DiagnosticRenderer.cpp revision adff43ad96defb28bad20d8335ab30beadd72ee8 
1//===--- DiagnosticRenderer.cpp - Diagnostic Pretty-Printing --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "clang/Frontend/DiagnosticRenderer.h"
11#include "clang/Basic/DiagnosticOptions.h"
12#include "clang/Basic/FileManager.h"
13#include "clang/Basic/SourceManager.h"
14#include "clang/Edit/Commit.h"
15#include "clang/Edit/EditedSource.h"
16#include "clang/Edit/EditsReceiver.h"
17#include "clang/Lex/Lexer.h"
18#include "llvm/ADT/SmallSet.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/Support/MemoryBuffer.h"
22#include "llvm/Support/raw_ostream.h"
23#include <algorithm>
24using namespace clang;
25
26/// \brief Retrieve the name of the immediate macro expansion.
27///
28/// This routine starts from a source location, and finds the name of the macro
29/// responsible for its immediate expansion. It looks through any intervening
30/// macro argument expansions to compute this. It returns a StringRef which
31/// refers to the SourceManager-owned buffer of the source where that macro
32/// name is spelled. Thus, the result shouldn't out-live that SourceManager.
33///
34/// This differs from Lexer::getImmediateMacroName in that any macro argument
35/// location will result in the topmost function macro that accepted it.
36/// e.g.
37/// \code
38///   MAC1( MAC2(foo) )
39/// \endcode
40/// for location of 'foo' token, this function will return "MAC1" while
41/// Lexer::getImmediateMacroName will return "MAC2".
42static StringRef getImmediateMacroName(SourceLocation Loc,
43                                       const SourceManager &SM,
44                                       const LangOptions &LangOpts) {
45   assert(Loc.isMacroID() && "Only reasonble to call this on macros");
46   // Walk past macro argument expanions.
47   while (SM.isMacroArgExpansion(Loc))
48     Loc = SM.getImmediateExpansionRange(Loc).first;
49
50   // If the macro's spelling has no FileID, then it's actually a token paste
51   // or stringization (or similar) and not a macro at all.
52   if (!SM.getFileEntryForID(SM.getFileID(SM.getSpellingLoc(Loc))))
53     return StringRef();
54
55   // Find the spelling location of the start of the non-argument expansion
56   // range. This is where the macro name was spelled in order to begin
57   // expanding this macro.
58   Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
59
60   // Dig out the buffer where the macro name was spelled and the extents of the
61   // name so that we can render it into the expansion note.
62   std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
63   unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
64   StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
65   return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
66}
67
68DiagnosticRenderer::DiagnosticRenderer(const LangOptions &LangOpts,
69                                       DiagnosticOptions *DiagOpts)
70  : LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
71
72DiagnosticRenderer::~DiagnosticRenderer() {}
73
74namespace {
75
76class FixitReceiver : public edit::EditsReceiver {
77  SmallVectorImpl<FixItHint> &MergedFixits;
78
79public:
80  FixitReceiver(SmallVectorImpl<FixItHint> &MergedFixits)
81    : MergedFixits(MergedFixits) { }
82  virtual void insert(SourceLocation loc, StringRef text) {
83    MergedFixits.push_back(FixItHint::CreateInsertion(loc, text));
84  }
85  virtual void replace(CharSourceRange range, StringRef text) {
86    MergedFixits.push_back(FixItHint::CreateReplacement(range, text));
87  }
88};
89
90}
91
92static void mergeFixits(ArrayRef<FixItHint> FixItHints,
93                        const SourceManager &SM, const LangOptions &LangOpts,
94                        SmallVectorImpl<FixItHint> &MergedFixits) {
95  edit::Commit commit(SM, LangOpts);
96  for (ArrayRef<FixItHint>::const_iterator
97         I = FixItHints.begin(), E = FixItHints.end(); I != E; ++I) {
98    const FixItHint &Hint = *I;
99    if (Hint.CodeToInsert.empty()) {
100      if (Hint.InsertFromRange.isValid())
101        commit.insertFromRange(Hint.RemoveRange.getBegin(),
102                           Hint.InsertFromRange, /*afterToken=*/false,
103                           Hint.BeforePreviousInsertions);
104      else
105        commit.remove(Hint.RemoveRange);
106    } else {
107      if (Hint.RemoveRange.isTokenRange() ||
108          Hint.RemoveRange.getBegin() != Hint.RemoveRange.getEnd())
109        commit.replace(Hint.RemoveRange, Hint.CodeToInsert);
110      else
111        commit.insert(Hint.RemoveRange.getBegin(), Hint.CodeToInsert,
112                    /*afterToken=*/false, Hint.BeforePreviousInsertions);
113    }
114  }
115
116  edit::EditedSource Editor(SM, LangOpts);
117  if (Editor.commit(commit)) {
118    FixitReceiver Rec(MergedFixits);
119    Editor.applyRewrites(Rec);
120  }
121}
122
123void DiagnosticRenderer::emitDiagnostic(SourceLocation Loc,
124                                        DiagnosticsEngine::Level Level,
125                                        StringRef Message,
126                                        ArrayRef<CharSourceRange> Ranges,
127                                        ArrayRef<FixItHint> FixItHints,
128                                        const SourceManager *SM,
129                                        DiagOrStoredDiag D) {
130  assert(SM || Loc.isInvalid());
131
132  beginDiagnostic(D, Level);
133
134  if (!Loc.isValid())
135    // If we have no source location, just emit the diagnostic message.
