Product config makefiles to Starlark converter

Test: treehugger; internal tests in mk2rbc_test.go
Bug: 172923994
Change-Id: I43120b9c181ef2b8d9453e743233811b0fec268b
diff --git a/mk2rbc/mk2rbc.go b/mk2rbc/mk2rbc.go
new file mode 100644
index 0000000..55a35e9
--- /dev/null
+++ b/mk2rbc/mk2rbc.go
@@ -0,0 +1,1344 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Convert makefile containing device configuration to Starlark file
+// The conversion can handle the following constructs in a makefile:
+//   * comments
+//   * simple variable assignments
+//   * $(call init-product,<file>)
+//   * $(call inherit-product-if-exists
+//   * if directives
+// All other constructs are carried over to the output starlark file as comments.
+//
+package mk2rbc
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"text/scanner"
+
+	mkparser "android/soong/androidmk/parser"
+)
+
+const (
+	baseUri = "//build/make/core:product_config.rbc"
+	// The name of the struct exported by the product_config.rbc
+	// that contains the functions and variables available to
+	// product configuration Starlark files.
+	baseName = "rblf"
+
+	// And here are the functions and variables:
+	cfnGetCfg          = baseName + ".cfg"
+	cfnMain            = baseName + ".product_configuration"
+	cfnPrintVars       = baseName + ".printvars"
+	cfnWarning         = baseName + ".warning"
+	cfnLocalAppend     = baseName + ".local_append"
+	cfnLocalSetDefault = baseName + ".local_set_default"
+	cfnInherit         = baseName + ".inherit"
+	cfnSetListDefault  = baseName + ".setdefault"
+)
+
+const (
+	// Phony makefile functions, they are eventually rewritten
+	// according to knownFunctions map
+	fileExistsPhony     = "$file_exists"
+	wildcardExistsPhony = "$wildcard_exists"
+)
+
+const (
+	callLoadAlways = "inherit-product"
+	callLoadIf     = "inherit-product-if-exists"
+)
+
+var knownFunctions = map[string]struct {
+	// The name of the runtime function this function call in makefiles maps to.
+	// If it starts with !, then this makefile function call is rewritten to
+	// something else.
+	runtimeName string
+	returnType  starlarkType
+}{
+	fileExistsPhony:                       {baseName + ".file_exists", starlarkTypeBool},
+	wildcardExistsPhony:                   {baseName + ".file_wildcard_exists", starlarkTypeBool},
+	"add-to-product-copy-files-if-exists": {baseName + ".copy_if_exists", starlarkTypeList},
+	"addprefix":                           {baseName + ".addprefix", starlarkTypeList},
+	"addsuffix":                           {baseName + ".addsuffix", starlarkTypeList},
+	"enforce-product-packages-exist":      {baseName + ".enforce_product_packages_exist", starlarkTypeVoid},
+	"error":                               {baseName + ".mkerror", starlarkTypeVoid},
+	"findstring":                          {"!findstring", starlarkTypeInt},
+	"find-copy-subdir-files":              {baseName + ".find_and_copy", starlarkTypeList},
+	"filter":                              {baseName + ".filter", starlarkTypeList},
+	"filter-out":                          {baseName + ".filter_out", starlarkTypeList},
+	"info":                                {baseName + ".mkinfo", starlarkTypeVoid},
+	"is-board-platform":                   {"!is-board-platform", starlarkTypeBool},
+	"is-board-platform-in-list":           {"!is-board-platform-in-list", starlarkTypeBool},
+	"is-product-in-list":                  {"!is-product-in-list", starlarkTypeBool},
+	"is-vendor-board-platform":            {"!is-vendor-board-platform", starlarkTypeBool},
+	callLoadAlways:                        {"!inherit-product", starlarkTypeVoid},
+	callLoadIf:                            {"!inherit-product-if-exists", starlarkTypeVoid},
+	"produce_copy_files":                  {baseName + ".produce_copy_files", starlarkTypeList},
+	"require-artifacts-in-path":           {baseName + ".require_artifacts_in_path", starlarkTypeVoid},
+	"require-artifacts-in-path-relaxed":   {baseName + ".require_artifacts_in_path_relaxed", starlarkTypeVoid},
+	// TODO(asmundak): remove it once all calls are removed from configuration makefiles. see b/183161002
+	"shell":    {baseName + ".shell", starlarkTypeString},
+	"strip":    {baseName + ".mkstrip", starlarkTypeString},
+	"subst":    {baseName + ".subst", starlarkTypeString},
+	"warning":  {baseName + ".mkwarning", starlarkTypeVoid},
+	"word":     {baseName + "!word", starlarkTypeString},
+	"wildcard": {baseName + ".expand_wildcard", starlarkTypeList},
+}
+
+var builtinFuncRex = regexp.MustCompile(
+	"^(addprefix|addsuffix|abspath|and|basename|call|dir|error|eval" +
+		"|flavor|foreach|file|filter|filter-out|findstring|firstword|guile" +
+		"|if|info|join|lastword|notdir|or|origin|patsubst|realpath" +
+		"|shell|sort|strip|subst|suffix|value|warning|word|wordlist|words" +
+		"|wildcard)")
+
+// Conversion request parameters
+type Request struct {
+	MkFile             string    // file to convert
+	Reader             io.Reader // if set, read input from this stream instead
+	RootDir            string    // root directory path used to resolve included files
+	OutputSuffix       string    // generated Starlark files suffix
+	OutputDir          string    // if set, root of the output hierarchy
+	ErrorLogger        ErrorMonitorCB
+	TracedVariables    []string // trace assignment to these variables
+	TraceCalls         bool
+	WarnPartialSuccess bool
+}
+
+// An error sink allowing to gather error statistics.
+// NewError is called on every error encountered during processing.
+type ErrorMonitorCB interface {
+	NewError(s string, node mkparser.Node, args ...interface{})
+}
+
+// Derives module name for a given file. It is base name
+// (file name without suffix), with some characters replaced to make it a Starlark identifier
+func moduleNameForFile(mkFile string) string {
+	base := strings.TrimSuffix(filepath.Base(mkFile), filepath.Ext(mkFile))
+	// TODO(asmundak): what else can be in the product file names?
+	return strings.ReplaceAll(base, "-", "_")
+}
+
+func cloneMakeString(mkString *mkparser.MakeString) *mkparser.MakeString {
+	r := &mkparser.MakeString{StringPos: mkString.StringPos}
+	r.Strings = append(r.Strings, mkString.Strings...)
+	r.Variables = append(r.Variables, mkString.Variables...)
