Big change #1 for personality function references:

Eliminate the PersonalityPrefix/Suffix & NeedsIndirectEncoding
fields from MAI: they aren't part of the asm syntax, they are
related to the structure of the object file.

To replace their functionality, add a new 
TLOF::getSymbolForDwarfGlobalReference method which asks targets
to decide how to reference a global from EH in a pc-relative way.

The default implementation just returns the symbol.  The default
darwin implementation references the symbol through an indirect
$non_lazy_ptr stub.  The bizarro x86-64 darwin specialization
handles the weird "foo@GOTPCREL+4" hack.

DwarfException.cpp now uses this to emit the reference to the
symbol in the right way, and this also eliminates another 
horrible hack from DwarfException.cpp:

-    if (strcmp(MAI->getPersonalitySuffix(), "+4@GOTPCREL"))
-      O << "-" << MAI->getPCSymbol();



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81991 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86TargetObjectFile.cpp

@@ -0,0 +1,33 @@
+//===-- llvm/Target/X86/X86TargetObjectFile.cpp - X86 Object Info ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86TargetObjectFile.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Mangler.h"
+#include "llvm/MC/MCExpr.h"
+using namespace llvm;
+
+const MCExpr *X8664_MachoTargetObjectFile::
+getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
+                                 bool &IsIndirect, bool &IsPCRel) const {
+  
+  // On Darwin/X86-64, we can reference dwarf symbols with foo@GOTPCREL+4, which
+  // is an indirect pc-relative reference.
+  IsIndirect = true;
+  IsPCRel    = true;
+  
+  SmallString<128> Name;
+  Mang->getNameWithPrefix(Name, GV, false);
+  Name += "@GOTPCREL";
+  const MCExpr *Res =
+    MCSymbolRefExpr::Create(Name.str(), getContext());
+  const MCExpr *Four = MCConstantExpr::Create(4, getContext());
+  return MCBinaryExpr::CreateAdd(Res, Four, getContext());
+}
+