1//===--- DiagnosticIDs.cpp - Diagnostic IDs Handling ----------------------===//
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//  This file implements the Diagnostic IDs-related interfaces.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Basic/DiagnosticIDs.h"
14#include "clang/Basic/AllDiagnostics.h"
15#include "clang/Basic/DiagnosticCategories.h"
16#include "clang/Basic/SourceManager.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Support/ErrorHandling.h"
20#include <map>
21#include <optional>
22using namespace clang;
23
24//===----------------------------------------------------------------------===//
25// Builtin Diagnostic information
26//===----------------------------------------------------------------------===//
27
28namespace {
29
30struct StaticDiagInfoRec;
31
32// Store the descriptions in a separate table to avoid pointers that need to
33// be relocated, and also decrease the amount of data needed on 64-bit
34// platforms. See "How To Write Shared Libraries" by Ulrich Drepper.
35struct StaticDiagInfoDescriptionStringTable {
36#define DIAG(ENUM, CLASS, DEFAULT_SEVERITY, DESC, GROUP, SFINAE, NOWERROR,     \
37             SHOWINSYSHEADER, SHOWINSYSMACRO, DEFERRABLE, CATEGORY)            \
38  char ENUM##_desc[sizeof(DESC)];
39  // clang-format off
40#include "clang/Basic/DiagnosticCommonKinds.inc"
41#include "clang/Basic/DiagnosticDriverKinds.inc"
42#include "clang/Basic/DiagnosticFrontendKinds.inc"
43#include "clang/Basic/DiagnosticSerializationKinds.inc"
44#include "clang/Basic/DiagnosticLexKinds.inc"
45#include "clang/Basic/DiagnosticParseKinds.inc"
46#include "clang/Basic/DiagnosticASTKinds.inc"
47#include "clang/Basic/DiagnosticCommentKinds.inc"
48#include "clang/Basic/DiagnosticCrossTUKinds.inc"
49#include "clang/Basic/DiagnosticSemaKinds.inc"
50#include "clang/Basic/DiagnosticAnalysisKinds.inc"
51#include "clang/Basic/DiagnosticRefactoringKinds.inc"
52  // clang-format on
53#undef DIAG
54};
55
56const StaticDiagInfoDescriptionStringTable StaticDiagInfoDescriptions = {
57#define DIAG(ENUM, CLASS, DEFAULT_SEVERITY, DESC, GROUP, SFINAE, NOWERROR,     \
58             SHOWINSYSHEADER, SHOWINSYSMACRO, DEFERRABLE, CATEGORY)            \
59  DESC,
60// clang-format off
61#include "clang/Basic/DiagnosticCommonKinds.inc"
62#include "clang/Basic/DiagnosticDriverKinds.inc"
63#include "clang/Basic/DiagnosticFrontendKinds.inc"
64#include "clang/Basic/DiagnosticSerializationKinds.inc"
65#include "clang/Basic/DiagnosticLexKinds.inc"
66#include "clang/Basic/DiagnosticParseKinds.inc"
67#include "clang/Basic/DiagnosticASTKinds.inc"
68#include "clang/Basic/DiagnosticCommentKinds.inc"
69#include "clang/Basic/DiagnosticCrossTUKinds.inc"
70#include "clang/Basic/DiagnosticSemaKinds.inc"
71#include "clang/Basic/DiagnosticAnalysisKinds.inc"
72#include "clang/Basic/DiagnosticRefactoringKinds.inc"
73  // clang-format on
74#undef DIAG
75};
76
77extern const StaticDiagInfoRec StaticDiagInfo[];
78
79// Stored separately from StaticDiagInfoRec to pack better.  Otherwise,
80// StaticDiagInfoRec would have extra padding on 64-bit platforms.
81const uint32_t StaticDiagInfoDescriptionOffsets[] = {
82#define DIAG(ENUM, CLASS, DEFAULT_SEVERITY, DESC, GROUP, SFINAE, NOWERROR,     \
83             SHOWINSYSHEADER, SHOWINSYSMACRO, DEFERRABLE, CATEGORY)            \
84  offsetof(StaticDiagInfoDescriptionStringTable, ENUM##_desc),
85// clang-format off
86#include "clang/Basic/DiagnosticCommonKinds.inc"
87#include "clang/Basic/DiagnosticDriverKinds.inc"
88#include "clang/Basic/DiagnosticFrontendKinds.inc"
89#include "clang/Basic/DiagnosticSerializationKinds.inc"
90#include "clang/Basic/DiagnosticLexKinds.inc"
91#include "clang/Basic/DiagnosticParseKinds.inc"
92#include "clang/Basic/DiagnosticASTKinds.inc"
93#include "clang/Basic/DiagnosticCommentKinds.inc"
94#include "clang/Basic/DiagnosticCrossTUKinds.inc"
95#include "clang/Basic/DiagnosticSemaKinds.inc"
96#include "clang/Basic/DiagnosticAnalysisKinds.inc"
97#include "clang/Basic/DiagnosticRefactoringKinds.inc"
98  // clang-format on
99#undef DIAG
100};
101
102// Diagnostic classes.
