1 //===- DiagnosticRenderer.cpp - Diagnostic Pretty-Printing ----------------===//
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 "clang/Frontend/DiagnosticRenderer.h"
10 #include "clang/Basic/Diagnostic.h"
11 #include "clang/Basic/DiagnosticOptions.h"
12 #include "clang/Basic/LLVM.h"
13 #include "clang/Basic/SourceLocation.h"
14 #include "clang/Basic/SourceManager.h"
15 #include "clang/Edit/Commit.h"
16 #include "clang/Edit/EditedSource.h"
17 #include "clang/Edit/EditsReceiver.h"
18 #include "clang/Lex/Lexer.h"
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/None.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/Support/raw_ostream.h"
31 using namespace clang;
33 DiagnosticRenderer::DiagnosticRenderer(const LangOptions &LangOpts,
34 DiagnosticOptions *DiagOpts)
35 : LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
37 DiagnosticRenderer::~DiagnosticRenderer() = default;
41 class FixitReceiver : public edit::EditsReceiver {
42 SmallVectorImpl<FixItHint> &MergedFixits;
45 FixitReceiver(SmallVectorImpl<FixItHint> &MergedFixits)
46 : MergedFixits(MergedFixits) {}
48 void insert(SourceLocation loc, StringRef text) override {
49 MergedFixits.push_back(FixItHint::CreateInsertion(loc, text));
52 void replace(CharSourceRange range, StringRef text) override {
53 MergedFixits.push_back(FixItHint::CreateReplacement(range, text));
59 static void mergeFixits(ArrayRef<FixItHint> FixItHints,
60 const SourceManager &SM, const LangOptions &LangOpts,
61 SmallVectorImpl<FixItHint> &MergedFixits) {
62 edit::Commit commit(SM, LangOpts);
63 for (const auto &Hint : FixItHints)
64 if (Hint.CodeToInsert.empty()) {
65 if (Hint.InsertFromRange.isValid())
66 commit.insertFromRange(Hint.RemoveRange.getBegin(),
67 Hint.InsertFromRange, /*afterToken=*/false,
68 Hint.BeforePreviousInsertions);
70 commit.remove(Hint.RemoveRange);
72 if (Hint.RemoveRange.isTokenRange() ||
73 Hint.RemoveRange.getBegin() != Hint.RemoveRange.getEnd())
74 commit.replace(Hint.RemoveRange, Hint.CodeToInsert);
76 commit.insert(Hint.RemoveRange.getBegin(), Hint.CodeToInsert,
77 /*afterToken=*/false, Hint.BeforePreviousInsertions);
80 edit::EditedSource Editor(SM, LangOpts);
81 if (Editor.commit(commit)) {
82 FixitReceiver Rec(MergedFixits);
83 Editor.applyRewrites(Rec);
87 void DiagnosticRenderer::emitDiagnostic(FullSourceLoc Loc,
88 DiagnosticsEngine::Level Level,
90 ArrayRef<CharSourceRange> Ranges,
91 ArrayRef<FixItHint> FixItHints,
93 assert(Loc.hasManager() || Loc.isInvalid());
95 beginDiagnostic(D, Level);
98 // If we have no source location, just emit the diagnostic message.
99 emitDiagnosticMessage(Loc, PresumedLoc(), Level, Message, Ranges, D);
101 // Get the ranges into a local array we can hack on.
102 SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
105 SmallVector<FixItHint, 8> MergedFixits;
106 if (!FixItHints.empty()) {
107 mergeFixits(FixItHints, Loc.getManager(), LangOpts, MergedFixits);
108 FixItHints = MergedFixits;
111 for (const auto &Hint : FixItHints)
112 if (Hint.RemoveRange.isValid())
113 MutableRanges.push_back(Hint.RemoveRange);
115 FullSourceLoc UnexpandedLoc = Loc;
117 // Find the ultimate expansion location for the diagnostic.
118 Loc = Loc.getFileLoc();
120 PresumedLoc PLoc = Loc.getPresumedLoc(DiagOpts->ShowPresumedLoc);
122 // First, if this diagnostic is not in the main file, print out the
123 // "included from" lines.
