r352925 - Factor out duplication between ExprIterator and ConstExprIterator.

[Richard Smith via cfe-commits]

Author: rsmith
Date: Fri Feb  1 13:58:17 2019
New Revision: 352925

URL: http://llvm.org/viewvc/llvm-project?rev=352925&view=rev
Log:
Factor out duplication between ExprIterator and ConstExprIterator.

This also exposes a more general iterator cast mechanism suitable for
use in http://reviews.llvm.org/D56571.

Modified:
    cfe/trunk/include/clang/AST/Stmt.h
    cfe/trunk/lib/CodeGen/CGCoroutine.cpp

Modified: cfe/trunk/include/clang/AST/Stmt.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Stmt.h?rev=352925&r1=352924&r2=352925&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Stmt.h (original)
+++ cfe/trunk/include/clang/AST/Stmt.h Fri Feb  1 13:58:17 2019
@@ -986,38 +986,31 @@ public:
   struct EmptyShell {};
 
 protected:
-  /// Iterator for iterating over Stmt * arrays that contain only Expr *
+  /// Iterator for iterating over Stmt * arrays that contain only T *.
   ///
   /// This is needed because AST nodes use Stmt* arrays to store
   /// references to children (to be compatible with StmtIterator).
-  struct ExprIterator
-      : llvm::iterator_adaptor_base<ExprIterator, Stmt **,
-                                    std::random_access_iterator_tag, Expr *> {
-    ExprIterator() : iterator_adaptor_base(nullptr) {}
-    ExprIterator(Stmt **I) : iterator_adaptor_base(I) {}
-
-    reference operator*() const {
-      assert((*I)->getStmtClass() >= firstExprConstant &&
-             (*I)->getStmtClass() <= lastExprConstant);
-      return *reinterpret_cast<Expr **>(I);
-    }
-  };
+  template<typename T, typename TPtr = T *, typename StmtPtr = Stmt *>
+  struct CastIterator
+      : llvm::iterator_adaptor_base<CastIterator<T, TPtr, StmtPtr>, StmtPtr *,
+                                    std::random_access_iterator_tag, TPtr> {
+    using Base = typename CastIterator::iterator_adaptor_base;
+
+    CastIterator() : Base(nullptr) {}
+    CastIterator(StmtPtr *I) : Base(I) {}
 
-  /// Const iterator for iterating over Stmt * arrays that contain only Expr *
-  struct ConstExprIterator
-      : llvm::iterator_adaptor_base<ConstExprIterator, const Stmt *const *,
-                                    std::random_access_iterator_tag,
-                                    const Expr *const> {
-    ConstExprIterator() : iterator_adaptor_base(nullptr) {}
-    ConstExprIterator(const Stmt *const *I) : iterator_adaptor_base(I) {}
-
-    reference operator*() const {
-      assert((*I)->getStmtClass() >= firstExprConstant &&
-             (*I)->getStmtClass() <= lastExprConstant);
-      return *reinterpret_cast<const Expr *const *>(I);
+    typename Base::value_type operator*() const {
+      return cast<T>(*this->I);
     }
   };
 
+  /// Const iterator for iterating over Stmt * arrays that contain only T *.
+  template <typename T>
+  using ConstCastIterator = CastIterator<T, const T *const, const Stmt *const>;
+
+  using ExprIterator = CastIterator<Expr>;
+  using ConstExprIterator = ConstCastIterator<Expr>;
+
 private:
   /// Whether statistic collection is enabled.
   static bool StatisticsEnabled;

Modified: cfe/trunk/lib/CodeGen/CGCoroutine.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCoroutine.cpp?rev=352925&r1=352924&r2=352925&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCoroutine.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCoroutine.cpp Fri Feb  1 13:58:17 2019
@@ -732,7 +732,7 @@ RValue CodeGenFunction::EmitCoroutineInt
     Args.push_back(llvm::ConstantTokenNone::get(getLLVMContext()));
     break;
   }
-  for (auto &Arg : E->arguments())
+  for (const Expr *Arg : E->arguments())
     Args.push_back(EmitScalarExpr(Arg));
 
   llvm::Value *F = CGM.getIntrinsic(IID);