xref: /llvm-project/clang/lib/Frontend/SerializedDiagnosticPrinter.cpp (revision 0865ecc5150b9a55ba1f9e30b6d463a66ac362a6)
1 //===--- SerializedDiagnosticPrinter.cpp - Serializer for diagnostics -----===//
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 #include "clang/Frontend/SerializedDiagnosticPrinter.h"
10 #include "clang/Basic/Diagnostic.h"
11 #include "clang/Basic/DiagnosticOptions.h"
12 #include "clang/Basic/SourceManager.h"
13 #include "clang/Frontend/DiagnosticRenderer.h"
14 #include "clang/Frontend/FrontendDiagnostic.h"
15 #include "clang/Frontend/SerializedDiagnosticReader.h"
16 #include "clang/Frontend/SerializedDiagnostics.h"
17 #include "clang/Frontend/TextDiagnosticPrinter.h"
18 #include "clang/Lex/Lexer.h"
19 #include "llvm/ADT/DenseSet.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/StringRef.h"
23 #include "llvm/Bitstream/BitCodes.h"
24 #include "llvm/Bitstream/BitstreamReader.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include <utility>
28 
29 using namespace clang;
30 using namespace clang::serialized_diags;
31 
32 namespace {
33 
34 class AbbreviationMap {
35   llvm::DenseMap<unsigned, unsigned> Abbrevs;
36 public:
37   AbbreviationMap() {}
38 
39   void set(unsigned recordID, unsigned abbrevID) {
40     assert(!Abbrevs.contains(recordID) && "Abbreviation already set.");
41     Abbrevs[recordID] = abbrevID;
42   }
43 
44   unsigned get(unsigned recordID) {
45     assert(Abbrevs.contains(recordID) && "Abbreviation not set.");
46     return Abbrevs[recordID];
47   }
48 };
49 
50 typedef SmallVector<uint64_t, 64> RecordData;
51 typedef SmallVectorImpl<uint64_t> RecordDataImpl;
52 typedef ArrayRef<uint64_t> RecordDataRef;
53 
54 class SDiagsWriter;
55 
56 class SDiagsRenderer : public DiagnosticNoteRenderer {
57   SDiagsWriter &Writer;
58 public:
59   SDiagsRenderer(SDiagsWriter &Writer, const LangOptions &LangOpts,
60                  DiagnosticOptions *DiagOpts)
61     : DiagnosticNoteRenderer(LangOpts, DiagOpts), Writer(Writer) {}
62 
63   ~SDiagsRenderer() override {}
64 
65 protected:
66   void emitDiagnosticMessage(FullSourceLoc Loc, PresumedLoc PLoc,
67                              DiagnosticsEngine::Level Level, StringRef Message,
68                              ArrayRef<CharSourceRange> Ranges,
69                              DiagOrStoredDiag D) override;
70 
71   void emitDiagnosticLoc(FullSourceLoc Loc, PresumedLoc PLoc,
72                          DiagnosticsEngine::Level Level,
73                          ArrayRef<CharSourceRange> Ranges) override {}
74 
75   void emitNote(FullSourceLoc Loc, StringRef Message) override;
76 
77   void emitCodeContext(FullSourceLoc Loc, DiagnosticsEngine::Level Level,
78                        SmallVectorImpl<CharSourceRange> &Ranges,
79                        ArrayRef<FixItHint> Hints) override;
80 
81   void beginDiagnostic(DiagOrStoredDiag D,
82                        DiagnosticsEngine::Level Level) override;
83   void endDiagnostic(DiagOrStoredDiag D,
84                      DiagnosticsEngine::Level Level) override;
85 };
86 
87 typedef llvm::DenseMap<unsigned, unsigned> AbbrevLookup;
88 
89 class SDiagsMerger : SerializedDiagnosticReader {
90   SDiagsWriter &Writer;
91   AbbrevLookup FileLookup;
92   AbbrevLookup CategoryLookup;
93   AbbrevLookup DiagFlagLookup;
94 
95 public:
96   SDiagsMerger(SDiagsWriter &Writer) : Writer(Writer) {}
97 
98   std::error_code mergeRecordsFromFile(const char *File) {
99     return readDiagnostics(File);
100   }
101 
102 protected:
103   std::error_code visitStartOfDiagnostic() override;
104   std::error_code visitEndOfDiagnostic() override;
105   std::error_code visitCategoryRecord(unsigned ID, StringRef Name) override;
106   std::error_code visitDiagFlagRecord(unsigned ID, StringRef Name) override;
107   std::error_code visitDiagnosticRecord(
108       unsigned Severity, const serialized_diags::Location &Location,
109       unsigned Category, unsigned Flag, StringRef Message) override;
110   std::error_code visitFilenameRecord(unsigned ID, unsigned Size,
111                                       unsigned Timestamp,
112                                       StringRef Name) override;
113   std::error_code visitFixitRecord(const serialized_diags::Location &Start,
