//===--- DiagnosticIDs.h - Diagnostic IDs Handling --------------*- 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

//

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

///

/// \file

/// Defines the Diagnostic IDs-related interfaces.

///

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

#ifndef LLVM_CLANG_BASIC_DIAGNOSTICIDS_H

#define LLVM_CLANG_BASIC_DIAGNOSTICIDS_H

#include "clang/Basic/LLVM.h"

#include "llvm/ADT/IntrusiveRefCntPtr.h"

#include "llvm/ADT/StringRef.h"

#include <optional>

#include <vector>

namespace clang {

  class DiagnosticsEngine;

  class SourceLocation;

  // Import the diagnostic enums themselves.

  namespace diag {

    enum class Group;

    // Size of each of the diagnostic categories.

    enum {

      DIAG_SIZE_COMMON        =  300,

      DIAG_SIZE_DRIVER        =  400,

      DIAG_SIZE_FRONTEND      =  150,

      DIAG_SIZE_SERIALIZATION =  120,

      DIAG_SIZE_LEX           =  400,

      DIAG_SIZE_PARSE         =  700,

      DIAG_SIZE_AST           =  300,

      DIAG_SIZE_COMMENT       =  100,

      DIAG_SIZE_CROSSTU       =  100,

      DIAG_SIZE_SEMA          = 4500,

      DIAG_SIZE_ANALYSIS      =  100,

      DIAG_SIZE_REFACTORING   = 1000,

    };

    // Start position for diagnostics.

    enum {

      DIAG_START_COMMON        =                          0,

      DIAG_START_DRIVER        = DIAG_START_COMMON        + static_cast<int>(DIAG_SIZE_COMMON),

      DIAG_START_FRONTEND      = DIAG_START_DRIVER        + static_cast<int>(DIAG_SIZE_DRIVER),

      DIAG_START_SERIALIZATION = DIAG_START_FRONTEND      + static_cast<int>(DIAG_SIZE_FRONTEND),

      DIAG_START_LEX           = DIAG_START_SERIALIZATION + static_cast<int>(DIAG_SIZE_SERIALIZATION),

      DIAG_START_PARSE         = DIAG_START_LEX           + static_cast<int>(DIAG_SIZE_LEX),

      DIAG_START_AST           = DIAG_START_PARSE         + static_cast<int>(DIAG_SIZE_PARSE),

      DIAG_START_COMMENT       = DIAG_START_AST           + static_cast<int>(DIAG_SIZE_AST),

      DIAG_START_CROSSTU       = DIAG_START_COMMENT       + static_cast<int>(DIAG_SIZE_COMMENT),

      DIAG_START_SEMA          = DIAG_START_CROSSTU       + static_cast<int>(DIAG_SIZE_CROSSTU),

      DIAG_START_ANALYSIS      = DIAG_START_SEMA          + static_cast<int>(DIAG_SIZE_SEMA),

      DIAG_START_REFACTORING   = DIAG_START_ANALYSIS      + static_cast<int>(DIAG_SIZE_ANALYSIS),

      DIAG_UPPER_LIMIT         = DIAG_START_REFACTORING   + static_cast<int>(DIAG_SIZE_REFACTORING)

    };

    class CustomDiagInfo;

    /// All of the diagnostics that can be emitted by the frontend.

    typedef unsigned kind;

    // Get typedefs for common diagnostics.

    enum {

#define DIAG(ENUM, FLAGS, DEFAULT_MAPPING, DESC, GROUP, SFINAE, CATEGORY,      \

             NOWERROR, SHOWINSYSHEADER, SHOWINSYSMACRO, DEFFERABLE)            \

  ENUM,

#define COMMONSTART

#include "clang/Basic/DiagnosticCommonKinds.inc"

      NUM_BUILTIN_COMMON_DIAGNOSTICS

#undef DIAG

    };

    /// Enum values that allow the client to map NOTEs, WARNINGs, and EXTENSIONs

    /// to either Ignore (nothing), Remark (emit a remark), Warning

    /// (emit a warning) or Error (emit as an error).  It allows clients to

    /// map ERRORs to Error or Fatal (stop emitting diagnostics after this one).

    enum class Severity {

      // NOTE: 0 means "uncomputed".

