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  1. //===- Diagnostic.h - C Language Family Diagnostic Handling -----*- C++ -*-===//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. //
  9. /// \file
  10. /// Defines the Diagnostic-related interfaces.
  11. //
  12. //===----------------------------------------------------------------------===//
  13.  
  14. #ifndef LLVM_CLANG_BASIC_DIAGNOSTIC_H
  15. #define LLVM_CLANG_BASIC_DIAGNOSTIC_H
  16.  
  17. #include "clang/Basic/DiagnosticIDs.h"
  18. #include "clang/Basic/DiagnosticOptions.h"
  19. #include "clang/Basic/SourceLocation.h"
  20. #include "clang/Basic/Specifiers.h"
  21. #include "llvm/ADT/ArrayRef.h"
  22. #include "llvm/ADT/DenseMap.h"
  23. #include "llvm/ADT/IntrusiveRefCntPtr.h"
  24. #include "llvm/ADT/SmallVector.h"
  25. #include "llvm/ADT/StringRef.h"
  26. #include "llvm/ADT/iterator_range.h"
  27. #include "llvm/Support/Compiler.h"
  28. #include <cassert>
  29. #include <cstdint>
  30. #include <limits>
  31. #include <list>
  32. #include <map>
  33. #include <memory>
  34. #include <optional>
  35. #include <string>
  36. #include <type_traits>
  37. #include <utility>
  38. #include <vector>
  39.  
  40. namespace llvm {
  41. class Error;
  42. class raw_ostream;
  43. } // namespace llvm
  44.  
  45. namespace clang {
  46.  
  47. class DeclContext;
  48. class DiagnosticBuilder;
  49. class DiagnosticConsumer;
  50. class IdentifierInfo;
  51. class LangOptions;
  52. class Preprocessor;
  53. class SourceManager;
  54. class StoredDiagnostic;
  55.  
  56. namespace tok {
  57.  
  58. enum TokenKind : unsigned short;
  59.  
  60. } // namespace tok
  61.  
  62. /// Annotates a diagnostic with some code that should be
  63. /// inserted, removed, or replaced to fix the problem.
  64. ///
  65. /// This kind of hint should be used when we are certain that the
  66. /// introduction, removal, or modification of a particular (small!)
  67. /// amount of code will correct a compilation error. The compiler
  68. /// should also provide full recovery from such errors, such that
  69. /// suppressing the diagnostic output can still result in successful
  70. /// compilation.
  71. class FixItHint {
  72. public:
  73.   /// Code that should be replaced to correct the error. Empty for an
  74.   /// insertion hint.
  75.   CharSourceRange RemoveRange;
  76.  
  77.   /// Code in the specific range that should be inserted in the insertion
  78.   /// location.
  79.   CharSourceRange InsertFromRange;
  80.  
  81.   /// The actual code to insert at the insertion location, as a
  82.   /// string.
  83.   std::string CodeToInsert;
  84.  
  85.   bool BeforePreviousInsertions = false;
  86.  
  87.   /// Empty code modification hint, indicating that no code
  88.   /// modification is known.
  89.   FixItHint() = default;
  90.  
  91.   bool isNull() const {
  92.     return !RemoveRange.isValid();
  93.   }
  94.  
  95.   /// Create a code modification hint that inserts the given
  96.   /// code string at a specific location.
  97.   static FixItHint CreateInsertion(SourceLocation InsertionLoc,
  98.                                    StringRef Code,
  99.                                    bool BeforePreviousInsertions = false) {
  100.     FixItHint Hint;
  101.     Hint.RemoveRange =
  102.       CharSourceRange::getCharRange(InsertionLoc, InsertionLoc);
  103.     Hint.CodeToInsert = std::string(Code);
  104.     Hint.BeforePreviousInsertions = BeforePreviousInsertions;
  105.     return Hint;
  106.   }
  107.  
  108.   /// Create a code modification hint that inserts the given
  109.   /// code from \p FromRange at a specific location.
  110.   static FixItHint CreateInsertionFromRange(SourceLocation InsertionLoc,
  111.                                             CharSourceRange FromRange,
  112.                                         bool BeforePreviousInsertions = false) {
  113.     FixItHint Hint;
  114.     Hint.RemoveRange =
  115.       CharSourceRange::getCharRange(InsertionLoc, InsertionLoc);
  116.     Hint.InsertFromRange = FromRange;
  117.     Hint.BeforePreviousInsertions = BeforePreviousInsertions;
  118.     return Hint;
  119.   }
  120.  
  121.   /// Create a code modification hint that removes the given
  122.   /// source range.
  123.   static FixItHint CreateRemoval(CharSourceRange RemoveRange) {
  124.     FixItHint Hint;
  125.     Hint.RemoveRange = RemoveRange;
  126.     return Hint;
  127.   }
  128.   static FixItHint CreateRemoval(SourceRange RemoveRange) {
  129.     return CreateRemoval(CharSourceRange::getTokenRange(RemoveRange));
  130.   }
  131.  
  132.   /// Create a code modification hint that replaces the given
  133.   /// source range with the given code string.
  134.   static FixItHint CreateReplacement(CharSourceRange RemoveRange,
  135.                                      StringRef Code) {
  136.     FixItHint Hint;
  137.     Hint.RemoveRange = RemoveRange;
  138.     Hint.CodeToInsert = std::string(Code);
  139.     return Hint;
  140.   }
  141.  
  142.   static FixItHint CreateReplacement(SourceRange RemoveRange,
  143.                                      StringRef Code) {
  144.     return CreateReplacement(CharSourceRange::getTokenRange(RemoveRange), Code);
  145.   }
  146. };
  147.  
  148. struct DiagnosticStorage {
  149.   enum {
  150.     /// The maximum number of arguments we can hold. We
  151.     /// currently only support up to 10 arguments (%0-%9).
  152.     ///
  153.     /// A single diagnostic with more than that almost certainly has to
  154.     /// be simplified anyway.
  155.     MaxArguments = 10
  156.   };
  157.  
  158.   /// The number of entries in Arguments.
  159.   unsigned char NumDiagArgs = 0;
  160.  
  161.   /// Specifies for each argument whether it is in DiagArgumentsStr
  162.   /// or in DiagArguments.
  163.   unsigned char DiagArgumentsKind[MaxArguments];
  164.  
  165.   /// The values for the various substitution positions.
  166.   ///
  167.   /// This is used when the argument is not an std::string. The specific value
  168.   /// is mangled into an uint64_t and the interpretation depends on exactly
  169.   /// what sort of argument kind it is.
  170.   uint64_t DiagArgumentsVal[MaxArguments];
  171.  
  172.   /// The values for the various substitution positions that have
  173.   /// string arguments.
  174.   std::string DiagArgumentsStr[MaxArguments];
  175.  
  176.   /// The list of ranges added to this diagnostic.
  177.   SmallVector<CharSourceRange, 8> DiagRanges;
  178.  
  179.   /// If valid, provides a hint with some code to insert, remove, or
  180.   /// modify at a particular position.
  181.   SmallVector<FixItHint, 6> FixItHints;
  182.  
  183.   DiagnosticStorage() = default;
  184. };
  185.  
  186. /// Concrete class used by the front-end to report problems and issues.
  187. ///
  188. /// This massages the diagnostics (e.g. handling things like "report warnings
  189. /// as errors" and passes them off to the DiagnosticConsumer for reporting to
  190. /// the user. DiagnosticsEngine is tied to one translation unit and one
  191. /// SourceManager.
  192. class DiagnosticsEngine : public RefCountedBase<DiagnosticsEngine> {
  193. public:
  194.   /// The level of the diagnostic, after it has been through mapping.
  195.   enum Level {
  196.     Ignored = DiagnosticIDs::Ignored,
  197.     Note = DiagnosticIDs::Note,
  198.     Remark = DiagnosticIDs::Remark,
  199.     Warning = DiagnosticIDs::Warning,
  200.     Error = DiagnosticIDs::Error,
  201.     Fatal = DiagnosticIDs::Fatal
  202.   };
  203.  
  204.   enum ArgumentKind {
  205.     /// std::string
  206.     ak_std_string,
  207.  
  208.     /// const char *
  209.     ak_c_string,
  210.  
  211.     /// int
  212.     ak_sint,
  213.  
  214.     /// unsigned
  215.     ak_uint,
  216.  
  217.     /// enum TokenKind : unsigned
  218.     ak_tokenkind,
  219.  
  220.     /// IdentifierInfo
  221.     ak_identifierinfo,
  222.  
  223.     /// address space
  224.     ak_addrspace,
  225.  
  226.     /// Qualifiers
  227.     ak_qual,
  228.  
  229.     /// QualType
  230.     ak_qualtype,
  231.  
  232.     /// DeclarationName
  233.     ak_declarationname,
  234.  
  235.     /// NamedDecl *
  236.     ak_nameddecl,
  237.  
  238.     /// NestedNameSpecifier *
  239.     ak_nestednamespec,
  240.  
  241.     /// DeclContext *
  242.     ak_declcontext,
  243.  
  244.     /// pair<QualType, QualType>
  245.     ak_qualtype_pair,
  246.  
  247.     /// Attr *
  248.     ak_attr
  249.   };
  250.  
  251.   /// Represents on argument value, which is a union discriminated
  252.   /// by ArgumentKind, with a value.
  253.   using ArgumentValue = std::pair<ArgumentKind, intptr_t>;
  254.  
  255. private:
  256.   // Used by __extension__
  257.   unsigned char AllExtensionsSilenced = 0;
  258.  
  259.   // Treat fatal errors like errors.
  260.   bool FatalsAsError = false;
  261.  
  262.   // Suppress all diagnostics.
  263.   bool SuppressAllDiagnostics = false;
  264.  
  265.   // Elide common types of templates.
  266.   bool ElideType = true;
  267.  
  268.   // Print a tree when comparing templates.
  269.   bool PrintTemplateTree = false;
  270.  
  271.   // Color printing is enabled.
  272.   bool ShowColors = false;
  273.  
  274.   // Which overload candidates to show.
  275.   OverloadsShown ShowOverloads = Ovl_All;
  276.  
  277.   // With Ovl_Best, the number of overload candidates to show when we encounter
  278.   // an error.