114                                    const serialized_diags::Location &End,
115                                    StringRef CodeToInsert) override;
116   std::error_code
117   visitSourceRangeRecord(const serialized_diags::Location &Start,
118                          const serialized_diags::Location &End) override;
119 
120 private:
121   std::error_code adjustSourceLocFilename(RecordData &Record,
122                                           unsigned int offset);
123 
124   void adjustAbbrevID(RecordData &Record, AbbrevLookup &Lookup,
125                       unsigned NewAbbrev);
126 
127   void writeRecordWithAbbrev(unsigned ID, RecordData &Record);
128 
129   void writeRecordWithBlob(unsigned ID, RecordData &Record, StringRef Blob);
130 };
131 
132 class SDiagsWriter : public DiagnosticConsumer {
133   friend class SDiagsRenderer;
134   friend class SDiagsMerger;
135 
136   struct SharedState;
137 
138   explicit SDiagsWriter(std::shared_ptr<SharedState> State)
139       : LangOpts(nullptr), OriginalInstance(false), MergeChildRecords(false),
140         State(std::move(State)) {}
141 
142 public:
143   SDiagsWriter(StringRef File, DiagnosticOptions *Diags, bool MergeChildRecords)
144       : LangOpts(nullptr), OriginalInstance(true),
145         MergeChildRecords(MergeChildRecords),
146         State(std::make_shared<SharedState>(File, Diags)) {
147     if (MergeChildRecords)
148       RemoveOldDiagnostics();
149     EmitPreamble();
150   }
151 
152   ~SDiagsWriter() override {}
153 
154   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
155                         const Diagnostic &Info) override;
156 
157   void BeginSourceFile(const LangOptions &LO, const Preprocessor *PP) override {
158     LangOpts = &LO;
159   }
160 
161   void finish() override;
162 
163 private:
164   /// Build a DiagnosticsEngine to emit diagnostics about the diagnostics
165   DiagnosticsEngine *getMetaDiags();
166 
167   /// Remove old copies of the serialized diagnostics. This is necessary
168   /// so that we can detect when subprocesses write diagnostics that we should
169   /// merge into our own.
170   void RemoveOldDiagnostics();
171 
172   /// Emit the preamble for the serialized diagnostics.
173   void EmitPreamble();
174 
175   /// Emit the BLOCKINFO block.
176   void EmitBlockInfoBlock();
177 
178   /// Emit the META data block.
179   void EmitMetaBlock();
180 
181   /// Start a DIAG block.
182   void EnterDiagBlock();
183 
184   /// End a DIAG block.
185   void ExitDiagBlock();
186 
187   /// Emit a DIAG record.
188   void EmitDiagnosticMessage(FullSourceLoc Loc, PresumedLoc PLoc,
189                              DiagnosticsEngine::Level Level, StringRef Message,
190                              DiagOrStoredDiag D);
191 
192   /// Emit FIXIT and SOURCE_RANGE records for a diagnostic.
193   void EmitCodeContext(SmallVectorImpl<CharSourceRange> &Ranges,
194                        ArrayRef<FixItHint> Hints,
195                        const SourceManager &SM);
196 
197   /// Emit a record for a CharSourceRange.
198   void EmitCharSourceRange(CharSourceRange R, const SourceManager &SM);
199 
200   /// Emit the string information for the category.
201   unsigned getEmitCategory(unsigned category = 0);
202 
203   /// Emit the string information for diagnostic flags.
204   unsigned getEmitDiagnosticFlag(DiagnosticsEngine::Level DiagLevel,
205                                  const Diagnostic *Diag = nullptr);
206 
207   unsigned getEmitDiagnosticFlag(StringRef DiagName);
208 
209   /// Emit (lazily) the file string and retrieved the file identifier.
210   unsigned getEmitFile(const char *Filename);
211 
212   /// Add SourceLocation information the specified record.
213   void AddLocToRecord(FullSourceLoc Loc, PresumedLoc PLoc,
214                       RecordDataImpl &Record, unsigned TokSize = 0);
215 
216   /// Add SourceLocation information the specified record.
217   void AddLocToRecord(FullSourceLoc Loc, RecordDataImpl &Record,
218                       unsigned TokSize = 0) {
219     AddLocToRecord(Loc, Loc.hasManager() ? Loc.getPresumedLoc() : PresumedLoc(),
220                    Record, TokSize);
221   }
222 
223   /// Add CharSourceRange information the specified record.
