1//===--- Diagnostics.cpp -----------------------------------------*- 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#include "Diagnostics.h"
10#include "../clang-tidy/ClangTidyDiagnosticConsumer.h"
11#include "Compiler.h"
12#include "Protocol.h"
13#include "SourceCode.h"
14#include "support/Logger.h"
15#include "clang/Basic/AllDiagnostics.h" // IWYU pragma: keep
16#include "clang/Basic/Diagnostic.h"
17#include "clang/Basic/DiagnosticIDs.h"
18#include "clang/Basic/LLVM.h"
19#include "clang/Basic/SourceLocation.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Basic/TokenKinds.h"
22#include "clang/Lex/Lexer.h"
23#include "clang/Lex/Token.h"
24#include "llvm/ADT/ArrayRef.h"
25#include "llvm/ADT/DenseSet.h"
26#include "llvm/ADT/STLExtras.h"
27#include "llvm/ADT/STLFunctionalExtras.h"
28#include "llvm/ADT/ScopeExit.h"
29#include "llvm/ADT/SmallString.h"
30#include "llvm/ADT/SmallVector.h"
31#include "llvm/ADT/StringExtras.h"
32#include "llvm/ADT/StringRef.h"
33#include "llvm/ADT/StringSet.h"
34#include "llvm/ADT/Twine.h"
35#include "llvm/Support/ErrorHandling.h"
36#include "llvm/Support/FormatVariadic.h"
37#include "llvm/Support/Path.h"
38#include "llvm/Support/SourceMgr.h"
39#include "llvm/Support/raw_ostream.h"
40#include <algorithm>
41#include <cassert>
42#include <optional>
43#include <set>
44#include <string>
45#include <tuple>
46#include <utility>
47#include <vector>
48
49namespace clang {
50namespace clangd {
51namespace {
52
53const char *getDiagnosticCode(unsigned ID) {
54 switch (ID) {
55#define DIAG(ENUM, CLASS, DEFAULT_MAPPING, DESC, GROPU, SFINAE, NOWERROR, \
56 SHOWINSYSHEADER, SHOWINSYSMACRO, DEFERRABLE, CATEGORY) \
57 case clang::diag::ENUM: \
58 return #ENUM;
59#include "clang/Basic/DiagnosticASTKinds.inc"
60#include "clang/Basic/DiagnosticAnalysisKinds.inc"
61#include "clang/Basic/DiagnosticCommentKinds.inc"
62#include "clang/Basic/DiagnosticCommonKinds.inc"
63#include "clang/Basic/DiagnosticDriverKinds.inc"
64#include "clang/Basic/DiagnosticFrontendKinds.inc"
65#include "clang/Basic/DiagnosticLexKinds.inc"
66#include "clang/Basic/DiagnosticParseKinds.inc"
67#include "clang/Basic/DiagnosticRefactoringKinds.inc"
68#include "clang/Basic/DiagnosticSemaKinds.inc"
69#include "clang/Basic/DiagnosticSerializationKinds.inc"
70#undef DIAG
71 default:
72 return nullptr;
73 }
74}
75
76bool mentionsMainFile(const Diag &D) {
77 if (D.InsideMainFile)
78 return true;
79 // Fixes are always in the main file.
80 if (!D.Fixes.empty())
81 return true;
82 for (auto &N : D.Notes) {
83 if (N.InsideMainFile)
84 return true;
85 }
86 return false;
87}
88
89bool isExcluded(unsigned DiagID) {
90 // clang will always fail parsing MS ASM, we don't link in desc + asm parser.
91 if (DiagID == clang::diag::err_msasm_unable_to_create_target ||
92 DiagID == clang::diag::err_msasm_unsupported_arch)
93 return true;
94 return false;
95}
96
97// Checks whether a location is within a half-open range.
98// Note that clang also uses closed source ranges, which this can't handle!
99bool locationInRange(SourceLocation L, CharSourceRange R,
100 const SourceManager &M) {
101 assert(R.isCharRange());
102 if (!R.isValid() || M.getFileID(SpellingLoc: R.getBegin()) != M.getFileID(SpellingLoc: R.getEnd()) ||
103 M.getFileID(SpellingLoc: R.getBegin()) != M.getFileID(SpellingLoc: L))
104 return false;
105 return L != R.getEnd() && M.isPointWithin(Location: L, Start: R.getBegin(), End: R.getEnd());
106}
107
108// Clang diags have a location (shown as ^) and 0 or more ranges (~~~~).
109// LSP needs a single range.
110std::optional<Range> diagnosticRange(const clang::Diagnostic &D,
111 const LangOptions &L) {
112 auto &M = D.getSourceManager();
113 auto PatchedRange = [&M](CharSourceRange &R) {
114 R.setBegin(translatePreamblePatchLocation(Loc: R.getBegin(), SM: M));
115 R.setEnd(translatePreamblePatchLocation(Loc: R.getEnd(), SM: M));
116 return R;
117 };
118 auto Loc = M.getFileLoc(Loc: D.getLocation());
119 for (const auto &CR : D.getRanges()) {
120 auto R = Lexer::makeFileCharRange(CR, M, L);
121 if (locationInRange(Loc, R, M))
122 return halfOpenToRange(M, PatchedRange(R));
123 }
124 // The range may be given as a fixit hint instead.
