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 "lldb/Core/Log.h"
13 #include "stdlib.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclGroup.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/RecordLayout.h"
20 #include "clang/AST/Stmt.h"
21 #include "clang/Parse/Parser.h"
22 #include "clang/Sema/Sema.h"
23 #include "llvm/Support/Casting.h"
24 #include "llvm/Support/raw_ostream.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), m_passthrough(passthrough), m_passthrough_sema(NULL),
34       m_sema(NULL), m_action(NULL), m_function(function),
35       m_struct_name(struct_name) {
36   if (!m_passthrough)
37     return;
38 
39   m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);
40 }
41 
42 ASTStructExtractor::~ASTStructExtractor() {}
43 
44 void ASTStructExtractor::Initialize(ASTContext &Context) {
45   m_ast_context = &Context;
46 
47   if (m_passthrough)
48     m_passthrough->Initialize(Context);
49 }
50 
51 void ASTStructExtractor::ExtractFromFunctionDecl(FunctionDecl *F) {
52   if (!F->hasBody())
53     return;
54 
55   Stmt *body_stmt = F->getBody();
56   CompoundStmt *body_compound_stmt = dyn_cast<CompoundStmt>(body_stmt);
57 
58   if (!body_compound_stmt)
59     return; // do we have to handle this?
60 
61   RecordDecl *struct_decl = NULL;
62 
63   StringRef desired_name(m_struct_name.c_str());
64 
65   for (CompoundStmt::const_body_iterator bi = body_compound_stmt->body_begin(),
66                                          be = body_compound_stmt->body_end();
67        bi != be; ++bi) {
68     Stmt *curr_stmt = *bi;
69     DeclStmt *curr_decl_stmt = dyn_cast<DeclStmt>(curr_stmt);
70     if (!curr_decl_stmt)
71       continue;
72     DeclGroupRef decl_group = curr_decl_stmt->getDeclGroup();
73     for (Decl *candidate_decl : decl_group) {
74       RecordDecl *candidate_record_decl = dyn_cast<RecordDecl>(candidate_decl);
75       if (!candidate_record_decl)
76         continue;
77       if (candidate_record_decl->getName() == desired_name) {
78         struct_decl = candidate_record_decl;
79         break;
80       }
81     }
82     if (struct_decl)
83       break;
84   }
85 
86   if (!struct_decl)
87     return;
88 
89   const ASTRecordLayout *struct_layout(
90       &m_ast_context->getASTRecordLayout(struct_decl));
91 
92   if (!struct_layout)
93     return;
94 
95   m_function.m_struct_size =
96       struct_layout->getSize()
97           .getQuantity(); // TODO Store m_struct_size as CharUnits
98   m_function.m_return_offset =
99       struct_layout->getFieldOffset(struct_layout->getFieldCount() - 1) / 8;
100   m_function.m_return_size =
101       struct_layout->getDataSize().getQuantity() - m_function.m_return_offset;
102 
103   for (unsigned field_index = 0, num_fields = struct_layout->getFieldCount();
104        field_index < num_fields; ++field_index) {
105     m_function.m_member_offsets.push_back(
106         struct_layout->getFieldOffset(field_index) / 8);
107   }
108 
109   m_function.m_struct_valid = true;
110 }
111 
112 void ASTStructExtractor::ExtractFromTopLevelDecl(Decl *D) {
113   LinkageSpecDecl *linkage_spec_decl = dyn_cast<LinkageSpecDecl>(D);
114 
115   if (linkage_spec_decl) {
116     RecordDecl::decl_iterator decl_iterator;
117 
118     for (decl_iterator = linkage_spec_decl->decls_begin();
119          decl_iterator != linkage_spec_decl->decls_end(); ++decl_iterator) {
120       ExtractFromTopLevelDecl(*decl_iterator);
121     }
122   }
123 
124   FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D);
125 
126   if (m_ast_context && function_decl &&
127       !m_function.m_wrapper_function_name.compare(
128           function_decl->getNameAsString().c_str())) {
129     ExtractFromFunctionDecl(function_decl);
130   }
131 }
132 
133 bool ASTStructExtractor::HandleTopLevelDecl(DeclGroupRef D) {
134   DeclGroupRef::iterator decl_iterator;
135 
136   for (decl_iterator = D.begin(); decl_iterator != D.end(); ++decl_iterator) {
137     Decl *decl = *decl_iterator;
138 
139     ExtractFromTopLevelDecl(decl);
140   }
141 
142   if (m_passthrough)
143     return m_passthrough->HandleTopLevelDecl(D);
144   return true;
145 }
146 
147 void ASTStructExtractor::HandleTranslationUnit(ASTContext &Ctx) {
148   if (m_passthrough)
149     m_passthrough->HandleTranslationUnit(Ctx);
150 }
151 
152 void ASTStructExtractor::HandleTagDeclDefinition(TagDecl *D) {
153   if (m_passthrough)
154     m_passthrough->HandleTagDeclDefinition(D);
155 }
156 
157 void ASTStructExtractor::CompleteTentativeDefinition(VarDecl *D) {
158   if (m_passthrough)
159     m_passthrough->CompleteTentativeDefinition(D);
160 }
161 
162 void ASTStructExtractor::HandleVTable(CXXRecordDecl *RD) {
163   if (m_passthrough)
164     m_passthrough->HandleVTable(RD);
165 }
166 
167 void ASTStructExtractor::PrintStats() {
168   if (m_passthrough)
169     m_passthrough->PrintStats();
170 }
171 
172 void ASTStructExtractor::InitializeSema(Sema &S) {
173   m_sema = &S;
174   m_action = reinterpret_cast<Action *>(m_sema);
175 
176   if (m_passthrough_sema)
177     m_passthrough_sema->InitializeSema(S);
178 }
179 
180 void ASTStructExtractor::ForgetSema() {
181   m_sema = NULL;
182   m_action = NULL;
183 
184   if (m_passthrough_sema)
185     m_passthrough_sema->ForgetSema();
186 }
187