[AArch64] - Return address signing dwarf support

Functions that have signed return addresses need additional dwarf support:
- After signing the LR, and before authenticating it, the LR register is in a
  state the is unusable by a debugger or unwinder
- To account for this a new directive, .cfi_negate_ra_state, is added
- This directive says the signed state of the LR register has now changed,
  i.e. unsigned -> signed or signed -> unsigned
- This directive has the same CFA code as the SPARC directive GNU_window_save
  (0x2d), adding a macro to account for multiply defined codes
- This patch matches the gcc implementation of this support:
  https://patchwork.ozlabs.org/patch/800271/

Differential Revision: https://reviews.llvm.org/D50136

llvm-svn: 343089

2 files changed, 12 insertions, 9 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index a5c31a56fad..73fb90981ab 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -724,7 +724,7 @@ const DWARFDebugFrame *DWARFContext::getDebugFrame() {
   // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
   DWARFDataExtractor debugFrameData(DObj->getDebugFrameSection(),
                                     isLittleEndian(), DObj->getAddressSize());
-  DebugFrame.reset(new DWARFDebugFrame(false /* IsEH */));
+  DebugFrame.reset(new DWARFDebugFrame(Arch, false /* IsEH */));
   DebugFrame->parse(debugFrameData);
   return DebugFrame.get();
 }
@@ -735,7 +735,7 @@ const DWARFDebugFrame *DWARFContext::getEHFrame() {
 
   DWARFDataExtractor debugFrameData(DObj->getEHFrameSection(), isLittleEndian(),
                                     DObj->getAddressSize());
-  DebugFrame.reset(new DWARFDebugFrame(true /* IsEH */));
+  DebugFrame.reset(new DWARFDebugFrame(Arch, true /* IsEH */));
   DebugFrame->parse(debugFrameData);
   return DebugFrame.get();
 }
@@ -1581,9 +1581,11 @@ DWARFContext::create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
   return llvm::make_unique<DWARFContext>(std::move(DObj), "");
 }
 
-Error DWARFContext::loadRegisterInfo(const object::ObjectFile &Obj) {
+Error DWARFContext::loadArchitectureInfo(const object::ObjectFile &Obj) {
   // Detect the architecture from the object file. We usually don't need OS
   // info to lookup a target and create register info.
+  Arch = Triple::ArchType(Obj.getArch());
+
   Triple TT;
   TT.setArch(Triple::ArchType(Obj.getArch()));
   TT.setVendor(Triple::UnknownVendor);
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
index d725255fe4c..d85ab6bd8a5 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -225,7 +225,7 @@ void CFIProgram::printOperand(raw_ostream &OS, const MCRegisterInfo *MRI,
   switch (Type) {
   case OT_Unset: {
     OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to";
-    auto OpcodeName = CallFrameString(Opcode);
+    auto OpcodeName = CallFrameString(Opcode, Arch);
     if (!OpcodeName.empty())
       OS << " " << OpcodeName;
     else
@@ -279,7 +279,7 @@ void CFIProgram::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH,
     if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK)
       Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK;
     OS.indent(2 * IndentLevel);
-    OS << CallFrameString(Opcode) << ":";
+    OS << CallFrameString(Opcode, Arch) << ":";
     for (unsigned i = 0; i < Instr.Ops.size(); ++i)
       printOperand(OS, MRI, IsEH, Instr, i, Instr.Ops[i]);
     OS << '\n';
@@ -325,8 +325,9 @@ void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
   OS << "\n";
 }
 
-DWARFDebugFrame::DWARFDebugFrame(bool IsEH, uint64_t EHFrameAddress)
-    : IsEH(IsEH), EHFrameAddress(EHFrameAddress) {}
+DWARFDebugFrame::DWARFDebugFrame(Triple::ArchType Arch,
+    bool IsEH, uint64_t EHFrameAddress)
+    : Arch(Arch), IsEH(IsEH), EHFrameAddress(EHFrameAddress) {}
 
 DWARFDebugFrame::~DWARFDebugFrame() = default;
 
@@ -460,7 +461,7 @@ void DWARFDebugFrame::parse(DWARFDataExtractor Data) {
           StartOffset, Length, Version, AugmentationString, AddressSize,
           SegmentDescriptorSize, CodeAlignmentFactor, DataAlignmentFactor,
           ReturnAddressRegister, AugmentationData, FDEPointerEncoding,
-          LSDAPointerEncoding, Personality, PersonalityEncoding);
+          LSDAPointerEncoding, Personality, PersonalityEncoding, Arch);
       CIEs[StartOffset] = Cie.get();
       Entries.emplace_back(std::move(Cie));
     } else {
@@ -512,7 +513,7 @@ void DWARFDebugFrame::parse(DWARFDataExtractor Data) {
 
       Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
                                    InitialLocation, AddressRange,
-                                   Cie, LSDAAddress));
+                                   Cie, LSDAAddress, Arch));
     }
 
     if (Error E =