125 for (const auto &F : D.getFixItHints()) {
126 auto R = Lexer::makeFileCharRange(Range: F.RemoveRange, SM: M, LangOpts: L);
127 if (locationInRange(L: Loc, R, M))
128 return halfOpenToRange(SM: M, R: PatchedRange(R));
129 }
130 // Source locations from stale preambles might become OOB.
131 // FIXME: These diagnostics might point to wrong locations even when they're
132 // not OOB.
133 auto [FID, Offset] = M.getDecomposedLoc(Loc);
134 if (Offset > M.getBufferData(FID).size())
135 return std::nullopt;
136 // If the token at the location is not a comment, we use the token.
137 // If we can't get the token at the location, fall back to using the location
138 auto R = CharSourceRange::getCharRange(R: Loc);
139 Token Tok;
140 if (!Lexer::getRawToken(Loc, Result&: Tok, SM: M, LangOpts: L, IgnoreWhiteSpace: true) && Tok.isNot(K: tok::comment))
141 R = CharSourceRange::getTokenRange(B: Tok.getLocation(), E: Tok.getEndLoc());
142 return halfOpenToRange(SM: M, R: PatchedRange(R));
143}
144
145// Try to find a location in the main-file to report the diagnostic D.
146// Returns a description like "in included file", or nullptr on failure.
147const char *getMainFileRange(const Diag &D, const SourceManager &SM,
148 SourceLocation DiagLoc, Range &R) {
149 // Look for a note in the main file indicating template instantiation.
150 for (const auto &N : D.Notes) {
151 if (N.InsideMainFile) {
152 switch (N.ID) {
153 case diag::note_template_class_instantiation_was_here:
154 case diag::note_template_class_explicit_specialization_was_here:
155 case diag::note_template_class_instantiation_here:
156 case diag::note_template_member_class_here:
157 case diag::note_template_member_function_here:
158 case diag::note_function_template_spec_here:
159 case diag::note_template_static_data_member_def_here:
160 case diag::note_template_variable_def_here:
161 case diag::note_template_enum_def_here:
162 case diag::note_template_nsdmi_here:
163 case diag::note_template_type_alias_instantiation_here:
164 case diag::note_template_exception_spec_instantiation_here:
165 case diag::note_template_requirement_instantiation_here:
166 case diag::note_evaluating_exception_spec_here:
167 case diag::note_default_arg_instantiation_here:
168 case diag::note_default_function_arg_instantiation_here:
169 case diag::note_explicit_template_arg_substitution_here:
170 case diag::note_function_template_deduction_instantiation_here:
171 case diag::note_deduced_template_arg_substitution_here:
172 case diag::note_prior_template_arg_substitution:
173 case diag::note_template_default_arg_checking:
174 case diag::note_concept_specialization_here:
175 case diag::note_nested_requirement_here:
176 case diag::note_checking_constraints_for_template_id_here:
177 case diag::note_checking_constraints_for_var_spec_id_here:
178 case diag::note_checking_constraints_for_class_spec_id_here:
179 case diag::note_checking_constraints_for_function_here:
180 case diag::note_constraint_substitution_here:
181 case diag::note_constraint_normalization_here:
182 case diag::note_parameter_mapping_substitution_here:
183 R = N.Range;
184 return "in template";
185 default:
186 break;
187 }
188 }
189 }
190 // Look for where the file with the error was #included.
191 auto GetIncludeLoc = [&SM](SourceLocation SLoc) {
192 return SM.getIncludeLoc(FID: SM.getFileID(SpellingLoc: SLoc));
193 };
194 for (auto IncludeLocation = GetIncludeLoc(SM.getExpansionLoc(Loc: DiagLoc));
195 IncludeLocation.isValid();
196 IncludeLocation = GetIncludeLoc(IncludeLocation)) {
197 if (clangd::isInsideMainFile(Loc: IncludeLocation, SM)) {
198 R.start = sourceLocToPosition(SM, Loc: IncludeLocation);
199 R.end = sourceLocToPosition(
200 SM,
201 Loc: Lexer::getLocForEndOfToken(Loc: IncludeLocation, Offset: 0, SM, LangOpts: LangOptions()));
202 return "in included file";
203 }
204 }
205 return nullptr;
206}
207
208// Place the diagnostic the main file, rather than the header, if possible:
209// - for errors in included files, use the #include location
210// - for errors in template instantiation, use the instantiation location
211// In both cases, add the original header location as a note.
212bool tryMoveToMainFile(Diag &D, FullSourceLoc DiagLoc) {
213 const SourceManager &SM = DiagLoc.getManager();
214 DiagLoc = DiagLoc.getExpansionLoc();
215 Range R;
216 const char *Prefix = getMainFileRange(D, SM, DiagLoc, R);
217 if (!Prefix)
218 return false;
219
220 // Add a note that will point to real diagnostic.