124 emitIncludeStack(Loc, PLoc, Level);
126 // Next, emit the actual diagnostic message and caret.
127 emitDiagnosticMessage(Loc, PLoc, Level, Message, Ranges, D);
128 emitCaret(Loc, Level, MutableRanges, FixItHints);
130 // If this location is within a macro, walk from UnexpandedLoc up to Loc
131 // and produce a macro backtrace.
132 if (UnexpandedLoc.isValid() && UnexpandedLoc.isMacroID()) {
133 emitMacroExpansions(UnexpandedLoc, Level, MutableRanges, FixItHints);
140 endDiagnostic(D, Level);
143 void DiagnosticRenderer::emitStoredDiagnostic(StoredDiagnostic &Diag) {
144 emitDiagnostic(Diag.getLocation(), Diag.getLevel(), Diag.getMessage(),
145 Diag.getRanges(), Diag.getFixIts(),
149 void DiagnosticRenderer::emitBasicNote(StringRef Message) {
150 emitDiagnosticMessage(FullSourceLoc(), PresumedLoc(), DiagnosticsEngine::Note,
151 Message, None, DiagOrStoredDiag());
154 /// Prints an include stack when appropriate for a particular
155 /// diagnostic level and location.
157 /// This routine handles all the logic of suppressing particular include
158 /// stacks (such as those for notes) and duplicate include stacks when
159 /// repeated warnings occur within the same file. It also handles the logic
160 /// of customizing the formatting and display of the include stack.
162 /// \param Loc The diagnostic location.
163 /// \param PLoc The presumed location of the diagnostic location.
164 /// \param Level The diagnostic level of the message this stack pertains to.
165 void DiagnosticRenderer::emitIncludeStack(FullSourceLoc Loc, PresumedLoc PLoc,
166 DiagnosticsEngine::Level Level) {
167 FullSourceLoc IncludeLoc =
168 PLoc.isInvalid() ? FullSourceLoc()
169 : FullSourceLoc(PLoc.getIncludeLoc(), Loc.getManager());
171 // Skip redundant include stacks altogether.
172 if (LastIncludeLoc == IncludeLoc)
175 LastIncludeLoc = IncludeLoc;
177 if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
180 if (IncludeLoc.isValid())
181 emitIncludeStackRecursively(IncludeLoc);
183 emitModuleBuildStack(Loc.getManager());
184 emitImportStack(Loc);
188 /// Helper to recursively walk up the include stack and print each layer
189 /// on the way back down.
190 void DiagnosticRenderer::emitIncludeStackRecursively(FullSourceLoc Loc) {
191 if (Loc.isInvalid()) {
192 emitModuleBuildStack(Loc.getManager());
196 PresumedLoc PLoc = Loc.getPresumedLoc(DiagOpts->ShowPresumedLoc);
197 if (PLoc.isInvalid())
200 // If this source location was imported from a module, print the module
201 // import stack rather than the
202 // FIXME: We want submodule granularity here.
203 std::pair<FullSourceLoc, StringRef> Imported = Loc.getModuleImportLoc();
204 if (!Imported.second.empty()) {
205 // This location was imported by a module. Emit the module import stack.
206 emitImportStackRecursively(Imported.first, Imported.second);
210 // Emit the other include frames first.
211 emitIncludeStackRecursively(
212 FullSourceLoc(PLoc.getIncludeLoc(), Loc.getManager()));
214 // Emit the inclusion text/note.
215 emitIncludeLocation(Loc, PLoc);
218 /// Emit the module import stack associated with the current location.
219 void DiagnosticRenderer::emitImportStack(FullSourceLoc Loc) {
220 if (Loc.isInvalid()) {
221 emitModuleBuildStack(Loc.getManager());
225 std::pair<FullSourceLoc, StringRef> NextImportLoc = Loc.getModuleImportLoc();
226 emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second);
229 /// Helper to recursively walk up the import stack and print each layer
230 /// on the way back down.
