1 //===--- IncludeCleaner.cpp - Unused/Missing Headers Analysis ---*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 #include "IncludeCleaner.h"
10 #include "Diagnostics.h"
12 #include "ParsedAST.h"
15 #include "SourceCode.h"
16 #include "clang-include-cleaner/Analysis.h"
17 #include "clang-include-cleaner/IncludeSpeller.h"
18 #include "clang-include-cleaner/Record.h"
19 #include "clang-include-cleaner/Types.h"
20 #include "support/Logger.h"
21 #include "support/Path.h"
22 #include "support/Trace.h"
23 #include "clang/AST/ASTContext.h"
24 #include "clang/Basic/Diagnostic.h"
25 #include "clang/Basic/LLVM.h"
26 #include "clang/Basic/SourceLocation.h"
27 #include "clang/Basic/SourceManager.h"
28 #include "clang/Format/Format.h"
29 #include "clang/Lex/DirectoryLookup.h"
30 #include "clang/Lex/HeaderSearch.h"
31 #include "clang/Lex/Preprocessor.h"
32 #include "clang/Tooling/Core/Replacement.h"
33 #include "clang/Tooling/Inclusions/HeaderIncludes.h"
34 #include "clang/Tooling/Inclusions/StandardLibrary.h"
35 #include "clang/Tooling/Syntax/Tokens.h"
36 #include "llvm/ADT/ArrayRef.h"
37 #include "llvm/ADT/DenseSet.h"
38 #include "llvm/ADT/GenericUniformityImpl.h"
39 #include "llvm/ADT/STLExtras.h"
40 #include "llvm/ADT/SmallString.h"
41 #include "llvm/ADT/SmallVector.h"
42 #include "llvm/ADT/StringRef.h"
43 #include "llvm/Support/Error.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/FormatVariadic.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/Regex.h"
56 namespace clang::clangd
{
59 bool isIgnored(llvm::StringRef HeaderPath
, HeaderFilter IgnoreHeaders
) {
60 // Convert the path to Unix slashes and try to match against the filter.
61 llvm::SmallString
<64> NormalizedPath(HeaderPath
);
62 llvm::sys::path::native(NormalizedPath
, llvm::sys::path::Style::posix
);
63 for (auto &Filter
: IgnoreHeaders
) {
64 if (Filter(NormalizedPath
))
70 bool mayConsiderUnused(const Inclusion
&Inc
, ParsedAST
&AST
,
71 const include_cleaner::PragmaIncludes
*PI
,
72 bool AnalyzeAngledIncludes
) {
74 auto HID
= static_cast<IncludeStructure::HeaderID
>(*Inc
.HeaderID
);
75 auto FE
= AST
.getSourceManager().getFileManager().getFileRef(
76 AST
.getIncludeStructure().getRealPath(HID
));
78 if (FE
->getDir() == AST
.getPreprocessor()
79 .getHeaderSearchInfo()
83 if (PI
&& PI
->shouldKeep(*FE
))
85 // FIXME(kirillbobyrev): We currently do not support the umbrella headers.
86 // System headers are likely to be standard library headers.
87 // Until we have good support for umbrella headers, don't warn about them
88 // (unless analysis is explicitly enabled).
89 if (Inc
.Written
.front() == '<') {
90 if (tooling::stdlib::Header::named(Inc
.Written
))
92 if (!AnalyzeAngledIncludes
)
96 // Check if main file is the public interface for a private header. If so we
97 // shouldn't diagnose it as unused.
98 if (auto PHeader
= PI
->getPublic(*FE
); !PHeader
.empty()) {
99 PHeader
= PHeader
.trim("<>\"");
100 // Since most private -> public mappings happen in a verbatim way, we
101 // check textually here. This might go wrong in presence of symlinks or
102 // header mappings. But that's not different than rest of the places.
103 if (AST
.tuPath().ends_with(PHeader
))
107 // Headers without include guards have side effects and are not
108 // self-contained, skip them.