103enum {
104  CLASS_NOTE       = 0x01,
105  CLASS_REMARK     = 0x02,
106  CLASS_WARNING    = 0x03,
107  CLASS_EXTENSION  = 0x04,
108  CLASS_ERROR      = 0x05
109};
110
111struct StaticDiagInfoRec {
112  uint16_t DiagID;
113  uint8_t DefaultSeverity : 3;
114  uint8_t Class : 3;
115  uint8_t SFINAE : 2;
116  uint8_t Category : 6;
117  uint8_t WarnNoWerror : 1;
118  uint8_t WarnShowInSystemHeader : 1;
119  uint8_t WarnShowInSystemMacro : 1;
120
121  uint16_t OptionGroupIndex : 15;
122  uint16_t Deferrable : 1;
123
124  uint16_t DescriptionLen;
125
126  unsigned getOptionGroupIndex() const {
127    return OptionGroupIndex;
128  }
129
130  StringRef getDescription() const {
131    size_t MyIndex = this - &StaticDiagInfo[0];
132    uint32_t StringOffset = StaticDiagInfoDescriptionOffsets[MyIndex];
133    const char* Table = reinterpret_cast<const char*>(&StaticDiagInfoDescriptions);
134    return StringRef(&Table[StringOffset], DescriptionLen);
135  }
136
137  diag::Flavor getFlavor() const {
138    return Class == CLASS_REMARK ? diag::Flavor::Remark
139                                 : diag::Flavor::WarningOrError;
140  }
141
142  bool operator<(const StaticDiagInfoRec &RHS) const {
143    return DiagID < RHS.DiagID;
144  }
145};
146
147#define STRINGIFY_NAME(NAME) #NAME
148#define VALIDATE_DIAG_SIZE(NAME)                                               \
149  static_assert(                                                               \
150      static_cast<unsigned>(diag::NUM_BUILTIN_##NAME##_DIAGNOSTICS) <          \
151          static_cast<unsigned>(diag::DIAG_START_##NAME) +                     \
152              static_cast<unsigned>(diag::DIAG_SIZE_##NAME),                   \
153      STRINGIFY_NAME(                                                          \
154          DIAG_SIZE_##NAME) " is insufficient to contain all "                 \
155                            "diagnostics, it may need to be made larger in "   \
156                            "DiagnosticIDs.h.");
157VALIDATE_DIAG_SIZE(COMMON)
158VALIDATE_DIAG_SIZE(DRIVER)
159VALIDATE_DIAG_SIZE(FRONTEND)
160VALIDATE_DIAG_SIZE(SERIALIZATION)
161VALIDATE_DIAG_SIZE(LEX)
162VALIDATE_DIAG_SIZE(PARSE)
163VALIDATE_DIAG_SIZE(AST)
164VALIDATE_DIAG_SIZE(COMMENT)
165VALIDATE_DIAG_SIZE(CROSSTU)
166VALIDATE_DIAG_SIZE(SEMA)
167VALIDATE_DIAG_SIZE(ANALYSIS)
168VALIDATE_DIAG_SIZE(REFACTORING)
169#undef VALIDATE_DIAG_SIZE
170#undef STRINGIFY_NAME
171
172const StaticDiagInfoRec StaticDiagInfo[] = {
173// clang-format off
174#define DIAG(ENUM, CLASS, DEFAULT_SEVERITY, DESC, GROUP, SFINAE, NOWERROR,     \
175             SHOWINSYSHEADER, SHOWINSYSMACRO, DEFERRABLE, CATEGORY)            \
176  {                                                                            \
177      diag::ENUM,                                                              \
178      DEFAULT_SEVERITY,                                                        \
179      CLASS,                                                                   \
180      DiagnosticIDs::SFINAE,                                                   \
181      CATEGORY,                                                                \
182      NOWERROR,                                                                \
183      SHOWINSYSHEADER,                                                         \
184      SHOWINSYSMACRO,                                                          \
185      GROUP,                                                                   \
186	    DEFERRABLE,                                                              \
187      STR_SIZE(DESC, uint16_t)},
188#include "clang/Basic/DiagnosticCommonKinds.inc"
189#include "clang/Basic/DiagnosticDriverKinds.inc"
190#include "clang/Basic/DiagnosticFrontendKinds.inc"
191#include "clang/Basic/DiagnosticSerializationKinds.inc"
192#include "clang/Basic/DiagnosticLexKinds.inc"
193#include "clang/Basic/DiagnosticParseKinds.inc"
194#include "clang/Basic/DiagnosticASTKinds.inc"
195#include "clang/Basic/DiagnosticCommentKinds.inc"
196#include "clang/Basic/DiagnosticCrossTUKinds.inc"
197#include "clang/Basic/DiagnosticSemaKinds.inc"
198#include "clang/Basic/DiagnosticAnalysisKinds.inc"
199#include "clang/Basic/DiagnosticRefactoringKinds.inc"
200// clang-format on
201#undef DIAG
202};
203
204} // namespace
205
206static const unsigned StaticDiagInfoSize = std::size(StaticDiagInfo);
207
208/// GetDiagInfo - Return the StaticDiagInfoRec entry for the specified DiagID,
209/// or null if the ID is invalid.