221 auto FE = *SM.getFileEntryRefForID(FID: SM.getFileID(SpellingLoc: DiagLoc));
222 D.Notes.emplace(D.Notes.begin());
223 Note &N = D.Notes.front();
224 N.AbsFile = std::string(FE.getFileEntry().tryGetRealPathName());
225 N.File = std::string(FE.getName());
226 N.Message = "error occurred here";
227 N.Range = D.Range;
228
229 // Update diag to point at include inside main file.
230 D.File = SM.getFileEntryRefForID(FID: SM.getMainFileID())->getName().str();
231 D.Range = std::move(R);
232 D.InsideMainFile = true;
233 // Update message to mention original file.
234 D.Message = llvm::formatv("{0}: {1}", Prefix, D.Message);
235 return true;
236}
237
238bool isNote(DiagnosticsEngine::Level L) {
239 return L == DiagnosticsEngine::Note || L == DiagnosticsEngine::Remark;
240}
241
242llvm::StringRef diagLeveltoString(DiagnosticsEngine::Level Lvl) {
243 switch (Lvl) {
244 case DiagnosticsEngine::Ignored:
245 return "ignored";
246 case DiagnosticsEngine::Note:
247 return "note";
248 case DiagnosticsEngine::Remark:
249 return "remark";
250 case DiagnosticsEngine::Warning:
251 return "warning";
252 case DiagnosticsEngine::Error:
253 return "error";
254 case DiagnosticsEngine::Fatal:
255 return "fatal error";
256 }
257 llvm_unreachable("unhandled DiagnosticsEngine::Level");
258}
259
260/// Prints a single diagnostic in a clang-like manner, the output includes
261/// location, severity and error message. An example of the output message is:
262///
263/// main.cpp:12:23: error: undeclared identifier
264///
265/// For main file we only print the basename and for all other files we print
266/// the filename on a separate line to provide a slightly more readable output
267/// in the editors:
268///
269/// dir1/dir2/dir3/../../dir4/header.h:12:23
270/// error: undeclared identifier
271void printDiag(llvm::raw_string_ostream &OS, const DiagBase &D) {
272 if (D.InsideMainFile) {
273 // Paths to main files are often taken from compile_command.json, where they
274 // are typically absolute. To reduce noise we print only basename for them,
275 // it should not be confusing and saves space.
276 OS << llvm::sys::path::filename(path: D.File) << ":";
277 } else {
278 OS << D.File << ":";
279 }
280 // Note +1 to line and character. clangd::Range is zero-based, but when
281 // printing for users we want one-based indexes.
282 auto Pos = D.Range.start;
283 OS << (Pos.line + 1) << ":" << (Pos.character + 1) << ":";
284 // The non-main-file paths are often too long, putting them on a separate
285 // line improves readability.
286 if (D.InsideMainFile)
287 OS << " ";
288 else
289 OS << "\n";
290 OS << diagLeveltoString(Lvl: D.Severity) << ": " << D.Message;
291}
292
293/// Capitalizes the first word in the diagnostic's message.
294std::string capitalize(std::string Message) {
295 if (!Message.empty())
296 Message[0] = llvm::toUpper(x: Message[0]);
297 return Message;
298}
299
300/// Returns a message sent to LSP for the main diagnostic in \p D.
301/// This message may include notes, if they're not emitted in some other way.
302/// Example output:
303///
304/// no matching function for call to 'foo'
305///
306/// main.cpp:3:5: note: candidate function not viable: requires 2 arguments
307///
308/// dir1/dir2/dir3/../../dir4/header.h:12:23
309/// note: candidate function not viable: requires 3 arguments
310std::string mainMessage(const Diag &D, const ClangdDiagnosticOptions &Opts) {
311 std::string Result;
312 llvm::raw_string_ostream OS(Result);
313 OS << D.Message;
314 if (Opts.DisplayFixesCount && !D.Fixes.empty())
315 OS << " (" << (D.Fixes.size() > 1 ? "fixes" : "fix") << " available)";
316 // If notes aren't emitted as structured info, add them to the message.
317 if (!Opts.EmitRelatedLocations)
318 for (auto &Note : D.Notes) {
319 OS << "\n\n";
320 printDiag(OS, Note);
321 }
322 OS.flush();
323 return capitalize(std::move(Result));
324}
325
326/// Returns a message sent to LSP for the note of the main diagnostic.
327std::string noteMessage(const Diag &Main, const DiagBase &Note,
328 const ClangdDiagnosticOptions &Opts) {
329 std::string Result;
330 llvm::raw_string_ostream OS(Result);
331 OS << Note.Message;
332 // If the client doesn't support structured links between the note and the
333 // original diagnostic, then emit the main diagnostic to give context.
