Centralize handling of the eh_begin and eh_end labels.

This removes a bit of duplicated code and more importantly, remembers the
labels so that they don't need to be looked up by name.

This in turn allows for any name to be used and avoids a crash if the name
we wanted was already taken.

llvm-svn: 230772

5 files changed, 28 insertions, 33 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
index 6fe75ad82d2..119aa3a18c4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
@@ -58,8 +58,6 @@ void ARMException::endModule() {
 void ARMException::beginFunction(const MachineFunction *MF) {
   if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
     getTargetStreamer().emitFnStart();
-  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
-                                                Asm->getFunctionNumber()));
   // See if we need call frame info.
   AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
   assert(MoveType != AsmPrinter::CFI_M_EH &&
@@ -84,8 +82,6 @@ void ARMException::endFunction(const MachineFunction *) {
       MMI->getLandingPads().empty())
     ATS.emitCantUnwind();
   else {
-    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
-                                                  Asm->getFunctionNumber()));
     if (!MMI->getLandingPads().empty()) {
       // Emit references to personality.
       if (const Function *Personality = MMI->getPersonality()) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 988381d745a..b94278fae07 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -109,6 +109,8 @@ AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
   LI = nullptr;
   MF = nullptr;
   CurrentFnSym = CurrentFnSymForSize = nullptr;
+  CurrentFnBegin = nullptr;
+  CurrentFnEnd = nullptr;
   GCMetadataPrinters = nullptr;
   VerboseAsm = OutStreamer.isVerboseAsm();
 }
@@ -554,6 +556,19 @@ void AsmPrinter::EmitFunctionHeader() {
     OutStreamer.EmitLabel(DeadBlockSyms[i]);
   }
 
+  if (!MMI->getLandingPads().empty()) {
+    CurrentFnBegin = createTempSymbol("eh_func_begin", getFunctionNumber());
+
+    if (MAI->useAssignmentForEHBegin()) {
+      MCSymbol *CurPos = OutContext.CreateTempSymbol();
+      OutStreamer.EmitLabel(CurPos);
+      OutStreamer.EmitAssignment(CurrentFnBegin,
+                                 MCSymbolRefExpr::Create(CurPos, OutContext));
+    } else {
+      OutStreamer.EmitLabel(CurrentFnBegin);
+    }
+  }
+
   // Emit pre-function debug and/or EH information.
   for (const HandlerInfo &HI : Handlers) {
     NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
@@ -867,6 +882,12 @@ void AsmPrinter::EmitFunctionBody() {
   // Emit target-specific gunk after the function body.
   EmitFunctionBodyEnd();
 
+  if (!MMI->getLandingPads().empty()) {
+    // Create a symbol for the end of function.
+    CurrentFnEnd = createTempSymbol("eh_func_end", getFunctionNumber());
+    OutStreamer.EmitLabel(CurrentFnEnd);
+  }
+
   // If the target wants a .size directive for the size of the function, emit
   // it.
   if (MAI->hasDotTypeDotSizeDirective()) {
@@ -2273,6 +2294,9 @@ MCSymbol *AsmPrinter::GetTempSymbol(const Twine &Name) const {
                                       Name);
 }
 
+MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name, unsigned ID) const {
+  return OutContext.createTempSymbol(Name + Twine(ID));
+}
 
 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
   return MMI->getAddrLabelSymbol(BA->getBasicBlock());
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
index f45b24c17f7..128ec82995b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -113,18 +113,6 @@ void DwarfCFIException::beginFunction(const MachineFunction *MF) {
       TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
   Asm->OutStreamer.EmitCFIPersonality(Sym, PerEncoding);
 
-  MCSymbol *EHBegin =
-      Asm->GetTempSymbol("eh_func_begin", Asm->getFunctionNumber());
-  if (Asm->MAI->useAssignmentForEHBegin()) {
-    MCContext &Ctx = Asm->OutContext;
-    MCSymbol *CurPos = Ctx.CreateTempSymbol();
-    Asm->OutStreamer.EmitLabel(CurPos);
-    Asm->OutStreamer.EmitAssignment(EHBegin,
-                                    MCSymbolRefExpr::Create(CurPos, Ctx));
-  } else {
-    Asm->OutStreamer.EmitLabel(EHBegin);
-  }
-
   // Provide LSDA information.
   if (!shouldEmitLSDA)
     return;
@@ -145,9 +133,6 @@ void DwarfCFIException::endFunction(const MachineFunction *) {
   if (!shouldEmitPersonality)
     return;
 
-  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
-                                                Asm->getFunctionNumber()));
-
   // Map all labels and get rid of any dead landing pads.
   MMI->TidyLandingPads();
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
index 4841814afff..e4084db0535 100644
--- a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
@@ -552,16 +552,14 @@ void EHStreamer::emitExceptionTable() {
          I = CallSites.begin(), E = CallSites.end(); I != E; ++I) {
       const CallSiteEntry &S = *I;
 
-      MCSymbol *EHFuncBeginSym =
-        Asm->GetTempSymbol("eh_func_begin", Asm->getFunctionNumber());
+      MCSymbol *EHFuncBeginSym = Asm->getFunctionBegin();
 
       MCSymbol *BeginLabel = S.BeginLabel;
       if (!BeginLabel)
         BeginLabel = EHFuncBeginSym;
       MCSymbol *EndLabel = S.EndLabel;
       if (!EndLabel)
-        EndLabel = Asm->GetTempSymbol("eh_func_end", Asm->getFunctionNumber());
-
+        EndLabel = Asm->getFunctionEnd();
 
       // Offset of the call site relative to the previous call site, counted in
       // number of 16-byte bundles. The first call site is counted relative to
diff --git a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
index 2b03877faec..356a35135d1 100644
--- a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
@@ -80,9 +80,6 @@ void Win64Exception::beginFunction(const MachineFunction *MF) {
   const MCSymbol *PersHandlerSym =
       TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
   Asm->OutStreamer.EmitWinEHHandler(PersHandlerSym, true, true);
-
-  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
-                                                Asm->getFunctionNumber()));
 }
 
 /// endFunction - Gather and emit post-function exception information.
@@ -91,9 +88,6 @@ void Win64Exception::endFunction(const MachineFunction *) {
   if (!shouldEmitPersonality && !shouldEmitMoves)
     return;
 
-  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
-                                                Asm->getFunctionNumber()));
-
   // Map all labels and get rid of any dead landing pads.
   MMI->TidyLandingPads();
 
@@ -170,10 +164,8 @@ void Win64Exception::emitCSpecificHandlerTable() {
   SmallVector<CallSiteEntry, 64> CallSites;
   computeCallSiteTable(CallSites, LandingPads, FirstActions);
 
-  MCSymbol *EHFuncBeginSym =
-      Asm->GetTempSymbol("eh_func_begin", Asm->getFunctionNumber());
-  MCSymbol *EHFuncEndSym =
-      Asm->GetTempSymbol("eh_func_end", Asm->getFunctionNumber());
+  MCSymbol *EHFuncBeginSym = Asm->getFunctionBegin();
+  MCSymbol *EHFuncEndSym = Asm->getFunctionEnd();
 
   // Emit the number of table entries.
   unsigned NumEntries = 0;