lldb/source/Plugins/Process/Utility/RegisterFlagsDetector_arm64.h

   1 //===-- RegisterFlagsDetector_arm64.h ---------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERFLAGSDETECTOR_ARM64_H
  10 #define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERFLAGSDETECTOR_ARM64_H
  11
  12 #include "lldb/Target/RegisterFlags.h"
  13 #include "llvm/ADT/StringRef.h"
  14 #include <functional>
  15
  16 namespace lldb_private {
  17
  18 struct RegisterInfo;
  19
  20 /// This class manages the storage and detection of register field information.
  21 /// The same register may have different fields on different CPUs. This class
  22 /// abstracts out the field detection process so we can use it on live processes
  23 /// and core files.
  24 ///
  25 /// The way to use this class is:
  26 /// * Make an instance somewhere that will last as long as the debug session
  27 ///   (because your final register info will point to this instance).
  28 /// * Read hardware capabilities from a core note, binary, prctl, etc.
  29 /// * Pass those to DetectFields.
  30 /// * Call UpdateRegisterInfo with your RegisterInfo to add pointers
  31 ///   to the detected fields for all registers listed in this class.
  32 ///
  33 /// This must be done in that order, and you should ensure that if multiple
  34 /// threads will reference the information, a mutex is used to make sure only
  35 /// one calls DetectFields.
  36 class Arm64RegisterFlagsDetector {
  37 public:
  38   /// For the registers listed in this class, detect which fields are
  39   /// present. Must be called before UpdateRegisterInfos.
  40   /// If called more than once, fields will be redetected each time from
  41   /// scratch. If the target would not have this register at all, the list of
  42   /// fields will be left empty.
  43   void DetectFields(uint64_t hwcap, uint64_t hwcap2);
  44
  45   /// Add the field information of any registers named in this class,
  46   /// to the relevant RegisterInfo instances. Note that this will be done
  47   /// with a pointer to the instance of this class that you call this on, so
  48   /// the lifetime of that instance must be at least that of the register info.
  49   void UpdateRegisterInfo(const RegisterInfo *reg_info, uint32_t num_regs);
  50
  51   /// Returns true if field detection has been run at least once.
  52   bool HasDetected() const { return m_has_detected; }
  53
  54 private:
  55   using Fields = std::vector<RegisterFlags::Field>;
  56   using DetectorFn = std::function<Fields(uint64_t, uint64_t)>;
  57
  58   static Fields DetectCPSRFields(uint64_t hwcap, uint64_t hwcap2);
  59   static Fields DetectFPSRFields(uint64_t hwcap, uint64_t hwcap2);
  60   static Fields DetectFPCRFields(uint64_t hwcap, uint64_t hwcap2);
  61   static Fields DetectMTECtrlFields(uint64_t hwcap, uint64_t hwcap2);
  62   static Fields DetectSVCRFields(uint64_t hwcap, uint64_t hwcap2);
  63   static Fields DetectFPMRFields(uint64_t hwcap, uint64_t hwcap2);
  64
  65   struct RegisterEntry {
  66     RegisterEntry(llvm::StringRef name, unsigned size, DetectorFn detector)
  67         : m_name(name), m_flags(std::string(name) + "_flags", size, {}),
  68           m_detector(detector) {}
  69
  70     llvm::StringRef m_name;
  71     RegisterFlags m_flags;
  72     DetectorFn m_detector;
  73   } m_registers[6] = {
  74       RegisterEntry("cpsr", 4, DetectCPSRFields),
  75       RegisterEntry("fpsr", 4, DetectFPSRFields),
  76       RegisterEntry("fpcr", 4, DetectFPCRFields),
  77       RegisterEntry("mte_ctrl", 8, DetectMTECtrlFields),
  78       RegisterEntry("svcr", 8, DetectSVCRFields),
  79       RegisterEntry("fpmr", 8, DetectFPMRFields),
  80   };
  81
  82   // Becomes true once field detection has been run for all registers.
  83   bool m_has_detected = false;
  84 };
  85
  86 } // namespace lldb_private
  87
  88 #endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_REGISTERFLAGSDETECTOR_ARM64_H