      Ignored = 1, ///< Do not present this diagnostic, ignore it.

      Remark = 2,  ///< Present this diagnostic as a remark.

      Warning = 3, ///< Present this diagnostic as a warning.

      Error = 4,   ///< Present this diagnostic as an error.

      Fatal = 5    ///< Present this diagnostic as a fatal error.

    };

    /// Flavors of diagnostics we can emit. Used to filter for a particular

    /// kind of diagnostic (for instance, for -W/-R flags).

    enum class Flavor {

      WarningOrError, ///< A diagnostic that indicates a problem or potential

                      ///< problem. Can be made fatal by -Werror.

      Remark          ///< A diagnostic that indicates normal progress through

                      ///< compilation.

    };

  }

class DiagnosticMapping {

  LLVM_PREFERRED_TYPE(diag::Severity)

  unsigned Severity : 3;

  LLVM_PREFERRED_TYPE(bool)

  unsigned IsUser : 1;

  LLVM_PREFERRED_TYPE(bool)

  unsigned IsPragma : 1;

  LLVM_PREFERRED_TYPE(bool)

  unsigned HasNoWarningAsError : 1;

  LLVM_PREFERRED_TYPE(bool)

  unsigned HasNoErrorAsFatal : 1;

  LLVM_PREFERRED_TYPE(bool)

  unsigned WasUpgradedFromWarning : 1;

public:

  static DiagnosticMapping Make(diag::Severity Severity, bool IsUser,

                                bool IsPragma) {

    DiagnosticMapping Result;

    Result.Severity = (unsigned)Severity;

    Result.IsUser = IsUser;

    Result.IsPragma = IsPragma;

    Result.HasNoWarningAsError = 0;

    Result.HasNoErrorAsFatal = 0;

    Result.WasUpgradedFromWarning = 0;

    return Result;

  }

  diag::Severity getSeverity() const { return (diag::Severity)Severity; }

  void setSeverity(diag::Severity Value) { Severity = (unsigned)Value; }

  bool isUser() const { return IsUser; }

  bool isPragma() const { return IsPragma; }

  bool isErrorOrFatal() const {

    return getSeverity() == diag::Severity::Error ||

           getSeverity() == diag::Severity::Fatal;

  }

  bool hasNoWarningAsError() const { return HasNoWarningAsError; }

  void setNoWarningAsError(bool Value) { HasNoWarningAsError = Value; }

  bool hasNoErrorAsFatal() const { return HasNoErrorAsFatal; }

  void setNoErrorAsFatal(bool Value) { HasNoErrorAsFatal = Value; }

  /// Whether this mapping attempted to map the diagnostic to a warning, but

  /// was overruled because the diagnostic was already mapped to an error or

  /// fatal error.

  bool wasUpgradedFromWarning() const { return WasUpgradedFromWarning; }

  void setUpgradedFromWarning(bool Value) { WasUpgradedFromWarning = Value; }

  /// Serialize this mapping as a raw integer.

  unsigned serialize() const {

    return (IsUser << 7) | (IsPragma << 6) | (HasNoWarningAsError << 5) |

           (HasNoErrorAsFatal << 4) | (WasUpgradedFromWarning << 3) | Severity;

  }

  /// Deserialize a mapping.

  static DiagnosticMapping deserialize(unsigned Bits) {

    DiagnosticMapping Result;

    Result.IsUser = (Bits >> 7) & 1;

    Result.IsPragma = (Bits >> 6) & 1;

    Result.HasNoWarningAsError = (Bits >> 5) & 1;

    Result.HasNoErrorAsFatal = (Bits >> 4) & 1;

    Result.WasUpgradedFromWarning = (Bits >> 3) & 1;

    Result.Severity = Bits & 0x7;

    return Result;

  }

  bool operator==(DiagnosticMapping Other) const {

    return serialize() == Other.serialize();

  }

};

/// Used for handling and querying diagnostic IDs.

