[jnigen] logging (#48)

Author: mahesh-hegde

pkgs/jnigen/lib/src/bindings/dart_bindings.dart

@@ -2,10 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:io';
-
 import 'package:jnigen/src/elements/elements.dart';
 import 'package:jnigen/src/config/config.dart';
+import 'package:jnigen/src/logging/logging.dart';
 import 'package:jnigen/src/util/rename_conflict.dart';
 
 import 'symbol_resolver.dart';
@@ -41,7 +40,9 @@ class DartBindingsGenerator {
     if (!decl.isIncluded) {
       return '';
     }
-    return _class(decl);
+    final bindings = _class(decl);
+    log.finest('generated bindings for class ${decl.binaryName}');
+    return bindings;
   }
 
   String _class(ClassDecl decl) {
@@ -72,7 +73,7 @@ class DartBindingsGenerator {
         s.write(_field(decl, field));
         s.writeln();
       } on SkipException catch (e) {
-        stderr.writeln('skip field ${decl.binaryName}#${field.name}: '
+        log.info('skip field ${decl.binaryName}#${field.name}: '
             '${e.message}');
       }
     }
@@ -85,7 +86,7 @@ class DartBindingsGenerator {
         s.write(_method(decl, method));
         s.writeln();
       } on SkipException catch (e) {
-        stderr.writeln('skip field ${decl.binaryName}#${method.name}: '
+        log.info('skip field ${decl.binaryName}#${method.name}: '
             '${e.message}');
       }
     }

pkgs/jnigen/lib/src/bindings/preprocessor.dart

@@ -2,11 +2,11 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:io';
-
 import 'package:jnigen/src/elements/elements.dart';
 import 'package:jnigen/src/config/config.dart';
+import 'package:jnigen/src/logging/logging.dart';
 import 'package:jnigen/src/util/rename_conflict.dart';
+
 import 'common.dart';
 
 /// Preprocessor which fills information needed by both Dart and C generators.
@@ -22,7 +22,7 @@ class ApiPreprocessor {
     if (decl.isPreprocessed) return;
     if (!_isClassIncluded(decl, config)) {
       decl.isIncluded = false;
-      stdout.writeln('exclude class ${decl.binaryName}');
+      log.info('exclude class ${decl.binaryName}');
       decl.isPreprocessed = true;
       return;
     }
@@ -37,11 +37,12 @@ class ApiPreprocessor {
         decl.nameCounts.addAll(superclass.nameCounts);
       }
     }
-
+    log.finest('Superclass of ${decl.binaryName} resolved to '
+        '${superclass?.binaryName}');
     for (var field in decl.fields) {
       if (!_isFieldIncluded(decl, field, config)) {
         field.isIncluded = false;
-        stderr.writeln('exclude ${decl.binaryName}#${field.name}');
+        log.info('exclude ${decl.binaryName}#${field.name}');
         continue;
       }
       field.finalName = renameConflict(decl.nameCounts, field.name);
@@ -50,7 +51,7 @@ class ApiPreprocessor {
     for (var method in decl.methods) {
       if (!_isMethodIncluded(decl, method, config)) {
         method.isIncluded = false;
-        stderr.writeln('exclude method ${decl.binaryName}#${method.name}');
+        log.info('exclude method ${decl.binaryName}#${method.name}');
         continue;
       }
       var realName = method.name;
@@ -76,6 +77,7 @@ class ApiPreprocessor {
       }
     }
     decl.isPreprocessed = true;
+    log.finest('preprocessed ${decl.binaryName}');
   }
 
   static bool _isFieldIncluded(ClassDecl decl, Field field, Config config) =>

pkgs/jnigen/lib/src/bindings/symbol_resolver.dart

@@ -6,6 +6,9 @@
 // a locally meaningful name, when creating dart bindings
 
 import 'dart:math';
+
+import 'package:jnigen/src/logging/logging.dart';
+
 import 'package:jnigen/src/util/name_utils.dart';
 
 abstract class SymbolResolver {
@@ -29,8 +32,9 @@ class PackagePathResolver implements SymbolResolver {
 
   final Map<String, String> _importedNameToPackage = {};
   final Map<String, String> _packageToImportedName = {};
-  // return null if type's package cannot be resolved
-  // else return the fully qualified name of type
+
+  /// Returns the dart name of the [binaryName] in current translation context,
+  /// or `null` if the name cannot be resolved.
   @override
   String? resolve(String binaryName) {
     if (predefined.containsKey(binaryName)) {
@@ -57,6 +61,7 @@ class PackagePathResolver implements SymbolResolver {
     }
 
     final packageImport = getImport(package, binaryName);
+    log.finest('$package resolved to $packageImport for $binaryName');
     if (packageImport == null) {
       return null;
     }
@@ -67,6 +72,8 @@ class PackagePathResolver implements SymbolResolver {
           'qualified binaryName');
     }
 