224   void AddCharSourceRangeToRecord(CharSourceRange R, RecordDataImpl &Record,
225                                   const SourceManager &SM);
226 
227   /// Language options, which can differ from one clone of this client
228   /// to another.
229   const LangOptions *LangOpts;
230 
231   /// Whether this is the original instance (rather than one of its
232   /// clones), responsible for writing the file at the end.
233   bool OriginalInstance;
234 
235   /// Whether this instance should aggregate diagnostics that are
236   /// generated from child processes.
237   bool MergeChildRecords;
238 
239   /// Whether we've started finishing and tearing down this instance.
240   bool IsFinishing = false;
241 
242   /// State that is shared among the various clones of this diagnostic
243   /// consumer.
244   struct SharedState {
245     SharedState(StringRef File, DiagnosticOptions *Diags)
246         : DiagOpts(Diags), Stream(Buffer), OutputFile(File.str()),
247           EmittedAnyDiagBlocks(false) {}
248 
249     /// Diagnostic options.
250     IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts;
251 
252     /// The byte buffer for the serialized content.
253     SmallString<1024> Buffer;
254 
255     /// The BitStreamWriter for the serialized diagnostics.
256     llvm::BitstreamWriter Stream;
257 
258     /// The name of the diagnostics file.
259     std::string OutputFile;
260 
261     /// The set of constructed record abbreviations.
262     AbbreviationMap Abbrevs;
263 
264     /// A utility buffer for constructing record content.
265     RecordData Record;
266 
267     /// A text buffer for rendering diagnostic text.
268     SmallString<256> diagBuf;
269 
270     /// The collection of diagnostic categories used.
271     llvm::DenseSet<unsigned> Categories;
272 
273     /// The collection of files used.
274     llvm::DenseMap<const char *, unsigned> Files;
275 
276     typedef llvm::DenseMap<const void *, std::pair<unsigned, StringRef> >
277     DiagFlagsTy;
278 
279     /// Map for uniquing strings.
280     DiagFlagsTy DiagFlags;
281 
282     /// Whether we have already started emission of any DIAG blocks. Once
283     /// this becomes \c true, we never close a DIAG block until we know that we're
284     /// starting another one or we're done.
285     bool EmittedAnyDiagBlocks;
286 
287     /// Engine for emitting diagnostics about the diagnostics.
288     std::unique_ptr<DiagnosticsEngine> MetaDiagnostics;
289   };
290 
291   /// State shared among the various clones of this diagnostic consumer.
292   std::shared_ptr<SharedState> State;
293 };
294 } // end anonymous namespace
295 
296 namespace clang {
297 namespace serialized_diags {
298 std::unique_ptr<DiagnosticConsumer>
299 create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords) {
300   return std::make_unique<SDiagsWriter>(OutputFile, Diags, MergeChildRecords);
301 }
302 
303 } // end namespace serialized_diags
304 } // end namespace clang
305 
306 //===----------------------------------------------------------------------===//
307 // Serialization methods.
308 //===----------------------------------------------------------------------===//
309 
310 /// Emits a block ID in the BLOCKINFO block.
311 static void EmitBlockID(unsigned ID, const char *Name,
312                         llvm::BitstreamWriter &Stream,
313                         RecordDataImpl &Record) {
314   Record.clear();
315   Record.push_back(ID);
316   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
317 
318   // Emit the block name if present.
319   if (!Name || Name[0] == 0)
320     return;
321 
322   Record.clear();
323 
324   while (*Name)
325     Record.push_back(*Name++);
326 
327   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
328 }
329 
330 /// Emits a record ID in the BLOCKINFO block.
331 static void EmitRecordID(unsigned ID, const char *Name,
332                          llvm::BitstreamWriter &Stream,
333                          RecordDataImpl &Record){
334   Record.clear();
335   Record.push_back(ID);
336 
337   while (*Name)
338     Record.push_back(*Name++);
339 
340   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
341 }
342 
343 void SDiagsWriter::AddLocToRecord(FullSourceLoc Loc, PresumedLoc PLoc,
344                                   RecordDataImpl &Record, unsigned TokSize) {
345   if (PLoc.isInvalid()) {
346     // Emit a "sentinel" location.
