1 files changed, 275 insertions, 0 deletions
diff --git a/backend/lib/CodeGen/MachineCFIInfo.cpp b/backend/lib/CodeGen/MachineCFIInfo.cpp
new file mode 100644
index 0000000..db9f319
--- /dev/null
+++ b/backend/lib/CodeGen/MachineCFIInfo.cpp
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "rcc/CodeGen/MachineCFIInfo.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <limits>
+#include <string>
+#include <utility>
+
+namespace rcc {
+namespace {
+
+[[nodiscard]] Expected<void> verifyVectorRegisters(const MachineCFIVectorRegistersRule &Rule,
+                                                   ErrorCode Code) {
+  if (Rule.VectorRegisters.empty()) {
+    return makeUnexpected(Code, "CFI vector-register rule must contain at least one lane");
+  }
+  return {};
+}
+
+} // namespace
+
+MachineCFIInstruction MachineCFIInstruction::sameValue(DwarfRegisterNumber Register) {
+  return MachineCFIInstruction(MachineCFIOperation::SameValue, MachineCFIRegisterRule{Register});
+}
+
+MachineCFIInstruction MachineCFIInstruction::rememberState() {
+  return MachineCFIInstruction(MachineCFIOperation::RememberState, MachineCFINoOperands{});
+}
+
+MachineCFIInstruction MachineCFIInstruction::restoreState() {
+  return MachineCFIInstruction(MachineCFIOperation::RestoreState, MachineCFINoOperands{});
+}
+
+MachineCFIInstruction MachineCFIInstruction::offset(DwarfRegisterNumber Register,
+                                                    std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::Offset,
+                               MachineCFIRegisterOffsetRule{Register, Offset});
+}
+
+MachineCFIInstruction MachineCFIInstruction::llvmDefAddressSpaceCFA(DwarfRegisterNumber Register,
+                                                                    std::int64_t Offset,
+                                                                    std::uint32_t AddressSpace) {
+  return MachineCFIInstruction(MachineCFIOperation::LLVMDefAddressSpaceCFA,
+                               MachineCFIAddressSpaceCFARule{Register, Offset, AddressSpace});
+}
+
+MachineCFIInstruction MachineCFIInstruction::defCFARegister(DwarfRegisterNumber Register) {
+  return MachineCFIInstruction(MachineCFIOperation::DefCFARegister,
+                               MachineCFIRegisterRule{Register});
+}
+
+MachineCFIInstruction MachineCFIInstruction::defCFAOffset(std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::DefCFAOffset, MachineCFIOffsetRule{Offset});
+}
+
+MachineCFIInstruction MachineCFIInstruction::defCFA(DwarfRegisterNumber Register,
+                                                    std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::DefCFA,
+                               MachineCFIRegisterOffsetRule{Register, Offset});
+}
+
+MachineCFIInstruction MachineCFIInstruction::relativeOffset(DwarfRegisterNumber Register,
+                                                            std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::RelativeOffset,
+                               MachineCFIRegisterOffsetRule{Register, Offset});
+}
+
+MachineCFIInstruction MachineCFIInstruction::adjustCFAOffset(std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::AdjustCFAOffset, MachineCFIOffsetRule{Offset});
+}
+
+Expected<MachineCFIInstruction> MachineCFIInstruction::escape(std::vector<std::uint8_t> Bytes) {
+  if (Bytes.empty())
+    return makeUnexpected(ErrorCode::InvalidArgument, "CFI escape byte sequence cannot be empty");
+  return MachineCFIInstruction(MachineCFIOperation::Escape, MachineCFIEscapeRule{std::move(Bytes)});
+}
+
+MachineCFIInstruction MachineCFIInstruction::restore(DwarfRegisterNumber Register) {