+    // We always name imports with an underscore suffix, so that they can be
+    // never shadowed by a parameter or local variable.
     var importedName = '${pkgName}_';
     int suffix = 0;
     while (_importedNameToPackage.containsKey(importedName)) {

pkgs/jnigen/lib/src/config/config.dart

@@ -9,6 +9,8 @@ import 'package:jnigen/src/elements/elements.dart';
 import 'yaml_reader.dart';
 import 'filters.dart';
 
+import 'package:logging/logging.dart';
+
 /// Configuration for dependencies to be downloaded using maven.
 ///
 /// Dependency names should be listed in groupId:artifactId:version format.
@@ -142,6 +144,7 @@ class Config {
     this.androidSdkConfig,
     this.mavenDownloads,
     this.summarizerOptions,
+    this.logLevel = Level.INFO,
     this.dumpJsonTo,
   });
 
@@ -205,8 +208,15 @@ class Config {
   /// Additional options for the summarizer component
   SummarizerOptions? summarizerOptions;
 
+  /// Log verbosity. The possible values in decreasing order of verbosity
+  /// are verbose > debug > info > warning > error. Defaults to [LogLevel.info]
+  Level logLevel = Level.INFO;
+
+  /// File to which JSON summary is written before binding generation.
   String? dumpJsonTo;
 
+  static final _levels = Map.fromEntries(
+      Level.LEVELS.map((l) => MapEntry(l.name.toLowerCase(), l)));
   static Uri? _toDirUri(String? path) =>
       path != null ? Uri.directory(path) : null;
   static List<Uri>? _toUris(List<String>? paths) =>
@@ -231,7 +241,7 @@ class Config {
       for (var exclusion in exclusions) {
         final split = exclusion.split('#');
         if (split.length != 2) {
-          throw FormatException('Error parsing exclusion: "$exclusion"; '
+          throw FormatException('Error parsing exclusion: "$exclusion": '
               'expected to be in binaryName#member format.');
         }
         filters.add(MemberNameFilter<T>.exclude(
@@ -252,6 +262,15 @@ class Config {
       return root;
     }
 
+    Level logLevelFromString(String? levelName) {
+      if (levelName == null) return Level.INFO;
+      final level = _levels[levelName.toLowerCase()];
+      if (level == null) {
+        throw ConfigError('Not a valid logging level: $levelName');
+      }
+      return level;
+    }
+
     final config = Config(
       sourcePath: _toUris(prov.getStringList(_Props.sourcePath)),
       classPath: _toUris(prov.getStringList(_Props.classPath)),
@@ -295,6 +314,12 @@ class Config {
               androidExample: prov.getString(_Props.androidExample),
             )
           : null,
+      logLevel: logLevelFromString(
+        prov.getOneOf(
+          _Props.logLevel,
+          {'error', 'warning', 'info', 'debug', 'verbose'},
+        ),
+      ),
     );
     if (missingValues.isNotEmpty) {
       stderr.write('Following config values are required but not provided\n'
@@ -333,6 +358,7 @@ class _Props {
   static const dartRoot = 'dart_root';
   static const preamble = 'preamble';
   static const libraryName = 'library_name';
+  static const logLevel = 'log_level';
 
   static const mavenDownloads = 'maven_downloads';
   static const sourceDeps = '$mavenDownloads.source_deps';

pkgs/jnigen/lib/src/generate_bindings.dart

@@ -10,8 +10,11 @@ import 'summary/summary.dart';
 import 'config/config.dart';
 import 'tools/tools.dart';
 import 'writers/writers.dart';
+import 'logging/logging.dart';
 
 Future<void> generateJniBindings(Config config) async {
+  setLoggingLevel(config.logLevel);
+
   await buildSummarizerIfNotExists();
 
   final summarizer = SummarizerCommand(
@@ -72,19 +75,19 @@ Future<void> generateJniBindings(Config config) async {
   try {
     input = await summarizer.getInputStream();
   } on Exception catch (e) {
-    stderr.writeln('error obtaining API summary: $e');
+    log.fatal('Cannot obtain API summary: $e');
     return;
   }
   final stream = JsonDecoder().bind(Utf8Decoder().bind(input));
   dynamic json;
   try {
     json = await stream.single;
   } on Exception catch (e) {
-    stderr.writeln('error while parsing summary: $e');
+    log.fatal('Cannot parse summary: $e');
     return;
   }
   if (json == null) {
-    stderr.writeln('error: expected JSON element from summarizer.');
+    log.fatal('Expected JSON element from summarizer.');
     return;
   }
   final list = json as List;
@@ -93,6 +96,6 @@ Future<void> generateJniBindings(Config config) async {
     await outputWriter.writeBindings(list.map((c) => ClassDecl.fromJson(c)));
   } on Exception catch (e, trace) {
     stderr.writeln(trace);
-    stderr.writeln('error writing bindings: $e');
+    log.fatal('Error while writing bindings: $e');
   }
 }