347     Record.push_back((unsigned)0); // File.
348     Record.push_back((unsigned)0); // Line.
349     Record.push_back((unsigned)0); // Column.
350     Record.push_back((unsigned)0); // Offset.
351     return;
352   }
353 
354   Record.push_back(getEmitFile(PLoc.getFilename()));
355   Record.push_back(PLoc.getLine());
356   Record.push_back(PLoc.getColumn()+TokSize);
357   Record.push_back(Loc.getFileOffset());
358 }
359 
360 void SDiagsWriter::AddCharSourceRangeToRecord(CharSourceRange Range,
361                                               RecordDataImpl &Record,
362                                               const SourceManager &SM) {
363   AddLocToRecord(FullSourceLoc(Range.getBegin(), SM), Record);
364   unsigned TokSize = 0;
365   if (Range.isTokenRange())
366     TokSize = Lexer::MeasureTokenLength(Range.getEnd(),
367                                         SM, *LangOpts);
368 
369   AddLocToRecord(FullSourceLoc(Range.getEnd(), SM), Record, TokSize);
370 }
371 
372 unsigned SDiagsWriter::getEmitFile(const char *FileName){
373   if (!FileName)
374     return 0;
375 
376   unsigned &entry = State->Files[FileName];
377   if (entry)
378     return entry;
379 
380   // Lazily generate the record for the file.
381   entry = State->Files.size();
382   StringRef Name(FileName);
383   RecordData::value_type Record[] = {RECORD_FILENAME, entry, 0 /* For legacy */,
384                                      0 /* For legacy */, Name.size()};
385   State->Stream.EmitRecordWithBlob(State->Abbrevs.get(RECORD_FILENAME), Record,
386                                    Name);
387 
388   return entry;
389 }
390 
391 void SDiagsWriter::EmitCharSourceRange(CharSourceRange R,
392                                        const SourceManager &SM) {
393   State->Record.clear();
394   State->Record.push_back(RECORD_SOURCE_RANGE);
395   AddCharSourceRangeToRecord(R, State->Record, SM);
396   State->Stream.EmitRecordWithAbbrev(State->Abbrevs.get(RECORD_SOURCE_RANGE),
397                                      State->Record);
398 }
399 
400 /// Emits the preamble of the diagnostics file.
401 void SDiagsWriter::EmitPreamble() {
402   // Emit the file header.
403   State->Stream.Emit((unsigned)'D', 8);
404   State->Stream.Emit((unsigned)'I', 8);
405   State->Stream.Emit((unsigned)'A', 8);
406   State->Stream.Emit((unsigned)'G', 8);
407 
408   EmitBlockInfoBlock();
409   EmitMetaBlock();
410 }
411 
412 static void AddSourceLocationAbbrev(llvm::BitCodeAbbrev &Abbrev) {
413   using namespace llvm;
414   Abbrev.Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // File ID.
415   Abbrev.Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Line.
416   Abbrev.Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Column.
417   Abbrev.Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Offset;
418 }
419 
420 static void AddRangeLocationAbbrev(llvm::BitCodeAbbrev &Abbrev) {
421   AddSourceLocationAbbrev(Abbrev);
422   AddSourceLocationAbbrev(Abbrev);
423 }
424 
425 void SDiagsWriter::EmitBlockInfoBlock() {
426   State->Stream.EnterBlockInfoBlock();
427 
428   using namespace llvm;
429   llvm::BitstreamWriter &Stream = State->Stream;
430   RecordData &Record = State->Record;
431   AbbreviationMap &Abbrevs = State->Abbrevs;
432 
433   // ==---------------------------------------------------------------------==//
434   // The subsequent records and Abbrevs are for the "Meta" block.
435   // ==---------------------------------------------------------------------==//
436 
437   EmitBlockID(BLOCK_META, "Meta", Stream, Record);
438   EmitRecordID(RECORD_VERSION, "Version", Stream, Record);
439   auto Abbrev = std::make_shared<BitCodeAbbrev>();
440   Abbrev->Add(BitCodeAbbrevOp(RECORD_VERSION));
441   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
442   Abbrevs.set(RECORD_VERSION, Stream.EmitBlockInfoAbbrev(BLOCK_META, Abbrev));
443 
444   // ==---------------------------------------------------------------------==//
445   // The subsequent records and Abbrevs are for the "Diagnostic" block.
446   // ==---------------------------------------------------------------------==//
447 
448   EmitBlockID(BLOCK_DIAG, "Diag", Stream, Record);
449   EmitRecordID(RECORD_DIAG, "DiagInfo", Stream, Record);
450   EmitRecordID(RECORD_SOURCE_RANGE, "SrcRange", Stream, Record);
451   EmitRecordID(RECORD_CATEGORY, "CatName", Stream, Record);
452   EmitRecordID(RECORD_DIAG_FLAG, "DiagFlag", Stream, Record);
453   EmitRecordID(RECORD_FILENAME, "FileName", Stream, Record);
454   EmitRecordID(RECORD_FIXIT, "FixIt", Stream, Record);
455 
456   // Emit abbreviation for RECORD_DIAG.
457   Abbrev = std::make_shared<BitCodeAbbrev>();
458   Abbrev->Add(BitCodeAbbrevOp(RECORD_DIAG));
459   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // Diag level.
460   AddSourceLocationAbbrev(*Abbrev);
461   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Category.