231 void DiagnosticRenderer::emitImportStackRecursively(FullSourceLoc Loc,
232 StringRef ModuleName) {
233 if (ModuleName.empty()) {
237 PresumedLoc PLoc = Loc.getPresumedLoc(DiagOpts->ShowPresumedLoc);
239 // Emit the other import frames first.
240 std::pair<FullSourceLoc, StringRef> NextImportLoc = Loc.getModuleImportLoc();
241 emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second);
243 // Emit the inclusion text/note.
244 emitImportLocation(Loc, PLoc, ModuleName);
247 /// Emit the module build stack, for cases where a module is (re-)built
249 void DiagnosticRenderer::emitModuleBuildStack(const SourceManager &SM) {
250 ModuleBuildStack Stack = SM.getModuleBuildStack();
251 for (const auto &I : Stack) {
252 emitBuildingModuleLocation(I.second, I.second.getPresumedLoc(
253 DiagOpts->ShowPresumedLoc),
258 /// A recursive function to trace all possible backtrace locations
259 /// to match the \p CaretLocFileID.
260 static SourceLocation
261 retrieveMacroLocation(SourceLocation Loc, FileID MacroFileID,
263 const SmallVectorImpl<FileID> &CommonArgExpansions,
264 bool IsBegin, const SourceManager *SM,
265 bool &IsTokenRange) {
266 assert(SM->getFileID(Loc) == MacroFileID);
267 if (MacroFileID == CaretFileID)
269 if (!Loc.isMacroID())
272 CharSourceRange MacroRange, MacroArgRange;
274 if (SM->isMacroArgExpansion(Loc)) {
275 // Only look at the immediate spelling location of this macro argument if
276 // the other location in the source range is also present in that expansion.
277 if (std::binary_search(CommonArgExpansions.begin(),
278 CommonArgExpansions.end(), MacroFileID))
280 CharSourceRange(SM->getImmediateSpellingLoc(Loc), IsTokenRange);
281 MacroArgRange = SM->getImmediateExpansionRange(Loc);
283 MacroRange = SM->getImmediateExpansionRange(Loc);
285 CharSourceRange(SM->getImmediateSpellingLoc(Loc), IsTokenRange);
288 SourceLocation MacroLocation =
289 IsBegin ? MacroRange.getBegin() : MacroRange.getEnd();
290 if (MacroLocation.isValid()) {
291 MacroFileID = SM->getFileID(MacroLocation);
292 bool TokenRange = IsBegin ? IsTokenRange : MacroRange.isTokenRange();
294 retrieveMacroLocation(MacroLocation, MacroFileID, CaretFileID,
295 CommonArgExpansions, IsBegin, SM, TokenRange);
296 if (MacroLocation.isValid()) {
297 IsTokenRange = TokenRange;
298 return MacroLocation;
302 // If we moved the end of the range to an expansion location, we now have
303 // a range of the same kind as the expansion range.
305 IsTokenRange = MacroArgRange.isTokenRange();
307 SourceLocation MacroArgLocation =
308 IsBegin ? MacroArgRange.getBegin() : MacroArgRange.getEnd();
309 MacroFileID = SM->getFileID(MacroArgLocation);
310 return retrieveMacroLocation(MacroArgLocation, MacroFileID, CaretFileID,
311 CommonArgExpansions, IsBegin, SM, IsTokenRange);
314 /// Walk up the chain of macro expansions and collect the FileIDs identifying the
316 static void getMacroArgExpansionFileIDs(SourceLocation Loc,
317 SmallVectorImpl<FileID> &IDs,
318 bool IsBegin, const SourceManager *SM) {
319 while (Loc.isMacroID()) {
320 if (SM->isMacroArgExpansion(Loc)) {
321 IDs.push_back(SM->getFileID(Loc));
322 Loc = SM->getImmediateSpellingLoc(Loc);
324 auto ExpRange = SM->getImmediateExpansionRange(Loc);
325 Loc = IsBegin ? ExpRange.getBegin() : ExpRange.getEnd();
330 /// Collect the expansions of the begin and end locations and compute the set
331 /// intersection. Produces a sorted vector of FileIDs in CommonArgExpansions.