+	return r
+}
+
+func isMakeControlFunc(s string) bool {
+	return s == "error" || s == "warning" || s == "info"
+}
+
+// Starlark output generation context
+type generationContext struct {
+	buf          strings.Builder
+	starScript   *StarlarkScript
+	indentLevel  int
+	inAssignment bool
+	tracedCount  int
+}
+
+func NewGenerateContext(ss *StarlarkScript) *generationContext {
+	return &generationContext{starScript: ss}
+}
+
+// emit returns generated script
+func (gctx *generationContext) emit() string {
+	ss := gctx.starScript
+
+	// The emitted code has the following layout:
+	//    <initial comments>
+	//    preamble, i.e.,
+	//      load statement for the runtime support
+	//      load statement for each unique submodule pulled in by this one
+	//    def init(g, handle):
+	//      cfg = rblf.cfg(handle)
+	//      <statements>
+	//      <warning if conversion was not clean>
+
+	iNode := len(ss.nodes)
+	for i, node := range ss.nodes {
+		if _, ok := node.(*commentNode); !ok {
+			iNode = i
+			break
+		}
+		node.emit(gctx)
+	}
+
+	gctx.emitPreamble()
+
+	gctx.newLine()
+	// The arguments passed to the init function are the global dictionary
+	// ('g') and the product configuration dictionary ('cfg')
+	gctx.write("def init(g, handle):")
+	gctx.indentLevel++
+	if gctx.starScript.traceCalls {
+		gctx.newLine()
+		gctx.writef(`print(">%s")`, gctx.starScript.mkFile)
+	}
+	gctx.newLine()
+	gctx.writef("cfg = %s(handle)", cfnGetCfg)
+	for _, node := range ss.nodes[iNode:] {
+		node.emit(gctx)
+	}
+
+	if ss.hasErrors && ss.warnPartialSuccess {
+		gctx.newLine()
+		gctx.writef("%s(%q, %q)", cfnWarning, filepath.Base(ss.mkFile), "partially successful conversion")
+	}
+	if gctx.starScript.traceCalls {
+		gctx.newLine()
+		gctx.writef(`print("<%s")`, gctx.starScript.mkFile)
+	}
+	gctx.indentLevel--
+	gctx.write("\n")
+	return gctx.buf.String()
+}
+
+func (gctx *generationContext) emitPreamble() {
+	gctx.newLine()
+	gctx.writef("load(%q, %q)", baseUri, baseName)
+	// Emit exactly one load statement for each URI.
+	loadedSubConfigs := make(map[string]string)
+	for _, sc := range gctx.starScript.inherited {
+		uri := sc.path
+		if m, ok := loadedSubConfigs[uri]; ok {
+			// No need to emit load statement, but fix module name.
+			sc.moduleLocalName = m
+			continue
+		}
+		if !sc.loadAlways {
+			uri += "|init"
+		}
+		gctx.newLine()
+		gctx.writef("load(%q, %s = \"init\")", uri, sc.entryName())
+		loadedSubConfigs[uri] = sc.moduleLocalName
+	}
+	gctx.write("\n")
+}
+
+func (gctx *generationContext) emitPass() {
+	gctx.newLine()
+	gctx.write("pass")
+}
+
+func (gctx *generationContext) write(ss ...string) {
+	for _, s := range ss {
+		gctx.buf.WriteString(s)
+	}
+}
+
+func (gctx *generationContext) writef(format string, args ...interface{}) {
+	gctx.write(fmt.Sprintf(format, args...))
+}
+
+func (gctx *generationContext) newLine() {
+	if gctx.buf.Len() == 0 {
+		return
+	}
+	gctx.write("\n")
+	gctx.writef("%*s", 2*gctx.indentLevel, "")
+}
+
+type knownVariable struct {
+	name      string
+	class     varClass
+	valueType starlarkType
+}
+
+type knownVariables map[string]knownVariable
+
+func (pcv knownVariables) NewVariable(name string, varClass varClass, valueType starlarkType) {
+	v, exists := pcv[name]
+	if !exists {
+		pcv[name] = knownVariable{name, varClass, valueType}
+		return
+	}
+	// Conflict resolution:
+	//    * config class trumps everything
+	//    * any type trumps unknown type
+	match := varClass == v.class
+	if !match {
+		if varClass == VarClassConfig {
+			v.class = VarClassConfig
+			match = true
+		} else if v.class == VarClassConfig {
+			match = true
+		}
+	}
+	if valueType != v.valueType {
+		if valueType != starlarkTypeUnknown {
+			if v.valueType == starlarkTypeUnknown {
+				v.valueType = valueType
+			} else {
+				match = false
+			}
+		}
+	}
+	if !match {
+		fmt.Fprintf(os.Stderr, "cannot redefine %s as %v/%v (already defined as %v/%v)\n",
+			name, varClass, valueType, v.class, v.valueType)
+	}
+}
+
+// All known product variables.
+var KnownVariables = make(knownVariables)
+
+func init() {
+	for _, kv := range []string{
+		// Kernel-related variables that we know are lists.
+		"BOARD_VENDOR_KERNEL_MODULES",
+		"BOARD_VENDOR_RAMDISK_KERNEL_MODULES",
+		"BOARD_VENDOR_RAMDISK_KERNEL_MODULES_LOAD",
+		"BOARD_RECOVERY_KERNEL_MODULES",
+		// Other variables we knwo are lists
+		"ART_APEX_JARS",
+	} {
+		KnownVariables.NewVariable(kv, VarClassSoong, starlarkTypeList)
+	}
+}
+
+type nodeReceiver interface {
+	newNode(node starlarkNode)
+}
+
+// Information about the generated Starlark script.
+type StarlarkScript struct {
+	mkFile             string
+	moduleName         string
+	mkPos              scanner.Position
+	nodes              []starlarkNode
+	inherited          []*inheritedModule
+	hasErrors          bool
+	topDir             string
+	traceCalls         bool // print enter/exit each init function
+	warnPartialSuccess bool
+}
+
+func (ss *StarlarkScript) newNode(node starlarkNode) {
+	ss.nodes = append(ss.nodes, node)
+}
+
+// varAssignmentScope points to the last assignment for each variable
+// in the current block. It is used during the parsing to chain
+// the assignments to a variable together.
+type varAssignmentScope struct {
+	outer *varAssignmentScope
+	vars  map[string]*assignmentNode
+}
+
+// parseContext holds the script we are generating and all the ephemeral data
+// needed during the parsing.