462   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped Diag ID.
463   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // Text size.
464   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Diagnostc text.
465   Abbrevs.set(RECORD_DIAG, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
466 
467   // Emit abbreviation for RECORD_CATEGORY.
468   Abbrev = std::make_shared<BitCodeAbbrev>();
469   Abbrev->Add(BitCodeAbbrevOp(RECORD_CATEGORY));
470   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Category ID.
471   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));  // Text size.
472   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // Category text.
473   Abbrevs.set(RECORD_CATEGORY, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
474 
475   // Emit abbreviation for RECORD_SOURCE_RANGE.
476   Abbrev = std::make_shared<BitCodeAbbrev>();
477   Abbrev->Add(BitCodeAbbrevOp(RECORD_SOURCE_RANGE));
478   AddRangeLocationAbbrev(*Abbrev);
479   Abbrevs.set(RECORD_SOURCE_RANGE,
480               Stream.EmitBlockInfoAbbrev(BLOCK_DIAG, Abbrev));
481 
482   // Emit the abbreviation for RECORD_DIAG_FLAG.
483   Abbrev = std::make_shared<BitCodeAbbrev>();
484   Abbrev->Add(BitCodeAbbrevOp(RECORD_DIAG_FLAG));
485   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped Diag ID.
486   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
487   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Flag name text.
488   Abbrevs.set(RECORD_DIAG_FLAG, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
489                                                            Abbrev));
490 
491   // Emit the abbreviation for RECORD_FILENAME.
492   Abbrev = std::make_shared<BitCodeAbbrev>();
493   Abbrev->Add(BitCodeAbbrevOp(RECORD_FILENAME));
494   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 10)); // Mapped file ID.
495   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Size.
496   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Modification time.
497   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
498   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name text.
499   Abbrevs.set(RECORD_FILENAME, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
500                                                           Abbrev));
501 
502   // Emit the abbreviation for RECORD_FIXIT.
503   Abbrev = std::make_shared<BitCodeAbbrev>();
504   Abbrev->Add(BitCodeAbbrevOp(RECORD_FIXIT));
505   AddRangeLocationAbbrev(*Abbrev);
506   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Text size.
507   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // FixIt text.
508   Abbrevs.set(RECORD_FIXIT, Stream.EmitBlockInfoAbbrev(BLOCK_DIAG,
509                                                        Abbrev));
510 
511   Stream.ExitBlock();
512 }
513 
514 void SDiagsWriter::EmitMetaBlock() {
515   llvm::BitstreamWriter &Stream = State->Stream;
516   AbbreviationMap &Abbrevs = State->Abbrevs;
517 
518   Stream.EnterSubblock(BLOCK_META, 3);
519   RecordData::value_type Record[] = {RECORD_VERSION, VersionNumber};
520   Stream.EmitRecordWithAbbrev(Abbrevs.get(RECORD_VERSION), Record);
521   Stream.ExitBlock();
522 }
523 
524 unsigned SDiagsWriter::getEmitCategory(unsigned int category) {
525   if (!State->Categories.insert(category).second)
526     return category;
527 
528   // We use a local version of 'Record' so that we can be generating
529   // another record when we lazily generate one for the category entry.
530   StringRef catName = DiagnosticIDs::getCategoryNameFromID(category);
531   RecordData::value_type Record[] = {RECORD_CATEGORY, category, catName.size()};
532   State->Stream.EmitRecordWithBlob(State->Abbrevs.get(RECORD_CATEGORY), Record,
533                                    catName);
534 
535   return category;
536 }
537 
538 unsigned SDiagsWriter::getEmitDiagnosticFlag(DiagnosticsEngine::Level DiagLevel,
539                                              const Diagnostic *Diag) {
540   if (!Diag || DiagLevel == DiagnosticsEngine::Note)
541     return 0; // No flag for notes.
542 
543   StringRef FlagName =
544       Diag->getDiags()->getDiagnosticIDs()->getWarningOptionForDiag(
545           Diag->getID());
546   return getEmitDiagnosticFlag(FlagName);
547 }
548 
549 unsigned SDiagsWriter::getEmitDiagnosticFlag(StringRef FlagName) {
550   if (FlagName.empty())
551     return 0;
552 
553   // Here we assume that FlagName points to static data whose pointer
554   // value is fixed.  This allows us to unique by diagnostic groups.
555   const void *data = FlagName.data();
556   std::pair<unsigned, StringRef> &entry = State->DiagFlags[data];
557   if (entry.first == 0) {
558     entry.first = State->DiagFlags.size();
559     entry.second = FlagName;
560 
561     // Lazily emit the string in a separate record.
