//===-- ASTStructExtractor.cpp --------------------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "ASTStructExtractor.h"

#include "lldb/Utility/Log.h"

#include "clang/AST/ASTContext.h"

#include "clang/AST/Decl.h"

#include "clang/AST/DeclCXX.h"

#include "clang/AST/DeclGroup.h"

#include "clang/AST/Expr.h"

#include "clang/AST/RecordLayout.h"

#include "clang/AST/Stmt.h"

#include "clang/Parse/Parser.h"

#include "clang/Sema/Sema.h"

#include "llvm/Support/Casting.h"

#include "llvm/Support/raw_ostream.h"

#include <cstdlib>

using namespace llvm;

using namespace clang;

using namespace lldb_private;

ASTStructExtractor::ASTStructExtractor(ASTConsumer *passthrough,

                                       const char *struct_name,

                                       ClangFunctionCaller &function)

    : m_ast_context(nullptr), m_passthrough(passthrough),

      m_passthrough_sema(nullptr), m_sema(nullptr), m_function(function),

      m_struct_name(struct_name) {

  if (!m_passthrough)

    return;

  m_passthrough_sema = dyn_cast<SemaConsumer>(passthrough);

}

ASTStructExtractor::~ASTStructExtractor() = default;

void ASTStructExtractor::Initialize(ASTContext &Context) {

  m_ast_context = &Context;

  if (m_passthrough)

    m_passthrough->Initialize(Context);

}

void ASTStructExtractor::ExtractFromFunctionDecl(FunctionDecl *F) {

  if (!F->hasBody())

    return;

  Stmt *body_stmt = F->getBody();

  CompoundStmt *body_compound_stmt = dyn_cast<CompoundStmt>(body_stmt);

  if (!body_compound_stmt)

    return; // do we have to handle this?

  RecordDecl *struct_decl = nullptr;

  StringRef desired_name(m_struct_name);

  for (CompoundStmt::const_body_iterator bi = body_compound_stmt->body_begin(),

                                         be = body_compound_stmt->body_end();

       bi != be; 
++bi0
) {

    Stmt *curr_stmt = *bi;

    DeclStmt *curr_decl_stmt = dyn_cast<DeclStmt>(curr_stmt);

    if (!curr_decl_stmt)

      continue;

    DeclGroupRef decl_group = curr_decl_stmt->getDeclGroup();

    for (Decl *candidate_decl : decl_group) {

      RecordDecl *candidate_record_decl = dyn_cast<RecordDecl>(candidate_decl);

      if (!candidate_record_decl)

        continue;

      if (candidate_record_decl->getName() == desired_name) {

        struct_decl = candidate_record_decl;

        break;

      }

    }

    if (struct_decl)

      break;

  }

  if (!struct_decl)

    return;

  const ASTRecordLayout *struct_layout(

      &m_ast_context->getASTRecordLayout(struct_decl));

  if (!struct_layout)

    return;

  m_function.m_struct_size =

      struct_layout->getSize()

          .getQuantity(); // TODO Store m_struct_size as CharUnits

  m_function.m_return_offset =

      struct_layout->getFieldOffset(struct_layout->getFieldCount() - 1) / 8;

  m_function.m_return_size =

      struct_layout->getDataSize().getQuantity() - m_function.m_return_offset;

  for (unsigned field_index = 0, num_fields = struct_layout->getFieldCount();

       field_index < num_fields; 
++field_index13.6k
) {

    m_function.m_member_offsets.push_back(

        struct_layout->getFieldOffset(field_index) / 8);

  }

  m_function.m_struct_valid = true;

}

void ASTStructExtractor::ExtractFromTopLevelDecl(Decl *D) {

  LinkageSpecDecl *linkage_spec_decl = dyn_cast<LinkageSpecDecl>(D);

  if (linkage_spec_decl) {

    RecordDecl::decl_iterator decl_iterator;

    for (decl_iterator = linkage_spec_decl->decls_begin();

         decl_iterator != linkage_spec_decl->decls_end(); 
++decl_iterator2.00k
) {

      ExtractFromTopLevelDecl(*decl_iterator);

    }

  }

  FunctionDecl *function_decl = dyn_cast<FunctionDecl>(D);

  if (m_ast_context && function_decl &&

      !m_function.m_wrapper_function_name.compare(

          function_decl->getNameAsString())) {

    ExtractFromFunctionDecl(function_decl);

  }

}

bool ASTStructExtractor::HandleTopLevelDecl(DeclGroupRef D) {

  DeclGroupRef::iterator decl_iterator;

  for (decl_iterator = D.begin(); decl_iterator != D.end(); 
++decl_iterator2.00k
) {

    Decl *decl = *decl_iterator;

    ExtractFromTopLevelDecl(decl);

  }

  if (m_passthrough)

    return m_passthrough->HandleTopLevelDecl(D);

  return true;

}

void ASTStructExtractor::HandleTranslationUnit(ASTContext &Ctx) {

  if (m_passthrough)

    m_passthrough->HandleTranslationUnit(Ctx);

}

void ASTStructExtractor::HandleTagDeclDefinition(TagDecl *D) {

  if (m_passthrough)

    m_passthrough->HandleTagDeclDefinition(D);

}

void ASTStructExtractor::CompleteTentativeDefinition(VarDecl *D) {

  if (m_passthrough)

    m_passthrough->CompleteTentativeDefinition(D);

}

void ASTStructExtractor::HandleVTable(CXXRecordDecl *RD) {

  if (m_passthrough)

    m_passthrough->HandleVTable(RD);

}

void ASTStructExtractor::PrintStats() {

  if (m_passthrough)

    m_passthrough->PrintStats();

}

void ASTStructExtractor::InitializeSema(Sema &S) {

  m_sema = &S;

  if (m_passthrough_sema)

    m_passthrough_sema->InitializeSema(S);

}

void ASTStructExtractor::ForgetSema() {

  m_sema = nullptr;

  if (m_passthrough_sema)

    m_passthrough_sema->ForgetSema();

}