109 if (!AST
.getPreprocessor().getHeaderSearchInfo().isFileMultipleIncludeGuarded(
111 dlog("{0} doesn't have header guard and will not be considered unused",
118 std::vector
<Diag
> generateMissingIncludeDiagnostics(
119 ParsedAST
&AST
, llvm::ArrayRef
<MissingIncludeDiagInfo
> MissingIncludes
,
120 llvm::StringRef Code
, HeaderFilter IgnoreHeaders
, const ThreadsafeFS
&TFS
) {
121 std::vector
<Diag
> Result
;
122 const SourceManager
&SM
= AST
.getSourceManager();
123 const FileEntry
*MainFile
= SM
.getFileEntryForID(SM
.getMainFileID());
125 auto FileStyle
= getFormatStyleForFile(AST
.tuPath(), Code
, TFS
, false);
127 tooling::HeaderIncludes
HeaderIncludes(AST
.tuPath(), Code
,
128 FileStyle
.IncludeStyle
);
129 for (const auto &SymbolWithMissingInclude
: MissingIncludes
) {
130 llvm::StringRef ResolvedPath
=
131 SymbolWithMissingInclude
.Providers
.front().resolvedPath();
132 if (isIgnored(ResolvedPath
, IgnoreHeaders
)) {
133 dlog("IncludeCleaner: not diagnosing missing include {0}, filtered by "
139 std::string Spelling
= include_cleaner::spellHeader(
140 {SymbolWithMissingInclude
.Providers
.front(),
141 AST
.getPreprocessor().getHeaderSearchInfo(), MainFile
});
143 llvm::StringRef HeaderRef
{Spelling
};
144 bool Angled
= HeaderRef
.starts_with("<");
145 // We might suggest insertion of an existing include in edge cases, e.g.,
146 // include is present in a PP-disabled region, or spelling of the header
147 // turns out to be the same as one of the unresolved includes in the
149 std::optional
<tooling::Replacement
> Replacement
= HeaderIncludes
.insert(
150 HeaderRef
.trim("\"<>"), Angled
, tooling::IncludeDirective::Include
);
151 if (!Replacement
.has_value())
154 Diag
&D
= Result
.emplace_back();
156 llvm::formatv("No header providing \"{0}\" is directly included",
157 SymbolWithMissingInclude
.Symbol
.name());
158 D
.Name
= "missing-includes";
159 D
.Source
= Diag::DiagSource::Clangd
;
160 D
.File
= AST
.tuPath();
161 D
.InsideMainFile
= true;
162 // We avoid the "warning" severity here in favor of LSP's "information".
164 // Users treat most warnings on code being edited as high-priority.
165 // They don't think of include cleanups the same way: they want to edit
166 // lines with existing violations without fixing them.
167 // Diagnostics at the same level tend to be visually indistinguishable,
168 // and a few missing includes can cause many diagnostics.
169 // Marking these as "information" leaves them visible, but less intrusive.
171 // (These concerns don't apply to unused #include warnings: these are fewer,
172 // they appear on infrequently-edited lines with few other warnings, and
173 // the 'Unneccesary' tag often result in a different rendering)
175 // Usually clang's "note" severity usually has special semantics, being
176 // translated into LSP RelatedInformation of a parent diagnostic.
177 // But not here: these aren't processed by clangd's DiagnosticConsumer.
178 D
.Severity
= DiagnosticsEngine::Note
;
179 D
.Range
= clangd::Range
{
180 offsetToPosition(Code
,
181 SymbolWithMissingInclude
.SymRefRange
.beginOffset()),
182 offsetToPosition(Code
,
183 SymbolWithMissingInclude
.SymRefRange
.endOffset())};
184 auto &F
= D
.Fixes
.emplace_back();
185 F
.Message
= "#include " + Spelling
;
186 TextEdit Edit
= replacementToEdit(Code
, *Replacement
);
187 F
.Edits
.emplace_back(std::move(Edit
));
192 std::vector
<Diag
> generateUnusedIncludeDiagnostics(
193 PathRef FileName
, llvm::ArrayRef
<const Inclusion
*> UnusedIncludes
,
194 llvm::StringRef Code
, HeaderFilter IgnoreHeaders
) {
195 std::vector
<Diag
> Result
;
196 for (const auto *Inc
: UnusedIncludes
) {
197 if (isIgnored(Inc
->Resolved
, IgnoreHeaders
))
199 Diag
&D
= Result
.emplace_back();
201 llvm::formatv("included header {0} is not used directly",
202 llvm::sys::path::filename(
203 Inc
->Written
.substr(1, Inc
->Written
.size() - 2),
204 llvm::sys::path::Style::posix
));
205 D
.Name
= "unused-includes";
206 D
.Source
= Diag::DiagSource::Clangd
;
208 D
.InsideMainFile
= true;
209 D
.Severity
= DiagnosticsEngine::Warning
;
210 D
.Tags
.push_back(Unnecessary
);
211 D
.Range
= rangeTillEOL(Code
, Inc
->HashOffset
);
212 // FIXME(kirillbobyrev): Removing inclusion might break the code if the
213 // used headers are only reachable transitively through this one. Suggest
214 // including them directly instead.
215 // FIXME(kirillbobyrev): Add fix suggestion for adding IWYU pragmas
216 // (keep/export) remove the warning once we support IWYU pragmas.
