Re-land "Search for main in the exported names of the main library, not in the library itself."

BUG=

Review URL: https://codereview.chromium.org//57433004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@29812 260f80e4-7a28-3924-810f-c04153c831b5

sdk/lib/_internal/compiler/implementation/compiler.dart

@@ -416,7 +416,9 @@ abstract class Compiler implements DiagnosticListener {
   LibraryElement jsHelperLibrary;
   LibraryElement interceptorsLibrary;
   LibraryElement foreignLibrary;
+
   LibraryElement mainApp;
+  FunctionElement mainFunction;
 
   /// Initialized when dart:mirrors is loaded.
   LibraryElement mirrorsLibrary;
@@ -1025,7 +1027,7 @@ abstract class Compiler implements DiagnosticListener {
   void compileLoadedLibraries() {
     Element main = null;
     if (mainApp != null) {
-      main = mainApp.find(MAIN);
+      main = mainApp.findExported(MAIN);
       if (main == null) {
         if (!analyzeOnly) {
           // Allow analyze only of libraries with no main.
@@ -1042,14 +1044,19 @@ abstract class Compiler implements DiagnosticListener {
               "Use '--analyze-all' to analyze all code in the library."});
         }
       } else {
-        if (!main.isFunction()) {
+        if (main.isErroneous()) {
+          reportFatalError(
+              main,
+              MessageKind.GENERIC,
+              {'text': "Error: Cannot determine which '$MAIN' to use."});
+        } else if (!main.isFunction()) {
           reportFatalError(
               main,
               MessageKind.GENERIC,
               {'text': "Error: '$MAIN' is not a function."});
         }
-        FunctionElement mainMethod = main;
-        FunctionSignature parameters = mainMethod.computeSignature(this);
+        mainFunction = main;
+        FunctionSignature parameters = mainFunction.computeSignature(this);
         if (parameters.parameterCount > 2) {
           int index = 0;
           parameters.forEachParameter((Element parameter) {
@@ -1110,7 +1117,7 @@ abstract class Compiler implements DiagnosticListener {
     if (hasIsolateSupport()) {
       enqueuer.codegen.addToWorkList(
           isolateHelperLibrary.find(Compiler.START_ROOT_ISOLATE));
-      enqueuer.codegen.registerGetOfStaticFunction(mainApp.find(MAIN));
+      enqueuer.codegen.registerGetOfStaticFunction(main);
     }
     if (enabledNoSuchMethod) {
       backend.enableNoSuchMethod(enqueuer.codegen);

sdk/lib/_internal/compiler/implementation/dart_backend/placeholder_collector.dart

@@ -163,7 +163,7 @@ class PlaceholderCollector extends Visitor {
   TreeElements treeElements;
 
   LibraryElement get coreLibrary => compiler.coreLibrary;
-  FunctionElement get entryFunction => compiler.mainApp.find(Compiler.MAIN);
+  FunctionElement get entryFunction => compiler.mainFunction;
   DartBackend get backend => compiler.backend;
 
   get currentFunctionScope => functionScopes.putIfAbsent(

sdk/lib/_internal/compiler/implementation/elements/elements.dart

@@ -694,6 +694,7 @@ abstract class LibraryElement extends Element implements ScopeContainerElement {
 
   Element find(String elementName);
   Element findLocal(String elementName);
+  Element findExported(String elementName);
   void forEachExport(f(Element element));
 
   bool hasLibraryName();

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

@@ -902,6 +902,14 @@ class LibraryElementX extends ElementX implements LibraryElement {
     return result;
   }
 
+  Element findExported(String elementName) {
+    for (Link link = exports; !link.isEmpty; link = link.tail) {
+      Element element = link.head;
+      if (element.name == elementName) return element;
+    }
+    return null;
+  }
+
   void forEachExport(f(Element element)) {
     exports.forEach((Element e) => f(e));
   }

sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.dart

@@ -959,7 +959,7 @@ class CodeEmitterTask extends CompilerTask {
 
   emitMain(CodeBuffer buffer) {
     if (compiler.isMockCompilation) return;
-    Element main = compiler.mainApp.find(Compiler.MAIN);
+    Element main = compiler.mainFunction;
     String mainCall = null;
     if (compiler.hasIsolateSupport()) {
       Element isolateMain =

tests/co19/co19-dart2dart.status

@@ -73,6 +73,8 @@ LibTest/typed_data/Float32x4/withZWInXY_A01_t01: Fail # co19 issue 650
 LibTest/typed_data/Float32x4/interleaveXY_A01_t01: Fail # co19 issue 650
 LibTest/typed_data/Float32x4/interleaveXYPairs_A01_t01: Fail # co19 issue 650
 
