diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 4a18ead5e762..4d6d264ee0a2 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -426,7 +426,7 @@ static std::string createResponseFile(const opt::InputArgList &Args,
     case OPT_manifestuac:
       break;
     default:
-      OS << toString(Arg) << "\n";
+      OS << toString(*Arg) << "\n";
     }
   }
 
@@ -674,7 +674,7 @@ void LinkerDriver::invokeMSVC(opt::InputArgList &Args) {
       break;
     case OPT_opt:
       if (!StringRef(Arg->getValue()).startswith("lld"))
-        Rsp += toString(Arg) + " ";
+        Rsp += toString(*Arg) + " ";
       break;
     case OPT_INPUT: {
       if (Optional<StringRef> Path = doFindFile(Arg->getValue())) {
@@ -686,7 +686,7 @@ void LinkerDriver::invokeMSVC(opt::InputArgList &Args) {
       break;
     }
     default:
-      Rsp += toString(Arg) + "\n";
+      Rsp += toString(*Arg) + "\n";
     }
   }
 
diff --git a/lld/COFF/InputFiles.cpp b/lld/COFF/InputFiles.cpp
index aa444ec44cb0..df72aa50aef6 100644
--- a/lld/COFF/InputFiles.cpp
+++ b/lld/COFF/InputFiles.cpp
@@ -493,7 +493,7 @@ static StringRef getBasename(StringRef Path) {
 }
 
 // Returns a string in the format of "foo.obj" or "foo.obj(bar.lib)".
-std::string lld::toString(coff::InputFile *File) {
+std::string lld::toString(const coff::InputFile *File) {
   if (!File)
     return "<internal>";
   if (File->ParentName.empty())
diff --git a/lld/COFF/InputFiles.h b/lld/COFF/InputFiles.h
index 10b0502e80b8..645fa38badc3 100644
--- a/lld/COFF/InputFiles.h
+++ b/lld/COFF/InputFiles.h
@@ -58,7 +58,7 @@ public:
   virtual ~InputFile() {}
 
   // Returns the filename.
-  StringRef getName() { return MB.getBufferIdentifier(); }
+  StringRef getName() const { return MB.getBufferIdentifier(); }
 
   // Reads a file (the constructor doesn't do that).
   virtual void parse() = 0;
@@ -229,7 +229,7 @@ private:
 };
 } // namespace coff
 
-std::string toString(coff::InputFile *File);
+std::string toString(const coff::InputFile *File);
 } // namespace lld
 
 #endif
diff --git a/lld/Common/Reproduce.cpp b/lld/Common/Reproduce.cpp
index 1e3dabaea0c5..7be4ea6bb98b 100644
--- a/lld/Common/Reproduce.cpp
+++ b/lld/Common/Reproduce.cpp
@@ -55,12 +55,12 @@ std::string lld::rewritePath(StringRef S) {
   return S;
 }
 
-std::string lld::toString(opt::Arg *Arg) {
-  std::string K = Arg->getSpelling();
-  if (Arg->getNumValues() == 0)
+std::string lld::toString(const opt::Arg &Arg) {
+  std::string K = Arg.getSpelling();
+  if (Arg.getNumValues() == 0)
     return K;
-  std::string V = quote(Arg->getValue());
-  if (Arg->getOption().getRenderStyle() == opt::Option::RenderJoinedStyle)
+  std::string V = quote(Arg.getValue());
+  if (Arg.getOption().getRenderStyle() == opt::Option::RenderJoinedStyle)
     return K + V;
   return K + " " + V;
 }
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index a3ab42d93b44..ff1dd2251de2 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -493,7 +493,7 @@ static StripPolicy getStrip(opt::InputArgList &Args) {
   return StripPolicy::Debug;
 }
 
-static uint64_t parseSectionAddress(StringRef S, opt::Arg *Arg) {
+static uint64_t parseSectionAddress(StringRef S, const opt::Arg &Arg) {
   uint64_t VA = 0;
   if (S.startswith("0x"))
     S = S.drop_front(2);
@@ -508,15 +508,15 @@ static StringMap<uint64_t> getSectionStartMap(opt::InputArgList &Args) {
     StringRef Name;
     StringRef Addr;
     std::tie(Name, Addr) = StringRef(Arg->getValue()).split('=');
-    Ret[Name] = parseSectionAddress(Addr, Arg);
+    Ret[Name] = parseSectionAddress(Addr, *Arg);
   }
 
