summaryrefslogtreecommitdiff
path: root/source/Target/ABI.cpp
blob: 72f58be5a3d4f869866bd2d2cc43c5d9ef9bb514 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
//===-- ABI.cpp -------------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Target/ABI.h"
#include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"

using namespace lldb;
using namespace lldb_private;

ABISP
ABI::FindPlugin(lldb::ProcessSP process_sp, const ArchSpec &arch) {
  ABISP abi_sp;
  ABICreateInstance create_callback;

  for (uint32_t idx = 0;
       (create_callback = PluginManager::GetABICreateCallbackAtIndex(idx)) !=
       nullptr;
       ++idx) {
    abi_sp = create_callback(process_sp, arch);

    if (abi_sp)
      return abi_sp;
  }
  abi_sp.reset();
  return abi_sp;
}

ABI::~ABI() = default;

bool ABI::GetRegisterInfoByName(const ConstString &name, RegisterInfo &info) {
  uint32_t count = 0;
  const RegisterInfo *register_info_array = GetRegisterInfoArray(count);
  if (register_info_array) {
    const char *unique_name_cstr = name.GetCString();
    uint32_t i;
    for (i = 0; i < count; ++i) {
      if (register_info_array[i].name == unique_name_cstr) {
        info = register_info_array[i];
        return true;
      }
    }
    for (i = 0; i < count; ++i) {
      if (register_info_array[i].alt_name == unique_name_cstr) {
        info = register_info_array[i];
        return true;
      }
    }
  }
  return false;
}

bool ABI::GetRegisterInfoByKind(RegisterKind reg_kind, uint32_t reg_num,
                                RegisterInfo &info) {
  if (reg_kind < eRegisterKindEHFrame || reg_kind >= kNumRegisterKinds)
    return false;

  uint32_t count = 0;
  const RegisterInfo *register_info_array = GetRegisterInfoArray(count);
  if (register_info_array) {
    for (uint32_t i = 0; i < count; ++i) {
      if (register_info_array[i].kinds[reg_kind] == reg_num) {
        info = register_info_array[i];
        return true;
      }
    }
  }
  return false;
}

ValueObjectSP ABI::GetReturnValueObject(Thread &thread, CompilerType &ast_type,
                                        bool persistent) const {
  if (!ast_type.IsValid())
    return ValueObjectSP();

  ValueObjectSP return_valobj_sp;

  return_valobj_sp = GetReturnValueObjectImpl(thread, ast_type);
  if (!return_valobj_sp)
    return return_valobj_sp;

  // Now turn this into a persistent variable.
  // FIXME: This code is duplicated from Target::EvaluateExpression, and it is
  // used in similar form in a couple
  // of other places.  Figure out the correct Create function to do all this
  // work.

  if (persistent) {
    PersistentExpressionState *persistent_expression_state =
        thread.CalculateTarget()->GetPersistentExpressionStateForLanguage(
            ast_type.GetMinimumLanguage());

    if (!persistent_expression_state)
      return ValueObjectSP();

    ConstString persistent_variable_name(
        persistent_expression_state->GetNextPersistentVariableName());

    lldb::ValueObjectSP const_valobj_sp;

    // Check in case our value is already a constant value
    if (return_valobj_sp->GetIsConstant()) {
      const_valobj_sp = return_valobj_sp;
      const_valobj_sp->SetName(persistent_variable_name);
    } else
      const_valobj_sp =
          return_valobj_sp->CreateConstantValue(persistent_variable_name);

    lldb::ValueObjectSP live_valobj_sp = return_valobj_sp;

    return_valobj_sp = const_valobj_sp;

    ExpressionVariableSP clang_expr_variable_sp(
        persistent_expression_state->CreatePersistentVariable(
            return_valobj_sp));

    assert(clang_expr_variable_sp);

    // Set flags and live data as appropriate

    const Value &result_value = live_valobj_sp->GetValue();

    switch (result_value.GetValueType()) {
    case Value::eValueTypeHostAddress:
    case Value::eValueTypeFileAddress:
      // we don't do anything with these for now
      break;
    case Value::eValueTypeScalar:
    case Value::eValueTypeVector:
      clang_expr_variable_sp->m_flags |=
          ClangExpressionVariable::EVIsFreezeDried;
      clang_expr_variable_sp->m_flags |=
          ClangExpressionVariable::EVIsLLDBAllocated;
      clang_expr_variable_sp->m_flags |=
          ClangExpressionVariable::EVNeedsAllocation;
      break;
    case Value::eValueTypeLoadAddress:
      clang_expr_variable_sp->m_live_sp = live_valobj_sp;
      clang_expr_variable_sp->m_flags |=
          ClangExpressionVariable::EVIsProgramReference;
      break;
    }

    return_valobj_sp = clang_expr_variable_sp->GetValueObject();
  }
  return return_valobj_sp;
}

ValueObjectSP ABI::GetReturnValueObject(Thread &thread, llvm::Type &ast_type,
                                        bool persistent) const {
  ValueObjectSP return_valobj_sp;
  return_valobj_sp = GetReturnValueObjectImpl(thread, ast_type);
  return return_valobj_sp;
}

// specialized to work with llvm IR types
//
// for now we will specify a default implementation so that we don't need to
// modify other ABIs
lldb::ValueObjectSP ABI::GetReturnValueObjectImpl(Thread &thread,
                                                  llvm::Type &ir_type) const {
  ValueObjectSP return_valobj_sp;

  /* this is a dummy and will only be called if an ABI does not override this */

  return return_valobj_sp;
}

bool ABI::PrepareTrivialCall(Thread &thread, lldb::addr_t sp,
                             lldb::addr_t functionAddress,
                             lldb::addr_t returnAddress, llvm::Type &returntype,
                             llvm::ArrayRef<ABI::CallArgument> args) const {
  // dummy prepare trivial call
  llvm_unreachable("Should never get here!");
}

bool ABI::GetFallbackRegisterLocation(
    const RegisterInfo *reg_info,
    UnwindPlan::Row::RegisterLocation &unwind_regloc) {
  // Did the UnwindPlan fail to give us the caller's stack pointer?
  // The stack pointer is defined to be the same as THIS frame's CFA, so return
  // the CFA value as
  // the caller's stack pointer.  This is true on x86-32/x86-64 at least.
  if (reg_info->kinds[eRegisterKindGeneric] == LLDB_REGNUM_GENERIC_SP) {
    unwind_regloc.SetIsCFAPlusOffset(0);
    return true;
  }

  // If a volatile register is being requested, we don't want to forward the
  // next frame's register contents
  // up the stack -- the register is not retrievable at this frame.
  if (RegisterIsVolatile(reg_info)) {
    unwind_regloc.SetUndefined();
    return true;
  }

  return false;
}