  279.   //
  280.   // The value here is the number of candidates to show in the first nontrivial
  281.   // error.  Future errors may show a different number of candidates.
  282.   unsigned NumOverloadsToShow = 32;
  283.  
  284.   // Cap of # errors emitted, 0 -> no limit.
  285.   unsigned ErrorLimit = 0;
  286.  
  287.   // Cap on depth of template backtrace stack, 0 -> no limit.
  288.   unsigned TemplateBacktraceLimit = 0;
  289.  
  290.   // Cap on depth of constexpr evaluation backtrace stack, 0 -> no limit.
  291.   unsigned ConstexprBacktraceLimit = 0;
  292.  
  293.   IntrusiveRefCntPtr<DiagnosticIDs> Diags;
  294.   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts;
  295.   DiagnosticConsumer *Client = nullptr;
  296.   std::unique_ptr<DiagnosticConsumer> Owner;
  297.   SourceManager *SourceMgr = nullptr;
  298.  
  299.   /// Mapping information for diagnostics.
  300.   ///
  301.   /// Mapping info is packed into four bits per diagnostic.  The low three
  302.   /// bits are the mapping (an instance of diag::Severity), or zero if unset.
  303.   /// The high bit is set when the mapping was established as a user mapping.
  304.   /// If the high bit is clear, then the low bits are set to the default
  305.   /// value, and should be mapped with -pedantic, -Werror, etc.
  306.   ///
  307.   /// A new DiagState is created and kept around when diagnostic pragmas modify
  308.   /// the state so that we know what is the diagnostic state at any given
  309.   /// source location.
  310.   class DiagState {
  311.     llvm::DenseMap<unsigned, DiagnosticMapping> DiagMap;
  312.  
  313.   public:
  314.     // "Global" configuration state that can actually vary between modules.
  315.  
  316.     // Ignore all warnings: -w
  317.     unsigned IgnoreAllWarnings : 1;
  318.  
  319.     // Enable all warnings.
  320.     unsigned EnableAllWarnings : 1;
  321.  
  322.     // Treat warnings like errors.
  323.     unsigned WarningsAsErrors : 1;
  324.  
  325.     // Treat errors like fatal errors.
  326.     unsigned ErrorsAsFatal : 1;
  327.  
  328.     // Suppress warnings in system headers.
  329.     unsigned SuppressSystemWarnings : 1;
  330.  
  331.     // Map extensions to warnings or errors?
  332.     diag::Severity ExtBehavior = diag::Severity::Ignored;
  333.  
  334.     DiagState()
  335.         : IgnoreAllWarnings(false), EnableAllWarnings(false),
  336.           WarningsAsErrors(false), ErrorsAsFatal(false),
  337.           SuppressSystemWarnings(false) {}
  338.  
  339.     using iterator = llvm::DenseMap<unsigned, DiagnosticMapping>::iterator;
  340.     using const_iterator =
  341.         llvm::DenseMap<unsigned, DiagnosticMapping>::const_iterator;
  342.  
  343.     void setMapping(diag::kind Diag, DiagnosticMapping Info) {
  344.       DiagMap[Diag] = Info;
  345.     }
  346.  
  347.     DiagnosticMapping lookupMapping(diag::kind Diag) const {
  348.       return DiagMap.lookup(Diag);
  349.     }
  350.  
  351.     DiagnosticMapping &getOrAddMapping(diag::kind Diag);
  352.  
  353.     const_iterator begin() const { return DiagMap.begin(); }
  354.     const_iterator end() const { return DiagMap.end(); }
  355.   };
  356.  
  357.   /// Keeps and automatically disposes all DiagStates that we create.
  358.   std::list<DiagState> DiagStates;
  359.  
  360.   /// A mapping from files to the diagnostic states for those files. Lazily
  361.   /// built on demand for files in which the diagnostic state has not changed.
  362.   class DiagStateMap {
  363.   public:
  364.     /// Add an initial diagnostic state.
  365.     void appendFirst(DiagState *State);
  366.  
  367.     /// Add a new latest state point.
  368.     void append(SourceManager &SrcMgr, SourceLocation Loc, DiagState *State);
  369.  
  370.     /// Look up the diagnostic state at a given source location.
  371.     DiagState *lookup(SourceManager &SrcMgr, SourceLocation Loc) const;
  372.  
  373.     /// Determine whether this map is empty.
  374.     bool empty() const { return Files.empty(); }
  375.  
  376.     /// Clear out this map.
  377.     void clear() {
  378.       Files.clear();
  379.       FirstDiagState = CurDiagState = nullptr;
  380.       CurDiagStateLoc = SourceLocation();
  381.     }
  382.  
  383.     /// Produce a debugging dump of the diagnostic state.
  384.     LLVM_DUMP_METHOD void dump(SourceManager &SrcMgr,
  385.                                StringRef DiagName = StringRef()) const;
  386.  
  387.     /// Grab the most-recently-added state point.
  388.     DiagState *getCurDiagState() const { return CurDiagState; }
  389.  
  390.     /// Get the location at which a diagnostic state was last added.
  391.     SourceLocation getCurDiagStateLoc() const { return CurDiagStateLoc; }
  392.  
  393.   private:
  394.     friend class ASTReader;
  395.     friend class ASTWriter;
  396.  
  397.     /// Represents a point in source where the diagnostic state was
  398.     /// modified because of a pragma.
  399.     ///
  400.     /// 'Loc' can be null if the point represents the diagnostic state
  401.     /// modifications done through the command-line.
  402.     struct DiagStatePoint {
  403.       DiagState *State;
  404.       unsigned Offset;
  405.  
  406.       DiagStatePoint(DiagState *State, unsigned Offset)
  407.           : State(State), Offset(Offset) {}
  408.     };
  409.  
  410.     /// Description of the diagnostic states and state transitions for a
  411.     /// particular FileID.
  412.     struct File {
  413.       /// The diagnostic state for the parent file. This is strictly redundant,
  414.       /// as looking up the DecomposedIncludedLoc for the FileID in the Files
  415.       /// map would give us this, but we cache it here for performance.
  416.       File *Parent = nullptr;
  417.  
  418.       /// The offset of this file within its parent.
  419.       unsigned ParentOffset = 0;
  420.  
  421.       /// Whether this file has any local (not imported from an AST file)
  422.       /// diagnostic state transitions.
  423.       bool HasLocalTransitions = false;
  424.  
  425.       /// The points within the file where the state changes. There will always
  426.       /// be at least one of these (the state on entry to the file).
  427.       llvm::SmallVector<DiagStatePoint, 4> StateTransitions;
  428.  
  429.       DiagState *lookup(unsigned Offset) const;
  430.     };
  431.  
  432.     /// The diagnostic states for each file.
  433.     mutable std::map<FileID, File> Files;
  434.  
  435.     /// The initial diagnostic state.
  436.     DiagState *FirstDiagState;
  437.  
  438.     /// The current diagnostic state.
  439.     DiagState *CurDiagState;
  440.  
  441.     /// The location at which the current diagnostic state was established.
  442.     SourceLocation CurDiagStateLoc;
  443.  
  444.     /// Get the diagnostic state information for a file.
  445.     File *getFile(SourceManager &SrcMgr, FileID ID) const;
  446.   };
  447.  
  448.   DiagStateMap DiagStatesByLoc;
  449.  
  450.   /// Keeps the DiagState that was active during each diagnostic 'push'
  451.   /// so we can get back at it when we 'pop'.
  452.   std::vector<DiagState *> DiagStateOnPushStack;
  453.  
  454.   DiagState *GetCurDiagState() const {
  455.     return DiagStatesByLoc.getCurDiagState();
  456.   }
  457.  
  458.   void PushDiagStatePoint(DiagState *State, SourceLocation L);
  459.  
  460.   /// Finds the DiagStatePoint that contains the diagnostic state of
  461.   /// the given source location.
  462.   DiagState *GetDiagStateForLoc(SourceLocation Loc) const {
  463.     return SourceMgr ? DiagStatesByLoc.lookup(*SourceMgr, Loc)
  464.                      : DiagStatesByLoc.getCurDiagState();
  465.   }
  466.  
  467.   /// Sticky flag set to \c true when an error is emitted.
  468.   bool ErrorOccurred;
  469.  
  470.   /// Sticky flag set to \c true when an "uncompilable error" occurs.
  471.   /// I.e. an error that was not upgraded from a warning by -Werror.
  472.   bool UncompilableErrorOccurred;
  473.  
  474.   /// Sticky flag set to \c true when a fatal error is emitted.
  475.   bool FatalErrorOccurred;
  476.  
  477.   /// Indicates that an unrecoverable error has occurred.
  478.   bool UnrecoverableErrorOccurred;
  479.  
  480.   /// Counts for DiagnosticErrorTrap to check whether an error occurred
  481.   /// during a parsing section, e.g. during parsing a function.
  482.   unsigned TrapNumErrorsOccurred;
  483.   unsigned TrapNumUnrecoverableErrorsOccurred;
  484.  
  485.   /// The level of the last diagnostic emitted.
  486.   ///
  487.   /// This is used to emit continuation diagnostics with the same level as the
  488.   /// diagnostic that they follow.
  489.   DiagnosticIDs::Level LastDiagLevel;
  490.  
  491.   /// Number of warnings reported
  492.   unsigned NumWarnings;
  493.  
  494.   /// Number of errors reported
  495.   unsigned NumErrors;
  496.  
  497.   /// A function pointer that converts an opaque diagnostic
  498.   /// argument to a strings.
  499.   ///
  500.   /// This takes the modifiers and argument that was present in the diagnostic.
  501.   ///
  502.   /// The PrevArgs array indicates the previous arguments formatted for this
  503.   /// diagnostic.  Implementations of this function can use this information to
  504.   /// avoid redundancy across arguments.
  505.   ///
  506.   /// This is a hack to avoid a layering violation between libbasic and libsema.
  507.   using ArgToStringFnTy = void (*)(
  508.       ArgumentKind Kind, intptr_t Val,
  509.       StringRef Modifier, StringRef Argument,
  510.       ArrayRef<ArgumentValue> PrevArgs,
  511.       SmallVectorImpl<char> &Output,
  512.       void *Cookie,
  513.       ArrayRef<intptr_t> QualTypeVals);
  514.  
