Integrity checker for CPS and Tree IR.

pkg/compiler/lib/src/dart_backend/backend.dart

 // Copyright (c) 2012, 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.
 
 part of dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 113 matching lines @@
     // Enqueue the methods that the VM might invoke on user objects because
     // we don't trust the resolution to always get these included.
     world.registerInvocation(new Selector.call("toString", null, 0));
     world.registerInvokedGetter(new Selector.getter("hashCode", null));
     world.registerInvocation(new Selector.binaryOperator("=="));
     world.registerInvocation(new Selector.call("compareTo", null, 1));
   }
 
   void codegen(CodegenWorkItem work) { }
 
+  static bool checkTreeIntegrity(tree_ir.ExecutableDefinition node) {
+    new CheckTreeIntegrity().check(node);
+    return true; // So this can be used from assert().
+  }
+
+  static bool checkCpsIntegrity(cps_ir.ExecutableDefinition node) {
+    new CheckCpsIntegrity().check(node);
+    return true; // So this can be used from assert().
+  }
+
   /// Create an [ElementAst] from the CPS IR.
   static ElementAst createElementAst(
        ElementAstCreationContext context,
        Element element,
        cps_ir.ExecutableDefinition cpsDefinition) {
+    context.traceCompilation(element.name);
+    context.traceGraph('CPS builder', cpsDefinition);
+    assert(checkCpsIntegrity(cpsDefinition));
+
     // Transformations on the CPS IR.
-    context.traceCompilation(element.name);
+    void applyCpsPass(cps_opt.Pass pass) {
+      pass.rewrite(cpsDefinition);
+      context.traceGraph(pass.passName, cpsDefinition);
+      assert(checkCpsIntegrity(cpsDefinition));
+    }
 
     // TODO(karlklose): enable type propagation for dart2dart when constant
     // types are correctly marked as instantiated (Issue 21880).
-    new TypePropagator(context.dartTypes,
-                       context.constantSystem,
-                       new UnitTypeSystem(),
-                       context.internalError)
-        .rewrite(cpsDefinition);
-    context.traceGraph("Sparse constant propagation", cpsDefinition);
-    new RedundantPhiEliminator().rewrite(cpsDefinition);
-    context.traceGraph("Redundant phi elimination", cpsDefinition);
-    new ShrinkingReducer().rewrite(cpsDefinition);
-    context.traceGraph("Shrinking reductions", cpsDefinition);
+    applyCpsPass(new TypePropagator(context.dartTypes,
+                           context.constantSystem,
+                           new UnitTypeSystem(),
+                           context.internalError));
+    applyCpsPass(new RedundantPhiEliminator());
+    applyCpsPass(new ShrinkingReducer());
 
     // Do not rewrite the IR after variable allocation.  Allocation
     // makes decisions based on an approximation of IR variable live
     // ranges that can be invalidated by transforming the IR.
     new cps_ir.RegisterAllocator(context.internalError).visit(cpsDefinition);
 
     tree_builder.Builder builder =
         new tree_builder.Builder(context.internalError);
     tree_ir.ExecutableDefinition treeDefinition = builder.build(cpsDefinition);
     assert(treeDefinition != null);
     context.traceGraph('Tree builder', treeDefinition);
+    assert(checkTreeIntegrity(treeDefinition));
 
     // Transformations on the Tree IR.
-    new StatementRewriter().rewrite(treeDefinition);
-    context.traceGraph('Statement rewriter', treeDefinition);
-    new CopyPropagator().rewrite(treeDefinition);
-    context.traceGraph('Copy propagation', treeDefinition);
-    new LoopRewriter().rewrite(treeDefinition);
-    context.traceGraph('Loop rewriter', treeDefinition);
-    new LogicalRewriter().rewrite(treeDefinition);
-    context.traceGraph('Logical rewriter', treeDefinition);
+    void applyTreePass(tree_opt.Pass pass) {
+      pass.rewrite(treeDefinition);
+      context.traceGraph(pass.passName, treeDefinition);
+      assert(checkTreeIntegrity(treeDefinition));
+    }
+
+    applyTreePass(new StatementRewriter());
+    applyTreePass(new CopyPropagator());
+    applyTreePass(new LoopRewriter());
+    applyTreePass(new LogicalRewriter());
+
+    // Backend-specific transformations.
     new backend_ast_emitter.UnshadowParameters().unshadow(treeDefinition);
     context.traceGraph('Unshadow parameters', treeDefinition);
 
     TreeElementMapping treeElements = new TreeElementMapping(element);
     backend_ast.ExecutableDefinition backendAst =
         backend_ast_emitter.emit(treeDefinition);
     Node frontend_ast = backend2frontend.emit(treeElements, backendAst);
     return new ElementAst(frontend_ast, treeElements);
 
   }
@@ skipping 356 matching lines @@
   }
 
   void traceGraph(String title, var irObject) {
     compiler.tracer.traceGraph(title, irObject);
   }
 
   DartTypes get dartTypes => compiler.types;
 
   InternalErrorFunction get internalError => compiler.internalError;
 }