[WinEH] Emit EH tables for __CxxFrameHandler3 on 32-bit x86

Small (really small!) C++ exception handling examples work on 32-bit x86
now.

This change disables the use of .seh_* directives in WinException when
CFI is not in use. It also uses absolute symbol references in the tables
instead of imagerel32 relocations.

Also fixes a cache invalidation bug in MMI personality classification.

llvm-svn: 238575

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 71d4b06..03ef7ed 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -391,11 +391,17 @@ void MCStreamer::EmitCFIWindowSave() {
 }
 
 void MCStreamer::EnsureValidWinFrameInfo() {
+  const MCAsmInfo *MAI = Context.getAsmInfo();
+  if (!MAI->usesWindowsCFI())
+    report_fatal_error(".seh_* directives are not supported on this target");
   if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End)
     report_fatal_error("No open Win64 EH frame function!");
 }
 
 void MCStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
+  const MCAsmInfo *MAI = Context.getAsmInfo();
+  if (!MAI->usesWindowsCFI())
+    report_fatal_error(".seh_* directives are not supported on this target");
   if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
     report_fatal_error("Starting a function before ending the previous one!");