[Lldb-commits] [lldb] [LLDB][Process/Utility] Introduce NativeRegisterContextDBReg class (PR #118043)

[David Spickett via lldb-commits]

================
@@ -9,79 +9,16 @@
 #ifndef lldb_NativeRegisterContextDBReg_arm64_h
 #define lldb_NativeRegisterContextDBReg_arm64_h
 
-#include "Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h"
-
-#include <array>
+#include "Plugins/Process/Utility/NativeRegisterContextDBReg.h"
 
 namespace lldb_private {
 
-class NativeRegisterContextDBReg_arm64
-    : public virtual NativeRegisterContextRegisterInfo {
-public:
-  uint32_t NumSupportedHardwareBreakpoints() override;
-
-  uint32_t SetHardwareBreakpoint(lldb::addr_t addr, size_t size) override;
-
-  bool ClearHardwareBreakpoint(uint32_t hw_idx) override;
-
-  Status ClearAllHardwareBreakpoints() override;
-
-  Status GetHardwareBreakHitIndex(uint32_t &bp_index,
-                                  lldb::addr_t trap_addr) override;
-
-  bool BreakpointIsEnabled(uint32_t bp_index);
-
-  uint32_t NumSupportedHardwareWatchpoints() override;
-
-  uint32_t SetHardwareWatchpoint(lldb::addr_t addr, size_t size,
-                                 uint32_t watch_flags) override;
-
-  bool ClearHardwareWatchpoint(uint32_t hw_index) override;
-
-  Status ClearAllHardwareWatchpoints() override;
-
-  Status GetWatchpointHitIndex(uint32_t &wp_index,
-                               lldb::addr_t trap_addr) override;
-
-  lldb::addr_t GetWatchpointHitAddress(uint32_t wp_index) override;
-
-  lldb::addr_t GetWatchpointAddress(uint32_t wp_index) override;
-
-  uint32_t GetWatchpointSize(uint32_t wp_index);
-
-  bool WatchpointIsEnabled(uint32_t wp_index);
-
-  // Debug register type select
-  enum DREGType { eDREGTypeWATCH = 0, eDREGTypeBREAK };
-
-protected:
-  /// Debug register info for hardware breakpoints and watchpoints management.
-  /// Watchpoints: For a user requested size 4 at addr 0x1004, where BAS
-  /// watchpoints are at doubleword (8-byte) alignment.
-  ///   \a real_addr is 0x1004
-  ///   \a address is 0x1000
-  ///   size is 8
-  ///   If a one-byte write to 0x1006 is the most recent watchpoint trap,
-  ///   \a hit_addr is 0x1006
-  struct DREG {
-    lldb::addr_t address;  // Breakpoint/watchpoint address value.
-    lldb::addr_t hit_addr; // Address at which last watchpoint trigger exception
-                           // occurred.
-    lldb::addr_t real_addr; // Address value that should cause target to stop.
-    uint32_t control;       // Breakpoint/watchpoint control value.
-  };
-
-  std::array<struct DREG, 16> m_hbp_regs; // hardware breakpoints
-  std::array<struct DREG, 16> m_hwp_regs; // hardware watchpoints
+class NativeRegisterContextDBReg_arm64 : public NativeRegisterContextDBReg {
+  uint32_t GetWatchpointSize(uint32_t wp_index) override;
 
-  uint32_t m_max_hbp_supported;
-  uint32_t m_max_hwp_supported;
+  bool ValidateWatchpoint(size_t size, lldb::addr_t &addr) override;
----------------
DavidSpickett wrote:

If we want to prevent this sort of mistake it could be:
```
struct WatchpointDetails {
  size_t size;
  lldb::addr_t addr;
}
std::optional<WatchpointDetails> AdjustWatchpoint(const WatchPointDetails &details);
```
This is at least clearer that:
* This can fail (empty optional)
* New values are returned not assigned by reference

https://github.com/llvm/llvm-project/pull/118043