///

/// Can be used and shared by multiple Diagnostics for multiple translation units.

class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {

public:

  /// The level of the diagnostic, after it has been through mapping.

  enum Level {

    Ignored, Note, Remark, Warning, Error, Fatal

  };

private:

  /// Information for uniquing and looking up custom diags.

  std::unique_ptr<diag::CustomDiagInfo> CustomDiagInfo;

public:

  DiagnosticIDs();

  ~DiagnosticIDs();

  /// Return an ID for a diagnostic with the specified format string and

  /// level.

  ///

  /// If this is the first request for this diagnostic, it is registered and

  /// created, otherwise the existing ID is returned.

  // FIXME: Replace this function with a create-only facilty like

  // createCustomDiagIDFromFormatString() to enforce safe usage. At the time of

  // writing, nearly all callers of this function were invalid.

  unsigned getCustomDiagID(Level L, StringRef FormatString);

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

  // Diagnostic classification and reporting interfaces.

  //

  /// Given a diagnostic ID, return a description of the issue.

  StringRef getDescription(unsigned DiagID) const;

  /// Return true if the unmapped diagnostic levelof the specified

  /// diagnostic ID is a Warning or Extension.

  ///

  /// This only works on builtin diagnostics, not custom ones, and is not

  /// legal to call on NOTEs.

  static bool isBuiltinWarningOrExtension(unsigned DiagID);

  /// Return true if the specified diagnostic is mapped to errors by

  /// default.

  static bool isDefaultMappingAsError(unsigned DiagID);

  /// Get the default mapping for this diagnostic.

  static DiagnosticMapping getDefaultMapping(unsigned DiagID);

  /// Determine whether the given built-in diagnostic ID is a Note.

  static bool isBuiltinNote(unsigned DiagID);

  /// Determine whether the given built-in diagnostic ID is for an

  /// extension of some sort.

  static bool isBuiltinExtensionDiag(unsigned DiagID) {

    bool ignored;

    return isBuiltinExtensionDiag(DiagID, ignored);

  }

  /// Determine whether the given built-in diagnostic ID is for an

  /// extension of some sort, and whether it is enabled by default.

  ///

  /// This also returns EnabledByDefault, which is set to indicate whether the

  /// diagnostic is ignored by default (in which case -pedantic enables it) or

  /// treated as a warning/error by default.

  ///

  static bool isBuiltinExtensionDiag(unsigned DiagID, bool &EnabledByDefault);

  /// Given a group ID, returns the flag that toggles the group.

  /// For example, for Group::DeprecatedDeclarations, returns

  /// "deprecated-declarations".

  static StringRef getWarningOptionForGroup(diag::Group);

  /// Given a diagnostic group ID, return its documentation.

  static StringRef getWarningOptionDocumentation(diag::Group GroupID);

  /// Given a group ID, returns the flag that toggles the group.

  /// For example, for "deprecated-declarations", returns

  /// Group::DeprecatedDeclarations.

  static std::optional<diag::Group> getGroupForWarningOption(StringRef);

  /// Return the lowest-level group that contains the specified diagnostic.

  static std::optional<diag::Group> getGroupForDiag(unsigned DiagID);

  /// Return the lowest-level warning option that enables the specified

  /// diagnostic.

  ///

  /// If there is no -Wfoo flag that controls the diagnostic, this returns null.

  static StringRef getWarningOptionForDiag(unsigned DiagID);

  /// Return the category number that a specified \p DiagID belongs to,

  /// or 0 if no category.

  static unsigned getCategoryNumberForDiag(unsigned DiagID);

  /// Return the number of diagnostic categories.

  static unsigned getNumberOfCategories();

  /// Given a category ID, return the name of the category.

  static StringRef getCategoryNameFromID(unsigned CategoryID);

  /// Return true if a given diagnostic falls into an ARC diagnostic

  /// category.

  static bool isARCDiagnostic(unsigned DiagID);

  /// Enumeration describing how the emission of a diagnostic should

  /// be treated when it occurs during C++ template argument deduction.

  enum SFINAEResponse {

    /// The diagnostic should not be reported, but it should cause

    /// template argument deduction to fail.