+type parseContext struct {
+	script           *StarlarkScript
+	nodes            []mkparser.Node // Makefile as parsed by mkparser
+	currentNodeIndex int             // Node in it we are processing
+	ifNestLevel      int
+	moduleNameCount  map[string]int // count of imported modules with given basename
+	fatalError       error
+	builtinMakeVars  map[string]starlarkExpr
+	outputSuffix     string
+	errorLogger      ErrorMonitorCB
+	tracedVariables  map[string]bool // variables to be traced in the generated script
+	variables        map[string]variable
+	varAssignments   *varAssignmentScope
+	receiver         nodeReceiver // receptacle for the generated starlarkNode's
+	receiverStack    []nodeReceiver
+	outputDir        string
+}
+
+func newParseContext(ss *StarlarkScript, nodes []mkparser.Node) *parseContext {
+	predefined := []struct{ name, value string }{
+		{"SRC_TARGET_DIR", filepath.Join("build", "make", "target")},
+		{"LOCAL_PATH", filepath.Dir(ss.mkFile)},
+		{"TOPDIR", ss.topDir},
+		// TODO(asmundak): maybe read it from build/make/core/envsetup.mk?
+		{"TARGET_COPY_OUT_SYSTEM", "system"},
+		{"TARGET_COPY_OUT_SYSTEM_OTHER", "system_other"},
+		{"TARGET_COPY_OUT_DATA", "data"},
+		{"TARGET_COPY_OUT_ASAN", filepath.Join("data", "asan")},
+		{"TARGET_COPY_OUT_OEM", "oem"},
+		{"TARGET_COPY_OUT_RAMDISK", "ramdisk"},
+		{"TARGET_COPY_OUT_DEBUG_RAMDISK", "debug_ramdisk"},
+		{"TARGET_COPY_OUT_VENDOR_DEBUG_RAMDISK", "vendor_debug_ramdisk"},
+		{"TARGET_COPY_OUT_TEST_HARNESS_RAMDISK", "test_harness_ramdisk"},
+		{"TARGET_COPY_OUT_ROOT", "root"},
+		{"TARGET_COPY_OUT_RECOVERY", "recovery"},
+		{"TARGET_COPY_OUT_VENDOR", "||VENDOR-PATH-PH||"},
+		{"TARGET_COPY_OUT_VENDOR_RAMDISK", "vendor_ramdisk"},
+		{"TARGET_COPY_OUT_PRODUCT", "||PRODUCT-PATH-PH||"},
+		{"TARGET_COPY_OUT_PRODUCT_SERVICES", "||PRODUCT-PATH-PH||"},
+		{"TARGET_COPY_OUT_SYSTEM_EXT", "||SYSTEM_EXT-PATH-PH||"},
+		{"TARGET_COPY_OUT_ODM", "||ODM-PATH-PH||"},
+		{"TARGET_COPY_OUT_VENDOR_DLKM", "||VENDOR_DLKM-PATH-PH||"},
+		{"TARGET_COPY_OUT_ODM_DLKM", "||ODM_DLKM-PATH-PH||"},
+		// TODO(asmundak): to process internal config files, we need the following variables:
+		//    BOARD_CONFIG_VENDOR_PATH
+		//    TARGET_VENDOR
+		//    target_base_product
+		//
+
+		// the following utility variables are set in build/make/common/core.mk:
+		{"empty", ""},
+		{"space", " "},
+		{"comma", ","},
+		{"newline", "\n"},
+		{"pound", "#"},
+		{"backslash", "\\"},
+	}
+	ctx := &parseContext{
+		script:           ss,
+		nodes:            nodes,
+		currentNodeIndex: 0,
+		ifNestLevel:      0,
+		moduleNameCount:  make(map[string]int),
+		builtinMakeVars:  map[string]starlarkExpr{},
+		variables:        make(map[string]variable),
+	}
+	ctx.pushVarAssignments()
+	for _, item := range predefined {
+		ctx.variables[item.name] = &predefinedVariable{
+			baseVariable: baseVariable{nam: item.name, typ: starlarkTypeString},
+			value:        &stringLiteralExpr{item.value},
+		}
+	}
+
+	return ctx
+}
+
+func (ctx *parseContext) lastAssignment(name string) *assignmentNode {
+	for va := ctx.varAssignments; va != nil; va = va.outer {
+		if v, ok := va.vars[name]; ok {
+			return v
+		}
+	}
+	return nil
+}
+
+func (ctx *parseContext) setLastAssignment(name string, asgn *assignmentNode) {
+	ctx.varAssignments.vars[name] = asgn
+}
+
+func (ctx *parseContext) pushVarAssignments() {
+	va := &varAssignmentScope{
+		outer: ctx.varAssignments,
+		vars:  make(map[string]*assignmentNode),
+	}
+	ctx.varAssignments = va
+}
+
+func (ctx *parseContext) popVarAssignments() {
+	ctx.varAssignments = ctx.varAssignments.outer
+}
+
+func (ctx *parseContext) pushReceiver(rcv nodeReceiver) {
+	ctx.receiverStack = append(ctx.receiverStack, ctx.receiver)
+	ctx.receiver = rcv
+}
+
+func (ctx *parseContext) popReceiver() {
+	last := len(ctx.receiverStack) - 1
+	if last < 0 {
+		panic(fmt.Errorf("popReceiver: receiver stack empty"))
+	}
+	ctx.receiver = ctx.receiverStack[last]
+	ctx.receiverStack = ctx.receiverStack[0:last]
+}
+
+func (ctx *parseContext) hasNodes() bool {
+	return ctx.currentNodeIndex < len(ctx.nodes)
+}
+
+func (ctx *parseContext) getNode() mkparser.Node {
+	if !ctx.hasNodes() {
+		return nil
+	}
+	node := ctx.nodes[ctx.currentNodeIndex]
+	ctx.currentNodeIndex++
+	return node
+}
+
+func (ctx *parseContext) backNode() {
+	if ctx.currentNodeIndex <= 0 {
+		panic("Cannot back off")
+	}
+	ctx.currentNodeIndex--
+}
+
+func (ctx *parseContext) handleAssignment(a *mkparser.Assignment) {
+	// Handle only simple variables
+	if !a.Name.Const() {
+		ctx.errorf(a, "Only simple variables are handled")
+		return
+	}
+	name := a.Name.Strings[0]
+	lhs := ctx.addVariable(name)
+	if lhs == nil {
+		ctx.errorf(a, "unknown variable %s", name)
+		return
+	}
+	_, isTraced := ctx.tracedVariables[name]
+	asgn := &assignmentNode{lhs: lhs, mkValue: a.Value, isTraced: isTraced}
+	if lhs.valueType() == starlarkTypeUnknown {
+		// Try to divine variable type from the RHS
+		asgn.value = ctx.parseMakeString(a, a.Value)
+		if xBad, ok := asgn.value.(*badExpr); ok {
+			ctx.wrapBadExpr(xBad)
+			return
+		}
+		inferred_type := asgn.value.typ()
+		if inferred_type != starlarkTypeUnknown {
+			if ogv, ok := lhs.(*otherGlobalVariable); ok {
+				ogv.typ = inferred_type
+			} else if pcv, ok := lhs.(*productConfigVariable); ok {
+				pcv.typ = inferred_type
+			} else {
+				panic(fmt.Errorf("cannot assign new type to a variable %s, its flavor is %T", lhs.name(), lhs))
+			}
+		}
+	}
+	if lhs.valueType() == starlarkTypeList {
