[PATCH] [CodeGen] Force emission of personality directive if explicitly specified

[Keno Fischer]

Hi majnemer,

Before this change, personality directives were not emitted if there was no landing pad left in the function
(of course until recently this also meant that we couldn't know what the personality actually was).
Allow this now and add a test case for it.

REPOSITORY
  rL LLVM

http://reviews.llvm.org/D10884

Files:
  include/llvm/CodeGen/MachineModuleInfo.h
  lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
  lib/CodeGen/AsmPrinter/EHStreamer.cpp
  lib/CodeGen/MachineModuleInfo.cpp

Index: include/llvm/CodeGen/MachineModuleInfo.h
===================================================================
--- include/llvm/CodeGen/MachineModuleInfo.h
+++ include/llvm/CodeGen/MachineModuleInfo.h
@@ -320,6 +320,7 @@
   /// information.
   void addPersonality(MachineBasicBlock *LandingPad,
                       const Function *Personality);
+  void addPersonality(const Function *Personality);
 
   void addWinEHState(MachineBasicBlock *LandingPad, int State);
 
Index: lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
+++ lib/CodeGen/AsmPrinter/DwarfCFIException.cpp
@@ -92,6 +92,7 @@
 
   // If any landing pads survive, we need an EH table.
   bool hasLandingPads = !MMI->getLandingPads().empty();
+  bool forceEmitPersonality = MF->getFunction()->hasPersonalityFn();
 
   // See if we need frame move info.
   AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
@@ -104,10 +105,13 @@
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   unsigned PerEncoding = TLOF.getPersonalityEncoding();
-  const Function *Per = MMI->getPersonality();
+  const Function *Per = MF->getFunction()->hasPersonalityFn() ?
+    dyn_cast<Function>(MF->getFunction()->getPersonalityFn()) : nullptr;
+  if (!Per)
+    Per = MMI->getPersonality();
 
-  shouldEmitPersonality = hasLandingPads &&
-    PerEncoding != dwarf::DW_EH_PE_omit && Per;
+  shouldEmitPersonality = (forceEmitPersonality || (hasLandingPads &&
+    PerEncoding != dwarf::DW_EH_PE_omit)) && Per;
 
   unsigned LSDAEncoding = TLOF.getLSDAEncoding();
   shouldEmitLSDA = shouldEmitPersonality &&
@@ -123,6 +127,11 @@
   if (!shouldEmitPersonality)
     return;
 
+  // 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);
+
   const MCSymbol *Sym =
       TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
   Asm->OutStreamer->EmitCFIPersonality(Sym, PerEncoding);
Index: lib/CodeGen/AsmPrinter/EHStreamer.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/EHStreamer.cpp
+++ lib/CodeGen/AsmPrinter/EHStreamer.cpp
@@ -309,7 +309,7 @@
   // If some instruction between the previous try-range and the end of the
   // function may throw, create a call-site entry with no landing pad for the
   // region following the try-range.
-  if (SawPotentiallyThrowing && !IsSJLJ) {
+  if (SawPotentiallyThrowing && !IsSJLJ && LastLabel != nullptr) {
     CallSiteEntry Site = { LastLabel, nullptr, nullptr, 0 };
     CallSites.push_back(Site);
   }
Index: lib/CodeGen/MachineModuleInfo.cpp
===================================================================
--- lib/CodeGen/MachineModuleInfo.cpp
+++ lib/CodeGen/MachineModuleInfo.cpp
@@ -320,7 +320,10 @@
                                        const Function *Personality) {
   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
   LP.Personality = Personality;
+  addPersonality(Personality);
+}
 
+void MachineModuleInfo::addPersonality(const Function *Personality) {
   for (unsigned i = 0; i < Personalities.size(); ++i)
     if (Personalities[i] == Personality)
       return;

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