Extract the method to begin and end a fragment in AsmPrinterHandler in their own method. NFC

Summary: This is extracted from D17555

Reviewers: davidxl, reames, sanjoy, MatzeB, pete

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D17580

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262058 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/AsmPrinterHandler.h

@@ -19,11 +19,14 @@
 
 namespace llvm {
 
+class AsmPrinter;
 class MachineBasicBlock;
 class MachineFunction;
 class MachineInstr;
 class MCSymbol;
 
+typedef MCSymbol *ExceptionSymbolProvider(AsmPrinter *Asm);
+
 /// \brief Collects and handles AsmPrinter objects required to build debug
 /// or EH information.
 class AsmPrinterHandler {
@@ -51,6 +54,10 @@ public:
   /// beginFunction at all.
   virtual void endFunction(const MachineFunction *MF) = 0;
 
+  virtual void beginFragment(const MachineBasicBlock *MBB,
+                             ExceptionSymbolProvider ESP) {}
+  virtual void endFragment() {}
+
   /// \brief Emit target-specific EH funclet machinery.
   virtual void beginFunclet(const MachineBasicBlock &MBB,
                             MCSymbol *Sym = nullptr) {}

lib/CodeGen/AsmPrinter/DwarfCFIException.cpp

@@ -43,8 +43,7 @@ DwarfCFIExceptionBase::DwarfCFIExceptionBase(AsmPrinter *A)
     : EHStreamer(A), shouldEmitCFI(false) {}
 
 void DwarfCFIExceptionBase::markFunctionEnd() {
-  if (shouldEmitCFI)
-    Asm->OutStreamer->EmitCFIEndProc();
+  endFragment();
 
   if (MMI->getLandingPads().empty())
     return;
@@ -53,10 +52,15 @@ void DwarfCFIExceptionBase::markFunctionEnd() {
   MMI->TidyLandingPads();
 }
 
+void DwarfCFIExceptionBase::endFragment() {
+  if (shouldEmitCFI)
+    Asm->OutStreamer->EmitCFIEndProc();
+}
+
 DwarfCFIException::DwarfCFIException(AsmPrinter *A)
     : DwarfCFIExceptionBase(A), shouldEmitPersonality(false),
-      shouldEmitLSDA(false), shouldEmitMoves(false),
-      moveTypeModule(AsmPrinter::CFI_M_None) {}
+      shouldEmitLSDA(false), forceEmitPersonality(false),
+      shouldEmitMoves(false), moveTypeModule(AsmPrinter::CFI_M_None) {}
 
 DwarfCFIException::~DwarfCFIException() {}
 
@@ -86,6 +90,10 @@ void DwarfCFIException::endModule() {
   }
 }
 
+static MCSymbol *getExceptionSym(AsmPrinter *Asm) {
+  return Asm->getCurExceptionSym();
+}
+
 void DwarfCFIException::beginFunction(const MachineFunction *MF) {
   shouldEmitMoves = shouldEmitPersonality = shouldEmitLSDA = false;
   const Function *F = MF->getFunction();
@@ -109,7 +117,7 @@ void DwarfCFIException::beginFunction(const MachineFunction *MF) {
     Per = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
 
   // Emit a personality function even when there are no landing pads
-  bool forceEmitPersonality =
+  forceEmitPersonality =
       // ...if a personality function is explicitly specified
       F->hasPersonalityFn() &&
       // ... and it's not known to be a noop in the absence of invokes
@@ -127,6 +135,11 @@ void DwarfCFIException::beginFunction(const MachineFunction *MF) {
     LSDAEncoding != dwarf::DW_EH_PE_omit;
 
   shouldEmitCFI = shouldEmitPersonality || shouldEmitMoves;
+  beginFragment(&*MF->begin(), getExceptionSym);
+}
+
+void DwarfCFIException::beginFragment(const MachineBasicBlock *MBB,
+                                      ExceptionSymbolProvider ESP) {
   if (!shouldEmitCFI)
     return;
 
@@ -136,20 +149,24 @@ void DwarfCFIException::beginFunction(const MachineFunction *MF) {
   if (!shouldEmitPersonality)
     return;
 
+  auto *F = MBB->getParent()->getFunction();
+  auto *P = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
+  assert(P && "Expected personality function");
+
   // If we are forced to emit this personality, make sure to record
   // it because it might not appear in any landingpad
   if (forceEmitPersonality)
-    MMI->addPersonality(Per);
+    MMI->addPersonality(P);
 
+  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
+  unsigned PerEncoding = TLOF.getPersonalityEncoding();
   const MCSymbol *Sym =
-      TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
+      TLOF.getCFIPersonalitySymbol(P, *Asm->Mang, Asm->TM, MMI);
   Asm->OutStreamer->EmitCFIPersonality(Sym, PerEncoding);
 
   // Provide LSDA information.
-  if (!shouldEmitLSDA)
-    return;
-
-  Asm->OutStreamer->EmitCFILsda(Asm->getCurExceptionSym(), LSDAEncoding);
+  if (shouldEmitLSDA)
+    Asm->OutStreamer->EmitCFILsda(ESP(Asm), TLOF.getLSDAEncoding());
 }
 
 /// endFunction - Gather and emit post-function exception information.

lib/CodeGen/AsmPrinter/DwarfException.h

@@ -16,6 +16,7 @@
 
 #include "EHStreamer.h"
 #include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/MC/MCDwarf.h"
 
 namespace llvm {
 class MachineFunction;
@@ -29,12 +30,16 @@ protected:
   bool shouldEmitCFI;
 
   void markFunctionEnd() override;
+  void endFragment() override;
 };
 
 class LLVM_LIBRARY_VISIBILITY DwarfCFIException : public DwarfCFIExceptionBase {
   /// Per-function flag to indicate if .cfi_personality should be emitted.
   bool shouldEmitPersonality;
 
+  /// Per-function flag to indicate if .cfi_personality must be emitted.
+  bool forceEmitPersonality;
+
   /// Per-function flag to indicate if .cfi_lsda should be emitted.
   bool shouldEmitLSDA;
 
@@ -59,6 +64,9 @@ public:
 
   /// Gather and emit post-function exception information.
   void endFunction(const MachineFunction *) override;
+
+  void beginFragment(const MachineBasicBlock *MBB,
+                     ExceptionSymbolProvider ESP) override;
 };
 
 class LLVM_LIBRARY_VISIBILITY ARMException : public DwarfCFIExceptionBase {

lib/CodeGen/AsmPrinter/EHStreamer.h

@@ -22,7 +22,6 @@ struct LandingPadInfo;
 class MachineModuleInfo;
 class MachineInstr;
 class MachineFunction;
-class AsmPrinter;
 class MCSymbol;
 class MCSymbolRefExpr;