Move most code from AstInferrerEngine to InferrerEngineImpl

pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart

Index: pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart
diff --git a/pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart b/pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart
index 66e380b04d09e249bff4e6b45562a6655dfd758d..0c0e24217f0b4ec0fdea8ff548c7fb7c54729a8e 100644
--- a/pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart
+++ b/pkg/compiler/lib/src/inferrer/ast_inferrer_engine.dart
@@ -11,18 +11,12 @@ import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../resolution/tree_elements.dart';
 import '../tree/nodes.dart' as ast;
-import '../types/constants.dart';
 import '../types/types.dart';
-import '../universe/selector.dart';
 import '../util/util.dart';
 import '../world.dart';
-import 'closure_tracer.dart';
-import 'debug.dart' as debug;
-import 'locals_handler.dart';
 import 'builder.dart';
 import 'builder_kernel.dart';
 import 'inferrer_engine.dart';
-import 'type_graph_dump.dart';
 import 'type_graph_nodes.dart';
 import 'type_system.dart';
 
@@ -35,11 +29,7 @@ class AstInferrerEngine extends InferrerEngineImpl<ast.Node> {
   GlobalTypeInferenceElementData<ast.Node> createElementData() =>
       new AstGlobalTypeInferenceElementData();
 
-  void runOverAllElements() {
-    if (compiler.disableTypeInference) return;
-    if (compiler.options.verbose) {
-      compiler.progress.reset();
-    }
+  void analyzeAllElements() {
     sortResolvedAsts().forEach((ResolvedAst resolvedAst) {
       if (compiler.shouldPrintProgress) {
         reporter.log('Added $addedInGraph elements in inferencing graph.');
@@ -55,336 +45,62 @@ class AstInferrerEngine extends InferrerEngineImpl<ast.Node> {
       types.withMember(member, () => analyze(member, body, null));
     });
     reporter.log('Added $addedInGraph elements in inferencing graph.');
+  }
 
