[cfe] Remove error/warning on duplicate library name in export/import

Closes #42700

Change-Id: I1fd047ea91de45be727690cf6053298cecf91410
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155326
Reviewed-by: Jens Johansen <[email protected]>

Author: johnniwinther

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -2307,95 +2307,6 @@ Message _withArgumentsDuplicatedImportInType(String name, Uri uri_, Uri uri2_) {
       arguments: {'name': name, 'uri': uri_, 'uri2': uri2_});
 }
 
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Template<Message Function(String name)> templateDuplicatedLibraryExport =
-    const Template<Message Function(String name)>(
-        messageTemplate:
-            r"""A library with name '#name' is exported more than once.""",
-        withArguments: _withArgumentsDuplicatedLibraryExport);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Message Function(String name)> codeDuplicatedLibraryExport =
-    const Code<Message Function(String name)>(
-        "DuplicatedLibraryExport", templateDuplicatedLibraryExport,
-        analyzerCodes: <String>["EXPORT_DUPLICATED_LIBRARY_NAMED"]);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-Message _withArgumentsDuplicatedLibraryExport(String name) {
-  if (name.isEmpty) throw 'No name provided';
-  name = demangleMixinApplicationName(name);
-  return new Message(codeDuplicatedLibraryExport,
-      message: """A library with name '${name}' is exported more than once.""",
-      arguments: {'name': name});
-}
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Template<Message Function(String name)>
-    templateDuplicatedLibraryExportContext =
-    const Template<Message Function(String name)>(
-        messageTemplate: r"""'#name' is also exported here.""",
-        withArguments: _withArgumentsDuplicatedLibraryExportContext);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Message Function(String name)> codeDuplicatedLibraryExportContext =
-    const Code<Message Function(String name)>("DuplicatedLibraryExportContext",
-        templateDuplicatedLibraryExportContext,
-        severity: Severity.context);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-Message _withArgumentsDuplicatedLibraryExportContext(String name) {
-  if (name.isEmpty) throw 'No name provided';
-  name = demangleMixinApplicationName(name);
-  return new Message(codeDuplicatedLibraryExportContext,
-      message: """'${name}' is also exported here.""",
-      arguments: {'name': name});
-}
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Template<Message Function(String name)> templateDuplicatedLibraryImport =
-    const Template<Message Function(String name)>(
-        messageTemplate:
-            r"""A library with name '#name' is imported more than once.""",
-        withArguments: _withArgumentsDuplicatedLibraryImport);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Message Function(String name)> codeDuplicatedLibraryImport =
-    const Code<Message Function(String name)>(
-        "DuplicatedLibraryImport", templateDuplicatedLibraryImport,
-        analyzerCodes: <String>["IMPORT_DUPLICATED_LIBRARY_NAMED"],
-        severity: Severity.warning);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-Message _withArgumentsDuplicatedLibraryImport(String name) {
-  if (name.isEmpty) throw 'No name provided';
-  name = demangleMixinApplicationName(name);
-  return new Message(codeDuplicatedLibraryImport,
-      message: """A library with name '${name}' is imported more than once.""",
-      arguments: {'name': name});
-}
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Template<Message Function(String name)>
-    templateDuplicatedLibraryImportContext =
-    const Template<Message Function(String name)>(
-        messageTemplate: r"""'#name' is also imported here.""",
-        withArguments: _withArgumentsDuplicatedLibraryImportContext);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-const Code<Message Function(String name)> codeDuplicatedLibraryImportContext =
-    const Code<Message Function(String name)>("DuplicatedLibraryImportContext",
-        templateDuplicatedLibraryImportContext,
-        severity: Severity.context);
-
-// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
-Message _withArgumentsDuplicatedLibraryImportContext(String name) {
-  if (name.isEmpty) throw 'No name provided';
-  name = demangleMixinApplicationName(name);
-  return new Message(codeDuplicatedLibraryImportContext,
-      message: """'${name}' is also imported here.""",
-      arguments: {'name': name});
-}
-
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Template<Message Function(Token token)> templateDuplicatedModifier =
     const Template<Message Function(Token token)>(

pkg/front_end/lib/src/fasta/source/source_loader.dart

@@ -81,11 +81,8 @@ import '../builder/type_declaration_builder.dart';
 
 import '../export.dart' show Export;
 
-import '../import.dart' show Import;
-
 import '../fasta_codes.dart'
     show
-        LocatedMessage,
         Message,
         SummaryTemplate,
         Template,
@@ -100,10 +97,6 @@ import '../fasta_codes.dart'
         templateAmbiguousSupertypes,
         templateCantReadFile,
         templateCyclicClassHierarchy,
-        templateDuplicatedLibraryExport,
-        templateDuplicatedLibraryExportContext,
-        templateDuplicatedLibraryImport,
-        templateDuplicatedLibraryImportContext,
         templateExtendingEnum,
         templateExtendingRestricted,
         templateIllegalMixin,
@@ -916,82 +909,7 @@ class SourceLoader extends Loader {
 
