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.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the Diagnostic-related interfaces.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_DIAGNOSTIC_H
#define LLVM_CLANG_DIAGNOSTIC_H

#include "clang/Basic/SourceLocation.h"
#include <string>
#include <cassert>

namespace llvm {
  template <typename T> class SmallVectorImpl;
}

namespace clang {
  class DiagnosticClient;
  class SourceRange;
  class SourceManager;
  class DiagnosticBuilder;
  class IdentifierInfo;

  // Import the diagnostic enums themselves.
  namespace diag {
    class CustomDiagInfo;

    /// diag::kind - All of the diagnostics that can be emitted by the frontend.
    enum kind {
#define DIAG(ENUM,FLAGS,DESC) ENUM,
#include "DiagnosticKinds.def"
      NUM_BUILTIN_DIAGNOSTICS
    };

    /// Enum values that allow the client to map NOTEs, WARNINGs, and EXTENSIONs
    /// to either MAP_IGNORE (nothing), MAP_WARNING (emit a warning), MAP_ERROR
    /// (emit as an error), or MAP_DEFAULT (handle the default way).
    enum Mapping {
      MAP_DEFAULT = 0,     //< Do not map this diagnostic.
      MAP_IGNORE  = 1,     //< Map this diagnostic to nothing, ignore it.
      MAP_WARNING = 2,     //< Map this diagnostic to a warning.
      MAP_ERROR   = 3      //< Map this diagnostic to an error.
    };
  }

/// Diagnostic - This concrete class is used by the front-end to report
/// problems and issues.  It massages the diagnostics (e.g. handling things like
/// "report warnings as errors" and passes them off to the DiagnosticClient for
/// reporting to the user.
class Diagnostic {
public:
  /// Level - The level of the diagnostic, after it has been through mapping.
  enum Level {
    Ignored, Note, Warning, Error
  };

  enum ArgumentKind {
    ak_std_string,     // std::string
    ak_c_string,       // const char *
    ak_sint,           // int
    ak_uint,           // unsigned
    ak_identifierinfo, // IdentifierInfo
    ak_qualtype        // QualType
  };

private:
  bool IgnoreAllWarnings;     // Ignore all warnings: -w
  bool WarningsAsErrors;      // Treat warnings like errors:
  bool WarnOnExtensions;      // Enables warnings for gcc extensions: -pedantic.
  bool ErrorOnExtensions;     // Error on extensions: -pedantic-errors.
  bool SuppressSystemWarnings;// Suppress warnings in system headers.
  DiagnosticClient *Client;

  /// DiagMappings - Mapping information for diagnostics.  Mapping info is
  /// packed into two bits per diagnostic.
  unsigned char DiagMappings[(diag::NUM_BUILTIN_DIAGNOSTICS+3)/4];

  /// ErrorOccurred - This is set to true when an error is emitted, and is
  /// sticky.
  bool ErrorOccurred;

  unsigned NumDiagnostics;    // Number of diagnostics reported
  unsigned NumErrors;         // Number of diagnostics that are errors

  /// CustomDiagInfo - Information for uniquing and looking up custom diags.
  diag::CustomDiagInfo *CustomDiagInfo;

  /// ArgToStringFn - A function pointer that converts an opaque diagnostic
  /// argument to a strings.  This takes the modifiers and argument that was
  /// present in the diagnostic.
  /// This is a hack to avoid a layering violation between libbasic and libsema.
  typedef void (*ArgToStringFnTy)(ArgumentKind Kind, intptr_t Val,
                                  const char *Modifier, unsigned ModifierLen,
                                  const char *Argument, unsigned ArgumentLen,
                                  llvm::SmallVectorImpl<char> &Output);
  ArgToStringFnTy ArgToStringFn;
public:
  explicit Diagnostic(DiagnosticClient *client = 0);
  ~Diagnostic();

  //===--------------------------------------------------------------------===//
  //  Diagnostic characterization methods, used by a client to customize how
  //

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

  void setClient(DiagnosticClient* client) { Client = client; }

  /// setIgnoreAllWarnings - 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; }

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

  /// setWarnOnExtensions - When set to true, issue warnings on GCC extensions,
  /// the equivalent of GCC's -pedantic.
  void setWarnOnExtensions(bool Val) { WarnOnExtensions = Val; }
  bool getWarnOnExtensions() const { return WarnOnExtensions; }

  /// setErrorOnExtensions - When set to true issue errors for GCC extensions
  /// instead of warnings.  This is the equivalent to GCC's -pedantic-errors.
  void setErrorOnExtensions(bool Val) { ErrorOnExtensions = Val; }
  bool getErrorOnExtensions() const { return ErrorOnExtensions; }