210static const StaticDiagInfoRec *GetDiagInfo(unsigned DiagID) {
211  // Out of bounds diag. Can't be in the table.
212  using namespace diag;
213  if (DiagID >= DIAG_UPPER_LIMIT || DiagID <= DIAG_START_COMMON)
214    return nullptr;
215
216  // Compute the index of the requested diagnostic in the static table.
217  // 1. Add the number of diagnostics in each category preceding the
218  //    diagnostic and of the category the diagnostic is in. This gives us
219  //    the offset of the category in the table.
220  // 2. Subtract the number of IDs in each category from our ID. This gives us
221  //    the offset of the diagnostic in the category.
222  // This is cheaper than a binary search on the table as it doesn't touch
223  // memory at all.
224  unsigned Offset = 0;
225  unsigned ID = DiagID - DIAG_START_COMMON - 1;
226#define CATEGORY(NAME, PREV) \
227  if (DiagID > DIAG_START_##NAME) { \
228    Offset += NUM_BUILTIN_##PREV##_DIAGNOSTICS - DIAG_START_##PREV - 1; \
229    ID -= DIAG_START_##NAME - DIAG_START_##PREV; \
230  }
231CATEGORY(DRIVER, COMMON)
232CATEGORY(FRONTEND, DRIVER)
233CATEGORY(SERIALIZATION, FRONTEND)
234CATEGORY(LEX, SERIALIZATION)
235CATEGORY(PARSE, LEX)
236CATEGORY(AST, PARSE)
237CATEGORY(COMMENT, AST)
238CATEGORY(CROSSTU, COMMENT)
239CATEGORY(SEMA, CROSSTU)
240CATEGORY(ANALYSIS, SEMA)
241CATEGORY(REFACTORING, ANALYSIS)
242#undef CATEGORY
243
244  // Avoid out of bounds reads.
245  if (ID + Offset >= StaticDiagInfoSize)
246    return nullptr;
247
248  assert(ID < StaticDiagInfoSize && Offset < StaticDiagInfoSize);
249
250  const StaticDiagInfoRec *Found = &StaticDiagInfo[ID + Offset];
251  // If the diag id doesn't match we found a different diag, abort. This can
252  // happen when this function is called with an ID that points into a hole in
253  // the diagID space.
254  if (Found->DiagID != DiagID)
255    return nullptr;
256  return Found;
257}
258
259DiagnosticMapping DiagnosticIDs::getDefaultMapping(unsigned DiagID) {
260  DiagnosticMapping Info = DiagnosticMapping::Make(
261      diag::Severity::Fatal, /*IsUser=*/false, /*IsPragma=*/false);
262
263  if (const StaticDiagInfoRec *StaticInfo = GetDiagInfo(DiagID)) {
264    Info.setSeverity((diag::Severity)StaticInfo->DefaultSeverity);
265
266    if (StaticInfo->WarnNoWerror) {
267      assert(Info.getSeverity() == diag::Severity::Warning &&
268             "Unexpected mapping with no-Werror bit!");
269      Info.setNoWarningAsError(true);
270    }
271  }
272
273  return Info;
274}
275
276/// getCategoryNumberForDiag - Return the category number that a specified
277/// DiagID belongs to, or 0 if no category.
278unsigned DiagnosticIDs::getCategoryNumberForDiag(unsigned DiagID) {
279  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
280    return Info->Category;
281  return 0;
282}
283
284namespace {
285  // The diagnostic category names.
286  struct StaticDiagCategoryRec {
287    const char *NameStr;
288    uint8_t NameLen;
289
290    StringRef getName() const {
291      return StringRef(NameStr, NameLen);
292    }
293  };
294}
295
296static const StaticDiagCategoryRec CategoryNameTable[] = {
297#define GET_CATEGORY_TABLE
298#define CATEGORY(X, ENUM) { X, STR_SIZE(X, uint8_t) },
299#include "clang/Basic/DiagnosticGroups.inc"
300#undef GET_CATEGORY_TABLE
301  { nullptr, 0 }
302};
303
304/// getNumberOfCategories - Return the number of categories
305unsigned DiagnosticIDs::getNumberOfCategories() {
306  return std::size(CategoryNameTable) - 1;
307}
308
309/// getCategoryNameFromID - Given a category ID, return the name of the
310/// category, an empty string if CategoryID is zero, or null if CategoryID is
311/// invalid.
