revert most of the rest, but still expected to be without performance difference

Author: vtjnash

llvm/include/llvm/CodeGen/AsmPrinter.h

@@ -33,7 +33,6 @@
 namespace llvm {
 
 class AddrLabelMap;
-class AsmBasicPrinterHandler;
 class AsmPrinterHandler;
 class BasicBlock;
 class BlockAddress;
@@ -45,6 +44,7 @@ class DebugHandlerBase;
 class DIE;
 class DIEAbbrev;
 class DwarfDebug;
+class EHStreamer;
 class GCMetadataPrinter;
 class GCStrategy;
 class GlobalAlias;
@@ -188,14 +188,16 @@ class AsmPrinter : public MachineFunctionPass {
   /// For dso_local functions, the current $local alias for the function.
   MCSymbol *CurrentFnBeginLocal = nullptr;
 
-  /// A vector of all EH info emitters we should use. This vector
-  /// maintains ownership of the emitters.
-  SmallVector<std::unique_ptr<AsmBasicPrinterHandler>, 2> Handlers;
+  /// A handle to the EH info emitter (if present)
+  SmallVector<std::unique_ptr<AsmPrinterHandler>, 1>
+      EHHandlers; // only for EHHandler subtypes, but some c++ compilers will
+                  // incorrectly warn us if we declare that
 
   // A vector of all Debuginfo emitters we should use. Protected so that
-  // targets can add their own.
-  SmallVector<std::unique_ptr<AsmPrinterHandler>, 1> DebugHandlers;
-  size_t NumUserDebugHandlers = 0;
+  // targets can add their own. This vector maintains ownership of the
+  // emitters.
+  SmallVector<std::unique_ptr<AsmPrinterHandler>, 2> Handlers;
+  size_t NumUserHandlers = 0;
 
   StackMaps SM;
 

llvm/include/llvm/CodeGen/AsmPrinterHandler.h

@@ -30,9 +30,9 @@ typedef MCSymbol *ExceptionSymbolProvider(AsmPrinter *Asm,
 
 /// Collects and handles AsmPrinter objects required to build debug
 /// or EH information.
-class AsmBasicPrinterHandler {
+class AsmPrinterHandler {
 public:
-  virtual ~AsmBasicPrinterHandler();
+  virtual ~AsmPrinterHandler();
 
   virtual void beginModule(Module *M) {}
 
@@ -64,27 +64,22 @@ class AsmBasicPrinterHandler {
   /// immediately prior to markFunctionEnd.
   virtual void endBasicBlockSection(const MachineBasicBlock &MBB) {}
 
-  /// Emit target-specific EH funclet machinery.
-  virtual void beginFunclet(const MachineBasicBlock &MBB,
-                            MCSymbol *Sym = nullptr) {}
-  virtual void endFunclet() {}
-};
-
-class AsmPrinterHandler : public AsmBasicPrinterHandler {
-public:
-  virtual ~AsmPrinterHandler();
-
   /// For symbols that have a size designated (e.g. common symbols),
   /// this tracks that size.
   virtual void setSymbolSize(const MCSymbol *Sym, uint64_t Size) {}
 
   /// Process beginning of an instruction.
-  virtual void beginInstruction(const MachineInstr *MI) = 0;
+  virtual void beginInstruction(const MachineInstr *MI) {}
 
   /// Process end of an instruction.
-  virtual void endInstruction() = 0;
+  virtual void endInstruction() {}
 
   virtual void beginCodeAlignment(const MachineBasicBlock &MBB) {}
+
+  /// Emit target-specific EH funclet machinery.
+  virtual void beginFunclet(const MachineBasicBlock &MBB,
+                            MCSymbol *Sym = nullptr) {}
+  virtual void endFunclet() {}
 };
 
 } // End of namespace llvm

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -392,7 +392,7 @@ AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
 }
 
 AsmPrinter::~AsmPrinter() {
-  assert(!DD && DebugHandlers.size() == NumUserDebugHandlers &&
+  assert(!DD && Handlers.size() == NumUserHandlers &&
          "Debug/EH info didn't get finalized");
 }
 
@@ -561,11 +561,11 @@ bool AsmPrinter::doInitialization(Module &M) {
   if (MAI->doesSupportDebugInformation()) {
     bool EmitCodeView = M.getCodeViewFlag();
     if (EmitCodeView && TM.getTargetTriple().isOSWindows())
-      DebugHandlers.push_back(std::make_unique<CodeViewDebug>(this));
+      Handlers.push_back(std::make_unique<CodeViewDebug>(this));
     if (!EmitCodeView || M.getDwarfVersion()) {
       if (hasDebugInfo()) {
         DD = new DwarfDebug(this);
-        DebugHandlers.push_back(std::unique_ptr<DwarfDebug>(DD));
+        Handlers.push_back(std::unique_ptr<DwarfDebug>(DD));
       }
     }
   }
@@ -632,12 +632,12 @@ bool AsmPrinter::doInitialization(Module &M) {
 
