| // Copyright 2020 Google Inc. All rights reserved. |
| // |
| // 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. |
| |
| package main |
| |
| import ( |
| "android/soong/android" |
| "fmt" |
| "io/ioutil" |
| "os" |
| "path/filepath" |
| "reflect" |
| "strings" |
| |
| "github.com/google/blueprint" |
| "github.com/google/blueprint/bootstrap/bpdoc" |
| "github.com/google/blueprint/proptools" |
| ) |
| |
| const ( |
| // The default `load` preamble for every generated BUILD file. |
| soongModuleLoad = `package(default_visibility = ["//visibility:public"]) |
| load("//:soong_module.bzl", "soong_module") |
| |
| ` |
| |
| // A macro call in the BUILD file representing a Soong module, with space |
| // for expanding more attributes. |
| soongModuleTarget = `soong_module( |
| name = "%s", |
| module_name = "%s", |
| module_type = "%s", |
| module_variant = "%s", |
| module_deps = %s, |
| %s)` |
| |
| // A simple provider to mark and differentiate Soong module rule shims from |
| // regular Bazel rules. Every Soong module rule shim returns a |
| // SoongModuleInfo provider, and can only depend on rules returning |
| // SoongModuleInfo in the `module_deps` attribute. |
| providersBzl = `SoongModuleInfo = provider( |
| fields = { |
| "name": "Name of module", |
| "type": "Type of module", |
| "variant": "Variant of module", |
| }, |
| ) |
| ` |
| |
| // The soong_module rule implementation in a .bzl file. |
| soongModuleBzl = ` |
| %s |
| |
| load(":providers.bzl", "SoongModuleInfo") |
| |
| def _generic_soong_module_impl(ctx): |
| return [ |
| SoongModuleInfo( |
| name = ctx.attr.module_name, |
| type = ctx.attr.module_type, |
| variant = ctx.attr.module_variant, |
| ), |
| ] |
| |
| generic_soong_module = rule( |
| implementation = _generic_soong_module_impl, |
| attrs = { |
| "module_name": attr.string(mandatory = True), |
| "module_type": attr.string(mandatory = True), |
| "module_variant": attr.string(), |
| "module_deps": attr.label_list(providers = [SoongModuleInfo]), |
| }, |
| ) |
| |
| soong_module_rule_map = { |
| %s} |
| |
| _SUPPORTED_TYPES = ["bool", "int", "string"] |
| |
| def _is_supported_type(value): |
| if type(value) in _SUPPORTED_TYPES: |
| return True |
| elif type(value) == "list": |
| supported = True |
| for v in value: |
| supported = supported and type(v) in _SUPPORTED_TYPES |
| return supported |
| else: |
| return False |
| |
| # soong_module is a macro that supports arbitrary kwargs, and uses module_type to |
| # expand to the right underlying shim. |
| def soong_module(name, module_type, **kwargs): |
| soong_module_rule = soong_module_rule_map.get(module_type) |
| |
| if soong_module_rule == None: |
| # This module type does not have an existing rule to map to, so use the |
| # generic_soong_module rule instead. |
| generic_soong_module( |
| name = name, |
| module_type = module_type, |
| module_name = kwargs.pop("module_name", ""), |
| module_variant = kwargs.pop("module_variant", ""), |
| module_deps = kwargs.pop("module_deps", []), |
| ) |
| else: |
| supported_kwargs = dict() |
| for key, value in kwargs.items(): |
| if _is_supported_type(value): |
| supported_kwargs[key] = value |
| soong_module_rule( |
| name = name, |
| **supported_kwargs, |
| ) |
| ` |
| |
| // A rule shim for representing a Soong module type and its properties. |
| moduleRuleShim = ` |
| def _%[1]s_impl(ctx): |
| return [SoongModuleInfo()] |
| |
| %[1]s = rule( |
| implementation = _%[1]s_impl, |