334 if (!Opts.EmitRelatedLocations) {
335 OS << "\n\n";
336 printDiag(OS, D: Main);
337 }
338 OS.flush();
339 return capitalize(std::move(Result));
340}
341
342void setTags(clangd::Diag &D) {
343 static const auto *DeprecatedDiags = new llvm::DenseSet<unsigned>{
344 diag::warn_access_decl_deprecated,
345 diag::warn_atl_uuid_deprecated,
346 diag::warn_deprecated,
347 diag::warn_deprecated_altivec_src_compat,
348 diag::warn_deprecated_comma_subscript,
349 diag::warn_deprecated_copy,
350 diag::warn_deprecated_copy_with_dtor,
351 diag::warn_deprecated_copy_with_user_provided_copy,
352 diag::warn_deprecated_copy_with_user_provided_dtor,
353 diag::warn_deprecated_def,
354 diag::warn_deprecated_increment_decrement_volatile,
355 diag::warn_deprecated_message,
356 diag::warn_deprecated_redundant_constexpr_static_def,
357 diag::warn_deprecated_register,
358 diag::warn_deprecated_simple_assign_volatile,
359 diag::warn_deprecated_string_literal_conversion,
360 diag::warn_deprecated_this_capture,
361 diag::warn_deprecated_volatile_param,
362 diag::warn_deprecated_volatile_return,
363 diag::warn_deprecated_volatile_structured_binding,
364 diag::warn_opencl_attr_deprecated_ignored,
365 diag::warn_property_method_deprecated,
366 diag::warn_vector_mode_deprecated,
367 };
368 static const auto *UnusedDiags = new llvm::DenseSet<unsigned>{
369 diag::warn_opencl_attr_deprecated_ignored,
370 diag::warn_pragma_attribute_unused,
371 diag::warn_unused_but_set_parameter,
372 diag::warn_unused_but_set_variable,
373 diag::warn_unused_comparison,
374 diag::warn_unused_const_variable,
375 diag::warn_unused_exception_param,
376 diag::warn_unused_function,
377 diag::warn_unused_label,
378 diag::warn_unused_lambda_capture,
379 diag::warn_unused_local_typedef,
380 diag::warn_unused_member_function,
381 diag::warn_unused_parameter,
382 diag::warn_unused_private_field,
383 diag::warn_unused_property_backing_ivar,
384 diag::warn_unused_template,
385 diag::warn_unused_variable,
386 };
387 if (DeprecatedDiags->contains(D.ID)) {
388 D.Tags.push_back(Elt: DiagnosticTag::Deprecated);
389 } else if (UnusedDiags->contains(D.ID)) {
390 D.Tags.push_back(Elt: DiagnosticTag::Unnecessary);
391 }
392 if (D.Source == Diag::ClangTidy) {
393 if (llvm::StringRef(D.Name).starts_with(Prefix: "misc-unused-"))
394 D.Tags.push_back(Elt: DiagnosticTag::Unnecessary);
395 if (llvm::StringRef(D.Name).starts_with(Prefix: "modernize-"))
396 D.Tags.push_back(Elt: DiagnosticTag::Deprecated);
397 }
398}
399} // namespace
400
401llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const DiagBase &D) {
402 OS << "[";
403 if (!D.InsideMainFile)
404 OS << D.File << ":";
405 OS << D.Range.start << "-" << D.Range.end << "] ";
406
407 return OS << D.Message;
408}
409
410llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Fix &F) {
411 OS << F.Message << " {";
412 const char *Sep = "";
413 for (const auto &Edit : F.Edits) {
414 OS << Sep << Edit;
415 Sep = ", ";
416 }
417 return OS << "}";
418}
419
420llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Diag &D) {
421 OS << static_cast<const DiagBase &>(D);
422 if (!D.Notes.empty()) {
423 OS << ", notes: {";
424 const char *Sep = "";
425 for (auto &Note : D.Notes) {
426 OS << Sep << Note;
427 Sep = ", ";
428 }
429 OS << "}";
430 }
431 if (!D.Fixes.empty()) {
432 OS << ", fixes: {";
433 const char *Sep = "";
434 for (auto &Fix : D.Fixes) {
435 OS << Sep << Fix;
436 Sep = ", ";
437 }
438 OS << "}";
439 }
440 return OS;
441}
442
443Diag toDiag(const llvm::SMDiagnostic &D, Diag::DiagSource Source) {
444 Diag Result;
445 Result.Message = D.getMessage().str();
446 switch (D.getKind()) {
447 case llvm::SourceMgr::DK_Error:
448 Result.Severity = DiagnosticsEngine::Error;
449 break;
450 case llvm::SourceMgr::DK_Warning:
451 Result.Severity = DiagnosticsEngine::Warning;
452 break;
453 default:
454 break;
455 }
456 Result.Source = Source;
457 Result.AbsFile = D.getFilename().str();
458 Result.InsideMainFile = D.getSourceMgr()->FindBufferContainingLoc(
459 Loc: D.getLoc()) == D.getSourceMgr()->getMainFileID();
460 if (D.getRanges().empty())
461 Result.Range = {.start: {.line: D.getLineNo() - 1, .character: D.getColumnNo()},
462 .end: {.line: D.getLineNo() - 1, .character: D.getColumnNo()}};
463 else
464 Result.Range = {.start: {.line: D.getLineNo() - 1, .character: (int)D.getRanges().front().first},
465 .end: {.line: D.getLineNo() - 1, .character: (int)D.getRanges().front().second}};
466 return Result;
467}
468
469void toLSPDiags(
470 const Diag &D, const URIForFile &File, const ClangdDiagnosticOptions &Opts,
471 llvm::function_ref<void(clangd::Diagnostic, llvm::ArrayRef<Fix>)> OutFn) {
472 clangd::Diagnostic Main;
473 Main.severity = getSeverity(L: D.Severity);
474 // We downgrade severity for certain noisy warnings, like deprecated
475 // declartions. These already have visible decorations inside the editor and
476 // most users find the extra clutter in the UI (gutter, minimap, diagnostics
477 // views) overwhelming.
