1//===-- PdbFPOProgramToDWARFExpression.cpp ----------------------*- 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#include "PdbFPOProgramToDWARFExpression.h"
10#include "CodeViewRegisterMapping.h"
11
12#include "lldb/Core/StreamBuffer.h"
13#include "lldb/Symbol/PostfixExpression.h"
14#include "lldb/Utility/LLDBAssert.h"
15#include "lldb/Utility/Stream.h"
16#include "llvm/ADT/DenseMap.h"
17
18#include "llvm/ADT/StringExtras.h"
19#include "llvm/DebugInfo/CodeView/CodeView.h"
20#include "llvm/DebugInfo/CodeView/EnumTables.h"
21
22using namespace lldb;
23using namespace lldb_private;
24using namespace lldb_private::postfix;
25
26static uint32_t ResolveLLDBRegisterNum(llvm::StringRef reg_name, llvm::Triple::ArchType arch_type) {
27  // lookup register name to get lldb register number
28  llvm::codeview::CPUType cpu_type;
29  switch (arch_type) {
30    case llvm::Triple::ArchType::aarch64:
31      cpu_type = llvm::codeview::CPUType::ARM64;
32      break;
33
34    default:
35      cpu_type = llvm::codeview::CPUType::X64;
36      break;
37  }
38
39  llvm::ArrayRef<llvm::EnumEntry<uint16_t>> register_names =
40      llvm::codeview::getRegisterNames(cpu_type);
41  auto it = llvm::find_if(
42      register_names,
43      [&reg_name](const llvm::EnumEntry<uint16_t> &register_entry) {
44        return reg_name.compare_lower(register_entry.Name) == 0;
45      });
46
47  if (it == register_names.end())
48    return LLDB_INVALID_REGNUM;
49
50  auto reg_id = static_cast<llvm::codeview::RegisterId>(it->Value);
51  return npdb::GetLLDBRegisterNumber(arch_type, reg_id);
52}
53
54static Node *ResolveFPOProgram(llvm::StringRef program,
55                             llvm::StringRef register_name,
56                             llvm::Triple::ArchType arch_type,
57                             llvm::BumpPtrAllocator &alloc) {
58  std::vector<std::pair<llvm::StringRef, Node *>> parsed =
59      postfix::ParseFPOProgram(program, alloc);
60
61  for (auto it = parsed.begin(), end = parsed.end(); it != end; ++it) {
62    // Emplace valid dependent subtrees to make target assignment independent
63    // from predecessors. Resolve all other SymbolNodes as registers.
64    bool success =
65        ResolveSymbols(it->second, [&](SymbolNode &symbol) -> Node * {
66          for (const auto &pair : llvm::make_range(parsed.begin(), it)) {
67            if (pair.first == symbol.GetName())
68              return pair.second;
69          }
70
71          uint32_t reg_num =
72              ResolveLLDBRegisterNum(symbol.GetName().drop_front(1), arch_type);
73
74          if (reg_num == LLDB_INVALID_REGNUM)
75            return nullptr;
76
77          return MakeNode<RegisterNode>(alloc, reg_num);
78        });
79    if (!success)
80      return nullptr;
81
82    if (it->first == register_name) {
83      // found target assignment program - no need to parse further
84      return it->second;
85    }
86  }
87
88  return nullptr;
89}
90
91bool lldb_private::npdb::TranslateFPOProgramToDWARFExpression(
92    llvm::StringRef program, llvm::StringRef register_name,
93    llvm::Triple::ArchType arch_type, Stream &stream) {
94  llvm::BumpPtrAllocator node_alloc;
95  Node *target_program =
96      ResolveFPOProgram(program, register_name, arch_type, node_alloc);
97  if (target_program == nullptr) {
98    return false;
99  }
100
101  ToDWARF(*target_program, stream);
102  return true;
103}
104