217 auto &F
= D
.Fixes
.emplace_back();
218 F
.Message
= "remove #include directive";
219 F
.Edits
.emplace_back();
220 F
.Edits
.back().range
.start
.line
= Inc
->HashLine
;
221 F
.Edits
.back().range
.end
.line
= Inc
->HashLine
+ 1;
227 removeAllUnusedIncludes(llvm::ArrayRef
<Diag
> UnusedIncludes
) {
228 if (UnusedIncludes
.empty())
232 RemoveAll
.Message
= "remove all unused includes";
233 for (const auto &Diag
: UnusedIncludes
) {
234 assert(Diag
.Fixes
.size() == 1 && "Expected exactly one fix.");
235 RemoveAll
.Edits
.insert(RemoveAll
.Edits
.end(),
236 Diag
.Fixes
.front().Edits
.begin(),
237 Diag
.Fixes
.front().Edits
.end());
243 addAllMissingIncludes(llvm::ArrayRef
<Diag
> MissingIncludeDiags
) {
244 if (MissingIncludeDiags
.empty())
248 AddAllMissing
.Message
= "add all missing includes";
249 // A map to deduplicate the edits with the same new text.
250 // newText (#include "my_missing_header.h") -> TextEdit.
251 std::map
<std::string
, TextEdit
> Edits
;
252 for (const auto &Diag
: MissingIncludeDiags
) {
253 assert(Diag
.Fixes
.size() == 1 && "Expected exactly one fix.");
254 for (const auto &Edit
: Diag
.Fixes
.front().Edits
) {
255 Edits
.try_emplace(Edit
.newText
, Edit
);
258 for (auto &It
: Edits
)
259 AddAllMissing
.Edits
.push_back(std::move(It
.second
));
260 return AddAllMissing
;
262 Fix
fixAll(const Fix
&RemoveAllUnused
, const Fix
&AddAllMissing
) {
264 FixAll
.Message
= "fix all includes";
266 for (const auto &F
: RemoveAllUnused
.Edits
)
267 FixAll
.Edits
.push_back(F
);
268 for (const auto &F
: AddAllMissing
.Edits
)
269 FixAll
.Edits
.push_back(F
);
273 std::vector
<const Inclusion
*>
274 getUnused(ParsedAST
&AST
,
275 const llvm::DenseSet
<IncludeStructure::HeaderID
> &ReferencedFiles
,
276 bool AnalyzeAngledIncludes
) {
277 trace::Span
Tracer("IncludeCleaner::getUnused");
278 std::vector
<const Inclusion
*> Unused
;
279 for (const Inclusion
&MFI
: AST
.getIncludeStructure().MainFileIncludes
) {
282 auto IncludeID
= static_cast<IncludeStructure::HeaderID
>(*MFI
.HeaderID
);
283 if (ReferencedFiles
.contains(IncludeID
))
285 if (!mayConsiderUnused(MFI
, AST
, &AST
.getPragmaIncludes(),
286 AnalyzeAngledIncludes
)) {
287 dlog("{0} was not used, but is not eligible to be diagnosed as unused",
291 Unused
.push_back(&MFI
);
298 std::vector
<include_cleaner::SymbolReference
>
299 collectMacroReferences(ParsedAST
&AST
) {
300 const auto &SM
= AST
.getSourceManager();
301 auto &PP
= AST
.getPreprocessor();
302 std::vector
<include_cleaner::SymbolReference
> Macros
;
303 for (const auto &[_
, Refs
] : AST
.getMacros().MacroRefs
) {
304 for (const auto &Ref
: Refs
) {
305 auto Loc
= SM
.getComposedLoc(SM
.getMainFileID(), Ref
.StartOffset
);
306 const auto *Tok
= AST
.getTokens().spelledTokenContaining(Loc
);
309 auto Macro
= locateMacroAt(*Tok
, PP
);
312 auto DefLoc
= Macro
->NameLoc
;
313 if (!DefLoc
.isValid())
316 {include_cleaner::Macro
{/*Name=*/PP
.getIdentifierInfo(Tok
->text(SM
)),
319 Ref
.InConditionalDirective
? include_cleaner::RefType::Ambiguous
320 : include_cleaner::RefType::Explicit
});
327 include_cleaner::Includes
convertIncludes(const ParsedAST
&AST
) {
328 auto &SM
= AST
.getSourceManager();
330 include_cleaner::Includes ConvertedIncludes
;
331 // We satisfy Includes's contract that search dirs and included files have
332 // matching path styles: both ultimately use FileManager::getCanonicalName().