  515.   void *ArgToStringCookie = nullptr;
  516.   ArgToStringFnTy ArgToStringFn;
  517.  
  518.   /// ID of the "delayed" diagnostic, which is a (typically
  519.   /// fatal) diagnostic that had to be delayed because it was found
  520.   /// while emitting another diagnostic.
  521.   unsigned DelayedDiagID;
  522.  
  523.   /// First string argument for the delayed diagnostic.
  524.   std::string DelayedDiagArg1;
  525.  
  526.   /// Second string argument for the delayed diagnostic.
  527.   std::string DelayedDiagArg2;
  528.  
  529.   /// Third string argument for the delayed diagnostic.
  530.   std::string DelayedDiagArg3;
  531.  
  532.   /// Optional flag value.
  533.   ///
  534.   /// Some flags accept values, for instance: -Wframe-larger-than=<value> and
  535.   /// -Rpass=<value>. The content of this string is emitted after the flag name
  536.   /// and '='.
  537.   std::string FlagValue;
  538.  
  539. public:
  540.   explicit DiagnosticsEngine(IntrusiveRefCntPtr<DiagnosticIDs> Diags,
  541.                              IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts,
  542.                              DiagnosticConsumer *client = nullptr,
  543.                              bool ShouldOwnClient = true);
  544.   DiagnosticsEngine(const DiagnosticsEngine &) = delete;
  545.   DiagnosticsEngine &operator=(const DiagnosticsEngine &) = delete;
  546.   ~DiagnosticsEngine();
  547.  
  548.   friend void DiagnosticsTestHelper(DiagnosticsEngine &);
  549.   LLVM_DUMP_METHOD void dump() const;
  550.   LLVM_DUMP_METHOD void dump(StringRef DiagName) const;
  551.  
  552.   const IntrusiveRefCntPtr<DiagnosticIDs> &getDiagnosticIDs() const {
  553.     return Diags;
  554.   }
  555.  
  556.   /// Retrieve the diagnostic options.
  557.   DiagnosticOptions &getDiagnosticOptions() const { return *DiagOpts; }
  558.  
  559.   using diag_mapping_range = llvm::iterator_range<DiagState::const_iterator>;
  560.  
  561.   /// Get the current set of diagnostic mappings.
  562.   diag_mapping_range getDiagnosticMappings() const {
  563.     const DiagState &DS = *GetCurDiagState();
  564.     return diag_mapping_range(DS.begin(), DS.end());
  565.   }
  566.  
  567.   DiagnosticConsumer *getClient() { return Client; }
  568.   const DiagnosticConsumer *getClient() const { return Client; }
  569.  
  570.   /// Determine whether this \c DiagnosticsEngine object own its client.
  571.   bool ownsClient() const { return Owner != nullptr; }
  572.  
  573.   /// Return the current diagnostic client along with ownership of that
  574.   /// client.
  575.   std::unique_ptr<DiagnosticConsumer> takeClient() { return std::move(Owner); }
  576.  
  577.   bool hasSourceManager() const { return SourceMgr != nullptr; }
  578.  
  579.   SourceManager &getSourceManager() const {
  580.     assert(SourceMgr && "SourceManager not set!");
  581.     return *SourceMgr;
  582.   }
  583.  
  584.   void setSourceManager(SourceManager *SrcMgr) {
  585.     assert(DiagStatesByLoc.empty() &&
  586.            "Leftover diag state from a different SourceManager.");
  587.     SourceMgr = SrcMgr;
  588.   }
  589.  
  590.   //===--------------------------------------------------------------------===//
  591.   //  DiagnosticsEngine characterization methods, used by a client to customize
  592.   //  how diagnostics are emitted.
  593.   //
  594.  
  595.   /// Copies the current DiagMappings and pushes the new copy
  596.   /// onto the top of the stack.
  597.   void pushMappings(SourceLocation Loc);
  598.  
  599.   /// Pops the current DiagMappings off the top of the stack,
  600.   /// causing the new top of the stack to be the active mappings.
  601.   ///
  602.   /// \returns \c true if the pop happens, \c false if there is only one
  603.   /// DiagMapping on the stack.
  604.   bool popMappings(SourceLocation Loc);
  605.  
  606.   /// Set the diagnostic client associated with this diagnostic object.
  607.   ///
  608.   /// \param ShouldOwnClient true if the diagnostic object should take
  609.   /// ownership of \c client.
  610.   void setClient(DiagnosticConsumer *client, bool ShouldOwnClient = true);
  611.  
  612.   /// Specify a limit for the number of errors we should
  613.   /// emit before giving up.
  614.   ///
  615.   /// Zero disables the limit.
  616.   void setErrorLimit(unsigned Limit) { ErrorLimit = Limit; }
  617.  
  618.   /// Specify the maximum number of template instantiation
  619.   /// notes to emit along with a given diagnostic.
  620.   void setTemplateBacktraceLimit(unsigned Limit) {
  621.     TemplateBacktraceLimit = Limit;
  622.   }
  623.  
  624.   /// Retrieve the maximum number of template instantiation
  625.   /// notes to emit along with a given diagnostic.
  626.   unsigned getTemplateBacktraceLimit() const {
  627.     return TemplateBacktraceLimit;
  628.   }
  629.  
  630.   /// Specify the maximum number of constexpr evaluation
  631.   /// notes to emit along with a given diagnostic.
  632.   void setConstexprBacktraceLimit(unsigned Limit) {
  633.     ConstexprBacktraceLimit = Limit;
  634.   }
  635.  
  636.   /// Retrieve the maximum number of constexpr evaluation
  637.   /// notes to emit along with a given diagnostic.
  638.   unsigned getConstexprBacktraceLimit() const {
  639.     return ConstexprBacktraceLimit;
  640.   }
  641.  
  642.   /// When set to true, any unmapped warnings are ignored.
  643.   ///
  644.   /// If this and WarningsAsErrors are both set, then this one wins.
  645.   void setIgnoreAllWarnings(bool Val) {
  646.     GetCurDiagState()->IgnoreAllWarnings = Val;
  647.   }
  648.   bool getIgnoreAllWarnings() const {
  649.     return GetCurDiagState()->IgnoreAllWarnings;
  650.   }
  651.  
  652.   /// When set to true, any unmapped ignored warnings are no longer
  653.   /// ignored.
  654.   ///
  655.   /// If this and IgnoreAllWarnings are both set, then that one wins.
  656.   void setEnableAllWarnings(bool Val) {
  657.     GetCurDiagState()->EnableAllWarnings = Val;
  658.   }
  659.   bool getEnableAllWarnings() const {
  660.     return GetCurDiagState()->EnableAllWarnings;
  661.   }
  662.  
  663.   /// When set to true, any warnings reported are issued as errors.
  664.   void setWarningsAsErrors(bool Val) {
  665.     GetCurDiagState()->WarningsAsErrors = Val;
  666.   }
  667.   bool getWarningsAsErrors() const {
  668.     return GetCurDiagState()->WarningsAsErrors;
  669.   }
  670.  
  671.   /// When set to true, any error reported is made a fatal error.
  672.   void setErrorsAsFatal(bool Val) { GetCurDiagState()->ErrorsAsFatal = Val; }
  673.   bool getErrorsAsFatal() const { return GetCurDiagState()->ErrorsAsFatal; }
  674.  
  675.   /// \brief When set to true, any fatal error reported is made an error.
  676.   ///
  677.   /// This setting takes precedence over the setErrorsAsFatal setting above.
  678.   void setFatalsAsError(bool Val) { FatalsAsError = Val; }
  679.   bool getFatalsAsError() const { return FatalsAsError; }
  680.  
  681.   /// When set to true mask warnings that come from system headers.
  682.   void setSuppressSystemWarnings(bool Val) {
  683.     GetCurDiagState()->SuppressSystemWarnings = Val;
  684.   }
  685.   bool getSuppressSystemWarnings() const {
  686.     return GetCurDiagState()->SuppressSystemWarnings;
  687.   }
  688.  
  689.   /// Suppress all diagnostics, to silence the front end when we
  690.   /// know that we don't want any more diagnostics to be passed along to the
  691.   /// client
  692.   void setSuppressAllDiagnostics(bool Val) { SuppressAllDiagnostics = Val; }
  693.   bool getSuppressAllDiagnostics() const { return SuppressAllDiagnostics; }
  694.  
  695.   /// Set type eliding, to skip outputting same types occurring in
  696.   /// template types.
  697.   void setElideType(bool Val) { ElideType = Val; }
  698.   bool getElideType() { return ElideType; }
  699.  
  700.   /// Set tree printing, to outputting the template difference in a
  701.   /// tree format.
  702.   void setPrintTemplateTree(bool Val) { PrintTemplateTree = Val; }
  703.   bool getPrintTemplateTree() { return PrintTemplateTree; }
  704.  
  705.   /// Set color printing, so the type diffing will inject color markers
  706.   /// into the output.
  707.   void setShowColors(bool Val) { ShowColors = Val; }
  708.   bool getShowColors() { return ShowColors; }
  709.  
  710.   /// Specify which overload candidates to show when overload resolution
  711.   /// fails.
  712.   ///
  713.   /// By default, we show all candidates.
  714.   void setShowOverloads(OverloadsShown Val) {
  715.     ShowOverloads = Val;
  716.   }
  717.   OverloadsShown getShowOverloads() const { return ShowOverloads; }
  718.  
  719.   /// When a call or operator fails, print out up to this many candidate
  720.   /// overloads as suggestions.
  721.   ///
  722.   /// With Ovl_Best, we set a high limit for the first nontrivial overload set
  723.   /// we print, and a lower limit for later sets.  This way the user has a
  724.   /// chance of diagnosing at least one callsite in their program without
  725.   /// having to recompile with -fshow-overloads=all.
  726.   unsigned getNumOverloadCandidatesToShow() const {
  727.     switch (getShowOverloads()) {
  728.     case Ovl_All:
  729.       // INT_MAX rather than UINT_MAX so that we don't have to think about the
  730.       // effect of implicit conversions on this value. In practice we'll never
  731.       // hit 2^31 candidates anyway.
