1//===--- ParsedAST.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 "ParsedAST.h"
10#include "../clang-tidy/ClangTidyCheck.h"
11#include "../clang-tidy/ClangTidyDiagnosticConsumer.h"
12#include "../clang-tidy/ClangTidyModule.h"
13#include "../clang-tidy/ClangTidyModuleRegistry.h"
14#include "../clang-tidy/ClangTidyOptions.h"
15#include "AST.h"
16#include "CollectMacros.h"
17#include "Compiler.h"
18#include "Config.h"
19#include "Diagnostics.h"
20#include "Feature.h"
21#include "FeatureModule.h"
22#include "Headers.h"
23#include "HeuristicResolver.h"
24#include "IncludeCleaner.h"
25#include "IncludeFixer.h"
26#include "Preamble.h"
27#include "SourceCode.h"
28#include "TidyProvider.h"
29#include "clang-include-cleaner/Record.h"
30#include "index/Symbol.h"
31#include "support/Logger.h"
32#include "support/Path.h"
33#include "support/Trace.h"
34#include "clang/AST/ASTContext.h"
35#include "clang/AST/Decl.h"
36#include "clang/AST/DeclGroup.h"
37#include "clang/AST/ExternalASTSource.h"
38#include "clang/ASTMatchers/ASTMatchFinder.h"
39#include "clang/Basic/Diagnostic.h"
40#include "clang/Basic/DiagnosticIDs.h"
41#include "clang/Basic/DiagnosticSema.h"
42#include "clang/Basic/FileEntry.h"
43#include "clang/Basic/LLVM.h"
44#include "clang/Basic/LangOptions.h"
45#include "clang/Basic/SourceLocation.h"
46#include "clang/Basic/SourceManager.h"
47#include "clang/Basic/TokenKinds.h"
48#include "clang/Frontend/CompilerInstance.h"
49#include "clang/Frontend/CompilerInvocation.h"
50#include "clang/Frontend/FrontendActions.h"
51#include "clang/Frontend/FrontendOptions.h"
52#include "clang/Frontend/PrecompiledPreamble.h"
53#include "clang/Lex/Lexer.h"
54#include "clang/Lex/PPCallbacks.h"
55#include "clang/Lex/Preprocessor.h"
56#include "clang/Serialization/ASTWriter.h"
57#include "clang/Tooling/CompilationDatabase.h"
58#include "clang/Tooling/Core/Diagnostic.h"
59#include "clang/Tooling/Syntax/Tokens.h"
60#include "llvm/ADT/ArrayRef.h"
61#include "llvm/ADT/DenseMap.h"
62#include "llvm/ADT/DenseSet.h"
63#include "llvm/ADT/STLExtras.h"
64#include "llvm/ADT/STLFunctionalExtras.h"
65#include "llvm/ADT/SmallVector.h"
66#include "llvm/ADT/StringRef.h"
67#include "llvm/Support/Error.h"
68#include "llvm/Support/MemoryBuffer.h"
69#include <cassert>
70#include <cstddef>
71#include <iterator>
72#include <memory>
73#include <optional>
74#include <string>
75#include <tuple>
76#include <utility>
77#include <vector>
78
79// Force the linker to link in Clang-tidy modules.
80// clangd doesn't support the static analyzer.
81#if CLANGD_TIDY_CHECKS
82#define CLANG_TIDY_DISABLE_STATIC_ANALYZER_CHECKS
83#include "../clang-tidy/ClangTidyForceLinker.h"
84#endif
85
86namespace clang {
87namespace clangd {
88namespace {
89
90template <class T> std::size_t getUsedBytes(const std::vector<T> &Vec) {
91 return Vec.capacity() * sizeof(T);
92}
93
94class DeclTrackingASTConsumer : public ASTConsumer {
95public:
96 DeclTrackingASTConsumer(std::vector<Decl *> &TopLevelDecls)
97 : TopLevelDecls(TopLevelDecls) {}
98
99 bool HandleTopLevelDecl(DeclGroupRef DG) override {
100 for (Decl *D : DG) {
101 auto &SM = D->getASTContext().getSourceManager();
102 if (!isInsideMainFile(Loc: D->getLocation(), SM))
103 continue;
104 if (const NamedDecl *ND = dyn_cast<NamedDecl>(Val: D))
105 if (isImplicitTemplateInstantiation(D: ND))
106 continue;
107
108 // ObjCMethodDecl are not actually top-level decls.
109 if (isa<ObjCMethodDecl>(Val: D))
110 continue;
111
112 TopLevelDecls.push_back(x: D);
113 }
114 return true;
115 }
116
117private:
118 std::vector<Decl *> &TopLevelDecls;
119};
120
121class ClangdFrontendAction : public SyntaxOnlyAction {
122public:
123 std::vector<Decl *> takeTopLevelDecls() { return std::move(TopLevelDecls); }
124
125protected:
126 std::unique_ptr<ASTConsumer>
127 CreateASTConsumer(CompilerInstance &CI, llvm::StringRef InFile) override {
128 return std::make_unique<DeclTrackingASTConsumer>(/*ref*/ args&: TopLevelDecls);
129 }
130
131private:
132 std::vector<Decl *> TopLevelDecls;
133};
134
135// When using a preamble, only preprocessor events outside its bounds are seen.
