[wasm] Refactor handling of data segments in WasmModuleBuilder.

src/wasm/wasm-module-builder.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/zone-containers.h"
 
@@ skipping 150 matching lines @@
   buffer.write_size(locals_size + body_.size());
   buffer.EnsureSpace(locals_size);
   byte** ptr = buffer.pos_ptr();
   locals_.Emit(*ptr);
   (*ptr) += locals_size;  // UGLY: manual bump of position pointer
   if (body_.size() > 0) {
     buffer.write(&body_[0], body_.size());
   }
 }
 
-WasmDataSegmentEncoder::WasmDataSegmentEncoder(Zone* zone, const byte* data,
-                                               uint32_t size, uint32_t dest)
-    : data_(zone), dest_(dest) {
-  for (size_t i = 0; i < size; ++i) {
-    data_.push_back(data[i]);
-  }
-}
-
-void WasmDataSegmentEncoder::Write(ZoneBuffer& buffer) const {
-  buffer.write_u8(0);  // linear memory zero
-  buffer.write_u8(kExprI32Const);
-  buffer.write_u32v(dest_);
-  buffer.write_u8(kExprEnd);
-  buffer.write_u32v(static_cast<uint32_t>(data_.size()));
-  buffer.write(&data_[0], data_.size());
-}
-
 WasmModuleBuilder::WasmModuleBuilder(Zone* zone)
     : zone_(zone),
       signatures_(zone),
       imports_(zone),
       functions_(zone),
       data_segments_(zone),
       indirect_functions_(zone),
       globals_(zone),
       signature_map_(zone),
       start_function_index_(-1) {}
 
 WasmFunctionBuilder* WasmModuleBuilder::AddFunction(FunctionSig* sig) {
   functions_.push_back(new (zone_) WasmFunctionBuilder(this));
   // Add the signature if one was provided here.
   if (sig) functions_.back()->SetSignature(sig);
   return functions_.back();
 }
 
-void WasmModuleBuilder::AddDataSegment(WasmDataSegmentEncoder* data) {
-  data_segments_.push_back(data);
+void WasmModuleBuilder::AddDataSegment(const byte* data, uint32_t size,
+                                       uint32_t dest) {
+  data_segments_.push_back({ZoneVector<byte>(zone()), dest});
+  ZoneVector<byte>& vec = data_segments_.back().data;
+  for (uint32_t i = 0; i < size; i++) {
+    vec.push_back(data[i]);
+  }
 }
 
 bool WasmModuleBuilder::CompareFunctionSigs::operator()(FunctionSig* a,
                                                         FunctionSig* b) const {
   if (a->return_count() < b->return_count()) return true;
   if (a->return_count() > b->return_count()) return false;
   if (a->parameter_count() < b->parameter_count()) return true;
   if (a->parameter_count() > b->parameter_count()) return false;
   for (size_t r = 0; r < a->return_count(); r++) {
     if (a->GetReturn(r) < b->GetReturn(r)) return true;
@@ skipping 28 matching lines @@
   imports_.push_back({AddSignature(sig), name, name_length});
   return static_cast<uint32_t>(imports_.size() - 1);
 }
 
 void WasmModuleBuilder::MarkStartFunction(WasmFunctionBuilder* function) {
   start_function_index_ = function->func_index();
 }
 
 uint32_t WasmModuleBuilder::AddGlobal(LocalType type, bool exported,
                                       bool mutability) {
-  globals_.push_back(std::make_tuple(type, exported, mutability));
+  globals_.push_back({type, exported, mutability});
   return static_cast<uint32_t>(globals_.size() - 1);
 }
 
 void WasmModuleBuilder::WriteTo(ZoneBuffer& buffer) const {
   uint32_t exports = 0;
 
   // == Emit magic =============================================================
   TRACE("emit magic\n");
   buffer.write_u32(kWasmMagic);
   buffer.write_u32(kWasmVersion);
@@ skipping 65 matching lines @@
     buffer.write_u32v(16);  // max memory size
     FixupSection(buffer, start);
   }
 
   // == Emit globals ===========================================================
   if (globals_.size() > 0) {
     size_t start = EmitSection(kGlobalSectionCode, buffer);
     buffer.write_size(globals_.size());
 
     for (auto global : globals_) {
-      static const int kLocalTypeIndex = 0;
-      static const int kMutabilityIndex = 2;
-      buffer.write_u8(
-          WasmOpcodes::LocalTypeCodeFor(std::get<kLocalTypeIndex>(global)));
-      buffer.write_u8(std::get<kMutabilityIndex>(global));
-      switch (std::get<kLocalTypeIndex>(global)) {
+      buffer.write_u8(WasmOpcodes::LocalTypeCodeFor(global.type));
+      buffer.write_u8(global.mutability ? 1 : 0);
+      switch (global.type) {
         case kAstI32: {
           static const byte code[] = {WASM_I32V_1(0)};
           buffer.write(code, sizeof(code));
           break;
         }
         case kAstF32: {
           static const byte code[] = {WASM_F32(0)};
           buffer.write(code, sizeof(code));
           break;
         }
@@ skipping 56 matching lines @@
     }
     FixupSection(buffer, start);
   }
 
   // == emit data segments =====================================================
   if (data_segments_.size() > 0) {
     size_t start = EmitSection(kDataSectionCode, buffer);
     buffer.write_size(data_segments_.size());
 
     for (auto segment : data_segments_) {
-      segment->Write(buffer);
+      buffer.write_u8(0);              // linear memory segment
+      buffer.write_u8(kExprI32Const);  // initializer expression for dest
+      buffer.write_u32v(segment.dest);
+      buffer.write_u8(kExprEnd);
+      buffer.write_u32v(static_cast<uint32_t>(segment.data.size()));
+      buffer.write(&segment.data[0], segment.data.size());
     }
     FixupSection(buffer, start);
   }
 
   // == Emit names =============================================================
   if (has_names) {
     // Emit the section code.
     buffer.write_u8(kUnknownSectionCode);
     // Emit a placeholder for the length.
     size_t start = buffer.reserve_u32v();
     // Emit the section string.
     buffer.write_size(4);
     buffer.write(reinterpret_cast<const byte*>("name"), 4);
     // Emit the names.
     buffer.write_size(functions_.size());
     for (auto function : functions_) {
       buffer.write_size(function->name_.size());
       if (function->name_.size() > 0) {
         buffer.write(reinterpret_cast<const byte*>(&function->name_[0]),
                      function->name_.size());
       }
       buffer.write_u8(0);
     }
     FixupSection(buffer, start);
   }
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8