[llvm] Revert r231274: "Devirtualize ~parser<T> by making it protected in base classes and making derived classes final"

Summary: This patch was previously applied in r231221, and reverted in
r231254 because it broke self-hosting.  It was subsequently fixed and
reapplied in r231274.  Unfortunately, making the `parser<T>` classes
final prevents inheritance which makes it impossible to implement
custom parsers.

Reverting r231221 restores the ability to customize parsers.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: craig.topper, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60955

llvm-svn: 359902

1 files changed, 11 insertions, 16 deletions

diff --git a/llvm/include/llvm/Support/CommandLine.h b/llvm/include/llvm/Support/CommandLine.h
index 1fc26420fe6..7951128a48a 100644
--- a/llvm/include/llvm/Support/CommandLine.h
+++ b/llvm/include/llvm/Support/CommandLine.h
@@ -827,6 +827,8 @@ class basic_parser_impl { // non-template implementation of basic_parser<t>
 public:
   basic_parser_impl(Option &) {}
 
+  virtual ~basic_parser_impl() {}
+
   enum ValueExpected getValueExpectedFlagDefault() const {
     return ValueRequired;
   }
@@ -854,8 +856,6 @@ public:
   virtual void anchor();
 
 protected:
-  ~basic_parser_impl() = default;
-
   // A helper for basic_parser::printOptionDiff.
   void printOptionName(const Option &O, size_t GlobalWidth) const;
 };
@@ -869,15 +869,12 @@ public:
   using OptVal = OptionValue<DataType>;
 
   basic_parser(Option &O) : basic_parser_impl(O) {}
-
-protected:
-  ~basic_parser() = default;
 };
 
 //--------------------------------------------------
 // parser<bool>
 //
-template <> class parser<bool> final : public basic_parser<bool> {
+template <> class parser<bool> : public basic_parser<bool> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -904,8 +901,7 @@ extern template class basic_parser<bool>;
 
 //--------------------------------------------------
 // parser<boolOrDefault>
-template <>
-class parser<boolOrDefault> final : public basic_parser<boolOrDefault> {
+template <> class parser<boolOrDefault> : public basic_parser<boolOrDefault> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -931,7 +927,7 @@ extern template class basic_parser<boolOrDefault>;
 //--------------------------------------------------
 // parser<int>
 //
-template <> class parser<int> final : public basic_parser<int> {
+template <> class parser<int> : public basic_parser<int> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -953,7 +949,7 @@ extern template class basic_parser<int>;
 //--------------------------------------------------
 // parser<unsigned>
 //
-template <> class parser<unsigned> final : public basic_parser<unsigned> {
+template <> class parser<unsigned> : public basic_parser<unsigned> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -999,8 +995,7 @@ extern template class basic_parser<unsigned long>;
 // parser<unsigned long long>
 //
 template <>
-class parser<unsigned long long> final
-    : public basic_parser<unsigned long long> {
+class parser<unsigned long long> : public basic_parser<unsigned long long> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -1023,7 +1018,7 @@ extern template class basic_parser<unsigned long long>;
 //--------------------------------------------------
 // parser<double>
 //
-template <> class parser<double> final : public basic_parser<double> {
+template <> class parser<double> : public basic_parser<double> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -1045,7 +1040,7 @@ extern template class basic_parser<double>;
 //--------------------------------------------------
 // parser<float>
 //
-template <> class parser<float> final : public basic_parser<float> {
+template <> class parser<float> : public basic_parser<float> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -1067,7 +1062,7 @@ extern template class basic_parser<float>;
 //--------------------------------------------------
 // parser<std::string>
 //
-template <> class parser<std::string> final : public basic_parser<std::string> {
+template <> class parser<std::string> : public basic_parser<std::string> {
 public:
   parser(Option &O) : basic_parser(O) {}
 
@@ -1092,7 +1087,7 @@ extern template class basic_parser<std::string>;
 //--------------------------------------------------
 // parser<char>
 //
-template <> class parser<char> final : public basic_parser<char> {
+template <> class parser<char> : public basic_parser<char> {
 public:
   parser(Option &O) : basic_parser(O) {}