  732.       return std::numeric_limits<int>::max();
  733.     case Ovl_Best:
  734.       return NumOverloadsToShow;
  735.     }
  736.     llvm_unreachable("invalid OverloadsShown kind");
  737.   }
  738.  
  739.   /// Call this after showing N overload candidates.  This influences the value
  740.   /// returned by later calls to getNumOverloadCandidatesToShow().
  741.   void overloadCandidatesShown(unsigned N) {
  742.     // Current heuristic: Start out with a large value for NumOverloadsToShow,
  743.     // and then once we print one nontrivially-large overload set, decrease it
  744.     // for future calls.
  745.     if (N > 4) {
  746.       NumOverloadsToShow = 4;
  747.     }
  748.   }
  749.  
  750.   /// Pretend that the last diagnostic issued was ignored, so any
  751.   /// subsequent notes will be suppressed, or restore a prior ignoring
  752.   /// state after ignoring some diagnostics and their notes, possibly in
  753.   /// the middle of another diagnostic.
  754.   ///
  755.   /// This can be used by clients who suppress diagnostics themselves.
  756.   void setLastDiagnosticIgnored(bool Ignored) {
  757.     if (LastDiagLevel == DiagnosticIDs::Fatal)
  758.       FatalErrorOccurred = true;
  759.     LastDiagLevel = Ignored ? DiagnosticIDs::Ignored : DiagnosticIDs::Warning;
  760.   }
  761.  
  762.   /// Determine whether the previous diagnostic was ignored. This can
  763.   /// be used by clients that want to determine whether notes attached to a
  764.   /// diagnostic will be suppressed.
  765.   bool isLastDiagnosticIgnored() const {
  766.     return LastDiagLevel == DiagnosticIDs::Ignored;
  767.   }
  768.  
  769.   /// Controls whether otherwise-unmapped extension diagnostics are
  770.   /// mapped onto ignore/warning/error.
  771.   ///
  772.   /// This corresponds to the GCC -pedantic and -pedantic-errors option.
  773.   void setExtensionHandlingBehavior(diag::Severity H) {
  774.     GetCurDiagState()->ExtBehavior = H;
  775.   }
  776.   diag::Severity getExtensionHandlingBehavior() const {
  777.     return GetCurDiagState()->ExtBehavior;
  778.   }
  779.  
  780.   /// Counter bumped when an __extension__  block is/ encountered.
  781.   ///
  782.   /// When non-zero, all extension diagnostics are entirely silenced, no
  783.   /// matter how they are mapped.
  784.   void IncrementAllExtensionsSilenced() { ++AllExtensionsSilenced; }
  785.   void DecrementAllExtensionsSilenced() { --AllExtensionsSilenced; }
  786.   bool hasAllExtensionsSilenced() { return AllExtensionsSilenced != 0; }
  787.  
  788.   /// This allows the client to specify that certain warnings are
  789.   /// ignored.
  790.   ///
  791.   /// Notes can never be mapped, errors can only be mapped to fatal, and
  792.   /// WARNINGs and EXTENSIONs can be mapped arbitrarily.
  793.   ///
  794.   /// \param Loc The source location that this change of diagnostic state should
  795.   /// take affect. It can be null if we are setting the latest state.
  796.   void setSeverity(diag::kind Diag, diag::Severity Map, SourceLocation Loc);
  797.  
  798.   /// Change an entire diagnostic group (e.g. "unknown-pragmas") to
  799.   /// have the specified mapping.
  800.   ///
  801.   /// \returns true (and ignores the request) if "Group" was unknown, false
  802.   /// otherwise.
  803.   ///
  804.   /// \param Flavor The flavor of group to affect. -Rfoo does not affect the
  805.   /// state of the -Wfoo group and vice versa.
  806.   ///
  807.   /// \param Loc The source location that this change of diagnostic state should
  808.   /// take affect. It can be null if we are setting the state from command-line.
  809.   bool setSeverityForGroup(diag::Flavor Flavor, StringRef Group,
  810.                            diag::Severity Map,
  811.                            SourceLocation Loc = SourceLocation());
  812.   bool setSeverityForGroup(diag::Flavor Flavor, diag::Group Group,
  813.                            diag::Severity Map,
  814.                            SourceLocation Loc = SourceLocation());
  815.  
  816.   /// Set the warning-as-error flag for the given diagnostic group.
  817.   ///
  818.   /// This function always only operates on the current diagnostic state.
  819.   ///
  820.   /// \returns True if the given group is unknown, false otherwise.
  821.   bool setDiagnosticGroupWarningAsError(StringRef Group, bool Enabled);
  822.  
  823.   /// Set the error-as-fatal flag for the given diagnostic group.
  824.   ///
  825.   /// This function always only operates on the current diagnostic state.
  826.   ///
  827.   /// \returns True if the given group is unknown, false otherwise.
  828.   bool setDiagnosticGroupErrorAsFatal(StringRef Group, bool Enabled);
  829.  
  830.   /// Add the specified mapping to all diagnostics of the specified
  831.   /// flavor.
  832.   ///
  833.   /// Mainly to be used by -Wno-everything to disable all warnings but allow
  834.   /// subsequent -W options to enable specific warnings.
  835.   void setSeverityForAll(diag::Flavor Flavor, diag::Severity Map,
  836.                          SourceLocation Loc = SourceLocation());
  837.  
  838.   bool hasErrorOccurred() const { return ErrorOccurred; }
  839.  
  840.   /// Errors that actually prevent compilation, not those that are
  841.   /// upgraded from a warning by -Werror.
  842.   bool hasUncompilableErrorOccurred() const {
  843.     return UncompilableErrorOccurred;
  844.   }
  845.   bool hasFatalErrorOccurred() const { return FatalErrorOccurred; }
  846.  
  847.   /// Determine whether any kind of unrecoverable error has occurred.
  848.   bool hasUnrecoverableErrorOccurred() const {
  849.     return FatalErrorOccurred || UnrecoverableErrorOccurred;
  850.   }
  851.  
  852.   unsigned getNumErrors() const { return NumErrors; }
  853.   unsigned getNumWarnings() const { return NumWarnings; }
  854.  
  855.   void setNumWarnings(unsigned NumWarnings) {
  856.     this->NumWarnings = NumWarnings;
  857.   }
  858.  
  859.   /// Return an ID for a diagnostic with the specified format string and
  860.   /// level.
  861.   ///
  862.   /// If this is the first request for this diagnostic, it is registered and
  863.   /// created, otherwise the existing ID is returned.
  864.   ///
  865.   /// \param FormatString A fixed diagnostic format string that will be hashed
  866.   /// and mapped to a unique DiagID.
  867.   template <unsigned N>
  868.   unsigned getCustomDiagID(Level L, const char (&FormatString)[N]) {
  869.     return Diags->getCustomDiagID((DiagnosticIDs::Level)L,
  870.                                   StringRef(FormatString, N - 1));
  871.   }
  872.  
  873.   /// Converts a diagnostic argument (as an intptr_t) into the string
  874.   /// that represents it.
  875.   void ConvertArgToString(ArgumentKind Kind, intptr_t Val,
  876.                           StringRef Modifier, StringRef Argument,
  877.                           ArrayRef<ArgumentValue> PrevArgs,
  878.                           SmallVectorImpl<char> &Output,
  879.                           ArrayRef<intptr_t> QualTypeVals) const {
  880.     ArgToStringFn(Kind, Val, Modifier, Argument, PrevArgs, Output,
  881.                   ArgToStringCookie, QualTypeVals);
  882.   }
  883.  
  884.   void SetArgToStringFn(ArgToStringFnTy Fn, void *Cookie) {
  885.     ArgToStringFn = Fn;
  886.     ArgToStringCookie = Cookie;
  887.   }
  888.  
  889.   /// Note that the prior diagnostic was emitted by some other
  890.   /// \c DiagnosticsEngine, and we may be attaching a note to that diagnostic.
  891.   void notePriorDiagnosticFrom(const DiagnosticsEngine &Other) {
  892.     LastDiagLevel = Other.LastDiagLevel;
  893.   }
  894.  
  895.   /// Reset the state of the diagnostic object to its initial configuration.
  896.   /// \param[in] soft - if true, doesn't reset the diagnostic mappings and state
  897.   void Reset(bool soft = false);
  898.  
  899.   //===--------------------------------------------------------------------===//
  900.   // DiagnosticsEngine classification and reporting interfaces.
  901.   //
  902.  
  903.   /// Determine whether the diagnostic is known to be ignored.
  904.   ///
  905.   /// This can be used to opportunistically avoid expensive checks when it's
  906.   /// known for certain that the diagnostic has been suppressed at the
  907.   /// specified location \p Loc.
  908.   ///
  909.   /// \param Loc The source location we are interested in finding out the
  910.   /// diagnostic state. Can be null in order to query the latest state.
  911.   bool isIgnored(unsigned DiagID, SourceLocation Loc) const {
  912.     return Diags->getDiagnosticSeverity(DiagID, Loc, *this) ==
  913.            diag::Severity::Ignored;
  914.   }
  915.  
  916.   /// Based on the way the client configured the DiagnosticsEngine
  917.   /// object, classify the specified diagnostic ID into a Level, consumable by
  918.   /// the DiagnosticConsumer.
  919.   ///
  920.   /// To preserve invariant assumptions, this function should not be used to
  921.   /// influence parse or semantic analysis actions. Instead consider using
  922.   /// \c isIgnored().
  923.   ///
  924.   /// \param Loc The source location we are interested in finding out the
  925.   /// diagnostic state. Can be null in order to query the latest state.
  926.   Level getDiagnosticLevel(unsigned DiagID, SourceLocation Loc) const {
  927.     return (Level)Diags->getDiagnosticLevel(DiagID, Loc, *this);
  928.   }
  929.  
  930.   /// Issue the message to the client.
  931.   ///
  932.   /// This actually returns an instance of DiagnosticBuilder which emits the
  933.   /// diagnostics (through @c ProcessDiag) when it is destroyed.
  934.   ///
  935.   /// \param DiagID A member of the @c diag::kind enum.