136// This is almost what we want: replaying transitive preprocessing wastes time.
137// However this confuses clang-tidy checks: they don't see any #includes!
138// So we replay the *non-transitive* #includes that appear in the main-file.
139// It would be nice to replay other events (macro definitions, ifdefs etc) but
140// this addresses the most common cases fairly cheaply.
141class ReplayPreamble : private PPCallbacks {
142public:
143 // Attach preprocessor hooks such that preamble events will be injected at
144 // the appropriate time.
145 // Events will be delivered to the *currently registered* PP callbacks.
146 static void attach(std::vector<Inclusion> Includes, CompilerInstance &Clang,
147 const PreambleBounds &PB) {
148 auto &PP = Clang.getPreprocessor();
149 auto *ExistingCallbacks = PP.getPPCallbacks();
150 // No need to replay events if nobody is listening.
151 if (!ExistingCallbacks)
152 return;
153 PP.addPPCallbacks(C: std::unique_ptr<PPCallbacks>(new ReplayPreamble(
154 std::move(Includes), ExistingCallbacks, Clang.getSourceManager(), PP,
155 Clang.getLangOpts(), PB)));
156 // We're relying on the fact that addPPCallbacks keeps the old PPCallbacks
157 // around, creating a chaining wrapper. Guard against other implementations.
158 assert(PP.getPPCallbacks() != ExistingCallbacks &&
159 "Expected chaining implementation");
160 }
161
162private:
163 ReplayPreamble(std::vector<Inclusion> Includes, PPCallbacks *Delegate,
164 const SourceManager &SM, Preprocessor &PP,
165 const LangOptions &LangOpts, const PreambleBounds &PB)
166 : Includes(std::move(Includes)), Delegate(Delegate), SM(SM), PP(PP) {
167 // Only tokenize the preamble section of the main file, as we are not
168 // interested in the rest of the tokens.
169 MainFileTokens = syntax::tokenize(
170 FR: syntax::FileRange(SM.getMainFileID(), 0, PB.Size), SM, LO: LangOpts);
171 }
172
173 // In a normal compile, the preamble traverses the following structure:
174 //
175 // mainfile.cpp
176 // <built-in>
177 // ... macro definitions like __cplusplus ...
178 // <command-line>
179 // ... macro definitions for args like -Dfoo=bar ...
180 // "header1.h"
181 // ... header file contents ...
182 // "header2.h"
183 // ... header file contents ...
184 // ... main file contents ...
185 //
186 // When using a preamble, the "header1" and "header2" subtrees get skipped.
187 // We insert them right after the built-in header, which still appears.
188 void FileChanged(SourceLocation Loc, FileChangeReason Reason,
189 SrcMgr::CharacteristicKind Kind, FileID PrevFID) override {
190 // It'd be nice if there was a better way to identify built-in headers...
191 if (Reason == FileChangeReason::ExitFile &&
192 SM.getBufferOrFake(FID: PrevFID).getBufferIdentifier() == "<built-in>")
193 replay();
194 }
195
196 void replay() {
197 for (const auto &Inc : Includes) {
198 OptionalFileEntryRef File;
199 if (Inc.Resolved != "")
200 File = expectedToOptional(E: SM.getFileManager().getFileRef(Filename: Inc.Resolved));
201
202 // Re-lex the #include directive to find its interesting parts.
203 auto HashLoc = SM.getComposedLoc(FID: SM.getMainFileID(), Offset: Inc.HashOffset);
204 auto HashTok = llvm::partition_point(Range&: MainFileTokens,
205 P: [&HashLoc](const syntax::Token &T) {
206 return T.location() < HashLoc;
207 });
208 assert(HashTok != MainFileTokens.end() && HashTok->kind() == tok::hash);
209
210 auto IncludeTok = std::next(x: HashTok);
211 assert(IncludeTok != MainFileTokens.end());
212
213 auto FileTok = std::next(x: IncludeTok);
214 assert(FileTok != MainFileTokens.end());
215
216 // Create a fake import/include token, none of the callers seem to care
217 // about clang::Token::Flags.
218 Token SynthesizedIncludeTok;
219 SynthesizedIncludeTok.startToken();
220 SynthesizedIncludeTok.setLocation(IncludeTok->location());
221 SynthesizedIncludeTok.setLength(IncludeTok->length());
222 SynthesizedIncludeTok.setKind(tok::raw_identifier);
223 SynthesizedIncludeTok.setRawIdentifierData(IncludeTok->text(SM).data());
224 PP.LookUpIdentifierInfo(Identifier&: SynthesizedIncludeTok);
225
226 // Same here, create a fake one for Filename, including angles or quotes.
227 Token SynthesizedFilenameTok;
228 SynthesizedFilenameTok.startToken();
229 SynthesizedFilenameTok.setLocation(FileTok->location());
230 // Note that we can't make use of FileTok->length/text in here as in the
231 // case of angled includes this will contain tok::less instead of
232 // filename. Whereas Inc.Written contains the full header name including
233 // quotes/angles.