   List<SourceClassBuilder> checkSemantics(ClassBuilder objectClass) {
     checkObjectClassHierarchy(objectClass);
-    List<SourceClassBuilder> classes = handleHierarchyCycles(objectClass);
-
-    // Check imports and exports for duplicate names.
-    // This is rather silly, e.g. it makes importing 'foo' and exporting another
-    // 'foo' ok.
-    builders.forEach((Uri uri, LibraryBuilder library) {
-      if (library is SourceLibraryBuilder && library.loader == this) {
-        // Check exports.
-        if (library.exports.isNotEmpty) {
-          Map<String, List<Export>> nameToExports;
-          bool errorExports = false;
-          for (Export export in library.exports) {
-            String name = export.exported?.name ?? '';
-            if (name != '') {
-              nameToExports ??= new Map<String, List<Export>>();
-              List<Export> exports = nameToExports[name] ??= <Export>[];
-              exports.add(export);
-              if (exports[0].exported != export.exported) errorExports = true;
-            }
-          }
-          if (errorExports) {
-            for (String name in nameToExports.keys) {
-              List<Export> exports = nameToExports[name];
-              if (exports.length < 2) continue;
-              List<LocatedMessage> context = <LocatedMessage>[];
-              for (Export export in exports.skip(1)) {
-                context.add(templateDuplicatedLibraryExportContext
-                    .withArguments(name)
-                    .withLocation(uri, export.charOffset, noLength));
-              }
-              library.addProblem(
-                  templateDuplicatedLibraryExport.withArguments(name),
-                  exports[0].charOffset,
-                  noLength,
-                  uri,
-                  context: context);
-            }
-          }
-        }
-
-        // Check imports.
-        if (library.imports.isNotEmpty) {
-          Map<String, List<Import>> nameToImports;
-          bool errorImports;
-          for (Import import in library.imports) {
-            String name = import.imported?.name ?? '';
-            if (name != '') {
-              nameToImports ??= new Map<String, List<Import>>();
-              List<Import> imports = nameToImports[name] ??= <Import>[];
-              imports.add(import);
-              if (imports[0].imported != import.imported) errorImports = true;
-            }
-          }
-          if (errorImports != null) {
-            for (String name in nameToImports.keys) {
-              List<Import> imports = nameToImports[name];
-              if (imports.length < 2) continue;
-              List<LocatedMessage> context = <LocatedMessage>[];
-              for (Import import in imports.skip(1)) {
-                context.add(templateDuplicatedLibraryImportContext
-                    .withArguments(name)
-                    .withLocation(uri, import.charOffset, noLength));
-              }
-              library.addProblem(
-                  templateDuplicatedLibraryImport.withArguments(name),
-                  imports[0].charOffset,
-                  noLength,
-                  uri,
-                  context: context);
-            }
-          }
-        }
-      }
-    });
-    ticker.logMs("Checked imports and exports for duplicate names");
-    return classes;
+    return handleHierarchyCycles(objectClass);
   }
 
   void buildComponent() {

pkg/front_end/messages.yaml

@@ -1902,38 +1902,13 @@ DuplicatedExport:
     lib2.dart: "class A {}"
     main.dart: "export 'lib1.dart'; export 'lib2.dart';"
 
-DuplicatedLibraryExport:
-  template: "A library with name '#name' is exported more than once."
-  analyzerCode: EXPORT_DUPLICATED_LIBRARY_NAMED
-  script:
-    lib1.dart: "library foo;"
-    lib2.dart: "library foo;"
-    main.dart: "export 'lib1.dart'; export 'lib2.dart';"
-
-DuplicatedLibraryExportContext:
-  template: "'#name' is also exported here."
-  severity: CONTEXT
-
 DuplicatedExportInType:
   template: "'#name' is exported from both '#uri' and '#uri2'."
 