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

  /// setDiagnosticMapping - This allows the client to specify that certain
  /// warnings are ignored.  Only NOTEs, WARNINGs, and EXTENSIONs can be mapped.
  void setDiagnosticMapping(diag::kind Diag, diag::Mapping Map) {
    assert(Diag < diag::NUM_BUILTIN_DIAGNOSTICS &&
           "Can only map builtin diagnostics");
    assert(isBuiltinNoteWarningOrExtension(Diag) && "Cannot map errors!");
    unsigned char &Slot = DiagMappings[Diag/4];
    unsigned Bits = (Diag & 3)*2;
    Slot &= ~(3 << Bits);
    Slot |= Map << Bits;
  }

  /// getDiagnosticMapping - Return the mapping currently set for the specified
  /// diagnostic.
  diag::Mapping getDiagnosticMapping(diag::kind Diag) const {
    return (diag::Mapping)((DiagMappings[Diag/4] >> (Diag & 3)*2) & 3);
  }

  bool hasErrorOccurred() const { return ErrorOccurred; }

  unsigned getNumErrors() const { return NumErrors; }
  unsigned getNumDiagnostics() const { return NumDiagnostics; }

  /// getCustomDiagID - Return an ID for a diagnostic with the specified message
  /// and level.  If this is the first request for this diagnosic, it is
  /// registered and created, otherwise the existing ID is returned.
  unsigned getCustomDiagID(Level L, const char *Message);


  /// ConvertArgToString - This method converts a diagnostic argument (as an
  /// intptr_t) into the string that represents it.
  void ConvertArgToString(ArgumentKind Kind, intptr_t Val,
                          const char *Modifier, unsigned ModLen,
                          const char *Argument, unsigned ArgLen,
                          llvm::SmallVectorImpl<char> &Output) const {
    ArgToStringFn(Kind, Val, Modifier, ModLen, Argument, ArgLen, Output);
  }

  void SetArgToStringFn(ArgToStringFnTy Fn) {
    ArgToStringFn = Fn;
  }

  //===--------------------------------------------------------------------===//
  // Diagnostic classification and reporting interfaces.
  //

  /// getDescription - Given a diagnostic ID, return a description of the
  /// issue.
  const char *getDescription(unsigned DiagID) const;

  /// isBuiltinNoteWarningOrExtension - Return true if the unmapped diagnostic
  /// level of the specified diagnostic ID is a Note, Warning, or Extension.
  /// Note that this only works on builtin diagnostics, not custom ones.
  static bool isBuiltinNoteWarningOrExtension(unsigned DiagID);

  /// getDiagnosticLevel - Based on the way the client configured the Diagnostic
  /// object, classify the specified diagnostic ID into a Level, consumable by
  /// the DiagnosticClient.
  Level getDiagnosticLevel(unsigned DiagID) const;


  /// Report - Issue the message to the client.  DiagID is a member of the
  /// diag::kind enum.  This actually returns aninstance of DiagnosticBuilder
  /// which emits the diagnostics (through ProcessDiag) when it is destroyed.
  inline DiagnosticBuilder Report(FullSourceLoc Pos, unsigned DiagID);

private:
  // This is private state used by DiagnosticBuilder.  We put it here instead of
  // in DiagnosticBuilder in order to keep DiagnosticBuilder a small lightweight
  // object.  This implementation choice means that we can only have one
  // diagnostic "in flight" at a time, but this seems to be a reasonable
  // tradeoff to keep these objects small.  Assertions verify that only one
  // diagnostic is in flight at a time.
  friend class DiagnosticBuilder;
  friend class DiagnosticInfo;

  /// CurDiagLoc - This is the location of the current diagnostic that is in
  /// flight.
  FullSourceLoc CurDiagLoc;

  /// CurDiagID - This is the ID of the current diagnostic that is in flight.
  /// This is set to ~0U when there is no diagnostic in flight.
  unsigned CurDiagID;

  enum {
    /// MaxArguments - The maximum number of arguments we can hold. We currently
    /// only support up to 10 arguments (%0-%9).  A single diagnostic with more
    /// than that almost certainly has to be simplified anyway.
    MaxArguments = 10
  };

  /// NumDiagArgs - This contains the number of entries in Arguments.
  signed char NumDiagArgs;
  /// NumRanges - This is the number of ranges in the DiagRanges array.
  unsigned char NumDiagRanges;

  /// DiagArgumentsKind - This is an array of ArgumentKind::ArgumentKind enum
  /// values, with one for each argument.  This specifies whether the argument
  /// is in DiagArgumentsStr or in DiagArguments.
  unsigned char DiagArgumentsKind[MaxArguments];

  /// DiagArgumentsStr - This holds the values of each string argument for the
  /// current diagnostic.  This value is only used when the corresponding
  /// ArgumentKind is ak_std_string.
  std::string DiagArgumentsStr[MaxArguments];