234 SynthesizedFilenameTok.setLength(Inc.Written.length());
235 SynthesizedFilenameTok.setKind(tok::header_name);
236 SynthesizedFilenameTok.setLiteralData(Inc.Written.data());
237
238 llvm::StringRef WrittenFilename =
239 llvm::StringRef(Inc.Written).drop_front().drop_back();
240 Delegate->InclusionDirective(
241 HashLoc: HashTok->location(), IncludeTok: SynthesizedIncludeTok, FileName: WrittenFilename,
242 IsAngled: Inc.Written.front() == '<',
243 FilenameRange: syntax::FileRange(SM, SynthesizedFilenameTok.getLocation(),
244 SynthesizedFilenameTok.getEndLoc())
245 .toCharRange(SM),
246 File, SearchPath: "SearchPath", RelativePath: "RelPath",
247 /*SuggestedModule=*/nullptr, /*ModuleImported=*/false, FileType: Inc.FileKind);
248 if (File)
249 Delegate->FileSkipped(SkippedFile: *File, FilenameTok: SynthesizedFilenameTok, FileType: Inc.FileKind);
250 }
251 }
252
253 const std::vector<Inclusion> Includes;
254 PPCallbacks *Delegate;
255 const SourceManager &SM;
256 Preprocessor &PP;
257 std::vector<syntax::Token> MainFileTokens;
258};
259
260// Filter for clang diagnostics groups enabled by CTOptions.Checks.
261//
262// These are check names like clang-diagnostics-unused.
263// Note that unlike -Wunused, clang-diagnostics-unused does not imply
264// subcategories like clang-diagnostics-unused-function.
265//
266// This is used to determine which diagnostics can be enabled by ExtraArgs in
267// the clang-tidy configuration.
268class TidyDiagnosticGroups {
269 // Whether all diagnostic groups are enabled by default.
270 // True if we've seen clang-diagnostic-*.
271 bool Default = false;
272 // Set of diag::Group whose enablement != Default.
273 // If Default is false, this is foo where we've seen clang-diagnostic-foo.
274 llvm::DenseSet<unsigned> Exceptions;
275
276public:
277 TidyDiagnosticGroups(llvm::StringRef Checks) {
278 constexpr llvm::StringLiteral CDPrefix = "clang-diagnostic-";
279
280 llvm::StringRef Check;
281 while (!Checks.empty()) {
282 std::tie(args&: Check, args&: Checks) = Checks.split(Separator: ',');
283 if (Check.empty())
284 continue;
285
286 bool Enable = !Check.consume_front(Prefix: "-");
287 bool Glob = Check.consume_back(Suffix: "*");
288 if (Glob) {
289 // Is this clang-diagnostic-*, or *, or so?
290 // (We ignore all other types of globs).
291 if (CDPrefix.starts_with(Prefix: Check)) {
292 Default = Enable;
293 Exceptions.clear();
294 }
295 continue;
296 }
297
298 // In "*,clang-diagnostic-foo", the latter is a no-op.
299 if (Default == Enable)
300 continue;
301 // The only non-glob entries we care about are clang-diagnostic-foo.
302 if (!Check.consume_front(Prefix: CDPrefix))
303 continue;
304
305 if (auto Group = DiagnosticIDs::getGroupForWarningOption(Check))
306 Exceptions.insert(V: static_cast<unsigned>(*Group));
307 }
308 }
309
310 bool operator()(diag::Group GroupID) const {
311 return Exceptions.contains(V: static_cast<unsigned>(GroupID)) ? !Default
312 : Default;
313 }
314};
315
316// Find -W<group> and -Wno-<group> options in ExtraArgs and apply them to Diags.
317//
318// This is used to handle ExtraArgs in clang-tidy configuration.
319// We don't use clang's standard handling of this as we want slightly different
320// behavior (e.g. we want to exclude these from -Wno-error).
321void applyWarningOptions(llvm::ArrayRef<std::string> ExtraArgs,
322 llvm::function_ref<bool(diag::Group)> EnabledGroups,
323 DiagnosticsEngine &Diags) {
324 for (llvm::StringRef Group : ExtraArgs) {
325 // Only handle args that are of the form -W[no-]<group>.
326 // Other flags are possible but rare and deliberately out of scope.
327 llvm::SmallVector<diag::kind> Members;
328 if (!Group.consume_front(Prefix: "-W") || Group.empty())
329 continue;
330 bool Enable = !Group.consume_front(Prefix: "no-");
331 if (Diags.getDiagnosticIDs()->getDiagnosticsInGroup(
332 Flavor: diag::Flavor::WarningOrError, Group, Diags&: Members))
333 continue;
334
335 // Upgrade (or downgrade) the severity of each diagnostic in the group.
336 // If -Werror is on, newly added warnings will be treated as errors.
337 // We don't want this, so keep track of them to fix afterwards.
338 bool NeedsWerrorExclusion = false;
339 for (diag::kind ID : Members) {
340 if (Enable) {
341 if (Diags.getDiagnosticLevel(DiagID: ID, Loc: SourceLocation()) <
342 DiagnosticsEngine::Warning) {
343 auto Group = DiagnosticIDs::getGroupForDiag(DiagID: ID);
344 if (!Group || !EnabledGroups(*Group))
345 continue;
346 Diags.setSeverity(Diag: ID, Map: diag::Severity::Warning, Loc: SourceLocation());
347 if (Diags.getWarningsAsErrors())
348 NeedsWerrorExclusion = true;
349 }
350 } else {
351 Diags.setSeverity(Diag: ID, Map: diag::Severity::Ignored, Loc: SourceLocation());
352 }
353 }
354 if (NeedsWerrorExclusion) {
355 // FIXME: there's no API to suppress -Werror for single diagnostics.
