[wasm] Rework encoding of local declarations.

src/wasm/encoder.cc

 // 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.
 
 #include "src/signature.h"
 
 #include "src/handles.h"
 #include "src/v8.h"
 #include "src/zone-containers.h"
 
 #include "src/wasm/ast-decoder.h"
 #include "src/wasm/encoder.h"
+#include "src/wasm/wasm-macro-gen.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-opcodes.h"
 
 #include "src/v8memory.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
 /*TODO: add error cases for adding too many locals, too many functions and bad
@@ skipping 220 matching lines @@
                                          bool exported, bool external)
     : params_(zone),
       exported_(exported),
       external_(external),
       body_(zone),
       name_(zone) {}
 
 
 uint32_t WasmFunctionEncoder::HeaderSize() const {
   uint32_t size = 3;
-  if (HasLocals()) size += 8;
   if (!external_) size += 2;
   if (HasName()) size += 4;
   return size;
 }
 
 
 uint32_t WasmFunctionEncoder::BodySize(void) const {
-  return external_ ? 0 : static_cast<uint32_t>(body_.size());
+  // TODO(titzer): embed a LocalDeclEncoder in the WasmFunctionEncoder
+  LocalDeclEncoder local_decl;
+  local_decl.AddLocals(local_i32_count_, kAstI32);
+  local_decl.AddLocals(local_i64_count_, kAstI64);
+  local_decl.AddLocals(local_f32_count_, kAstF32);
+  local_decl.AddLocals(local_f64_count_, kAstF64);
+
+  return external_ ? 0
+                   : static_cast<uint32_t>(body_.size() + local_decl.Size());
 }
 
 
 uint32_t WasmFunctionEncoder::NameSize() const {
   return HasName() ? static_cast<uint32_t>(name_.size()) : 0;
 }
 
 
 void WasmFunctionEncoder::Serialize(byte* buffer, byte** header,
                                     byte** body) const {
   uint8_t decl_bits = (exported_ ? kDeclFunctionExport : 0) |
                       (external_ ? kDeclFunctionImport : 0) |
-                      (HasLocals() ? kDeclFunctionLocals : 0) |
                       (HasName() ? kDeclFunctionName : 0);
 
   EmitUint8(header, decl_bits);
   EmitUint16(header, signature_index_);
 
   if (HasName()) {
     uint32_t name_offset = static_cast<uint32_t>(*body - buffer);
     EmitUint32(header, name_offset);
     std::memcpy(*body, &name_[0], name_.size());
     (*body) += name_.size();
   }
 
-  if (HasLocals()) {
-    EmitUint16(header, local_i32_count_);
-    EmitUint16(header, local_i64_count_);
-    EmitUint16(header, local_f32_count_);
-    EmitUint16(header, local_f64_count_);
-  }
 
   if (!external_) {
-    EmitUint16(header, static_cast<uint16_t>(body_.size()));
+    // TODO(titzer): embed a LocalDeclEncoder in the WasmFunctionEncoder
+    LocalDeclEncoder local_decl;
+    local_decl.AddLocals(local_i32_count_, kAstI32);
+    local_decl.AddLocals(local_i64_count_, kAstI64);
+    local_decl.AddLocals(local_f32_count_, kAstF32);
+    local_decl.AddLocals(local_f64_count_, kAstF64);
+
+    EmitUint16(header, static_cast<uint16_t>(body_.size() + local_decl.Size()));
+    (*header) += local_decl.Emit(*header);
     if (body_.size() > 0) {
       std::memcpy(*header, &body_[0], body_.size());
       (*header) += body_.size();
     }
   }
 }
 
 
 WasmDataSegmentEncoder::WasmDataSegmentEncoder(Zone* zone, const byte* data,
                                                uint32_t size, uint32_t dest)
@@ skipping 296 matching lines @@
       next = next | 0x80;
     }
     output.push_back(next);
     shift += 7;
   } while ((next & 0x80) != 0);
   return output;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8