    ///

    /// The vast majority of errors that occur during template argument

    /// deduction fall into this category.

    SFINAE_SubstitutionFailure,

    /// The diagnostic should be suppressed entirely.

    ///

    /// Warnings generally fall into this category.

    SFINAE_Suppress,

    /// The diagnostic should be reported.

    ///

    /// The diagnostic should be reported. Various fatal errors (e.g.,

    /// template instantiation depth exceeded) fall into this category.

    SFINAE_Report,

    /// The diagnostic is an access-control diagnostic, which will be

    /// substitution failures in some contexts and reported in others.

    SFINAE_AccessControl

  };

  /// Determines whether the given built-in diagnostic ID is

  /// for an error that is suppressed if it occurs during C++ template

  /// argument deduction.

  ///

  /// When an error is suppressed due to SFINAE, the template argument

  /// deduction fails but no diagnostic is emitted. Certain classes of

  /// errors, such as those errors that involve C++ access control,

  /// are not SFINAE errors.

  static SFINAEResponse getDiagnosticSFINAEResponse(unsigned DiagID);

  /// Whether the diagnostic message can be deferred.

  ///

  /// For single source offloading languages, a diagnostic message occurred

  /// in a device host function may be deferred until the function is sure

  /// to be emitted.

  static bool isDeferrable(unsigned DiagID);

  /// Get the string of all diagnostic flags.

  ///

  /// \returns A list of all diagnostics flags as they would be written in a

  /// command line invocation including their `no-` variants. For example:

  /// `{"-Wempty-body", "-Wno-empty-body", ...}`

  static std::vector<std::string> getDiagnosticFlags();

  /// Get the set of all diagnostic IDs in the group with the given name.

  ///

  /// \param[out] Diags - On return, the diagnostics in the group.

  /// \returns \c true if the given group is unknown, \c false otherwise.

  bool getDiagnosticsInGroup(diag::Flavor Flavor, StringRef Group,

                             SmallVectorImpl<diag::kind> &Diags) const;

  /// Get the set of all diagnostic IDs.

  static void getAllDiagnostics(diag::Flavor Flavor,

                                std::vector<diag::kind> &Diags);

  /// Get the diagnostic option with the closest edit distance to the

  /// given group name.

  static StringRef getNearestOption(diag::Flavor Flavor, StringRef Group);

private:

  /// Classify the specified diagnostic ID into a Level, consumable by

  /// the DiagnosticClient.

  ///

  /// The classification is based on the way the client configured the

  /// DiagnosticsEngine object.

  ///

  /// \param Loc The source location for which we are interested in finding out

  /// the diagnostic state. Can be null in order to query the latest state.

  DiagnosticIDs::Level

  getDiagnosticLevel(unsigned DiagID, SourceLocation Loc,

                     const DiagnosticsEngine &Diag) const LLVM_READONLY;

  diag::Severity

  getDiagnosticSeverity(unsigned DiagID, SourceLocation Loc,

                        const DiagnosticsEngine &Diag) const LLVM_READONLY;

  /// Used to report a diagnostic that is finally fully formed.

  ///

  /// \returns \c true if the diagnostic was emitted, \c false if it was

  /// suppressed.

  bool ProcessDiag(DiagnosticsEngine &Diag) const;

  /// Used to emit a diagnostic that is finally fully formed,

  /// ignoring suppression.

  void EmitDiag(DiagnosticsEngine &Diag, Level DiagLevel) const;

  /// Whether the diagnostic may leave the AST in a state where some

  /// invariants can break.

  bool isUnrecoverable(unsigned DiagID) const;

  friend class DiagnosticsEngine;

};

}  // end namespace clang

#endif