From 18e578687b025e38731b28c88c9f518c84a0b6a8 Mon Sep 17 00:00:00 2001
From: Neil Dhar <neildhar@fb.com>
Date: Tue, 29 Sep 2020 11:10:17 -0700
Subject: [PATCH] Clean up allocLongLived in GenGC and MallocGC

Summary: Remove allocLongLived APIs from GenGC and MallocGC.

Reviewed By: dulinriley

Differential Revision: D23833526

fbshipit-source-id: d8422dd92b1a0ab7f1b1e011842c8a629d09d8f3
---
 include/hermes/VM/GCBase.h   |  7 -------
 include/hermes/VM/GenGCNC.h  | 12 ++++++------
 include/hermes/VM/MallocGC.h | 20 +++-----------------
 lib/VM/gcs/MallocGC.cpp      |  2 --
 4 files changed, 9 insertions(+), 32 deletions(-)

diff --git a/include/hermes/VM/GCBase.h b/include/hermes/VM/GCBase.h
index 1c243cc6e65..5de70f2ac83 100644
--- a/include/hermes/VM/GCBase.h
+++ b/include/hermes/VM/GCBase.h
@@ -79,13 +79,6 @@ class Deserializer;
 ///             HasFinalizer hasFinalizer = HasFinalizer::No>
 ///   CallResult<GCCell *> alloc(const VTable *vt, uint32_t size);
 ///
-/// Like the above, but if the GC makes a distinction between short- and
-/// long-lived objects, allocates an object that is expected to be
-/// long-lived.  Does not allow specification of fixed-sizeness.
-///
-///   template <HasFinalizer hasFinalizer = HasFinalizer::No>
-///   CallResult<GCCell *> allocLongLived(const VTable *vt, uint32_t size);
-///
 /// Allocate a new cell of type \p T and size \p size using the APIs above.
 /// Instantiate an object of type \p T in the newly allocated cell, using
 /// \p args as the arguments to its constructor.
diff --git a/include/hermes/VM/GenGCNC.h b/include/hermes/VM/GenGCNC.h
index 33b0c9d01d2..9cd9dec7c37 100644
--- a/include/hermes/VM/GenGCNC.h
+++ b/include/hermes/VM/GenGCNC.h
@@ -142,12 +142,6 @@ class GenGC final : public GCBase {
   debugAllocRandomize(uint32_t sz, HasFinalizer hasFinalizer, bool fixedSize);
 #endif
 
-  /// Like alloc above, but the resulting object is expected to be long-lived.
-  /// Allocate directly in the old generation (doing a full collection if
-  /// necessary to create room).
-  template <HasFinalizer hasFinalizer = HasFinalizer::No>
-  inline void *allocLongLived(uint32_t size);
-
   /// Allocate a new cell of the specified size \p size by calling alloc.
   /// Instantiate an object of type T with constructor arguments \p args in the
   /// newly allocated cell.
@@ -519,6 +513,12 @@ class GenGC final : public GCBase {
   /// arguments.
   void *allocSlow(uint32_t sz, bool fixedSize, HasFinalizer hasFinalizer);
 
+  /// Like alloc above, but the resulting object is expected to be long-lived.
+  /// Allocate directly in the old generation (doing a full collection if
+  /// necessary to create room).
+  template <HasFinalizer hasFinalizer = HasFinalizer::No>
+  inline void *allocLongLived(uint32_t size);
+
   /// The given pointer value is being written at the given loc (required to
   /// be in the heap).  The value is may be null.  Execute a write
   /// barrier.  The \p hv argument indicates whether this is being
diff --git a/include/hermes/VM/MallocGC.h b/include/hermes/VM/MallocGC.h
index 029ebbbd71b..35586c6daa3 100644
--- a/include/hermes/VM/MallocGC.h
+++ b/include/hermes/VM/MallocGC.h
@@ -170,12 +170,6 @@ class MallocGC final : public GCBase {
   /// declared.
   void collectBeforeAlloc(std::string cause, uint32_t size);
 
-  /// Same as above, but tries to allocate in a long lived area of the heap.
-  /// Use this when the object is known to last for a long period of time.
-  /// NOTE: this does nothing different for MallocGC, but does for GenGC.
-  template <HasFinalizer hasFinalizer = HasFinalizer::No>
-  inline void *allocLongLived(uint32_t size);
-
   /// Allocate a new cell of the specified size \p size by calling alloc.
   /// Instantiate an object of type T with constructor arguments \p args in the
   /// newly allocated cell.
@@ -370,13 +364,6 @@ inline void *MallocGC::alloc(uint32_t size) {
   return mem;
 }
 
-template <HasFinalizer hasFinalizer>
-inline void *MallocGC::allocLongLived(uint32_t size) {
-  // Since there is no old generation in this collector, forward to the normal
-  // allocation.
-  return alloc<true, hasFinalizer>(size);
-}
-
 inline bool MallocGC::canAllocExternalMemory(uint32_t size) {
   return size <= maxSize_;
 }
@@ -388,10 +375,9 @@ template <
     LongLived longLived,
     class... Args>
 inline T *MallocGC::makeA(uint32_t size, Args &&... args) {
-  // TODO: Once all callers are using makeA, remove allocLongLived.
-  void *mem = longLived == LongLived::Yes
-      ? allocLongLived<hasFinalizer>(size)
-      : alloc<fixedSize, hasFinalizer>(size);
+  // Since there is no old generation in this collector, always forward to the
+  // normal allocation.
+  void *mem = alloc<fixedSize, hasFinalizer>(size);
   return new (mem) T(std::forward<Args>(args)...);
 }
 
diff --git a/lib/VM/gcs/MallocGC.cpp b/lib/VM/gcs/MallocGC.cpp
index c986736836d..a3348fa4668 100644
--- a/lib/VM/gcs/MallocGC.cpp
+++ b/lib/VM/gcs/MallocGC.cpp
@@ -620,8 +620,6 @@ template void *MallocGC::alloc</*FixedSize*/ true, HasFinalizer::No>(
     uint32_t size);
 template void *MallocGC::alloc</*FixedSize*/ false, HasFinalizer::No>(
     uint32_t size);
-template void *MallocGC::allocLongLived<HasFinalizer::Yes>(uint32_t size);
-template void *MallocGC::allocLongLived<HasFinalizer::No>(uint32_t size);
 /// @}
 
 } // namespace vm