+Language/14_Libraries_and_Scripts/4_Scripts_A03_t02: Fail # co19 issue 654
+
 
 [ $compiler == dart2dart && $system == windows ]
 LibTest/core/double/operator_remainder_A01_t04: Fail # Result is NaN

tests/co19/co19-dart2js.status

@@ -238,6 +238,7 @@ LibTest/typed_data/ByteData/setUint8_A02_t02: fail # Issue 12989
 LibTest/typed_data/ByteData/setUint8_A02_t02: fail # Issue 12989
 
 Language/14_Libraries_and_Scripts/1_Imports_A04_t01: Fail # co19 Issue 603
+Language/14_Libraries_and_Scripts/4_Scripts_A03_t02: Fail # co19 issue 654
 
 [ $compiler == dart2js && $jscl ]
 LibTest/core/RegExp/Pattern_semantics/firstMatch_CharacterClassEscape_A03_t01: Fail, Pass # issue 3333

tests/compiler/dart2js/mock_compiler.dart

@@ -467,6 +467,7 @@ LibraryElement mockLibrary(Compiler compiler, String source) {
   Uri uri = new Uri(scheme: "source");
   var library = new LibraryElementX(new Script(uri, new MockFile(source)));
   importLibrary(library, compiler.coreLibrary, compiler);
+  library.setExports(<Element>[]);
   return library;
 }
 

tests/language/export_ambiguous_main_a.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2013, 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.
+
+library export_ambiguous_main_a;
+
+main() {
+  print('export_ambiguous_main_a');
+}

tests/language/export_ambiguous_main_b.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2013, 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.
+
+library export_ambiguous_main_b;
+
+main() {
+  print('export_ambiguous_main_b');
+}

tests/language/export_ambiguous_main_negative_test.dart

@@ -0,0 +1,6 @@
+// Copyright (c) 2013, 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.
+
+export 'export_ambiguous_main_a.dart';
+export 'export_ambiguous_main_b.dart';

tests/language/export_double_same_main_test.dart

@@ -0,0 +1,6 @@
+// Copyright (c) 2013, 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.
+
+export 'top_level_entry_test.dart';
+export 'export_main_test.dart' show main;

tests/language/export_main_override_test.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2013, 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.
+
+export 'top_level_entry_test.dart';
+
+main() {
+  print('export_main_override');
+}

tests/language/export_main_test.dart

@@ -0,0 +1,5 @@
+// Copyright (c) 2013, 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.
+
+export 'top_level_entry_test.dart';

tests/language/language.status

@@ -47,6 +47,8 @@ compile_time_constant_checked3_test/06: Fail, OK
 [ $runtime == vm || (($runtime == drt || $runtime == dartium) && $compiler == none) ]
 call_test: Fail # Issue 12602
 dynamic_prefix_core_test: Fail # Issue 12478
+export_main_test: Fail # Issue 14763
+export_double_same_main_test: Fail # Issue 14763
 
 [ $compiler == none && $runtime == drt ]
 mixin_illegal_object_test/01: pass # Issue 10952.

tests/language/language_analyzer.status

@@ -22,6 +22,8 @@ method_override7_test/03: Fail # Issue 11496
 
 built_in_identifier_test/none: Fail # Issue 13023
 
+export_double_same_main_test: Fail # Issue 14772
+
 # Please add new failing tests before this line.
 # Section below is for invalid tests.
 #
@@ -218,6 +220,7 @@ dynamic_field_test: StaticWarning
 dynamic_prefix_core_test: StaticWarning
 empty_block_case_test: StaticWarning
 error_stacktrace_test: StaticWarning
+export_ambiguous_main_negative_test: CompileTimeError
 extend_type_parameter2_negative_test: CompileTimeError
 extend_type_parameter_negative_test: CompileTimeError
 external_test/20: StaticWarning

tests/language/language_analyzer2.status

@@ -23,6 +23,8 @@ method_override8_test/03: Fail # Issue 11496
 
 built_in_identifier_test/none: Fail # Issue 13023
 
+export_double_same_main_test: Fail # Issue 14772
+
 # Please add new failing tests before this line.
 # Section below is for invalid tests.
 #
@@ -214,6 +216,7 @@ dynamic_field_test: StaticWarning
 dynamic_prefix_core_test: StaticWarning
 empty_block_case_test: StaticWarning
 error_stacktrace_test: StaticWarning
+export_ambiguous_main_negative_test: CompileTimeError
 extend_type_parameter2_negative_test: CompileTimeError
 extend_type_parameter_negative_test: CompileTimeError
 external_test/20: StaticWarning

tests/standalone/package/package1_test.dart

@@ -5,4 +5,8 @@
 // PackageRoot=none
 
 library package1_test;
-import 'package:package1.dart';
+import 'package:package1.dart' as p1;
+
+main() {
+  p1.main();
+}