From 8331a7ff3c9b1b187939b8ec3c34c81c0029c11d Mon Sep 17 00:00:00 2001
From: "John F. Carr" <jfc@mit.edu>
Date: Fri, 23 Jan 2026 09:53:05 -0700
Subject: [PATCH 1/4] Keyword renaming is not needed if __cilk >= 301

---
 include/cilk/cilk.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/cilk/cilk.h b/include/cilk/cilk.h
index 7014987a..c5fcde2f 100644
--- a/include/cilk/cilk.h
+++ b/include/cilk/cilk.h
@@ -1,6 +1,8 @@
 #ifndef _CILK_H
 #define  _CILK_H
 
+#if __cilk < 301
+
 #define cilk_spawn _Cilk_spawn
 #define cilk_sync  _Cilk_sync
 #define cilk_for   _Cilk_for
@@ -8,4 +10,6 @@
 
 #define cilk_reducer _Hyperobject
 
+#endif
+
 #endif /* _CILK_H */

From 31adb1b8f3d76ff962b926facf85715026c41207 Mon Sep 17 00:00:00 2001
From: "John F. Carr" <jfc@mit.edu>
Date: Fri, 23 Jan 2026 09:53:57 -0700
Subject: [PATCH 2/4] Rename holder.h to holder as a C++-only header

---
 include/CMakeLists.txt            | 2 +-
 include/cilk/{holder.h => holder} | 6 +-----
 2 files changed, 2 insertions(+), 6 deletions(-)
 rename include/cilk/{holder.h => holder} (79%)

diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index b6ff20c5..102ef44d 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -2,7 +2,7 @@ set(cilk_header_files
   cilk/cilk.h
   cilk/cilk_api.h
   cilk/cilk_stub.h
-  cilk/holder.h
+  cilk/holder
   cilk/opadd_reducer.h
   cilk/ostream_reducer.h
   cilk/reducer)
diff --git a/include/cilk/holder.h b/include/cilk/holder
similarity index 79%
rename from include/cilk/holder.h
rename to include/cilk/holder
index 2f36e770..1a8a743d 100644
--- a/include/cilk/holder.h
+++ b/include/cilk/holder
@@ -1,8 +1,6 @@
 #ifndef _HOLDER_H
 #define _HOLDER_H
 
-#ifdef __cplusplus
-
 #include <type_traits>
 
 namespace cilk {
@@ -16,10 +14,8 @@ template <typename A> static void reduce(void *left, void *right) {
 }
 
 template <typename A>
-using holder = A _Hyperobject(init<A>, reduce<A>);
+using holder = A cilk_reducer(init<A>, reduce<A>);
 
 } // namespace cilk
 
-#endif // __cplusplus
-
 #endif // _HOLDER_H

From 4f647c52acc32841f356ea6be50bf69bb4fffb09 Mon Sep 17 00:00:00 2001
From: "John F. Carr" <jfc@mit.edu>
Date: Fri, 23 Jan 2026 09:55:15 -0700
Subject: [PATCH 3/4] Rename opadd_reducer.h to opadd_reducer as a C++-only
 header

---
 include/CMakeLists.txt                          | 2 +-
 include/cilk/{opadd_reducer.h => opadd_reducer} | 6 +-----
 2 files changed, 2 insertions(+), 6 deletions(-)
 rename include/cilk/{opadd_reducer.h => opadd_reducer} (75%)

diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 102ef44d..8f6c4925 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -3,7 +3,7 @@ set(cilk_header_files
   cilk/cilk_api.h
   cilk/cilk_stub.h
   cilk/holder
-  cilk/opadd_reducer.h
+  cilk/opadd_reducer
   cilk/ostream_reducer.h
   cilk/reducer)
 
diff --git a/include/cilk/opadd_reducer.h b/include/cilk/opadd_reducer
similarity index 75%
rename from include/cilk/opadd_reducer.h
rename to include/cilk/opadd_reducer
index be7c2696..b8118ff2 100644
--- a/include/cilk/opadd_reducer.h
+++ b/include/cilk/opadd_reducer
@@ -1,8 +1,6 @@
 #ifndef _OPADD_REDUCER_H
 #define _OPADD_REDUCER_H
 
-#ifdef __cplusplus
-
 namespace cilk {
 
 template <typename T> static void zero(void *v) {
@@ -13,10 +11,8 @@ template <typename T> static void plus(void *l, void *r) {
     *static_cast<T *>(l) += *static_cast<T *>(r);
 }
 
-template <typename T> using opadd_reducer = T _Hyperobject(zero<T>, plus<T>);
+template <typename T> using opadd_reducer = T cilk_reducer(zero<T>, plus<T>);
 
 } // namespace cilk
 
-#endif // #ifdef __cplusplus
-
 #endif // _OPADD_REDUCER_H

From 371ab33e3c190a8db4bc3824cfebcb3e48b798ee Mon Sep 17 00:00:00 2001
From: "John F. Carr" <jfc@mit.edu>
Date: Fri, 23 Jan 2026 10:03:57 -0700
Subject: [PATCH 4/4] Rename ostream_reducer.h to ostream_reducer as a C++-only
 header

---
 include/CMakeLists.txt                              | 2 +-
 include/cilk/{ostream_reducer.h => ostream_reducer} | 8 ++------
 2 files changed, 3 insertions(+), 7 deletions(-)
 rename include/cilk/{ostream_reducer.h => ostream_reducer} (91%)

diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 8f6c4925..25bc294f 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -4,7 +4,7 @@ set(cilk_header_files
   cilk/cilk_stub.h
   cilk/holder
   cilk/opadd_reducer
-  cilk/ostream_reducer.h
+  cilk/ostream_reducer
   cilk/reducer)
 
 set(output_dir ${CHEETAH_OUTPUT_DIR}/include)
diff --git a/include/cilk/ostream_reducer.h b/include/cilk/ostream_reducer
similarity index 91%
rename from include/cilk/ostream_reducer.h
rename to include/cilk/ostream_reducer
index 88113132..07449c17 100644
--- a/include/cilk/ostream_reducer.h
+++ b/include/cilk/ostream_reducer
@@ -1,8 +1,6 @@
 #ifndef _OSTREAM_REDUCER_H
 #define _OSTREAM_REDUCER_H
 
-#ifdef __cplusplus
-
 #include <ostream>
 #include <sstream>
 
@@ -64,11 +62,9 @@ class ostream_view : public std::basic_ostream<Char, Traits>
 
 template<typename Char, typename Traits = std::char_traits<Char>>
   using ostream_reducer = ostream_view<Char, Traits>
-    _Hyperobject(&ostream_view<Char, std::char_traits<Char>>::identity,
-                 &ostream_view<Char, std::char_traits<Char>>::reduce);
+    cilk_reducer(&ostream_view<Char, Traits>::identity,
+                 &ostream_view<Char, Traits>::reduce);
 
 } // namespace cilk
 
-#endif // __cplusplus
-
 #endif // _OSTREAM_REDUCER_H