312StringRef DiagnosticIDs::getCategoryNameFromID(unsigned CategoryID) {
313  if (CategoryID >= getNumberOfCategories())
314   return StringRef();
315  return CategoryNameTable[CategoryID].getName();
316}
317
318
319
320DiagnosticIDs::SFINAEResponse
321DiagnosticIDs::getDiagnosticSFINAEResponse(unsigned DiagID) {
322  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
323    return static_cast<DiagnosticIDs::SFINAEResponse>(Info->SFINAE);
324  return SFINAE_Report;
325}
326
327bool DiagnosticIDs::isDeferrable(unsigned DiagID) {
328  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
329    return Info->Deferrable;
330  return false;
331}
332
333/// getBuiltinDiagClass - Return the class field of the diagnostic.
334///
335static unsigned getBuiltinDiagClass(unsigned DiagID) {
336  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
337    return Info->Class;
338  return ~0U;
339}
340
341//===----------------------------------------------------------------------===//
342// Custom Diagnostic information
343//===----------------------------------------------------------------------===//
344
345namespace clang {
346  namespace diag {
347    class CustomDiagInfo {
348      typedef std::pair<DiagnosticIDs::Level, std::string> DiagDesc;
349      std::vector<DiagDesc> DiagInfo;
350      std::map<DiagDesc, unsigned> DiagIDs;
351    public:
352
353      /// getDescription - Return the description of the specified custom
354      /// diagnostic.
355      StringRef getDescription(unsigned DiagID) const {
356        assert(DiagID - DIAG_UPPER_LIMIT < DiagInfo.size() &&
357               "Invalid diagnostic ID");
358        return DiagInfo[DiagID-DIAG_UPPER_LIMIT].second;
359      }
360
361      /// getLevel - Return the level of the specified custom diagnostic.
362      DiagnosticIDs::Level getLevel(unsigned DiagID) const {
363        assert(DiagID - DIAG_UPPER_LIMIT < DiagInfo.size() &&
364               "Invalid diagnostic ID");
365        return DiagInfo[DiagID-DIAG_UPPER_LIMIT].first;
366      }
367
368      unsigned getOrCreateDiagID(DiagnosticIDs::Level L, StringRef Message,
369                                 DiagnosticIDs &Diags) {
370        DiagDesc D(L, std::string(Message));
371        // Check to see if it already exists.
372        std::map<DiagDesc, unsigned>::iterator I = DiagIDs.lower_bound(D);
373        if (I != DiagIDs.end() && I->first == D)
374          return I->second;
375
376        // If not, assign a new ID.
377        unsigned ID = DiagInfo.size()+DIAG_UPPER_LIMIT;
378        DiagIDs.insert(std::make_pair(D, ID));
379        DiagInfo.push_back(D);
380        return ID;
381      }
382    };
383
384  } // end diag namespace
385} // end clang namespace
386
387
388//===----------------------------------------------------------------------===//
389// Common Diagnostic implementation
390//===----------------------------------------------------------------------===//
391
392DiagnosticIDs::DiagnosticIDs() {}
393
394DiagnosticIDs::~DiagnosticIDs() {}
395
396/// getCustomDiagID - Return an ID for a diagnostic with the specified message
397/// and level.  If this is the first request for this diagnostic, it is
398/// registered and created, otherwise the existing ID is returned.
399///
400/// \param FormatString A fixed diagnostic format string that will be hashed and
401/// mapped to a unique DiagID.
402unsigned DiagnosticIDs::getCustomDiagID(Level L, StringRef FormatString) {
403  if (!CustomDiagInfo)
404    CustomDiagInfo.reset(new diag::CustomDiagInfo());
405  return CustomDiagInfo->getOrCreateDiagID(L, FormatString, *this);
406}
407
408
409/// isBuiltinWarningOrExtension - Return true if the unmapped diagnostic
410/// level of the specified diagnostic ID is a Warning or Extension.
411/// This only works on builtin diagnostics, not custom ones, and is not legal to
412/// call on NOTEs.
413bool DiagnosticIDs::isBuiltinWarningOrExtension(unsigned DiagID) {
414  return DiagID < diag::DIAG_UPPER_LIMIT &&
415         getBuiltinDiagClass(DiagID) != CLASS_ERROR;
416}
417
418/// Determine whether the given built-in diagnostic ID is a
419/// Note.