332 static void computeCommonMacroArgExpansionFileIDs(
333 SourceLocation Begin, SourceLocation End, const SourceManager *SM,
334 SmallVectorImpl<FileID> &CommonArgExpansions) {
335 SmallVector<FileID, 4> BeginArgExpansions;
336 SmallVector<FileID, 4> EndArgExpansions;
337 getMacroArgExpansionFileIDs(Begin, BeginArgExpansions, /*IsBegin=*/true, SM);
338 getMacroArgExpansionFileIDs(End, EndArgExpansions, /*IsBegin=*/false, SM);
339 llvm::sort(BeginArgExpansions);
340 llvm::sort(EndArgExpansions);
341 std::set_intersection(BeginArgExpansions.begin(), BeginArgExpansions.end(),
342 EndArgExpansions.begin(), EndArgExpansions.end(),
343 std::back_inserter(CommonArgExpansions));
346 // Helper function to fix up source ranges. It takes in an array of ranges,
347 // and outputs an array of ranges where we want to draw the range highlighting
348 // around the location specified by CaretLoc.
350 // To find locations which correspond to the caret, we crawl the macro caller
351 // chain for the beginning and end of each range. If the caret location
352 // is in a macro expansion, we search each chain for a location
353 // in the same expansion as the caret; otherwise, we crawl to the top of
354 // each chain. Two locations are part of the same macro expansion
355 // iff the FileID is the same.
357 mapDiagnosticRanges(FullSourceLoc CaretLoc, ArrayRef<CharSourceRange> Ranges,
358 SmallVectorImpl<CharSourceRange> &SpellingRanges) {
359 FileID CaretLocFileID = CaretLoc.getFileID();
361 const SourceManager *SM = &CaretLoc.getManager();
363 for (const auto &Range : Ranges) {
364 if (Range.isInvalid())
367 SourceLocation Begin = Range.getBegin(), End = Range.getEnd();
368 bool IsTokenRange = Range.isTokenRange();
370 FileID BeginFileID = SM->getFileID(Begin);
371 FileID EndFileID = SM->getFileID(End);
373 // Find the common parent for the beginning and end of the range.
375 // First, crawl the expansion chain for the beginning of the range.
376 llvm::SmallDenseMap<FileID, SourceLocation> BeginLocsMap;
377 while (Begin.isMacroID() && BeginFileID != EndFileID) {
378 BeginLocsMap[BeginFileID] = Begin;
379 Begin = SM->getImmediateExpansionRange(Begin).getBegin();
380 BeginFileID = SM->getFileID(Begin);
383 // Then, crawl the expansion chain for the end of the range.
384 if (BeginFileID != EndFileID) {
385 while (End.isMacroID() && !BeginLocsMap.count(EndFileID)) {
386 auto Exp = SM->getImmediateExpansionRange(End);
387 IsTokenRange = Exp.isTokenRange();
389 EndFileID = SM->getFileID(End);
391 if (End.isMacroID()) {
392 Begin = BeginLocsMap[EndFileID];
393 BeginFileID = EndFileID;
397 // Do the backtracking.
398 SmallVector<FileID, 4> CommonArgExpansions;
399 computeCommonMacroArgExpansionFileIDs(Begin, End, SM, CommonArgExpansions);
400 Begin = retrieveMacroLocation(Begin, BeginFileID, CaretLocFileID,
401 CommonArgExpansions, /*IsBegin=*/true, SM,
403 End = retrieveMacroLocation(End, BeginFileID, CaretLocFileID,
404 CommonArgExpansions, /*IsBegin=*/false, SM,
406 if (Begin.isInvalid() || End.isInvalid()) continue;
408 // Return the spelling location of the beginning and end of the range.
