[llvm] r315080 - [MC] Use unique_ptr to manage WinFrameInfos, NFC

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Fri Oct  6 10:21:49 2017
New Revision: 315080

URL: http://llvm.org/viewvc/llvm-project?rev=315080&view=rev
Log:
[MC] Use unique_ptr to manage WinFrameInfos, NFC

The FrameInfo cannot be stored directly in the vector because chained
frames may refer to parent frames, so we need pointers that are stable
across a vector resize.

Modified:
    llvm/trunk/include/llvm/MC/MCStreamer.h
    llvm/trunk/lib/MC/MCStreamer.cpp
    llvm/trunk/lib/MC/MCWin64EH.cpp

Modified: llvm/trunk/include/llvm/MC/MCStreamer.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCStreamer.h?rev=315080&r1=315079&r2=315080&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCStreamer.h (original)
+++ llvm/trunk/include/llvm/MC/MCStreamer.h Fri Oct  6 10:21:49 2017
@@ -176,7 +176,10 @@ class MCStreamer {
   MCSymbol *EmitCFILabel();
   MCSymbol *EmitCFICommon();
 
-  std::vector<WinEH::FrameInfo *> WinFrameInfos;
+  /// Similar to DwarfFrameInfos, but for SEH unwind info. Chained frames may
+  /// refer to each other, so use std::unique_ptr to provide pointer stability.
+  std::vector<std::unique_ptr<WinEH::FrameInfo>> WinFrameInfos;
+
   WinEH::FrameInfo *CurrentWinFrameInfo;
   void EnsureValidWinFrameInfo();
 
@@ -238,7 +241,7 @@ public:
   bool hasUnfinishedDwarfFrameInfo();
 
   unsigned getNumWinFrameInfos() { return WinFrameInfos.size(); }
-  ArrayRef<WinEH::FrameInfo *> getWinFrameInfos() const {
+  ArrayRef<std::unique_ptr<WinEH::FrameInfo>> getWinFrameInfos() const {
     return WinFrameInfos;
   }
 

Modified: llvm/trunk/lib/MC/MCStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCStreamer.cpp?rev=315080&r1=315079&r2=315080&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCStreamer.cpp Fri Oct  6 10:21:49 2017
@@ -56,17 +56,12 @@ MCStreamer::MCStreamer(MCContext &Ctx)
   SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
 }
 
-MCStreamer::~MCStreamer() {
-  for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
-    delete WinFrameInfos[i];
-}
+MCStreamer::~MCStreamer() {}
 
 void MCStreamer::reset() {
   DwarfFrameInfos.clear();
-  for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
-    delete WinFrameInfos[i];
-  WinFrameInfos.clear();
   CurrentWinFrameInfo = nullptr;
+  WinFrameInfos.clear();
   SymbolOrdering.clear();
   SectionStack.clear();
   SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
@@ -538,8 +533,9 @@ void MCStreamer::EmitWinCFIStartProc(con
 
   MCSymbol *StartProc = EmitCFILabel();
 
-  WinFrameInfos.push_back(new WinEH::FrameInfo(Symbol, StartProc));
-  CurrentWinFrameInfo = WinFrameInfos.back();
+  WinFrameInfos.emplace_back(
+      llvm::make_unique<WinEH::FrameInfo>(Symbol, StartProc));
+  CurrentWinFrameInfo = WinFrameInfos.back().get();
   CurrentWinFrameInfo->TextSection = getCurrentSectionOnly();
 }
 
@@ -557,9 +553,9 @@ void MCStreamer::EmitWinCFIStartChained(
 
   MCSymbol *StartProc = EmitCFILabel();
 
-  WinFrameInfos.push_back(new WinEH::FrameInfo(CurrentWinFrameInfo->Function,
-                                               StartProc, CurrentWinFrameInfo));
-  CurrentWinFrameInfo = WinFrameInfos.back();
+  WinFrameInfos.emplace_back(llvm::make_unique<WinEH::FrameInfo>(
+      CurrentWinFrameInfo->Function, StartProc, CurrentWinFrameInfo));
+  CurrentWinFrameInfo = WinFrameInfos.back().get();
   CurrentWinFrameInfo->TextSection = getCurrentSectionOnly();
 }
 

Modified: llvm/trunk/lib/MC/MCWin64EH.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCWin64EH.cpp?rev=315080&r1=315079&r2=315080&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCWin64EH.cpp (original)
+++ llvm/trunk/lib/MC/MCWin64EH.cpp Fri Oct  6 10:21:49 2017
@@ -220,17 +220,17 @@ static void EmitUnwindInfo(MCStreamer &s
 
 void llvm::Win64EH::UnwindEmitter::Emit(MCStreamer &Streamer) const {
   // Emit the unwind info structs first.
-  for (WinEH::FrameInfo *CFI : Streamer.getWinFrameInfos()) {
+  for (const auto &CFI : Streamer.getWinFrameInfos()) {
     MCSection *XData = Streamer.getAssociatedXDataSection(CFI->TextSection);
     Streamer.SwitchSection(XData);
-    ::EmitUnwindInfo(Streamer, CFI);
+    ::EmitUnwindInfo(Streamer, CFI.get());
   }
 
   // Now emit RUNTIME_FUNCTION entries.
-  for (WinEH::FrameInfo *CFI : Streamer.getWinFrameInfos()) {
+  for (const auto &CFI : Streamer.getWinFrameInfos()) {
     MCSection *PData = Streamer.getAssociatedPDataSection(CFI->TextSection);
     Streamer.SwitchSection(PData);
-    EmitRuntimeFunction(Streamer, CFI);
+    EmitRuntimeFunction(Streamer, CFI.get());
   }
 }