562     RecordData::value_type Record[] = {RECORD_DIAG_FLAG, entry.first,
563                                        FlagName.size()};
564     State->Stream.EmitRecordWithBlob(State->Abbrevs.get(RECORD_DIAG_FLAG),
565                                      Record, FlagName);
566   }
567 
568   return entry.first;
569 }
570 
571 void SDiagsWriter::HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
572                                     const Diagnostic &Info) {
573   assert(!IsFinishing &&
574          "Received a diagnostic after we've already started teardown.");
575   if (IsFinishing) {
576     SmallString<256> diagnostic;
577     Info.FormatDiagnostic(diagnostic);
578     getMetaDiags()->Report(
579         diag::warn_fe_serialized_diag_failure_during_finalization)
580         << diagnostic;
581     return;
582   }
583 
584   // Enter the block for a non-note diagnostic immediately, rather than waiting
585   // for beginDiagnostic, in case associated notes are emitted before we get
586   // there.
587   if (DiagLevel != DiagnosticsEngine::Note) {
588     if (State->EmittedAnyDiagBlocks)
589       ExitDiagBlock();
590 
591     EnterDiagBlock();
592     State->EmittedAnyDiagBlocks = true;
593   }
594 
595   // Compute the diagnostic text.
596   State->diagBuf.clear();
597   Info.FormatDiagnostic(State->diagBuf);
598 
599   if (Info.getLocation().isInvalid()) {
600     // Special-case diagnostics with no location. We may not have entered a
601     // source file in this case, so we can't use the normal DiagnosticsRenderer
602     // machinery.
603 
604     // Make sure we bracket all notes as "sub-diagnostics".  This matches
605     // the behavior in SDiagsRenderer::emitDiagnostic().
606     if (DiagLevel == DiagnosticsEngine::Note)
607       EnterDiagBlock();
608 
609     EmitDiagnosticMessage(FullSourceLoc(), PresumedLoc(), DiagLevel,
610                           State->diagBuf, &Info);
611 
612     if (DiagLevel == DiagnosticsEngine::Note)
613       ExitDiagBlock();
614 
615     return;
616   }
617 
618   assert(Info.hasSourceManager() && LangOpts &&
619          "Unexpected diagnostic with valid location outside of a source file");
620   SDiagsRenderer Renderer(*this, *LangOpts, &*State->DiagOpts);
621   Renderer.emitDiagnostic(
622       FullSourceLoc(Info.getLocation(), Info.getSourceManager()), DiagLevel,
623       State->diagBuf, Info.getRanges(), Info.getFixItHints(), &Info);
624 }
625 
626 static serialized_diags::Level getStableLevel(DiagnosticsEngine::Level Level) {
627   switch (Level) {
628 #define CASE(X) case DiagnosticsEngine::X: return serialized_diags::X;
629   CASE(Ignored)
630   CASE(Note)
631   CASE(Remark)
632   CASE(Warning)
633   CASE(Error)
634   CASE(Fatal)
635 #undef CASE
636   }
637 
638   llvm_unreachable("invalid diagnostic level");
639 }
640 
641 void SDiagsWriter::EmitDiagnosticMessage(FullSourceLoc Loc, PresumedLoc PLoc,
642                                          DiagnosticsEngine::Level Level,
643                                          StringRef Message,
644                                          DiagOrStoredDiag D) {
645   llvm::BitstreamWriter &Stream = State->Stream;
646   RecordData &Record = State->Record;
647   AbbreviationMap &Abbrevs = State->Abbrevs;
648 
649   // Emit the RECORD_DIAG record.
650   Record.clear();
651   Record.push_back(RECORD_DIAG);
652   Record.push_back(getStableLevel(Level));
653   AddLocToRecord(Loc, PLoc, Record);
654 
655   if (const Diagnostic *Info = dyn_cast_if_present<const Diagnostic *>(D)) {
656     // Emit the category string lazily and get the category ID.
657     unsigned DiagID = DiagnosticIDs::getCategoryNumberForDiag(Info->getID());
658     Record.push_back(getEmitCategory(DiagID));
659     // Emit the diagnostic flag string lazily and get the mapped ID.