pkgs/jnigen/lib/src/logging/logging.dart

@@ -0,0 +1,30 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+import 'package:logging/logging.dart';
+
+const _ansiRed = '\x1b[31m';
+const _ansiDefault = '\x1b[39;49m';
+
+Logger log = Logger('jnigen');
+
+void setLoggingLevel(Level level) {
+  Logger.root.level = level;
+  Logger.root.onRecord.listen((r) {
+    var message = '(${r.loggerName}) ${r.level.name}: ${r.message}';
+    if (level == Level.SHOUT || level == Level.SEVERE) {
+      message = '$_ansiRed$message$_ansiDefault';
+    }
+    stderr.writeln(message);
+  });
+}
+
+extension FatalErrors on Logger {
+  void fatal(Object? message, {int exitCode = 2}) {
+    message = '${_ansiRed}Fatal: $message$_ansiDefault';
+    stderr.writeln(message);
+    exit(exitCode);
+  }
+}

pkgs/jnigen/lib/src/summary/summary.dart

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:io';
+import 'package:jnigen/src/logging/logging.dart';
 import 'package:jnigen/src/util/command_output.dart';
 
 /// A command based summary source which calls the ApiSummarizer command.
@@ -79,7 +80,7 @@ class SummarizerCommand {
     args.addAll(extraArgs);
     args.addAll(classes);
 
-    stderr.writeln('[exec] $exec ${args.join(' ')}');
+    log.info('execute $exec ${args.join(' ')}');
     final proc = await Process.start(exec, args,
         workingDirectory: workingDirectory?.toFilePath() ?? '.');
     prefixedCommandOutputStream('[ApiSummarizer]', proc.stderr)

pkgs/jnigen/lib/src/tools/android_sdk_tools.dart

@@ -5,6 +5,8 @@
 import 'dart:io';
 import 'package:path/path.dart';
 
+import 'package:jnigen/src/logging/logging.dart';
+
 class AndroidSdkTools {
   /// get path for android API sources
   static Future<String?> _getVersionDir(
@@ -25,7 +27,9 @@ class AndroidSdkTools {
 
   static Future<String?> getAndroidSourcesPath(
       {String? sdkRoot, required List<int> versionOrder}) async {
-    return _getVersionDir('sources', sdkRoot, versionOrder);
+    final dir = _getVersionDir('sources', sdkRoot, versionOrder);
+    log.info('Found sources at $dir');
+    return dir;
   }
 
   static Future<String?> _getFile(String relative, String file, String? sdkRoot,
@@ -34,6 +38,7 @@ class AndroidSdkTools {
     if (platform == null) return null;
     final filePath = join(platform, file);
     if (await File(filePath).exists()) {
+      log.info('Found $filePath');
       return filePath;
     }
     return null;
@@ -68,28 +73,31 @@ task listDependencies(type: Copy) {
   /// If current project is not directly buildable by gradle, eg: a plugin,
   /// a relative path to other project can be specified using [androidProject].
   static List<String> getGradleClasspaths([String androidProject = '.']) {
-    stderr.writeln('trying to obtain gradle classpaths...');
+    log.info('trying to obtain gradle classpaths...');
     final android = join(androidProject, 'android');
     final buildGradle = join(android, 'build.gradle');
     final buildGradleOld = join(android, 'build.gradle.old');
     final origBuild = File(buildGradle);
     final script = origBuild.readAsStringSync();
     origBuild.renameSync(buildGradleOld);
     origBuild.createSync();
+    log.finer('Writing temporary gradle script with stub function...');
     origBuild.writeAsStringSync('$script\n$_gradleListDepsFunction\n');
+    log.finer('Running gradle wrapper...');
     final procRes = Process.runSync('./gradlew', ['-q', 'listDependencies'],
         workingDirectory: android);
+    log.finer('Restoring build scripts');
     origBuild.writeAsStringSync(script);
     File(buildGradleOld).deleteSync();
     if (procRes.exitCode != 0) {
+      final inAndroidProject =
+          (androidProject == '.') ? '' : ' in $androidProject';
       throw Exception('\n\ngradle exited with exit code ${procRes.exitCode}\n'
           'This can be related to a known issue with gradle. Please run '
-          '`flutter build apk` in $androidProject and try again\n');
-    }
-    final gradleClassPaths = (procRes.stdout as String).split('\n');
-    if (gradleClassPaths.last.isEmpty) {
-      gradleClassPaths.removeLast();
+          '`flutter build apk`$inAndroidProject and try again\n');
     }
-    return gradleClassPaths;
+    final classpaths = (procRes.stdout as String).trim().split('\n');
+    log.info('Found release build classpath with ${classpaths.length} entries');
+    return classpaths;
   }
 }