Use unique_ptr to handle ownership of synthesized args in DerivedArgList

This might be able to be simplified further by using Arg as a value type
in a linked list (to maintain pointer validity), but here's something
simple to start with.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206724 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 31 deletions

diff --git a/include/llvm/Option/ArgList.h b/include/llvm/Option/ArgList.h
index 6a51900d06..25248f444d 100644
--- a/include/llvm/Option/ArgList.h
+++ b/include/llvm/Option/ArgList.h
@@ -15,6 +15,7 @@
 #include "llvm/Option/OptSpecifier.h"
 #include "llvm/Option/Option.h"
 #include <list>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -334,7 +335,7 @@ class DerivedArgList : public ArgList {
   const InputArgList &BaseArgs;
 
   /// The list of arguments we synthesized.
-  mutable arglist_type SynthesizedArgs;
+  mutable SmallVector<std::unique_ptr<Arg>, 16> SynthesizedArgs;
 
 public:
   /// Construct a new derived arg list from \p BaseArgs.
@@ -358,9 +359,7 @@ public:
 
   /// AddSynthesizedArg - Add a argument to the list of synthesized arguments
   /// (to be freed).
-  void AddSynthesizedArg(Arg *A) {
-    SynthesizedArgs.push_back(A);
-  }
+  void AddSynthesizedArg(Arg *A);
 
   const char *MakeArgString(StringRef Str) const override;
 
diff --git a/lib/Option/ArgList.cpp b/lib/Option/ArgList.cpp
index 1b013f2c02..2d65c5ac87 100644
--- a/lib/Option/ArgList.cpp
+++ b/lib/Option/ArgList.cpp
@@ -9,6 +9,7 @@
 
 #include "llvm/Option/ArgList.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/Option.h"
@@ -348,52 +349,50 @@ DerivedArgList::DerivedArgList(const InputArgList &_BaseArgs)
   : BaseArgs(_BaseArgs) {
 }
 
-DerivedArgList::~DerivedArgList() {
-  // We only own the arguments we explicitly synthesized.
-  for (iterator it = SynthesizedArgs.begin(), ie = SynthesizedArgs.end();
-       it != ie; ++it)
-    delete *it;
-}
+DerivedArgList::~DerivedArgList() {}
 
 const char *DerivedArgList::MakeArgString(StringRef Str) const {
   return BaseArgs.MakeArgString(Str);
 }
 
+void DerivedArgList::AddSynthesizedArg(Arg *A) {
+  SynthesizedArgs.push_back(std::unique_ptr<Arg>(A));
+}
+
 Arg *DerivedArgList::MakeFlagArg(const Arg *BaseArg, const Option Opt) const {
-  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
-                                               Twine(Opt.getName())),
-                   BaseArgs.MakeIndex(Opt.getName()), BaseArg);
-  SynthesizedArgs.push_back(A);
-  return A;
+  SynthesizedArgs.push_back(make_unique<Arg>(
+      Opt,
+      ArgList::MakeArgString(Twine(Opt.getPrefix()) + Twine(Opt.getName())),
+      BaseArgs.MakeIndex(Opt.getName()), BaseArg));
+  return SynthesizedArgs.back().get();
 }
 
 Arg *DerivedArgList::MakePositionalArg(const Arg *BaseArg, const Option Opt,
                                        StringRef Value) const {
   unsigned Index = BaseArgs.MakeIndex(Value);
-  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
-                                               Twine(Opt.getName())),
-                   Index, BaseArgs.getArgString(Index), BaseArg);
-  SynthesizedArgs.push_back(A);
-  return A;
+  SynthesizedArgs.push_back(make_unique<Arg>(
+      Opt,
+      ArgList::MakeArgString(Twine(Opt.getPrefix()) + Twine(Opt.getName())),
+      Index, BaseArgs.getArgString(Index), BaseArg));
+  return SynthesizedArgs.back().get();
 }
 
 Arg *DerivedArgList::MakeSeparateArg(const Arg *BaseArg, const Option Opt,
                                      StringRef Value) const {
   unsigned Index = BaseArgs.MakeIndex(Opt.getName(), Value);
-  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
-                                               Twine(Opt.getName())),
-                   Index, BaseArgs.getArgString(Index + 1), BaseArg);
-  SynthesizedArgs.push_back(A);
-  return A;
+  SynthesizedArgs.push_back(make_unique<Arg>(
+      Opt,
+      ArgList::MakeArgString(Twine(Opt.getPrefix()) + Twine(Opt.getName())),
+      Index, BaseArgs.getArgString(Index + 1), BaseArg));
+  return SynthesizedArgs.back().get();
 }
 
 Arg *DerivedArgList::MakeJoinedArg(const Arg *BaseArg, const Option Opt,
                                    StringRef Value) const {
   unsigned Index = BaseArgs.MakeIndex(Opt.getName().str() + Value.str());
-  Arg *A = new Arg(Opt, ArgList::MakeArgString(Twine(Opt.getPrefix()) +
-                                               Twine(Opt.getName())), Index,
-                   BaseArgs.getArgString(Index) + Opt.getName().size(),
-                   BaseArg);
-  SynthesizedArgs.push_back(A);
-  return A;
+  SynthesizedArgs.push_back(make_unique<Arg>(
+      Opt,
+      ArgList::MakeArgString(Twine(Opt.getPrefix()) + Twine(Opt.getName())),
+      Index, BaseArgs.getArgString(Index) + Opt.getName().size(), BaseArg));
+  return SynthesizedArgs.back().get();
 }