1 //===-- ASTStructExtractor.cpp ----------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "ASTStructExtractor.h"
11 
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 #include "lldb/Core/Log.h"
25 
26 using namespace llvm;
27 using namespace clang;
28 using namespace lldb_private;
29 
30 ASTStructExtractor::ASTStructExtractor(ASTConsumer *passthrough,
31                                        const char *struct_name,
32                                        ClangFunctionCaller &function) :
33     m_ast_context (NULL),
34     m_passthrough (passthrough),
35     m_passthrough_sema (NULL),
36     m_sema (NULL),
37     m_action (NULL),
38     m_function (function),
39     m_struct_name (struct_name)
40 {
41     if (!m_passthrough)
42         return;
43 
44     m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);
45 }
46 
47 ASTStructExtractor::~ASTStructExtractor()
48 {
49 }
50 
51 void
52 ASTStructExtractor::Initialize(ASTContext &Context)
53 {
54     m_ast_context = &Context;
55 
56     if (m_passthrough)
57         m_passthrough->Initialize(Context);
58 }
59 
60 void
61 ASTStructExtractor::ExtractFromFunctionDecl(FunctionDecl *F)
62 {
63     if (!F->hasBody())
64         return;
65 
66     Stmt *body_stmt = F->getBody();
67     CompoundStmt *body_compound_stmt = dyn_cast<CompoundStmt>(body_stmt);
68 
69     if (!body_compound_stmt)
70         return; // do we have to handle this?
71 
72     RecordDecl *struct_decl = NULL;
73 
74     StringRef desired_name(m_struct_name.c_str());
75 
76     for (CompoundStmt::const_body_iterator bi = body_compound_stmt->body_begin(), be = body_compound_stmt->body_end();
77          bi != be;
78          ++bi)
79     {
80         Stmt *curr_stmt = *bi;
81         DeclStmt *curr_decl_stmt = dyn_cast<DeclStmt>(curr_stmt);
82         if (!curr_decl_stmt)
83             continue;
84         DeclGroupRef decl_group = curr_decl_stmt->getDeclGroup();
85         for (Decl *candidate_decl : decl_group)
86         {
87             RecordDecl *candidate_record_decl = dyn_cast<RecordDecl>(candidate_decl);
88             if (!candidate_record_decl)
89                 continue;
90             if (candidate_record_decl->getName() == desired_name)
91             {
92                 struct_decl = candidate_record_decl;
93                 break;
94             }
95         }
96         if (struct_decl)
97             break;
98     }
99 
100     if (!struct_decl)
101         return;
102 
103     const ASTRecordLayout* struct_layout(&m_ast_context->getASTRecordLayout (struct_decl));
104 
105     if (!struct_layout)
106         return;
107 
108     m_function.m_struct_size = struct_layout->getSize().getQuantity(); // TODO Store m_struct_size as CharUnits
109     m_function.m_return_offset = struct_layout->getFieldOffset(struct_layout->getFieldCount() - 1) / 8;
110     m_function.m_return_size = struct_layout->getDataSize().getQuantity() - m_function.m_return_offset;
111 
112     for (unsigned field_index = 0, num_fields = struct_layout->getFieldCount();
113          field_index < num_fields;
114          ++field_index)
115     {
116         m_function.m_member_offsets.push_back(struct_layout->getFieldOffset(field_index) / 8);
117     }
118 
119     m_function.m_struct_valid = true;
120 }
121 
122 void
123 ASTStructExtractor::ExtractFromTopLevelDecl(Decl* D)
124 {
125     LinkageSpecDecl *linkage_spec_decl = dyn_cast<LinkageSpecDecl>(D);
126 
127     if (linkage_spec_decl)
128     {
129         RecordDecl::decl_iterator decl_iterator;
130 
131         for (decl_iterator = linkage_spec_decl->decls_begin();
132              decl_iterator != linkage_spec_decl->decls_end();
133              ++decl_iterator)
134         {
135             ExtractFromTopLevelDecl(*decl_iterator);
136         }
137     }
138 
139     FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D);
140 
141     if (m_ast_context &&
142         function_decl &&
143         !m_function.m_wrapper_function_name.compare(function_decl->getNameAsString().c_str()))
144     {
145         ExtractFromFunctionDecl(function_decl);
146     }
147 }
148 
149 bool
150 ASTStructExtractor::HandleTopLevelDecl(DeclGroupRef D)
151 {
152     DeclGroupRef::iterator decl_iterator;
153 
154     for (decl_iterator = D.begin();
155          decl_iterator != D.end();
156          ++decl_iterator)
157     {
158         Decl *decl = *decl_iterator;
159 
160         ExtractFromTopLevelDecl(decl);
161     }
162 
163     if (m_passthrough)
164         return m_passthrough->HandleTopLevelDecl(D);
165     return true;
166 }
167 
168 void
169 ASTStructExtractor::HandleTranslationUnit(ASTContext &Ctx)
170 {
171     if (m_passthrough)
172         m_passthrough->HandleTranslationUnit(Ctx);
173 }
174 
175 void
176 ASTStructExtractor::HandleTagDeclDefinition(TagDecl *D)
177 {
178     if (m_passthrough)
179         m_passthrough->HandleTagDeclDefinition(D);
180 }
181 
182 void
183 ASTStructExtractor::CompleteTentativeDefinition(VarDecl *D)
184 {
185     if (m_passthrough)
186         m_passthrough->CompleteTentativeDefinition(D);
187 }
188 
189 void
190 ASTStructExtractor::HandleVTable(CXXRecordDecl *RD)
191 {
192     if (m_passthrough)
193         m_passthrough->HandleVTable(RD);
194 }
195 
196 void
197 ASTStructExtractor::PrintStats()
198 {
199     if (m_passthrough)
200         m_passthrough->PrintStats();
201 }
202 
203 void
204 ASTStructExtractor::InitializeSema(Sema &S)
205 {
206     m_sema = &S;
207     m_action = reinterpret_cast<Action*>(m_sema);
208 
209     if (m_passthrough_sema)
210         m_passthrough_sema->InitializeSema(S);
211 }
212 
213 void
214 ASTStructExtractor::ForgetSema()
215 {
216     m_sema = NULL;
217     m_action = NULL;
218 
219     if (m_passthrough_sema)
220         m_passthrough_sema->ForgetSema();
221 }
222