xref: /external/clang/include/clang/Basic/Diagnostic.h

//===--- Diagnostic.h - C Language Family Diagnostic Handling ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Defines the Diagnostic-related interfaces.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_DIAGNOSTIC_H
#define LLVM_CLANG_DIAGNOSTIC_H

#include "clang/Basic/DiagnosticIDs.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/iterator_range.h"
#include <list>
#include <vector>

namespace clang {
  class DeclContext;
  class DiagnosticBuilder;
  class DiagnosticConsumer;
  class DiagnosticErrorTrap;
  class DiagnosticOptions;
  class IdentifierInfo;
  class LangOptions;
  class Preprocessor;
  class StoredDiagnostic;
  namespace tok {
  enum TokenKind : unsigned short;
  }

/// \brief Annotates a diagnostic with some code that should be
/// inserted, removed, or replaced to fix the problem.
///
/// This kind of hint should be used when we are certain that the
/// introduction, removal, or modification of a particular (small!)
/// amount of code will correct a compilation error. The compiler
/// should also provide full recovery from such errors, such that
/// suppressing the diagnostic output can still result in successful
/// compilation.
class FixItHint {
public:
  /// \brief Code that should be replaced to correct the error. Empty for an
  /// insertion hint.
  CharSourceRange RemoveRange;

  /// \brief Code in the specific range that should be inserted in the insertion
  /// location.
  CharSourceRange InsertFromRange;

  /// \brief The actual code to insert at the insertion location, as a
  /// string.
  std::string CodeToInsert;

  bool BeforePreviousInsertions;

  /// \brief Empty code modification hint, indicating that no code
  /// modification is known.
  FixItHint() : BeforePreviousInsertions(false) { }

  bool isNull() const {
    return !RemoveRange.isValid();
  }

  /// \brief Create a code modification hint that inserts the given
  /// code string at a specific location.
  static FixItHint CreateInsertion(SourceLocation InsertionLoc,
                                   StringRef Code,
                                   bool BeforePreviousInsertions = false) {
    FixItHint Hint;
    Hint.RemoveRange =
      CharSourceRange::getCharRange(InsertionLoc, InsertionLoc);
    Hint.CodeToInsert = Code;
    Hint.BeforePreviousInsertions = BeforePreviousInsertions;
    return Hint;
  }

  /// \brief Create a code modification hint that inserts the given
  /// code from \p FromRange at a specific location.
  static FixItHint CreateInsertionFromRange(SourceLocation InsertionLoc,
                                            CharSourceRange FromRange,
                                        bool BeforePreviousInsertions = false) {
    FixItHint Hint;
    Hint.RemoveRange =
      CharSourceRange::getCharRange(InsertionLoc, InsertionLoc);
    Hint.InsertFromRange = FromRange;
    Hint.BeforePreviousInsertions = BeforePreviousInsertions;
    return Hint;
  }

  /// \brief Create a code modification hint that removes the given
  /// source range.
  static FixItHint CreateRemoval(CharSourceRange RemoveRange) {
    FixItHint Hint;
    Hint.RemoveRange = RemoveRange;
    return Hint;
  }
  static FixItHint CreateRemoval(SourceRange RemoveRange) {
    return CreateRemoval(CharSourceRange::getTokenRange(RemoveRange));
  }

  /// \brief Create a code modification hint that replaces the given
  /// source range with the given code string.
  static FixItHint CreateReplacement(CharSourceRange RemoveRange,
                                     StringRef Code) {
    FixItHint Hint;
    Hint.RemoveRange = RemoveRange;
    Hint.CodeToInsert = Code;
    return Hint;
  }

  static FixItHint CreateReplacement(SourceRange RemoveRange,
                                     StringRef Code) {
    return CreateReplacement(CharSourceRange::getTokenRange(RemoveRange), Code);
  }
};