333 for (const auto &Dir
: AST
.getIncludeStructure().SearchPathsCanonical
)
334 ConvertedIncludes
.addSearchDirectory(Dir
);
336 for (const Inclusion
&Inc
: AST
.getIncludeStructure().MainFileIncludes
) {
337 include_cleaner::Include TransformedInc
;
338 llvm::StringRef WrittenRef
= llvm::StringRef(Inc
.Written
);
339 TransformedInc
.Spelled
= WrittenRef
.trim("\"<>");
340 TransformedInc
.HashLocation
=
341 SM
.getComposedLoc(SM
.getMainFileID(), Inc
.HashOffset
);
342 TransformedInc
.Line
= Inc
.HashLine
+ 1;
343 TransformedInc
.Angled
= WrittenRef
.starts_with("<");
344 // Inc.Resolved is canonicalized with clangd::getCanonicalPath(),
345 // which is based on FileManager::getCanonicalName(ParentDir).
346 auto FE
= SM
.getFileManager().getFileRef(Inc
.Resolved
);
348 elog("IncludeCleaner: Failed to get an entry for resolved path {0}: {1}",
349 Inc
.Resolved
, FE
.takeError());
352 TransformedInc
.Resolved
= *FE
;
353 ConvertedIncludes
.add(std::move(TransformedInc
));
355 return ConvertedIncludes
;
358 IncludeCleanerFindings
359 computeIncludeCleanerFindings(ParsedAST
&AST
, bool AnalyzeAngledIncludes
) {
360 // Interaction is only polished for C/CPP.
361 if (AST
.getLangOpts().ObjC
)
363 const auto &SM
= AST
.getSourceManager();
364 include_cleaner::Includes ConvertedIncludes
= convertIncludes(AST
);
365 const FileEntry
*MainFile
= SM
.getFileEntryForID(SM
.getMainFileID());
366 auto PreamblePatch
= PreamblePatch::getPatchEntry(AST
.tuPath(), SM
);
368 std::vector
<include_cleaner::SymbolReference
> Macros
=
369 collectMacroReferences(AST
);
370 std::vector
<MissingIncludeDiagInfo
> MissingIncludes
;
371 llvm::DenseSet
<IncludeStructure::HeaderID
> Used
;
372 trace::Span
Tracer("include_cleaner::walkUsed");
373 OptionalDirectoryEntryRef ResourceDir
= AST
.getPreprocessor()
374 .getHeaderSearchInfo()
377 include_cleaner::walkUsed(
378 AST
.getLocalTopLevelDecls(), /*MacroRefs=*/Macros
,
379 &AST
.getPragmaIncludes(), AST
.getPreprocessor(),
380 [&](const include_cleaner::SymbolReference
&Ref
,
381 llvm::ArrayRef
<include_cleaner::Header
> Providers
) {
382 bool Satisfied
= false;
383 for (const auto &H
: Providers
) {
384 if (H
.kind() == include_cleaner::Header::Physical
&&
385 (H
.physical() == MainFile
|| H
.physical() == PreamblePatch
||
386 H
.physical().getDir() == ResourceDir
)) {
390 for (auto *Inc
: ConvertedIncludes
.match(H
)) {
393 AST
.getIncludeStructure().getID(&Inc
->Resolved
->getFileEntry());
394 assert(HeaderID
.has_value() &&
395 "ConvertedIncludes only contains resolved includes.");
396 Used
.insert(*HeaderID
);
400 if (Satisfied
|| Providers
.empty() ||
401 Ref
.RT
!= include_cleaner::RefType::Explicit
)
404 // Check if we have any headers with the same spelling, in edge cases
405 // like `#include_next "foo.h"`, the user can't ever include the
406 // physical foo.h, but can have a spelling that refers to it.
407 // We postpone this check because spelling a header for every usage is
409 std::string Spelling
= include_cleaner::spellHeader(
410 {Providers
.front(), AST
.getPreprocessor().getHeaderSearchInfo(),
413 ConvertedIncludes
.match(include_cleaner::Header
{Spelling
})) {
416 AST
.getIncludeStructure().getID(&Inc
->Resolved
->getFileEntry());
417 assert(HeaderID
.has_value() &&
418 "ConvertedIncludes only contains resolved includes.");
419 Used
.insert(*HeaderID
);
424 // We actually always want to map usages to their spellings, but
425 // spelling locations can point into preamble section. Using these
426 // offsets could lead into crashes in presence of stale preambles. Hence
427 // we use "getFileLoc" instead to make sure it always points into main
429 // FIXME: Use presumed locations to map such usages back to patched
431 auto Loc
= SM
.getFileLoc(Ref
.RefLocation
);
432 // File locations can be outside of the main file if macro is expanded
433 // through an #include.
