1 //===------------------- ABISysV_i386.h -------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 #ifndef liblldb_ABISysV_i386_h_
10 #define liblldb_ABISysV_i386_h_
12 #include "lldb/Target/ABI.h"
13 #include "lldb/lldb-private.h"
15 class ABISysV_i386 : public lldb_private::ABI {
17 ~ABISysV_i386() override = default;
19 size_t GetRedZoneSize() const override {
20 return 0; // There is no red zone for i386 Architecture
23 bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
24 lldb::addr_t functionAddress,
25 lldb::addr_t returnAddress,
26 llvm::ArrayRef<lldb::addr_t> args) const override;
28 bool GetArgumentValues(lldb_private::Thread &thread,
29 lldb_private::ValueList &values) const override;
32 SetReturnValueObject(lldb::StackFrameSP &frame_sp,
33 lldb::ValueObjectSP &new_value) override;
36 GetReturnValueObjectImpl(lldb_private::Thread &thread,
37 lldb_private::CompilerType &type) const override;
40 CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
42 bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
44 bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override {
45 return !RegisterIsCalleeSaved(reg_info);
48 // The SysV i386 ABI requires that stack frames be 16 byte aligned.
49 // When there is a trap handler on the stack, e.g. _sigtramp in userland
50 // code, we've seen that the stack pointer is often not aligned properly
51 // before the handler is invoked. This means that lldb will stop the unwind
52 // early -- before the function which caused the trap.
54 // To work around this, we relax that alignment to be just word-size
56 // Whitelisting the trap handlers for user space would be easy (_sigtramp) but
57 // in other environments there can be a large number of different functions
58 // involved in async traps.
60 // ToDo: When __m256 arguments are passed then stack frames should be
61 // 32 byte aligned. Decide what to do for 32 byte alignment checking
62 bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
63 // Make sure the stack call frame addresses are 4 byte aligned
64 if (cfa & (4ull - 1ull))
65 return false; // Not 4 byte aligned
67 return false; // Zero is not a valid stack address
71 bool CodeAddressIsValid(lldb::addr_t pc) override {
72 // Check whether the address is a valid 32 bit address
73 return (pc <= UINT32_MAX);
76 const lldb_private::RegisterInfo *
77 GetRegisterInfoArray(uint32_t &count) override;
81 static void Initialize();
83 static void Terminate();
85 static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
87 // PluginInterface protocol
89 static lldb_private::ConstString GetPluginNameStatic();
91 lldb_private::ConstString GetPluginName() override;
93 uint32_t GetPluginVersion() override { return 1; }
97 GetReturnValueObjectSimple(lldb_private::Thread &thread,
98 lldb_private::CompilerType &ast_type) const;
100 bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
103 ABISysV_i386(lldb::ProcessSP process_sp,
104 std::unique_ptr<llvm::MCRegisterInfo> info_up)
105 : lldb_private::ABI(std::move(process_sp), std::move(info_up)) {
106 // Call CreateInstance instead.
110 #endif // liblldb_ABISysV_i386_h_