/// \brief Concrete class used by the front-end to report problems and issues.
///
/// This massages the diagnostics (e.g. handling things like "report warnings
/// as errors" and passes them off to the DiagnosticConsumer for reporting to
/// the user. DiagnosticsEngine is tied to one translation unit and one
/// SourceManager.
class DiagnosticsEngine : public RefCountedBase<DiagnosticsEngine> {
  DiagnosticsEngine(const DiagnosticsEngine &) LLVM_DELETED_FUNCTION;
  void operator=(const DiagnosticsEngine &) LLVM_DELETED_FUNCTION;

public:
  /// \brief The level of the diagnostic, after it has been through mapping.
  enum Level {
    Ignored = DiagnosticIDs::Ignored,
    Note = DiagnosticIDs::Note,
    Remark = DiagnosticIDs::Remark,
    Warning = DiagnosticIDs::Warning,
    Error = DiagnosticIDs::Error,
    Fatal = DiagnosticIDs::Fatal
  };

  enum ArgumentKind {
    ak_std_string,      ///< std::string
    ak_c_string,        ///< const char *
    ak_sint,            ///< int
    ak_uint,            ///< unsigned
    ak_tokenkind,       ///< enum TokenKind : unsigned
    ak_identifierinfo,  ///< IdentifierInfo
    ak_qualtype,        ///< QualType
    ak_declarationname, ///< DeclarationName
    ak_nameddecl,       ///< NamedDecl *
    ak_nestednamespec,  ///< NestedNameSpecifier *
    ak_declcontext,     ///< DeclContext *
    ak_qualtype_pair,   ///< pair<QualType, QualType>
    ak_attr             ///< Attr *
  };

  /// \brief Represents on argument value, which is a union discriminated
  /// by ArgumentKind, with a value.
  typedef std::pair<ArgumentKind, intptr_t> ArgumentValue;

private:
  unsigned char AllExtensionsSilenced; // Used by __extension__
  bool IgnoreAllWarnings;        // Ignore all warnings: -w
  bool WarningsAsErrors;         // Treat warnings like errors.
  bool EnableAllWarnings;        // Enable all warnings.
  bool ErrorsAsFatal;            // Treat errors like fatal errors.
  bool SuppressSystemWarnings;   // Suppress warnings in system headers.
  bool SuppressAllDiagnostics;   // Suppress all diagnostics.
  bool ElideType;                // Elide common types of templates.
  bool PrintTemplateTree;        // Print a tree when comparing templates.
  bool ShowColors;               // Color printing is enabled.
  OverloadsShown ShowOverloads;  // Which overload candidates to show.
  unsigned ErrorLimit;           // Cap of # errors emitted, 0 -> no limit.
  unsigned TemplateBacktraceLimit; // Cap on depth of template backtrace stack,
                                   // 0 -> no limit.
  unsigned ConstexprBacktraceLimit; // Cap on depth of constexpr evaluation
                                    // backtrace stack, 0 -> no limit.
  diag::Severity ExtBehavior;       // Map extensions to warnings or errors?
  IntrusiveRefCntPtr<DiagnosticIDs> Diags;
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts;
  DiagnosticConsumer *Client;
  bool OwnsDiagClient;
  SourceManager *SourceMgr;

  /// \brief Mapping information for diagnostics.
  ///
  /// Mapping info is packed into four bits per diagnostic.  The low three
  /// bits are the mapping (an instance of diag::Severity), or zero if unset.
  /// The high bit is set when the mapping was established as a user mapping.
  /// If the high bit is clear, then the low bits are set to the default
  /// value, and should be mapped with -pedantic, -Werror, etc.
  ///
  /// A new DiagState is created and kept around when diagnostic pragmas modify
  /// the state so that we know what is the diagnostic state at any given
  /// source location.
  class DiagState {
    llvm::DenseMap<unsigned, DiagnosticMapping> DiagMap;

  public:
    typedef llvm::DenseMap<unsigned, DiagnosticMapping>::iterator iterator;
    typedef llvm::DenseMap<unsigned, DiagnosticMapping>::const_iterator
    const_iterator;

    void setMapping(diag::kind Diag, DiagnosticMapping Info) {
      DiagMap[Diag] = Info;
    }