136    emitDiagnosticMessage(Loc, PresumedLoc(), Level, Message, Ranges, SM, D);
137  else {
138    // Get the ranges into a local array we can hack on.
139    SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
140                                                   Ranges.end());
141
142    llvm::SmallVector<FixItHint, 8> MergedFixits;
143    if (!FixItHints.empty()) {
144      mergeFixits(FixItHints, *SM, LangOpts, MergedFixits);
145      FixItHints = MergedFixits;
146    }
147
148    for (ArrayRef<FixItHint>::const_iterator I = FixItHints.begin(),
149         E = FixItHints.end();
150         I != E; ++I)
151      if (I->RemoveRange.isValid())
152        MutableRanges.push_back(I->RemoveRange);
153
154    SourceLocation UnexpandedLoc = Loc;
155
156    // Perform the same walk as emitMacroExpansions, to find the ultimate
157    // expansion location for the diagnostic.
158    while (Loc.isMacroID())
159      Loc = SM->getImmediateMacroCallerLoc(Loc);
160
161    PresumedLoc PLoc = SM->getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
162
163    // First, if this diagnostic is not in the main file, print out the
164    // "included from" lines.
165    emitIncludeStack(Loc, PLoc, Level, *SM);
166
167    // Next, emit the actual diagnostic message and caret.
168    emitDiagnosticMessage(Loc, PLoc, Level, Message, Ranges, SM, D);
169    emitCaret(Loc, Level, MutableRanges, FixItHints, *SM);
170
171    // If this location is within a macro, walk from UnexpandedLoc up to Loc
172    // and produce a macro backtrace.
173    if (UnexpandedLoc.isValid() && UnexpandedLoc.isMacroID()) {
174      unsigned MacroDepth = 0;
175      emitMacroExpansions(UnexpandedLoc, Level, MutableRanges, FixItHints, *SM,
176                          MacroDepth);
177    }
178  }
179
180  LastLoc = Loc;
181  LastLevel = Level;
182
183  endDiagnostic(D, Level);
184}
185
186
187void DiagnosticRenderer::emitStoredDiagnostic(StoredDiagnostic &Diag) {
188  emitDiagnostic(Diag.getLocation(), Diag.getLevel(), Diag.getMessage(),
189                 Diag.getRanges(), Diag.getFixIts(),
190                 Diag.getLocation().isValid() ? &Diag.getLocation().getManager()
191                                              : 0,
192                 &Diag);
193}
194
195/// \brief Prints an include stack when appropriate for a particular
196/// diagnostic level and location.
197///
198/// This routine handles all the logic of suppressing particular include
199/// stacks (such as those for notes) and duplicate include stacks when
200/// repeated warnings occur within the same file. It also handles the logic
201/// of customizing the formatting and display of the include stack.
202///
203/// \param Loc   The diagnostic location.
204/// \param PLoc  The presumed location of the diagnostic location.
205/// \param Level The diagnostic level of the message this stack pertains to.