660     Record.push_back(getEmitDiagnosticFlag(Level, Info));
661   } else {
662     Record.push_back(getEmitCategory());
663     Record.push_back(getEmitDiagnosticFlag(Level));
664   }
665 
666   Record.push_back(Message.size());
667   Stream.EmitRecordWithBlob(Abbrevs.get(RECORD_DIAG), Record, Message);
668 }
669 
670 void SDiagsRenderer::emitDiagnosticMessage(
671     FullSourceLoc Loc, PresumedLoc PLoc, DiagnosticsEngine::Level Level,
672     StringRef Message, ArrayRef<clang::CharSourceRange> Ranges,
673     DiagOrStoredDiag D) {
674   Writer.EmitDiagnosticMessage(Loc, PLoc, Level, Message, D);
675 }
676 
677 void SDiagsWriter::EnterDiagBlock() {
678   State->Stream.EnterSubblock(BLOCK_DIAG, 4);
679 }
680 
681 void SDiagsWriter::ExitDiagBlock() {
682   State->Stream.ExitBlock();
683 }
684 
685 void SDiagsRenderer::beginDiagnostic(DiagOrStoredDiag D,
686                                      DiagnosticsEngine::Level Level) {
687   if (Level == DiagnosticsEngine::Note)
688     Writer.EnterDiagBlock();
689 }
690 
691 void SDiagsRenderer::endDiagnostic(DiagOrStoredDiag D,
692                                    DiagnosticsEngine::Level Level) {
693   // Only end note diagnostics here, because we can't be sure when we've seen
694   // the last note associated with a non-note diagnostic.
695   if (Level == DiagnosticsEngine::Note)
696     Writer.ExitDiagBlock();
697 }
698 
699 void SDiagsWriter::EmitCodeContext(SmallVectorImpl<CharSourceRange> &Ranges,
700                                    ArrayRef<FixItHint> Hints,
701                                    const SourceManager &SM) {
702   llvm::BitstreamWriter &Stream = State->Stream;
703   RecordData &Record = State->Record;
704   AbbreviationMap &Abbrevs = State->Abbrevs;
705 
706   // Emit Source Ranges.
707   for (ArrayRef<CharSourceRange>::iterator I = Ranges.begin(), E = Ranges.end();
708        I != E; ++I)
709     if (I->isValid())
710       EmitCharSourceRange(*I, SM);
711 
712   // Emit FixIts.
713   for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
714        I != E; ++I) {
715     const FixItHint &Fix = *I;
716     if (Fix.isNull())
717       continue;
718     Record.clear();
719     Record.push_back(RECORD_FIXIT);
720     AddCharSourceRangeToRecord(Fix.RemoveRange, Record, SM);
721     Record.push_back(Fix.CodeToInsert.size());
722     Stream.EmitRecordWithBlob(Abbrevs.get(RECORD_FIXIT), Record,
723                               Fix.CodeToInsert);
724   }
725 }
726 
727 void SDiagsRenderer::emitCodeContext(FullSourceLoc Loc,
728                                      DiagnosticsEngine::Level Level,
729                                      SmallVectorImpl<CharSourceRange> &Ranges,
730                                      ArrayRef<FixItHint> Hints) {
731   Writer.EmitCodeContext(Ranges, Hints, Loc.getManager());
732 }
733 
734 void SDiagsRenderer::emitNote(FullSourceLoc Loc, StringRef Message) {
735   Writer.EnterDiagBlock();
736   PresumedLoc PLoc = Loc.hasManager() ? Loc.getPresumedLoc() : PresumedLoc();
737   Writer.EmitDiagnosticMessage(Loc, PLoc, DiagnosticsEngine::Note, Message,
738                                DiagOrStoredDiag());
739   Writer.ExitDiagBlock();
740 }
741 
742 DiagnosticsEngine *SDiagsWriter::getMetaDiags() {
743   // FIXME: It's slightly absurd to create a new diagnostics engine here, but
744   // the other options that are available today are worse:
745   //
746   // 1. Teach DiagnosticsConsumers to emit diagnostics to the engine they are a
747   //    part of. The DiagnosticsEngine would need to know not to send
748   //    diagnostics back to the consumer that failed. This would require us to
749   //    rework ChainedDiagnosticsConsumer and teach the engine about multiple
750   //    consumers, which is difficult today because most APIs interface with
751   //    consumers rather than the engine itself.
752   //
753   // 2. Pass a DiagnosticsEngine to SDiagsWriter on creation - this would need
754   //    to be distinct from the engine the writer was being added to and would
755   //    normally not be used.
756   if (!State->MetaDiagnostics) {
757     IntrusiveRefCntPtr<DiagnosticIDs> IDs(new DiagnosticIDs());
758     auto Client =
759         new TextDiagnosticPrinter(llvm::errs(), State->DiagOpts.get());
760     State->MetaDiagnostics = std::make_unique<DiagnosticsEngine>(
761         IDs, State->DiagOpts.get(), Client);
762   }
763   return State->MetaDiagnostics.get();
764 }
765 
766 void SDiagsWriter::RemoveOldDiagnostics() {
767   if (!llvm::sys::fs::remove(State->OutputFile))
768     return;
769 
770   getMetaDiags()->Report(diag::warn_fe_serialized_diag_merge_failure);
771   // Disable merging child records, as whatever is in this file may be
772   // misleading.
