interp: limit max instructions per function

builder/build.go

@@ -446,7 +446,7 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 				if pkgInit.IsNil() {
 					panic("init not found for " + pkg.Pkg.Path())
 				}
-				err := interp.RunFunc(pkgInit, config.Options.InterpTimeout, config.DumpSSA())
+				err := interp.RunFunc(pkgInit, config.Options.InterpTimeout, config.Options.InterpMaxDepth, config.Options.InterpMaxInstr, config.DumpSSA())
 				if err != nil {
 					return err
 				}
@@ -1043,7 +1043,7 @@ func createEmbedObjectFile(data, hexSum, sourceFile, sourceDir, tmpdir string, c
 // needed to convert a program to its final form. Some transformations are not
 // optional and must be run as the compiler expects them to run.
 func optimizeProgram(mod llvm.Module, config *compileopts.Config) error {
-	err := interp.Run(mod, config.Options.InterpTimeout, config.DumpSSA())
+	err := interp.Run(mod, config.Options.InterpTimeout, config.Options.InterpMaxDepth, config.Options.InterpMaxInstr, config.DumpSSA())
 	if err != nil {
 		return err
 	}

cgo/cgo.go

@@ -75,10 +75,19 @@ type bitfieldInfo struct {
 }
 
 // cgoAliases list type aliases between Go and C, for types that are equivalent
-// in both languages.
+// in both languages. See addTypeAliases.
 var cgoAliases = map[string]string{
-	"float":  "float32",
+	"C.int8_t":    "int8",
-	"double": "float64",
+	"C.int16_t":   "int16",
+	"C.int32_t":   "int32",
+	"C.int64_t":   "int64",
+	"C.uint8_t":   "uint8",
+	"C.uint16_t":  "uint16",
+	"C.uint32_t":  "uint32",
+	"C.uint64_t":  "uint64",
+	"C.uintptr_t": "uintptr",
+	"C.float":     "float32",
+	"C.double":    "float64",
 }
 
 // builtinAliases are handled specially because they only exist on the Go side
@@ -302,11 +311,10 @@ func Process(files []*ast.File, dir, importPath string, fset *token.FileSet, cfl
 	// Process CGo imports for each file.
 	for i, f := range files {
 		cf := p.newCGoFile(f, i)
-		// These types are aliased with the corresponding types in C. For
+		// Float and double are aliased, meaning that C.float is the same thing
-		// example, float in C is always float32 in Go.
+		// as float32 in Go.
-		for name := range cgoAliases {
+		cf.names["float"] = clangCursor{}
-			cf.names[name] = clangCursor{}
+		cf.names["double"] = clangCursor{}
-		}
 		// Now read all the names (identifies) that C defines in the header
 		// snippet.
 		cf.readNames(p.cgoHeaders[i], cflagsForCGo, filepath.Base(fset.File(f.Pos()).Name()), func(names map[string]clangCursor) {
@@ -1121,7 +1129,9 @@ func (p *cgoPackage) getUnnamedDeclName(prefix string, itf interface{}) string {
 // getASTDeclName will declare the given C AST node (if not already defined) and
 // will return its name, in the form of C.foo.
 func (f *cgoFile) getASTDeclName(name string, found clangCursor, iscall bool) string {
-	if alias := cgoAliases[name]; alias != "" {
+	// Some types are defined in stdint.h and map directly to a particular Go
+	// type.
+	if alias := cgoAliases["C."+name]; alias != "" {
 		return alias
 	}
 	node := f.getASTDeclNode(name, found, iscall)

cgo/testdata/errors.go

@@ -22,12 +22,8 @@ import "C"
 // #warning another warning
 import "C"
 
-// #include <stdint.h>
-import "C"
-
 // Make sure that errors for the following lines won't change with future
 // additions to the CGo preamble.
-//
 //line errors.go:100
 var (
 	// constant too large
@@ -42,8 +38,4 @@ var (
 	_ byte = C.SOME_CONST_3
 
 	_ = C.SOME_CONST_4
-
-	// This must result in a type error. Previously, TinyGo would allow this
-	// code (which is not allowed by upstream Go).
-	_ int8 = C.int8_t(5)
 )

cgo/testdata/errors.out.go

@@ -11,7 +11,6 @@
 //     testdata/errors.go:108: undefined: C.SOME_CONST_1
 //     testdata/errors.go:110: cannot use C.SOME_CONST_3 (untyped int constant 1234) as byte value in variable declaration (overflows)
 //     testdata/errors.go:112: undefined: C.SOME_CONST_4
-//     testdata/errors.go:116: cannot use C.int8_t(5) (constant 5 of type C.schar) as int8 value in variable declaration
 
 package main
 
@@ -59,5 +58,3 @@ type C.struct_point_t struct {
 type C.point_t = C.struct_point_t
 
 const C.SOME_CONST_3 = 1234
-
-type C.int8_t = C.schar

compileopts/options.go

@@ -32,6 +32,8 @@ type Options struct {
 	Serial          string
 	Work            bool // -work flag to print temporary build directory
 	InterpTimeout   time.Duration
+	InterpMaxDepth  int
+	InterpMaxInstr  int
 	PrintIR         bool
 	DumpSSA         bool
 	VerifyIR        bool

interp/errors.go

@@ -19,6 +19,7 @@ var (
 	errUnsupportedRuntimeInst = errors.New("interp: unsupported instruction (to be emitted at runtime)")
 	errMapAlreadyCreated      = errors.New("interp: map already created")
 	errLoopUnrolled           = errors.New("interp: loop unrolled")
+	errDepthExceeded          = errors.New("interp: depth exceeded")
 )
 