206void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
207                                          PresumedLoc PLoc,
208                                          DiagnosticsEngine::Level Level,
209                                          const SourceManager &SM) {
210  SourceLocation IncludeLoc = PLoc.getIncludeLoc();
211
212  // Skip redundant include stacks altogether.
213  if (LastIncludeLoc == IncludeLoc)
214    return;
215
216  LastIncludeLoc = IncludeLoc;
217
218  if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
219    return;
220
221  if (IncludeLoc.isValid())
222    emitIncludeStackRecursively(IncludeLoc, SM);
223  else {
224    emitModuleBuildStack(SM);
225    emitImportStack(Loc, SM);
226  }
227}
228
229/// \brief Helper to recursivly walk up the include stack and print each layer
230/// on the way back down.
231void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc,
232                                                     const SourceManager &SM) {
233  if (Loc.isInvalid()) {
234    emitModuleBuildStack(SM);
235    return;
236  }
237
238  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
239  if (PLoc.isInvalid())
240    return;
241
242  // If this source location was imported from a module, print the module
243  // import stack rather than the
244  // FIXME: We want submodule granularity here.
245  std::pair<SourceLocation, StringRef> Imported = SM.getModuleImportLoc(Loc);
246  if (Imported.first.isValid()) {
247    // This location was imported by a module. Emit the module import stack.
248    emitImportStackRecursively(Imported.first, Imported.second, SM);
249    return;
250  }
251
252  // Emit the other include frames first.
253  emitIncludeStackRecursively(PLoc.getIncludeLoc(), SM);
254
255  // Emit the inclusion text/note.
256  emitIncludeLocation(Loc, PLoc, SM);
257}
258
259/// \brief Emit the module import stack associated with the current location.
260void DiagnosticRenderer::emitImportStack(SourceLocation Loc,
261                                         const SourceManager &SM) {
262  if (Loc.isInvalid()) {
263    emitModuleBuildStack(SM);
264    return;
265  }
266
267  std::pair<SourceLocation, StringRef> NextImportLoc
268    = SM.getModuleImportLoc(Loc);
269  emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second, SM);
270}
271
272/// \brief Helper to recursivly walk up the import stack and print each layer
273/// on the way back down.
274void DiagnosticRenderer::emitImportStackRecursively(SourceLocation Loc,
275                                                    StringRef ModuleName,
276                                                    const SourceManager &SM) {
277  if (Loc.isInvalid()) {
278    return;
279  }
280
281  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
282  if (PLoc.isInvalid())
283    return;
284
285  // Emit the other import frames first.
286  std::pair<SourceLocation, StringRef> NextImportLoc
287    = SM.getModuleImportLoc(Loc);
288  emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second, SM);
289
290  // Emit the inclusion text/note.
291  emitImportLocation(Loc, PLoc, ModuleName, SM);
292}
293
294/// \brief Emit the module build stack, for cases where a module is (re-)built
295/// on demand.
296void DiagnosticRenderer::emitModuleBuildStack(const SourceManager &SM) {
297  ModuleBuildStack Stack = SM.getModuleBuildStack();
298  for (unsigned I = 0, N = Stack.size(); I != N; ++I) {
299    const SourceManager &CurSM = Stack[I].second.getManager();
300    SourceLocation CurLoc = Stack[I].second;
301    emitBuildingModuleLocation(CurLoc,
302                               CurSM.getPresumedLoc(CurLoc,
303                                                    DiagOpts->ShowPresumedLoc),
304                               Stack[I].first,
305                               CurSM);
306  }
307}
308
309// Helper function to fix up source ranges.  It takes in an array of ranges,
310// and outputs an array of ranges where we want to draw the range highlighting
311// around the location specified by CaretLoc.
312//
313// To find locations which correspond to the caret, we crawl the macro caller
314// chain for the beginning and end of each range.  If the caret location
315// is in a macro expansion, we search each chain for a location
316// in the same expansion as the caret; otherwise, we crawl to the top of
317// each chain. Two locations are part of the same macro expansion
318// iff the FileID is the same.