773   MergeChildRecords = false;
774 }
775 
776 void SDiagsWriter::finish() {
777   assert(!IsFinishing);
778   IsFinishing = true;
779 
780   // The original instance is responsible for writing the file.
781   if (!OriginalInstance)
782     return;
783 
784   // Finish off any diagnostic we were in the process of emitting.
785   if (State->EmittedAnyDiagBlocks)
786     ExitDiagBlock();
787 
788   if (MergeChildRecords) {
789     if (!State->EmittedAnyDiagBlocks)
790       // We have no diagnostics of our own, so we can just leave the child
791       // process' output alone
792       return;
793 
794     if (llvm::sys::fs::exists(State->OutputFile))
795       if (SDiagsMerger(*this).mergeRecordsFromFile(State->OutputFile.c_str()))
796         getMetaDiags()->Report(diag::warn_fe_serialized_diag_merge_failure);
797   }
798 
799   std::error_code EC;
800   auto OS = std::make_unique<llvm::raw_fd_ostream>(State->OutputFile.c_str(),
801                                                     EC, llvm::sys::fs::OF_None);
802   if (EC) {
803     getMetaDiags()->Report(diag::warn_fe_serialized_diag_failure)
804         << State->OutputFile << EC.message();
805     OS->clear_error();
806     return;
807   }
808 
809   // Write the generated bitstream to "Out".
810   OS->write((char *)&State->Buffer.front(), State->Buffer.size());
811   OS->flush();
812 
813   assert(!OS->has_error());
814   if (OS->has_error()) {
815     getMetaDiags()->Report(diag::warn_fe_serialized_diag_failure)
816         << State->OutputFile << OS->error().message();
817     OS->clear_error();
818   }
819 }
820 
821 std::error_code SDiagsMerger::visitStartOfDiagnostic() {
822   Writer.EnterDiagBlock();
823   return std::error_code();
824 }
825 
826 std::error_code SDiagsMerger::visitEndOfDiagnostic() {
827   Writer.ExitDiagBlock();
828   return std::error_code();
829 }
830 
831 std::error_code
832 SDiagsMerger::visitSourceRangeRecord(const serialized_diags::Location &Start,
833                                      const serialized_diags::Location &End) {
834   RecordData::value_type Record[] = {
835       RECORD_SOURCE_RANGE, FileLookup[Start.FileID], Start.Line, Start.Col,
836       Start.Offset, FileLookup[End.FileID], End.Line, End.Col, End.Offset};
837   Writer.State->Stream.EmitRecordWithAbbrev(
838       Writer.State->Abbrevs.get(RECORD_SOURCE_RANGE), Record);
839   return std::error_code();
840 }
841 
842 std::error_code SDiagsMerger::visitDiagnosticRecord(
843     unsigned Severity, const serialized_diags::Location &Location,
844     unsigned Category, unsigned Flag, StringRef Message) {
845   RecordData::value_type Record[] = {
846       RECORD_DIAG, Severity, FileLookup[Location.FileID], Location.Line,
847       Location.Col, Location.Offset, CategoryLookup[Category],
848       Flag ? DiagFlagLookup[Flag] : 0, Message.size()};
849 
850   Writer.State->Stream.EmitRecordWithBlob(
851       Writer.State->Abbrevs.get(RECORD_DIAG), Record, Message);
852   return std::error_code();
853 }
854 
855 std::error_code
856 SDiagsMerger::visitFixitRecord(const serialized_diags::Location &Start,
857                                const serialized_diags::Location &End,
858                                StringRef Text) {
859   RecordData::value_type Record[] = {RECORD_FIXIT, FileLookup[Start.FileID],
860                                      Start.Line, Start.Col, Start.Offset,
861                                      FileLookup[End.FileID], End.Line, End.Col,
862                                      End.Offset, Text.size()};
863 
864   Writer.State->Stream.EmitRecordWithBlob(
865       Writer.State->Abbrevs.get(RECORD_FIXIT), Record, Text);
866   return std::error_code();
867 }
868 
869 std::error_code SDiagsMerger::visitFilenameRecord(unsigned ID, unsigned Size,
870                                                   unsigned Timestamp,
871                                                   StringRef Name) {
872   FileLookup[ID] = Writer.getEmitFile(Name.str().c_str());
873   return std::error_code();
874 }
875 
876 std::error_code SDiagsMerger::visitCategoryRecord(unsigned ID, StringRef Name) {
877   CategoryLookup[ID] = Writer.getEmitCategory(ID);
878   return std::error_code();
879 }
880 
881 std::error_code SDiagsMerger::visitDiagFlagRecord(unsigned ID, StringRef Name) {
882   DiagFlagLookup[ID] = Writer.getEmitDiagnosticFlag(Name);
883   return std::error_code();
884 }
885