  936.   /// \param Loc Represents the source location associated with the diagnostic,
  937.   /// which can be an invalid location if no position information is available.
  938.   inline DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID);
  939.   inline DiagnosticBuilder Report(unsigned DiagID);
  940.  
  941.   void Report(const StoredDiagnostic &storedDiag);
  942.  
  943.   /// Determine whethere there is already a diagnostic in flight.
  944.   bool isDiagnosticInFlight() const {
  945.     return CurDiagID != std::numeric_limits<unsigned>::max();
  946.   }
  947.  
  948.   /// Set the "delayed" diagnostic that will be emitted once
  949.   /// the current diagnostic completes.
  950.   ///
  951.   ///  If a diagnostic is already in-flight but the front end must
  952.   ///  report a problem (e.g., with an inconsistent file system
  953.   ///  state), this routine sets a "delayed" diagnostic that will be
  954.   ///  emitted after the current diagnostic completes. This should
  955.   ///  only be used for fatal errors detected at inconvenient
  956.   ///  times. If emitting a delayed diagnostic causes a second delayed
  957.   ///  diagnostic to be introduced, that second delayed diagnostic
  958.   ///  will be ignored.
  959.   ///
  960.   /// \param DiagID The ID of the diagnostic being delayed.
  961.   ///
  962.   /// \param Arg1 A string argument that will be provided to the
  963.   /// diagnostic. A copy of this string will be stored in the
  964.   /// DiagnosticsEngine object itself.
  965.   ///
  966.   /// \param Arg2 A string argument that will be provided to the
  967.   /// diagnostic. A copy of this string will be stored in the
  968.   /// DiagnosticsEngine object itself.
  969.   ///
  970.   /// \param Arg3 A string argument that will be provided to the
  971.   /// diagnostic. A copy of this string will be stored in the
  972.   /// DiagnosticsEngine object itself.
  973.   void SetDelayedDiagnostic(unsigned DiagID, StringRef Arg1 = "",
  974.                             StringRef Arg2 = "", StringRef Arg3 = "");
  975.  
  976.   /// Clear out the current diagnostic.
  977.   void Clear() { CurDiagID = std::numeric_limits<unsigned>::max(); }
  978.  
  979.   /// Return the value associated with this diagnostic flag.
  980.   StringRef getFlagValue() const { return FlagValue; }
  981.  
  982. private:
  983.   // This is private state used by DiagnosticBuilder.  We put it here instead of
  984.   // in DiagnosticBuilder in order to keep DiagnosticBuilder a small lightweight
  985.   // object.  This implementation choice means that we can only have one
  986.   // diagnostic "in flight" at a time, but this seems to be a reasonable
  987.   // tradeoff to keep these objects small.  Assertions verify that only one
  988.   // diagnostic is in flight at a time.
  989.   friend class Diagnostic;
  990.   friend class DiagnosticBuilder;
  991.   friend class DiagnosticErrorTrap;
  992.   friend class DiagnosticIDs;
  993.   friend class PartialDiagnostic;
  994.  
  995.   /// Report the delayed diagnostic.
  996.   void ReportDelayed();
  997.  
  998.   /// The location of the current diagnostic that is in flight.
  999.   SourceLocation CurDiagLoc;
  1000.  
  1001.   /// The ID of the current diagnostic that is in flight.
  1002.   ///
  1003.   /// This is set to std::numeric_limits<unsigned>::max() when there is no
  1004.   /// diagnostic in flight.
  1005.   unsigned CurDiagID;
  1006.  
  1007.   enum {
  1008.     /// The maximum number of arguments we can hold.
  1009.     ///
  1010.     /// We currently only support up to 10 arguments (%0-%9).  A single
  1011.     /// diagnostic with more than that almost certainly has to be simplified
  1012.     /// anyway.
  1013.     MaxArguments = DiagnosticStorage::MaxArguments,
  1014.   };
  1015.  
  1016.   DiagnosticStorage DiagStorage;
  1017.  
  1018.   DiagnosticMapping makeUserMapping(diag::Severity Map, SourceLocation L) {
  1019.     bool isPragma = L.isValid();
  1020.     DiagnosticMapping Mapping =
  1021.         DiagnosticMapping::Make(Map, /*IsUser=*/true, isPragma);
  1022.  
  1023.     // If this is a pragma mapping, then set the diagnostic mapping flags so
  1024.     // that we override command line options.
  1025.     if (isPragma) {
  1026.       Mapping.setNoWarningAsError(true);
  1027.       Mapping.setNoErrorAsFatal(true);
  1028.     }
  1029.  
  1030.     return Mapping;
  1031.   }
  1032.  
  1033.   /// Used to report a diagnostic that is finally fully formed.
  1034.   ///
  1035.   /// \returns true if the diagnostic was emitted, false if it was suppressed.
  1036.   bool ProcessDiag() {
  1037.     return Diags->ProcessDiag(*this);
  1038.   }
  1039.  
  1040.   /// @name Diagnostic Emission
  1041.   /// @{
  1042. protected:
  1043.   friend class ASTReader;
  1044.   friend class ASTWriter;
  1045.  
  1046.   // Sema requires access to the following functions because the current design
  1047.   // of SFINAE requires it to use its own SemaDiagnosticBuilder, which needs to
  1048.   // access us directly to ensure we minimize the emitted code for the common
  1049.   // Sema::Diag() patterns.
  1050.   friend class Sema;
  1051.  
  1052.   /// Emit the current diagnostic and clear the diagnostic state.
  1053.   ///
  1054.   /// \param Force Emit the diagnostic regardless of suppression settings.
  1055.   bool EmitCurrentDiagnostic(bool Force = false);
  1056.  
  1057.   unsigned getCurrentDiagID() const { return CurDiagID; }
  1058.  
  1059.   SourceLocation getCurrentDiagLoc() const { return CurDiagLoc; }
  1060.  
  1061.   /// @}
  1062. };
  1063.  
  1064. /// RAII class that determines when any errors have occurred
  1065. /// between the time the instance was created and the time it was
  1066. /// queried.
  1067. ///
  1068. /// Note that you almost certainly do not want to use this. It's usually
  1069. /// meaningless to ask whether a particular scope triggered an error message,
  1070. /// because error messages outside that scope can mark things invalid (or cause
  1071. /// us to reach an error limit), which can suppress errors within that scope.
  1072. class DiagnosticErrorTrap {
  1073.   DiagnosticsEngine &Diag;
  1074.   unsigned NumErrors;
  1075.   unsigned NumUnrecoverableErrors;
  1076.  
  1077. public:
  1078.   explicit DiagnosticErrorTrap(DiagnosticsEngine &Diag)
  1079.       : Diag(Diag) { reset(); }
  1080.  
  1081.   /// Determine whether any errors have occurred since this
  1082.   /// object instance was created.
  1083.   bool hasErrorOccurred() const {
  1084.     return Diag.TrapNumErrorsOccurred > NumErrors;
  1085.   }
  1086.  
  1087.   /// Determine whether any unrecoverable errors have occurred since this
  1088.   /// object instance was created.
  1089.   bool hasUnrecoverableErrorOccurred() const {
  1090.     return Diag.TrapNumUnrecoverableErrorsOccurred > NumUnrecoverableErrors;
  1091.   }
  1092.  
  1093.   /// Set to initial state of "no errors occurred".
  1094.   void reset() {
  1095.     NumErrors = Diag.TrapNumErrorsOccurred;
  1096.     NumUnrecoverableErrors = Diag.TrapNumUnrecoverableErrorsOccurred;
  1097.   }
  1098. };
  1099.  
  1100. /// The streaming interface shared between DiagnosticBuilder and
  1101. /// PartialDiagnostic. This class is not intended to be constructed directly
  1102. /// but only as base class of DiagnosticBuilder and PartialDiagnostic builder.
  1103. ///
  1104. /// Any new type of argument accepted by DiagnosticBuilder and PartialDiagnostic
  1105. /// should be implemented as a '<<' operator of StreamingDiagnostic, e.g.
  1106. ///
  1107. /// const StreamingDiagnostic&
  1108. /// operator<<(const StreamingDiagnostic&, NewArgType);
  1109. ///
  1110. class StreamingDiagnostic {
  1111. public:
  1112.   /// An allocator for DiagnosticStorage objects, which uses a small cache to
  1113.   /// objects, used to reduce malloc()/free() traffic for partial diagnostics.
  1114.   class DiagStorageAllocator {
  1115.     static const unsigned NumCached = 16;
  1116.     DiagnosticStorage Cached[NumCached];
  1117.     DiagnosticStorage *FreeList[NumCached];
  1118.     unsigned NumFreeListEntries;
  1119.  
  1120.   public:
  1121.     DiagStorageAllocator();
  1122.     ~DiagStorageAllocator();
  1123.  
  1124.     /// Allocate new storage.
  1125.     DiagnosticStorage *Allocate() {
  1126.       if (NumFreeListEntries == 0)
  1127.         return new DiagnosticStorage;
  1128.  
  1129.       DiagnosticStorage *Result = FreeList[--NumFreeListEntries];
  1130.       Result->NumDiagArgs = 0;
  1131.       Result->DiagRanges.clear();
  1132.       Result->FixItHints.clear();
  1133.       return Result;
  1134.     }
  1135.  
  1136.     /// Free the given storage object.
  1137.     void Deallocate(DiagnosticStorage *S) {
  1138.       if (S >= Cached && S <= Cached + NumCached) {
  1139.         FreeList[NumFreeListEntries++] = S;
  1140.         return;
  1141.       }
  1142.  
  1143.       delete S;
  1144.     }
  1145.   };
  1146.  
  1147. protected:
  1148.   mutable DiagnosticStorage *DiagStorage = nullptr;
  1149.  
  1150.   /// Allocator used to allocate storage for this diagnostic.
  1151.   DiagStorageAllocator *Allocator = nullptr;
  1152.  
  1153. public:
  1154.   /// Retrieve storage for this particular diagnostic.
  1155.   DiagnosticStorage *getStorage() const {
  1156.     if (DiagStorage)
  1157.       return DiagStorage;
  1158.  
  1159.     assert(Allocator);
  1160.     DiagStorage = Allocator->Allocate();
  1161.     return DiagStorage;
  1162.   }
  1163.  
