lldb/source/Plugins/ABI/X86/ABISysV_x86_64.h

   1 //===-- ABISysV_x86_64.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_ABI_X86_ABISYSV_X86_64_H
  10 #define LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
  11
  12 #include "Plugins/ABI/X86/ABIX86_64.h"
  13
  14 class ABISysV_x86_64 : public ABIX86_64 {
  15 public:
  16   ~ABISysV_x86_64() override = default;
  17
  18   size_t GetRedZoneSize() const override;
  19
  20   bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
  21                           lldb::addr_t functionAddress,
  22                           lldb::addr_t returnAddress,
  23                           llvm::ArrayRef<lldb::addr_t> args) const override;
  24
  25   bool GetArgumentValues(lldb_private::Thread &thread,
  26                          lldb_private::ValueList &values) const override;
  27
  28   lldb_private::Status
  29   SetReturnValueObject(lldb::StackFrameSP &frame_sp,
  30                        lldb::ValueObjectSP &new_value) override;
  31
  32   lldb::ValueObjectSP
  33   GetReturnValueObjectImpl(lldb_private::Thread &thread,
  34                            lldb_private::CompilerType &type) const override;
  35
  36   bool
  37   CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
  38
  39   bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
  40
  41   bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;
  42
  43   // The SysV x86_64 ABI requires that stack frames be 16 byte aligned.
  44   // When there is a trap handler on the stack, e.g. _sigtramp in userland
  45   // code, we've seen that the stack pointer is often not aligned properly
  46   // before the handler is invoked.  This means that lldb will stop the unwind
  47   // early -- before the function which caused the trap.
  48   //
  49   // To work around this, we relax that alignment to be just word-size
  50   // (8-bytes).
  51   // Allowing the trap handlers for user space would be easy (_sigtramp) but
  52   // in other environments there can be a large number of different functions
  53   // involved in async traps.
  54   bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
  55     // Make sure the stack call frame addresses are 8 byte aligned
  56     if (cfa & (8ull - 1ull))
  57       return false; // Not 8 byte aligned
  58     if (cfa == 0)
  59       return false; // Zero is not a valid stack address
  60     return true;
  61   }
  62
  63   bool CodeAddressIsValid(lldb::addr_t pc) override {
  64     // We have a 64 bit address space, so anything is valid as opcodes
  65     // aren't fixed width...
  66     return true;
  67   }
  68
  69   bool GetPointerReturnRegister(const char *&name) override;
  70
  71   // Static Functions
  72
  73   static void Initialize();
  74
  75   static void Terminate();
  76
  77   static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
  78
  79   static llvm::StringRef GetPluginNameStatic() { return "sysv-x86_64"; }
  80
  81   // PluginInterface protocol
  82   llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
  83
  84 protected:
  85   void CreateRegisterMapIfNeeded();
  86
  87   lldb::ValueObjectSP
  88   GetReturnValueObjectSimple(lldb_private::Thread &thread,
  89                              lldb_private::CompilerType &ast_type) const;
  90
  91   bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
  92   uint32_t GetGenericNum(llvm::StringRef reg) override;
  93
  94 private:
  95   using ABIX86_64::ABIX86_64; // Call CreateInstance instead.
  96 };
  97
  98 #endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H