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 22 using namespace lldb; 23 using namespace lldb_private; 24 using namespace lldb_private::postfix; 25 26 static uint32_t ResolveLLDBRegisterNum(llvm::StringRef reg_name, llvm::Triple::ArchType arch_type) { 27 // lookup register name to get lldb register number 28 llvm::ArrayRef<llvm::EnumEntry<uint16_t>> register_names = 29 llvm::codeview::getRegisterNames(); 30 auto it = llvm::find_if( 31 register_names, 32 [®_name](const llvm::EnumEntry<uint16_t> ®ister_entry) { 33 return reg_name.compare_lower(register_entry.Name) == 0; 34 }); 35 36 if (it == register_names.end()) 37 return LLDB_INVALID_REGNUM; 38 39 auto reg_id = static_cast<llvm::codeview::RegisterId>(it->Value); 40 return npdb::GetLLDBRegisterNumber(arch_type, reg_id); 41 } 42 43 static bool ParseFPOSingleAssignmentProgram(llvm::StringRef program, 44 llvm::BumpPtrAllocator &alloc, 45 llvm::StringRef ®ister_name, 46 Node *&ast) { 47 // lvalue of assignment is always first token 48 // rvalue program goes next 49 std::tie(register_name, program) = getToken(program); 50 if (register_name.empty()) 51 return false; 52 53 ast = Parse(program, alloc); 54 return ast != nullptr; 55 } 56 57 static Node *ParseFPOProgram(llvm::StringRef program, 58 llvm::StringRef register_name, 59 llvm::Triple::ArchType arch_type, 60 llvm::BumpPtrAllocator &alloc) { 61 llvm::DenseMap<llvm::StringRef, Node *> dependent_programs; 62 63 size_t cur = 0; 64 while (true) { 65 size_t assign_index = program.find('=', cur); 66 if (assign_index == llvm::StringRef::npos) { 67 llvm::StringRef tail = program.slice(cur, llvm::StringRef::npos); 68 if (!tail.trim().empty()) { 69 // missing assign operator 70 return nullptr; 71 } 72 break; 73 } 74 llvm::StringRef assignment_program = program.slice(cur, assign_index); 75 76 llvm::StringRef lvalue_name; 77 Node *rvalue_ast = nullptr; 78 if (!ParseFPOSingleAssignmentProgram(assignment_program, alloc, lvalue_name, 79 rvalue_ast)) { 80 return nullptr; 81 } 82 83 lldbassert(rvalue_ast); 84 85 // Emplace valid dependent subtrees to make target assignment independent 86 // from predecessors. Resolve all other SymbolNodes as registers. 87 bool success = 88 ResolveSymbols(rvalue_ast, [&](SymbolNode &symbol) -> Node * { 89 if (Node *node = dependent_programs.lookup(symbol.GetName())) 90 return node; 91 uint32_t reg_num = 92 ResolveLLDBRegisterNum(symbol.GetName().drop_front(1), arch_type); 93 94 if (reg_num == LLDB_INVALID_REGNUM) 95 return nullptr; 96 97 return MakeNode<RegisterNode>(alloc, reg_num); 98 }); 99 if (!success) 100 return nullptr; 101 102 if (lvalue_name == register_name) { 103 // found target assignment program - no need to parse further 104 return rvalue_ast; 105 } 106 107 dependent_programs[lvalue_name] = rvalue_ast; 108 cur = assign_index + 1; 109 } 110 111 return nullptr; 112 } 113 114 bool lldb_private::npdb::TranslateFPOProgramToDWARFExpression( 115 llvm::StringRef program, llvm::StringRef register_name, 116 llvm::Triple::ArchType arch_type, Stream &stream) { 117 llvm::BumpPtrAllocator node_alloc; 118 Node *target_program = 119 ParseFPOProgram(program, register_name, arch_type, node_alloc); 120 if (target_program == nullptr) { 121 return false; 122 } 123 124 ToDWARF(*target_program, stream); 125 return true; 126 } 127