    DiagnosticMapping &getOrAddMapping(diag::kind Diag);

    const_iterator begin() const { return DiagMap.begin(); }
    const_iterator end() const { return DiagMap.end(); }
  };

  /// \brief Keeps and automatically disposes all DiagStates that we create.
  std::list<DiagState> DiagStates;

  /// \brief Represents a point in source where the diagnostic state was
  /// modified because of a pragma.
  ///
  /// 'Loc' can be null if the point represents the diagnostic state
  /// modifications done through the command-line.
  struct DiagStatePoint {
    DiagState *State;
    FullSourceLoc Loc;
    DiagStatePoint(DiagState *State, FullSourceLoc Loc)
      : State(State), Loc(Loc) { }

    bool operator<(const DiagStatePoint &RHS) const {
      // If Loc is invalid it means it came from <command-line>, in which case
      // we regard it as coming before any valid source location.
      if (RHS.Loc.isInvalid())
        return false;
      if (Loc.isInvalid())
        return true;
      return Loc.isBeforeInTranslationUnitThan(RHS.Loc);
    }
  };

  /// \brief A sorted vector of all DiagStatePoints representing changes in
  /// diagnostic state due to diagnostic pragmas.
  ///
  /// The vector is always sorted according to the SourceLocation of the
  /// DiagStatePoint.
  typedef std::vector<DiagStatePoint> DiagStatePointsTy;
  mutable DiagStatePointsTy DiagStatePoints;

  /// \brief Keeps the DiagState that was active during each diagnostic 'push'
  /// so we can get back at it when we 'pop'.
  std::vector<DiagState *> DiagStateOnPushStack;

  DiagState *GetCurDiagState() const {
    assert(!DiagStatePoints.empty());
    return DiagStatePoints.back().State;
  }

  void PushDiagStatePoint(DiagState *State, SourceLocation L) {
    FullSourceLoc Loc(L, getSourceManager());
    // Make sure that DiagStatePoints is always sorted according to Loc.
    assert(Loc.isValid() && "Adding invalid loc point");
    assert(!DiagStatePoints.empty() &&
           (DiagStatePoints.back().Loc.isInvalid() ||
            DiagStatePoints.back().Loc.isBeforeInTranslationUnitThan(Loc)) &&
           "Previous point loc comes after or is the same as new one");
    DiagStatePoints.push_back(DiagStatePoint(State, Loc));
  }

  /// \brief Finds the DiagStatePoint that contains the diagnostic state of
  /// the given source location.
  DiagStatePointsTy::iterator GetDiagStatePointForLoc(SourceLocation Loc) const;

  /// \brief Sticky flag set to \c true when an error is emitted.
  bool ErrorOccurred;

  /// \brief Sticky flag set to \c true when an "uncompilable error" occurs.
  /// I.e. an error that was not upgraded from a warning by -Werror.
  bool UncompilableErrorOccurred;

  /// \brief Sticky flag set to \c true when a fatal error is emitted.
  bool FatalErrorOccurred;

  /// \brief Indicates that an unrecoverable error has occurred.
  bool UnrecoverableErrorOccurred;

  /// \brief Counts for DiagnosticErrorTrap to check whether an error occurred
  /// during a parsing section, e.g. during parsing a function.
  unsigned TrapNumErrorsOccurred;
  unsigned TrapNumUnrecoverableErrorsOccurred;

  /// \brief The level of the last diagnostic emitted.
  ///
  /// This is used to emit continuation diagnostics with the same level as the
  /// diagnostic that they follow.
  DiagnosticIDs::Level LastDiagLevel;

  unsigned NumWarnings;         ///< Number of warnings reported
  unsigned NumErrors;           ///< Number of errors reported
  unsigned NumErrorsSuppressed; ///< Number of errors suppressed