434 while (SM
.getFileID(Loc
) != SM
.getMainFileID())
435 Loc
= SM
.getIncludeLoc(SM
.getFileID(Loc
));
436 auto TouchingTokens
=
437 syntax::spelledTokensTouching(Loc
, AST
.getTokens());
438 assert(!TouchingTokens
.empty());
439 // Loc points to the start offset of the ref token, here we use the last
440 // element of the TouchingTokens, e.g. avoid getting the "::" for
442 MissingIncludeDiagInfo DiagInfo
{
443 Ref
.Target
, TouchingTokens
.back().range(SM
), Providers
};
444 MissingIncludes
.push_back(std::move(DiagInfo
));
446 // Put possibly equal diagnostics together for deduplication.
447 // The duplicates might be from macro arguments that get expanded multiple
449 llvm::stable_sort(MissingIncludes
, [](const MissingIncludeDiagInfo
&LHS
,
450 const MissingIncludeDiagInfo
&RHS
) {
451 // First sort by reference location.
452 if (LHS
.SymRefRange
!= RHS
.SymRefRange
) {
453 // We can get away just by comparing the offsets as all the ranges are in
455 return LHS
.SymRefRange
.beginOffset() < RHS
.SymRefRange
.beginOffset();
457 // For the same location, break ties using the symbol. Note that this won't
458 // be stable across runs.
459 using MapInfo
= llvm::DenseMapInfo
<include_cleaner::Symbol
>;
460 return MapInfo::getHashValue(LHS
.Symbol
) <
461 MapInfo::getHashValue(RHS
.Symbol
);
463 MissingIncludes
.erase(llvm::unique(MissingIncludes
), MissingIncludes
.end());
464 std::vector
<const Inclusion
*> UnusedIncludes
=
465 getUnused(AST
, Used
, AnalyzeAngledIncludes
);
466 return {std::move(UnusedIncludes
), std::move(MissingIncludes
)};
469 bool isPreferredProvider(const Inclusion
&Inc
,
470 const include_cleaner::Includes
&Includes
,
471 llvm::ArrayRef
<include_cleaner::Header
> Providers
) {
472 for (const auto &H
: Providers
) {
473 auto Matches
= Includes
.match(H
);
474 for (const include_cleaner::Include
*Match
: Matches
)
475 if (Match
->Line
== unsigned(Inc
.HashLine
+ 1))
476 return true; // this header is (equal) best
477 if (!Matches
.empty())
478 return false; // another header is better
480 return false; // no header provides the symbol
484 issueIncludeCleanerDiagnostics(ParsedAST
&AST
, llvm::StringRef Code
,
485 const IncludeCleanerFindings
&Findings
,
486 const ThreadsafeFS
&TFS
,
487 HeaderFilter IgnoreHeaders
) {
488 trace::Span
Tracer("IncludeCleaner::issueIncludeCleanerDiagnostics");
489 std::vector
<Diag
> UnusedIncludes
= generateUnusedIncludeDiagnostics(
490 AST
.tuPath(), Findings
.UnusedIncludes
, Code
, IgnoreHeaders
);
491 std::optional
<Fix
> RemoveAllUnused
= removeAllUnusedIncludes(UnusedIncludes
);
493 std::vector
<Diag
> MissingIncludeDiags
= generateMissingIncludeDiagnostics(
494 AST
, Findings
.MissingIncludes
, Code
, IgnoreHeaders
, TFS
);
495 std::optional
<Fix
> AddAllMissing
= addAllMissingIncludes(MissingIncludeDiags
);
497 std::optional
<Fix
> FixAll
;
498 if (RemoveAllUnused
&& AddAllMissing
)
499 FixAll
= fixAll(*RemoveAllUnused
, *AddAllMissing
);
501 auto AddBatchFix
= [](const std::optional
<Fix
> &F
, clang::clangd::Diag
*Out
) {
504 Out
->Fixes
.push_back(*F
);
506 for (auto &Diag
: MissingIncludeDiags
) {
507 AddBatchFix(MissingIncludeDiags
.size() > 1 ? AddAllMissing
: std::nullopt
,
509 AddBatchFix(FixAll
, &Diag
);
511 for (auto &Diag
: UnusedIncludes
) {
512 AddBatchFix(UnusedIncludes
.size() > 1 ? RemoveAllUnused
: std::nullopt
,
514 AddBatchFix(FixAll
, &Diag
);
517 auto Result
= std::move(MissingIncludeDiags
);
518 llvm::move(UnusedIncludes
, std::back_inserter(Result
));
522 } // namespace clang::clangd