356 // In some cases with sub-groups, we may end up erroneously
357 // downgrading diagnostics that were -Werror in the compile command.
358 Diags.setDiagnosticGroupWarningAsError(Group, Enabled: false);
359 }
360 }
361}
362
363std::vector<Diag> getIncludeCleanerDiags(ParsedAST &AST, llvm::StringRef Code) {
364 auto &Cfg = Config::current();
365 if (Cfg.Diagnostics.SuppressAll)
366 return {};
367 bool SuppressMissing =
368 Cfg.Diagnostics.Suppress.contains(key: "missing-includes") ||
369 Cfg.Diagnostics.MissingIncludes == Config::IncludesPolicy::None;
370 bool SuppressUnused =
371 Cfg.Diagnostics.Suppress.contains(key: "unused-includes") ||
372 Cfg.Diagnostics.UnusedIncludes == Config::IncludesPolicy::None;
373 if (SuppressMissing && SuppressUnused)
374 return {};
375 auto Findings = computeIncludeCleanerFindings(AST);
376 if (SuppressMissing)
377 Findings.MissingIncludes.clear();
378 if (SuppressUnused)
379 Findings.UnusedIncludes.clear();
380 return issueIncludeCleanerDiagnostics(AST, Code, Findings,
381 IgnoreHeader: Cfg.Diagnostics.Includes.IgnoreHeader);
382}
383
384tidy::ClangTidyCheckFactories
385filterFastTidyChecks(const tidy::ClangTidyCheckFactories &All,
386 Config::FastCheckPolicy Policy) {
387 if (Policy == Config::FastCheckPolicy::None)
388 return All;
389 bool AllowUnknown = Policy == Config::FastCheckPolicy::Loose;
390 tidy::ClangTidyCheckFactories Fast;
391 for (const auto &Factory : All) {
392 if (isFastTidyCheck(Check: Factory.getKey()).value_or(u&: AllowUnknown))
393 Fast.registerCheckFactory(Name: Factory.first(), Factory: Factory.second);
394 }
395 return Fast;
396}
397
398} // namespace
399
400std::optional<ParsedAST>
401ParsedAST::build(llvm::StringRef Filename, const ParseInputs &Inputs,
402 std::unique_ptr<clang::CompilerInvocation> CI,
403 llvm::ArrayRef<Diag> CompilerInvocationDiags,
404 std::shared_ptr<const PreambleData> Preamble) {
405 trace::Span Tracer("BuildAST");
406 SPAN_ATTACH(Tracer, "File", Filename);
407 const Config &Cfg = Config::current();
408
409 auto VFS = Inputs.TFS->view(CWD: Inputs.CompileCommand.Directory);
410 if (Preamble && Preamble->StatCache)
411 VFS = Preamble->StatCache->getConsumingFS(FS: std::move(VFS));
412
413 assert(CI);
414
415 if (CI->getFrontendOpts().Inputs.size() > 0) {
416 auto Lang = CI->getFrontendOpts().Inputs[0].getKind().getLanguage();
417 if (Lang == Language::Asm || Lang == Language::LLVM_IR) {
418 elog(Fmt: "Clangd does not support assembly or IR source files");
419 return std::nullopt;
420 }
421 }
422
423 // Command-line parsing sets DisableFree to true by default, but we don't want
424 // to leak memory in clangd.
425 CI->getFrontendOpts().DisableFree = false;
426 const PrecompiledPreamble *PreamblePCH =
427 Preamble ? &Preamble->Preamble : nullptr;
428
429 // This is on-by-default in windows to allow parsing SDK headers, but it
430 // breaks many features. Disable it for the main-file (not preamble).
431 CI->getLangOpts().DelayedTemplateParsing = false;
432
433 std::vector<std::unique_ptr<FeatureModule::ASTListener>> ASTListeners;
434 if (Inputs.FeatureModules) {
435 for (auto &M : *Inputs.FeatureModules) {
436 if (auto Listener = M.astListeners())
437 ASTListeners.emplace_back(args: std::move(Listener));
438 }
439 }
440 StoreDiags ASTDiags;
441 ASTDiags.setDiagCallback(
442 [&ASTListeners](const clang::Diagnostic &D, clangd::Diag &Diag) {
443 for (const auto &L : ASTListeners)
444 L->sawDiagnostic(D, Diag);
445 });
446
447 std::optional<PreamblePatch> Patch;
448 // We might use an ignoring diagnostic consumer if they are going to be
449 // dropped later on to not pay for extra latency by processing them.
450 DiagnosticConsumer *DiagConsumer = &ASTDiags;
451 IgnoreDiagnostics DropDiags;
452 if (Preamble) {
453 Patch = PreamblePatch::createFullPatch(FileName: Filename, Modified: Inputs, Baseline: *Preamble);
454 Patch->apply(CI&: *CI);
455 }
456 auto Clang = prepareCompilerInstance(
457 std::move(CI), PreamblePCH,
458 MainFile: llvm::MemoryBuffer::getMemBufferCopy(InputData: Inputs.Contents, BufferName: Filename), VFS,
459 *DiagConsumer);
460 if (!Clang) {
461 // The last diagnostic contains information about the reason of this
462 // failure.