  1164.   void freeStorage() {
  1165.     if (!DiagStorage)
  1166.       return;
  1167.  
  1168.     // The hot path for PartialDiagnostic is when we just used it to wrap an ID
  1169.     // (typically so we have the flexibility of passing a more complex
  1170.     // diagnostic into the callee, but that does not commonly occur).
  1171.     //
  1172.     // Split this out into a slow function for silly compilers (*cough*) which
  1173.     // can't do decent partial inlining.
  1174.     freeStorageSlow();
  1175.   }
  1176.  
  1177.   void freeStorageSlow() {
  1178.     if (!Allocator)
  1179.       return;
  1180.     Allocator->Deallocate(DiagStorage);
  1181.     DiagStorage = nullptr;
  1182.   }
  1183.  
  1184.   void AddTaggedVal(uint64_t V, DiagnosticsEngine::ArgumentKind Kind) const {
  1185.     if (!DiagStorage)
  1186.       DiagStorage = getStorage();
  1187.  
  1188.     assert(DiagStorage->NumDiagArgs < DiagnosticStorage::MaxArguments &&
  1189.            "Too many arguments to diagnostic!");
  1190.     DiagStorage->DiagArgumentsKind[DiagStorage->NumDiagArgs] = Kind;
  1191.     DiagStorage->DiagArgumentsVal[DiagStorage->NumDiagArgs++] = V;
  1192.   }
  1193.  
  1194.   void AddString(StringRef V) const {
  1195.     if (!DiagStorage)
  1196.       DiagStorage = getStorage();
  1197.  
  1198.     assert(DiagStorage->NumDiagArgs < DiagnosticStorage::MaxArguments &&
  1199.            "Too many arguments to diagnostic!");
  1200.     DiagStorage->DiagArgumentsKind[DiagStorage->NumDiagArgs] =
  1201.         DiagnosticsEngine::ak_std_string;
  1202.     DiagStorage->DiagArgumentsStr[DiagStorage->NumDiagArgs++] = std::string(V);
  1203.   }
  1204.  
  1205.   void AddSourceRange(const CharSourceRange &R) const {
  1206.     if (!DiagStorage)
  1207.       DiagStorage = getStorage();
  1208.  
  1209.     DiagStorage->DiagRanges.push_back(R);
  1210.   }
  1211.  
  1212.   void AddFixItHint(const FixItHint &Hint) const {
  1213.     if (Hint.isNull())
  1214.       return;
  1215.  
  1216.     if (!DiagStorage)
  1217.       DiagStorage = getStorage();
  1218.  
  1219.     DiagStorage->FixItHints.push_back(Hint);
  1220.   }
  1221.  
  1222.   /// Conversion of StreamingDiagnostic to bool always returns \c true.
  1223.   ///
  1224.   /// This allows is to be used in boolean error contexts (where \c true is
  1225.   /// used to indicate that an error has occurred), like:
  1226.   /// \code
  1227.   /// return Diag(...);
  1228.   /// \endcode
  1229.   operator bool() const { return true; }
  1230.  
  1231. protected:
  1232.   StreamingDiagnostic() = default;
  1233.  
  1234.   /// Construct with an external storage not owned by itself. The allocator
  1235.   /// is a null pointer in this case.
  1236.   explicit StreamingDiagnostic(DiagnosticStorage *Storage)
  1237.       : DiagStorage(Storage) {}
  1238.  
  1239.   /// Construct with a storage allocator which will manage the storage. The
  1240.   /// allocator is not a null pointer in this case.
  1241.   explicit StreamingDiagnostic(DiagStorageAllocator &Alloc)
  1242.       : Allocator(&Alloc) {}
  1243.  
  1244.   StreamingDiagnostic(const StreamingDiagnostic &Diag) = default;
  1245.   StreamingDiagnostic(StreamingDiagnostic &&Diag) = default;
  1246.  
  1247.   ~StreamingDiagnostic() { freeStorage(); }
  1248. };
  1249.  
  1250. //===----------------------------------------------------------------------===//
  1251. // DiagnosticBuilder
  1252. //===----------------------------------------------------------------------===//
  1253.  
  1254. /// A little helper class used to produce diagnostics.
  1255. ///
  1256. /// This is constructed by the DiagnosticsEngine::Report method, and
  1257. /// allows insertion of extra information (arguments and source ranges) into
  1258. /// the currently "in flight" diagnostic.  When the temporary for the builder
  1259. /// is destroyed, the diagnostic is issued.
  1260. ///
  1261. /// Note that many of these will be created as temporary objects (many call
  1262. /// sites), so we want them to be small and we never want their address taken.
  1263. /// This ensures that compilers with somewhat reasonable optimizers will promote
  1264. /// the common fields to registers, eliminating increments of the NumArgs field,
  1265. /// for example.
  1266. class DiagnosticBuilder : public StreamingDiagnostic {
  1267.   friend class DiagnosticsEngine;
  1268.   friend class PartialDiagnostic;
  1269.  
  1270.   mutable DiagnosticsEngine *DiagObj = nullptr;
  1271.  
  1272.   /// Status variable indicating if this diagnostic is still active.
  1273.   ///
  1274.   // NOTE: This field is redundant with DiagObj (IsActive iff (DiagObj == 0)),
  1275.   // but LLVM is not currently smart enough to eliminate the null check that
  1276.   // Emit() would end up with if we used that as our status variable.
  1277.   mutable bool IsActive = false;
  1278.  
  1279.   /// Flag indicating that this diagnostic is being emitted via a
  1280.   /// call to ForceEmit.
  1281.   mutable bool IsForceEmit = false;
  1282.  
  1283.   DiagnosticBuilder() = default;
  1284.  
  1285.   explicit DiagnosticBuilder(DiagnosticsEngine *diagObj)
  1286.       : StreamingDiagnostic(&diagObj->DiagStorage), DiagObj(diagObj),
  1287.         IsActive(true) {
  1288.     assert(diagObj && "DiagnosticBuilder requires a valid DiagnosticsEngine!");
  1289.     assert(DiagStorage &&
  1290.            "DiagnosticBuilder requires a valid DiagnosticStorage!");
  1291.     DiagStorage->NumDiagArgs = 0;
  1292.     DiagStorage->DiagRanges.clear();
  1293.     DiagStorage->FixItHints.clear();
  1294.   }
  1295.  
  1296. protected:
  1297.   /// Clear out the current diagnostic.
  1298.   void Clear() const {
  1299.     DiagObj = nullptr;
  1300.     IsActive = false;
  1301.     IsForceEmit = false;
  1302.   }
  1303.  
  1304.   /// Determine whether this diagnostic is still active.
  1305.   bool isActive() const { return IsActive; }
  1306.  
  1307.   /// Force the diagnostic builder to emit the diagnostic now.
  1308.   ///
  1309.   /// Once this function has been called, the DiagnosticBuilder object
  1310.   /// should not be used again before it is destroyed.
  1311.   ///
  1312.   /// \returns true if a diagnostic was emitted, false if the
  1313.   /// diagnostic was suppressed.
  1314.   bool Emit() {
  1315.     // If this diagnostic is inactive, then its soul was stolen by the copy ctor
  1316.     // (or by a subclass, as in SemaDiagnosticBuilder).
  1317.     if (!isActive()) return false;
  1318.  
  1319.     // Process the diagnostic.
  1320.     bool Result = DiagObj->EmitCurrentDiagnostic(IsForceEmit);
  1321.  
  1322.     // This diagnostic is dead.
  1323.     Clear();
  1324.  
  1325.     return Result;
  1326.   }
  1327.  
  1328. public:
  1329.   /// Copy constructor.  When copied, this "takes" the diagnostic info from the
  1330.   /// input and neuters it.
  1331.   DiagnosticBuilder(const DiagnosticBuilder &D) : StreamingDiagnostic() {
  1332.     DiagObj = D.DiagObj;
  1333.     DiagStorage = D.DiagStorage;
  1334.     IsActive = D.IsActive;
  1335.     IsForceEmit = D.IsForceEmit;
  1336.     D.Clear();
  1337.   }
  1338.  
  1339.   template <typename T> const DiagnosticBuilder &operator<<(const T &V) const {
  1340.     assert(isActive() && "Clients must not add to cleared diagnostic!");
  1341.     const StreamingDiagnostic &DB = *this;
  1342.     DB << V;
  1343.     return *this;
  1344.   }
  1345.  
  1346.   // It is necessary to limit this to rvalue reference to avoid calling this
  1347.   // function with a bitfield lvalue argument since non-const reference to
  1348.   // bitfield is not allowed.
  1349.   template <typename T,
  1350.             typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
  1351.   const DiagnosticBuilder &operator<<(T &&V) const {
  1352.     assert(isActive() && "Clients must not add to cleared diagnostic!");
  1353.     const StreamingDiagnostic &DB = *this;
  1354.     DB << std::move(V);
  1355.     return *this;
  1356.   }
  1357.  
  1358.   DiagnosticBuilder &operator=(const DiagnosticBuilder &) = delete;
  1359.  
  1360.   /// Emits the diagnostic.
  1361.   ~DiagnosticBuilder() { Emit(); }
  1362.  
  1363.   /// Forces the diagnostic to be emitted.
  1364.   const DiagnosticBuilder &setForceEmit() const {
  1365.     IsForceEmit = true;
  1366.     return *this;
  1367.   }
  1368.  
  1369.   void addFlagValue(StringRef V) const { DiagObj->FlagValue = std::string(V); }
  1370. };
  1371.  
  1372. struct AddFlagValue {
  1373.   StringRef Val;
  1374.  
  1375.   explicit AddFlagValue(StringRef V) : Val(V) {}
  1376. };
  1377.  
  1378. /// Register a value for the flag in the current diagnostic. This
  1379. /// value will be shown as the suffix "=value" after the flag name. It is
  1380. /// useful in cases where the diagnostic flag accepts values (e.g.,
  1381. /// -Rpass or -Wframe-larger-than).
  1382. inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
  1383.                                            const AddFlagValue V) {
  1384.   DB.addFlagValue(V.Val);
  1385.   return DB;
  1386. }
  1387.  