409 Begin = SM->getSpellingLoc(Begin);
410 End = SM->getSpellingLoc(End);
412 SpellingRanges.push_back(CharSourceRange(SourceRange(Begin, End),
417 void DiagnosticRenderer::emitCaret(FullSourceLoc Loc,
418 DiagnosticsEngine::Level Level,
419 ArrayRef<CharSourceRange> Ranges,
420 ArrayRef<FixItHint> Hints) {
421 SmallVector<CharSourceRange, 4> SpellingRanges;
422 mapDiagnosticRanges(Loc, Ranges, SpellingRanges);
423 emitCodeContext(Loc, Level, SpellingRanges, Hints);
426 /// A helper function for emitMacroExpansion to print the
427 /// macro expansion message
428 void DiagnosticRenderer::emitSingleMacroExpansion(
429 FullSourceLoc Loc, DiagnosticsEngine::Level Level,
430 ArrayRef<CharSourceRange> Ranges) {
431 // Find the spelling location for the macro definition. We must use the
432 // spelling location here to avoid emitting a macro backtrace for the note.
433 FullSourceLoc SpellingLoc = Loc.getSpellingLoc();
435 // Map the ranges into the FileID of the diagnostic location.
436 SmallVector<CharSourceRange, 4> SpellingRanges;
437 mapDiagnosticRanges(Loc, Ranges, SpellingRanges);
439 SmallString<100> MessageStorage;
440 llvm::raw_svector_ostream Message(MessageStorage);
441 StringRef MacroName = Lexer::getImmediateMacroNameForDiagnostics(
442 Loc, Loc.getManager(), LangOpts);
443 if (MacroName.empty())
444 Message << "expanded from here";
446 Message << "expanded from macro '" << MacroName << "'";
448 emitDiagnostic(SpellingLoc, DiagnosticsEngine::Note, Message.str(),
449 SpellingRanges, None);
452 /// Check that the macro argument location of Loc starts with ArgumentLoc.
453 /// The starting location of the macro expansions is used to differeniate
454 /// different macro expansions.
455 static bool checkLocForMacroArgExpansion(SourceLocation Loc,
456 const SourceManager &SM,
457 SourceLocation ArgumentLoc) {
458 SourceLocation MacroLoc;
459 if (SM.isMacroArgExpansion(Loc, &MacroLoc)) {
460 if (ArgumentLoc == MacroLoc) return true;
466 /// Check if all the locations in the range have the same macro argument
467 /// expansion, and that the expansion starts with ArgumentLoc.
468 static bool checkRangeForMacroArgExpansion(CharSourceRange Range,
469 const SourceManager &SM,
470 SourceLocation ArgumentLoc) {
471 SourceLocation BegLoc = Range.getBegin(), EndLoc = Range.getEnd();
472 while (BegLoc != EndLoc) {
473 if (!checkLocForMacroArgExpansion(BegLoc, SM, ArgumentLoc))
475 BegLoc.getLocWithOffset(1);
478 return checkLocForMacroArgExpansion(BegLoc, SM, ArgumentLoc);
481 /// A helper function to check if the current ranges are all inside the same
482 /// macro argument expansion as Loc.
483 static bool checkRangesForMacroArgExpansion(FullSourceLoc Loc,
484 ArrayRef<CharSourceRange> Ranges) {
485 assert(Loc.isMacroID() && "Must be a macro expansion!");
487 SmallVector<CharSourceRange, 4> SpellingRanges;
488 mapDiagnosticRanges(Loc, Ranges, SpellingRanges);
490 /// Count all valid ranges.
491 unsigned ValidCount = 0;
492 for (const auto &Range : Ranges)
496 if (ValidCount > SpellingRanges.size())
499 /// To store the source location of the argument location.
500 FullSourceLoc ArgumentLoc;
502 /// Set the ArgumentLoc to the beginning location of the expansion of Loc
503 /// so to check if the ranges expands to the same beginning location.
504 if (!Loc.isMacroArgExpansion(&ArgumentLoc))
507 for (const auto &Range : SpellingRanges)
508 if (!checkRangeForMacroArgExpansion(Range, Loc.getManager(), ArgumentLoc))
514 /// Recursively emit notes for each macro expansion and caret
515 /// diagnostics where appropriate.
517 /// Walks up the macro expansion stack printing expansion notes, the code
518 /// snippet, caret, underlines and FixItHint display as appropriate at each
521 /// \param Loc The location for this caret.
522 /// \param Level The diagnostic level currently being emitted.
523 /// \param Ranges The underlined ranges for this code snippet.
