1 //===-- ClangPersistentVariables.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 "ClangPersistentVariables.h"
10 #include "ClangASTImporter.h"
11 
12 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
13 #include "lldb/Core/Value.h"
14 #include "lldb/Target/Target.h"
15 #include "lldb/Utility/DataExtractor.h"
16 #include "lldb/Utility/Log.h"
17 #include "lldb/Utility/StreamString.h"
18 
19 #include "clang/AST/Decl.h"
20 
21 #include "llvm/ADT/StringMap.h"
22 
23 using namespace lldb;
24 using namespace lldb_private;
25 
26 ClangPersistentVariables::ClangPersistentVariables()
27     : lldb_private::PersistentExpressionState(LLVMCastKind::eKindClang) {}
28 
29 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
30     const lldb::ValueObjectSP &valobj_sp) {
31   return AddNewlyConstructedVariable(new ClangExpressionVariable(valobj_sp));
32 }
33 
34 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
35     ExecutionContextScope *exe_scope, ConstString name,
36     const CompilerType &compiler_type, lldb::ByteOrder byte_order,
37     uint32_t addr_byte_size) {
38   return AddNewlyConstructedVariable(new ClangExpressionVariable(
39       exe_scope, name, compiler_type, byte_order, addr_byte_size));
40 }
41 
42 void ClangPersistentVariables::RemovePersistentVariable(
43     lldb::ExpressionVariableSP variable) {
44   RemoveVariable(variable);
45 
46   // Check if the removed variable was the last one that was created. If yes,
47   // reuse the variable id for the next variable.
48 
49   // Nothing to do if we have not assigned a variable id so far.
50   if (m_next_persistent_variable_id == 0)
51     return;
52 
53   llvm::StringRef name = variable->GetName().GetStringRef();
54   // Remove the prefix from the variable that only the indes is left.
55   if (!name.consume_front(GetPersistentVariablePrefix(false)))
56     return;
57 
58   // Check if the variable contained a variable id.
59   uint32_t variable_id;
60   if (name.getAsInteger(10, variable_id))
61     return;
62   // If it's the most recent variable id that was assigned, make sure that this
63   // variable id will be used for the next persistent variable.
64   if (variable_id == m_next_persistent_variable_id - 1)
65     m_next_persistent_variable_id--;
66 }
67 
68 llvm::Optional<CompilerType>
69 ClangPersistentVariables::GetCompilerTypeFromPersistentDecl(
70     ConstString type_name) {
71   PersistentDecl p = m_persistent_decls.lookup(type_name.GetCString());
72 
73   if (p.m_decl == nullptr)
74     return llvm::None;
75 
76   if (clang::TypeDecl *tdecl = llvm::dyn_cast<clang::TypeDecl>(p.m_decl)) {
77     opaque_compiler_type_t t = static_cast<opaque_compiler_type_t>(
78         const_cast<clang::Type *>(tdecl->getTypeForDecl()));
79     return CompilerType(p.m_context, t);
80   }
81   return llvm::None;
82 }
83 
84 void ClangPersistentVariables::RegisterPersistentDecl(ConstString name,
85                                                       clang::NamedDecl *decl,
86                                                       TypeSystemClang *ctx) {
87   PersistentDecl p = {decl, ctx};
88   m_persistent_decls.insert(std::make_pair(name.GetCString(), p));
89 
90   if (clang::EnumDecl *enum_decl = llvm::dyn_cast<clang::EnumDecl>(decl)) {
91     for (clang::EnumConstantDecl *enumerator_decl : enum_decl->enumerators()) {
92       p = {enumerator_decl, ctx};
93       m_persistent_decls.insert(std::make_pair(
94           ConstString(enumerator_decl->getNameAsString()).GetCString(), p));
95     }
96   }
97 }
98 
99 clang::NamedDecl *
100 ClangPersistentVariables::GetPersistentDecl(ConstString name) {
101   return m_persistent_decls.lookup(name.GetCString()).m_decl;
102 }
103 
104 std::shared_ptr<ClangASTImporter>
105 ClangPersistentVariables::GetClangASTImporter() {
106   if (!m_ast_importer_sp) {
107     m_ast_importer_sp = std::make_shared<ClangASTImporter>();
108   }
109   return m_ast_importer_sp;
110 }
111 
112 ConstString
113 ClangPersistentVariables::GetNextPersistentVariableName(bool is_error) {
114   llvm::SmallString<64> name;
115   {
116     llvm::raw_svector_ostream os(name);
117     os << GetPersistentVariablePrefix(is_error)
118        << m_next_persistent_variable_id++;
119   }
120   return ConstString(name);
121 }
122