ASTStructExtractor.cpp revision 360784 
1//===-- ASTStructExtractor.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 "ASTStructExtractor.h"
10
11#include "lldb/Utility/Log.h"
12#include "stdlib.h"
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/Decl.h"
15#include "clang/AST/DeclCXX.h"
16#include "clang/AST/DeclGroup.h"
17#include "clang/AST/Expr.h"
18#include "clang/AST/RecordLayout.h"
19#include "clang/AST/Stmt.h"
20#include "clang/Parse/Parser.h"
21#include "clang/Sema/Sema.h"
22#include "llvm/Support/Casting.h"
23#include "llvm/Support/raw_ostream.h"
24
25using namespace llvm;
26using namespace clang;
27using namespace lldb_private;
28
29ASTStructExtractor::ASTStructExtractor(ASTConsumer *passthrough,
30                                       const char *struct_name,
31                                       ClangFunctionCaller &function)
32    : m_ast_context(nullptr), m_passthrough(passthrough),
33      m_passthrough_sema(nullptr), m_sema(nullptr), m_function(function),
34      m_struct_name(struct_name) {
35  if (!m_passthrough)
36    return;
37
38  m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);
39}
40
41ASTStructExtractor::~ASTStructExtractor() {}
42
43void ASTStructExtractor::Initialize(ASTContext &Context) {
44  m_ast_context = &Context;
45
46  if (m_passthrough)
47    m_passthrough->Initialize(Context);
48}
49
50void ASTStructExtractor::ExtractFromFunctionDecl(FunctionDecl *F) {
51  if (!F->hasBody())
52    return;
53
54  Stmt *body_stmt = F->getBody();
55  CompoundStmt *body_compound_stmt = dyn_cast<CompoundStmt>(body_stmt);
56
57  if (!body_compound_stmt)
58    return; // do we have to handle this?
59
60  RecordDecl *struct_decl = nullptr;
61
62  StringRef desired_name(m_struct_name);
63
64  for (CompoundStmt::const_body_iterator bi = body_compound_stmt->body_begin(),
65                                         be = body_compound_stmt->body_end();
66       bi != be; ++bi) {
67    Stmt *curr_stmt = *bi;
68    DeclStmt *curr_decl_stmt = dyn_cast<DeclStmt>(curr_stmt);
69    if (!curr_decl_stmt)
70      continue;
71    DeclGroupRef decl_group = curr_decl_stmt->getDeclGroup();
72    for (Decl *candidate_decl : decl_group) {
73      RecordDecl *candidate_record_decl = dyn_cast<RecordDecl>(candidate_decl);
74      if (!candidate_record_decl)
75        continue;
76      if (candidate_record_decl->getName() == desired_name) {
77        struct_decl = candidate_record_decl;
78        break;
79      }
80    }
81    if (struct_decl)
82      break;
83  }
84
85  if (!struct_decl)
86    return;
87
88  const ASTRecordLayout *struct_layout(
89      &m_ast_context->getASTRecordLayout(struct_decl));
90
91  if (!struct_layout)
92    return;
93
94  m_function.m_struct_size =
95      struct_layout->getSize()
96          .getQuantity(); // TODO Store m_struct_size as CharUnits
97  m_function.m_return_offset =
98      struct_layout->getFieldOffset(struct_layout->getFieldCount() - 1) / 8;
99  m_function.m_return_size =
100      struct_layout->getDataSize().getQuantity() - m_function.m_return_offset;
101
102  for (unsigned field_index = 0, num_fields = struct_layout->getFieldCount();
103       field_index < num_fields; ++field_index) {
104    m_function.m_member_offsets.push_back(
105        struct_layout->getFieldOffset(field_index) / 8);
106  }
107
108  m_function.m_struct_valid = true;
109}
110
111void ASTStructExtractor::ExtractFromTopLevelDecl(Decl *D) {
112  LinkageSpecDecl *linkage_spec_decl = dyn_cast<LinkageSpecDecl>(D);
113
114  if (linkage_spec_decl) {
115    RecordDecl::decl_iterator decl_iterator;
116
117    for (decl_iterator = linkage_spec_decl->decls_begin();
118         decl_iterator != linkage_spec_decl->decls_end(); ++decl_iterator) {
119      ExtractFromTopLevelDecl(*decl_iterator);
120    }
121  }
122
123  FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D);
124
125  if (m_ast_context && function_decl &&
126      !m_function.m_wrapper_function_name.compare(
127          function_decl->getNameAsString())) {
128    ExtractFromFunctionDecl(function_decl);
129  }
130}
131
132bool ASTStructExtractor::HandleTopLevelDecl(DeclGroupRef D) {
133  DeclGroupRef::iterator decl_iterator;
134
135  for (decl_iterator = D.begin(); decl_iterator != D.end(); ++decl_iterator) {
136    Decl *decl = *decl_iterator;
137
138    ExtractFromTopLevelDecl(decl);
139  }
140
141  if (m_passthrough)
142    return m_passthrough->HandleTopLevelDecl(D);
143  return true;
144}
145
146void ASTStructExtractor::HandleTranslationUnit(ASTContext &Ctx) {
147  if (m_passthrough)
148    m_passthrough->HandleTranslationUnit(Ctx);
149}
150
151void ASTStructExtractor::HandleTagDeclDefinition(TagDecl *D) {
152  if (m_passthrough)
153    m_passthrough->HandleTagDeclDefinition(D);
154}
155
156void ASTStructExtractor::CompleteTentativeDefinition(VarDecl *D) {
157  if (m_passthrough)
158    m_passthrough->CompleteTentativeDefinition(D);
159}
160
161void ASTStructExtractor::HandleVTable(CXXRecordDecl *RD) {
162  if (m_passthrough)
163    m_passthrough->HandleVTable(RD);
164}
165
166void ASTStructExtractor::PrintStats() {
167  if (m_passthrough)
168    m_passthrough->PrintStats();
169}
170
171void ASTStructExtractor::InitializeSema(Sema &S) {
172  m_sema = &S;
173
174  if (m_passthrough_sema)
175    m_passthrough_sema->InitializeSema(S);
176}
177
178void ASTStructExtractor::ForgetSema() {
179  m_sema = nullptr;
180
181  if (m_passthrough_sema)
182    m_passthrough_sema->ForgetSema();
183}
184