478 if (D.Severity == DiagnosticsEngine::Warning) {
479 if (llvm::is_contained(D.Tags, DiagnosticTag::Deprecated))
480 Main.severity = getSeverity(L: DiagnosticsEngine::Remark);
481 }
482
483 // Main diagnostic should always refer to a range inside main file. If a
484 // diagnostic made it so for, it means either itself or one of its notes is
485 // inside main file. It's also possible that there's a fix in the main file,
486 // but we preserve fixes iff primary diagnostic is in the main file.
487 if (D.InsideMainFile) {
488 Main.range = D.Range;
489 } else {
490 auto It =
491 llvm::find_if(D.Notes, [](const Note &N) { return N.InsideMainFile; });
492 assert(It != D.Notes.end() &&
493 "neither the main diagnostic nor notes are inside main file");
494 Main.range = It->Range;
495 }
496
497 Main.code = D.Name;
498 if (auto URI = getDiagnosticDocURI(D.Source, ID: D.ID, Name: D.Name)) {
499 Main.codeDescription.emplace();
500 Main.codeDescription->href = std::move(*URI);
501 }
502 switch (D.Source) {
503 case Diag::Clang:
504 Main.source = "clang";
505 break;
506 case Diag::ClangTidy:
507 Main.source = "clang-tidy";
508 break;
509 case Diag::Clangd:
510 Main.source = "clangd";
511 break;
512 case Diag::ClangdConfig:
513 Main.source = "clangd-config";
514 break;
515 case Diag::Unknown:
516 break;
517 }
518 if (Opts.SendDiagnosticCategory && !D.Category.empty())
519 Main.category = D.Category;
520
521 Main.message = mainMessage(D, Opts);
522 if (Opts.EmitRelatedLocations) {
523 Main.relatedInformation.emplace();
524 for (auto &Note : D.Notes) {
525 if (!Note.AbsFile) {
526 vlog("Dropping note from unknown file: {0}", Note);
527 continue;
528 }
529 DiagnosticRelatedInformation RelInfo;
530 RelInfo.location.range = Note.Range;
531 RelInfo.location.uri =
532 URIForFile::canonicalize(*Note.AbsFile, File.file());
533 RelInfo.message = noteMessage(D, Note, Opts);
534 Main.relatedInformation->push_back(std::move(RelInfo));
535 }
536 }
537 Main.tags = D.Tags;
538 // FIXME: Get rid of the copies here by taking in a mutable clangd::Diag.
539 for (auto &Entry : D.OpaqueData)
540 Main.data.insert({Entry.first, Entry.second});
541 OutFn(std::move(Main), D.Fixes);
542
543 // If we didn't emit the notes as relatedLocations, emit separate diagnostics
544 // so the user can find the locations easily.
545 if (!Opts.EmitRelatedLocations)
546 for (auto &Note : D.Notes) {
547 if (!Note.InsideMainFile)
548 continue;
549 clangd::Diagnostic Res;
550 Res.severity = getSeverity(Note.Severity);
551 Res.range = Note.Range;
552 Res.message = noteMessage(D, Note, Opts);
553 OutFn(std::move(Res), llvm::ArrayRef<Fix>());
554 }
555}
556
557int getSeverity(DiagnosticsEngine::Level L) {
558 switch (L) {
559 case DiagnosticsEngine::Remark:
560 return 4;
561 case DiagnosticsEngine::Note:
562 return 3;
563 case DiagnosticsEngine::Warning:
564 return 2;
565 case DiagnosticsEngine::Fatal:
566 case DiagnosticsEngine::Error:
567 return 1;
568 case DiagnosticsEngine::Ignored:
569 return 0;
570 }
571 llvm_unreachable("Unknown diagnostic level!");
572}
573
574std::vector<Diag> StoreDiags::take(const clang::tidy::ClangTidyContext *Tidy) {
575 // Do not forget to emit a pending diagnostic if there is one.
576 flushLastDiag();
577
578 // Fill in name/source now that we have all the context needed to map them.
579 for (auto &Diag : Output) {
580 if (const char *ClangDiag = getDiagnosticCode(Diag.ID)) {
581 // Warnings controlled by -Wfoo are better recognized by that name.
582 StringRef Warning = DiagnosticIDs::getWarningOptionForDiag(Diag.ID);
583 if (!Warning.empty()) {
584 Diag.Name = ("-W" + Warning).str();
585 } else {
586 StringRef Name(ClangDiag);
587 // Almost always an error, with a name like err_enum_class_reference.
588 // Drop the err_ prefix for brevity.
589 Name.consume_front("err_");
590 Diag.Name = std::string(Name);
591 }
592 Diag.Source = Diag::Clang;
593 } else if (Tidy != nullptr) {
594 std::string TidyDiag = Tidy->getCheckName(Diag.ID);
595 if (!TidyDiag.empty()) {
596 Diag.Name = std::move(TidyDiag);
597 Diag.Source = Diag::ClangTidy;
598 // clang-tidy bakes the name into diagnostic messages. Strip it out.