+  return MachineCFIInstruction(MachineCFIOperation::Restore, MachineCFIRegisterRule{Register});
+}
+
+MachineCFIInstruction MachineCFIInstruction::undefined(DwarfRegisterNumber Register) {
+  return MachineCFIInstruction(MachineCFIOperation::Undefined, MachineCFIRegisterRule{Register});
+}
+
+MachineCFIInstruction MachineCFIInstruction::registerRule(DwarfRegisterNumber Register,
+                                                          DwarfRegisterNumber SourceRegister) {
+  return MachineCFIInstruction(MachineCFIOperation::Register,
+                               MachineCFIRegisterRegisterRule{Register, SourceRegister});
+}
+
+MachineCFIInstruction MachineCFIInstruction::windowSave() {
+  return MachineCFIInstruction(MachineCFIOperation::WindowSave, MachineCFINoOperands{});
+}
+
+MachineCFIInstruction MachineCFIInstruction::negateReturnAddressState() {
+  return MachineCFIInstruction(MachineCFIOperation::NegateReturnAddressState,
+                               MachineCFINoOperands{});
+}
+
+MachineCFIInstruction MachineCFIInstruction::negateReturnAddressStateWithPC() {
+  return MachineCFIInstruction(MachineCFIOperation::NegateReturnAddressStateWithPC,
+                               MachineCFINoOperands{});
+}
+
+MachineCFIInstruction MachineCFIInstruction::gnuArgsSize(std::int64_t Size) {
+  return MachineCFIInstruction(MachineCFIOperation::GNUArgsSize, MachineCFIOffsetRule{Size});
+}
+
+Expected<MachineCFIInstruction> MachineCFIInstruction::label(std::string Symbol) {
+  if (Symbol.empty())
+    return makeUnexpected(ErrorCode::InvalidArgument, "CFI label symbol cannot be empty");
+  return MachineCFIInstruction(MachineCFIOperation::Label, MachineCFILabelRule{std::move(Symbol)});
+}
+
+MachineCFIInstruction MachineCFIInstruction::valueOffset(DwarfRegisterNumber Register,
+                                                         std::int64_t Offset) {
+  return MachineCFIInstruction(MachineCFIOperation::ValueOffset,
+                               MachineCFIRegisterOffsetRule{Register, Offset});
+}
+
+MachineCFIInstruction MachineCFIInstruction::llvmRegisterPair(MachineCFIRegisterPairRule Rule) {
+  return MachineCFIInstruction(MachineCFIOperation::LLVMRegisterPair, Rule);
+}
+
+Expected<MachineCFIInstruction>
+MachineCFIInstruction::llvmVectorRegisters(MachineCFIVectorRegistersRule Rule) {
+  auto Verification = verifyVectorRegisters(Rule, ErrorCode::InvalidArgument);
+  if (!Verification)
+    return std::unexpected(Verification.error());
+  return MachineCFIInstruction(MachineCFIOperation::LLVMVectorRegisters, std::move(Rule));
+}
+
+MachineCFIInstruction MachineCFIInstruction::llvmVectorOffset(MachineCFIVectorOffsetRule Rule) {
+  return MachineCFIInstruction(MachineCFIOperation::LLVMVectorOffset, Rule);
+}
+
+MachineCFIInstruction
+MachineCFIInstruction::llvmVectorRegisterMask(MachineCFIVectorRegisterMaskRule Rule) {
+  return MachineCFIInstruction(MachineCFIOperation::LLVMVectorRegisterMask, Rule);
+}
+
+Expected<void> MachineCFIInstruction::verify() const {
+  switch (Operation) {
+  case MachineCFIOperation::SameValue:
+  case MachineCFIOperation::DefCFARegister:
+  case MachineCFIOperation::Restore:
+  case MachineCFIOperation::Undefined:
+    if (getIf<MachineCFIRegisterRule>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::RememberState:
+  case MachineCFIOperation::RestoreState:
+  case MachineCFIOperation::WindowSave:
+  case MachineCFIOperation::NegateReturnAddressState:
+  case MachineCFIOperation::NegateReturnAddressStateWithPC:
+    if (getIf<MachineCFINoOperands>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::Offset:
+  case MachineCFIOperation::DefCFA:
