From b8fb9248e77e492c630ca135d1bfd58b74f9752a Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Mon, 24 Aug 2026 19:01:47 +0800
Subject: [CodeGen] Implement CFI instruction insertion

---
 backend/include/rcc/CodeGen/CFIInstrInserter.h    | 28 +++++++++++++++++++++++
 backend/include/rcc/CodeGen/TargetFrameLowering.h |  7 ++++++
 2 files changed, 35 insertions(+)
 create mode 100644 backend/include/rcc/CodeGen/CFIInstrInserter.h

(limited to 'backend/include/rcc')

diff --git a/backend/include/rcc/CodeGen/CFIInstrInserter.h b/backend/include/rcc/CodeGen/CFIInstrInserter.h
new file mode 100644
index 0000000..c6504fc
--- /dev/null
+++ b/backend/include/rcc/CodeGen/CFIInstrInserter.h
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_CFIINSTRINSERTER_H
+#define RCC_CODEGEN_CFIINSTRINSERTER_H
+
+#include "rcc/CodeGen/MachinePassManager.h"
+
+namespace rcc {
+
+class TargetFrameLowering;
+
+class CFIInstrInserterPass final : public MachineFunctionPass {
+public:
+  explicit CFIInstrInserterPass(const TargetFrameLowering &FrameLowering) noexcept
+      : FrameLowering(&FrameLowering) {}
+
+  [[nodiscard]] const MachinePassContract &contract() const noexcept override;
+  [[nodiscard]] Expected<MachinePassResult> run(MachineFunction &Function,
+                                                const TargetDescription &Target,
+                                                MachineFunctionAnalysisManager &Analyses) override;
+
+private:
+  const TargetFrameLowering *FrameLowering = nullptr;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_CFIINSTRINSERTER_H
diff --git a/backend/include/rcc/CodeGen/TargetFrameLowering.h b/backend/include/rcc/CodeGen/TargetFrameLowering.h
index 705a548..e3f0f37 100644
--- a/backend/include/rcc/CodeGen/TargetFrameLowering.h
+++ b/backend/include/rcc/CodeGen/TargetFrameLowering.h
@@ -31,6 +31,13 @@ class TargetFrameLowering {
 public:
   virtual ~TargetFrameLowering() = default;
 
+  [[nodiscard]] virtual PhysicalRegister
+  initialCFARegister(const MachineFunction &Function,
+                     const TargetDescription &Target) const noexcept = 0;
+  [[nodiscard]] virtual std::int64_t initialCFAOffset(const MachineFunction &) const noexcept {
+    return 0;
+  }
+
   [[nodiscard]] virtual Expected<void> prepareFrame(MachineFunction &Function,
                                                     const TargetDescription &Target,
                                                     FrameLoweringOptions Options = {}) const = 0;
-- 
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