420bool DiagnosticIDs::isBuiltinNote(unsigned DiagID) {
421  return DiagID < diag::DIAG_UPPER_LIMIT &&
422    getBuiltinDiagClass(DiagID) == CLASS_NOTE;
423}
424
425/// isBuiltinExtensionDiag - Determine whether the given built-in diagnostic
426/// ID is for an extension of some sort.  This also returns EnabledByDefault,
427/// which is set to indicate whether the diagnostic is ignored by default (in
428/// which case -pedantic enables it) or treated as a warning/error by default.
429///
430bool DiagnosticIDs::isBuiltinExtensionDiag(unsigned DiagID,
431                                        bool &EnabledByDefault) {
432  if (DiagID >= diag::DIAG_UPPER_LIMIT ||
433      getBuiltinDiagClass(DiagID) != CLASS_EXTENSION)
434    return false;
435
436  EnabledByDefault =
437      getDefaultMapping(DiagID).getSeverity() != diag::Severity::Ignored;
438  return true;
439}
440
441bool DiagnosticIDs::isDefaultMappingAsError(unsigned DiagID) {
442  if (DiagID >= diag::DIAG_UPPER_LIMIT)
443    return false;
444
445  return getDefaultMapping(DiagID).getSeverity() >= diag::Severity::Error;
446}
447
448/// getDescription - Given a diagnostic ID, return a description of the
449/// issue.
450StringRef DiagnosticIDs::getDescription(unsigned DiagID) const {
451  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
452    return Info->getDescription();
453  assert(CustomDiagInfo && "Invalid CustomDiagInfo");
454  return CustomDiagInfo->getDescription(DiagID);
455}
456
457static DiagnosticIDs::Level toLevel(diag::Severity SV) {
458  switch (SV) {
459  case diag::Severity::Ignored:
460    return DiagnosticIDs::Ignored;
461  case diag::Severity::Remark:
462    return DiagnosticIDs::Remark;
463  case diag::Severity::Warning:
464    return DiagnosticIDs::Warning;
465  case diag::Severity::Error:
466    return DiagnosticIDs::Error;
467  case diag::Severity::Fatal:
468    return DiagnosticIDs::Fatal;
469  }
470  llvm_unreachable("unexpected severity");
471}
472
473/// getDiagnosticLevel - Based on the way the client configured the
474/// DiagnosticsEngine object, classify the specified diagnostic ID into a Level,
475/// by consumable the DiagnosticClient.
476DiagnosticIDs::Level
477DiagnosticIDs::getDiagnosticLevel(unsigned DiagID, SourceLocation Loc,
478                                  const DiagnosticsEngine &Diag) const {
479  // Handle custom diagnostics, which cannot be mapped.
480  if (DiagID >= diag::DIAG_UPPER_LIMIT) {
481    assert(CustomDiagInfo && "Invalid CustomDiagInfo");
482    return CustomDiagInfo->getLevel(DiagID);
483  }
484
485  unsigned DiagClass = getBuiltinDiagClass(DiagID);
486  if (DiagClass == CLASS_NOTE) return DiagnosticIDs::Note;
487  return toLevel(getDiagnosticSeverity(DiagID, Loc, Diag));
488}
489
490/// Based on the way the client configured the Diagnostic
491/// object, classify the specified diagnostic ID into a Level, consumable by
492/// the DiagnosticClient.
493///
494/// \param Loc The source location we are interested in finding out the
495/// diagnostic state. Can be null in order to query the latest state.
496diag::Severity
497DiagnosticIDs::getDiagnosticSeverity(unsigned DiagID, SourceLocation Loc,
498                                     const DiagnosticsEngine &Diag) const {
499  assert(getBuiltinDiagClass(DiagID) != CLASS_NOTE);
500
501  // Specific non-error diagnostics may be mapped to various levels from ignored
502  // to error.  Errors can only be mapped to fatal.
503  diag::Severity Result = diag::Severity::Fatal;
504
505  // Get the mapping information, or compute it lazily.
506  DiagnosticsEngine::DiagState *State = Diag.GetDiagStateForLoc(Loc);
507  DiagnosticMapping &Mapping = State->getOrAddMapping((diag::kind)DiagID);
508
509  // TODO: Can a null severity really get here?
510  if (Mapping.getSeverity() != diag::Severity())
511    Result = Mapping.getSeverity();
512
513  // Upgrade ignored diagnostics if -Weverything is enabled.
514  if (State->EnableAllWarnings && Result == diag::Severity::Ignored &&
515      !Mapping.isUser() && getBuiltinDiagClass(DiagID) != CLASS_REMARK)
516    Result = diag::Severity::Warning;
517
518  // Ignore -pedantic diagnostics inside __extension__ blocks.
519  // (The diagnostics controlled by -pedantic are the extension diagnostics
520  // that are not enabled by default.)
