Implement DW_CFA_LLVM_* for Heterogeneous Debugging

Add support in MC/MIR for writing/parsing, and DebugInfo.

This is part of the Extensions for Heterogeneous Debugging defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html

Specifically the CFI instructions implemented here are defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html#cfa-definition-instructions

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D76877

4 files changed, 57 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 2da51f8..f9800a3 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -315,6 +315,8 @@ public:
   void emitCFIDefCfa(int64_t Register, int64_t Offset) override;
   void emitCFIDefCfaOffset(int64_t Offset) override;
   void emitCFIDefCfaRegister(int64_t Register) override;
+  void emitCFILLVMDefAspaceCfa(int64_t Register, int64_t Offset,
+                               int64_t AddressSpace) override;
   void emitCFIOffset(int64_t Register, int64_t Offset) override;
   void emitCFIPersonality(const MCSymbol *Sym, unsigned Encoding) override;
   void emitCFILsda(const MCSymbol *Sym, unsigned Encoding) override;
@@ -1810,6 +1812,16 @@ void MCAsmStreamer::emitCFIDefCfaOffset(int64_t Offset) {
   EmitEOL();
 }
 
+void MCAsmStreamer::emitCFILLVMDefAspaceCfa(int64_t Register, int64_t Offset,
+                                            int64_t AddressSpace) {
+  MCStreamer::emitCFILLVMDefAspaceCfa(Register, Offset, AddressSpace);
+  OS << "\t.cfi_llvm_def_aspace_cfa ";
+  EmitRegisterName(Register);
+  OS << ", " << Offset;
+  OS << ", " << AddressSpace;
+  EmitEOL();
+}
+
 static void PrintCFIEscape(llvm::formatted_raw_ostream &OS, StringRef Values) {
   OS << "\t.cfi_escape ";
   if (!Values.empty()) {
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 51e3ac9..217584e 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -1405,6 +1405,19 @@ void FrameEmitterImpl::emitCFIInstruction(const MCCFIInstruction &Instr) {
 
     return;
   }
+  // TODO: Implement `_sf` variants if/when they need to be emitted.
+  case MCCFIInstruction::OpLLVMDefAspaceCfa: {
+    unsigned Reg = Instr.getRegister();
+    if (!IsEH)
+      Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
+    Streamer.emitIntValue(dwarf::DW_CFA_LLVM_def_aspace_cfa, 1);
+    Streamer.emitULEB128IntValue(Reg);
+    CFAOffset = Instr.getOffset();
+    Streamer.emitULEB128IntValue(CFAOffset);
+    Streamer.emitULEB128IntValue(Instr.getAddressSpace());
+
+    return;
+  }
   case MCCFIInstruction::OpOffset:
   case MCCFIInstruction::OpRelOffset: {
     const bool IsRelative =
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 2383a02..8e4752c 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -499,6 +499,7 @@ private:
     DK_CFI_DEF_CFA_OFFSET,
     DK_CFI_ADJUST_CFA_OFFSET,
     DK_CFI_DEF_CFA_REGISTER,
+    DK_CFI_LLVM_DEF_ASPACE_CFA,
     DK_CFI_OFFSET,
     DK_CFI_REL_OFFSET,
     DK_CFI_PERSONALITY,
@@ -600,6 +601,7 @@ private:
   bool parseDirectiveCFIDefCfa(SMLoc DirectiveLoc);
   bool parseDirectiveCFIAdjustCfaOffset();
   bool parseDirectiveCFIDefCfaRegister(SMLoc DirectiveLoc);
+  bool parseDirectiveCFILLVMDefAspaceCfa(SMLoc DirectiveLoc);
   bool parseDirectiveCFIOffset(SMLoc DirectiveLoc);
   bool parseDirectiveCFIRelOffset(SMLoc DirectiveLoc);
   bool parseDirectiveCFIPersonalityOrLsda(bool IsPersonality);
@@ -2186,6 +2188,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info,
       return parseDirectiveCFIAdjustCfaOffset();
     case DK_CFI_DEF_CFA_REGISTER:
       return parseDirectiveCFIDefCfaRegister(IDLoc);
+    case DK_CFI_LLVM_DEF_ASPACE_CFA:
+      return parseDirectiveCFILLVMDefAspaceCfa(IDLoc);
     case DK_CFI_OFFSET:
       return parseDirectiveCFIOffset(IDLoc);
     case DK_CFI_REL_OFFSET:
@@ -4260,6 +4264,19 @@ bool AsmParser::parseDirectiveCFIDefCfaRegister(SMLoc DirectiveLoc) {
   return false;
 }
 