| attrs = %[2]s |
| ) |
| ` |
| ) |
| |
| var ( |
| // An allowlist of prop types that are surfaced from module props to rule |
| // attributes. (nested) dictionaries are notably absent here, because while |
| // Soong supports multi value typed and nested dictionaries, Bazel's rule |
| // attr() API supports only single-level string_dicts. |
| allowedPropTypes = map[string]bool{ |
| "int": true, // e.g. 42 |
| "bool": true, // e.g. True |
| "string_list": true, // e.g. ["a", "b"] |
| "string": true, // e.g. "a" |
| } |
| |
| // TODO(b/166563303): Specific properties of some module types aren't |
| // recognized by the documentation generator. As a workaround, hardcode a |
| // mapping of the module type to prop name to prop type here, and ultimately |
| // fix the documentation generator to also parse these properties correctly. |
| additionalPropTypes = map[string]map[string]string{ |
| // sdk and module_exports props are created at runtime using reflection. |
| // bpdocs isn't wired up to read runtime generated structs. |
| "sdk": { |
| "java_header_libs": "string_list", |
| "java_sdk_libs": "string_list", |
| "java_system_modules": "string_list", |
| "native_header_libs": "string_list", |
| "native_libs": "string_list", |
| "native_objects": "string_list", |
| "native_shared_libs": "string_list", |
| "native_static_libs": "string_list", |
| }, |
| "module_exports": { |
| "java_libs": "string_list", |
| "java_tests": "string_list", |
| "native_binaries": "string_list", |
| "native_shared_libs": "string_list", |
| }, |
| } |
| |
| // Certain module property names are blocklisted/ignored here, for the reasons commented. |
| ignoredPropNames = map[string]bool{ |
| "name": true, // redundant, since this is explicitly generated for every target |
| "from": true, // reserved keyword |
| "in": true, // reserved keyword |
| "arch": true, // interface prop type is not supported yet. |
| "multilib": true, // interface prop type is not supported yet. |
| "target": true, // interface prop type is not supported yet. |
| "visibility": true, // Bazel has native visibility semantics. Handle later. |
| "features": true, // There is already a built-in attribute 'features' which cannot be overridden. |
| } |
| ) |
| |
| func targetNameWithVariant(c *blueprint.Context, logicModule blueprint.Module) string { |
| name := "" |
| if c.ModuleSubDir(logicModule) != "" { |
| // TODO(b/162720883): Figure out a way to drop the "--" variant suffixes. |
| name = c.ModuleName(logicModule) + "--" + c.ModuleSubDir(logicModule) |
| } else { |
| name = c.ModuleName(logicModule) |
| } |
| |
| return strings.Replace(name, "//", "", 1) |
| } |
| |
| func qualifiedTargetLabel(c *blueprint.Context, logicModule blueprint.Module) string { |
| return "//" + |
| packagePath(c, logicModule) + |
| ":" + |
| targetNameWithVariant(c, logicModule) |
| } |
| |
| func packagePath(c *blueprint.Context, logicModule blueprint.Module) string { |
| return filepath.Dir(c.BlueprintFile(logicModule)) |
| } |
| |
| func escapeString(s string) string { |
| s = strings.ReplaceAll(s, "\\", "\\\\") |
| return strings.ReplaceAll(s, "\"", "\\\"") |
| } |
| |
| func makeIndent(indent int) string { |
| if indent < 0 { |
| panic(fmt.Errorf("indent column cannot be less than 0, but got %d", indent)) |
| } |
| return strings.Repeat(" ", indent) |
| } |
| |
| // prettyPrint a property value into the equivalent Starlark representation |
| // recursively. |
