[AArch64] - Return address signing dwarf support

- Reapply changes intially introduced in r343089
- The archtecture info is no longer loaded whenever a DWARFContext is created
- The runtimes libraries (santiziers) make use of the dwarf context classes but
  do not intialise the target info
- The architecture of the object can be obtained without loading the target info
- Adding a method to the dwarf context to get this information and multiplex the
  string printing later on

Differential Revision: https://reviews.llvm.org/D55774

llvm-svn: 349472

1 files changed, 20 insertions, 1 deletions

diff --git a/llvm/lib/BinaryFormat/Dwarf.cpp b/llvm/lib/BinaryFormat/Dwarf.cpp
index 5984de73ae6..fe8ce2bd7aa 100644
--- a/llvm/lib/BinaryFormat/Dwarf.cpp
+++ b/llvm/lib/BinaryFormat/Dwarf.cpp
@@ -13,6 +13,7 @@
 
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Support/ErrorHandling.h"
 
 using namespace llvm;
@@ -455,14 +456,32 @@ StringRef llvm::dwarf::RangeListEncodingString(unsigned Encoding) {
   }
 }
 
-StringRef llvm::dwarf::CallFrameString(unsigned Encoding) {
+StringRef llvm::dwarf::CallFrameString(unsigned Encoding,
+    Triple::ArchType Arch) {
+  assert(Arch != llvm::Triple::ArchType::UnknownArch);
+#define SELECT_AARCH64 (Arch == llvm::Triple::aarch64_be || Arch == llvm::Triple::aarch64)
+#define SELECT_MIPS64 Arch == llvm::Triple::mips64
+#define SELECT_SPARC (Arch == llvm::Triple::sparc || Arch == llvm::Triple::sparcv9)
+#define SELECT_X86 (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64)
+#define HANDLE_DW_CFA(ID, NAME)
+#define HANDLE_DW_CFA_PRED(ID, NAME, PRED) \
+  if (ID == Encoding && PRED) \
+    return "DW_CFA_" #NAME;
+#include "llvm/BinaryFormat/Dwarf.def"
+
   switch (Encoding) {
   default:
     return StringRef();
+#define HANDLE_DW_CFA_PRED(ID, NAME, PRED)
 #define HANDLE_DW_CFA(ID, NAME)                                                \
   case DW_CFA_##NAME:                                                          \
     return "DW_CFA_" #NAME;
 #include "llvm/BinaryFormat/Dwarf.def"
+
+#undef SELECT_X86
+#undef SELECT_SPARC
+#undef SELECT_MIPS64
+#undef SELECT_AARCH64
   }
 }