463 std::vector<Diag> Diags(ASTDiags.take());
464 elog(Fmt: "Failed to prepare a compiler instance: {0}",
465 Vals: !Diags.empty() ? static_cast<DiagBase &>(Diags.back()).Message
466 : "unknown error");
467 return std::nullopt;
468 }
469 tidy::ClangTidyOptions ClangTidyOpts;
470 {
471 trace::Span Tracer("ClangTidyOpts");
472 ClangTidyOpts = getTidyOptionsForFile(Provider: Inputs.ClangTidyProvider, Filename);
473 dlog("ClangTidy configuration for file {0}: {1}", Filename,
474 tidy::configurationAsText(ClangTidyOpts));
475
476 // If clang-tidy is configured to emit clang warnings, we should too.
477 //
478 // Such clang-tidy configuration consists of two parts:
479 // - ExtraArgs: ["-Wfoo"] causes clang to produce the warnings
480 // - Checks: "clang-diagnostic-foo" prevents clang-tidy filtering them out
481 //
482 // In clang-tidy, diagnostics are emitted if they pass both checks.
483 // When groups contain subgroups, -Wparent includes the child, but
484 // clang-diagnostic-parent does not.
485 //
486 // We *don't* want to change the compile command directly. This can have
487 // too many unexpected effects: breaking the command, interactions with
488 // -- and -Werror, etc. Besides, we've already parsed the command.
489 // Instead we parse the -W<group> flags and handle them directly.
490 //
491 // Similarly, we don't want to use Checks to filter clang diagnostics after
492 // they are generated, as this spreads clang-tidy emulation everywhere.
493 // Instead, we just use these to filter which extra diagnostics we enable.
494 auto &Diags = Clang->getDiagnostics();
495 TidyDiagnosticGroups TidyGroups(ClangTidyOpts.Checks ? *ClangTidyOpts.Checks
496 : llvm::StringRef());
497 if (ClangTidyOpts.ExtraArgsBefore)
498 applyWarningOptions(ExtraArgs: *ClangTidyOpts.ExtraArgsBefore, EnabledGroups: TidyGroups, Diags);
499 if (ClangTidyOpts.ExtraArgs)
500 applyWarningOptions(ExtraArgs: *ClangTidyOpts.ExtraArgs, EnabledGroups: TidyGroups, Diags);
501 }
502
503 auto Action = std::make_unique<ClangdFrontendAction>();
504 const FrontendInputFile &MainInput = Clang->getFrontendOpts().Inputs[0];
505 if (!Action->BeginSourceFile(CI&: *Clang, Input: MainInput)) {
506 log(Fmt: "BeginSourceFile() failed when building AST for {0}",
507 Vals: MainInput.getFile());
508 return std::nullopt;
509 }
510 // If we saw an include guard in the preamble section of the main file,
511 // mark the main-file as include-guarded.
512 // This information is part of the HeaderFileInfo but is not loaded from the
513 // preamble as the file's size is part of its identity and may have changed.
514 // (The rest of HeaderFileInfo is not relevant for our purposes).
515 if (Preamble && Preamble->MainIsIncludeGuarded) {
516 const SourceManager &SM = Clang->getSourceManager();
517 OptionalFileEntryRef MainFE = SM.getFileEntryRefForID(FID: SM.getMainFileID());
518 Clang->getPreprocessor().getHeaderSearchInfo().MarkFileIncludeOnce(File: *MainFE);
519 }
520
521 // Set up ClangTidy. Must happen after BeginSourceFile() so ASTContext exists.
522 // Clang-tidy has some limitations to ensure reasonable performance:
523 // - checks don't see all preprocessor events in the preamble
524 // - matchers run only over the main-file top-level decls (and can't see
525 // ancestors outside this scope).
526 // In practice almost all checks work well without modifications.
527 std::vector<std::unique_ptr<tidy::ClangTidyCheck>> CTChecks;
528 ast_matchers::MatchFinder CTFinder;
529 std::optional<tidy::ClangTidyContext> CTContext;
530 // Must outlive FixIncludes.
531 auto BuildDir = VFS->getCurrentWorkingDirectory();
532 std::optional<IncludeFixer> FixIncludes;
533 llvm::DenseMap<diag::kind, DiagnosticsEngine::Level> OverriddenSeverity;
534 // No need to run clang-tidy or IncludeFixerif we are not going to surface
535 // diagnostics.