319static void mapDiagnosticRanges(
320    SourceLocation CaretLoc,
321    ArrayRef<CharSourceRange> Ranges,
322    SmallVectorImpl<CharSourceRange> &SpellingRanges,
323    const SourceManager *SM) {
324  FileID CaretLocFileID = SM->getFileID(CaretLoc);
325
326  for (ArrayRef<CharSourceRange>::const_iterator I = Ranges.begin(),
327       E = Ranges.end();
328       I != E; ++I) {
329    SourceLocation Begin = I->getBegin(), End = I->getEnd();
330    bool IsTokenRange = I->isTokenRange();
331
332    FileID BeginFileID = SM->getFileID(Begin);
333    FileID EndFileID = SM->getFileID(End);
334
335    // Find the common parent for the beginning and end of the range.
336
337    // First, crawl the expansion chain for the beginning of the range.
338    llvm::SmallDenseMap<FileID, SourceLocation> BeginLocsMap;
339    while (Begin.isMacroID() && BeginFileID != EndFileID) {
340      BeginLocsMap[BeginFileID] = Begin;
341      Begin = SM->getImmediateExpansionRange(Begin).first;
342      BeginFileID = SM->getFileID(Begin);
343    }
344
345    // Then, crawl the expansion chain for the end of the range.
346    if (BeginFileID != EndFileID) {
347      while (End.isMacroID() && !BeginLocsMap.count(EndFileID)) {
348        End = SM->getImmediateExpansionRange(End).second;
349        EndFileID = SM->getFileID(End);
350      }
351      if (End.isMacroID()) {
352        Begin = BeginLocsMap[EndFileID];
353        BeginFileID = EndFileID;
354      }
355    }
356
357    while (Begin.isMacroID() && BeginFileID != CaretLocFileID) {
358      if (SM->isMacroArgExpansion(Begin)) {
359        Begin = SM->getImmediateSpellingLoc(Begin);
360        End = SM->getImmediateSpellingLoc(End);
361      } else {
362        Begin = SM->getImmediateExpansionRange(Begin).first;
363        End = SM->getImmediateExpansionRange(End).second;
364      }
365      BeginFileID = SM->getFileID(Begin);
366      if (BeginFileID != SM->getFileID(End)) {
367        // FIXME: Ugly hack to stop a crash; this code is making bad
368        // assumptions and it's too complicated for me to reason
369        // about.
370        Begin = End = SourceLocation();
371        break;
372      }
373    }
374
375    // Return the spelling location of the beginning and end of the range.
376    Begin = SM->getSpellingLoc(Begin);
377    End = SM->getSpellingLoc(End);
378    SpellingRanges.push_back(CharSourceRange(SourceRange(Begin, End),
379                                             IsTokenRange));
380  }
381}
382
383void DiagnosticRenderer::emitCaret(SourceLocation Loc,
384                                   DiagnosticsEngine::Level Level,
385                                   ArrayRef<CharSourceRange> Ranges,
386                                   ArrayRef<FixItHint> Hints,
387                                   const SourceManager &SM) {
388  SmallVector<CharSourceRange, 4> SpellingRanges;
389  mapDiagnosticRanges(Loc, Ranges, SpellingRanges, &SM);
390  emitCodeContext(Loc, Level, SpellingRanges, Hints, SM);
391}
392
393/// \brief Recursively emit notes for each macro expansion and caret
394/// diagnostics where appropriate.
395///
396/// Walks up the macro expansion stack printing expansion notes, the code
397/// snippet, caret, underlines and FixItHint display as appropriate at each
398/// level.
399///
400/// \param Loc The location for this caret.
401/// \param Level The diagnostic level currently being emitted.
402/// \param Ranges The underlined ranges for this code snippet.
403/// \param Hints The FixIt hints active for this diagnostic.
404/// \param MacroSkipEnd The depth to stop skipping macro expansions.
405/// \param OnMacroInst The current depth of the macro expansion stack.
406void DiagnosticRenderer::emitMacroExpansions(SourceLocation Loc,
407                                             DiagnosticsEngine::Level Level,
408                                             ArrayRef<CharSourceRange> Ranges,
409                                             ArrayRef<FixItHint> Hints,
410                                             const SourceManager &SM,
411                                             unsigned &MacroDepth,
412                                             unsigned OnMacroInst) {
413  assert(!Loc.isInvalid() && "must have a valid source location here");
414
415  // Walk up to the caller of this macro, and produce a backtrace down to there.
