
			if i.mode&EnableTracing != 0 {
				if v, ok := instr.(ssa.Value); ok {
					fmt.Fprintln(os.Stderr, "\t", v.Name(), "=", instr)
				} else {
					fmt.Fprintln(os.Stderr, "\t", instr)
				}
			}
			switch visitInstr(fr, instr) {
			case kReturn:
				fr.status = stComplete
				return fr.result
			case kNext:
				// no-op
			case kJump:
				break block
			}
		}
	}
	panic("unreachable")
}