   // Emit tables for any value of cfguard flag (i.e. cfguard=1 or cfguard=2).
   if (mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("cfguard")))
-    Handlers.push_back(std::make_unique<WinCFGuard>(this));
+    EHHandlers.push_back(std::make_unique<WinCFGuard>(this));
 
-  for (auto &Handler : DebugHandlers)
-    Handler->beginModule(&M);
   for (auto &Handler : Handlers)
     Handler->beginModule(&M);
+  for (auto &Handler : EHHandlers)
+    Handler->beginModule(&M);
 
   return false;
 }
@@ -784,7 +784,7 @@ void AsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
   // sections and expected to be contiguous (e.g. ObjC metadata).
   const Align Alignment = getGVAlignment(GV, DL);
 
-  for (auto &Handler : DebugHandlers)
+  for (auto &Handler : Handlers)
     Handler->setSymbolSize(GVSym, Size);
 
   // Handle common symbols
@@ -1054,14 +1054,14 @@ void AsmPrinter::emitFunctionHeader() {
   }
 
   // Emit pre-function debug and/or EH information.
-  for (auto &Handler : DebugHandlers) {
+  for (auto &Handler : Handlers) {
     Handler->beginFunction(MF);
     Handler->beginBasicBlockSection(MF->front());
   }
-  for (auto &Handler : Handlers)
+  for (auto &Handler : EHHandlers) {
     Handler->beginFunction(MF);
-  for (auto &Handler : Handlers)
     Handler->beginBasicBlockSection(MF->front());
+  }
 
   // Emit the prologue data.
   if (F.hasPrologueData())
@@ -1836,7 +1836,7 @@ void AsmPrinter::emitFunctionBody() {
       if (MDNode *MD = MI.getPCSections())
         emitPCSectionsLabel(*MF, *MD);
 
-      for (auto &Handler : DebugHandlers)
+      for (auto &Handler : Handlers)
         Handler->beginInstruction(&MI);
 
       if (isVerbose())
@@ -1952,7 +1952,7 @@ void AsmPrinter::emitFunctionBody() {
       if (MCSymbol *S = MI.getPostInstrSymbol())
         OutStreamer->emitLabel(S);
 
-      for (auto &Handler : DebugHandlers)
+      for (auto &Handler : Handlers)
         Handler->endInstruction();
     }
 
@@ -2089,12 +2089,12 @@ void AsmPrinter::emitFunctionBody() {
   // Call endBasicBlockSection on the last block now, if it wasn't already
   // called.
   if (!MF->back().isEndSection()) {
-    for (auto &Handler : DebugHandlers)
-      Handler->endBasicBlockSection(MF->back());
     for (auto &Handler : Handlers)
       Handler->endBasicBlockSection(MF->back());
+    for (auto &Handler : EHHandlers)
+      Handler->endBasicBlockSection(MF->back());
   }
-  for (auto &Handler : Handlers)
+  for (auto &Handler : EHHandlers)
     Handler->markFunctionEnd();
   // Update the end label of the entry block's section.
   MBBSectionRanges[MF->front().getSectionID()].EndLabel = CurrentFnEnd;
@@ -2103,10 +2103,10 @@ void AsmPrinter::emitFunctionBody() {
   emitJumpTableInfo();
 
   // Emit post-function debug and/or EH information.
-  for (auto &Handler : DebugHandlers)
-    Handler->endFunction(MF);
   for (auto &Handler : Handlers)
     Handler->endFunction(MF);
+  for (auto &Handler : EHHandlers)
+    Handler->endFunction(MF);
 
   // Emit section containing BB address offsets and their metadata, when
   // BB labels are requested for this function. Skip empty functions.
@@ -2583,17 +2583,16 @@ bool AsmPrinter::doFinalization(Module &M) {
     emitGlobalIFunc(M, IFunc);
 
   // Finalize debug and EH information.
-  for (auto &Handler : DebugHandlers)
-    Handler->endModule();
   for (auto &Handler : Handlers)
     Handler->endModule();
+  for (auto &Handler : EHHandlers)
+    Handler->endModule();
 
   // This deletes all the ephemeral handlers that AsmPrinter added, while
   // keeping all the user-added handlers alive until the AsmPrinter is
   // destroyed.
-  Handlers.clear();
-  DebugHandlers.erase(DebugHandlers.begin() + NumUserDebugHandlers,
-                      DebugHandlers.end());
+  EHHandlers.clear();
+  Handlers.erase(Handlers.begin() + NumUserHandlers, Handlers.end());
   DD = nullptr;
 
