Add asm.js typer / validator.

Walk asm.js module ASTs, attach concrete type information
in preparation for generating a WASM module.

cctest test coverage (mjsunit coming in later CL).
Expressions, function tables, and foreign functions have coverage.
Statement coverage to be expanded in a later CL.

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=test-asm-validator
R=rossberg@chromium.org,titzer@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1322773002

Cr-Commit-Position: refs/heads/master@{#30520}

BUILD.gn

@@ -1213,6 +1213,8 @@ source_set("v8_base") {
     "src/types-inl.h",
     "src/types.cc",
     "src/types.h",
+    "src/typing-asm.cc",
+    "src/typing-asm.h",
     "src/typing-reset.cc",
     "src/typing-reset.h",
     "src/typing.cc",

src/typing-asm.h

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TYPING_ASM_H_
+#define V8_TYPING_ASM_H_
+
+#include "src/allocation.h"
+#include "src/ast.h"
+#include "src/effects.h"
+#include "src/type-info.h"
+#include "src/types.h"
+#include "src/zone.h"
+
+namespace v8 {
+namespace internal {
+
+class ZoneTypeCache;
+
+class AsmTyper : public AstVisitor {
+ public:
+  explicit AsmTyper(Isolate* isolate, Zone* zone, Script* script,
+                    FunctionLiteral* root);
+  bool Validate();
+  const char* error_message() { return error_message_; }
+
+  DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
+
+ private:
+  Script* script_;
+  FunctionLiteral* root_;
+  bool valid_;
+
+  // Information for bi-directional typing with a cap on nesting depth.
+  Type* expected_type_;
+  Type* computed_type_;
+  int intish_;  // How many ops we've gone without a x|0.
+
+  Type* return_type_;  // Return type of last function.
+  size_t array_size_;  // Array size of last ArrayLiteral.
+
+  typedef ZoneMap<std::string, Type*> ObjectTypeMap;
+  ObjectTypeMap stdlib_types_;
+  ObjectTypeMap stdlib_heap_types_;
+  ObjectTypeMap stdlib_math_types_;
+
+  // Map from Variable* to global/local variable Type*.
+  ZoneHashMap global_variable_type_;
+  ZoneHashMap local_variable_type_;
+
+  bool in_function_;  // In module function?
+  bool building_function_tables_;
+
+  ZoneTypeCache const& cache_;
+
+  static const int kErrorMessageLimit = 100;
+  char error_message_[kErrorMessageLimit];
+
+  static const int kMaxUncombinedAdditiveSteps = 1 << 20;
+  static const int kMaxUncombinedMultiplicativeSteps = 1;
+
+  void InitializeStdlib();
+
+  void VisitDeclarations(ZoneList<Declaration*>* d) override;
+  void VisitStatements(ZoneList<Statement*>* s) override;
+
+  void VisitExpressionAnnotation(Expression* e);
+  void VisitFunctionAnnotation(FunctionLiteral* f);
+  void VisitAsmModule(FunctionLiteral* f);
+
+  void VisitHeapAccess(Property* expr);
+
+  int ElementShiftSize(Type* type);
+
+  void SetType(Variable* variable, Type* type);
+  Type* GetType(Variable* variable);
+
+  Type* LibType(ObjectTypeMap map, Handle<String> name);
+
+  void SetResult(Expression* expr, Type* type);
+  void IntersectResult(Expression* expr, Type* type);
+
+  void VisitWithExpectation(Expression* expr, Type* expected_type,
+                            const char* msg);
+
+#define DECLARE_VISIT(type) virtual void Visit##type(type* node) override;
+  AST_NODE_LIST(DECLARE_VISIT)
+#undef DECLARE_VISIT
+
+  DISALLOW_COPY_AND_ASSIGN(AsmTyper);
+};
+}
+}  // namespace v8::internal
+
+#endif  // V8_TYPING_ASM_H_

test/cctest/cctest.gyp

@@ -101,6 +101,7 @@
         'test-array-list.cc',
         'test-ast.cc',
         'test-ast-expression-visitor.cc',
+        'test-asm-validator.cc',
         'test-atomicops.cc',
         'test-bignum.cc',
         'test-bignum-dtoa.cc',

tools/gyp/v8.gyp

@@ -973,6 +973,8 @@
         '../../src/types-inl.h',
         '../../src/types.cc',
         '../../src/types.h',
+        '../../src/typing-asm.cc',
+        '../../src/typing-asm.h',
         '../../src/typing-reset.cc',
         '../../src/typing-reset.h',
         '../../src/typing.cc',