| func prettyPrint(propertyValue reflect.Value, indent int) (string, error) { |
| if isZero(propertyValue) { |
| // A property value being set or unset actually matters -- Soong does set default |
| // values for unset properties, like system_shared_libs = ["libc", "libm", "libdl"] at |
| // https://cs.android.com/android/platform/superproject/+/master:build/soong/cc/linker.go;l=281-287;drc=f70926eef0b9b57faf04c17a1062ce50d209e480 |
| // |
| // In Bazel-parlance, we would use "attr.<type>(default = <default value>)" to set the default |
| // value of unset attributes. |
| return "", nil |
| } |
| |
| var ret string |
| switch propertyValue.Kind() { |
| case reflect.String: |
| ret = fmt.Sprintf("\"%v\"", escapeString(propertyValue.String())) |
| case reflect.Bool: |
| ret = strings.Title(fmt.Sprintf("%v", propertyValue.Interface())) |
| case reflect.Int, reflect.Uint, reflect.Int64: |
| ret = fmt.Sprintf("%v", propertyValue.Interface()) |
| case reflect.Ptr: |
| return prettyPrint(propertyValue.Elem(), indent) |
| case reflect.Slice: |
| ret = "[\n" |
| for i := 0; i < propertyValue.Len(); i++ { |
| indexedValue, err := prettyPrint(propertyValue.Index(i), indent+1) |
| if err != nil { |
| return "", err |
| } |
| |
| if indexedValue != "" { |
| ret += makeIndent(indent + 1) |
| ret += indexedValue |
| ret += ",\n" |
| } |
| } |
| ret += makeIndent(indent) |
| ret += "]" |
| case reflect.Struct: |
| ret = "{\n" |
| // Sort and print the struct props by the key. |
| structProps := extractStructProperties(propertyValue, indent) |
| for _, k := range android.SortedStringKeys(structProps) { |
| ret += makeIndent(indent + 1) |
| ret += fmt.Sprintf("%q: %s,\n", k, structProps[k]) |
| } |
| ret += makeIndent(indent) |
| ret += "}" |
| case reflect.Interface: |
| // TODO(b/164227191): implement pretty print for interfaces. |
| // Interfaces are used for for arch, multilib and target properties. |
| return "", nil |
| default: |
| return "", fmt.Errorf( |
| "unexpected kind for property struct field: %s", propertyValue.Kind()) |
| } |
| return ret, nil |
| } |
| |
| // Converts a reflected property struct value into a map of property names and property values, |
| // which each property value correctly pretty-printed and indented at the right nest level, |
| // since property structs can be nested. In Starlark, nested structs are represented as nested |
| // dicts: https://docs.bazel.build/skylark/lib/dict.html |
| func extractStructProperties(structValue reflect.Value, indent int) map[string]string { |
| if structValue.Kind() != reflect.Struct { |
| panic(fmt.Errorf("Expected a reflect.Struct type, but got %s", structValue.Kind())) |
| } |
| |
| ret := map[string]string{} |
| structType := structValue.Type() |
| for i := 0; i < structValue.NumField(); i++ { |
| field := structType.Field(i) |
| if field.PkgPath != "" { |
| // Skip unexported fields. Some properties are |
| // internal to Soong only, and these fields do not have PkgPath. |
| continue |
| } |
| if proptools.HasTag(field, "blueprint", "mutated") { |
| continue |
| } |
| |
| fieldValue := structValue.Field(i) |
| if isZero(fieldValue) { |
| // Ignore zero-valued fields |
| continue |
| } |
| |
| propertyName := proptools.PropertyNameForField(field.Name) |
| prettyPrintedValue, err := prettyPrint(fieldValue, indent+1) |
| if err != nil { |
| panic( |
| fmt.Errorf( |
| "Error while parsing property: %q. %s", |
| propertyName, |
| err)) |