  /// DiagArgumentsVal - The values for the various substitution positions. This
  /// is used when the argument is not an std::string.  The specific value is
  /// mangled into an intptr_t and the intepretation depends on exactly what
  /// sort of argument kind it is.
  intptr_t DiagArgumentsVal[MaxArguments];

  /// DiagRanges - The list of ranges added to this diagnostic.  It currently
  /// only support 10 ranges, could easily be extended if needed.
  const SourceRange *DiagRanges[10];

  /// ProcessDiag - This is the method used to report a diagnostic that is
  /// finally fully formed.
  void ProcessDiag();
};

//===----------------------------------------------------------------------===//
// DiagnosticBuilder
//===----------------------------------------------------------------------===//

/// DiagnosticBuilder - This is a little helper class used to produce
/// diagnostics.  This is constructed by the Diagnostic::Report method, and
/// allows insertion of extra information (arguments and source ranges) into the
/// currently "in flight" diagnostic.  When the temporary for the builder is
/// destroyed, the diagnostic is issued.
///
/// Note that many of these will be created as temporary objects (many call
/// sites), so we want them to be small and we never want their address taken.
/// This ensures that compilers with somewhat reasonable optimizers will promote
/// the common fields to registers, eliminating increments of the NumArgs field,
/// for example.
class DiagnosticBuilder {
  mutable Diagnostic *DiagObj;
  mutable unsigned NumArgs, NumRanges;

  void operator=(const DiagnosticBuilder&); // DO NOT IMPLEMENT
  friend class Diagnostic;
  explicit DiagnosticBuilder(Diagnostic *diagObj)
    : DiagObj(diagObj), NumArgs(0), NumRanges(0) {}
public:

  /// Copy constructor.  When copied, this "takes" the diagnostic info from the
  /// input and neuters it.
  DiagnosticBuilder(const DiagnosticBuilder &D) {
    DiagObj = D.DiagObj;
    D.DiagObj = 0;
  }

  /// Destructor - The dtor emits the diagnostic.
  ~DiagnosticBuilder() {
    // If DiagObj is null, then its soul was stolen by the copy ctor.
    if (DiagObj == 0) return;

    // When destroyed, the ~DiagnosticBuilder sets the final argument count into
    // the Diagnostic object.
    DiagObj->NumDiagArgs = NumArgs;
    DiagObj->NumDiagRanges = NumRanges;

    // Process the diagnostic, sending the accumulated information to the
    // DiagnosticClient.
    DiagObj->ProcessDiag();

    // This diagnostic is no longer in flight.
    DiagObj->CurDiagID = ~0U;
  }

  /// Operator bool: conversion of DiagnosticBuilder to bool always returns
  /// true.  This allows is to be used in boolean error contexts like:
  /// return Diag(...);
  operator bool() const { return true; }

  void AddString(const std::string &S) const {
    assert(NumArgs < Diagnostic::MaxArguments &&
           "Too many arguments to diagnostic!");
    DiagObj->DiagArgumentsKind[NumArgs] = Diagnostic::ak_std_string;
    DiagObj->DiagArgumentsStr[NumArgs++] = S;
  }

  void AddTaggedVal(intptr_t V, Diagnostic::ArgumentKind Kind) const {
    assert(NumArgs < Diagnostic::MaxArguments &&
           "Too many arguments to diagnostic!");
    DiagObj->DiagArgumentsKind[NumArgs] = Kind;
    DiagObj->DiagArgumentsVal[NumArgs++] = V;
  }

  void AddSourceRange(const SourceRange &R) const {
    assert(NumRanges <
           sizeof(DiagObj->DiagRanges)/sizeof(DiagObj->DiagRanges[0]) &&
           "Too many arguments to diagnostic!");
    DiagObj->DiagRanges[NumRanges++] = &R;
  }
};

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
                                           const std::string &S) {
  DB.AddString(S);
  return DB;
}

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
                                           const char *Str) {
  DB.AddTaggedVal(reinterpret_cast<intptr_t>(Str),
                  Diagnostic::ak_c_string);
  return DB;
}

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB, int I) {
  DB.AddTaggedVal(I, Diagnostic::ak_sint);
  return DB;
}

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
                                           unsigned I) {
  DB.AddTaggedVal(I, Diagnostic::ak_uint);
  return DB;
}

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
                                           const IdentifierInfo *II) {
  DB.AddTaggedVal(reinterpret_cast<intptr_t>(II),
                  Diagnostic::ak_identifierinfo);
  return DB;
}

inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
                                           const SourceRange &R) {
  DB.AddSourceRange(R);
  return DB;
}


