[wasm] Lazy compilation for asm.js

src/wasm/wasm-objects.h

 // Copyright 2016 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_WASM_OBJECTS_H_
 #define V8_WASM_OBJECTS_H_
 
 #include "src/debug/debug.h"
 #include "src/debug/interface-types.h"
 #include "src/objects.h"
@@ skipping 146 matching lines @@
 };
 
 // Information shared by all WasmCompiledModule objects for the same module.
 class WasmSharedModuleData : public FixedArray {
   enum Fields {
     kModuleWrapper,
     kModuleBytes,
     kScript,
     kAsmJsOffsetTable,
     kBreakPointInfos,
+    kLazyCompilationOrchestrator,
     kFieldCount
   };
 
  public:
   DECLARE_CASTS(WasmSharedModuleData);
 
   DECLARE_GETTER(module, wasm::WasmModule);
   DECLARE_OPTIONAL_ACCESSORS(module_bytes, SeqOneByteString);
   DECLARE_GETTER(script, Script);
   DECLARE_OPTIONAL_ACCESSORS(asm_js_offset_table, ByteArray);
   DECLARE_OPTIONAL_GETTER(breakpoint_infos, FixedArray);
 
   static Handle<WasmSharedModuleData> New(
       Isolate* isolate, Handle<Foreign> module_wrapper,
       Handle<SeqOneByteString> module_bytes, Handle<Script> script,
       Handle<ByteArray> asm_js_offset_table);
 
   // Check whether this module was generated from asm.js source.
   bool is_asm_js();
 
   static void ReinitializeAfterDeserialization(Isolate*,
                                                Handle<WasmSharedModuleData>);
 
   static void AddBreakpoint(Handle<WasmSharedModuleData>, int position,
                             Handle<Object> break_point_object);
 
   static void SetBreakpointsOnNewInstance(Handle<WasmSharedModuleData>,
                                           Handle<WasmInstanceObject>);
+
+  static void PrepareForLazyCompilation(Handle<WasmSharedModuleData>);
+
+ private:
+  DECLARE_OPTIONAL_GETTER(lazy_compilation_orchestrator, Foreign);
+  friend class WasmCompiledModule;
 };
 
 class WasmCompiledModule : public FixedArray {
  public:
   enum Fields { kFieldCount };
 
   static WasmCompiledModule* cast(Object* fixed_array) {
     SLOW_DCHECK(IsWasmCompiledModule(fixed_array));
     return reinterpret_cast<WasmCompiledModule*>(fixed_array);
   }
@@ skipping 188 matching lines @@
   // location inside the same function.
   // If it points outside a function, or behind the last breakable location,
   // this function returns false and does not set any breakpoint.
   static bool SetBreakPoint(Handle<WasmCompiledModule>, int* position,
                             Handle<Object> break_point_object);
 
   // Return an empty handle if no breakpoint is hit at that location, or a
   // FixedArray with all hit breakpoint objects.
   MaybeHandle<FixedArray> CheckBreakPoints(int position);
 
+  // Compile lazily the function called in the given caller code object at the
+  // given offset.
+  // If the called function cannot be termined from the caller (indirect call /
+  // exported function), func_index must be set.
+  // If patch_caller is set, then at least the given all call site in the caller
+  // will be patched, potentially more call sites are updated.
+  // Returns the Code to be called at the given callsite, or an empty Handle if
+  // an error occured during lazy compilation. In this case, an exception has
+  // been set on the isolate.
+  static MaybeHandle<Code> CompileLazy(Isolate*, Handle<WasmInstanceObject>,
+                                       Handle<Code> caller, int offset,
+                                       int func_index, bool patch_caller);
+
  private:
   void InitId();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WasmCompiledModule);
 };
 
 class WasmDebugInfo : public FixedArray {
  public:
   enum Fields {
     kInstance,
@@ skipping 88 matching lines @@
   };
 };
 
 #undef DECLARE_ACCESSORS
 #undef DECLARE_OPTIONAL_ACCESSORS
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_OBJECTS_H_