 DuplicatedImport:
   template: "'#name' is imported from both '#uri' and '#uri2'."
   severity: IGNORED
 
-DuplicatedLibraryImport:
-  template: "A library with name '#name' is imported more than once."
-  severity: WARNING
-  analyzerCode: IMPORT_DUPLICATED_LIBRARY_NAMED
-  script:
-    lib1.dart: "library foo;"
-    lib2.dart: "library foo;"
-    main.dart: "import 'lib1.dart'; import 'lib2.dart';"
-
-DuplicatedLibraryImportContext:
-  template: "'#name' is also imported here."
-  severity: CONTEXT
-
 DuplicatedImportInType:
   template: "'#name' is imported from both '#uri' and '#uri2'."
   analyzerCode: AMBIGUOUS_IMPORT

pkg/front_end/testcases/nnbd/duplicate_import.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2020, 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 'duplicate_import_lib1.dart';
+import 'duplicate_import_lib2.dart';
+
+export 'duplicate_import_lib1.dart';
+export 'duplicate_import_lib2.dart';
+
+main() {}

pkg/front_end/testcases/nnbd/duplicate_import.dart.outline.expect

@@ -0,0 +1,17 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "org-dartlang-testcase:///duplicate_import_lib1.dart";
+import "org-dartlang-testcase:///duplicate_import_lib2.dart";
+export "org-dartlang-testcase:///duplicate_import_lib1.dart";
+export "org-dartlang-testcase:///duplicate_import_lib2.dart";
+
+static method main() → dynamic
+  ;
+
+library foo /*isNonNullableByDefault*/;
+import self as self2;
+
+
+library foo /*isNonNullableByDefault*/;
+import self as self3;

pkg/front_end/testcases/nnbd/duplicate_import.dart.strong.expect

@@ -0,0 +1,16 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "org-dartlang-testcase:///duplicate_import_lib1.dart";
+import "org-dartlang-testcase:///duplicate_import_lib2.dart";
+export "org-dartlang-testcase:///duplicate_import_lib1.dart";
+export "org-dartlang-testcase:///duplicate_import_lib2.dart";
+
+static method main() → dynamic {}
+
+library foo /*isNonNullableByDefault*/;
+import self as self2;
+
+
+library foo /*isNonNullableByDefault*/;
+import self as self3;

pkg/front_end/testcases/nnbd/duplicate_import.dart.strong.transformed.expect

@@ -0,0 +1,16 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "org-dartlang-testcase:///duplicate_import_lib1.dart";
+import "org-dartlang-testcase:///duplicate_import_lib2.dart";
+export "org-dartlang-testcase:///duplicate_import_lib1.dart";
+export "org-dartlang-testcase:///duplicate_import_lib2.dart";
+
+static method main() → dynamic {}
+
+library foo /*isNonNullableByDefault*/;
+import self as self2;
+
+
+library foo /*isNonNullableByDefault*/;
+import self as self3;

pkg/front_end/testcases/nnbd/duplicate_import.dart.textual_outline.expect

@@ -0,0 +1,6 @@
+import 'duplicate_import_lib1.dart';
+import 'duplicate_import_lib2.dart';
+export 'duplicate_import_lib1.dart';
+export 'duplicate_import_lib2.dart';
+
+main() {}

pkg/front_end/testcases/nnbd/duplicate_import.dart.textual_outline_modelled.expect

@@ -0,0 +1,6 @@
+import 'duplicate_import_lib1.dart';
+import 'duplicate_import_lib2.dart';
+export 'duplicate_import_lib1.dart';
+export 'duplicate_import_lib2.dart';
+
+main() {}

pkg/front_end/testcases/nnbd/duplicate_import.dart.weak.expect

@@ -0,0 +1,16 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "org-dartlang-testcase:///duplicate_import_lib1.dart";
+import "org-dartlang-testcase:///duplicate_import_lib2.dart";
+export "org-dartlang-testcase:///duplicate_import_lib1.dart";
+export "org-dartlang-testcase:///duplicate_import_lib2.dart";
+
+static method main() → dynamic {}
+
+library foo /*isNonNullableByDefault*/;
+import self as self2;
+
+
+library foo /*isNonNullableByDefault*/;
+import self as self3;

pkg/front_end/testcases/nnbd/duplicate_import.dart.weak.transformed.expect

@@ -0,0 +1,16 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+import "org-dartlang-testcase:///duplicate_import_lib1.dart";
+import "org-dartlang-testcase:///duplicate_import_lib2.dart";
+export "org-dartlang-testcase:///duplicate_import_lib1.dart";
+export "org-dartlang-testcase:///duplicate_import_lib2.dart";
+
+static method main() → dynamic {}
+
+library foo /*isNonNullableByDefault*/;
+import self as self2;
+
+
+library foo /*isNonNullableByDefault*/;
+import self as self3;

pkg/front_end/testcases/nnbd/duplicate_import_lib1.dart

@@ -0,0 +1,5 @@
+// Copyright (c) 2020, 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 foo;

pkg/front_end/testcases/nnbd/duplicate_import_lib2.dart

@@ -0,0 +1,5 @@
+// Copyright (c) 2020, 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 foo;