521  bool EnabledByDefault = false;
522  bool IsExtensionDiag = isBuiltinExtensionDiag(DiagID, EnabledByDefault);
523  if (Diag.AllExtensionsSilenced && IsExtensionDiag && !EnabledByDefault)
524    return diag::Severity::Ignored;
525
526  // For extension diagnostics that haven't been explicitly mapped, check if we
527  // should upgrade the diagnostic.
528  if (IsExtensionDiag && !Mapping.isUser())
529    Result = std::max(Result, State->ExtBehavior);
530
531  // At this point, ignored errors can no longer be upgraded.
532  if (Result == diag::Severity::Ignored)
533    return Result;
534
535  // Honor -w: this disables all messages which are not Error/Fatal by
536  // default (disregarding attempts to upgrade severity from Warning to Error),
537  // as well as disabling all messages which are currently mapped to Warning
538  // (whether by default or downgraded from Error via e.g. -Wno-error or #pragma
539  // diagnostic.)
540  if (State->IgnoreAllWarnings) {
541    if (Result == diag::Severity::Warning ||
542        (Result >= diag::Severity::Error &&
543         !isDefaultMappingAsError((diag::kind)DiagID)))
544      return diag::Severity::Ignored;
545  }
546
547  // If -Werror is enabled, map warnings to errors unless explicitly disabled.
548  if (Result == diag::Severity::Warning) {
549    if (State->WarningsAsErrors && !Mapping.hasNoWarningAsError())
550      Result = diag::Severity::Error;
551  }
552
553  // If -Wfatal-errors is enabled, map errors to fatal unless explicitly
554  // disabled.
555  if (Result == diag::Severity::Error) {
556    if (State->ErrorsAsFatal && !Mapping.hasNoErrorAsFatal())
557      Result = diag::Severity::Fatal;
558  }
559
560  // If explicitly requested, map fatal errors to errors.
561  if (Result == diag::Severity::Fatal &&
562      Diag.CurDiagID != diag::fatal_too_many_errors && Diag.FatalsAsError)
563    Result = diag::Severity::Error;
564
565  // Custom diagnostics always are emitted in system headers.
566  bool ShowInSystemHeader =
567      !GetDiagInfo(DiagID) || GetDiagInfo(DiagID)->WarnShowInSystemHeader;
568
569  // If we are in a system header, we ignore it. We look at the diagnostic class
570  // because we also want to ignore extensions and warnings in -Werror and
571  // -pedantic-errors modes, which *map* warnings/extensions to errors.
572  if (State->SuppressSystemWarnings && !ShowInSystemHeader && Loc.isValid() &&
573      Diag.getSourceManager().isInSystemHeader(
574          Diag.getSourceManager().getExpansionLoc(Loc)))
575    return diag::Severity::Ignored;
576
577  // We also ignore warnings due to system macros
578  bool ShowInSystemMacro =
579      !GetDiagInfo(DiagID) || GetDiagInfo(DiagID)->WarnShowInSystemMacro;
580  if (State->SuppressSystemWarnings && !ShowInSystemMacro && Loc.isValid() &&
581      Diag.getSourceManager().isInSystemMacro(Loc))
582    return diag::Severity::Ignored;
583
584  return Result;
585}
586
587#define GET_DIAG_ARRAYS
588#include "clang/Basic/DiagnosticGroups.inc"
589#undef GET_DIAG_ARRAYS
590
591namespace {
592  struct WarningOption {
593    uint16_t NameOffset;
594    uint16_t Members;
595    uint16_t SubGroups;
596    StringRef Documentation;
597
598    // String is stored with a pascal-style length byte.
599    StringRef getName() const {
600      return StringRef(DiagGroupNames + NameOffset + 1,
601                       DiagGroupNames[NameOffset]);
602    }
603  };
604}
605
606// Second the table of options, sorted by name for fast binary lookup.
607static const WarningOption OptionTable[] = {
608#define DIAG_ENTRY(GroupName, FlagNameOffset, Members, SubGroups, Docs)        \
609  {FlagNameOffset, Members, SubGroups, Docs},
610#include "clang/Basic/DiagnosticGroups.inc"
611#undef DIAG_ENTRY
612};
613
614/// Given a diagnostic group ID, return its documentation.
615StringRef DiagnosticIDs::getWarningOptionDocumentation(diag::Group Group) {
616  return OptionTable[static_cast<int>(Group)].Documentation;
617}
618
619StringRef DiagnosticIDs::getWarningOptionForGroup(diag::Group Group) {
620  return OptionTable[static_cast<int>(Group)].getName();
621}
622
623std::optional<diag::Group>
624DiagnosticIDs::getGroupForWarningOption(StringRef Name) {
625  const auto *Found = llvm::partition_point(
626      OptionTable, [=](const WarningOption &O) { return O.getName() < Name; });
627  if (Found == std::end(OptionTable) || Found->getName() != Name)
628    return std::nullopt;
629  return static_cast<diag::Group>(Found - OptionTable);
630}
631
632std::optional<diag::Group> DiagnosticIDs::getGroupForDiag(unsigned DiagID) {
633  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
634    return static_cast<diag::Group>(Info->getOptionGroupIndex());
635  return std::nullopt;
636}
637
638/// getWarningOptionForDiag - Return the lowest-level warning option that
639/// enables the specified diagnostic.  If there is no -Wfoo flag that controls
640/// the diagnostic, this returns null.