  1388. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1389.                                              StringRef S) {
  1390.   DB.AddString(S);
  1391.   return DB;
  1392. }
  1393.  
  1394. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1395.                                              const char *Str) {
  1396.   DB.AddTaggedVal(reinterpret_cast<intptr_t>(Str),
  1397.                   DiagnosticsEngine::ak_c_string);
  1398.   return DB;
  1399. }
  1400.  
  1401. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1402.                                              int I) {
  1403.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_sint);
  1404.   return DB;
  1405. }
  1406.  
  1407. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1408.                                              long I) {
  1409.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_sint);
  1410.   return DB;
  1411. }
  1412.  
  1413. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1414.                                              long long I) {
  1415.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_sint);
  1416.   return DB;
  1417. }
  1418.  
  1419. // We use enable_if here to prevent that this overload is selected for
  1420. // pointers or other arguments that are implicitly convertible to bool.
  1421. template <typename T>
  1422. inline std::enable_if_t<std::is_same<T, bool>::value,
  1423.                         const StreamingDiagnostic &>
  1424. operator<<(const StreamingDiagnostic &DB, T I) {
  1425.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_sint);
  1426.   return DB;
  1427. }
  1428.  
  1429. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1430.                                              unsigned I) {
  1431.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_uint);
  1432.   return DB;
  1433. }
  1434.  
  1435. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1436.                                              unsigned long I) {
  1437.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_uint);
  1438.   return DB;
  1439. }
  1440.  
  1441. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1442.                                              unsigned long long I) {
  1443.   DB.AddTaggedVal(I, DiagnosticsEngine::ak_uint);
  1444.   return DB;
  1445. }
  1446.  
  1447. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1448.                                              tok::TokenKind I) {
  1449.   DB.AddTaggedVal(static_cast<unsigned>(I), DiagnosticsEngine::ak_tokenkind);
  1450.   return DB;
  1451. }
  1452.  
  1453. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1454.                                              const IdentifierInfo *II) {
  1455.   DB.AddTaggedVal(reinterpret_cast<intptr_t>(II),
  1456.                   DiagnosticsEngine::ak_identifierinfo);
  1457.   return DB;
  1458. }
  1459.  
  1460. // Adds a DeclContext to the diagnostic. The enable_if template magic is here
  1461. // so that we only match those arguments that are (statically) DeclContexts;
  1462. // other arguments that derive from DeclContext (e.g., RecordDecls) will not
  1463. // match.
  1464. template <typename T>
  1465. inline std::enable_if_t<
  1466.     std::is_same<std::remove_const_t<T>, DeclContext>::value,
  1467.     const StreamingDiagnostic &>
  1468. operator<<(const StreamingDiagnostic &DB, T *DC) {
  1469.   DB.AddTaggedVal(reinterpret_cast<intptr_t>(DC),
  1470.                   DiagnosticsEngine::ak_declcontext);
  1471.   return DB;
  1472. }
  1473.  
  1474. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1475.                                              SourceLocation L) {
  1476.   DB.AddSourceRange(CharSourceRange::getTokenRange(L));
  1477.   return DB;
  1478. }
  1479.  
  1480. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1481.                                              SourceRange R) {
  1482.   DB.AddSourceRange(CharSourceRange::getTokenRange(R));
  1483.   return DB;
  1484. }
  1485.  
  1486. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1487.                                              ArrayRef<SourceRange> Ranges) {
  1488.   for (SourceRange R : Ranges)
  1489.     DB.AddSourceRange(CharSourceRange::getTokenRange(R));
  1490.   return DB;
  1491. }
  1492.  
  1493. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1494.                                              const CharSourceRange &R) {
  1495.   DB.AddSourceRange(R);
  1496.   return DB;
  1497. }
  1498.  
  1499. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1500.                                              const FixItHint &Hint) {
  1501.   DB.AddFixItHint(Hint);
  1502.   return DB;
  1503. }
  1504.  
  1505. inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1506.                                              ArrayRef<FixItHint> Hints) {
  1507.   for (const FixItHint &Hint : Hints)
  1508.     DB.AddFixItHint(Hint);
  1509.   return DB;
  1510. }
  1511.  
  1512. inline const StreamingDiagnostic &
  1513. operator<<(const StreamingDiagnostic &DB,
  1514.            const std::optional<SourceRange> &Opt) {
  1515.   if (Opt)
  1516.     DB << *Opt;
  1517.   return DB;
  1518. }
  1519.  
  1520. inline const StreamingDiagnostic &
  1521. operator<<(const StreamingDiagnostic &DB,
  1522.            const std::optional<CharSourceRange> &Opt) {
  1523.   if (Opt)
  1524.     DB << *Opt;
  1525.   return DB;
  1526. }
  1527.  
  1528. inline const StreamingDiagnostic &
  1529. operator<<(const StreamingDiagnostic &DB, const std::optional<FixItHint> &Opt) {
  1530.   if (Opt)
  1531.     DB << *Opt;
  1532.   return DB;
  1533. }
  1534.  
  1535. /// A nullability kind paired with a bit indicating whether it used a
  1536. /// context-sensitive keyword.
  1537. using DiagNullabilityKind = std::pair<NullabilityKind, bool>;
  1538.  
  1539. const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1540.                                       DiagNullabilityKind nullability);
  1541.  
  1542. inline DiagnosticBuilder DiagnosticsEngine::Report(SourceLocation Loc,
  1543.                                                    unsigned DiagID) {
  1544.   assert(CurDiagID == std::numeric_limits<unsigned>::max() &&
  1545.          "Multiple diagnostics in flight at once!");
  1546.   CurDiagLoc = Loc;
  1547.   CurDiagID = DiagID;
  1548.   FlagValue.clear();
  1549.   return DiagnosticBuilder(this);
  1550. }
  1551.  
  1552. const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
  1553.                                       llvm::Error &&E);
  1554.  
  1555. inline DiagnosticBuilder DiagnosticsEngine::Report(unsigned DiagID) {
  1556.   return Report(SourceLocation(), DiagID);
  1557. }
  1558.  
  1559. //===----------------------------------------------------------------------===//
  1560. // Diagnostic
  1561. //===----------------------------------------------------------------------===//
  1562.  
  1563. /// A little helper class (which is basically a smart pointer that forwards
  1564. /// info from DiagnosticsEngine) that allows clients to enquire about the
  1565. /// currently in-flight diagnostic.
  1566. class Diagnostic {
  1567.   const DiagnosticsEngine *DiagObj;
  1568.   StringRef StoredDiagMessage;
  1569.  
  1570. public:
  1571.   explicit Diagnostic(const DiagnosticsEngine *DO) : DiagObj(DO) {}
  1572.   Diagnostic(const DiagnosticsEngine *DO, StringRef storedDiagMessage)
  1573.       : DiagObj(DO), StoredDiagMessage(storedDiagMessage) {}
  1574.  
  1575.   const DiagnosticsEngine *getDiags() const { return DiagObj; }
  1576.   unsigned getID() const { return DiagObj->CurDiagID; }
  1577.   const SourceLocation &getLocation() const { return DiagObj->CurDiagLoc; }
  1578.   bool hasSourceManager() const { return DiagObj->hasSourceManager(); }
  1579.   SourceManager &getSourceManager() const { return DiagObj->getSourceManager();}
  1580.  
  1581.   unsigned getNumArgs() const { return DiagObj->DiagStorage.NumDiagArgs; }
  1582.  
  1583.   /// Return the kind of the specified index.
  1584.   ///
  1585.   /// Based on the kind of argument, the accessors below can be used to get
  1586.   /// the value.
  1587.   ///
  1588.   /// \pre Idx < getNumArgs()
  1589.   DiagnosticsEngine::ArgumentKind getArgKind(unsigned Idx) const {
  1590.     assert(Idx < getNumArgs() && "Argument index out of range!");
  1591.     return (DiagnosticsEngine::ArgumentKind)
  1592.         DiagObj->DiagStorage.DiagArgumentsKind[Idx];
  1593.   }
  1594.  
  1595.   /// Return the provided argument string specified by \p Idx.
  1596.   /// \pre getArgKind(Idx) == DiagnosticsEngine::ak_std_string
  1597.   const std::string &getArgStdStr(unsigned Idx) const {
  1598.     assert(getArgKind(Idx) == DiagnosticsEngine::ak_std_string &&
  1599.            "invalid argument accessor!");
  1600.     return DiagObj->DiagStorage.DiagArgumentsStr[Idx];
  1601.   }
  1602.  
  1603.   /// Return the specified C string argument.
  1604.   /// \pre getArgKind(Idx) == DiagnosticsEngine::ak_c_string
  1605.   const char *getArgCStr(unsigned Idx) const {
  1606.     assert(getArgKind(Idx) == DiagnosticsEngine::ak_c_string &&
  1607.            "invalid argument accessor!");
  1608.     return reinterpret_cast<const char *>(
  1609.         DiagObj->DiagStorage.DiagArgumentsVal[Idx]);
  1610.   }
  1611.  
  1612.   /// Return the specified signed integer argument.
  1613.   /// \pre getArgKind(Idx) == DiagnosticsEngine::ak_sint
  1614.   int64_t getArgSInt(unsigned Idx) const {
  1615.     assert(getArgKind(Idx) == DiagnosticsEngine::ak_sint &&
  1616.            "invalid argument accessor!");
  1617.     return (int64_t)DiagObj->DiagStorage.DiagArgumentsVal[Idx];
  1618.   }
  1619.  
  1620.   /// Return the specified unsigned integer argument.
  1621.   /// \pre getArgKind(Idx) == DiagnosticsEngine::ak_uint
  1622.   uint64_t getArgUInt(unsigned Idx) const {
  1623.     assert(getArgKind(Idx) == DiagnosticsEngine::ak_uint &&
  1624.            "invalid argument accessor!");
  1625.     return DiagObj->DiagStorage.DiagArgumentsVal[Idx];
  1626.   }
  1627.  
  1628.   /// Return the specified IdentifierInfo argument.