-    TypeGraphDump dump = debug.PRINT_GRAPH ? new TypeGraphDump(this) : null;
-
-    dump?.beforeAnalysis();
-    buildWorkQueue();
-    refine();
-
-    // Try to infer element types of lists and compute their escape information.
-    types.allocatedLists.values.forEach((TypeInformation info) {
-      analyzeListAndEnqueue(info);
-    });
-
-    // Try to infer the key and value types for maps and compute the values'
-    // escape information.
-    types.allocatedMaps.values.forEach((TypeInformation info) {
-      analyzeMapAndEnqueue(info);
-    });
-
-    Set<FunctionEntity> bailedOutOn = new Set<FunctionEntity>();
-
-    // Trace closures to potentially infer argument types.
-    types.allocatedClosures.forEach((dynamic info) {
-      void trace(
-          Iterable<FunctionEntity> elements, ClosureTracerVisitor tracer) {
-        tracer.run();
-        if (!tracer.continueAnalyzing) {
-          elements.forEach((FunctionEntity _element) {
-            MethodElement element = _element;
-            MethodElement implementation = element.implementation;
-            closedWorldRefiner.registerMightBePassedToApply(element);
-            if (debug.VERBOSE) {
-              print("traced closure $element as ${true} (bail)");
-            }
-            implementation.functionSignature
-                .forEachParameter((FormalElement _parameter) {
-              ParameterElement parameter = _parameter;
-              types
-                  .getInferredTypeOfParameter(parameter)
-                  .giveUp(this, clearAssignments: false);
-            });
-          });
-          bailedOutOn.addAll(elements);
-          return;
-        }
-        elements
-            .where((e) => !bailedOutOn.contains(e))
-            .forEach((FunctionEntity _element) {
-          MethodElement element = _element;
-          MethodElement implementation = element.implementation;
-          implementation.functionSignature
-              .forEachParameter((FormalElement _parameter) {
-            ParameterElement parameter = _parameter;
-            ParameterTypeInformation info =
-                types.getInferredTypeOfParameter(parameter);
-            info.maybeResume();
-            workQueue.add(info);
-          });
-          if (tracer.tracedType.mightBePassedToFunctionApply) {
-            closedWorldRefiner.registerMightBePassedToApply(element);
-          }
-          if (debug.VERBOSE) {
-            print("traced closure $element as "
-                "${closedWorldRefiner
-                .getCurrentlyKnownMightBePassedToApply(element)}");
-          }
-        });
-      }
-
-      if (info is ClosureTypeInformation) {
-        Iterable<FunctionEntity> elements = [info.closure];
-        trace(elements, new ClosureTracerVisitor(elements, info, this));
-      } else if (info is CallSiteTypeInformation) {
-        if (info is StaticCallSiteTypeInformation &&
-            info.selector != null &&
-            info.selector.isCall) {
-          // This is a constructor call to a class with a call method. So we
-          // need to trace the call method here.
-          MethodElement calledElement = info.calledElement;
-          assert(calledElement.isGenerativeConstructor);
-          ClassElement cls = calledElement.enclosingClass;
-          MethodElement callMethod = cls.lookupMember(Identifiers.call);
-          if (callMethod == null) {
-            callMethod = cls.lookupMember(Identifiers.noSuchMethod_);
-          }
-          assert(callMethod != null, failedAt(cls));
-          Iterable<FunctionEntity> elements = [callMethod];
-          trace(elements, new ClosureTracerVisitor(elements, info, this));
-        } else {
-          // We only are interested in functions here, as other targets
-          // of this closure call are not a root to trace but an intermediate
-          // for some other function.
-          Iterable<FunctionEntity> elements = new List<FunctionEntity>.from(
-              info.callees.where((e) => e.isFunction));
-          trace(elements, new ClosureTracerVisitor(elements, info, this));
-        }
-      } else if (info is MemberTypeInformation) {
-        trace(<FunctionEntity>[info.member],
-            new StaticTearOffClosureTracerVisitor(info.member, info, this));
-      } else if (info is ParameterTypeInformation) {
-        failedAt(
-            NO_LOCATION_SPANNABLE, 'Unexpected closure allocation info $info');
-      }
+  void forEachParameter(
+      covariant MethodElement method, void f(Local parameter)) {
+    MethodElement implementation = method.implementation;
+    implementation.functionSignature
+        .forEachParameter((FormalElement _parameter) {
+      ParameterElement parameter = _parameter;
+      f(parameter);
     });
+  }
 
-    dump?.beforeTracing();
-
-    // Reset all nodes that use lists/maps that have been inferred, as well
-    // as nodes that use elements fetched from these lists/maps. The
-    // workset for a new run of the analysis will be these nodes.
-    Set<TypeInformation> seenTypes = new Set<TypeInformation>();
-    while (!workQueue.isEmpty) {
-      TypeInformation info = workQueue.remove();
-      if (seenTypes.contains(info)) continue;
-      // If the node cannot be reset, we do not need to update its users either.
-      if (!info.reset(this)) continue;
-      seenTypes.add(info);
-      workQueue.addAll(info.users);
-    }
-
-    workQueue.addAll(seenTypes);
-    refine();
-
-    if (debug.PRINT_SUMMARY) {
-      types.allocatedLists.values.forEach((_info) {
-        ListTypeInformation info = _info;
-        print('${info.type} '
-            'for ${info.originalType.allocationNode} '
-            'at ${info.originalType.allocationElement} '
-            'after ${info.refineCount}');
-      });
-      types.allocatedMaps.values.forEach((_info) {
-        MapTypeInformation info = _info;
-        print('${info.type} '
-            'for ${info.originalType.allocationNode} '
-            'at ${info.originalType.allocationElement} '
-            'after ${info.refineCount}');
-      });
-      types.allocatedClosures.forEach((TypeInformation info) {
-        if (info is ElementTypeInformation) {
-          print('${info.getInferredSignature(types)} for '
-              '${info.debugName}');
-        } else if (info is ClosureTypeInformation) {
-          print('${info.getInferredSignature(types)} for '
-              '${info.debugName}');
-        } else if (info is DynamicCallSiteTypeInformation) {
-          for (MemberEntity target in info.targets) {
-            if (target is FunctionEntity) {
-              print(
-                  '${types.getInferredSignatureOfMethod(target)} for ${target}');
-            } else {
-              print(
-                  '${types.getInferredTypeOfMember(target).type} for ${target}');
-            }
-          }
-        } else if (info is StaticCallSiteTypeInformation) {
-          ClassElement cls = info.calledElement.enclosingClass;
-          MethodElement callMethod = cls.lookupMember(Identifiers.call);
-          print('${types.getInferredSignatureOfMethod(callMethod)} for ${cls}');
-        } else {
-          print('${info.type} for some unknown kind of closure');
-        }
-      });
-      analyzedElements.forEach((MemberEntity elem) {
-        TypeInformation type = types.getInferredTypeOfMember(elem);
-        print('${elem} :: ${type} from ${type.assignments} ');
-      });
+  FunctionEntity lookupCallMethod(covariant ClassElement cls) {
+    MethodElement callMethod = cls.lookupMember(Identifiers.call);
+    if (callMethod == null) {
+      callMethod = cls.lookupMember(Identifiers.noSuchMethod_);
     }
-    dump?.afterAnalysis();
-
-    reporter.log('Inferred $overallRefineCount types.');
-
-    processLoopInformation();
+    return callMethod;
   }
 