416  SourceLocation OneLevelUp = SM.getImmediateMacroCallerLoc(Loc);
417  if (OneLevelUp.isMacroID())
418    emitMacroExpansions(OneLevelUp, Level, Ranges, Hints, SM,
419                        MacroDepth, OnMacroInst + 1);
420  else
421    MacroDepth = OnMacroInst + 1;
422
423  unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
424  if (MacroDepth > DiagOpts->MacroBacktraceLimit &&
425      DiagOpts->MacroBacktraceLimit != 0) {
426    MacroSkipStart = DiagOpts->MacroBacktraceLimit / 2 +
427    DiagOpts->MacroBacktraceLimit % 2;
428    MacroSkipEnd = MacroDepth - DiagOpts->MacroBacktraceLimit / 2;
429  }
430
431  // Whether to suppress printing this macro expansion.
432  bool Suppressed = (OnMacroInst >= MacroSkipStart &&
433                     OnMacroInst < MacroSkipEnd);
434
435  if (Suppressed) {
436    // Tell the user that we've skipped contexts.
437    if (OnMacroInst == MacroSkipStart) {
438      SmallString<200> MessageStorage;
439      llvm::raw_svector_ostream Message(MessageStorage);
440      Message << "(skipping " << (MacroSkipEnd - MacroSkipStart)
441              << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
442                 "see all)";
443      emitBasicNote(Message.str());
444    }
445    return;
446  }
447
448  // Find the spelling location for the macro definition. We must use the
449  // spelling location here to avoid emitting a macro bactrace for the note.
450  SourceLocation SpellingLoc = Loc;
451  // If this is the expansion of a macro argument, point the caret at the
452  // use of the argument in the definition of the macro, not the expansion.
453  if (SM.isMacroArgExpansion(Loc))
454    SpellingLoc = SM.getImmediateExpansionRange(Loc).first;
455  SpellingLoc = SM.getSpellingLoc(SpellingLoc);
456
457  // Map the ranges into the FileID of the diagnostic location.
458  SmallVector<CharSourceRange, 4> SpellingRanges;
459  mapDiagnosticRanges(Loc, Ranges, SpellingRanges, &SM);
460
461  SmallString<100> MessageStorage;
462  llvm::raw_svector_ostream Message(MessageStorage);
463  StringRef MacroName = getImmediateMacroName(Loc, SM, LangOpts);
464  if (MacroName.empty())
465    Message << "expanded from here";
466  else
467    Message << "expanded from macro '" << MacroName << "'";
468  emitDiagnostic(SpellingLoc, DiagnosticsEngine::Note,
469                 Message.str(),
470                 SpellingRanges, ArrayRef<FixItHint>(), &SM);
471}
472
473DiagnosticNoteRenderer::~DiagnosticNoteRenderer() {}
474
475void DiagnosticNoteRenderer::emitIncludeLocation(SourceLocation Loc,
476                                                 PresumedLoc PLoc,
477                                                 const SourceManager &SM) {
478  // Generate a note indicating the include location.
479  SmallString<200> MessageStorage;
480  llvm::raw_svector_ostream Message(MessageStorage);
481  Message << "in file included from " << PLoc.getFilename() << ':'
482          << PLoc.getLine() << ":";
483  emitNote(Loc, Message.str(), &SM);
484}
485
486void DiagnosticNoteRenderer::emitImportLocation(SourceLocation Loc,
487                                                PresumedLoc PLoc,
488                                                StringRef ModuleName,
489                                                const SourceManager &SM) {
490  // Generate a note indicating the include location.
491  SmallString<200> MessageStorage;
492  llvm::raw_svector_ostream Message(MessageStorage);
493  Message << "in module '" << ModuleName << "' imported from "
494          << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
495  emitNote(Loc, Message.str(), &SM);
496}
497
498void
499DiagnosticNoteRenderer::emitBuildingModuleLocation(SourceLocation Loc,
500                                                   PresumedLoc PLoc,
501                                                   StringRef ModuleName,
502                                                   const SourceManager &SM) {
503  // Generate a note indicating the include location.
504  SmallString<200> MessageStorage;
505  llvm::raw_svector_ostream Message(MessageStorage);
506  Message << "while building module '" << ModuleName << "' imported from "
507          << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
508  emitNote(Loc, Message.str(), &SM);
509}
510
511
512void DiagnosticNoteRenderer::emitBasicNote(StringRef Message) {
513  emitNote(SourceLocation(), Message, 0);
514}
515