599 // It would be much nicer to make clang-tidy not do this.
600 auto CleanMessage = [&](std::string &Msg) {
601 StringRef Rest(Msg);
602 if (Rest.consume_back("]") && Rest.consume_back(Diag.Name) &&
603 Rest.consume_back(" ["))
604 Msg.resize(Rest.size());
605 };
606 CleanMessage(Diag.Message);
607 for (auto &Note : Diag.Notes)
608 CleanMessage(Note.Message);
609 for (auto &Fix : Diag.Fixes)
610 CleanMessage(Fix.Message);
611 }
612 }
613 setTags(Diag);
614 }
615 // Deduplicate clang-tidy diagnostics -- some clang-tidy checks may emit
616 // duplicated messages due to various reasons (e.g. the check doesn't handle
617 // template instantiations well; clang-tidy alias checks).
618 std::set<std::pair<Range, std::string>> SeenDiags;
619 llvm::erase_if(Output, [&](const Diag &D) {
620 return !SeenDiags.emplace(D.Range, D.Message).second;
621 });
622 return std::move(Output);
623}
624
625void StoreDiags::BeginSourceFile(const LangOptions &Opts,
626 const Preprocessor *PP) {
627 LangOpts = Opts;
628 if (PP) {
629 OrigSrcMgr = &PP->getSourceManager();
630 }
631}
632
633void StoreDiags::EndSourceFile() {
634 flushLastDiag();
635 LangOpts = std::nullopt;
636 OrigSrcMgr = nullptr;
637}
638
639/// Sanitizes a piece for presenting it in a synthesized fix message. Ensures
640/// the result is not too large and does not contain newlines.
641static void writeCodeToFixMessage(llvm::raw_ostream &OS, llvm::StringRef Code) {
642 constexpr unsigned MaxLen = 50;
643 if (Code == "\n") {
644 OS << "\\n";
645 return;
646 }
647 // Only show the first line if there are many.
648 llvm::StringRef R = Code.split('\n').first;
649 // Shorten the message if it's too long.
650 R = R.take_front(N: MaxLen);
651
652 OS << R;
653 if (R.size() != Code.size())
654 OS << "…";
655}
656
657/// Fills \p D with all information, except the location-related bits.
658/// Also note that ID and Name are not part of clangd::DiagBase and should be
659/// set elsewhere.
660static void fillNonLocationData(DiagnosticsEngine::Level DiagLevel,
661 const clang::Diagnostic &Info,
662 clangd::DiagBase &D) {
663 llvm::SmallString<64> Message;
664 Info.FormatDiagnostic(Message);
665
666 D.Message = std::string(Message);
667 D.Severity = DiagLevel;
668 D.Category = DiagnosticIDs::getCategoryNameFromID(
669 CategoryID: DiagnosticIDs::getCategoryNumberForDiag(DiagID: Info.getID()))
670 .str();
671}
672
673void StoreDiags::HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
674 const clang::Diagnostic &Info) {
675 // If the diagnostic was generated for a different SourceManager, skip it.
676 // This happens when a module is imported and needs to be implicitly built.
677 // The compilation of that module will use the same StoreDiags, but different
678 // SourceManager.
679 if (OrigSrcMgr && Info.hasSourceManager() &&
680 OrigSrcMgr != &Info.getSourceManager()) {
681 IgnoreDiagnostics::log(DiagLevel, Info);
682 return;
683 }
684
685 DiagnosticConsumer::HandleDiagnostic(DiagLevel, Info);
686 bool OriginallyError =
687 Info.getDiags()->getDiagnosticIDs()->isDefaultMappingAsError(
688 DiagID: Info.getID());
689
690 if (Info.getLocation().isInvalid()) {
691 // Handle diagnostics coming from command-line arguments. The source manager
692 // is *not* available at this point, so we cannot use it.
693 if (!OriginallyError) {
694 IgnoreDiagnostics::log(DiagLevel, Info);
695 return; // non-errors add too much noise, do not show them.
696 }
697
698 flushLastDiag();
699
700 LastDiag = Diag();
701 LastDiagLoc.reset();
702 LastDiagOriginallyError = OriginallyError;
703 LastDiag->ID = Info.getID();
704 fillNonLocationData(DiagLevel, Info, D&: *LastDiag);
705 LastDiag->InsideMainFile = true;
706 // Put it at the start of the main file, for a lack of a better place.
