Re-land r235154-r235156 under the existing -sehprepare flag

Keep the old SEH fan-in lowering on by default for now, since projects
rely on it.  This will make it easy to test this change with a simple
flag flip.

llvm-svn: 235399

1 files changed, 30 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
index 8c90bed2b5a..2737a5323d6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/Win64Exception.cpp
@@ -212,9 +212,14 @@ void Win64Exception::emitCSpecificHandlerTable() {
       if (isCatchEHSelector(Selector))
         ++NumEntries;
     }
+    NumEntries += CSE.LPad->SEHHandlers.size();
   }
   Asm->OutStreamer.EmitIntValue(NumEntries, 4);
 
+  // If there are no actions, we don't need to iterate again.
+  if (NumEntries == 0)
+    return;
+
   // Emit the four-label records for each call site entry. The table has to be
   // sorted in layout order, and the call sites should already be sorted.
   for (const CallSiteEntry &CSE : CallSites) {
@@ -240,6 +245,31 @@ void Win64Exception::emitCSpecificHandlerTable() {
       End = createImageRel32(EHFuncEndSym);
     }
 
+    // Emit an entry for each action.
+    for (SEHHandler Handler : LPad->SEHHandlers) {
+      Asm->OutStreamer.EmitValue(Begin, 4);
+      Asm->OutStreamer.EmitValue(End, 4);
+
+      // Emit the filter or finally function pointer, if present. Otherwise,
+      // emit '1' to indicate a catch-all.
+      const Function *F = Handler.FilterOrFinally;
+      if (F)
+        Asm->OutStreamer.EmitValue(createImageRel32(Asm->getSymbol(F)), 4);
+      else
+        Asm->OutStreamer.EmitIntValue(1, 4);
+
+      // Emit the recovery address, if present. Otherwise, this must be a
+      // finally.
+      const BlockAddress *BA = Handler.RecoverBA;
+      if (BA)
+        Asm->OutStreamer.EmitValue(
+            createImageRel32(Asm->GetBlockAddressSymbol(BA)), 4);
+      else
+        Asm->OutStreamer.EmitIntValue(0, 4);
+    }
+    if (!LPad->SEHHandlers.empty())
+      continue;
+
     // These aren't really type info globals, they are actually pointers to
     // filter functions ordered by selector. The zero selector is used for
     // cleanups, so slot zero corresponds to selector 1.