+		xConcat := ctx.buildConcatExpr(a)
+		if xConcat == nil {
+			return
+		}
+		switch len(xConcat.items) {
+		case 0:
+			asgn.value = &listExpr{}
+		case 1:
+			asgn.value = xConcat.items[0]
+		default:
+			asgn.value = xConcat
+		}
+	} else {
+		asgn.value = ctx.parseMakeString(a, a.Value)
+		if xBad, ok := asgn.value.(*badExpr); ok {
+			ctx.wrapBadExpr(xBad)
+			return
+		}
+	}
+
+	// TODO(asmundak): move evaluation to a separate pass
+	asgn.value, _ = asgn.value.eval(ctx.builtinMakeVars)
+
+	asgn.previous = ctx.lastAssignment(name)
+	ctx.setLastAssignment(name, asgn)
+	switch a.Type {
+	case "=", ":=":
+		asgn.flavor = asgnSet
+	case "+=":
+		if asgn.previous == nil && !asgn.lhs.isPreset() {
+			asgn.flavor = asgnMaybeAppend
+		} else {
+			asgn.flavor = asgnAppend
+		}
+	case "?=":
+		asgn.flavor = asgnMaybeSet
+	default:
+		panic(fmt.Errorf("unexpected assignment type %s", a.Type))
+	}
+
+	ctx.receiver.newNode(asgn)
+}
+
+func (ctx *parseContext) buildConcatExpr(a *mkparser.Assignment) *concatExpr {
+	xConcat := &concatExpr{}
+	var xItemList *listExpr
+	addToItemList := func(x ...starlarkExpr) {
+		if xItemList == nil {
+			xItemList = &listExpr{[]starlarkExpr{}}
+		}
+		xItemList.items = append(xItemList.items, x...)
+	}
+	finishItemList := func() {
+		if xItemList != nil {
+			xConcat.items = append(xConcat.items, xItemList)
+			xItemList = nil
+		}
+	}
+
+	items := a.Value.Words()
+	for _, item := range items {
+		// A function call in RHS is supposed to return a list, all other item
+		// expressions return individual elements.
+		switch x := ctx.parseMakeString(a, item).(type) {
+		case *badExpr:
+			ctx.wrapBadExpr(x)
+			return nil
+		case *stringLiteralExpr:
+			addToItemList(maybeConvertToStringList(x).(*listExpr).items...)
+		default:
+			switch x.typ() {
+			case starlarkTypeList:
+				finishItemList()
+				xConcat.items = append(xConcat.items, x)
+			case starlarkTypeString:
+				finishItemList()
+				xConcat.items = append(xConcat.items, &callExpr{
+					object:     x,
+					name:       "split",
+					args:       nil,
+					returnType: starlarkTypeList,
+				})
+			default:
+				addToItemList(x)
+			}
+		}
+	}
+	if xItemList != nil {
+		xConcat.items = append(xConcat.items, xItemList)
+	}
+	return xConcat
+}
+
+func (ctx *parseContext) newInheritedModule(v mkparser.Node, pathExpr starlarkExpr, loadAlways bool) *inheritedModule {
+	var path string
+	x, _ := pathExpr.eval(ctx.builtinMakeVars)
+	s, ok := x.(*stringLiteralExpr)
+	if !ok {
+		ctx.errorf(v, "inherit-product/include argument is too complex")
+		return nil
+	}
+
+	path = s.literal
+	moduleName := moduleNameForFile(path)
+	moduleLocalName := "_" + moduleName
+	n, found := ctx.moduleNameCount[moduleName]
+	if found {
+		moduleLocalName += fmt.Sprintf("%d", n)
+	}
+	ctx.moduleNameCount[moduleName] = n + 1
+	ln := &inheritedModule{
+		path:            ctx.loadedModulePath(path),
+		originalPath:    path,
+		moduleName:      moduleName,
+		moduleLocalName: moduleLocalName,
+		loadAlways:      loadAlways,
+	}
+	ctx.script.inherited = append(ctx.script.inherited, ln)
+	return ln
+}
+
+func (ctx *parseContext) handleInheritModule(v mkparser.Node, pathExpr starlarkExpr, loadAlways bool) {
+	if im := ctx.newInheritedModule(v, pathExpr, loadAlways); im != nil {
+		ctx.receiver.newNode(&inheritNode{im})
+	}
+}
+
+func (ctx *parseContext) handleInclude(v mkparser.Node, pathExpr starlarkExpr, loadAlways bool) {
+	if ln := ctx.newInheritedModule(v, pathExpr, loadAlways); ln != nil {
+		ctx.receiver.newNode(&includeNode{ln})
+	}
+}
+
+func (ctx *parseContext) handleVariable(v *mkparser.Variable) {
+	// Handle:
+	//   $(call inherit-product,...)
+	//   $(call inherit-product-if-exists,...)
+	//   $(info xxx)
+	//   $(warning xxx)
+	//   $(error xxx)
+	expr := ctx.parseReference(v, v.Name)
+	switch x := expr.(type) {
+	case *callExpr:
+		if x.name == callLoadAlways || x.name == callLoadIf {
+			ctx.handleInheritModule(v, x.args[0], x.name == callLoadAlways)
+		} else if isMakeControlFunc(x.name) {
+			// File name is the first argument
+			args := []starlarkExpr{
+				&stringLiteralExpr{ctx.script.mkFile},
+				x.args[0],
+			}
+			ctx.receiver.newNode(&exprNode{
+				&callExpr{name: x.name, args: args, returnType: starlarkTypeUnknown},
+			})
+		} else {
+			ctx.receiver.newNode(&exprNode{expr})
+		}
+	case *badExpr:
+		ctx.wrapBadExpr(x)
+		return
+	default:
+		ctx.errorf(v, "cannot handle %s", v.Dump())
+		return
+	}
+}
+
+func (ctx *parseContext) handleDefine(directive *mkparser.Directive) {
+	tokens := strings.Fields(directive.Args.Strings[0])
+	ctx.errorf(directive, "define is not supported: %s", tokens[0])
+}
+
+func (ctx *parseContext) handleIfBlock(ifDirective *mkparser.Directive) {
+	ssSwitch := &switchNode{}
+	ctx.pushReceiver(ssSwitch)
+	for ctx.processBranch(ifDirective); ctx.hasNodes() && ctx.fatalError == nil; {
+		node := ctx.getNode()
+		switch x := node.(type) {
+		case *mkparser.Directive:
+			switch x.Name {
+			case "else", "elifdef", "elifndef", "elifeq", "elifneq":
+				ctx.processBranch(x)
+			case "endif":
+				ctx.popReceiver()
+				ctx.receiver.newNode(ssSwitch)
+				return
+			default:
+				ctx.errorf(node, "unexpected directive %s", x.Name)
+			}
+		default:
+			ctx.errorf(ifDirective, "unexpected statement")
+		}
+	}
+	if ctx.fatalError == nil {
+		ctx.fatalError = fmt.Errorf("no matching endif for %s", ifDirective.Dump())
+	}
+	ctx.popReceiver()
+}
+
+// processBranch processes a single branch (if/elseif/else) until the next directive
+// on the same level.