  /// \brief A function pointer that converts an opaque diagnostic
  /// argument to a strings.
  ///
  /// This takes the modifiers and argument that was present in the diagnostic.
  ///
  /// The PrevArgs array indicates the previous arguments formatted for this
  /// diagnostic.  Implementations of this function can use this information to
  /// avoid redundancy across arguments.
  ///
  /// This is a hack to avoid a layering violation between libbasic and libsema.
  typedef void (*ArgToStringFnTy)(
      ArgumentKind Kind, intptr_t Val,
      StringRef Modifier, StringRef Argument,
      ArrayRef<ArgumentValue> PrevArgs,
      SmallVectorImpl<char> &Output,
      void *Cookie,
      ArrayRef<intptr_t> QualTypeVals);
  void *ArgToStringCookie;
  ArgToStringFnTy ArgToStringFn;

  /// \brief ID of the "delayed" diagnostic, which is a (typically
  /// fatal) diagnostic that had to be delayed because it was found
  /// while emitting another diagnostic.
  unsigned DelayedDiagID;

  /// \brief First string argument for the delayed diagnostic.
  std::string DelayedDiagArg1;

  /// \brief Second string argument for the delayed diagnostic.
  std::string DelayedDiagArg2;

  /// \brief Optional flag value.
  ///
  /// Some flags accept values, for instance: -Wframe-larger-than=<value> and
  /// -Rpass=<value>. The content of this string is emitted after the flag name
  /// and '='.
  std::string FlagValue;

public:
  explicit DiagnosticsEngine(
                      const IntrusiveRefCntPtr<DiagnosticIDs> &Diags,
                      DiagnosticOptions *DiagOpts,
                      DiagnosticConsumer *client = nullptr,
                      bool ShouldOwnClient = true);
  ~DiagnosticsEngine();

  const IntrusiveRefCntPtr<DiagnosticIDs> &getDiagnosticIDs() const {
    return Diags;
  }

  /// \brief Retrieve the diagnostic options.
  DiagnosticOptions &getDiagnosticOptions() const { return *DiagOpts; }

  typedef llvm::iterator_range<DiagState::const_iterator> diag_mapping_range;

  /// \brief Get the current set of diagnostic mappings.
  diag_mapping_range getDiagnosticMappings() const {
    const DiagState &DS = *GetCurDiagState();
    return diag_mapping_range(DS.begin(), DS.end());
  }

  DiagnosticConsumer *getClient() { return Client; }
  const DiagnosticConsumer *getClient() const { return Client; }

  /// \brief Determine whether this \c DiagnosticsEngine object own its client.
  bool ownsClient() const { return OwnsDiagClient; }

  /// \brief Return the current diagnostic client along with ownership of that
  /// client.
  DiagnosticConsumer *takeClient() {
    OwnsDiagClient = false;
    return Client;
  }

  bool hasSourceManager() const { return SourceMgr != nullptr; }
  SourceManager &getSourceManager() const {
    assert(SourceMgr && "SourceManager not set!");
    return *SourceMgr;
  }
  void setSourceManager(SourceManager *SrcMgr) { SourceMgr = SrcMgr; }

  //===--------------------------------------------------------------------===//
  //  DiagnosticsEngine characterization methods, used by a client to customize
  //  how diagnostics are emitted.
  //

  /// \brief Copies the current DiagMappings and pushes the new copy
  /// onto the top of the stack.
  void pushMappings(SourceLocation Loc);

  /// \brief Pops the current DiagMappings off the top of the stack,
  /// causing the new top of the stack to be the active mappings.
  ///
  /// \returns \c true if the pop happens, \c false if there is only one
  /// DiagMapping on the stack.
  bool popMappings(SourceLocation Loc);