  1629.   /// \pre getArgKind(Idx) == DiagnosticsEngine::ak_identifierinfo
  1630.   const IdentifierInfo *getArgIdentifier(unsigned Idx) const {
  1631.     assert(getArgKind(Idx) == DiagnosticsEngine::ak_identifierinfo &&
  1632.            "invalid argument accessor!");
  1633.     return reinterpret_cast<IdentifierInfo *>(
  1634.         DiagObj->DiagStorage.DiagArgumentsVal[Idx]);
  1635.   }
  1636.  
  1637.   /// Return the specified non-string argument in an opaque form.
  1638.   /// \pre getArgKind(Idx) != DiagnosticsEngine::ak_std_string
  1639.   uint64_t getRawArg(unsigned Idx) const {
  1640.     assert(getArgKind(Idx) != DiagnosticsEngine::ak_std_string &&
  1641.            "invalid argument accessor!");
  1642.     return DiagObj->DiagStorage.DiagArgumentsVal[Idx];
  1643.   }
  1644.  
  1645.   /// Return the number of source ranges associated with this diagnostic.
  1646.   unsigned getNumRanges() const {
  1647.     return DiagObj->DiagStorage.DiagRanges.size();
  1648.   }
  1649.  
  1650.   /// \pre Idx < getNumRanges()
  1651.   const CharSourceRange &getRange(unsigned Idx) const {
  1652.     assert(Idx < getNumRanges() && "Invalid diagnostic range index!");
  1653.     return DiagObj->DiagStorage.DiagRanges[Idx];
  1654.   }
  1655.  
  1656.   /// Return an array reference for this diagnostic's ranges.
  1657.   ArrayRef<CharSourceRange> getRanges() const {
  1658.     return DiagObj->DiagStorage.DiagRanges;
  1659.   }
  1660.  
  1661.   unsigned getNumFixItHints() const {
  1662.     return DiagObj->DiagStorage.FixItHints.size();
  1663.   }
  1664.  
  1665.   const FixItHint &getFixItHint(unsigned Idx) const {
  1666.     assert(Idx < getNumFixItHints() && "Invalid index!");
  1667.     return DiagObj->DiagStorage.FixItHints[Idx];
  1668.   }
  1669.  
  1670.   ArrayRef<FixItHint> getFixItHints() const {
  1671.     return DiagObj->DiagStorage.FixItHints;
  1672.   }
  1673.  
  1674.   /// Format this diagnostic into a string, substituting the
  1675.   /// formal arguments into the %0 slots.
  1676.   ///
  1677.   /// The result is appended onto the \p OutStr array.
  1678.   void FormatDiagnostic(SmallVectorImpl<char> &OutStr) const;
  1679.  
  1680.   /// Format the given format-string into the output buffer using the
  1681.   /// arguments stored in this diagnostic.
  1682.   void FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
  1683.                         SmallVectorImpl<char> &OutStr) const;
  1684. };
  1685.  
  1686. /**
  1687.  * Represents a diagnostic in a form that can be retained until its
  1688.  * corresponding source manager is destroyed.
  1689.  */
  1690. class StoredDiagnostic {
  1691.   unsigned ID;
  1692.   DiagnosticsEngine::Level Level;
  1693.   FullSourceLoc Loc;
  1694.   std::string Message;
  1695.   std::vector<CharSourceRange> Ranges;
  1696.   std::vector<FixItHint> FixIts;
  1697.  
  1698. public:
  1699.   StoredDiagnostic() = default;
  1700.   StoredDiagnostic(DiagnosticsEngine::Level Level, const Diagnostic &Info);
  1701.   StoredDiagnostic(DiagnosticsEngine::Level Level, unsigned ID,
  1702.                    StringRef Message);
  1703.   StoredDiagnostic(DiagnosticsEngine::Level Level, unsigned ID,
  1704.                    StringRef Message, FullSourceLoc Loc,
  1705.                    ArrayRef<CharSourceRange> Ranges,
  1706.                    ArrayRef<FixItHint> Fixits);
  1707.  
  1708.   /// Evaluates true when this object stores a diagnostic.
  1709.   explicit operator bool() const { return !Message.empty(); }
  1710.  
  1711.   unsigned getID() const { return ID; }
  1712.   DiagnosticsEngine::Level getLevel() const { return Level; }
  1713.   const FullSourceLoc &getLocation() const { return Loc; }
  1714.   StringRef getMessage() const { return Message; }
  1715.  
  1716.   void setLocation(FullSourceLoc Loc) { this->Loc = Loc; }
  1717.  
  1718.   using range_iterator = std::vector<CharSourceRange>::const_iterator;
  1719.  
  1720.   range_iterator range_begin() const { return Ranges.begin(); }
  1721.   range_iterator range_end() const { return Ranges.end(); }
  1722.   unsigned range_size() const { return Ranges.size(); }
  1723.  
  1724.   ArrayRef<CharSourceRange> getRanges() const { return llvm::ArrayRef(Ranges); }
  1725.  
  1726.   using fixit_iterator = std::vector<FixItHint>::const_iterator;
  1727.  
  1728.   fixit_iterator fixit_begin() const { return FixIts.begin(); }
  1729.   fixit_iterator fixit_end() const { return FixIts.end(); }
  1730.   unsigned fixit_size() const { return FixIts.size(); }
  1731.  
  1732.   ArrayRef<FixItHint> getFixIts() const { return llvm::ArrayRef(FixIts); }
  1733. };
  1734.  
  1735. // Simple debug printing of StoredDiagnostic.
  1736. llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const StoredDiagnostic &);
  1737.  
  1738. /// Abstract interface, implemented by clients of the front-end, which
  1739. /// formats and prints fully processed diagnostics.
  1740. class DiagnosticConsumer {
  1741. protected:
  1742.   unsigned NumWarnings = 0;       ///< Number of warnings reported
  1743.   unsigned NumErrors = 0;         ///< Number of errors reported
  1744.  
  1745. public:
  1746.   DiagnosticConsumer() = default;
  1747.   virtual ~DiagnosticConsumer();
  1748.  
  1749.   unsigned getNumErrors() const { return NumErrors; }
  1750.   unsigned getNumWarnings() const { return NumWarnings; }
  1751.   virtual void clear() { NumWarnings = NumErrors = 0; }
  1752.  
  1753.   /// Callback to inform the diagnostic client that processing
  1754.   /// of a source file is beginning.
  1755.   ///
  1756.   /// Note that diagnostics may be emitted outside the processing of a source
  1757.   /// file, for example during the parsing of command line options. However,
  1758.   /// diagnostics with source range information are required to only be emitted
  1759.   /// in between BeginSourceFile() and EndSourceFile().
  1760.   ///
  1761.   /// \param LangOpts The language options for the source file being processed.
  1762.   /// \param PP The preprocessor object being used for the source; this is
  1763.   /// optional, e.g., it may not be present when processing AST source files.
  1764.   virtual void BeginSourceFile(const LangOptions &LangOpts,
  1765.                                const Preprocessor *PP = nullptr) {}
  1766.  
  1767.   /// Callback to inform the diagnostic client that processing
  1768.   /// of a source file has ended.
  1769.   ///
  1770.   /// The diagnostic client should assume that any objects made available via
  1771.   /// BeginSourceFile() are inaccessible.
  1772.   virtual void EndSourceFile() {}
  1773.  
  1774.   /// Callback to inform the diagnostic client that processing of all
  1775.   /// source files has ended.
  1776.   virtual void finish() {}
  1777.  
  1778.   /// Indicates whether the diagnostics handled by this
  1779.   /// DiagnosticConsumer should be included in the number of diagnostics
  1780.   /// reported by DiagnosticsEngine.
  1781.   ///
  1782.   /// The default implementation returns true.
  1783.   virtual bool IncludeInDiagnosticCounts() const;
  1784.  
  1785.   /// Handle this diagnostic, reporting it to the user or
  1786.   /// capturing it to a log as needed.
  1787.   ///
  1788.   /// The default implementation just keeps track of the total number of
  1789.   /// warnings and errors.
  1790.   virtual void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
  1791.                                 const Diagnostic &Info);
  1792. };
  1793.  
  1794. /// A diagnostic client that ignores all diagnostics.
  1795. class IgnoringDiagConsumer : public DiagnosticConsumer {
  1796.   virtual void anchor();
  1797.  
  1798.   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
  1799.                         const Diagnostic &Info) override {
  1800.     // Just ignore it.
  1801.   }
  1802. };
  1803.  
  1804. /// Diagnostic consumer that forwards diagnostics along to an
  1805. /// existing, already-initialized diagnostic consumer.
  1806. ///
  1807. class ForwardingDiagnosticConsumer : public DiagnosticConsumer {
  1808.   DiagnosticConsumer &Target;
  1809.  
  1810. public:
  1811.   ForwardingDiagnosticConsumer(DiagnosticConsumer &Target) : Target(Target) {}
  1812.   ~ForwardingDiagnosticConsumer() override;
  1813.  
  1814.   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
  1815.                         const Diagnostic &Info) override;
  1816.   void clear() override;
  1817.  
  1818.   bool IncludeInDiagnosticCounts() const override;
  1819. };
  1820.  
  1821. // Struct used for sending info about how a type should be printed.
  1822. struct TemplateDiffTypes {
  1823.   intptr_t FromType;
  1824.   intptr_t ToType;
  1825.   unsigned PrintTree : 1;
  1826.   unsigned PrintFromType : 1;
  1827.   unsigned ElideType : 1;
  1828.   unsigned ShowColors : 1;
  1829.  
  1830.   // The printer sets this variable to true if the template diff was used.
  1831.   unsigned TemplateDiffUsed : 1;
  1832. };
  1833.  
  1834. /// Special character that the diagnostic printer will use to toggle the bold
  1835. /// attribute.  The character itself will be not be printed.
  1836. const char ToggleHighlight = 127;
  1837.  
  1838. /// ProcessWarningOptions - Initialize the diagnostic client and process the
  1839. /// warning options specified on the command line.
  1840. void ProcessWarningOptions(DiagnosticsEngine &Diags,
  1841.                            const DiagnosticOptions &Opts,
  1842.                            bool ReportDiags = true);
  1843.  
  1844. } // namespace clang
  1845.  
  1846. #endif // LLVM_CLANG_BASIC_DIAGNOSTIC_H
  1847.