1//===------------------- ABISysV_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_ABISYSV_I386_H
10#define LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_I386_H
11
12#include "Plugins/ABI/X86/ABIX86_i386.h"
13#include "lldb/lldb-private.h"
14
15class ABISysV_i386 : public ABIX86_i386 {
16public:
17 ~ABISysV_i386() override = default;
18
19 size_t GetRedZoneSize() const override {
20 return 0; // There is no red zone for i386 Architecture
21 }
22
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;
27
28 bool GetArgumentValues(lldb_private::Thread &thread,
29 lldb_private::ValueList &values) const override;
30
31 lldb_private::Status
32 SetReturnValueObject(lldb::StackFrameSP &frame_sp,
33 lldb::ValueObjectSP &new_value) override;
34
35 lldb::ValueObjectSP
36 GetReturnValueObjectImpl(lldb_private::Thread &thread,
37 lldb_private::CompilerType &type) const override;
38
39 bool
40 CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
41
42 bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
43
44 bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override {
45 return !RegisterIsCalleeSaved(reg_info);
46 }
47
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.
53 //
54 // To work around this, we relax that alignment to be just word-size
55 // (4-bytes).
56 // Allowing 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.
59
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
66 if (cfa == 0)
67 return false; // Zero is not a valid stack address
68 return true;
69 }
70
71 bool CodeAddressIsValid(lldb::addr_t pc) override {
72 // Check whether the address is a valid 32 bit address
73 return (pc <= UINT32_MAX);
74 }
75
76 // Static Functions
77
78 static void Initialize();
79
80 static void Terminate();
81
82 static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
83
84 // PluginInterface protocol
85
86 static llvm::StringRef GetPluginNameStatic() { return "sysv-i386"; }
87
88 llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
89
90protected:
91 lldb::ValueObjectSP
92 GetReturnValueObjectSimple(lldb_private::Thread &thread,
93 lldb_private::CompilerType &ast_type) const;
94
95 bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
96
97private:
98 using ABIX86_i386::ABIX86_i386; // Call CreateInstance instead.
99};
100
101#endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_I386_H
102

source code of lldb/source/Plugins/ABI/X86/ABISysV_i386.h