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 lldb::UnwindPlanSP CreateFunctionEntryUnwindPlan() override;
40
41 lldb::UnwindPlanSP CreateDefaultUnwindPlan() override;
42
43 bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override {
44 return !RegisterIsCalleeSaved(reg_info);
45 }
46
47 // The SysV i386 ABI requires that stack frames be 16 byte aligned.
48 // When there is a trap handler on the stack, e.g. _sigtramp in userland
49 // code, we've seen that the stack pointer is often not aligned properly
50 // before the handler is invoked. This means that lldb will stop the unwind
51 // early -- before the function which caused the trap.
52 //
53 // To work around this, we relax that alignment to be just word-size
54 // (4-bytes).
55 // Allowing the trap handlers for user space would be easy (_sigtramp) but
56 // in other environments there can be a large number of different functions
57 // involved in async traps.
58
59 // ToDo: When __m256 arguments are passed then stack frames should be
60 // 32 byte aligned. Decide what to do for 32 byte alignment checking
61 bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
62 // Make sure the stack call frame addresses are 4 byte aligned
63 if (cfa & (4ull - 1ull))
64 return false; // Not 4 byte aligned
65 if (cfa == 0)
66 return false; // Zero is not a valid stack address
67 return true;
68 }
69
70 bool CodeAddressIsValid(lldb::addr_t pc) override {
71 // Check whether the address is a valid 32 bit address
72 return (pc <= UINT32_MAX);
73 }
74
75 // Static Functions
76
77 static void Initialize();
78
79 static void Terminate();
80
81 static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
82
83 // PluginInterface protocol
84
85 static llvm::StringRef GetPluginNameStatic() { return "sysv-i386"; }
86
87 llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
88
89protected:
90 lldb::ValueObjectSP
91 GetReturnValueObjectSimple(lldb_private::Thread &thread,
92 lldb_private::CompilerType &ast_type) const;
93
94 bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
95
96private:
97 using ABIX86_i386::ABIX86_i386; // Call CreateInstance instead.
98};
99
100#endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_I386_H
101

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