536 {
537 trace::Span Tracer("ClangTidyInit");
538 static const auto *AllCTFactories = [] {
539 auto *CTFactories = new tidy::ClangTidyCheckFactories;
540 for (const auto &E : tidy::ClangTidyModuleRegistry::entries())
541 E.instantiate()->addCheckFactories(CheckFactories&: *CTFactories);
542 return CTFactories;
543 }();
544 tidy::ClangTidyCheckFactories FastFactories = filterFastTidyChecks(
545 All: *AllCTFactories, Policy: Cfg.Diagnostics.ClangTidy.FastCheckFilter);
546 CTContext.emplace(args: std::make_unique<tidy::DefaultOptionsProvider>(
547 args: tidy::ClangTidyGlobalOptions(), args&: ClangTidyOpts));
548 CTContext->setDiagnosticsEngine(&Clang->getDiagnostics());
549 CTContext->setASTContext(&Clang->getASTContext());
550 CTContext->setCurrentFile(Filename);
551 CTContext->setSelfContainedDiags(true);
552 CTChecks = FastFactories.createChecksForLanguage(Context: &*CTContext);
553 Preprocessor *PP = &Clang->getPreprocessor();
554 for (const auto &Check : CTChecks) {
555 Check->registerPPCallbacks(SM: Clang->getSourceManager(), PP, ModuleExpanderPP: PP);
556 Check->registerMatchers(Finder: &CTFinder);
557 }
558
559 // Clang only corrects typos for use of undeclared functions in C if that
560 // use is an error. Include fixer relies on typo correction, so pretend
561 // this is an error. (The actual typo correction is nice too).
562 // We restore the original severity in the level adjuster.
563 // FIXME: It would be better to have a real API for this, but what?
564 for (auto ID : {diag::ext_implicit_function_decl_c99,
565 diag::ext_implicit_lib_function_decl,
566 diag::ext_implicit_lib_function_decl_c99,
567 diag::warn_implicit_function_decl}) {
568 OverriddenSeverity.try_emplace(
569 ID, Clang->getDiagnostics().getDiagnosticLevel(ID, SourceLocation()));
570 Clang->getDiagnostics().setSeverity(ID, diag::Severity::Error,
571 SourceLocation());
572 }
573
574 ASTDiags.setLevelAdjuster([&](DiagnosticsEngine::Level DiagLevel,
575 const clang::Diagnostic &Info) {
576 if (Cfg.Diagnostics.SuppressAll ||
577 isBuiltinDiagnosticSuppressed(ID: Info.getID(), Suppressed: Cfg.Diagnostics.Suppress,
578 Clang->getLangOpts()))
579 return DiagnosticsEngine::Ignored;
580
581 auto It = OverriddenSeverity.find(Val: Info.getID());
582 if (It != OverriddenSeverity.end())
583 DiagLevel = It->second;
584
585 if (!CTChecks.empty()) {
586 std::string CheckName = CTContext->getCheckName(DiagnosticID: Info.getID());
587 bool IsClangTidyDiag = !CheckName.empty();
588 if (IsClangTidyDiag) {
589 if (Cfg.Diagnostics.Suppress.contains(key: CheckName))
590 return DiagnosticsEngine::Ignored;
591 // Check for suppression comment. Skip the check for diagnostics not
592 // in the main file, because we don't want that function to query the
593 // source buffer for preamble files. For the same reason, we ask
594 // shouldSuppressDiagnostic to avoid I/O.
595 // We let suppression comments take precedence over warning-as-error
596 // to match clang-tidy's behaviour.
597 bool IsInsideMainFile =
598 Info.hasSourceManager() &&
599 isInsideMainFile(Loc: Info.getLocation(), SM: Info.getSourceManager());
600 SmallVector<tooling::Diagnostic, 1> TidySuppressedErrors;
601 if (IsInsideMainFile && CTContext->shouldSuppressDiagnostic(
602 DiagLevel, Info, NoLintErrors&: TidySuppressedErrors,
603 /*AllowIO=*/false,
604 /*EnableNolintBlocks=*/EnableNoLintBlocks: true)) {
605 // FIXME: should we expose the suppression error (invalid use of
606 // NOLINT comments)?
607 return DiagnosticsEngine::Ignored;
608 }
609 if (!CTContext->getOptions().SystemHeaders.value_or(u: false) &&
610 Info.hasSourceManager() &&
611 Info.getSourceManager().isInSystemMacro(loc: Info.getLocation()))
612 return DiagnosticsEngine::Ignored;
613
614 // Check for warning-as-error.
615 if (DiagLevel == DiagnosticsEngine::Warning &&
616 CTContext->treatAsError(CheckName)) {
617 return DiagnosticsEngine::Error;
618 }
619 }
620 }
621 return DiagLevel;
622 });
623
624 // Add IncludeFixer which can recover diagnostics caused by missing includes
625 // (e.g. incomplete type) and attach include insertion fixes to diagnostics.
626 if (Inputs.Index && !BuildDir.getError()) {
627 auto Style =
628 getFormatStyleForFile(File: Filename, Content: Inputs.Contents, TFS: *Inputs.TFS);
629 auto Inserter = std::make_shared<IncludeInserter>(
630 args&: Filename, args: Inputs.Contents, args&: Style, args&: BuildDir.get(),
631 args: &Clang->getPreprocessor().getHeaderSearchInfo());
632 ArrayRef<Inclusion> MainFileIncludes;
633 if (Preamble) {
634 MainFileIncludes = Preamble->Includes.MainFileIncludes;
635 for (const auto &Inc : Preamble->Includes.MainFileIncludes)
636 Inserter->addExisting(Inc);
637 }
638 // FIXME: Consider piping through ASTSignals to fetch this to handle the
639 // case where a header file contains ObjC decls but no #imports.
