lldb/source/Plugins/ExpressionParser/Clang/ASTStructExtractor.cpp

   1 //===-- ASTStructExtractor.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 "ASTStructExtractor.h"
  10
  11 #include "lldb/Utility/Log.h"
  12 #include "clang/AST/ASTContext.h"
  13 #include "clang/AST/Decl.h"
  14 #include "clang/AST/DeclCXX.h"
  15 #include "clang/AST/DeclGroup.h"
  16 #include "clang/AST/Expr.h"
  17 #include "clang/AST/RecordLayout.h"
  18 #include "clang/AST/Stmt.h"
  19 #include "clang/Parse/Parser.h"
  20 #include "clang/Sema/Sema.h"
  21 #include "llvm/Support/Casting.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 #include <cstdlib>
  24
  25 using namespace llvm;
  26 using namespace clang;
  27 using namespace lldb_private;
  28
  29 ASTStructExtractor::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
  41 ASTStructExtractor::~ASTStructExtractor() = default;
  42
  43 void ASTStructExtractor::Initialize(ASTContext &Context) {
  44   m_ast_context = &Context;
  45
  46   if (m_passthrough)
  47     m_passthrough->Initialize(Context);
  48 }
  49
  50 void 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
 111 void 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
 132 bool 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
 146 void ASTStructExtractor::HandleTranslationUnit(ASTContext &Ctx) {
 147   if (m_passthrough)
 148     m_passthrough->HandleTranslationUnit(Ctx);
 149 }
 150
 151 void ASTStructExtractor::HandleTagDeclDefinition(TagDecl *D) {
 152   if (m_passthrough)
 153     m_passthrough->HandleTagDeclDefinition(D);
 154 }
 155
 156 void ASTStructExtractor::CompleteTentativeDefinition(VarDecl *D) {
 157   if (m_passthrough)
 158     m_passthrough->CompleteTentativeDefinition(D);
 159 }
 160
 161 void ASTStructExtractor::HandleVTable(CXXRecordDecl *RD) {
 162   if (m_passthrough)
 163     m_passthrough->HandleVTable(RD);
 164 }
 165
 166 void ASTStructExtractor::PrintStats() {
 167   if (m_passthrough)
 168     m_passthrough->PrintStats();
 169 }
 170
 171 void ASTStructExtractor::InitializeSema(Sema &S) {
 172   m_sema = &S;
 173
 174   if (m_passthrough_sema)
 175     m_passthrough_sema->InitializeSema(S);
 176 }
 177
 178 void ASTStructExtractor::ForgetSema() {
 179   m_sema = nullptr;
 180
 181   if (m_passthrough_sema)
 182     m_passthrough_sema->ForgetSema();
 183 }