/// Report - Issue the message to the client.  DiagID is a member of the
/// diag::kind enum.  This actually returns a new instance of DiagnosticBuilder
/// which emits the diagnostics (through ProcessDiag) when it is destroyed.
inline DiagnosticBuilder Diagnostic::Report(FullSourceLoc Loc, unsigned DiagID){
  assert(CurDiagID == ~0U && "Multiple diagnostics in flight at once!");
  CurDiagLoc = Loc;
  CurDiagID = DiagID;
  return DiagnosticBuilder(this);
}

//===----------------------------------------------------------------------===//
// DiagnosticInfo
//===----------------------------------------------------------------------===//

/// DiagnosticInfo - This is a little helper class (which is basically a smart
/// pointer that forward info from Diagnostic) that allows clients ot enquire
/// about the currently in-flight diagnostic.
class DiagnosticInfo {
  const Diagnostic *DiagObj;
public:
  explicit DiagnosticInfo(const Diagnostic *DO) : DiagObj(DO) {}

  const Diagnostic *getDiags() const { return DiagObj; }
  unsigned getID() const { return DiagObj->CurDiagID; }
  const FullSourceLoc &getLocation() const { return DiagObj->CurDiagLoc; }

  unsigned getNumArgs() const { return DiagObj->NumDiagArgs; }

  /// getArgKind - Return the kind of the specified index.  Based on the kind
  /// of argument, the accessors below can be used to get the value.
  Diagnostic::ArgumentKind getArgKind(unsigned Idx) const {
    assert(Idx < getNumArgs() && "Argument index out of range!");
    return (Diagnostic::ArgumentKind)DiagObj->DiagArgumentsKind[Idx];
  }

  /// getArgStdStr - Return the provided argument string specified by Idx.
  const std::string &getArgStdStr(unsigned Idx) const {
    assert(getArgKind(Idx) == Diagnostic::ak_std_string &&
           "invalid argument accessor!");
    return DiagObj->DiagArgumentsStr[Idx];
  }

  /// getArgCStr - Return the specified C string argument.
  const char *getArgCStr(unsigned Idx) const {
    assert(getArgKind(Idx) == Diagnostic::ak_c_string &&
           "invalid argument accessor!");
    return reinterpret_cast<const char*>(DiagObj->DiagArgumentsVal[Idx]);
  }

  /// getArgSInt - Return the specified signed integer argument.
  int getArgSInt(unsigned Idx) const {
    assert(getArgKind(Idx) == Diagnostic::ak_sint &&
           "invalid argument accessor!");
    return (int)DiagObj->DiagArgumentsVal[Idx];
  }

  /// getArgUInt - Return the specified unsigned integer argument.
  unsigned getArgUInt(unsigned Idx) const {
    assert(getArgKind(Idx) == Diagnostic::ak_uint &&
           "invalid argument accessor!");
    return (unsigned)DiagObj->DiagArgumentsVal[Idx];
  }

  /// getArgIdentifier - Return the specified IdentifierInfo argument.
  const IdentifierInfo *getArgIdentifier(unsigned Idx) const {
    assert(getArgKind(Idx) == Diagnostic::ak_identifierinfo &&
           "invalid argument accessor!");
    return reinterpret_cast<IdentifierInfo*>(DiagObj->DiagArgumentsVal[Idx]);
  }

  /// getRawArg - Return the specified non-string argument in an opaque form.
  intptr_t getRawArg(unsigned Idx) const {
    assert(getArgKind(Idx) != Diagnostic::ak_std_string &&
           "invalid argument accessor!");
    return DiagObj->DiagArgumentsVal[Idx];
  }


  /// getNumRanges - Return the number of source ranges associated with this
  /// diagnostic.
  unsigned getNumRanges() const {
    return DiagObj->NumDiagRanges;
  }

  const SourceRange &getRange(unsigned Idx) const {
    assert(Idx < DiagObj->NumDiagRanges && "Invalid diagnostic range index!");
    return *DiagObj->DiagRanges[Idx];
  }


  /// FormatDiagnostic - Format this diagnostic into a string, substituting the
  /// formal arguments into the %0 slots.  The result is appended onto the Str
  /// array.
  void FormatDiagnostic(llvm::SmallVectorImpl<char> &OutStr) const;
};


/// DiagnosticClient - This is an abstract interface implemented by clients of
/// the front-end, which formats and prints fully processed diagnostics.
class DiagnosticClient {
public:
  virtual ~DiagnosticClient();

  /// HandleDiagnostic - Handle this diagnostic, reporting it to the user or
  /// capturing it to a log as needed.
  virtual void HandleDiagnostic(Diagnostic::Level DiagLevel,
                                const DiagnosticInfo &Info) = 0;
};

}  // end namespace clang

#endif