 // This is one of the errors that can be returned from toLLVMValue when the
@@ -29,7 +30,7 @@ var errInvalidPtrToIntSize = errors.New("interp: ptrtoint integer size does not
 func isRecoverableError(err error) bool {
 	return err == errIntegerAsPointer || err == errUnsupportedInst ||
 		err == errUnsupportedRuntimeInst || err == errMapAlreadyCreated ||
-		err == errLoopUnrolled
+		err == errLoopUnrolled || err == errDepthExceeded
 }
 
 // ErrorLine is one line in a traceback. The position may be missing.

interp/interp.go

@@ -31,10 +31,12 @@ type runner struct {
 	globals       map[llvm.Value]int       // map from global to index in objects slice
 	start         time.Time
 	timeout       time.Duration
+	maxDepth      int
+	maxInstr      int
 	callsExecuted uint64
 }
 
-func newRunner(mod llvm.Module, timeout time.Duration, debug bool) *runner {
+func newRunner(mod llvm.Module, timeout time.Duration, maxDepth int, maxInstr int, debug bool) *runner {
 	r := runner{
 		mod:           mod,
 		targetData:    llvm.NewTargetData(mod.DataLayout()),
@@ -44,6 +46,8 @@ func newRunner(mod llvm.Module, timeout time.Duration, debug bool) *runner {
 		globals:       make(map[llvm.Value]int),
 		start:         time.Now(),
 		timeout:       timeout,
+		maxDepth:      maxDepth,
+		maxInstr:      maxInstr,
 	}
 	r.pointerSize = uint32(r.targetData.PointerSize())
 	r.i8ptrType = llvm.PointerType(mod.Context().Int8Type(), 0)
@@ -60,8 +64,8 @@ func (r *runner) dispose() {
 
 // Run evaluates runtime.initAll function as much as possible at compile time.
 // Set debug to true if it should print output while running.
-func Run(mod llvm.Module, timeout time.Duration, debug bool) error {
+func Run(mod llvm.Module, timeout time.Duration, maxDepth int, maxInstr int, debug bool) error {
-	r := newRunner(mod, timeout, debug)
+	r := newRunner(mod, timeout, maxDepth, maxInstr, debug)
 	defer r.dispose()
 
 	initAll := mod.NamedFunction("runtime.initAll")
@@ -114,7 +118,7 @@ func Run(mod llvm.Module, timeout time.Duration, debug bool) error {
 		if r.debug {
 			fmt.Fprintln(os.Stderr, "call:", fn.Name())
 		}
-		_, mem, callErr := r.run(r.getFunction(fn), nil, nil, "    ")
+		_, mem, callErr := r.run(r.getFunction(fn), nil, nil, 0, "    ")
 		call.EraseFromParentAsInstruction()
 		if callErr != nil {
 			if isRecoverableError(callErr.Err) {
@@ -201,10 +205,10 @@ func Run(mod llvm.Module, timeout time.Duration, debug bool) error {
 
 // RunFunc evaluates a single package initializer at compile time.
 // Set debug to true if it should print output while running.
-func RunFunc(fn llvm.Value, timeout time.Duration, debug bool) error {
+func RunFunc(fn llvm.Value, timeout time.Duration, maxDepth int, maxInstr int, debug bool) error {
 	// Create and initialize *runner object.
 	mod := fn.GlobalParent()
-	r := newRunner(mod, timeout, debug)
+	r := newRunner(mod, timeout, maxDepth, maxInstr, debug)
 	defer r.dispose()
 	initName := fn.Name()
 	if !strings.HasSuffix(initName, ".init") {
@@ -235,7 +239,7 @@ func RunFunc(fn llvm.Value, timeout time.Duration, debug bool) error {
 	if r.debug {
 		fmt.Fprintln(os.Stderr, "interp:", fn.Name())
 	}
-	_, pkgMem, callErr := r.run(r.getFunction(fn), nil, nil, "    ")
+	_, pkgMem, callErr := r.run(r.getFunction(fn), nil, nil, 0, "    ")
 	if callErr != nil {
 		if isRecoverableError(callErr.Err) {
 			// Could not finish, but could recover from it.

interp/interp_test.go

@@ -53,7 +53,7 @@ func runTest(t *testing.T, pathPrefix string) {
 	defer mod.Dispose()
 