   // If the target wants to know about weak references, print them all.
@@ -4196,6 +4195,10 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
       Handler->endFunclet();
       Handler->beginFunclet(MBB);
     }
+    for (auto &Handler : EHHandlers) {
+      Handler->endFunclet();
+      Handler->beginFunclet(MBB);
+    }
   }
 
   // Switch to a new section if this basic block must begin a section. The
@@ -4208,7 +4211,7 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
     CurrentSectionBeginSym = MBB.getSymbol();
   }
 
-  for (auto &Handler : DebugHandlers)
+  for (auto &Handler : Handlers)
     Handler->beginCodeAlignment(MBB);
 
   // Emit an alignment directive for this block, if needed.
@@ -4268,21 +4271,21 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
   // if it begins a section (Entry block call is handled separately, next to
   // beginFunction).
   if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
-    for (auto &Handler : DebugHandlers)
-      Handler->beginBasicBlockSection(MBB);
     for (auto &Handler : Handlers)
       Handler->beginBasicBlockSection(MBB);
+    for (auto &Handler : EHHandlers)
+      Handler->beginBasicBlockSection(MBB);
   }
 }
 
 void AsmPrinter::emitBasicBlockEnd(const MachineBasicBlock &MBB) {
   // Check if CFI information needs to be updated for this MBB with basic block
   // sections.
   if (MBB.isEndSection()) {
-    for (auto &Handler : DebugHandlers)
-      Handler->endBasicBlockSection(MBB);
     for (auto &Handler : Handlers)
       Handler->endBasicBlockSection(MBB);
+    for (auto &Handler : EHHandlers)
+      Handler->endBasicBlockSection(MBB);
   }
 }
 
@@ -4411,15 +4414,14 @@ void AsmPrinter::emitStackMaps() {
 
 void AsmPrinter::addAsmPrinterHandler(
     std::unique_ptr<AsmPrinterHandler> Handler) {
-  DebugHandlers.insert(DebugHandlers.begin(), std::move(Handler));
-  NumUserDebugHandlers++;
+  Handlers.insert(Handlers.begin(), std::move(Handler));
+  NumUserHandlers++;
 }
 
 /// Pin vtables to this file.
-AsmBasicPrinterHandler::~AsmBasicPrinterHandler() = default;
 AsmPrinterHandler::~AsmPrinterHandler() = default;
 
-void AsmBasicPrinterHandler::markFunctionEnd() {}
+void AsmPrinterHandler::markFunctionEnd() {}
 
 // In the binary's "xray_instr_map" section, an array of these function entries
 // describes each instrumentation point.  When XRay patches your code, the index

llvm/lib/CodeGen/AsmPrinter/EHStreamer.h

@@ -27,7 +27,7 @@ class MCSymbol;
 template <typename T> class SmallVectorImpl;
 
 /// Emits exception handling directives.
-class LLVM_LIBRARY_VISIBILITY EHStreamer : public AsmBasicPrinterHandler {
+class LLVM_LIBRARY_VISIBILITY EHStreamer : public AsmPrinterHandler {
 protected:
   /// Target of directive emission.
   AsmPrinter *Asm;

llvm/lib/CodeGen/AsmPrinter/WinCFGuard.h

@@ -14,13 +14,13 @@
 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
 #define LLVM_LIB_CODEGEN_ASMPRINTER_WINCFGUARD_H
 
-#include "llvm/CodeGen/AsmPrinterHandler.h"
+#include "EHStreamer.h"
 #include "llvm/Support/Compiler.h"
 #include <vector>
 
 namespace llvm {
 
-class LLVM_LIBRARY_VISIBILITY WinCFGuard : public AsmBasicPrinterHandler {
+class LLVM_LIBRARY_VISIBILITY WinCFGuard : public AsmPrinterHandler {
   /// Target of directive emission.
   AsmPrinter *Asm;
   std::vector<const MCSymbol *> LongjmpTargets;

llvm/lib/Target/BPF/BPFAsmPrinter.cpp

@@ -60,7 +60,7 @@ bool BPFAsmPrinter::doInitialization(Module &M) {
   // Only emit BTF when debuginfo available.
   if (MAI->doesSupportDebugInformation() && !M.debug_compile_units().empty()) {
     BTF = new BTFDebug(this);
-    DebugHandlers.push_back(std::unique_ptr<BTFDebug>(BTF));
+    Handlers.push_back(std::unique_ptr<BTFDebug>(BTF));
   }
 
   return false;