| } |
| if prettyPrintedValue != "" { |
| ret[propertyName] = prettyPrintedValue |
| } |
| } |
| |
| return ret |
| } |
| |
| func isStructPtr(t reflect.Type) bool { |
| return t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct |
| } |
| |
| // Generically extract module properties and types into a map, keyed by the module property name. |
| func extractModuleProperties(aModule android.Module) map[string]string { |
| ret := map[string]string{} |
| |
| // Iterate over this android.Module's property structs. |
| for _, properties := range aModule.GetProperties() { |
| propertiesValue := reflect.ValueOf(properties) |
| // Check that propertiesValue is a pointer to the Properties struct, like |
| // *cc.BaseLinkerProperties or *java.CompilerProperties. |
| // |
| // propertiesValue can also be type-asserted to the structs to |
| // manipulate internal props, if needed. |
| if isStructPtr(propertiesValue.Type()) { |
| structValue := propertiesValue.Elem() |
| for k, v := range extractStructProperties(structValue, 0) { |
| ret[k] = v |
| } |
| } else { |
| panic(fmt.Errorf( |
| "properties must be a pointer to a struct, got %T", |
| propertiesValue.Interface())) |
| } |
| |
| } |
| |
| return ret |
| } |
| |
| // FIXME(b/168089390): In Bazel, rules ending with "_test" needs to be marked as |
| // testonly = True, forcing other rules that depend on _test rules to also be |
| // marked as testonly = True. This semantic constraint is not present in Soong. |
| // To work around, rename "*_test" rules to "*_test_". |
| func canonicalizeModuleType(moduleName string) string { |
| if strings.HasSuffix(moduleName, "_test") { |
| return moduleName + "_" |
| } |
| |
| return moduleName |
| } |
| |
| type RuleShim struct { |
| // The rule class shims contained in a bzl file. e.g. ["cc_object", "cc_library", ..] |
| rules []string |
| |
| // The generated string content of the bzl file. |
| content string |
| } |
| |
| // Create <module>.bzl containing Bazel rule shims for every module type available in Soong and |
| // user-specified Go plugins. |
| // |
| // This function reuses documentation generation APIs to ensure parity between modules-as-docs |
| // and modules-as-code, including the names and types of module properties. |
| func createRuleShims(packages []*bpdoc.Package) (map[string]RuleShim, error) { |
| var propToAttr func(prop bpdoc.Property, propName string) string |
| propToAttr = func(prop bpdoc.Property, propName string) string { |
| // dots are not allowed in Starlark attribute names. Substitute them with double underscores. |
| propName = strings.ReplaceAll(propName, ".", "__") |
| if !shouldGenerateAttribute(propName) { |
| return "" |
| } |
| |
| // Canonicalize and normalize module property types to Bazel attribute types |
| starlarkAttrType := prop.Type |
| if starlarkAttrType == "list of strings" { |
| starlarkAttrType = "string_list" |
| } else if starlarkAttrType == "int64" { |
| starlarkAttrType = "int" |
| } else if starlarkAttrType == "" { |
| var attr string |
| for _, nestedProp := range prop.Properties { |
| nestedAttr := propToAttr(nestedProp, propName+"__"+nestedProp.Name) |
| if nestedAttr != "" { |
| // TODO(b/167662930): Fix nested props resulting in too many attributes. |
| // Let's still generate these, but comment them out. |
| attr += "# " + nestedAttr |
| } |
| } |
| return attr |
| } |
| |
| if !allowedPropTypes[starlarkAttrType] { |
| return "" |
| } |
| |