707 LastDiag->Range.start = Position{.line: 0, .character: 0};
708 LastDiag->Range.end = Position{.line: 0, .character: 0};
709 return;
710 }
711
712 if (!LangOpts || !Info.hasSourceManager()) {
713 IgnoreDiagnostics::log(DiagLevel, Info);
714 return;
715 }
716
717 SourceManager &SM = Info.getSourceManager();
718
719 auto FillDiagBase = [&](DiagBase &D) {
720 fillNonLocationData(DiagLevel, Info, D);
721
722 SourceLocation PatchLoc =
723 translatePreamblePatchLocation(Loc: Info.getLocation(), SM);
724 D.InsideMainFile = isInsideMainFile(Loc: PatchLoc, SM);
725 if (auto DRange = diagnosticRange(D: Info, L: *LangOpts))
726 D.Range = *DRange;
727 else
728 D.Severity = DiagnosticsEngine::Ignored;
729 auto FID = SM.getFileID(SpellingLoc: Info.getLocation());
730 if (const auto FE = SM.getFileEntryRefForID(FID)) {
731 D.File = FE->getName().str();
732 D.AbsFile = getCanonicalPath(F: *FE, FileMgr&: SM.getFileManager());
733 }
734 D.ID = Info.getID();
735 return D;
736 };
737
738 auto AddFix = [&](bool SyntheticMessage) -> bool {
739 assert(!Info.getFixItHints().empty() &&
740 "diagnostic does not have attached fix-its");
741 // No point in generating fixes, if the diagnostic is for a different file.
742 if (!LastDiag->InsideMainFile)
743 return false;
744 // Copy as we may modify the ranges.
745 auto FixIts = Info.getFixItHints().vec();
746 llvm::SmallVector<TextEdit, 1> Edits;
747 for (auto &FixIt : FixIts) {
748 // Allow fixits within a single macro-arg expansion to be applied.
749 // This can be incorrect if the argument is expanded multiple times in
750 // different contexts. Hopefully this is rare!
751 if (FixIt.RemoveRange.getBegin().isMacroID() &&
752 FixIt.RemoveRange.getEnd().isMacroID() &&
753 SM.getFileID(FixIt.RemoveRange.getBegin()) ==
754 SM.getFileID(FixIt.RemoveRange.getEnd())) {
755 FixIt.RemoveRange = CharSourceRange(
756 {SM.getTopMacroCallerLoc(FixIt.RemoveRange.getBegin()),
757 SM.getTopMacroCallerLoc(FixIt.RemoveRange.getEnd())},
758 FixIt.RemoveRange.isTokenRange());
759 }
760 // Otherwise, follow clang's behavior: no fixits in macros.
761 if (FixIt.RemoveRange.getBegin().isMacroID() ||
762 FixIt.RemoveRange.getEnd().isMacroID())
763 return false;
764 if (!isInsideMainFile(FixIt.RemoveRange.getBegin(), SM))
765 return false;
766 Edits.push_back(toTextEdit(FixIt, SM, *LangOpts));
767 }
768
769 llvm::SmallString<64> Message;
770 // If requested and possible, create a message like "change 'foo' to 'bar'".
771 if (SyntheticMessage && FixIts.size() == 1) {
772 const auto &FixIt = FixIts.front();
773 bool Invalid = false;
774 llvm::StringRef Remove =
775 Lexer::getSourceText(Range: FixIt.RemoveRange, SM, LangOpts: *LangOpts, Invalid: &Invalid);
776 llvm::StringRef Insert = FixIt.CodeToInsert;
777 if (!Invalid) {
778 llvm::raw_svector_ostream M(Message);
779 if (!Remove.empty() && !Insert.empty()) {
780 M << "change '";
781 writeCodeToFixMessage(OS&: M, Code: Remove);
782 M << "' to '";
783 writeCodeToFixMessage(OS&: M, Code: Insert);
784 M << "'";
785 } else if (!Remove.empty()) {
786 M << "remove '";
787 writeCodeToFixMessage(OS&: M, Code: Remove);
788 M << "'";
789 } else if (!Insert.empty()) {
790 M << "insert '";
791 writeCodeToFixMessage(OS&: M, Code: Insert);
792 M << "'";
793 }
794 // Don't allow source code to inject newlines into diagnostics.
795 std::replace(Message.begin(), Message.end(), '\n', ' ');
796 }
797 }
798 if (Message.empty()) // either !SyntheticMessage, or we failed to make one.
799 Info.FormatDiagnostic(Message);
800 LastDiag->Fixes.push_back(
801 x: Fix{std::string(Message), std::move(Edits), {}});
802 return true;
803 };
804
805 if (!isNote(L: DiagLevel)) {
806 // Handle the new main diagnostic.
807 flushLastDiag();
808
809 LastDiag = Diag();
810 // FIXME: Merge with feature modules.
811 if (Adjuster)
812 DiagLevel = Adjuster(DiagLevel, Info);
813
814 FillDiagBase(*LastDiag);
815 if (isExcluded(DiagID: LastDiag->ID))
816 LastDiag->Severity = DiagnosticsEngine::Ignored;
817 if (DiagCB)
818 DiagCB(Info, *LastDiag);
819 // Don't bother filling in the rest if diag is going to be dropped.
820 if (LastDiag->Severity == DiagnosticsEngine::Ignored)
821 return;
822
823 LastDiagLoc.emplace(Info.getLocation(), Info.getSourceManager());
824 LastDiagOriginallyError = OriginallyError;
825 if (!Info.getFixItHints().empty())
826 AddFix(true /* try to invent a message instead of repeating the diag */);
827 if (Fixer) {
828 auto ExtraFixes = Fixer(LastDiag->Severity, Info);
829 LastDiag->Fixes.insert(LastDiag->Fixes.end(), ExtraFixes.begin(),
830 ExtraFixes.end());
831 }
832 } else {
833 // Handle a note to an existing diagnostic.