+func (ctx *parseContext) processBranch(check *mkparser.Directive) {
+	block := switchCase{gate: ctx.parseCondition(check)}
+	defer func() {
+		ctx.popVarAssignments()
+		ctx.ifNestLevel--
+
+	}()
+	ctx.pushVarAssignments()
+	ctx.ifNestLevel++
+
+	ctx.pushReceiver(&block)
+	for ctx.hasNodes() {
+		node := ctx.getNode()
+		if ctx.handleSimpleStatement(node) {
+			continue
+		}
+		switch d := node.(type) {
+		case *mkparser.Directive:
+			switch d.Name {
+			case "else", "elifdef", "elifndef", "elifeq", "elifneq", "endif":
+				ctx.popReceiver()
+				ctx.receiver.newNode(&block)
+				ctx.backNode()
+				return
+			case "ifdef", "ifndef", "ifeq", "ifneq":
+				ctx.handleIfBlock(d)
+			default:
+				ctx.errorf(d, "unexpected directive %s", d.Name)
+			}
+		default:
+			ctx.errorf(node, "unexpected statement")
+		}
+	}
+	ctx.fatalError = fmt.Errorf("no matching endif for %s", check.Dump())
+	ctx.popReceiver()
+}
+
+func (ctx *parseContext) newIfDefinedNode(check *mkparser.Directive) (starlarkExpr, bool) {
+	if !check.Args.Const() {
+		return ctx.newBadExpr(check, "ifdef variable ref too complex: %s", check.Args.Dump()), false
+	}
+	v := ctx.addVariable(check.Args.Strings[0])
+	return &variableDefinedExpr{v}, true
+}
+
+func (ctx *parseContext) parseCondition(check *mkparser.Directive) starlarkNode {
+	switch check.Name {
+	case "ifdef", "ifndef", "elifdef", "elifndef":
+		v, ok := ctx.newIfDefinedNode(check)
+		if ok && strings.HasSuffix(check.Name, "ndef") {
+			v = &notExpr{v}
+		}
+		return &ifNode{
+			isElif: strings.HasPrefix(check.Name, "elif"),
+			expr:   v,
+		}
+	case "ifeq", "ifneq", "elifeq", "elifneq":
+		return &ifNode{
+			isElif: strings.HasPrefix(check.Name, "elif"),
+			expr:   ctx.parseCompare(check),
+		}
+	case "else":
+		return &elseNode{}
+	default:
+		panic(fmt.Errorf("%s: unknown directive: %s", ctx.script.mkFile, check.Dump()))
+	}
+}
+
+func (ctx *parseContext) newBadExpr(node mkparser.Node, text string, args ...interface{}) starlarkExpr {
+	message := fmt.Sprintf(text, args...)
+	if ctx.errorLogger != nil {
+		ctx.errorLogger.NewError(text, node, args)
+	}
+	ctx.script.hasErrors = true
+	return &badExpr{node, message}
+}
+
+func (ctx *parseContext) parseCompare(cond *mkparser.Directive) starlarkExpr {
+	// Strip outer parentheses
+	mkArg := cloneMakeString(cond.Args)
+	mkArg.Strings[0] = strings.TrimLeft(mkArg.Strings[0], "( ")
+	n := len(mkArg.Strings)
+	mkArg.Strings[n-1] = strings.TrimRight(mkArg.Strings[n-1], ") ")
+	args := mkArg.Split(",")
+	// TODO(asmundak): handle the case where the arguments are in quotes and space-separated
+	if len(args) != 2 {
+		return ctx.newBadExpr(cond, "ifeq/ifneq len(args) != 2 %s", cond.Dump())
+	}
+	args[0].TrimRightSpaces()
+	args[1].TrimLeftSpaces()
+
+	isEq := !strings.HasSuffix(cond.Name, "neq")
+	switch xLeft := ctx.parseMakeString(cond, args[0]).(type) {
+	case *stringLiteralExpr, *variableRefExpr:
+		switch xRight := ctx.parseMakeString(cond, args[1]).(type) {
+		case *stringLiteralExpr, *variableRefExpr:
+			return &eqExpr{left: xLeft, right: xRight, isEq: isEq}
+		case *badExpr:
+			return xRight
+		default:
+			expr, ok := ctx.parseCheckFunctionCallResult(cond, xLeft, args[1])
+			if ok {
+				return expr
+			}
+			return ctx.newBadExpr(cond, "right operand is too complex: %s", args[1].Dump())
+		}
+	case *badExpr:
+		return xLeft
+	default:
+		switch xRight := ctx.parseMakeString(cond, args[1]).(type) {
+		case *stringLiteralExpr, *variableRefExpr:
+			expr, ok := ctx.parseCheckFunctionCallResult(cond, xRight, args[0])
+			if ok {
+				return expr
+			}
+			return ctx.newBadExpr(cond, "left operand is too complex: %s", args[0].Dump())
+		case *badExpr:
+			return xRight
+		default:
+			return ctx.newBadExpr(cond, "operands are too complex: (%s,%s)", args[0].Dump(), args[1].Dump())
+		}
+	}
+}
+
+func (ctx *parseContext) parseCheckFunctionCallResult(directive *mkparser.Directive, xValue starlarkExpr,
+	varArg *mkparser.MakeString) (starlarkExpr, bool) {
+	mkSingleVar, ok := varArg.SingleVariable()
+	if !ok {
+		return nil, false
+	}
+	expr := ctx.parseReference(directive, mkSingleVar)
+	negate := strings.HasSuffix(directive.Name, "neq")
+	checkIsSomethingFunction := func(xCall *callExpr) starlarkExpr {
+		s, ok := maybeString(xValue)
+		if !ok || s != "true" {
+			return ctx.newBadExpr(directive,
+				fmt.Sprintf("the result of %s can be compared only to 'true'", xCall.name))
+		}
+		if len(xCall.args) < 1 {
+			return ctx.newBadExpr(directive, "%s requires an argument", xCall.name)
+		}
+		return nil
+	}
+	switch x := expr.(type) {
+	case *callExpr:
+		switch x.name {
+		case "filter":
+			return ctx.parseCompareFilterFuncResult(directive, x, xValue, !negate), true
+		case "filter-out":
+			return ctx.parseCompareFilterFuncResult(directive, x, xValue, negate), true
+		case "wildcard":
+			return ctx.parseCompareWildcardFuncResult(directive, x, xValue, negate), true
+		case "findstring":
+			return ctx.parseCheckFindstringFuncResult(directive, x, xValue, negate), true
+		case "strip":