  /// \brief Set the diagnostic client associated with this diagnostic object.
  ///
  /// \param ShouldOwnClient true if the diagnostic object should take
  /// ownership of \c client.
  void setClient(DiagnosticConsumer *client, bool ShouldOwnClient = true);

  /// \brief Specify a limit for the number of errors we should
  /// emit before giving up.
  ///
  /// Zero disables the limit.
  void setErrorLimit(unsigned Limit) { ErrorLimit = Limit; }

  /// \brief Specify the maximum number of template instantiation
  /// notes to emit along with a given diagnostic.
  void setTemplateBacktraceLimit(unsigned Limit) {
    TemplateBacktraceLimit = Limit;
  }

  /// \brief Retrieve the maximum number of template instantiation
  /// notes to emit along with a given diagnostic.
  unsigned getTemplateBacktraceLimit() const {
    return TemplateBacktraceLimit;
  }

  /// \brief Specify the maximum number of constexpr evaluation
  /// notes to emit along with a given diagnostic.
  void setConstexprBacktraceLimit(unsigned Limit) {
    ConstexprBacktraceLimit = Limit;
  }

  /// \brief Retrieve the maximum number of constexpr evaluation
  /// notes to emit along with a given diagnostic.
  unsigned getConstexprBacktraceLimit() const {
    return ConstexprBacktraceLimit;
  }

  /// \brief When set to true, any unmapped warnings are ignored.
  ///
  /// If this and WarningsAsErrors are both set, then this one wins.
  void setIgnoreAllWarnings(bool Val) { IgnoreAllWarnings = Val; }
  bool getIgnoreAllWarnings() const { return IgnoreAllWarnings; }

  /// \brief When set to true, any unmapped ignored warnings are no longer
  /// ignored.
  ///
  /// If this and IgnoreAllWarnings are both set, then that one wins.
  void setEnableAllWarnings(bool Val) { EnableAllWarnings = Val; }
  bool getEnableAllWarnings() const { return EnableAllWarnings; }

  /// \brief When set to true, any warnings reported are issued as errors.
  void setWarningsAsErrors(bool Val) { WarningsAsErrors = Val; }
  bool getWarningsAsErrors() const { return WarningsAsErrors; }

  /// \brief When set to true, any error reported is made a fatal error.
  void setErrorsAsFatal(bool Val) { ErrorsAsFatal = Val; }
  bool getErrorsAsFatal() const { return ErrorsAsFatal; }

  /// \brief When set to true mask warnings that come from system headers.
  void setSuppressSystemWarnings(bool Val) { SuppressSystemWarnings = Val; }
  bool getSuppressSystemWarnings() const { return SuppressSystemWarnings; }

  /// \brief Suppress all diagnostics, to silence the front end when we
  /// know that we don't want any more diagnostics to be passed along to the
  /// client
  void setSuppressAllDiagnostics(bool Val = true) {
    SuppressAllDiagnostics = Val;
  }
  bool getSuppressAllDiagnostics() const { return SuppressAllDiagnostics; }

  /// \brief Set type eliding, to skip outputting same types occurring in
  /// template types.
  void setElideType(bool Val = true) { ElideType = Val; }
  bool getElideType() { return ElideType; }

  /// \brief Set tree printing, to outputting the template difference in a
  /// tree format.
  void setPrintTemplateTree(bool Val = false) { PrintTemplateTree = Val; }
  bool getPrintTemplateTree() { return PrintTemplateTree; }

  /// \brief Set color printing, so the type diffing will inject color markers
  /// into the output.
  void setShowColors(bool Val = false) { ShowColors = Val; }
  bool getShowColors() { return ShowColors; }

  /// \brief Specify which overload candidates to show when overload resolution
  /// fails.
  ///
  /// By default, we show all candidates.
  void setShowOverloads(OverloadsShown Val) {
    ShowOverloads = Val;
  }
  OverloadsShown getShowOverloads() const { return ShowOverloads; }

