[WinCOFF] Add support for the .safeseh directive

.safeseh adds an entry to the .sxdata section to register all the
appropriate functions which may handle an exception.  This entry is not
a relocation to the symbol but instead the symbol table index of the
function.

llvm-svn: 238641

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/lib/MC/WinCOFFStreamer.cpp b/llvm/lib/MC/WinCOFFStreamer.cpp
index 72c18788068..abbe4164958 100644
--- a/llvm/lib/MC/WinCOFFStreamer.cpp
+++ b/llvm/lib/MC/WinCOFFStreamer.cpp
@@ -158,6 +158,21 @@ void MCWinCOFFStreamer::EndCOFFSymbolDef() {
   CurSymbol = nullptr;
 }
 
+void MCWinCOFFStreamer::EmitCOFFSafeSEH(MCSymbol const *Symbol) {
+  if (Symbol->getFlags() & COFF::SF_SafeSEH)
+    return;
+
+  MCSection *SXData = getContext().getObjectFileInfo()->getSXDataSection();
+  getAssembler().registerSection(*SXData);
+  if (SXData->getAlignment() < 4)
+    SXData->setAlignment(4);
+
+  new MCSafeSEHFragment(Symbol, SXData);
+
+  getAssembler().registerSymbol(*Symbol);
+  Symbol->modifyFlags(COFF::SF_SafeSEH, COFF::SF_SafeSEH);
+}
+
 void MCWinCOFFStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
   MCDataFragment *DF = getOrCreateDataFragment();
   const MCSymbolRefExpr *SRE = MCSymbolRefExpr::create(Symbol, getContext());