1 //===-- PdbFPOProgramToDWARFExpression.cpp --------------------------------===//
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 #include "llvm/Support/ScopedPrinter.h"
22 
23 using namespace lldb;
24 using namespace lldb_private;
25 using namespace lldb_private::postfix;
26 
27 static uint32_t ResolveLLDBRegisterNum(llvm::StringRef reg_name, llvm::Triple::ArchType arch_type) {
28   // lookup register name to get lldb register number
29   llvm::codeview::CPUType cpu_type;
30   switch (arch_type) {
31     case llvm::Triple::ArchType::aarch64:
32       cpu_type = llvm::codeview::CPUType::ARM64;
33       break;
34 
35     default:
36       cpu_type = llvm::codeview::CPUType::X64;
37       break;
38   }
39 
40   llvm::ArrayRef<llvm::EnumEntry<uint16_t>> register_names =
41       llvm::codeview::getRegisterNames(cpu_type);
42   auto it = llvm::find_if(
43       register_names,
44       [&reg_name](const llvm::EnumEntry<uint16_t> &register_entry) {
45         return reg_name.compare_insensitive(register_entry.Name) == 0;
46       });
47 
48   if (it == register_names.end())
49     return LLDB_INVALID_REGNUM;
50 
51   auto reg_id = static_cast<llvm::codeview::RegisterId>(it->Value);
52   return npdb::GetLLDBRegisterNumber(arch_type, reg_id);
53 }
54 
55 static Node *ResolveFPOProgram(llvm::StringRef program,
56                              llvm::StringRef register_name,
57                              llvm::Triple::ArchType arch_type,
58                              llvm::BumpPtrAllocator &alloc) {
59   std::vector<std::pair<llvm::StringRef, Node *>> parsed =
60       postfix::ParseFPOProgram(program, alloc);
61 
62   for (auto it = parsed.begin(), end = parsed.end(); it != end; ++it) {
63     // Emplace valid dependent subtrees to make target assignment independent
64     // from predecessors. Resolve all other SymbolNodes as registers.
65     bool success =
66         ResolveSymbols(it->second, [&](SymbolNode &symbol) -> Node * {
67           for (const auto &pair : llvm::make_range(parsed.begin(), it)) {
68             if (pair.first == symbol.GetName())
69               return pair.second;
70           }
71 
72           uint32_t reg_num =
73               ResolveLLDBRegisterNum(symbol.GetName().drop_front(1), arch_type);
74 
75           if (reg_num == LLDB_INVALID_REGNUM)
76             return nullptr;
77 
78           return MakeNode<RegisterNode>(alloc, reg_num);
79         });
80     if (!success)
81       return nullptr;
82 
83     if (it->first == register_name) {
84       // found target assignment program - no need to parse further
85       return it->second;
86     }
87   }
88 
89   return nullptr;
90 }
91 
92 bool lldb_private::npdb::TranslateFPOProgramToDWARFExpression(
93     llvm::StringRef program, llvm::StringRef register_name,
94     llvm::Triple::ArchType arch_type, Stream &stream) {
95   llvm::BumpPtrAllocator node_alloc;
96   Node *target_program =
97       ResolveFPOProgram(program, register_name, arch_type, node_alloc);
98   if (target_program == nullptr) {
99     return false;
100   }
101 
102   ToDWARF(*target_program, stream);
103   return true;
104 }
105