1 //===-- Architecture.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_CORE_ARCHITECTURE_H 10 #define LLDB_CORE_ARCHITECTURE_H 11 12 #include "lldb/Core/PluginInterface.h" 13 14 namespace lldb_private { 15 16 class Architecture : public PluginInterface { 17 public: 18 Architecture() = default; 19 ~Architecture() override = default; 20 21 /// This is currently intended to handle cases where a 22 /// program stops at an instruction that won't get executed and it 23 /// allows the stop reason, like "breakpoint hit", to be replaced 24 /// with a different stop reason like "no stop reason". 25 /// 26 /// This is specifically used for ARM in Thumb code when we stop in 27 /// an IT instruction (if/then/else) where the instruction won't get 28 /// executed and therefore it wouldn't be correct to show the program 29 /// stopped at the current PC. The code is generic and applies to all 30 /// ARM CPUs. 31 virtual void OverrideStopInfo(Thread &thread) const = 0; 32 33 /// This method is used to get the number of bytes that should be 34 /// skipped, from function start address, to reach the first 35 /// instruction after the prologue. If overrode, it must return 36 /// non-zero only if the current address matches one of the known 37 /// function entry points. 38 /// 39 /// This method is called only if the standard platform-independent 40 /// code fails to get the number of bytes to skip, giving the plugin 41 /// a chance to try to find the missing info. 42 /// 43 /// This is specifically used for PPC64, where functions may have 44 /// more than one entry point, global and local, so both should 45 /// be compared with current address, in order to find out the 46 /// number of bytes that should be skipped, in case we are stopped 47 /// at either function entry point. 48 virtual size_t GetBytesToSkip(Symbol &func, const Address &curr_addr) const { 49 return 0; 50 } 51 52 /// Adjust function breakpoint address, if needed. In some cases, 53 /// the function start address is not the right place to set the 54 /// breakpoint, specially in functions with multiple entry points. 55 /// 56 /// This is specifically used for PPC64, for functions that have 57 /// both a global and a local entry point. In this case, the 58 /// breakpoint is adjusted to the first function address reached 59 /// by both entry points. 60 virtual void AdjustBreakpointAddress(const Symbol &func, 61 Address &addr) const {} 62 63 64 /// Get \a load_addr as a callable code load address for this target 65 /// 66 /// Take \a load_addr and potentially add any address bits that are 67 /// needed to make the address callable. For ARM this can set bit 68 /// zero (if it already isn't) if \a load_addr is a thumb function. 69 /// If \a addr_class is set to AddressClass::eInvalid, then the address 70 /// adjustment will always happen. If it is set to an address class 71 /// that doesn't have code in it, LLDB_INVALID_ADDRESS will be 72 /// returned. 73 virtual lldb::addr_t GetCallableLoadAddress( 74 lldb::addr_t addr, AddressClass addr_class = AddressClass::eInvalid) const { 75 return addr; 76 } 77 78 /// Get \a load_addr as an opcode for this target. 79 /// 80 /// Take \a load_addr and potentially strip any address bits that are 81 /// needed to make the address point to an opcode. For ARM this can 82 /// clear bit zero (if it already isn't) if \a load_addr is a 83 /// thumb function and load_addr is in code. 84 /// If \a addr_class is set to AddressClass::eInvalid, then the address 85 /// adjustment will always happen. If it is set to an address class 86 /// that doesn't have code in it, LLDB_INVALID_ADDRESS will be 87 /// returned. 88 89 virtual lldb::addr_t GetOpcodeLoadAddress( 90 lldb::addr_t addr, AddressClass addr_class = AddressClass::eInvalid) const { 91 return addr; 92 } 93 94 // Get load_addr as breakable load address for this target. Take a addr and 95 // check if for any reason there is a better address than this to put a 96 // breakpoint on. If there is then return that address. For MIPS, if 97 // instruction at addr is a delay slot instruction then this method will find 98 // the address of its previous instruction and return that address. 99 virtual lldb::addr_t GetBreakableLoadAddress(lldb::addr_t addr, 100 Target &target) const { 101 return addr; 102 } 103 104 private: 105 Architecture(const Architecture &) = delete; 106 void operator=(const Architecture &) = delete; 107 }; 108 109 } // namespace lldb_private 110 111 #endif // LLDB_CORE_ARCHITECTURE_H 112