+			return ctx.parseCompareStripFuncResult(directive, x, xValue, negate), true
+		case "is-board-platform":
+			if xBad := checkIsSomethingFunction(x); xBad != nil {
+				return xBad, true
+			}
+			return &eqExpr{
+				left:  &variableRefExpr{ctx.addVariable("TARGET_BOARD_PLATFORM"), false},
+				right: x.args[0],
+				isEq:  !negate,
+			}, true
+		case "is-board-platform-in-list":
+			if xBad := checkIsSomethingFunction(x); xBad != nil {
+				return xBad, true
+			}
+			return &inExpr{
+				expr:  &variableRefExpr{ctx.addVariable("TARGET_BOARD_PLATFORM"), false},
+				list:  maybeConvertToStringList(x.args[0]),
+				isNot: negate,
+			}, true
+		case "is-product-in-list":
+			if xBad := checkIsSomethingFunction(x); xBad != nil {
+				return xBad, true
+			}
+			return &inExpr{
+				expr:  &variableRefExpr{ctx.addVariable("TARGET_PRODUCT"), true},
+				list:  maybeConvertToStringList(x.args[0]),
+				isNot: negate,
+			}, true
+		case "is-vendor-board-platform":
+			if xBad := checkIsSomethingFunction(x); xBad != nil {
+				return xBad, true
+			}
+			s, ok := maybeString(x.args[0])
+			if !ok {
+				return ctx.newBadExpr(directive, "cannot handle non-constant argument to is-vendor-board-platform"), true
+			}
+			return &inExpr{
+				expr:  &variableRefExpr{ctx.addVariable("TARGET_BOARD_PLATFORM"), false},
+				list:  &variableRefExpr{ctx.addVariable(s + "_BOARD_PLATFORMS"), true},
+				isNot: negate,
+			}, true
+		default:
+			return ctx.newBadExpr(directive, "Unknown function in ifeq: %s", x.name), true
+		}
+	case *badExpr:
+		return x, true
+	default:
+		return nil, false
+	}
+}
+
+func (ctx *parseContext) parseCompareFilterFuncResult(cond *mkparser.Directive,
+	filterFuncCall *callExpr, xValue starlarkExpr, negate bool) starlarkExpr {
+	// We handle:
+	// *  ifeq/ifneq (,$(filter v1 v2 ..., $(VAR)) becomes if VAR not in/in ["v1", "v2", ...]
+	// *  ifeq/ifneq (,$(filter $(VAR), v1 v2 ...) becomes if VAR not in/in ["v1", "v2", ...]
+	// *  ifeq/ifneq ($(VAR),$(filter $(VAR), v1 v2 ...) becomes if VAR in/not in ["v1", "v2"]
+	// TODO(Asmundak): check the last case works for filter-out, too.
+	xPattern := filterFuncCall.args[0]
+	xText := filterFuncCall.args[1]
+	var xInList *stringLiteralExpr
+	var xVar starlarkExpr
+	var ok bool
+	switch x := xValue.(type) {
+	case *stringLiteralExpr:
+		if x.literal != "" {
+			return ctx.newBadExpr(cond, "filter comparison to non-empty value: %s", xValue)
+		}
+		// Either pattern or text should be const, and the
+		// non-const one should be varRefExpr
+		if xInList, ok = xPattern.(*stringLiteralExpr); ok {
+			xVar = xText
+		} else if xInList, ok = xText.(*stringLiteralExpr); ok {
+			xVar = xPattern
+		}
+	case *variableRefExpr:
+		if v, ok := xPattern.(*variableRefExpr); ok {
+			if xInList, ok = xText.(*stringLiteralExpr); ok && v.ref.name() == x.ref.name() {
+				// ifeq/ifneq ($(VAR),$(filter $(VAR), v1 v2 ...), flip negate,
+				// it's the opposite to what is done when comparing to empty.
+				xVar = xPattern
+				negate = !negate
+			}
+		}
+	}
+	if xVar != nil && xInList != nil {
+		if _, ok := xVar.(*variableRefExpr); ok {
+			slExpr := newStringListExpr(strings.Fields(xInList.literal))
+			// Generate simpler code for the common cases:
+			if xVar.typ() == starlarkTypeList {
+				if len(slExpr.items) == 1 {
+					// Checking that a string belongs to list
+					return &inExpr{isNot: negate, list: xVar, expr: slExpr.items[0]}
+				} else {
+					// TODO(asmundak):
+					panic("TBD")
+				}
+			}
+			return &inExpr{isNot: negate, list: newStringListExpr(strings.Fields(xInList.literal)), expr: xVar}
+		}
+	}
+	return ctx.newBadExpr(cond, "filter arguments are too complex: %s", cond.Dump())
+}
+
+func (ctx *parseContext) parseCompareWildcardFuncResult(directive *mkparser.Directive,
+	xCall *callExpr, xValue starlarkExpr, negate bool) starlarkExpr {
+	if x, ok := xValue.(*stringLiteralExpr); !ok || x.literal != "" {
+		return ctx.newBadExpr(directive, "wildcard result can be compared only to empty: %s", xValue)
+	}
+	callFunc := wildcardExistsPhony
+	if s, ok := xCall.args[0].(*stringLiteralExpr); ok && !strings.ContainsAny(s.literal, "*?{[") {
+		callFunc = fileExistsPhony
+	}
+	var cc starlarkExpr = &callExpr{name: callFunc, args: xCall.args, returnType: starlarkTypeBool}
+	if !negate {
+		cc = &notExpr{cc}
+	}
+	return cc
+}
+
+func (ctx *parseContext) parseCheckFindstringFuncResult(directive *mkparser.Directive,
+	xCall *callExpr, xValue starlarkExpr, negate bool) starlarkExpr {
+	if x, ok := xValue.(*stringLiteralExpr); !ok || x.literal != "" {
+		return ctx.newBadExpr(directive, "findstring result can be compared only to empty: %s", xValue)
+	}
+	return &eqExpr{
+		left: &callExpr{
+			object:     xCall.args[1],
+			name:       "find",
+			args:       []starlarkExpr{xCall.args[0]},
+			returnType: starlarkTypeInt,
+		},
+		right: &intLiteralExpr{-1},
+		isEq:  !negate,
+	}
+}
+
+func (ctx *parseContext) parseCompareStripFuncResult(directive *mkparser.Directive,
+	xCall *callExpr, xValue starlarkExpr, negate bool) starlarkExpr {
+	if _, ok := xValue.(*stringLiteralExpr); !ok {
