//===- ControlFlowContext.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

//

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

//

//  This file defines a ControlFlowContext class that is used by dataflow

//  analyses that run over Control-Flow Graphs (CFGs).

//

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

#include "clang/Analysis/FlowSensitive/ControlFlowContext.h"

#include "clang/AST/ASTContext.h"

#include "clang/AST/Decl.h"

#include "clang/AST/Stmt.h"

#include "clang/Analysis/CFG.h"

#include "llvm/ADT/DenseMap.h"

#include "llvm/Support/Error.h"

#include <utility>

namespace clang {

namespace dataflow {

/// Returns a map from statements to basic blocks that contain them.

static llvm::DenseMap<const Stmt *, const CFGBlock *>

buildStmtToBasicBlockMap(const CFG &Cfg) {

  llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock;

  for (const CFGBlock *Block : Cfg) {

    if (Block == nullptr)

      continue;

    
for (const CFGElement &Element : *Block)1.63k
 {

      auto Stmt = Element.getAs<CFGStmt>();

      if (!Stmt)

        continue;

      StmtToBlock[Stmt.value().getStmt()] = Block;

    }

    if (const Stmt *TerminatorStmt = Block->getTerminatorStmt())

      StmtToBlock[TerminatorStmt] = Block;

  }

  return StmtToBlock;

}

llvm::Expected<ControlFlowContext>

ControlFlowContext::build(const Decl *D, Stmt *S, ASTContext *C) {

  CFG::BuildOptions Options;

  Options.PruneTriviallyFalseEdges = false;

  Options.AddImplicitDtors = true;

  Options.AddTemporaryDtors = true;

  Options.AddInitializers = true;

  Options.AddCXXDefaultInitExprInCtors = true;

  // Ensure that all sub-expressions in basic blocks are evaluated.

  Options.setAllAlwaysAdd();

  auto Cfg = CFG::buildCFG(D, S, C, Options);

  if (Cfg == nullptr)

    return llvm::createStringError(

        std::make_error_code(std::errc::invalid_argument),

        "CFG::buildCFG failed");

  llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock =

      buildStmtToBasicBlockMap(*Cfg);

  return ControlFlowContext(std::move(Cfg), std::move(StmtToBlock));

}

} // namespace dataflow

} // namespace clang