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 #include "ClangModulesDeclVendor.h"
12 
13 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
14 #include "lldb/Core/Value.h"
15 #include "lldb/Target/Target.h"
16 #include "lldb/Utility/DataExtractor.h"
17 #include "lldb/Utility/Log.h"
18 #include "lldb/Utility/StreamString.h"
19 
20 #include "clang/AST/Decl.h"
21 
22 #include "llvm/ADT/StringMap.h"
23 
24 using namespace lldb;
25 using namespace lldb_private;
26 
27 ClangPersistentVariables::ClangPersistentVariables(
28     std::shared_ptr<Target> target_sp)
29     : lldb_private::PersistentExpressionState(LLVMCastKind::eKindClang),
30       m_target_sp(target_sp) {}
31 
32 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
33     const lldb::ValueObjectSP &valobj_sp) {
34   return AddNewlyConstructedVariable(new ClangExpressionVariable(valobj_sp));
35 }
36 
37 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
38     ExecutionContextScope *exe_scope, ConstString name,
39     const CompilerType &compiler_type, lldb::ByteOrder byte_order,
40     uint32_t addr_byte_size) {
41   return AddNewlyConstructedVariable(new ClangExpressionVariable(
42       exe_scope, name, compiler_type, byte_order, addr_byte_size));
43 }
44 
45 void ClangPersistentVariables::RemovePersistentVariable(
46     lldb::ExpressionVariableSP variable) {
47   RemoveVariable(variable);
48 
49   // Check if the removed variable was the last one that was created. If yes,
50   // reuse the variable id for the next variable.
51 
52   // Nothing to do if we have not assigned a variable id so far.
53   if (m_next_persistent_variable_id == 0)
54     return;
55 
56   llvm::StringRef name = variable->GetName().GetStringRef();
57   // Remove the prefix from the variable that only the indes is left.
58   if (!name.consume_front(GetPersistentVariablePrefix(false)))
59     return;
60 
61   // Check if the variable contained a variable id.
62   uint32_t variable_id;
63   if (name.getAsInteger(10, variable_id))
64     return;
65   // If it's the most recent variable id that was assigned, make sure that this
66   // variable id will be used for the next persistent variable.
67   if (variable_id == m_next_persistent_variable_id - 1)
68     m_next_persistent_variable_id--;
69 }
70 
71 llvm::Optional<CompilerType>
72 ClangPersistentVariables::GetCompilerTypeFromPersistentDecl(
73     ConstString type_name) {
74   PersistentDecl p = m_persistent_decls.lookup(type_name.GetCString());
75 
76   if (p.m_decl == nullptr)
77     return llvm::None;
78 
79   if (clang::TypeDecl *tdecl = llvm::dyn_cast<clang::TypeDecl>(p.m_decl)) {
80     opaque_compiler_type_t t = static_cast<opaque_compiler_type_t>(
81         const_cast<clang::Type *>(tdecl->getTypeForDecl()));
82     return CompilerType(p.m_context, t);
83   }
84   return llvm::None;
85 }
86 
87 void ClangPersistentVariables::RegisterPersistentDecl(ConstString name,
88                                                       clang::NamedDecl *decl,
89                                                       TypeSystemClang *ctx) {
90   PersistentDecl p = {decl, ctx};
91   m_persistent_decls.insert(std::make_pair(name.GetCString(), p));
92 
93   if (clang::EnumDecl *enum_decl = llvm::dyn_cast<clang::EnumDecl>(decl)) {
94     for (clang::EnumConstantDecl *enumerator_decl : enum_decl->enumerators()) {
95       p = {enumerator_decl, ctx};
96       m_persistent_decls.insert(std::make_pair(
97           ConstString(enumerator_decl->getNameAsString()).GetCString(), p));
98     }
99   }
100 }
101 
102 clang::NamedDecl *
103 ClangPersistentVariables::GetPersistentDecl(ConstString name) {
104   return m_persistent_decls.lookup(name.GetCString()).m_decl;
105 }
106 
107 std::shared_ptr<ClangASTImporter>
108 ClangPersistentVariables::GetClangASTImporter() {
109   if (!m_ast_importer_sp) {
110     m_ast_importer_sp = std::make_shared<ClangASTImporter>();
111   }
112   return m_ast_importer_sp;
113 }
114 
115 std::shared_ptr<ClangModulesDeclVendor>
116 ClangPersistentVariables::GetClangModulesDeclVendor() {
117   if (!m_modules_decl_vendor_sp) {
118     m_modules_decl_vendor_sp.reset(
119         ClangModulesDeclVendor::Create(*m_target_sp.get()));
120   }
121   return m_modules_decl_vendor_sp;
122 }
123 
124 ConstString
125 ClangPersistentVariables::GetNextPersistentVariableName(bool is_error) {
126   llvm::SmallString<64> name;
127   {
128     llvm::raw_svector_ostream os(name);
129     os << GetPersistentVariablePrefix(is_error)
130        << m_next_persistent_variable_id++;
131   }
132   return ConstString(name);
133 }
134