| return fmt.Sprintf(" %q: attr.%s(),\n", propName, starlarkAttrType) |
| } |
| |
| ruleShims := map[string]RuleShim{} |
| for _, pkg := range packages { |
| content := "load(\":providers.bzl\", \"SoongModuleInfo\")\n" |
| |
| bzlFileName := strings.ReplaceAll(pkg.Path, "android/soong/", "") |
| bzlFileName = strings.ReplaceAll(bzlFileName, ".", "_") |
| bzlFileName = strings.ReplaceAll(bzlFileName, "/", "_") |
| |
| rules := []string{} |
| |
| for _, moduleTypeTemplate := range moduleTypeDocsToTemplates(pkg.ModuleTypes) { |
| attrs := `{ |
| "module_name": attr.string(mandatory = True), |
| "module_variant": attr.string(), |
| "module_deps": attr.label_list(providers = [SoongModuleInfo]), |
| ` |
| for _, prop := range moduleTypeTemplate.Properties { |
| attrs += propToAttr(prop, prop.Name) |
| } |
| |
| for propName, propType := range additionalPropTypes[moduleTypeTemplate.Name] { |
| attrs += fmt.Sprintf(" %q: attr.%s(),\n", propName, propType) |
| } |
| |
| attrs += " }," |
| |
| rule := canonicalizeModuleType(moduleTypeTemplate.Name) |
| content += fmt.Sprintf(moduleRuleShim, rule, attrs) |
| rules = append(rules, rule) |
| } |
| |
| ruleShims[bzlFileName] = RuleShim{content: content, rules: rules} |
| } |
| return ruleShims, nil |
| } |
| |
| func createBazelOverlay(ctx *android.Context, bazelOverlayDir string) error { |
| blueprintCtx := ctx.Context |
| blueprintCtx.VisitAllModules(func(module blueprint.Module) { |
| buildFile, err := buildFileForModule(blueprintCtx, module) |
| if err != nil { |
| panic(err) |
| } |
| |
| buildFile.Write([]byte(generateSoongModuleTarget(blueprintCtx, module) + "\n\n")) |
| buildFile.Close() |
| }) |
| |
| if err := writeReadOnlyFile(bazelOverlayDir, "WORKSPACE", ""); err != nil { |
| return err |
| } |
| |
| if err := writeReadOnlyFile(bazelOverlayDir, "BUILD", ""); err != nil { |
| return err |
| } |
| |
| if err := writeReadOnlyFile(bazelOverlayDir, "providers.bzl", providersBzl); err != nil { |
| return err |
| } |
| |
| packages, err := getPackages(ctx) |
| if err != nil { |
| return err |
| } |
| ruleShims, err := createRuleShims(packages) |
| if err != nil { |
| return err |
| } |
| |
| for bzlFileName, ruleShim := range ruleShims { |
| if err := writeReadOnlyFile(bazelOverlayDir, bzlFileName+".bzl", ruleShim.content); err != nil { |
| return err |
| } |
| } |
| |
| return writeReadOnlyFile(bazelOverlayDir, "soong_module.bzl", generateSoongModuleBzl(ruleShims)) |
| } |
| |
| // Generate the content of soong_module.bzl with the rule shim load statements |
| // and mapping of module_type to rule shim map for every module type in Soong. |
| func generateSoongModuleBzl(bzlLoads map[string]RuleShim) string { |
| var loadStmts string |
| var moduleRuleMap string |
| for bzlFileName, ruleShim := range bzlLoads { |
| loadStmt := "load(\"//:" |
| loadStmt += bzlFileName |
| loadStmt += ".bzl\"" |
| for _, rule := range ruleShim.rules { |
| loadStmt += fmt.Sprintf(", %q", rule) |
| moduleRuleMap += " \"" + rule + "\": " + rule + ",\n" |
| } |
| loadStmt += ")\n" |
| loadStmts += loadStmt |
| } |
| |
| return fmt.Sprintf(soongModuleBzl, loadStmts, moduleRuleMap) |
| } |
| |
| func shouldGenerateAttribute(prop string) bool { |
| return !ignoredPropNames[prop] |
| } |
| |
| // props is an unsorted map. This function ensures that |
| // the generated attributes are sorted to ensure determinism. |
| func propsToAttributes(props map[string]string) string { |