-  void analyze(MemberEntity element, ast.Node body, ArgumentsTypes arguments) {
-    assert(!(element is MemberElement && !element.isDeclaration));
-    if (analyzedElements.contains(element)) return;
-    analyzedElements.add(element);
-
+  TypeInformation computeMemberTypeInformation(
+      MemberEntity member, ast.Node body) {
     dynamic visitor = compiler.options.kernelGlobalInference
-        ? new KernelTypeGraphBuilder(element, compiler, this)
-        : new ElementGraphBuilder(element, compiler, this);
-    TypeInformation type;
-    reporter.withCurrentElement(element, () {
-      // ignore: UNDEFINED_METHOD
-      type = visitor.run();
-    });
-    addedInGraph++;
+        ? new KernelTypeGraphBuilder(member, compiler, this)
+        : new ElementGraphBuilder(member, compiler, this);
+    // ignore: UNDEFINED_METHOD
+    return visitor.run();
+  }
 
-    if (element.isField) {
-      FieldElement field = element;
-      if (field.isFinal || field.isConst) {
-        // If [element] is final and has an initializer, we record
-        // the inferred type.
-        if (body != null) {
-          if (type is! ListTypeInformation && type is! MapTypeInformation) {
-            // For non-container types, the constant handler does
-            // constant folding that could give more precise results.
-            ConstantExpression constant = field.constant;
-            if (constant != null) {
-              ConstantValue value =
-                  compiler.backend.constants.getConstantValue(constant);
-              if (value != null) {
-                if (value.isFunction) {
-                  FunctionConstantValue functionConstant = value;
-                  MethodElement function = functionConstant.element;
-                  type = types.allocateClosure(function);
-                } else {
-                  // Although we might find a better type, we have to keep
-                  // the old type around to ensure that we get a complete view
-                  // of the type graph and do not drop any flow edges.
-                  TypeMask refinedType = computeTypeMask(closedWorld, value);
-                  assert(TypeMask.assertIsNormalized(refinedType, closedWorld));
-                  type = new NarrowTypeInformation(type, refinedType);
-                  types.allocatedTypes.add(type);
-                }
-              } else {
-                assert(
-                    field.isInstanceMember ||
-                        constant.isImplicit ||
-                        constant.isPotential,
-                    failedAt(
-                        field,
-                        "Constant expression without value: "
-                        "${constant.toStructuredText()}."));
-              }
-            }
-          }
-          recordTypeOfField(field, type);
-        } else if (!element.isInstanceMember) {
-          recordTypeOfField(field, types.nullType);
-        }
-      } else if (body == null) {
-        // Only update types of static fields if there is no
-        // assignment. Instance fields are dealt with in the constructor.
-        if (element.isStatic || element.isTopLevel) {
-          recordTypeOfField(field, type);
-        }
-      } else {
-        recordTypeOfField(field, type);
-      }
-      if ((element.isStatic || element.isTopLevel) &&
-          body != null &&
-          !element.isConst) {
-        dynamic argument = body;
-        // TODO(13429): We could do better here by using the
-        // constant handler to figure out if it's a lazy field or not.
-        if (argument.asSend() != null ||
-            (argument.asNewExpression() != null && !argument.isConst)) {
-          recordTypeOfField(field, types.nullType);
-        }
-      }
-    } else {
-      FunctionEntity method = element;
-      recordReturnType(method, type);
-    }
+  bool isFieldInitializerPotentiallyNull(
+      FieldEntity field, ast.Node initializer) {
+    dynamic argument = initializer;
+    // TODO(13429): We could do better here by using the
+    // constant handler to figure out if it's a lazy field or not.
+    return argument.asSend() != null ||
+        (argument.asNewExpression() != null && !argument.isConst);
   }
 
