From 379ff50dcc7ccf977379aee68fa9d10f69065d23 Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Sun, 9 Aug 2026 18:31:49 +0800
Subject: [MC] Implement RV64GC assembly emission

---
 backend/include/rcc/CodeGen/AsmPrinter.h           |  57 ++++++
 backend/include/rcc/CodeGen/CompilationUnit.h      |  13 ++
 backend/include/rcc/CodeGen/GlobalObject.h         | 196 +++++++++++++++++++++
 backend/include/rcc/CodeGen/MachineMCContext.h     |  68 +++++++
 backend/include/rcc/CodeGen/TargetMCInstLowering.h |  69 ++++++++
 5 files changed, 403 insertions(+)
 create mode 100644 backend/include/rcc/CodeGen/AsmPrinter.h
 create mode 100644 backend/include/rcc/CodeGen/GlobalObject.h
 create mode 100644 backend/include/rcc/CodeGen/MachineMCContext.h
 create mode 100644 backend/include/rcc/CodeGen/TargetMCInstLowering.h

(limited to 'backend/include/rcc/CodeGen')

diff --git a/backend/include/rcc/CodeGen/AsmPrinter.h b/backend/include/rcc/CodeGen/AsmPrinter.h
new file mode 100644
index 0000000..82bad7d
--- /dev/null
+++ b/backend/include/rcc/CodeGen/AsmPrinter.h
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_ASMPRINTER_H
+#define RCC_CODEGEN_ASMPRINTER_H
+
+#include "rcc/Support/Error.h"
+
+namespace rcc {
+
+class CompilationUnit;
+class MachineFunction;
+class MachineMCContext;
+class TargetDescription;
+class TargetMCInstLowering;
+
+namespace mc {
+class MCStreamer;
+} // namespace mc
+
+struct AsmPrinterOptions final {
+  bool EmitFunctionDirectives = true;
+  bool EmitCFI = true;
+  bool EmitBlockLabels = true;
+  bool EmitInstructionSymbols = true;
+  bool VerifyInput = true;
+};
+
+class AsmPrinter final {
+public:
+  AsmPrinter(const TargetDescription &Target, const TargetMCInstLowering &Lowering,
+             MachineMCContext &Context, mc::MCStreamer &Streamer,
+             AsmPrinterOptions Options = {}) noexcept
+      : Target(&Target), Lowering(&Lowering), Context(&Context), Streamer(&Streamer),
+        Options(Options) {}
+
+  [[nodiscard]] Expected<void> emitCompilationUnit(const CompilationUnit &Unit);
+  [[nodiscard]] Expected<void> emitFunction(const MachineFunction &Function);
+
+private:
+  [[nodiscard]] Expected<void> verifyFunction(const MachineFunction &Function) const;
+  [[nodiscard]] Expected<void> emitGlobalObjects(const CompilationUnit &Unit);
+  [[nodiscard]] Expected<void> emitFunctionBody(const MachineFunction &Function);
+  [[nodiscard]] Expected<void> emitConstantPool(const MachineFunction &Function);
+  [[nodiscard]] Expected<void> emitJumpTables(const MachineFunction &Function);
+
+  const TargetDescription *Target;
+  const TargetMCInstLowering *Lowering;
+  MachineMCContext *Context;
+  mc::MCStreamer *Streamer;
+  AsmPrinterOptions Options;
+  bool UnitEmissionStarted = false;
+  bool UnitEmissionFinished = false;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_ASMPRINTER_H
diff --git a/backend/include/rcc/CodeGen/CompilationUnit.h b/backend/include/rcc/CodeGen/CompilationUnit.h
index d798438..14fd86f 100644
--- a/backend/include/rcc/CodeGen/CompilationUnit.h
+++ b/backend/include/rcc/CodeGen/CompilationUnit.h
@@ -3,6 +3,7 @@
 #ifndef RCC_CODEGEN_COMPILATIONUNIT_H
 #define RCC_CODEGEN_COMPILATIONUNIT_H
 
