[WinEH] Emit the LSDA even if no lpads remain but outlining occurred

The outlined funclets call intrinsics which reference labels from the
LSDA. This situation can easily arise in small functions with a single
cleanup at -O0, where Clang marks a definition as nounwind, and then
WinEHPrepare "discovers" that the landingpad is dead by accident and
deletes it.

We now need to ask the LLVM IR Function for it's personality directly,
rather than going through MachineModuleInfo.

Fixes PR23892.

llvm-svn: 242063

1 files changed, 14 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index 55f97e6214b..7ef2832d41a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -70,7 +70,9 @@ void WinException::beginFunction(const MachineFunction *MF) {
 
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   unsigned PerEncoding = TLOF.getPersonalityEncoding();
-  const Function *Per = MMI->getPersonality();
+  const Function *Per = nullptr;
+  if (F->hasPersonalityFn())
+    Per = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
 
   shouldEmitPersonality = hasLandingPads &&
     PerEncoding != dwarf::DW_EH_PE_omit && Per;
@@ -79,10 +81,12 @@ void WinException::beginFunction(const MachineFunction *MF) {
   shouldEmitLSDA = shouldEmitPersonality &&
     LSDAEncoding != dwarf::DW_EH_PE_omit;
 
-  // If we're not using CFI, we don't want the CFI or the personality. Emit the
-  // LSDA if this is the parent function.
+  // If we're not using CFI, we don't want the CFI or the personality. If
+  // WinEHPrepare outlined something, we should emit the LSDA.
   if (!Asm->MAI->usesWindowsCFI()) {
-    shouldEmitLSDA = (hasLandingPads && F == ParentF);
+    bool HasOutlinedChildren =
+        F->hasFnAttribute("wineh-parent") && F == ParentF;
+    shouldEmitLSDA = HasOutlinedChildren;
     shouldEmitPersonality = false;
     return;
   }
@@ -121,7 +125,10 @@ void WinException::endFunction(const MachineFunction *MF) {
   if (!shouldEmitPersonality && !shouldEmitMoves && !shouldEmitLSDA)
     return;
 
-  EHPersonality Per = MMI->getPersonalityType();
+  const Function *F = MF->getFunction();
+  EHPersonality Per = EHPersonality::Unknown;
+  if (F->hasPersonalityFn())
+    Per = classifyEHPersonality(F->getPersonalityFn());
 
   // Get rid of any dead landing pads if we're not using a Windows EH scheme. In
   // Windows EH schemes, the landing pad is not actually reachable. It only
@@ -582,7 +589,8 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
   OS.EmitValueToAlignment(4);
   OS.EmitLabel(LSDALabel);
 
-  const Function *Per = MMI->getPersonality();
+  const Function *Per =
+      dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
   StringRef PerName = Per->getName();
   int BaseState = -1;
   if (PerName == "_except_handler4") {