-  void updateParameterAssignments(TypeInformation caller, MemberEntity callee,
-      ArgumentsTypes arguments, Selector selector, TypeMask mask,
-      {bool remove, bool addToQueue: true}) {
-    if (callee.name == Identifiers.noSuchMethod_) return;
-    if (callee.isField) {
-      if (selector.isSetter) {
-        ElementTypeInformation info = types.getInferredTypeOfMember(callee);
-        if (remove) {
-          info.removeAssignment(arguments.positional[0]);
-        } else {
-          info.addAssignment(arguments.positional[0]);
-        }
-        if (addToQueue) workQueue.add(info);
-      }
-    } else if (callee.isGetter) {
-      return;
-    } else if (selector != null && selector.isGetter) {
-      // We are tearing a function off and thus create a closure.
-      assert(callee.isFunction);
-      MethodElement method = callee;
-      MemberTypeInformation info = types.getInferredTypeOfMember(method);
-      if (remove) {
-        info.closurizedCount--;
-      } else {
-        info.closurizedCount++;
-        if (Elements.isStaticOrTopLevel(method)) {
-          types.allocatedClosures.add(info);
-        } else {
-          // We add the call-site type information here so that we
-          // can benefit from further refinement of the selector.
-          types.allocatedClosures.add(caller);
-        }
-        FunctionElement function = method.implementation;
-        FunctionSignature signature = function.functionSignature;
-        signature.forEachParameter((FormalElement _parameter) {
-          ParameterElement parameter = _parameter;
-          ParameterTypeInformation info =
-              types.getInferredTypeOfParameter(parameter);
-          info.tagAsTearOffClosureParameter(this);
-          if (addToQueue) workQueue.add(info);
-        });
+  ConstantValue getFieldConstant(covariant FieldElement field) {
+    ConstantExpression constant = field.constant;
+    if (constant != null) {
+      ConstantValue value =
+          compiler.backend.constants.getConstantValue(constant);
+      if (value == null) {
+        assert(
+            field.isInstanceMember ||
+                constant.isImplicit ||
+                constant.isPotential,
+            failedAt(
+                field,
+                "Constant expression without value: "
+                "${constant.toStructuredText()}."));
       }
-    } else {
-      MethodElement method = callee;
-      FunctionElement function = method.implementation;
-      FunctionSignature signature = function.functionSignature;
-      int parameterIndex = 0;
-      bool visitingRequiredParameter = true;
-      signature.forEachParameter((FormalElement _parameter) {
-        ParameterElement parameter = _parameter;
-        if (signature.hasOptionalParameters &&
-            parameter == signature.optionalParameters.first) {
-          visitingRequiredParameter = false;
-        }
-        TypeInformation type = visitingRequiredParameter
-            ? arguments.positional[parameterIndex]
-            : signature.optionalParametersAreNamed
-                ? arguments.named[parameter.name]
-                : parameterIndex < arguments.positional.length
-                    ? arguments.positional[parameterIndex]
-                    : null;
-        if (type == null) type = getDefaultTypeOfParameter(parameter);
-        TypeInformation info = types.getInferredTypeOfParameter(parameter);
-        if (remove) {
-          info.removeAssignment(type);
-        } else {
-          info.addAssignment(type);
-        }
-        parameterIndex++;
-        if (addToQueue) workQueue.add(info);
-      });
+      return value;
     }
+    return null;
   }
 
   // Sorts the resolved elements by size. We do this for this inferrer