[WebAssembly] Pass ownership of body to SyntheticFunction. NFC

This avoids the Writer unnecessarily having a member to retain ownership
of the function body.

Differential Revision: https://reviews.llvm.org/D43933

llvm-svn: 326580

1 files changed, 10 insertions, 10 deletions

diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index dad2c5fa2df..1b7cde1e91b 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -17,7 +17,6 @@
 #include "WriterUtils.h"
 #include "lld/Common/ErrorHandler.h"
 #include "lld/Common/Memory.h"
-#include "lld/Common/Strings.h"
 #include "lld/Common/Threads.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/BinaryFormat/Wasm.h"
@@ -137,7 +136,6 @@ private:
   std::vector<OutputSection *> OutputSections;
 
   std::unique_ptr<FileOutputBuffer> Buffer;
-  std::string CtorFunctionBody;
 
   std::vector<OutputSegment *> Segments;
   llvm::SmallDenseMap<StringRef, OutputSegment *> SegmentMap;
@@ -859,10 +857,10 @@ void Writer::createCtorFunction() {
   uint32_t FunctionIndex = NumImportedFunctions + InputFunctions.size();
   WasmSym::CallCtors->setOutputIndex(FunctionIndex);
 
-  // First write the body bytes to a string.
-  std::string FunctionBody;
+  // First write the body's contents to a string.
+  std::string BodyContent;
   {
-    raw_string_ostream OS(FunctionBody);
+    raw_string_ostream OS(BodyContent);
     writeUleb128(OS, 0, "num locals");
     for (const WasmInitEntry &F : InitFunctions) {
       writeU8(OS, OPCODE_CALL, "CALL");
@@ -872,14 +870,16 @@ void Writer::createCtorFunction() {
   }
 
   // Once we know the size of the body we can create the final function body
-  raw_string_ostream OS(CtorFunctionBody);
-  writeUleb128(OS, FunctionBody.size(), "function size");
-  OS.flush();
-  CtorFunctionBody += FunctionBody;
+  std::string FunctionBody;
+  {
+    raw_string_ostream OS(FunctionBody);
+    writeUleb128(OS, BodyContent.size(), "function size");
+    OS << BodyContent;
+  }
 
   const WasmSignature *Sig = WasmSym::CallCtors->getFunctionType();
   SyntheticFunction *F = make<SyntheticFunction>(
-      *Sig, toArrayRef(CtorFunctionBody), WasmSym::CallCtors->getName());
+      *Sig, std::move(FunctionBody), WasmSym::CallCtors->getName());
 
   F->setOutputIndex(FunctionIndex);
   F->Live = true;