524 /// \param Hints The FixIt hints active for this diagnostic.
525 void DiagnosticRenderer::emitMacroExpansions(FullSourceLoc Loc,
526 DiagnosticsEngine::Level Level,
527 ArrayRef<CharSourceRange> Ranges,
528 ArrayRef<FixItHint> Hints) {
529 assert(Loc.isValid() && "must have a valid source location here");
530 const SourceManager &SM = Loc.getManager();
531 SourceLocation L = Loc;
533 // Produce a stack of macro backtraces.
534 SmallVector<SourceLocation, 8> LocationStack;
535 unsigned IgnoredEnd = 0;
536 while (L.isMacroID()) {
537 // If this is the expansion of a macro argument, point the caret at the
538 // use of the argument in the definition of the macro, not the expansion.
539 if (SM.isMacroArgExpansion(L))
540 LocationStack.push_back(SM.getImmediateExpansionRange(L).getBegin());
542 LocationStack.push_back(L);
544 if (checkRangesForMacroArgExpansion(FullSourceLoc(L, SM), Ranges))
545 IgnoredEnd = LocationStack.size();
547 L = SM.getImmediateMacroCallerLoc(L);
549 // Once the location no longer points into a macro, try stepping through
550 // the last found location. This sometimes produces additional useful
553 L = SM.getImmediateMacroCallerLoc(LocationStack.back());
554 assert(L.isValid() && "must have a valid source location here");
557 LocationStack.erase(LocationStack.begin(),
558 LocationStack.begin() + IgnoredEnd);
560 unsigned MacroDepth = LocationStack.size();
561 unsigned MacroLimit = DiagOpts->MacroBacktraceLimit;
562 if (MacroDepth <= MacroLimit || MacroLimit == 0) {
563 for (auto I = LocationStack.rbegin(), E = LocationStack.rend();
565 emitSingleMacroExpansion(FullSourceLoc(*I, SM), Level, Ranges);
569 unsigned MacroStartMessages = MacroLimit / 2;
570 unsigned MacroEndMessages = MacroLimit / 2 + MacroLimit % 2;
572 for (auto I = LocationStack.rbegin(),
573 E = LocationStack.rbegin() + MacroStartMessages;
575 emitSingleMacroExpansion(FullSourceLoc(*I, SM), Level, Ranges);
577 SmallString<200> MessageStorage;
578 llvm::raw_svector_ostream Message(MessageStorage);
579 Message << "(skipping " << (MacroDepth - MacroLimit)
580 << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
582 emitBasicNote(Message.str());
584 for (auto I = LocationStack.rend() - MacroEndMessages,
585 E = LocationStack.rend();
587 emitSingleMacroExpansion(FullSourceLoc(*I, SM), Level, Ranges);
590 DiagnosticNoteRenderer::~DiagnosticNoteRenderer() = default;
592 void DiagnosticNoteRenderer::emitIncludeLocation(FullSourceLoc Loc,
594 // Generate a note indicating the include location.
595 SmallString<200> MessageStorage;
596 llvm::raw_svector_ostream Message(MessageStorage);
597 Message << "in file included from " << PLoc.getFilename() << ':'
598 << PLoc.getLine() << ":";
599 emitNote(Loc, Message.str());
602 void DiagnosticNoteRenderer::emitImportLocation(FullSourceLoc Loc,
604 StringRef ModuleName) {
605 // Generate a note indicating the include location.
606 SmallString<200> MessageStorage;
607 llvm::raw_svector_ostream Message(MessageStorage);
608 Message << "in module '" << ModuleName;
610 Message << "' imported from " << PLoc.getFilename() << ':'
613 emitNote(Loc, Message.str());
616 void DiagnosticNoteRenderer::emitBuildingModuleLocation(FullSourceLoc Loc,
618 StringRef ModuleName) {
619 // Generate a note indicating the include location.
620 SmallString<200> MessageStorage;
621 llvm::raw_svector_ostream Message(MessageStorage);
623 Message << "while building module '" << ModuleName << "' imported from "
624 << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
626 Message << "while building module '" << ModuleName << "':";
627 emitNote(Loc, Message.str());