+#include "rcc/CodeGen/GlobalObject.h"
 #include "rcc/CodeGen/StableID.h"
 #include "rcc/Support/Error.h"
 
@@ -28,6 +29,7 @@ public:
   ~CompilationUnit();
 
   [[nodiscard]] Expected<MachineFunction *> createMachineFunction(std::string Name);
+  [[nodiscard]] Expected<GlobalObjectDesc *> addGlobalObject(GlobalObjectDesc Object);
 
   [[nodiscard]] std::size_t functionCount() const noexcept {
     return Functions.size();
@@ -40,6 +42,15 @@ public:
   [[nodiscard]] MachineFunction *function(MachineFunctionStableID ID) noexcept;
   [[nodiscard]] const MachineFunction *function(MachineFunctionStableID ID) const noexcept;
 
+  [[nodiscard]] std::size_t globalObjectCount() const noexcept {
+    return GlobalObjects.size();
+  }
+
+  [[nodiscard]] GlobalObjectDesc *globalObjectAt(std::size_t Index) noexcept;
+  [[nodiscard]] const GlobalObjectDesc *globalObjectAt(std::size_t Index) const noexcept;
+  [[nodiscard]] GlobalObjectDesc *globalObject(std::string_view Name) noexcept;
+  [[nodiscard]] const GlobalObjectDesc *globalObject(std::string_view Name) const noexcept;
+
   [[nodiscard]] Expected<void> verify() const;
 
 private:
@@ -53,6 +64,8 @@ private:
 
   std::vector<std::unique_ptr<MachineFunction>> Functions;
   std::unordered_map<std::string, std::size_t, StringHash, std::equal_to<>> FunctionNameToIndex;
+  std::vector<std::unique_ptr<GlobalObjectDesc>> GlobalObjects;
+  std::unordered_map<std::string, std::size_t, StringHash, std::equal_to<>> GlobalNameToIndex;
   StableIDGenerator<MachineFunctionStableID> FunctionIDGenerator;
 };
 