+		return ctx.newBadExpr(directive, "strip result can be compared only to string: %s", xValue)
+	}
+	return &eqExpr{
+		left: &callExpr{
+			name:       "strip",
+			args:       xCall.args,
+			returnType: starlarkTypeString,
+		},
+		right: xValue, isEq: !negate}
+}
+
+// parses $(...), returning an expression
+func (ctx *parseContext) parseReference(node mkparser.Node, ref *mkparser.MakeString) starlarkExpr {
+	ref.TrimLeftSpaces()
+	ref.TrimRightSpaces()
+	refDump := ref.Dump()
+
+	// Handle only the case where the first (or only) word is constant
+	words := ref.SplitN(" ", 2)
+	if !words[0].Const() {
+		return ctx.newBadExpr(node, "reference is too complex: %s", refDump)
+	}
+
+	// If it is a single word, it can be a simple variable
+	// reference or a function call
+	if len(words) == 1 {
+		if isMakeControlFunc(refDump) || refDump == "shell" {
+			return &callExpr{
+				name:       refDump,
+				args:       []starlarkExpr{&stringLiteralExpr{""}},
+				returnType: starlarkTypeUnknown,
+			}
+		}
+		if v := ctx.addVariable(refDump); v != nil {
+			return &variableRefExpr{v, ctx.lastAssignment(v.name()) != nil}
+		}
+		return ctx.newBadExpr(node, "unknown variable %s", refDump)
+	}
+
+	expr := &callExpr{name: words[0].Dump(), returnType: starlarkTypeUnknown}
+	args := words[1]
+	args.TrimLeftSpaces()
+	// Make control functions and shell need special treatment as everything
+	// after the name is a single text argument
+	if isMakeControlFunc(expr.name) || expr.name == "shell" {
+		x := ctx.parseMakeString(node, args)
+		if xBad, ok := x.(*badExpr); ok {
+			return xBad
+		}
+		expr.args = []starlarkExpr{x}
+		return expr
+	}
+	if expr.name == "call" {
+		words = args.SplitN(",", 2)
+		if words[0].Empty() || !words[0].Const() {
+			return ctx.newBadExpr(nil, "cannot handle %s", refDump)
+		}
+		expr.name = words[0].Dump()
+		if len(words) < 2 {
+			return expr
+		}
+		args = words[1]
+	}
+	if kf, found := knownFunctions[expr.name]; found {
+		expr.returnType = kf.returnType
+	} else {
+		return ctx.newBadExpr(node, "cannot handle invoking %s", expr.name)
+	}
+	switch expr.name {
+	case "word":
+		return ctx.parseWordFunc(node, args)
+	case "subst":
+		return ctx.parseSubstFunc(node, args)
+	default:
+		for _, arg := range args.Split(",") {
+			arg.TrimLeftSpaces()
+			arg.TrimRightSpaces()
+			x := ctx.parseMakeString(node, arg)
+			if xBad, ok := x.(*badExpr); ok {
+				return xBad
+			}
+			expr.args = append(expr.args, x)
+		}
+	}
+	return expr
+}
+
+func (ctx *parseContext) parseSubstFunc(node mkparser.Node, args *mkparser.MakeString) starlarkExpr {
+	words := args.Split(",")
+	if len(words) != 3 {
+		return ctx.newBadExpr(node, "subst function should have 3 arguments")
+	}
+	if !words[0].Const() || !words[1].Const() {
+		return ctx.newBadExpr(node, "subst function's from and to arguments should be constant")
+	}
+	from := words[0].Strings[0]
+	to := words[1].Strings[0]
+	words[2].TrimLeftSpaces()
+	words[2].TrimRightSpaces()
+	obj := ctx.parseMakeString(node, words[2])
+	return &callExpr{
+		object:     obj,
+		name:       "replace",
+		args:       []starlarkExpr{&stringLiteralExpr{from}, &stringLiteralExpr{to}},
+		returnType: starlarkTypeString,
+	}
+}
+
+func (ctx *parseContext) parseWordFunc(node mkparser.Node, args *mkparser.MakeString) starlarkExpr {
+	words := args.Split(",")
+	if len(words) != 2 {
+		return ctx.newBadExpr(node, "word function should have 2 arguments")
+	}
+	var index uint64 = 0
+	if words[0].Const() {
+		index, _ = strconv.ParseUint(strings.TrimSpace(words[0].Strings[0]), 10, 64)
+	}
+	if index < 1 {
+		return ctx.newBadExpr(node, "word index should be constant positive integer")
+	}
+	words[1].TrimLeftSpaces()
+	words[1].TrimRightSpaces()
+	array := ctx.parseMakeString(node, words[1])
+	if xBad, ok := array.(*badExpr); ok {
+		return xBad
+	}
+	if array.typ() != starlarkTypeList {
+		array = &callExpr{object: array, name: "split", returnType: starlarkTypeList}
+	}
+	return indexExpr{array, &intLiteralExpr{int(index - 1)}}
+}
+
+func (ctx *parseContext) parseMakeString(node mkparser.Node, mk *mkparser.MakeString) starlarkExpr {
+	if mk.Const() {
+		return &stringLiteralExpr{mk.Dump()}
+	}
+	if mkRef, ok := mk.SingleVariable(); ok {
+		return ctx.parseReference(node, mkRef)
+	}
+	// If we reached here, it's neither string literal nor a simple variable,
+	// we need a full-blown interpolation node that will generate
+	// "a%b%c" % (X, Y) for a$(X)b$(Y)c
+	xInterp := &interpolateExpr{args: make([]starlarkExpr, len(mk.Variables))}
+	for i, ref := range mk.Variables {
+		arg := ctx.parseReference(node, ref.Name)
+		if x, ok := arg.(*badExpr); ok {
+			return x
+		}
+		xInterp.args[i] = arg
+	}
+	xInterp.chunks = append(xInterp.chunks, mk.Strings...)
+	return xInterp
+}
+
+// Handles the statements whose treatment is the same in all contexts: comment,
+// assignment, variable (which is a macro call in reality) and all constructs that
+// do not handle in any context ('define directive and any unrecognized stuff).
+// Return true if we handled it.
