Fix ARM EHABI when function has landingpad and nounwind.

If the function has the landingpad instruction, then the
handlerdata should be emitted even if the function has
nouwnind attribute.  Otherwise, following code will not
work:

    void test1() noexcept {
      try {
        throw_exception();
      } catch (...) {
        log_unexpected_exception();
      }
    }

Since the cantunwind was incorrectly emitted and the
LSDA is not available.

llvm-svn: 208791

1 files changed, 7 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
index 97b288f1947..1cb0159d10f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp
@@ -59,9 +59,8 @@ void ARMException::endModule() {
 void ARMException::beginFunction(const MachineFunction *MF) {
   if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
     getTargetStreamer().emitFnStart();
-  if (Asm->MF->getFunction()->needsUnwindTableEntry())
-    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
-                                                  Asm->getFunctionNumber()));
+  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 &&
@@ -78,16 +77,16 @@ void ARMException::endFunction(const MachineFunction *) {
   if (shouldEmitCFI)
     Asm->OutStreamer.EmitCFIEndProc();
 
+  // Map all labels and get rid of any dead landing pads.
+  MMI->TidyLandingPads();
+
   ARMTargetStreamer &ATS = getTargetStreamer();
-  if (!Asm->MF->getFunction()->needsUnwindTableEntry())
+  if (!Asm->MF->getFunction()->needsUnwindTableEntry() &&
+      MMI->getLandingPads().empty())
     ATS.emitCantUnwind();
   else {
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
                                                   Asm->getFunctionNumber()));
-
-    // Map all labels and get rid of any dead landing pads.
-    MMI->TidyLandingPads();
-
     if (!MMI->getLandingPads().empty()) {
       // Emit references to personality.
       if (const Function * Personality =