diff --git a/backend/include/rcc/CodeGen/GlobalObject.h b/backend/include/rcc/CodeGen/GlobalObject.h
new file mode 100644
index 0000000..49f1f42
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalObject.h
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALOBJECT_H
+#define RCC_CODEGEN_GLOBALOBJECT_H
+
+#include "rcc/CodeGen/GenericConstant.h"
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/CodeGen/TargetConstant.h"
+#include "rcc/Support/Error.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include <string>
+#include <utility>
+#include <variant>
+#include <vector>
+
+namespace rcc {
+
+class GlobalInitializer;
+using GlobalInitializerRef = std::shared_ptr<const GlobalInitializer>;
+
+struct GlobalZeroFill final {
+  std::uint64_t Size = 0;
+};
+
+struct GlobalRepeatedInitializer final {
+  std::uint64_t Count = 0;
+  GlobalInitializerRef Value;
+};
+
+struct GlobalAggregateInitializer final {
+  std::vector<GlobalInitializerRef> Elements;
+};
+
+struct GlobalSymbolAddress final {
+  std::string Symbol;
+  std::int64_t Addend = 0;
+  std::uint8_t Size = 8;
+  std::uint32_t TargetFlags = 0;
+};
+
+struct GlobalSymbolDifference final {
+  std::string Minuend;
+  std::string Subtrahend;
+  std::int64_t Addend = 0;
+  std::uint8_t Size = 8;
+};
+
+struct GlobalAlignmentPadding final {
+  std::uint64_t Size = 0;
+  std::uint8_t Fill = 0;
+};
+
+struct GlobalUndefinedStorage final {
+  std::uint64_t Size = 0;
+};
+
+class GlobalInitializer final {
+public:
+  enum class Kind : std::uint8_t {
+    Invalid,
+    Integer,
+    Floating,
+    Bytes,
+    ZeroFill,
+    Repeated,
+    Aggregate,
+    SymbolAddress,
+    SymbolDifference,
+    Target,
+    AlignmentPadding,
+    UndefinedStorage,
+  };
+
+  GlobalInitializer() = default;
+  GlobalInitializer(const GlobalInitializer &) = delete;
+  GlobalInitializer &operator=(const GlobalInitializer &) = delete;
+  GlobalInitializer(GlobalInitializer &&) noexcept = default;
+  GlobalInitializer &operator=(GlobalInitializer &&) noexcept = default;
+  ~GlobalInitializer() = default;
+
+  [[nodiscard]] static GlobalInitializer integer(IntegerImmediate Value);
+  [[nodiscard]] static GlobalInitializer floating(FloatingPointBits Value);
+  [[nodiscard]] static Expected<GlobalInitializer> bytes(std::vector<std::byte> Value);
+  [[nodiscard]] static Expected<GlobalInitializer> zeroFill(std::uint64_t Size);
+  [[nodiscard]] static Expected<GlobalInitializer> repeated(std::uint64_t Count,
+                                                            GlobalInitializer Value);
+  [[nodiscard]] static Expected<GlobalInitializer>
+  aggregate(std::vector<GlobalInitializer> Elements);
+  [[nodiscard]] static Expected<GlobalInitializer> symbolAddress(GlobalSymbolAddress Value);
+  [[nodiscard]] static Expected<GlobalInitializer> symbolDifference(GlobalSymbolDifference Value);
+  [[nodiscard]] static Expected<GlobalInitializer> target(TargetConstant Value);
+  [[nodiscard]] static Expected<GlobalInitializer> alignmentPadding(std::uint64_t Size,
+                                                                    std::uint8_t Fill = 0);
+  [[nodiscard]] static Expected<GlobalInitializer> undefinedStorage(std::uint64_t Size);
+
+  [[nodiscard]] Kind kind() const noexcept;
+
+  template <typename ValueT> [[nodiscard]] const ValueT *getIf() const noexcept {
+    return std::get_if<ValueT>(&Storage);
+  }
+
+  [[nodiscard]] Expected<void> verify(std::size_t MaximumDepth = 1024) const;
+  [[nodiscard]] Expected<std::uint64_t> storageSize(std::size_t MaximumDepth = 1024) const;
+
+private:
+  using StorageT =
+      std::variant<std::monostate, IntegerImmediate, FloatingPointBits, std::vector<std::byte>,
+                   GlobalZeroFill, GlobalRepeatedInitializer, GlobalAggregateInitializer,
+                   GlobalSymbolAddress, GlobalSymbolDifference, TargetConstant,
+                   GlobalAlignmentPadding, GlobalUndefinedStorage>;
+
+  explicit GlobalInitializer(StorageT Storage) : Storage(std::move(Storage)) {}
+
+  StorageT Storage;
+};
+
+enum class GlobalLinkage : std::uint8_t {
+  External,
+  AvailableExternally,
+  LinkOnceAny,
+  LinkOnceODR,
+  WeakAny,
+  WeakODR,
+  Appending,
+  Internal,
+  Private,
