1 //===-- ABIMacOSX_i386.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_ABIMACOSX_I386_H 10 #define LLDB_SOURCE_PLUGINS_ABI_X86_ABIMACOSX_I386_H 11 12 #include "Plugins/ABI/X86/ABIX86_i386.h" 13 #include "lldb/Core/Value.h" 14 #include "lldb/lldb-private.h" 15 16 class ABIMacOSX_i386 : public ABIX86_i386 { 17 public: 18 ~ABIMacOSX_i386() override = default; 19 20 size_t GetRedZoneSize() const override; 21 22 bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp, 23 lldb::addr_t func_addr, lldb::addr_t return_addr, 24 llvm::ArrayRef<lldb::addr_t> args) const override; 25 26 bool GetArgumentValues(lldb_private::Thread &thread, 27 lldb_private::ValueList &values) const override; 28 29 lldb_private::Status 30 SetReturnValueObject(lldb::StackFrameSP &frame_sp, 31 lldb::ValueObjectSP &new_value) override; 32 33 bool 34 CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override; 35 36 bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override; 37 38 bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override; 39 40 // The Darwin i386 ABI requires that stack frames be 16 byte aligned. 41 // When there is a trap handler on the stack, e.g. _sigtramp in userland 42 // code, we've seen that the stack pointer is often not aligned properly 43 // before the handler is invoked. This means that lldb will stop the unwind 44 // early -- before the function which caused the trap. 45 // 46 // To work around this, we relax that alignment to be just word-size 47 // (4-bytes). 48 // Allowing the trap handlers for user space would be easy (_sigtramp) but 49 // in other environments there can be a large number of different functions 50 // involved in async traps. 51 // 52 // If we were to enforce 16-byte alignment, we also need to relax to 4-byte 53 // alignment for non-darwin i386 targets. 54 bool CallFrameAddressIsValid(lldb::addr_t cfa) override { 55 // Make sure the stack call frame addresses are 4 byte aligned 56 if (cfa & (4ull - 1ull)) 57 return false; // Not 4 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 // Just make sure the address is a valid 32 bit address. 65 return pc <= UINT32_MAX; 66 } 67 68 // Static Functions 69 70 static void Initialize(); 71 72 static void Terminate(); 73 74 static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch); 75 76 // PluginInterface protocol 77 78 static llvm::StringRef GetPluginNameStatic() { return "abi.macosx-i386"; } 79 80 llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); } 81 82 protected: 83 lldb::ValueObjectSP 84 GetReturnValueObjectImpl(lldb_private::Thread &thread, 85 lldb_private::CompilerType &ast_type) const override; 86 87 bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info); 88 89 std::string GetMCName(std::string name) override { 90 MapRegisterName(name, "stmm", "st"); 91 return name; 92 } 93 94 private: 95 using ABIX86_i386::ABIX86_i386; // Call CreateInstance instead. 96 }; 97 98 #endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABIMACOSX_I386_H 99