 	// Perform the transform.
-	err = Run(mod, 10*time.Minute, false)
+	err = Run(mod, 10*time.Minute, 10, 0, false)
 	if err != nil {
 		if err, match := err.(*Error); match {
 			println(err.Error())

interp/interpreter.go

@@ -12,7 +12,7 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
-func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent string) (value, memoryView, *Error) {
+func (r *runner) run(fn *function, params []value, parentMem *memoryView, depth int, indent string) (value, memoryView, *Error) {
 	mem := memoryView{r: r, parent: parentMem}
 	locals := make([]value, len(fn.locals))
 	r.callsExecuted++
@@ -33,8 +33,20 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 	lastBB := -1 // last basic block is undefined, only defined after a branch
 	var operands []value
 	startRTInsts := len(mem.instructions)
+	instCount := 0
 	for instIndex := 0; instIndex < len(bb.instructions); instIndex++ {
+		instCount++
+		if r.maxInstr > 0 && instCount > r.maxInstr {
+			fmt.Printf("interp: excess instructions evaluated in %v\n", fn.name)
+			return nil, mem, r.errorAt(fn.blocks[0].instructions[0], errDepthExceeded)
+		}
+
 		if instIndex == 0 {
+			if r.maxDepth > 0 && depth >= r.maxDepth {
+				fmt.Printf("interp: depth exceeded in %v\n", fn.name)
+				return nil, mem, r.errorAt(fn.blocks[0].instructions[0], errDepthExceeded)
+			}
+
 			// This is the start of a new basic block.
 			if len(mem.instructions) != startRTInsts {
 				if _, ok := runtimeBlocks[lastBB]; ok {
@@ -523,7 +535,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 					}
 					fmt.Fprintln(os.Stderr, indent+"call:", callFn.name+"("+strings.Join(argStrings, ", ")+")")
 				}
-				retval, callMem, callErr := r.run(callFn, operands[1:], &mem, indent+"    ")
+				retval, callMem, callErr := r.run(callFn, operands[1:], &mem, depth+1, indent+"    ")
 				if callErr != nil {
 					if isRecoverableError(callErr.Err) {
 						// This error can be recovered by doing the call at

main.go

@@ -1418,6 +1418,8 @@ func main() {
 	serial := flag.String("serial", "", "which serial output to use (none, uart, usb)")
 	work := flag.Bool("work", false, "print the name of the temporary build directory and do not delete this directory on exit")
 	interpTimeout := flag.Duration("interp-timeout", 180*time.Second, "interp optimization pass timeout")
+	interpMaxDepth := flag.Int("interp-maxdepth", 0, "interp optimization max depth (default 0=disabled)")
+	interpMaxInstr := flag.Int("interp-maxinstr", 100_000, "limit interp optimization max instructions (0=disabled)")
 	var tags buildutil.TagsFlag
 	flag.Var(&tags, "tags", "a space-separated list of extra build tags")
 	target := flag.String("target", "", "chip/board name or JSON target specification file")
@@ -1528,6 +1530,8 @@ func main() {
 		Serial:          *serial,
 		Work:            *work,
 		InterpTimeout:   *interpTimeout,
+		InterpMaxDepth:  *interpMaxDepth,
+		InterpMaxInstr:  *interpMaxInstr,
 		PrintIR:         *printIR,
 		DumpSSA:         *dumpSSA,
 		VerifyIR:        *verifyIR,

main_test.go

@@ -296,6 +296,7 @@ func optionsFromTarget(target string, sema chan struct{}) compileopts.Options {
 		Target:         target,
 		Semaphore:      sema,
 		InterpTimeout:  180 * time.Second,
+		InterpMaxDepth: 10,
 		Debug:          true,
 		VerifyIR:       true,
 		Opt:            "z",
@@ -312,6 +313,7 @@ func optionsFromOSARCH(osarch string, sema chan struct{}) compileopts.Options {
 		GOARCH:         parts[1],
 		Semaphore:      sema,
 		InterpTimeout:  180 * time.Second,
+		InterpMaxDepth: 10,
 		Debug:          true,
 		VerifyIR:       true,
 		Opt:            "z",

monitor_test.go

@@ -26,6 +26,7 @@ func TestTraceback(t *testing.T) {
 		GOARCH:         runtime.GOARCH,
 		Opt:            "z",
 		InterpTimeout:  time.Minute,
+		InterpMaxDepth: 10,
 		Debug:          true,
 	})
 	if err != nil {

testdata/cgo/main.go

@@ -52,6 +52,10 @@ func main() {
 	println("static headerfunc:", C.headerfunc_static(5))
 	headerfunc_2()
 
+	// equivalent types
+	var goInt8 int8 = 5
+	var _ C.int8_t = goInt8
+
 	// more globals
 	println("bool:", C.globalBool, C.globalBool2 == true)
 	println("float:", C.globalFloat)