640 Symbol::IncludeDirective Directive =
641 Inputs.Opts.ImportInsertions
642 ? preferredIncludeDirective(FileName: Filename, LangOpts: Clang->getLangOpts(),
643 MainFileIncludes, TopLevelDecls: {})
644 : Symbol::Include;
645 FixIncludes.emplace(args&: Filename, args&: Inserter, args: *Inputs.Index,
646 /*IndexRequestLimit=*/args: 5, args&: Directive);
647 ASTDiags.contributeFixes(Fixer: [&FixIncludes](DiagnosticsEngine::Level DiagLevl,
648 const clang::Diagnostic &Info) {
649 return FixIncludes->fix(DiagLevel: DiagLevl, Info);
650 });
651 Clang->setExternalSemaSource(FixIncludes->unresolvedNameRecorder());
652 }
653 }
654
655 IncludeStructure Includes;
656 include_cleaner::PragmaIncludes PI;
657 // If we are using a preamble, copy existing includes.
658 if (Preamble) {
659 Includes = Preamble->Includes;
660 Includes.MainFileIncludes = Patch->preambleIncludes();
661 // Replay the preamble includes so that clang-tidy checks can see them.
662 ReplayPreamble::attach(Includes: Patch->preambleIncludes(), Clang&: *Clang,
663 PB: Patch->modifiedBounds());
664 PI = *Preamble->Pragmas;
665 }
666 // Important: collectIncludeStructure is registered *after* ReplayPreamble!
667 // Otherwise we would collect the replayed includes again...
668 // (We can't *just* use the replayed includes, they don't have Resolved path).
669 Includes.collect(CI: *Clang);
670 // Same for pragma-includes, we're already inheriting preamble includes, so we
671 // should only receive callbacks for non-preamble mainfile includes.
672 PI.record(CI: *Clang);
673 // Copy over the macros in the preamble region of the main file, and combine
674 // with non-preamble macros below.
675 MainFileMacros Macros;
676 std::vector<PragmaMark> Marks;
677 if (Preamble) {
678 Macros = Patch->mainFileMacros();
679 Marks = Patch->marks();
680 }
681 auto &PP = Clang->getPreprocessor();
682 PP.addPPCallbacks(C: std::make_unique<CollectMainFileMacros>(args&: PP, args&: Macros));
683
684 PP.addPPCallbacks(
685 C: collectPragmaMarksCallback(Clang->getSourceManager(), Out&: Marks));
686
687 // FIXME: Attach a comment handler to take care of
688 // keep/export/no_include etc. IWYU pragmas.
689
690 // Collect tokens of the main file.
691 syntax::TokenCollector CollectTokens(PP);
692
693 // To remain consistent with preamble builds, these callbacks must be called
694 // exactly here, after preprocessor is initialized and BeginSourceFile() was
695 // called already.
696 for (const auto &L : ASTListeners)
697 L->beforeExecute(CI&: *Clang);
698
699 if (llvm::Error Err = Action->Execute())
700 log(Fmt: "Execute() failed when building AST for {0}: {1}", Vals: MainInput.getFile(),
701 Vals: toString(E: std::move(Err)));
702
703 // We have to consume the tokens before running clang-tidy to avoid collecting
704 // tokens from running the preprocessor inside the checks (only
705 // modernize-use-trailing-return-type does that today).
706 syntax::TokenBuffer Tokens = std::move(CollectTokens).consume();
707 // Makes SelectionTree build much faster.
708 Tokens.indexExpandedTokens();
709 std::vector<Decl *> ParsedDecls = Action->takeTopLevelDecls();
710 // AST traversals should exclude the preamble, to avoid performance cliffs.
711 Clang->getASTContext().setTraversalScope(ParsedDecls);
712 if (!CTChecks.empty()) {
713 // Run the AST-dependent part of the clang-tidy checks.
714 // (The preprocessor part ran already, via PPCallbacks).
715 trace::Span Tracer("ClangTidyMatch");
716 CTFinder.matchAST(Context&: Clang->getASTContext());
717 }
718
719 // XXX: This is messy: clang-tidy checks flush some diagnostics at EOF.
720 // However Action->EndSourceFile() would destroy the ASTContext!
721 // So just inform the preprocessor of EOF, while keeping everything alive.
722 PP.EndSourceFile();
723 // UnitDiagsConsumer is local, we can not store it in CompilerInstance that
724 // has a longer lifetime.
725 Clang->getDiagnostics().setClient(client: new IgnoreDiagnostics);
726 // CompilerInstance won't run this callback, do it directly.
727 ASTDiags.EndSourceFile();
728
729 std::vector<Diag> Diags = CompilerInvocationDiags;
730 // FIXME: Also skip generation of diagnostics altogether to speed up ast
731 // builds when we are patching a stale preamble.
732 // Add diagnostics from the preamble, if any.
733 if (Preamble)
734 llvm::append_range(C&: Diags, R: Patch->patchedDiags());
735 // Finally, add diagnostics coming from the AST.
736 {
737 std::vector<Diag> D = ASTDiags.take(Tidy: &*CTContext);
738 Diags.insert(position: Diags.end(), first: D.begin(), last: D.end());
739 }
740 ParsedAST Result(Filename, Inputs.Version, std::move(Preamble),
741 std::move(Clang), std::move(Action), std::move(Tokens),
742 std::move(Macros), std::move(Marks), std::move(ParsedDecls),
743 std::move(Diags), std::move(Includes), std::move(PI));
744 llvm::move(Range: getIncludeCleanerDiags(AST&: Result, Code: Inputs.Contents),
745 Out: std::back_inserter(x&: Result.Diags));
746 return std::move(Result);
747}
748
749ParsedAST::ParsedAST(ParsedAST &&Other) = default;
750
751ParsedAST &ParsedAST::operator=(ParsedAST &&Other) = default;
752
753ParsedAST::~ParsedAST() {
754 if (Action) {
755 // We already notified the PP of end-of-file earlier, so detach it first.
