[CFE/bazel/DDC] Match 'tags' to reuse compiler state

This CL introduces 'tags' as a way to distinguish different setups and
be able to throw away previous state when it cannot be used.
These tags are - for now - basically filled up with the roots used for
the multi root filesystem, the idea being, that if they have changed we
cannot reuse the old state.

Change-Id: I19e069513ce3836f5bc6abf047e4359836fc7e09
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/114945
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>

pkg/dev_compiler/lib/src/kernel/command.dart

@@ -275,6 +275,11 @@ Future<CompilerResult> _compile(List<String> args,
     doneInputSummaries = List<Component>(summaryModules.length);
     compilerState = await fe.initializeIncrementalCompiler(
         oldCompilerState,
+        {
+          "trackWidgetCreation=$trackWidgetCreation",
+          "multiRootScheme=${fileSystem.markerScheme}",
+          "multiRootRoots=${fileSystem.roots}",
+        },
         doneInputSummaries,
         compileSdk,
         sourcePathToUri(getSdkPath()),

pkg/front_end/lib/src/api_unstable/bazel_worker.dart

@@ -48,7 +48,7 @@ export '../fasta/severity.dart' show Severity;
 
 export 'compiler_state.dart' show InitializedCompilerState;
 
-import 'util.dart' show equalMaps;
+import 'util.dart' show equalMaps, equalSets;
 
 /// Initializes the compiler for a modular build.
 ///
@@ -56,6 +56,7 @@ import 'util.dart' show equalMaps;
 /// as necessary based on [workerInputDigests].
 Future<InitializedCompilerState> initializeIncrementalCompiler(
     InitializedCompilerState oldState,
+    Set<String> tags,
     Uri sdkSummary,
     Uri packagesFile,
     Uri librariesSpecificationUri,
@@ -84,7 +85,8 @@ Future<InitializedCompilerState> initializeIncrementalCompiler(
   if (oldState == null ||
       oldState.incrementalCompiler == null ||
       oldState.incrementalCompiler.outlineOnly != outlineOnly ||
-      !equalMaps(oldState.options.experimentalFlags, experimentalFlags)) {
+      !equalMaps(oldState.options.experimentalFlags, experimentalFlags) ||
+      !equalSets(oldState.tags, tags)) {
     // No - or immediately not correct - previous state.
     startOver = true;
 
@@ -212,6 +214,7 @@ Future<InitializedCompilerState> initializeIncrementalCompiler(
   return new InitializedCompilerState(options, processedOpts,
       workerInputCache: workerInputCache,
       incrementalCompiler: incrementalCompiler,
+      tags: tags,
       libraryToInputDill: libraryToInputDill);
 }
 

pkg/front_end/lib/src/api_unstable/compiler_state.dart

@@ -16,11 +16,13 @@ class InitializedCompilerState {
   final ProcessedOptions processedOpts;
   final Map<Uri, WorkerInputComponent> workerInputCache;
   final IncrementalCompiler incrementalCompiler;
+  final Set<String> tags;
   final Map<Uri, Uri> libraryToInputDill;
 
   InitializedCompilerState(this.options, this.processedOpts,
       {this.workerInputCache,
       this.incrementalCompiler,
+      this.tags,
       this.libraryToInputDill});
 }
 

pkg/front_end/lib/src/api_unstable/ddc.dart

@@ -33,7 +33,7 @@ import '../kernel_generator_impl.dart' show generateKernel;
 import 'compiler_state.dart'
     show InitializedCompilerState, WorkerInputComponent, digestsEqual;
 
-import 'util.dart' show equalLists, equalMaps;
+import 'util.dart' show equalLists, equalMaps, equalSets;
 
 export '../api_prototype/compiler_options.dart'
     show CompilerOptions, parseExperimentalFlags, parseExperimentalArguments;
@@ -134,6 +134,7 @@ Future<InitializedCompilerState> initializeCompiler(
 
 Future<InitializedCompilerState> initializeIncrementalCompiler(
     InitializedCompilerState oldState,
+    Set<String> tags,
     List<Component> doneInputSummaries,
     bool compileSdk,
     Uri sdkRoot,
@@ -169,8 +170,9 @@ Future<InitializedCompilerState> initializeIncrementalCompiler(
       cachedSdkInput == null ||
       !digestsEqual(cachedSdkInput.digest, sdkDigest) ||
       !equalMaps(oldState.options.experimentalFlags, experiments) ||
-      !equalMaps(oldState.options.environmentDefines, environmentDefines)) {
+      !equalMaps(oldState.options.environmentDefines, environmentDefines) ||
-    // No previous state.
+      !equalSets(oldState.tags, tags)) {
+    // No - or immediately not correct - previous state.
     options = new CompilerOptions()
       ..compileSdk = compileSdk
       ..sdkRoot = sdkRoot
@@ -283,6 +285,7 @@ Future<InitializedCompilerState> initializeIncrementalCompiler(
   return new InitializedCompilerState(options, processedOpts,
       workerInputCache: workerInputCache,
       incrementalCompiler: incrementalCompiler,
+      tags: tags,
       libraryToInputDill: libraryToInputDill);
 }
 

pkg/front_end/lib/src/api_unstable/util.dart

@@ -12,6 +12,16 @@ bool equalLists<T>(List<T> a, List<T> b) {
   return true;
 }
 
+bool equalSets<K>(Set<K> a, Set<K> b) {
+  if (identical(a, b)) return true;
+  if (a == null || b == null) return false;
+  if (a.length != b.length) return false;
+  for (K entry in a) {
+    if (!b.contains(entry)) return false;
+  }
+  return true;
+}
+
 bool equalMaps<K, V>(Map<K, V> a, Map<K, V> b) {
   if (identical(a, b)) return true;
   if (a == null || b == null) return false;

utils/bazel/kernel_worker.dart

@@ -272,6 +272,12 @@ Future<ComputeKernelResult> computeKernel(List<String> args,
     // TODO(sigmund): add support for experiments with the incremental compiler.
     state = await fe.initializeIncrementalCompiler(
         previousState,
+        {
+          "target=$targetName",
+          "trackWidgetCreation=$trackWidgetCreation",
+          "multiRootScheme=${fileSystem.markerScheme}",
+          "multiRootRoots=${fileSystem.roots}",
+        },
         _toUri(parsedArgs['dart-sdk-summary']),
         _toUri(parsedArgs['packages-file']),
         _toUri(parsedArgs['libraries-file']),