| var attributes string |
| for _, propName := range android.SortedStringKeys(props) { |
| if shouldGenerateAttribute(propName) { |
| attributes += fmt.Sprintf(" %s = %s,\n", propName, props[propName]) |
| } |
| } |
| return attributes |
| } |
| |
| // Convert a module and its deps and props into a Bazel macro/rule |
| // representation in the BUILD file. |
| func generateSoongModuleTarget( |
| blueprintCtx *blueprint.Context, |
| module blueprint.Module) string { |
| |
| var props map[string]string |
| if aModule, ok := module.(android.Module); ok { |
| props = extractModuleProperties(aModule) |
| } |
| attributes := propsToAttributes(props) |
| |
| // TODO(b/163018919): DirectDeps can have duplicate (module, variant) |
| // items, if the modules are added using different DependencyTag. Figure |
| // out the implications of that. |
| depLabels := map[string]bool{} |
| blueprintCtx.VisitDirectDeps(module, func(depModule blueprint.Module) { |
| depLabels[qualifiedTargetLabel(blueprintCtx, depModule)] = true |
| }) |
| |
| depLabelList := "[\n" |
| for depLabel, _ := range depLabels { |
| depLabelList += fmt.Sprintf(" %q,\n", depLabel) |
| } |
| depLabelList += " ]" |
| |
| return fmt.Sprintf( |
| soongModuleTarget, |
| targetNameWithVariant(blueprintCtx, module), |
| blueprintCtx.ModuleName(module), |
| canonicalizeModuleType(blueprintCtx.ModuleType(module)), |
| blueprintCtx.ModuleSubDir(module), |
| depLabelList, |
| attributes) |
| } |
| |
| func buildFileForModule(ctx *blueprint.Context, module blueprint.Module) (*os.File, error) { |
| // Create nested directories for the BUILD file |
| dirPath := filepath.Join(bazelOverlayDir, packagePath(ctx, module)) |
| if _, err := os.Stat(dirPath); os.IsNotExist(err) { |
| os.MkdirAll(dirPath, os.ModePerm) |
| } |
| // Open the file for appending, and create it if it doesn't exist |
| f, err := os.OpenFile( |
| filepath.Join(dirPath, "BUILD.bazel"), |
| os.O_APPEND|os.O_CREATE|os.O_WRONLY, |
| 0644) |
| if err != nil { |
| return nil, err |
| } |
| |
| // If the file is empty, add the load statement for the `soong_module` rule |
| fi, err := f.Stat() |
| if err != nil { |
| return nil, err |
| } |
| if fi.Size() == 0 { |
| f.Write([]byte(soongModuleLoad + "\n")) |
| } |
| |
| return f, nil |
| } |
| |
| // The overlay directory should be read-only, sufficient for bazel query. The files |
| // are not intended to be edited by end users. |
| func writeReadOnlyFile(dir string, baseName string, content string) error { |
| pathToFile := filepath.Join(bazelOverlayDir, baseName) |
| // 0444 is read-only |
| return ioutil.WriteFile(pathToFile, []byte(content), 0444) |
| } |
| |
| func isZero(value reflect.Value) bool { |
| switch value.Kind() { |
| case reflect.Func, reflect.Map, reflect.Slice: |
| return value.IsNil() |
| case reflect.Array: |
| valueIsZero := true |
| for i := 0; i < value.Len(); i++ { |
| valueIsZero = valueIsZero && isZero(value.Index(i)) |
| } |
| return valueIsZero |
| case reflect.Struct: |
| valueIsZero := true |
| for i := 0; i < value.NumField(); i++ { |
| if value.Field(i).CanSet() { |
| valueIsZero = valueIsZero && isZero(value.Field(i)) |
| } |
| } |
| return valueIsZero |
| case reflect.Ptr: |
| if !value.IsNil() { |
| return isZero(reflect.Indirect(value)) |
| } else { |
| return true |
| } |
| default: |
| zeroValue := reflect.Zero(value.Type()) |
| result := value.Interface() == zeroValue.Interface() |
| return result |
| } |
| } |