756 // We must keep it alive until after EndSourceFile(), Sema relies on this.
757 auto PP = Clang->getPreprocessorPtr(); // Keep PP alive for now.
758 Clang->setPreprocessor(nullptr); // Detach so we don't send EOF again.
759 Action->EndSourceFile(); // Destroy ASTContext and Sema.
760 // Now Sema is gone, it's safe for PP to go out of scope.
761 }
762}
763
764ASTContext &ParsedAST::getASTContext() { return Clang->getASTContext(); }
765
766const ASTContext &ParsedAST::getASTContext() const {
767 return Clang->getASTContext();
768}
769
770Sema &ParsedAST::getSema() { return Clang->getSema(); }
771
772Preprocessor &ParsedAST::getPreprocessor() { return Clang->getPreprocessor(); }
773
774std::shared_ptr<Preprocessor> ParsedAST::getPreprocessorPtr() {
775 return Clang->getPreprocessorPtr();
776}
777
778const Preprocessor &ParsedAST::getPreprocessor() const {
779 return Clang->getPreprocessor();
780}
781
782llvm::ArrayRef<Decl *> ParsedAST::getLocalTopLevelDecls() {
783 return LocalTopLevelDecls;
784}
785
786llvm::ArrayRef<const Decl *> ParsedAST::getLocalTopLevelDecls() const {
787 return LocalTopLevelDecls;
788}
789
790const MainFileMacros &ParsedAST::getMacros() const { return Macros; }
791const std::vector<PragmaMark> &ParsedAST::getMarks() const { return Marks; }
792
793std::size_t ParsedAST::getUsedBytes() const {
794 auto &AST = getASTContext();
795 // FIXME(ibiryukov): we do not account for the dynamically allocated part of
796 // Message and Fixes inside each diagnostic.
797 std::size_t Total =
798 clangd::getUsedBytes(Vec: LocalTopLevelDecls) + clangd::getUsedBytes(Vec: Diags);
799
800 // FIXME: the rest of the function is almost a direct copy-paste from
801 // libclang's clang_getCXTUResourceUsage. We could share the implementation.
802
803 // Sum up various allocators inside the ast context and the preprocessor.
804 Total += AST.getASTAllocatedMemory();
805 Total += AST.getSideTableAllocatedMemory();
806 Total += AST.Idents.getAllocator().getTotalMemory();
807 Total += AST.Selectors.getTotalMemory();
808
809 Total += AST.getSourceManager().getContentCacheSize();
810 Total += AST.getSourceManager().getDataStructureSizes();
811 Total += AST.getSourceManager().getMemoryBufferSizes().malloc_bytes;
812
813 if (ExternalASTSource *Ext = AST.getExternalSource())
814 Total += Ext->getMemoryBufferSizes().malloc_bytes;
815
816 const Preprocessor &PP = getPreprocessor();
817 Total += PP.getTotalMemory();
818 if (PreprocessingRecord *PRec = PP.getPreprocessingRecord())
819 Total += PRec->getTotalMemory();
820 Total += PP.getHeaderSearchInfo().getTotalMemory();
821
822 return Total;
823}
824
825const IncludeStructure &ParsedAST::getIncludeStructure() const {
826 return Includes;
827}
828
829ParsedAST::ParsedAST(PathRef TUPath, llvm::StringRef Version,
830 std::shared_ptr<const PreambleData> Preamble,
831 std::unique_ptr<CompilerInstance> Clang,
832 std::unique_ptr<FrontendAction> Action,
833 syntax::TokenBuffer Tokens, MainFileMacros Macros,
834 std::vector<PragmaMark> Marks,
835 std::vector<Decl *> LocalTopLevelDecls,
836 std::vector<Diag> Diags, IncludeStructure Includes,
837 include_cleaner::PragmaIncludes PI)
838 : TUPath(TUPath), Version(Version), Preamble(std::move(Preamble)),
839 Clang(std::move(Clang)), Action(std::move(Action)),
840 Tokens(std::move(Tokens)), Macros(std::move(Macros)),
841 Marks(std::move(Marks)), Diags(std::move(Diags)),
842 LocalTopLevelDecls(std::move(LocalTopLevelDecls)),
843 Includes(std::move(Includes)), PI(std::move(PI)),
844 Resolver(std::make_unique<HeuristicResolver>(args&: getASTContext())) {
845 assert(this->Clang);
846 assert(this->Action);
847}
848
849const include_cleaner::PragmaIncludes &ParsedAST::getPragmaIncludes() const {
850 return PI;
851}
852
853std::optional<llvm::StringRef> ParsedAST::preambleVersion() const {
854 if (!Preamble)
855 return std::nullopt;
856 return llvm::StringRef(Preamble->Version);
857}
858
859llvm::ArrayRef<Diag> ParsedAST::getDiagnostics() const { return Diags; }
860} // namespace clangd
861} // namespace clang
862

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