//===---- CoverageMappingGen.h - Coverage mapping generation ----*- C++ -*-===//

//

// 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

//

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

//

// Instrumentation-based code coverage mapping generator

//

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

#ifndef LLVM_CLANG_LIB_CODEGEN_COVERAGEMAPPINGGEN_H

#define LLVM_CLANG_LIB_CODEGEN_COVERAGEMAPPINGGEN_H

#include "clang/Basic/LLVM.h"

#include "clang/Basic/SourceLocation.h"

#include "clang/Lex/PPCallbacks.h"

#include "clang/Lex/Preprocessor.h"

#include "llvm/ADT/DenseMap.h"

#include "llvm/IR/GlobalValue.h"

#include "llvm/Support/raw_ostream.h"

namespace clang {

class LangOptions;

class SourceManager;

class FileEntry;

class Preprocessor;

class Decl;

class Stmt;

struct SkippedRange {

  enum Kind {

    PPIfElse, // Preprocessor #if/#else ...

    EmptyLine,

    Comment,

  };

  SourceRange Range;

  // The location of token before the skipped source range.

  SourceLocation PrevTokLoc;

  // The location of token after the skipped source range.

  SourceLocation NextTokLoc;

  // The nature of this skipped range

  Kind RangeKind;

  bool isComment() { return RangeKind == Comment; }

  bool isEmptyLine() { return RangeKind == EmptyLine; }

  bool isPPIfElse() { return RangeKind == PPIfElse; }

  SkippedRange(SourceRange Range, Kind K,

               SourceLocation PrevTokLoc = SourceLocation(),

               SourceLocation NextTokLoc = SourceLocation())

      : Range(Range), PrevTokLoc(PrevTokLoc), NextTokLoc(NextTokLoc),

        RangeKind(K) {}

};

/// Stores additional source code information like skipped ranges which

/// is required by the coverage mapping generator and is obtained from

/// the preprocessor.

class CoverageSourceInfo : public PPCallbacks,

                           public CommentHandler,

                           public EmptylineHandler {

  // A vector of skipped source ranges and PrevTokLoc with NextTokLoc.

  std::vector<SkippedRange> SkippedRanges;

  SourceManager &SourceMgr;

public:

  // Location of the token parsed before HandleComment is called. This is

  // updated every time Preprocessor::Lex lexes a new token.

  SourceLocation PrevTokLoc;

  CoverageSourceInfo(SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}

  std::vector<SkippedRange> &getSkippedRanges() { return SkippedRanges; }

  void AddSkippedRange(SourceRange Range, SkippedRange::Kind RangeKind);

  void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override;

  void HandleEmptyline(SourceRange Range) override;

  bool HandleComment(Preprocessor &PP, SourceRange Range) override;

  void updateNextTokLoc(SourceLocation Loc);

};

namespace CodeGen {

class CodeGenModule;

/// Organizes the cross-function state that is used while generating

/// code coverage mapping data.

class CoverageMappingModuleGen {

  /// Information needed to emit a coverage record for a function.

  struct FunctionInfo {

    uint64_t NameHash;

    uint64_t FuncHash;

    std::string CoverageMapping;

    bool IsUsed;

  };

  CodeGenModule &CGM;

  CoverageSourceInfo &SourceInfo;

  llvm::SmallDenseMap<const FileEntry *, unsigned, 8> FileEntries;

  std::vector<llvm::Constant *> FunctionNames;

  std::vector<FunctionInfo> FunctionRecords;

  std::string getCurrentDirname();

  std::string normalizeFilename(StringRef Filename);

  /// Emit a function record.

  void emitFunctionMappingRecord(const FunctionInfo &Info,

                                 uint64_t FilenamesRef);

public:

  static CoverageSourceInfo *setUpCoverageCallbacks(Preprocessor &PP);

  CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo);

  CoverageSourceInfo &getSourceInfo() const {

    return SourceInfo;

  }

  /// Add a function's coverage mapping record to the collection of the

  /// function mapping records.

  void addFunctionMappingRecord(llvm::GlobalVariable *FunctionName,

                                StringRef FunctionNameValue,

                                uint64_t FunctionHash,

                                const std::string &CoverageMapping,

                                bool IsUsed = true);

  /// Emit the coverage mapping data for a translation unit.

  void emit();

  /// Return the coverage mapping translation unit file id

  /// for the given file.

  unsigned getFileID(const FileEntry *File);

  /// Return an interface into CodeGenModule.

  CodeGenModule &getCodeGenModule() { return CGM; }

};

/// Organizes the per-function state that is used while generating

/// code coverage mapping data.

class CoverageMappingGen {

  CoverageMappingModuleGen &CVM;

  SourceManager &SM;

  const LangOptions &LangOpts;

  llvm::DenseMap<const Stmt *, unsigned> *CounterMap;

public:

  CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,

                     const LangOptions &LangOpts)

      : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(nullptr) {}

  CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,

                     const LangOptions &LangOpts,

                     llvm::DenseMap<const Stmt *, unsigned> *CounterMap)

      : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(CounterMap) {}

  /// Emit the coverage mapping data which maps the regions of

  /// code to counters that will be used to find the execution

  /// counts for those regions.

  void emitCounterMapping(const Decl *D, llvm::raw_ostream &OS);

  /// Emit the coverage mapping data for an unused function.

  /// It creates mapping regions with the counter of zero.

  void emitEmptyMapping(const Decl *D, llvm::raw_ostream &OS);

};

} // end namespace CodeGen

} // end namespace clang

#endif