Initial import of v8-native WASM.

src/wasm/wasm-module.h

Index: src/wasm/wasm-module.h
diff --git a/src/wasm/wasm-module.h b/src/wasm/wasm-module.h
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+++ b/src/wasm/wasm-module.h
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+// 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_WASM_MODULE_H_
+#define V8_WASM_MODULE_H_
+
+#include "src/wasm/wasm-opcodes.h"
+#include "src/wasm/wasm-result.h"
+
+#include "src/api.h"
+#include "src/handles.h"
+
+namespace v8 {
+namespace internal {
+
+namespace compiler {
+class CallDescriptor;
+}
+
+namespace wasm {
+const size_t kMaxModuleSize = 1024 * 1024 * 1024;
+const size_t kMaxFunctionSize = 128 * 1024;
+const size_t kMaxStringSize = 256;
+
+enum WasmSectionDeclCode {
+  kDeclMemory = 0x00,
+  kDeclSignatures = 0x01,
+  kDeclFunctions = 0x02,
+  kDeclGlobals = 0x03,
+  kDeclDataSegments = 0x04,
+  kDeclFunctionTable = 0x05,
+  kDeclEnd = 0x06,
+};
+
+static const int kMaxModuleSectionCode = 6;
+
+enum WasmFunctionDeclBit {
+  kDeclFunctionName = 0x01,
+  kDeclFunctionImport = 0x02,
+  kDeclFunctionLocals = 0x04,
+  kDeclFunctionExport = 0x08
+};
+
+// Constants for fixed-size elements within a module.
+static const size_t kDeclMemorySize = 3;
+static const size_t kDeclGlobalSize = 6;
+static const size_t kDeclDataSegmentSize = 13;
+
+// Static representation of a wasm function.
+struct WasmFunction {
+  FunctionSig* sig;      // signature of the function.
+  uint16_t sig_index;    // index into the signature table.
+  uint32_t name_offset;  // offset in the module bytes of the name, if any.
+  uint32_t code_start_offset;    // offset in the module bytes of code start.
+  uint32_t code_end_offset;      // offset in the module bytes of code end.
+  uint16_t local_int32_count;    // number of int32 local variables.
+  uint16_t local_int64_count;    // number of int64 local variables.
+  uint16_t local_float32_count;  // number of float32 local variables.
+  uint16_t local_float64_count;  // number of float64 local variables.
+  bool exported;                 // true if this function is exported.
+  bool external;  // true if this function is externally supplied.
+};
+
+struct ModuleEnv;  // forward declaration of decoder interface.
+
+// Static representation of a wasm global variable.
+struct WasmGlobal {
+  uint32_t name_offset;  // offset in the module bytes of the name, if any.
+  MachineType type;      // type of the global.
+  uint32_t offset;       // offset from beginning of globals area.
+  bool exported;         // true if this global is exported.
+};
+
+// Static representation of a wasm data segment.
+struct WasmDataSegment {
+  uint32_t dest_addr;      // destination memory address of the data.
+  uint32_t source_offset;  // start offset in the module bytes.
+  uint32_t source_size;    // end offset in the module bytes.
+  bool init;               // true if loaded upon instantiation.
+};
+
+// Static representation of a module.
+struct WasmModule {
+  static const uint8_t kMinMemSize = 12;  // Minimum memory size = 4kb
+  static const uint8_t kMaxMemSize = 30;  // Maximum memory size = 1gb
+
+  Isolate* shared_isolate;    // isolate for storing shared code.
+  const byte* module_start;   // starting address for the module bytes.
+  const byte* module_end;     // end address for the module bytes.
+  uint8_t min_mem_size_log2;  // minimum size of the memory (log base 2).
+  uint8_t max_mem_size_log2;  // maximum size of the memory (log base 2).
+  bool mem_export;            // true if the memory is exported.
+  bool mem_external;          // true if the memory is external.
+
+  std::vector<WasmGlobal>* globals;             // globals in this module.
+  std::vector<FunctionSig*>* signatures;        // signatures in this module.
+  std::vector<WasmFunction>* functions;         // functions in this module.
+  std::vector<WasmDataSegment>* data_segments;  // data segments in this module.
+  std::vector<uint16_t>* function_table;        // function table.
+
+  // Get a pointer to a string stored in the module bytes representing a name.
+  const char* GetName(uint32_t offset) {
+    CHECK(BoundsCheck(offset, offset + 1));
+    if (offset == 0) return "<?>";  // no name.
+    return reinterpret_cast<const char*>(module_start + offset);
+  }
+
+  // Checks the given offset range is contained within the module bytes.
+  bool BoundsCheck(uint32_t start, uint32_t end) {
+    size_t size = module_end - module_start;
+    return start < size && end < size;
+  }
+
+  // Creates a new instantiation of the module in the given isolate.
+  MaybeHandle<JSObject> Instantiate(Isolate* isolate, Handle<JSObject> ffi,
+                                    Handle<JSArrayBuffer> memory);
+};
+
+// forward declaration.
+class WasmLinker;
+
+// Interface provided to the decoder/graph builder which contains only
+// minimal information about the globals, functions, and function tables.
+struct ModuleEnv {
+  uintptr_t globals_area;  // address of the globals area.
+  uintptr_t mem_start;     // address of the start of linear memory.
+  uintptr_t mem_end;       // address of the end of linear memory.
+
+  WasmModule* module;
+  WasmLinker* linker;
+  std::vector<Handle<Code>>* function_code;
+  Handle<FixedArray> function_table;
+  Handle<JSArrayBuffer> memory;
+  Handle<Context> context;
+  bool asm_js;  // true if the module originated from asm.js.
+
+  bool IsValidGlobal(uint32_t index) {
+    return module && index < module->globals->size();
+  }
+  bool IsValidFunction(uint32_t index) {
+    return module && index < module->functions->size();
+  }
+  bool IsValidSignature(uint32_t index) {
+    return module && index < module->signatures->size();
+  }
+  MachineType GetGlobalType(uint32_t index) {
+    DCHECK(IsValidGlobal(index));
+    return module->globals->at(index).type;
+  }
+  FunctionSig* GetFunctionSignature(uint32_t index) {
+    DCHECK(IsValidFunction(index));
+    return module->functions->at(index).sig;
+  }
+  FunctionSig* GetSignature(uint32_t index) {
+    DCHECK(IsValidSignature(index));
+    return module->signatures->at(index);
+  }
+  size_t FunctionTableSize() {
+    return module ? module->function_table->size() : 0;
+  }
+
+  Handle<Code> GetFunctionCode(uint32_t index);
+  Handle<FixedArray> GetFunctionTable();
+
+  compiler::CallDescriptor* GetWasmCallDescriptor(Zone* zone, FunctionSig* sig);
+  compiler::CallDescriptor* GetCallDescriptor(Zone* zone, uint32_t index);
+};
+
+std::ostream& operator<<(std::ostream& os, const WasmModule& module);
+std::ostream& operator<<(std::ostream& os, const WasmFunction& function);
+
+typedef Result<WasmModule*> ModuleResult;
+typedef Result<WasmFunction*> FunctionResult;
+
+// For testing. Decode, verify, and run the last exported function in the
+// given encoded module.
+int32_t CompileAndRunWasmModule(Isolate* isolate, const byte* module_start,
+                                const byte* module_end, bool asm_js = false);
+
+// For testing. Decode, verify, and run the last exported function in the
+// given decoded module.
+int32_t CompileAndRunWasmModule(Isolate* isolate, WasmModule* module);
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_MODULE_H_