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 #include <optional>
24 #include <memory>
25 
26 using namespace lldb;
27 using namespace lldb_private;
28 
ClangPersistentVariables(std::shared_ptr<Target> target_sp)29 ClangPersistentVariables::ClangPersistentVariables(
30     std::shared_ptr<Target> target_sp)
31     : lldb_private::PersistentExpressionState(LLVMCastKind::eKindClang),
32       m_target_sp(target_sp) {}
33 
CreatePersistentVariable(const lldb::ValueObjectSP & valobj_sp)34 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
35     const lldb::ValueObjectSP &valobj_sp) {
36   return AddNewlyConstructedVariable(new ClangExpressionVariable(valobj_sp));
37 }
38 
CreatePersistentVariable(ExecutionContextScope * exe_scope,ConstString name,const CompilerType & compiler_type,lldb::ByteOrder byte_order,uint32_t addr_byte_size)39 ExpressionVariableSP ClangPersistentVariables::CreatePersistentVariable(
40     ExecutionContextScope *exe_scope, ConstString name,
41     const CompilerType &compiler_type, lldb::ByteOrder byte_order,
42     uint32_t addr_byte_size) {
43   return AddNewlyConstructedVariable(new ClangExpressionVariable(
44       exe_scope, name, compiler_type, byte_order, addr_byte_size));
45 }
46 
RemovePersistentVariable(lldb::ExpressionVariableSP variable)47 void ClangPersistentVariables::RemovePersistentVariable(
48     lldb::ExpressionVariableSP variable) {
49   RemoveVariable(variable);
50 
51   // Check if the removed variable was the last one that was created. If yes,
52   // reuse the variable id for the next variable.
53 
54   // Nothing to do if we have not assigned a variable id so far.
55   if (m_next_persistent_variable_id == 0)
56     return;
57 
58   llvm::StringRef name = variable->GetName().GetStringRef();
59   // Remove the prefix from the variable that only the indes is left.
60   if (!name.consume_front(GetPersistentVariablePrefix(false)))
61     return;
62 
63   // Check if the variable contained a variable id.
64   uint32_t variable_id;
65   if (name.getAsInteger(10, variable_id))
66     return;
67   // If it's the most recent variable id that was assigned, make sure that this
68   // variable id will be used for the next persistent variable.
69   if (variable_id == m_next_persistent_variable_id - 1)
70     m_next_persistent_variable_id--;
71 }
72 
73 std::optional<CompilerType>
GetCompilerTypeFromPersistentDecl(ConstString type_name)74 ClangPersistentVariables::GetCompilerTypeFromPersistentDecl(
75     ConstString type_name) {
76   PersistentDecl p = m_persistent_decls.lookup(type_name.GetCString());
77 
78   if (p.m_decl == nullptr)
79     return std::nullopt;
80 
81   if (clang::TypeDecl *tdecl = llvm::dyn_cast<clang::TypeDecl>(p.m_decl)) {
82     opaque_compiler_type_t t = static_cast<opaque_compiler_type_t>(
83         const_cast<clang::Type *>(tdecl->getTypeForDecl()));
84     return CompilerType(p.m_context, t);
85   }
86   return std::nullopt;
87 }
88 
RegisterPersistentDecl(ConstString name,clang::NamedDecl * decl,std::shared_ptr<TypeSystemClang> ctx)89 void ClangPersistentVariables::RegisterPersistentDecl(
90     ConstString name, clang::NamedDecl *decl,
91     std::shared_ptr<TypeSystemClang> ctx) {
92   PersistentDecl p = {decl, ctx};
93   m_persistent_decls.insert(std::make_pair(name.GetCString(), p));
94 
95   if (clang::EnumDecl *enum_decl = llvm::dyn_cast<clang::EnumDecl>(decl)) {
96     for (clang::EnumConstantDecl *enumerator_decl : enum_decl->enumerators()) {
97       p = {enumerator_decl, ctx};
98       m_persistent_decls.insert(std::make_pair(
99           ConstString(enumerator_decl->getNameAsString()).GetCString(), p));
100     }
101   }
102 }
103 
104 clang::NamedDecl *
GetPersistentDecl(ConstString name)105 ClangPersistentVariables::GetPersistentDecl(ConstString name) {
106   return m_persistent_decls.lookup(name.GetCString()).m_decl;
107 }
108 
109 std::shared_ptr<ClangASTImporter>
GetClangASTImporter()110 ClangPersistentVariables::GetClangASTImporter() {
111   if (!m_ast_importer_sp) {
112     m_ast_importer_sp = std::make_shared<ClangASTImporter>();
113   }
114   return m_ast_importer_sp;
115 }
116 
117 std::shared_ptr<ClangModulesDeclVendor>
GetClangModulesDeclVendor()118 ClangPersistentVariables::GetClangModulesDeclVendor() {
119   if (!m_modules_decl_vendor_sp) {
120     m_modules_decl_vendor_sp.reset(
121         ClangModulesDeclVendor::Create(*m_target_sp));
122   }
123   return m_modules_decl_vendor_sp;
124 }
125 
126 ConstString
GetNextPersistentVariableName(bool is_error)127 ClangPersistentVariables::GetNextPersistentVariableName(bool is_error) {
128   llvm::SmallString<64> name;
129   {
130     llvm::raw_svector_ostream os(name);
131     os << GetPersistentVariablePrefix(is_error)
132        << m_next_persistent_variable_id++;
133   }
134   return ConstString(name);
135 }
136