  /// \brief Pretend that the last diagnostic issued was ignored, so any
  /// subsequent notes will be suppressed.
  ///
  /// This can be used by clients who suppress diagnostics themselves.
  void setLastDiagnosticIgnored() {
    if (LastDiagLevel == DiagnosticIDs::Fatal)
      FatalErrorOccurred = true;
    LastDiagLevel = DiagnosticIDs::Ignored;
  }

  /// \brief Determine whether the previous diagnostic was ignored. This can
  /// be used by clients that want to determine whether notes attached to a
  /// diagnostic will be suppressed.
  bool isLastDiagnosticIgnored() const {
    return LastDiagLevel == DiagnosticIDs::Ignored;
  }

  /// \brief Controls whether otherwise-unmapped extension diagnostics are
  /// mapped onto ignore/warning/error.
  ///
  /// This corresponds to the GCC -pedantic and -pedantic-errors option.
  void setExtensionHandlingBehavior(diag::Severity H) { ExtBehavior = H; }
  diag::Severity getExtensionHandlingBehavior() const { return ExtBehavior; }

  /// \brief Counter bumped when an __extension__  block is/ encountered.
  ///
  /// When non-zero, all extension diagnostics are entirely silenced, no
  /// matter how they are mapped.
  void IncrementAllExtensionsSilenced() { ++AllExtensionsSilenced; }
  void DecrementAllExtensionsSilenced() { --AllExtensionsSilenced; }
  bool hasAllExtensionsSilenced() { return AllExtensionsSilenced != 0; }

  /// \brief This allows the client to specify that certain warnings are
  /// ignored.
  ///
  /// Notes can never be mapped, errors can only be mapped to fatal, and
  /// WARNINGs and EXTENSIONs can be mapped arbitrarily.
  ///
  /// \param Loc The source location that this change of diagnostic state should
  /// take affect. It can be null if we are setting the latest state.
  void setSeverity(diag::kind Diag, diag::Severity Map, SourceLocation Loc);

  /// \brief Change an entire diagnostic group (e.g. "unknown-pragmas") to
  /// have the specified mapping.
  ///
  /// \returns true (and ignores the request) if "Group" was unknown, false
  /// otherwise.
  ///
  /// \param Loc The source location that this change of diagnostic state should
  /// take affect. It can be null if we are setting the state from command-line.
  bool setSeverityForGroup(StringRef Group, diag::Severity Map,
                           SourceLocation Loc = SourceLocation());

  /// \brief Set the warning-as-error flag for the given diagnostic group.
  ///
  /// This function always only operates on the current diagnostic state.
  ///
  /// \returns True if the given group is unknown, false otherwise.
  bool setDiagnosticGroupWarningAsError(StringRef Group, bool Enabled);

  /// \brief Set the error-as-fatal flag for the given diagnostic group.
  ///
  /// This function always only operates on the current diagnostic state.
  ///
  /// \returns True if the given group is unknown, false otherwise.
  bool setDiagnosticGroupErrorAsFatal(StringRef Group, bool Enabled);

  /// \brief Add the specified mapping to all diagnostics.
  ///
  /// Mainly to be used by -Wno-everything to disable all warnings but allow
  /// subsequent -W options to enable specific warnings.
  void setSeverityForAll(diag::Severity Map,
                         SourceLocation Loc = SourceLocation());

  bool hasErrorOccurred() const { return ErrorOccurred; }

  /// \brief Errors that actually prevent compilation, not those that are
  /// upgraded from a warning by -Werror.
  bool hasUncompilableErrorOccurred() const {
    return UncompilableErrorOccurred;
  }
  bool hasFatalErrorOccurred() const { return FatalErrorOccurred; }

  /// \brief Determine whether any kind of unrecoverable error has occurred.
  bool hasUnrecoverableErrorOccurred() const {
    return FatalErrorOccurred || UnrecoverableErrorOccurred;
  }

  unsigned getNumWarnings() const { return NumWarnings; }