review: copy original bytecode.

Signed-off-by: Takeshi Yoneda <[email protected]>

Author: mathetake

src/common/bytecode_util.cc

@@ -219,6 +219,10 @@ bool BytecodeUtil::getStrippedSource(std::string_view bytecode, std::string &ret
       }
     }
   }
+  if (ret.empty()) {
+    // Copy the original source code if it is empty.
+    ret = std::string(bytecode);
+  }
   return true;
 }
 

src/common/bytecode_util.h

@@ -64,7 +64,7 @@ class BytecodeUtil {
   /**
    * getStrippedSource gets Wasm module without Custom Sections to save some memory in workers.
    * @param bytecode is the original bytecode.
-   * @param ret is the reference to the stripped bytecode.
+   * @param ret is the reference to the stripped bytecode or a copy of the original bytecode.
    * @return indicates whether parsing succeeded or not.
    */
   static bool getStrippedSource(std::string_view bytecode, std::string &ret);

src/v8/v8.cc

@@ -288,14 +288,7 @@ bool V8::load(const std::string &code, bool allow_precompiled) {
       fail(FailState::UnableToInitializeCode, "Failed to parse corrupted Wasm module");
       return false;
     };
-    wasm::vec<byte_t> code_vec = wasm::vec<byte_t>::invalid();
-    if (stripped.empty()) {
-      // Use the original bytecode.
-      code_vec = wasm::vec<byte_t>::make(code.size(), (char *)(code.data()));
-    } else {
-      // Othewise use the stripped bytecode.
-      code_vec = wasm::vec<byte_t>::make(stripped.size(), stripped.data());
-    }
+    wasm::vec<byte_t> code_vec = wasm::vec<byte_t>::make(stripped.size(), stripped.data());
     module_ = wasm::Module::make(store_.get(), code_vec);
   }
 

src/wasmtime/wasmtime.cc

@@ -128,13 +128,7 @@ bool Wasmtime::load(const std::string &code, bool allow_precompiled) {
   };
 
   WasmByteVec source_vec;
-  if (stripped_vec.empty()) {
-    // Use the original bytecode.
-    wasm_byte_vec_new(source_vec.get(), code.size(), code.data());
-  } else {
-    // Othewise pass the stripped source code.
-    wasm_byte_vec_new(source_vec.get(), stripped_vec.size(), stripped_vec.data());
-  }
+  wasm_byte_vec_new(source_vec.get(), stripped_vec.size(), stripped_vec.data());
   module_ = wasm_module_new(store_.get(), source_vec.get());
 
   if (module_) {

test/common/bytecode_util_test.cc

@@ -78,8 +78,11 @@ TEST(TestWasmCommonUtil, getStrippedSource) {
   auto source = readTestWasmFile("abi_export.wasm");
   std::string actual;
   EXPECT_TRUE(BytecodeUtil::getStrippedSource(source, actual));
-  // No `precompiled_` is found in the custom sections.
-  EXPECT_TRUE(actual.empty());
+  // If no `precompiled_` is found in the custom sections,
+  // then the copy of the original should be returned.
+  EXPECT_FALSE(actual.empty());
+  EXPECT_TRUE(actual.data() != source.data());
+  EXPECT_EQ(actual, source);
 
   // Append "precompiled_test" custom section
   std::vector<char> custom_section = {// custom section id