+/// parseDirectiveCFILLVMDefAspaceCfa
+/// ::= .cfi_llvm_def_aspace_cfa register, offset, address_space
+bool AsmParser::parseDirectiveCFILLVMDefAspaceCfa(SMLoc DirectiveLoc) {
+  int64_t Register = 0, Offset = 0, AddressSpace = 0;
+  if (parseRegisterOrRegisterNumber(Register, DirectiveLoc) || parseComma() ||
+      parseAbsoluteExpression(Offset) || parseComma() ||
+      parseAbsoluteExpression(AddressSpace) || parseEOL())
+    return true;
+
+  getStreamer().emitCFILLVMDefAspaceCfa(Register, Offset, AddressSpace);
+  return false;
+}
+
 /// parseDirectiveCFIOffset
 /// ::= .cfi_offset register, offset
 bool AsmParser::parseDirectiveCFIOffset(SMLoc DirectiveLoc) {
@@ -5497,6 +5514,7 @@ void AsmParser::initializeDirectiveKindMap() {
   DirectiveKindMap[".cfi_def_cfa_offset"] = DK_CFI_DEF_CFA_OFFSET;
   DirectiveKindMap[".cfi_adjust_cfa_offset"] = DK_CFI_ADJUST_CFA_OFFSET;
   DirectiveKindMap[".cfi_def_cfa_register"] = DK_CFI_DEF_CFA_REGISTER;
+  DirectiveKindMap[".cfi_llvm_def_aspace_cfa"] = DK_CFI_LLVM_DEF_ASPACE_CFA;
   DirectiveKindMap[".cfi_offset"] = DK_CFI_OFFSET;
   DirectiveKindMap[".cfi_rel_offset"] = DK_CFI_REL_OFFSET;
   DirectiveKindMap[".cfi_personality"] = DK_CFI_PERSONALITY;
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 5d06240..2a1998f 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -444,7 +444,8 @@ void MCStreamer::emitCFIStartProc(bool IsSimple, SMLoc Loc) {
   if (MAI) {
     for (const MCCFIInstruction& Inst : MAI->getInitialFrameState()) {
       if (Inst.getOperation() == MCCFIInstruction::OpDefCfa ||
-          Inst.getOperation() == MCCFIInstruction::OpDefCfaRegister) {
+          Inst.getOperation() == MCCFIInstruction::OpDefCfaRegister ||
+          Inst.getOperation() == MCCFIInstruction::OpLLVMDefAspaceCfa) {
         Frame.CurrentCfaRegister = Inst.getRegister();
       }
     }
@@ -517,6 +518,18 @@ void MCStreamer::emitCFIDefCfaRegister(int64_t Register) {
   CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
 }
 
+void MCStreamer::emitCFILLVMDefAspaceCfa(int64_t Register, int64_t Offset,
+                                         int64_t AddressSpace) {
+  MCSymbol *Label = emitCFILabel();
+  MCCFIInstruction Instruction = MCCFIInstruction::createLLVMDefAspaceCfa(
+      Label, Register, Offset, AddressSpace);
+  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
+  if (!CurFrame)
+    return;
+  CurFrame->Instructions.push_back(Instruction);
+  CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
+}
+
 void MCStreamer::emitCFIOffset(int64_t Register, int64_t Offset) {
   MCSymbol *Label = emitCFILabel();
   MCCFIInstruction Instruction =