Introduce "platform configurations" to replace categories and libraries.dart.

pkg/compiler/lib/src/platform_configuration.dart

+// Copyright (c) 2015, the Fletch 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.md file.
+
+/// Tools for loading and parsing platform-configuration files.
+library plaform_configuration;
+
+import "dart:async";
+import "package:charcode/ascii.dart";
+import "../compiler_new.dart" as api;
+
+/// Parses an Ini-like format.
+///
+/// Sections are initialized with a name enclosed in brackets.
+/// Each section contain zero or more properties of the form "name:value".
+/// Empty lines are ignored.
+/// Lines starting with # are ignored.
+/// Duplicate names are not allowed.
+/// All keys and values will be passed through [String.trim].
+///
+/// If an error is found, a [FormatException] is thrown, using [sourceUri] in
+/// the error message.
+///
+/// Example
+/// ```
+/// [a]
+/// b:c
+///
+/// [d]
+/// e:file:///tmp/bla
+/// ```
+/// Will parse to {"a": {"b":"c"}, "d": {"e": "file:///tmp/bla"}}.
+
+Map<String, Map<String, String>> parseIni(List<int> source,
+    {Set<String> allowedSections, Uri sourceUri}) {
+  int startOfLine = 0;
+  int currentLine = 0;
+
+  error(String message, int index) {
+    int column = index - startOfLine + 1;
+    throw new FormatException(
+        "$sourceUri:$currentLine:$column: $message", sourceUri, index);
+  }
+
+  Map<String, Map<String, String>> result =
+      new Map<String, Map<String, String>>();
+  Map<String, String> currentSection = null;
+
+  if (source.length == 0) return result;
+  bool endOfFile = false;
+
+  // Iterate once per $lf in file.
+  while (!endOfFile) {
+    currentLine += 1;
+    int endOfLine = source.indexOf($lf, startOfLine);
+    if (endOfLine == -1) {
+      // The dart2js provider adds a final 0 to the file.
+      endOfLine = source.last == 0 ? source.length - 1 : source.length;
+      endOfFile = true;
+    }
+    if (startOfLine != endOfLine) {
+      int firstChar = source[startOfLine];
+      if (firstChar == $hash) {
+        // Comment, do nothing.
+      } else if (firstChar == $open_bracket) {
+        // Section header
+        int endOfHeader = source.indexOf($close_bracket, startOfLine);
+        if (endOfHeader == -1) {
+          error("'[' must be matched by ']' on the same line.", startOfLine);
+        }
+        if (endOfHeader == startOfLine + 1) {
+          error("Empty header name", startOfLine + 1);
+        }
+        if (endOfHeader != endOfLine - 1) {
+          error("Section heading lines must end with ']'", endOfHeader + 1);
+        }
+        int startOfSectionName = startOfLine + 1;
+        String sectionName = new String.fromCharCodes(
+            source, startOfSectionName, endOfHeader).trim();
+        currentSection = new Map<String, String>();
+        if (result.containsKey(sectionName)) {
+          error("Duplicate section name '$sectionName'", startOfSectionName);
+        }
+        if (allowedSections != null && !allowedSections.contains(sectionName)) {
+          error("Unrecognized section name '$sectionName'", startOfSectionName);
+        }
+        result[sectionName] = currentSection;
+      } else {
+        // Property line
+        if (currentSection == null) {
+          error("Property outside section", startOfLine);
+        }
+        int separator = source.indexOf($colon, startOfLine);
+        if (separator == startOfLine) {
+          error("Empty property name", startOfLine);
+        }
+        if (separator == -1 || separator > endOfLine) {
+          error("Property line without ':'", startOfLine);
+        }
+        String propertyName =
+            new String.fromCharCodes(source, startOfLine, separator).trim();
+        if (currentSection.containsKey(propertyName)) {
+          error("Duplicate property name '$propertyName'", startOfLine);
+        }
+        String propertyValue =
+            new String.fromCharCodes(source, separator + 1, endOfLine).trim();
+        currentSection[propertyName] = propertyValue;
+      }
+    }
+    startOfLine = endOfLine + 1;
+  }
+  return result;
+}
+
+const String librariesSection = "libraries";
+const String dartSpecSection = "dart-spec";
+const String featuresSection = "features";
+
+Map<String, Uri> libraryMappings(
+    Map<String, Map<String, String>> sections, Uri baseLocation) {
+  assert(sections.containsKey(librariesSection));
+  Map<String, Uri> result = new Map<String, Uri>();
+  sections[librariesSection].forEach((String name, String value) {
+    result[name] = baseLocation.resolve(value);
+  });
+  return result;
+}
+
+final Set<String> allowedSections =
+    new Set.from([librariesSection, dartSpecSection, featuresSection]);
+
+Future<Map<String, Uri>> load(Uri location, api.CompilerInput provider) {
+  return provider.readFromUri(location).then((contents) {
+    if (contents is String) {
+      contents = contents.codeUnits;
+    }
+    return libraryMappings(
+        parseIni(contents,
+            allowedSections: allowedSections, sourceUri: location),
+        location);
+  });
+}