Example #1
0
// setGlobal sets the value of a system-initialized global variable.
func setGlobal(i *interpreter, pkg *ssa.Package, name string, v value) {
	if g, ok := i.globals[pkg.Var(name)]; ok {
		*g = v
		return
	}
	panic("no global variable: " + pkg.Object.Path() + "." + name)
}
Example #2
0
func (c *compiler) buildPackageInitData(mainPkg *ssa.Package) gccgoimporter.InitData {
	var inits []gccgoimporter.PackageInit
	for _, imp := range mainPkg.Object.Imports() {
		inits = append(inits, c.InitMap[imp].Inits...)
	}
	sort.Sort(byPriorityThenFunc(inits))

	// Deduplicate init entries. We want to preserve the entry with the highest priority.
	// Normally a package's priorities will be consistent among its dependencies, but it is
	// possible for them to be different. For example, if a standard library test augments a
	// package which is a dependency of 'regexp' (which is imported by every test main package)
	// with additional dependencies, those dependencies may cause the package under test to
	// receive a higher priority than indicated by its init clause in 'regexp'.
	uniqinits := make([]gccgoimporter.PackageInit, len(inits))
	uniqinitpos := len(inits)
	uniqinitnames := make(map[string]struct{})
	for i, _ := range inits {
		init := inits[len(inits)-1-i]
		if _, ok := uniqinitnames[init.InitFunc]; !ok {
			uniqinitnames[init.InitFunc] = struct{}{}
			uniqinitpos--
			uniqinits[uniqinitpos] = init
		}
	}
	uniqinits = uniqinits[uniqinitpos:]

	ourprio := 1
	if len(uniqinits) != 0 {
		ourprio = uniqinits[len(uniqinits)-1].Priority + 1
	}

	if imp := mainPkg.Func("init"); imp != nil {
		impname := c.types.mc.mangleFunctionName(imp)
		uniqinits = append(uniqinits, gccgoimporter.PackageInit{mainPkg.Object.Name(), impname, ourprio})
	}

	return gccgoimporter.InitData{ourprio, uniqinits}
}
Example #3
0
// 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.  sizes is the
// effective type-sizing function for this program.
//
// Interpret returns the exit code of the program: 2 for panic (like
// gc does), or the argument to os.Exit for normal termination.
//
// The SSA program must include the "runtime" package.
//
func Interpret(mainpkg *ssa.Package, mode Mode, sizes types.Sizes, filename string, args []string) (exitCode int) {
	i := &interpreter{
		prog:    mainpkg.Prog,
		globals: make(map[ssa.Value]*value),
		mode:    mode,
		sizes:   sizes,
	}
	runtimePkg := i.prog.ImportedPackage("runtime")
	if runtimePkg == nil {
		panic("ssa.Program doesn't include runtime package")
	}
	i.runtimeErrorString = runtimePkg.Type("errorString").Object().Type()

	initReflect(i)

	i.osArgs = append(i.osArgs, filename)
	for _, arg := range args {
		i.osArgs = append(i.osArgs, arg)
	}

	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":
			setGlobal(i, pkg, "envs", environ)

		case "reflect":
			deleteBodies(pkg, "DeepEqual", "deepValueEqual")

		case "runtime":
			sz := sizes.Sizeof(pkg.Object.Scope().Lookup("MemStats").Type())
			setGlobal(i, pkg, "sizeof_C_MStats", uintptr(sz))
			deleteBodies(pkg, "GOROOT", "gogetenv")
		}
	}

	// 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: %v\n", p, 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
}