641StringRef DiagnosticIDs::getWarningOptionForDiag(unsigned DiagID) {
642  if (auto G = getGroupForDiag(DiagID))
643    return getWarningOptionForGroup(*G);
644  return StringRef();
645}
646
647std::vector<std::string> DiagnosticIDs::getDiagnosticFlags() {
648  std::vector<std::string> Res{"-W", "-Wno-"};
649  for (size_t I = 1; DiagGroupNames[I] != '\0';) {
650    std::string Diag(DiagGroupNames + I + 1, DiagGroupNames[I]);
651    I += DiagGroupNames[I] + 1;
652    Res.push_back("-W" + Diag);
653    Res.push_back("-Wno-" + Diag);
654  }
655
656  return Res;
657}
658
659/// Return \c true if any diagnostics were found in this group, even if they
660/// were filtered out due to having the wrong flavor.
661static bool getDiagnosticsInGroup(diag::Flavor Flavor,
662                                  const WarningOption *Group,
663                                  SmallVectorImpl<diag::kind> &Diags) {
664  // An empty group is considered to be a warning group: we have empty groups
665  // for GCC compatibility, and GCC does not have remarks.
666  if (!Group->Members && !Group->SubGroups)
667    return Flavor == diag::Flavor::Remark;
668
669  bool NotFound = true;
670
671  // Add the members of the option diagnostic set.
672  const int16_t *Member = DiagArrays + Group->Members;
673  for (; *Member != -1; ++Member) {
674    if (GetDiagInfo(*Member)->getFlavor() == Flavor) {
675      NotFound = false;
676      Diags.push_back(*Member);
677    }
678  }
679
680  // Add the members of the subgroups.
681  const int16_t *SubGroups = DiagSubGroups + Group->SubGroups;
682  for (; *SubGroups != (int16_t)-1; ++SubGroups)
683    NotFound &= getDiagnosticsInGroup(Flavor, &OptionTable[(short)*SubGroups],
684                                      Diags);
685
686  return NotFound;
687}
688
689bool
690DiagnosticIDs::getDiagnosticsInGroup(diag::Flavor Flavor, StringRef Group,
691                                     SmallVectorImpl<diag::kind> &Diags) const {
692  if (std::optional<diag::Group> G = getGroupForWarningOption(Group))
693    return ::getDiagnosticsInGroup(
694        Flavor, &OptionTable[static_cast<unsigned>(*G)], Diags);
695  return true;
696}
697
698void DiagnosticIDs::getAllDiagnostics(diag::Flavor Flavor,
699                                      std::vector<diag::kind> &Diags) {
700  for (unsigned i = 0; i != StaticDiagInfoSize; ++i)
701    if (StaticDiagInfo[i].getFlavor() == Flavor)
702      Diags.push_back(StaticDiagInfo[i].DiagID);
703}
704
705StringRef DiagnosticIDs::getNearestOption(diag::Flavor Flavor,
706                                          StringRef Group) {
707  StringRef Best;
708  unsigned BestDistance = Group.size() + 1; // Maximum threshold.
709  for (const WarningOption &O : OptionTable) {
710    // Don't suggest ignored warning flags.
711    if (!O.Members && !O.SubGroups)
712      continue;
713
714    unsigned Distance = O.getName().edit_distance(Group, true, BestDistance);
715    if (Distance > BestDistance)
716      continue;
717
718    // Don't suggest groups that are not of this kind.
719    llvm::SmallVector<diag::kind, 8> Diags;
720    if (::getDiagnosticsInGroup(Flavor, &O, Diags) || Diags.empty())
721      continue;
722
723    if (Distance == BestDistance) {
724      // Two matches with the same distance, don't prefer one over the other.
725      Best = "";
726    } else if (Distance < BestDistance) {
727      // This is a better match.
728      Best = O.getName();
729      BestDistance = Distance;
730    }
731  }
732
733  return Best;
734}
735
736/// ProcessDiag - This is the method used to report a diagnostic that is
737/// finally fully formed.
738bool DiagnosticIDs::ProcessDiag(DiagnosticsEngine &Diag) const {
739  Diagnostic Info(&Diag);
740
741  assert(Diag.getClient() && "DiagnosticClient not set!");
742
743  // Figure out the diagnostic level of this message.
