From 3a56174d85a2c815ef55a24a6935fb4771201026 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas@devlieghere.com>
Date: Tue, 30 Jul 2019 19:34:26 +0000
Subject: [PATCH] [dsymutil] Pass LinkOptions by value instead of const ref.

When looping over the difference architectures in a fat binary, we
modify the link options before dispatching the link step to a different
thread. Passing the options by cont reference is not thread safe, as we
might modify its fields before the whole sturct is copied over.

Given that the link options are already stored in the DwarfLinker, we
can easily fix this by passing a copy of the link options instead of a
reference, which would just get copied later on.

llvm-svn: 367348
---
 llvm/tools/dsymutil/DwarfLinker.cpp | 4 ++--
 llvm/tools/dsymutil/DwarfLinker.h   | 6 +++---
 llvm/tools/dsymutil/dsymutil.h      | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/llvm/tools/dsymutil/DwarfLinker.cpp b/llvm/tools/dsymutil/DwarfLinker.cpp
index 0eeeca2..eb76b1a 100644
--- a/llvm/tools/dsymutil/DwarfLinker.cpp
+++ b/llvm/tools/dsymutil/DwarfLinker.cpp
@@ -2850,8 +2850,8 @@ bool DwarfLinker::link(const DebugMap &Map) {
 } // namespace dsymutil
 
 bool linkDwarf(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
-               const DebugMap &DM, const LinkOptions &Options) {
-  DwarfLinker Linker(OutFile, BinHolder, Options);
+               const DebugMap &DM, LinkOptions Options) {
+  DwarfLinker Linker(OutFile, BinHolder, std::move(Options));
   return Linker.link(DM);
 }
 
diff --git a/llvm/tools/dsymutil/DwarfLinker.h b/llvm/tools/dsymutil/DwarfLinker.h
index 482c607..f8b8729 100644
--- a/llvm/tools/dsymutil/DwarfLinker.h
+++ b/llvm/tools/dsymutil/DwarfLinker.h
@@ -56,8 +56,8 @@ using UnitListTy = std::vector<std::unique_ptr<CompileUnit>>;
 class DwarfLinker {
 public:
   DwarfLinker(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
-              const LinkOptions &Options)
-      : OutFile(OutFile), BinHolder(BinHolder), Options(Options) {}
+              LinkOptions Options)
+      : OutFile(OutFile), BinHolder(BinHolder), Options(std::move(Options)) {}
 
   /// Link the contents of the DebugMap.
   bool link(const DebugMap &);
@@ -499,7 +499,7 @@ private:
   /// be uniqued and sorted and there are only few entries expected
   /// per compile unit, which is why this is a std::map.
   std::map<std::string, std::string> ParseableSwiftInterfaces;
-  
+
   bool ModuleCacheHintDisplayed = false;
   bool ArchiveHintDisplayed = false;
 };
diff --git a/llvm/tools/dsymutil/dsymutil.h b/llvm/tools/dsymutil/dsymutil.h
index ac70bda..3c44b95 100644
--- a/llvm/tools/dsymutil/dsymutil.h
+++ b/llvm/tools/dsymutil/dsymutil.h
@@ -46,7 +46,7 @@ bool dumpStab(StringRef InputFile, ArrayRef<std::string> Archs,
 /// Link the Dwarf debug info as directed by the passed DebugMap \p DM into a
 /// DwarfFile named \p OutputFilename. \returns false if the link failed.
 bool linkDwarf(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
-               const DebugMap &DM, const LinkOptions &Options);
+               const DebugMap &DM, LinkOptions Options);
 
 } // end namespace dsymutil
 } // end namespace llvm
-- 
2.7.4