+func (ctx *parseContext) handleSimpleStatement(node mkparser.Node) bool {
+	handled := true
+	switch x := node.(type) {
+	case *mkparser.Comment:
+		ctx.insertComment("#" + x.Comment)
+	case *mkparser.Assignment:
+		ctx.handleAssignment(x)
+	case *mkparser.Variable:
+		ctx.handleVariable(x)
+	case *mkparser.Directive:
+		switch x.Name {
+		case "define":
+			ctx.handleDefine(x)
+		case "include", "-include":
+			ctx.handleInclude(node, ctx.parseMakeString(node, x.Args), x.Name[0] != '-')
+		default:
+			handled = false
+		}
+	default:
+		ctx.errorf(x, "unsupported line %s", x.Dump())
+	}
+	return handled
+}
+
+func (ctx *parseContext) insertComment(s string) {
+	ctx.receiver.newNode(&commentNode{strings.TrimSpace(s)})
+}
+
+func (ctx *parseContext) carryAsComment(failedNode mkparser.Node) {
+	for _, line := range strings.Split(failedNode.Dump(), "\n") {
+		ctx.insertComment("# " + line)
+	}
+}
+
+// records that the given node failed to be converted and includes an explanatory message
+func (ctx *parseContext) errorf(failedNode mkparser.Node, message string, args ...interface{}) {
+	if ctx.errorLogger != nil {
+		ctx.errorLogger.NewError(message, failedNode, args...)
+	}
+	message = fmt.Sprintf(message, args...)
+	ctx.insertComment(fmt.Sprintf("# MK2RBC TRANSLATION ERROR: %s", message))
+	ctx.carryAsComment(failedNode)
+	ctx.script.hasErrors = true
+}
+
+func (ctx *parseContext) wrapBadExpr(xBad *badExpr) {
+	ctx.insertComment(fmt.Sprintf("# MK2RBC TRANSLATION ERROR: %s", xBad.message))
+	ctx.carryAsComment(xBad.node)
+}
+
+func (ctx *parseContext) loadedModulePath(path string) string {
+	// During the transition to Roboleaf some of the product configuration files
+	// will be converted and checked in while the others will be generated on the fly
+	// and run. The runner  (rbcrun application) accommodates this by allowing three
+	// different ways to specify the loaded file location:
+	//  1) load(":<file>",...) loads <file> from the same directory
+	//  2) load("//path/relative/to/source/root:<file>", ...) loads <file> source tree
+	//  3) load("/absolute/path/to/<file> absolute path
+	// If the file being generated and the file it wants to load are in the same directory,
+	// generate option 1.
+	// Otherwise, if output directory is not specified, generate 2)
+	// Finally, if output directory has been specified and the file being generated and
+	// the file it wants to load from are in the different directories, generate 2) or 3):
+	//  * if the file being loaded exists in the source tree, generate 2)
+	//  * otherwise, generate 3)
+	// Finally, figure out the loaded module path and name and create a node for it
+	loadedModuleDir := filepath.Dir(path)
+	base := filepath.Base(path)
+	loadedModuleName := strings.TrimSuffix(base, filepath.Ext(base)) + ctx.outputSuffix
+	if loadedModuleDir == filepath.Dir(ctx.script.mkFile) {
+		return ":" + loadedModuleName
+	}
+	if ctx.outputDir == "" {
+		return fmt.Sprintf("//%s:%s", loadedModuleDir, loadedModuleName)
+	}
+	if _, err := os.Stat(filepath.Join(loadedModuleDir, loadedModuleName)); err == nil {
+		return fmt.Sprintf("//%s:%s", loadedModuleDir, loadedModuleName)
+	}
+	return filepath.Join(ctx.outputDir, loadedModuleDir, loadedModuleName)
+}
+
+func (ss *StarlarkScript) String() string {
+	return NewGenerateContext(ss).emit()
+}
+
+func (ss *StarlarkScript) SubConfigFiles() []string {
+	var subs []string
+	for _, src := range ss.inherited {
+		subs = append(subs, src.originalPath)
+	}
+	return subs
+}
+
+func (ss *StarlarkScript) HasErrors() bool {
+	return ss.hasErrors
+}
+
+// Convert reads and parses a makefile. If successful, parsed tree
+// is returned and then can be passed to String() to get the generated
+// Starlark file.
+func Convert(req Request) (*StarlarkScript, error) {
+	reader := req.Reader
+	if reader == nil {
+		mkContents, err := ioutil.ReadFile(req.MkFile)
+		if err != nil {
+			return nil, err
+		}
+		reader = bytes.NewBuffer(mkContents)
+	}
+	parser := mkparser.NewParser(req.MkFile, reader)
+	nodes, errs := parser.Parse()
+	if len(errs) > 0 {
+		for _, e := range errs {
+			fmt.Fprintln(os.Stderr, "ERROR:", e)
+		}
+		return nil, fmt.Errorf("bad makefile %s", req.MkFile)
+	}
+	starScript := &StarlarkScript{
+		moduleName:         moduleNameForFile(req.MkFile),
+		mkFile:             req.MkFile,
+		topDir:             req.RootDir,
+		traceCalls:         req.TraceCalls,
+		warnPartialSuccess: req.WarnPartialSuccess,
+	}
+	ctx := newParseContext(starScript, nodes)
+	ctx.outputSuffix = req.OutputSuffix
+	ctx.outputDir = req.OutputDir
+	ctx.errorLogger = req.ErrorLogger
+	if len(req.TracedVariables) > 0 {
+		ctx.tracedVariables = make(map[string]bool)
+		for _, v := range req.TracedVariables {
+			ctx.tracedVariables[v] = true
+		}
+	}
+	ctx.pushReceiver(starScript)
+	for ctx.hasNodes() && ctx.fatalError == nil {
+		node := ctx.getNode()
+		if ctx.handleSimpleStatement(node) {
+			continue
+		}
+		switch x := node.(type) {
+		case *mkparser.Directive:
+			switch x.Name {
+			case "ifeq", "ifneq", "ifdef", "ifndef":
+				ctx.handleIfBlock(x)
+			default:
+				ctx.errorf(x, "unexpected directive %s", x.Name)
+			}
+		default:
+			ctx.errorf(x, "unsupported line")
+		}
+	}
+	if ctx.fatalError != nil {
+		return nil, ctx.fatalError
+	}
+	return starScript, nil
+}
+
+func Launcher(path, name string) string {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "load(%q, %q)\n", baseUri, baseName)
+	fmt.Fprintf(&buf, "load(%q, \"init\")\n", path)
+	fmt.Fprintf(&buf, "g, config = %s(%q, init)\n", cfnMain, name)
+	fmt.Fprintf(&buf, "%s(g, config)\n", cfnPrintVars)
+	return buf.String()
+}
+
+func MakePath2ModuleName(mkPath string) string {
+	return strings.TrimSuffix(mkPath, filepath.Ext(mkPath))
+}