+  ExternalWeak,
+  Common,
+  Count,
+};
+
+enum class GlobalVisibility : std::uint8_t {
+  Default,
+  Hidden,
+  Protected,
+  Count,
+};
+
+enum class GlobalTLSModel : std::uint8_t {
+  None,
+  GeneralDynamic,
+  LocalDynamic,
+  InitialExec,
+  LocalExec,
+  Count,
+};
+
+enum class GlobalUnnamedAddress : std::uint8_t {
+  None,
+  Local,
+  Global,
+  Count,
+};
+
+struct GlobalObjectDesc final {
+  std::string Symbol;
+  GenericConstantType ObjectType;
+  GlobalLinkage Linkage = GlobalLinkage::External;
+  GlobalVisibility Visibility = GlobalVisibility::Default;
+  bool DSOLocal = false;
+  std::optional<std::string> Section;
+  Alignment Align;
+  std::uint64_t Size = 0;
+  std::uint32_t AddressSpace = 0;
+  GlobalTLSModel TLSModel = GlobalTLSModel::None;
+  bool ExternallyInitialized = false;
+  std::optional<std::string> COMDAT;
+  bool IsConstant = false;
+  GlobalUnnamedAddress UnnamedAddress = GlobalUnnamedAddress::None;
+  std::optional<GlobalInitializer> Initializer;
+  std::vector<std::string> DebugExpressions;
+  std::optional<OriginID> StableOrigin;
+  std::uint64_t TargetFlags = 0;
+  std::vector<std::pair<std::string, std::string>> TargetAttributes;
+
+  GlobalObjectDesc() = default;
+  GlobalObjectDesc(const GlobalObjectDesc &) = delete;
+  GlobalObjectDesc &operator=(const GlobalObjectDesc &) = delete;
+  GlobalObjectDesc(GlobalObjectDesc &&) noexcept = default;
+  GlobalObjectDesc &operator=(GlobalObjectDesc &&) noexcept = default;
+  ~GlobalObjectDesc() = default;
+
+  [[nodiscard]] bool isDeclaration() const noexcept {
+    return !Initializer.has_value() && Linkage != GlobalLinkage::Common;
+  }
+
+  [[nodiscard]] Expected<void> verify() const;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALOBJECT_H
diff --git a/backend/include/rcc/CodeGen/MachineMCContext.h b/backend/include/rcc/CodeGen/MachineMCContext.h
new file mode 100644
index 0000000..2464dc5
--- /dev/null
+++ b/backend/include/rcc/CodeGen/MachineMCContext.h
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_MACHINEMCCONTEXT_H
+#define RCC_CODEGEN_MACHINEMCCONTEXT_H
+
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/MC/MCContext.h"
+#include "rcc/MC/MCSymbol.h"
+#include "rcc/Support/Error.h"
+
+#include <string>
+#include <string_view>
+#include <unordered_map>
+
+namespace rcc {
+
+class CompilationUnit;
+struct GlobalObjectDesc;
+class MachineBasicBlock;
+class MachineFunction;
+
+class MachineMCContext final {
+public:
+  explicit MachineMCContext(mc::MCContext &Context) noexcept : Context(&Context) {}
+
+  [[nodiscard]] Expected<void> initialize(const CompilationUnit &Unit);
+  [[nodiscard]] Expected<void> initializeFunction(const MachineFunction &Function);
+
+  [[nodiscard]] mc::MCSymbolRef functionSymbol(const MachineFunction &Function) const noexcept;
+  [[nodiscard]] mc::MCSymbolRef globalSymbol(const GlobalObjectDesc &Object) const noexcept;
+  [[nodiscard]] mc::MCSymbolRef blockSymbol(const MachineBasicBlock &Block) const noexcept;
+  [[nodiscard]] mc::MCSymbolRef constantPoolSymbol(const MachineFunction &Function,
+                                                   ConstantPoolIndex Index) const noexcept;
+  [[nodiscard]] mc::MCSymbolRef jumpTableSymbol(const MachineFunction &Function,
+                                                JumpTableIndex Index) const noexcept;
+
+  [[nodiscard]] Expected<mc::MCSymbolRef> symbol(std::string Name,
+                                                 mc::MCSymbolKind Kind = mc::MCSymbolKind::Generic);
+  [[nodiscard]] Expected<mc::MCSymbolRef> blockAddressSymbol(std::string_view FunctionName,
+                                                             std::string_view BlockName) const;
+
+  [[nodiscard]] mc::MCContext &context() const noexcept {
+    return *Context;
+  }
+
+private:
+  struct FunctionIndexKey final {
+    const MachineFunction *Function = nullptr;
+    std::uint32_t Index = 0;
+
+    friend bool operator==(FunctionIndexKey Left, FunctionIndexKey Right) noexcept = default;
+  };
+
+  struct FunctionIndexHash final {
+    [[nodiscard]] std::size_t operator()(FunctionIndexKey Key) const noexcept;
+  };
+
+  mc::MCContext *Context;
+  std::unordered_map<const MachineFunction *, mc::MCSymbolRef> FunctionSymbols;
