Require unique_ptr to Module::addFunctionType() (#1672)

This fixes the memory leak in WasmBinaryBuilder::readSignatures() caused probably the exception thrown there before the FunctionType object is safe.

This also makes it clear that the Module becomes the owner of the FunctionType objects.

3 files changed, 9 insertions, 7 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index af42ed8a4..a78636c92 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -937,7 +937,7 @@ void WasmBinaryBuilder::readSignatures() {
   if (debug) std::cerr << "num: " << numTypes << std::endl;
   for (size_t i = 0; i < numTypes; i++) {
     if (debug) std::cerr << "read one" << std::endl;
-    auto curr = new FunctionType;
+    auto curr = make_unique<FunctionType>();
     auto form = getS32LEB();
     if (form != BinaryConsts::EncodedType::Func) {
       throwError("bad signature form " + std::to_string(form));
@@ -957,7 +957,7 @@ void WasmBinaryBuilder::readSignatures() {
       curr->result = getType();
     }
     curr->name = Name::fromInt(wasm.functionTypes.size());
-    wasm.addFunctionType(curr);
+    wasm.addFunctionType(std::move(curr));
   }
 }
 
diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index 0dfea962b..f5280bc33 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -421,7 +421,7 @@ void SExpressionWasmBuilder::preParseFunctionType(Element& s) {
       functionType->name = Name::fromInt(wasm.functionTypes.size());
       functionTypeNames.push_back(functionType->name);
       if (wasm.getFunctionTypeOrNull(functionType->name)) throw ParseException("duplicate function type", s.line, s.col);
-      wasm.addFunctionType(functionType.release());
+      wasm.addFunctionType(std::move(functionType));
     }
   }
 }
@@ -1828,7 +1828,7 @@ void SExpressionWasmBuilder::parseType(Element& s) {
   }
   functionTypeNames.push_back(type->name);
   if (wasm.getFunctionTypeOrNull(type->name)) throw ParseException("duplicate function type", s.line, s.col);
-  wasm.addFunctionType(type.release());
+  wasm.addFunctionType(std::move(type));
 }
 
 } // namespace wasm
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index cfee4f3c4..757bc1828 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -809,15 +809,17 @@ Global* Module::getGlobalOrNull(Name name) {
   return iter->second;
 }
 
-void Module::addFunctionType(FunctionType* curr) {
+FunctionType* Module::addFunctionType(std::unique_ptr<FunctionType> curr) {
   if (!curr->name.is()) {
     Fatal() << "Module::addFunctionType: empty name";
   }
   if (getFunctionTypeOrNull(curr->name)) {
     Fatal() << "Module::addFunctionType: " << curr->name << " already exists";
   }
-  functionTypes.push_back(std::unique_ptr<FunctionType>(curr));
-  functionTypesMap[curr->name] = curr;
+  auto* p = curr.get();
+  functionTypes.emplace_back(std::move(curr));
+  functionTypesMap[p->name] = p;
+  return p;
 }
 
 void Module::addExport(Export* curr) {