   if (auto *Arg = Args.getLastArg(OPT_Ttext))
-    Ret[".text"] = parseSectionAddress(Arg->getValue(), Arg);
+    Ret[".text"] = parseSectionAddress(Arg->getValue(), *Arg);
   if (auto *Arg = Args.getLastArg(OPT_Tdata))
-    Ret[".data"] = parseSectionAddress(Arg->getValue(), Arg);
+    Ret[".data"] = parseSectionAddress(Arg->getValue(), *Arg);
   if (auto *Arg = Args.getLastArg(OPT_Tbss))
-    Ret[".bss"] = parseSectionAddress(Arg->getValue(), Arg);
+    Ret[".bss"] = parseSectionAddress(Arg->getValue(), *Arg);
   return Ret;
 }
 
diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
index 56f9c0ffc3d2..9fa6f620abcb 100644
--- a/lld/ELF/DriverUtils.cpp
+++ b/lld/ELF/DriverUtils.cpp
@@ -166,7 +166,7 @@ std::string elf::createResponseFile(const opt::InputArgList &Args) {
          << "\n";
       break;
     default:
-      OS << toString(Arg) << "\n";
+      OS << toString(*Arg) << "\n";
     }
   }
   return Data.str();
diff --git a/lld/include/lld/Common/Reproduce.h b/lld/include/lld/Common/Reproduce.h
index 9cc430e51859..0f425de269c7 100644
--- a/lld/include/lld/Common/Reproduce.h
+++ b/lld/include/lld/Common/Reproduce.h
@@ -33,7 +33,7 @@ std::string quote(StringRef S);
 std::string rewritePath(StringRef S);
 
 // Returns the string form of the given argument.
-std::string toString(llvm::opt::Arg *Arg);
+std::string toString(const llvm::opt::Arg &Arg);
 }
 
 #endif
diff --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp
index 9cb4e08619c3..bb93620a9311 100644
--- a/lld/wasm/InputFiles.cpp
+++ b/lld/wasm/InputFiles.cpp
@@ -264,7 +264,7 @@ void ArchiveFile::addMember(const Archive::Symbol *Sym) {
 }
 
 // Returns a string in the format of "foo.o" or "foo.a(bar.o)".
-std::string lld::toString(wasm::InputFile *File) {
+std::string lld::toString(const wasm::InputFile *File) {
   if (!File)
     return "<internal>";
 
diff --git a/lld/wasm/InputFiles.h b/lld/wasm/InputFiles.h
index 3467fb6c8e88..65b606a150ba 100644
--- a/lld/wasm/InputFiles.h
+++ b/lld/wasm/InputFiles.h
@@ -143,7 +143,7 @@ llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
 
 } // namespace wasm
 
-std::string toString(wasm::InputFile *File);
+std::string toString(const wasm::InputFile *File);
 
 } // namespace lld
 
diff --git a/lld/wasm/Symbols.cpp b/lld/wasm/Symbols.cpp
index ba23e395dd19..94851dd8e807 100644
--- a/lld/wasm/Symbols.cpp
+++ b/lld/wasm/Symbols.cpp
@@ -76,11 +76,11 @@ bool Symbol::isWeak() const { return Sym && Sym->isWeak(); }
 
 bool Symbol::isHidden() const { return Sym && Sym->isHidden(); }
 
-std::string lld::toString(wasm::Symbol &Sym) {
+std::string lld::toString(const wasm::Symbol &Sym) {
   return wasm::displayName(Sym.getName());
 }
 
-std::string lld::toString(wasm::Symbol::Kind &Kind) {
+std::string lld::toString(wasm::Symbol::Kind Kind) {
   switch (Kind) {
   case wasm::Symbol::DefinedFunctionKind:
     return "DefinedFunction";
diff --git a/lld/wasm/Symbols.h b/lld/wasm/Symbols.h
index 8e0e6d503b00..0817e4df835e 100644
--- a/lld/wasm/Symbols.h
+++ b/lld/wasm/Symbols.h
@@ -111,8 +111,8 @@ protected:
 } // namespace wasm
 
 // Returns a symbol name for an error message.
-std::string toString(wasm::Symbol &Sym);
-std::string toString(wasm::Symbol::Kind &Kind);
+std::string toString(const wasm::Symbol &Sym);
+std::string toString(wasm::Symbol::Kind Kind);
 
 } // namespace lld