834 if (!LastDiag) {
835 assert(false && "Adding a note without main diagnostic");
836 IgnoreDiagnostics::log(DiagLevel, Info);
837 return;
838 }
839
840 // If a diagnostic was suppressed due to the suppression filter,
841 // also suppress notes associated with it.
842 if (LastDiag->Severity == DiagnosticsEngine::Ignored)
843 return;
844
845 // Give include-fixer a chance to replace a note with a fix.
846 if (Fixer) {
847 auto ReplacementFixes = Fixer(LastDiag->Severity, Info);
848 if (!ReplacementFixes.empty()) {
849 assert(Info.getNumFixItHints() == 0 &&
850 "Include-fixer replaced a note with clang fix-its attached!");
851 LastDiag->Fixes.insert(LastDiag->Fixes.end(), ReplacementFixes.begin(),
852 ReplacementFixes.end());
853 return;
854 }
855 }
856
857 if (!Info.getFixItHints().empty()) {
858 // A clang note with fix-it is not a separate diagnostic in clangd. We
859 // attach it as a Fix to the main diagnostic instead.
860 if (!AddFix(false /* use the note as the message */))
861 IgnoreDiagnostics::log(DiagLevel, Info);
862 } else {
863 // A clang note without fix-its corresponds to clangd::Note.
864 Note N;
865 FillDiagBase(N);
866
867 LastDiag->Notes.push_back(std::move(N));
868 }
869 }
870}
871
872void StoreDiags::flushLastDiag() {
873 if (!LastDiag)
874 return;
875 auto Finish = llvm::make_scope_exit([&, NDiags(Output.size())] {
876 if (Output.size() == NDiags) // No new diag emitted.
877 vlog("Dropped diagnostic: {0}: {1}", LastDiag->File, LastDiag->Message);
878 LastDiag.reset();
879 });
880
881 if (LastDiag->Severity == DiagnosticsEngine::Ignored)
882 return;
883 // Move errors that occur from headers into main file.
884 if (!LastDiag->InsideMainFile && LastDiagLoc && LastDiagOriginallyError) {
885 if (tryMoveToMainFile(D&: *LastDiag, DiagLoc: *LastDiagLoc)) {
886 // Suppress multiple errors from the same inclusion.
887 if (!IncludedErrorLocations
888 .insert({LastDiag->Range.start.line,
889 LastDiag->Range.start.character})
890 .second)
891 return;
892 }
893 }
894 if (!mentionsMainFile(D: *LastDiag))
895 return;
896 Output.push_back(std::move(*LastDiag));
897}
898
899bool isBuiltinDiagnosticSuppressed(unsigned ID,
900 const llvm::StringSet<> &Suppress,
901 const LangOptions &LangOpts) {
902 // Don't complain about header-only stuff in mainfiles if it's a header.
903 // FIXME: would be cleaner to suppress in clang, once we decide whether the
904 // behavior should be to silently-ignore or respect the pragma.
905 if (ID == diag::pp_pragma_sysheader_in_main_file && LangOpts.IsHeaderFile)
906 return true;
907
908 if (const char *CodePtr = getDiagnosticCode(ID)) {
909 if (Suppress.contains(normalizeSuppressedCode(CodePtr)))
910 return true;
911 }
912 StringRef Warning = DiagnosticIDs::getWarningOptionForDiag(DiagID: ID);
913 if (!Warning.empty() && Suppress.contains(Warning))
914 return true;
915 return false;
916}
917
918llvm::StringRef normalizeSuppressedCode(llvm::StringRef Code) {
919 Code.consume_front(Prefix: "err_");
920 Code.consume_front(Prefix: "-W");
921 return Code;
922}
923
924std::optional<std::string> getDiagnosticDocURI(Diag::DiagSource Source,
925 unsigned ID,
926 llvm::StringRef Name) {
927 switch (Source) {
928 case Diag::Unknown:
929 break;
930 case Diag::Clang:
931 // There is a page listing many warning flags, but it provides too little
932 // information to be worth linking.
933 // https://clang.llvm.org/docs/DiagnosticsReference.html
934 break;
935 case Diag::ClangTidy: {
936 StringRef Module, Check;
937 // This won't correctly get the module for clang-analyzer checks, but as we
938 // don't link in the analyzer that shouldn't be an issue.
939 // This would also need updating if anyone decides to create a module with a
940 // '-' in the name.
941 std::tie(Module, Check) = Name.split('-');
942 if (Module.empty() || Check.empty())
943 return std::nullopt;
944 return ("https://clang.llvm.org/extra/clang-tidy/checks/" + Module + "/" +
945 Check + ".html")
946 .str();
947 }
948 case Diag::Clangd:
949 if (Name == "unused-includes" || Name == "missing-includes")
950 return {"https://clangd.llvm.org/guides/include-cleaner"};
951 break;
952 case Diag::ClangdConfig:
953 // FIXME: we should link to https://clangd.llvm.org/config
954 // However we have no diagnostic codes, which the link should describe!
955 break;
956 }
957 return std::nullopt;
958}
959
960} // namespace clangd
961} // namespace clang
962

source code of clang-tools-extra/clangd/Diagnostics.cpp