[PATCH] D136725: [Lex] Stop allocating/deallocating MacroInfo on a linked list. NFC

[Sam McCall via Phabricator via cfe-commits]

sammccall created this revision.
sammccall added a reviewer: hokein.
Herald added a project: All.
sammccall requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

This list was originally used for to make sure MacroInfo's clever memory
management got called (1f1e4bdbf7815c), but that was
simplified in 73a29662b9bf640a and 1f1e4bdbf7815c, and there's nothing left.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D136725

Files:
  clang/include/clang/Lex/MacroInfo.h
  clang/include/clang/Lex/Preprocessor.h
  clang/lib/Lex/PPDirectives.cpp
  clang/lib/Lex/Preprocessor.cpp


Index: clang/lib/Lex/Preprocessor.cpp
===================================================================
--- clang/lib/Lex/Preprocessor.cpp
+++ clang/lib/Lex/Preprocessor.cpp
@@ -165,12 +165,6 @@
 
   IncludeMacroStack.clear();
 
-  // Destroy any macro definitions.
-  while (MacroInfoChain *I = MIChainHead) {
-    MIChainHead = I->Next;
-    I->~MacroInfoChain();
-  }
-
   // Free any cached macro expanders.
   // This populates MacroArgCache, so all TokenLexers need to be destroyed
   // before the code below that frees up the MacroArgCache list.
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -57,9 +57,8 @@
 //===----------------------------------------------------------------------===//
 
 MacroInfo *Preprocessor::AllocateMacroInfo(SourceLocation L) {
-  auto *MIChain = new (BP) MacroInfoChain{L, MIChainHead};
-  MIChainHead = MIChain;
-  return &MIChain->MI;
+  static_assert(std::is_trivially_destructible_v<MacroInfo>, "");
+  return new (BP) MacroInfo(L);
 }
 
 DefMacroDirective *Preprocessor::AllocateDefMacroDirective(MacroInfo *MI,
Index: clang/include/clang/Lex/Preprocessor.h
===================================================================
--- clang/include/clang/Lex/Preprocessor.h
+++ clang/include/clang/Lex/Preprocessor.h
@@ -1011,15 +1011,6 @@
   /// invoked (at which point the last position is popped).
   std::vector<CachedTokensTy::size_type> BacktrackPositions;
 
-  struct MacroInfoChain {
-    MacroInfo MI;
-    MacroInfoChain *Next;
-  };
-
-  /// MacroInfos are managed as a chain for easy disposal.  This is the head
-  /// of that list.
-  MacroInfoChain *MIChainHead = nullptr;
-
   /// True if \p Preprocessor::SkipExcludedConditionalBlock() is running.
   /// This is used to guard against calling this function recursively.
   ///
Index: clang/include/clang/Lex/MacroInfo.h
===================================================================
--- clang/include/clang/Lex/MacroInfo.h
+++ clang/include/clang/Lex/MacroInfo.h
@@ -117,9 +117,8 @@
   /// Whether this macro was used as header guard.
   bool UsedForHeaderGuard : 1;
 
-  // Only the Preprocessor gets to create and destroy these.
+  // Only the Preprocessor gets to create these.
   MacroInfo(SourceLocation DefLoc);
-  ~MacroInfo() = default;
 
 public:
   /// Return the location that the macro was defined at.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D136725.470664.patch
Type: text/x-patch
Size: 2456 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20221026/02dcc8e3/attachment.bin>