+  case MachineCFIOperation::RelativeOffset:
+  case MachineCFIOperation::ValueOffset:
+    if (getIf<MachineCFIRegisterOffsetRule>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::LLVMDefAddressSpaceCFA:
+    if (getIf<MachineCFIAddressSpaceCFARule>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::DefCFAOffset:
+  case MachineCFIOperation::AdjustCFAOffset:
+  case MachineCFIOperation::GNUArgsSize:
+    if (getIf<MachineCFIOffsetRule>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::Escape: {
+    const auto *Rule = getIf<MachineCFIEscapeRule>();
+    if (Rule == nullptr)
+      break;
+    if (Rule->Bytes.empty()) {
+      return makeUnexpected(ErrorCode::VerificationError,
+                            "CFI escape byte sequence cannot be empty");
+    }
+    return {};
+  }
+  case MachineCFIOperation::Register:
+    if (getIf<MachineCFIRegisterRegisterRule>() == nullptr)
+      break;
+    return {};
+  case MachineCFIOperation::Label: {
+    const auto *Rule = getIf<MachineCFILabelRule>();
+    if (Rule == nullptr)
+      break;
+    if (Rule->Symbol.empty())
+      return makeUnexpected(ErrorCode::VerificationError, "CFI label symbol cannot be empty");
+    return {};
+  }
+  case MachineCFIOperation::LLVMRegisterPair: {
+    const auto *Rule = getIf<MachineCFIRegisterPairRule>();
+    if (Rule == nullptr)
+      break;
+    return {};
+  }
+  case MachineCFIOperation::LLVMVectorRegisters: {
+    const auto *Rule = getIf<MachineCFIVectorRegistersRule>();
+    if (Rule == nullptr)
+      break;
+    return verifyVectorRegisters(*Rule, ErrorCode::VerificationError);
+  }
+  case MachineCFIOperation::LLVMVectorOffset: {
+    const auto *Rule = getIf<MachineCFIVectorOffsetRule>();
+    if (Rule == nullptr)
+      break;
+    return {};
+  }
+  case MachineCFIOperation::LLVMVectorRegisterMask: {
+    const auto *Rule = getIf<MachineCFIVectorRegisterMaskRule>();
+    if (Rule == nullptr)
+      break;
+    return {};
+  }
+  case MachineCFIOperation::Count:
+    break;
+  }
+  return makeUnexpected(ErrorCode::VerificationError,
+                        "CFI instruction operation and payload do not match");
+}
+
+Expected<CFIInstructionIndex> MachineCFIInfo::addInstruction(MachineCFIInstruction Instruction) {
+  auto Verification = Instruction.verify();
+  if (!Verification)
+    return std::unexpected(Verification.error());
+  if (Instructions.size() > std::numeric_limits<std::uint32_t>::max()) {
+    return makeUnexpected(ErrorCode::Unsupported, "CFI instruction index space is exhausted");
+  }
+
+  const auto Index =
+      CFIInstructionIndex::fromValue(static_cast<std::uint32_t>(Instructions.size()));
+  Instructions.push_back(std::move(Instruction));
+  return Index;
+}
+
+const MachineCFIInstruction *MachineCFIInfo::instruction(CFIInstructionIndex Index) const noexcept {
+  if (Index.value() >= Instructions.size())
+    return nullptr;
+  return &Instructions[Index.value()];
+}
+
+Expected<void> MachineCFIInfo::verify() const {
+  for (const MachineCFIInstruction &Instruction : Instructions) {
+    auto Verification = Instruction.verify();
+    if (!Verification)
+      return std::unexpected(Verification.error());
+  }
+  return {};
+}
+
+Expected<MachineCFIInfo> MachineCFIInfo::clone() const {
+  auto Verification = verify();
+  if (!Verification)
+    return std::unexpected(Verification.error());
+
+  MachineCFIInfo Result;
+  for (const MachineCFIInstruction &Instruction : Instructions) {
+    auto Index = Result.addInstruction(Instruction);
+    if (!Index)
+      return std::unexpected(Index.error());
+  }
+  return Result;
+}
+
+} // namespace rcc