744  unsigned DiagID = Info.getID();
745  DiagnosticIDs::Level DiagLevel
746    = getDiagnosticLevel(DiagID, Info.getLocation(), Diag);
747
748  // Update counts for DiagnosticErrorTrap even if a fatal error occurred
749  // or diagnostics are suppressed.
750  if (DiagLevel >= DiagnosticIDs::Error) {
751    ++Diag.TrapNumErrorsOccurred;
752    if (isUnrecoverable(DiagID))
753      ++Diag.TrapNumUnrecoverableErrorsOccurred;
754  }
755
756  if (Diag.SuppressAllDiagnostics)
757    return false;
758
759  if (DiagLevel != DiagnosticIDs::Note) {
760    // Record that a fatal error occurred only when we see a second
761    // non-note diagnostic. This allows notes to be attached to the
762    // fatal error, but suppresses any diagnostics that follow those
763    // notes.
764    if (Diag.LastDiagLevel == DiagnosticIDs::Fatal)
765      Diag.FatalErrorOccurred = true;
766
767    Diag.LastDiagLevel = DiagLevel;
768  }
769
770  // If a fatal error has already been emitted, silence all subsequent
771  // diagnostics.
772  if (Diag.FatalErrorOccurred) {
773    if (DiagLevel >= DiagnosticIDs::Error &&
774        Diag.Client->IncludeInDiagnosticCounts()) {
775      ++Diag.NumErrors;
776    }
777
778    return false;
779  }
780
781  // If the client doesn't care about this message, don't issue it.  If this is
782  // a note and the last real diagnostic was ignored, ignore it too.
783  if (DiagLevel == DiagnosticIDs::Ignored ||
784      (DiagLevel == DiagnosticIDs::Note &&
785       Diag.LastDiagLevel == DiagnosticIDs::Ignored))
786    return false;
787
788  if (DiagLevel >= DiagnosticIDs::Error) {
789    if (isUnrecoverable(DiagID))
790      Diag.UnrecoverableErrorOccurred = true;
791
792    // Warnings which have been upgraded to errors do not prevent compilation.
793    if (isDefaultMappingAsError(DiagID))
794      Diag.UncompilableErrorOccurred = true;
795
796    Diag.ErrorOccurred = true;
797    if (Diag.Client->IncludeInDiagnosticCounts()) {
798      ++Diag.NumErrors;
799    }
800
801    // If we've emitted a lot of errors, emit a fatal error instead of it to
802    // stop a flood of bogus errors.
803    if (Diag.ErrorLimit && Diag.NumErrors > Diag.ErrorLimit &&
804        DiagLevel == DiagnosticIDs::Error) {
805      Diag.SetDelayedDiagnostic(diag::fatal_too_many_errors);
806      return false;
807    }
808  }
809
810  // Make sure we set FatalErrorOccurred to ensure that the notes from the
811  // diagnostic that caused `fatal_too_many_errors` won't be emitted.
812  if (Diag.CurDiagID == diag::fatal_too_many_errors)
813    Diag.FatalErrorOccurred = true;
814  // Finally, report it.
815  EmitDiag(Diag, DiagLevel);
816  return true;
817}
818
819void DiagnosticIDs::EmitDiag(DiagnosticsEngine &Diag, Level DiagLevel) const {
820  Diagnostic Info(&Diag);
821  assert(DiagLevel != DiagnosticIDs::Ignored && "Cannot emit ignored diagnostics!");
822
823  Diag.Client->HandleDiagnostic((DiagnosticsEngine::Level)DiagLevel, Info);
824  if (Diag.Client->IncludeInDiagnosticCounts()) {
825    if (DiagLevel == DiagnosticIDs::Warning)
826      ++Diag.NumWarnings;
827  }
828
829  Diag.CurDiagID = ~0U;
830}
831
832bool DiagnosticIDs::isUnrecoverable(unsigned DiagID) const {
833  if (DiagID >= diag::DIAG_UPPER_LIMIT) {
834    assert(CustomDiagInfo && "Invalid CustomDiagInfo");
835    // Custom diagnostics.
836    return CustomDiagInfo->getLevel(DiagID) >= DiagnosticIDs::Error;
837  }
838
839  // Only errors may be unrecoverable.
840  if (getBuiltinDiagClass(DiagID) < CLASS_ERROR)
841    return false;
842
843  if (DiagID == diag::err_unavailable ||
844      DiagID == diag::err_unavailable_message)
845    return false;
846
847  // Currently we consider all ARC errors as recoverable.
848  if (isARCDiagnostic(DiagID))
849    return false;
850
851  return true;
852}
853
854bool DiagnosticIDs::isARCDiagnostic(unsigned DiagID) {
855  unsigned cat = getCategoryNumberForDiag(DiagID);
856  return DiagnosticIDs::getCategoryNameFromID(cat).starts_with("ARC ");
857}
858