+  std::unordered_map<const GlobalObjectDesc *, mc::MCSymbolRef> GlobalSymbols;
+  std::unordered_map<const MachineBasicBlock *, mc::MCSymbolRef> BlockSymbols;
+  std::unordered_map<FunctionIndexKey, mc::MCSymbolRef, FunctionIndexHash> ConstantPoolSymbols;
+  std::unordered_map<FunctionIndexKey, mc::MCSymbolRef, FunctionIndexHash> JumpTableSymbols;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_MACHINEMCCONTEXT_H
diff --git a/backend/include/rcc/CodeGen/TargetMCInstLowering.h b/backend/include/rcc/CodeGen/TargetMCInstLowering.h
new file mode 100644
index 0000000..875d2dd
--- /dev/null
+++ b/backend/include/rcc/CodeGen/TargetMCInstLowering.h
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_TARGETMCINSTLOWERING_H
+#define RCC_CODEGEN_TARGETMCINSTLOWERING_H
+
+#include "rcc/MC/MCInst.h"
+#include "rcc/MC/MCInstPrinter.h"
+#include "rcc/MC/MCSection.h"
+#include "rcc/MC/MCStreamer.h"
+#include "rcc/Support/Error.h"
+
+namespace rcc {
+
+class MachineConstantPoolEntry;
+class GlobalInitializer;
+struct GlobalObjectDesc;
+class MachineFunction;
+class MachineInstr;
+class MachineJumpTableEntry;
+class MachineMCContext;
+struct GenericConstantData;
+class TargetConstant;
+
+class TargetMCInstLowering {
+public:
+  virtual ~TargetMCInstLowering() = default;
+
+  [[nodiscard]] virtual const mc::MCInstPrinter &instructionPrinter() const noexcept = 0;
+
+  [[nodiscard]] virtual Expected<mc::MCInst> lowerInstruction(const MachineInstr &Instruction,
+                                                              MachineMCContext &Context) const = 0;
+
+  [[nodiscard]] virtual Expected<void> emitTerminalInstruction(const MachineInstr &Instruction,
+                                                               MachineMCContext &Context,
+                                                               mc::MCStreamer &Streamer) const;
+
+  [[nodiscard]] virtual Expected<mc::MCSectionDesc>
+  textSection(const MachineFunction &Function) const = 0;
+  [[nodiscard]] virtual Expected<mc::MCSectionDesc>
+  globalSection(const GlobalObjectDesc &Object, MachineMCContext &Context) const = 0;
+  [[nodiscard]] virtual Expected<mc::MCSectionDesc>
+  constantPoolSection(const MachineFunction &Function,
+                      const MachineConstantPoolEntry &Entry) const = 0;
+  [[nodiscard]] virtual Expected<mc::MCSectionDesc>
+  jumpTableSection(const MachineFunction &Function, const MachineJumpTableEntry &Entry) const = 0;
+
+  [[nodiscard]] virtual Expected<void> emitFileHeader(MachineMCContext &Context,
+                                                      mc::MCStreamer &Streamer) const;
+  [[nodiscard]] virtual Expected<void> emitFileTrailer(MachineMCContext &Context,
+                                                       mc::MCStreamer &Streamer) const;
+  [[nodiscard]] virtual Expected<void> emitGenericConstant(const GenericConstantData &Constant,
+                                                           std::uint64_t Size,
+                                                           MachineMCContext &Context,
+                                                           mc::MCStreamer &Streamer) const;
+  [[nodiscard]] virtual Expected<void> emitGlobalInitializer(const GlobalInitializer &Initializer,
+                                                             MachineMCContext &Context,
+                                                             mc::MCStreamer &Streamer) const;
+  [[nodiscard]] virtual Expected<void> emitTargetConstant(const TargetConstant &Constant,
+                                                          MachineMCContext &Context,
+                                                          mc::MCStreamer &Streamer) const;
+  [[nodiscard]] virtual Expected<void> emitTargetJumpTable(const MachineFunction &Function,
+                                                           const MachineJumpTableEntry &Entry,
+                                                           MachineMCContext &Context,
+                                                           mc::MCStreamer &Streamer) const;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_TARGETMCINSTLOWERING_H
-- 
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