DiagnosticRenderer.cpp revision 4565e487531c7bf6d348dbe9f5529784966fc7ae 
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/Lex/Lexer.h"
15#include "clang/Edit/EditedSource.h"
16#include "clang/Edit/Commit.h"
17#include "clang/Edit/EditsReceiver.h"
18#include "llvm/Support/MemoryBuffer.h"
19#include "llvm/Support/raw_ostream.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/ADT/SmallSet.h"
22#include "llvm/ADT/SmallString.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   // Find the spelling location of the start of the non-argument expansion
51   // range. This is where the macro name was spelled in order to begin
52   // expanding this macro.
53   Loc = SM.getSpellingLoc(SM.getImmediateExpansionRange(Loc).first);
54
55   // Dig out the buffer where the macro name was spelled and the extents of the
56   // name so that we can render it into the expansion note.
57   std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
58   unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
59   StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
60   return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
61}
62
63DiagnosticRenderer::DiagnosticRenderer(const LangOptions &LangOpts,
64                                       DiagnosticOptions *DiagOpts)
65  : LangOpts(LangOpts), DiagOpts(DiagOpts), LastLevel() {}
66
67DiagnosticRenderer::~DiagnosticRenderer() {}
68
69namespace {
70
71class FixitReceiver : public edit::EditsReceiver {
72  SmallVectorImpl<FixItHint> &MergedFixits;
73
74public:
75  FixitReceiver(SmallVectorImpl<FixItHint> &MergedFixits)
76    : MergedFixits(MergedFixits) { }
77  virtual void insert(SourceLocation loc, StringRef text) {
78    MergedFixits.push_back(FixItHint::CreateInsertion(loc, text));
79  }
80  virtual void replace(CharSourceRange range, StringRef text) {
81    MergedFixits.push_back(FixItHint::CreateReplacement(range, text));
82  }
83};
84
85}
86
87static void mergeFixits(ArrayRef<FixItHint> FixItHints,
88                        const SourceManager &SM, const LangOptions &LangOpts,
89                        SmallVectorImpl<FixItHint> &MergedFixits) {
90  edit::Commit commit(SM, LangOpts);
91  for (ArrayRef<FixItHint>::const_iterator
92         I = FixItHints.begin(), E = FixItHints.end(); I != E; ++I) {
93    const FixItHint &Hint = *I;
94    if (Hint.CodeToInsert.empty()) {
95      if (Hint.InsertFromRange.isValid())
96        commit.insertFromRange(Hint.RemoveRange.getBegin(),
97                           Hint.InsertFromRange, /*afterToken=*/false,
98                           Hint.BeforePreviousInsertions);
99      else
100        commit.remove(Hint.RemoveRange);
101    } else {
102      if (Hint.RemoveRange.isTokenRange() ||
103          Hint.RemoveRange.getBegin() != Hint.RemoveRange.getEnd())
104        commit.replace(Hint.RemoveRange, Hint.CodeToInsert);
105      else
106        commit.insert(Hint.RemoveRange.getBegin(), Hint.CodeToInsert,
107                    /*afterToken=*/false, Hint.BeforePreviousInsertions);
108    }
109  }
110
111  edit::EditedSource Editor(SM, LangOpts);
112  if (Editor.commit(commit)) {
113    FixitReceiver Rec(MergedFixits);
114    Editor.applyRewrites(Rec);
115  }
116}
117
118void DiagnosticRenderer::emitDiagnostic(SourceLocation Loc,
119                                        DiagnosticsEngine::Level Level,
120                                        StringRef Message,
121                                        ArrayRef<CharSourceRange> Ranges,
122                                        ArrayRef<FixItHint> FixItHints,
123                                        const SourceManager *SM,
124                                        DiagOrStoredDiag D) {
125  assert(SM || Loc.isInvalid());
126
127  beginDiagnostic(D, Level);
128
129  PresumedLoc PLoc;
130  if (Loc.isValid()) {
131    PLoc = SM->getPresumedLocForDisplay(Loc, DiagOpts->ShowPresumedLoc);
132
133    // First, if this diagnostic is not in the main file, print out the
134    // "included from" lines.
135    emitIncludeStack(Loc, PLoc, Level, *SM);
136  }
137
138  // Next, emit the actual diagnostic message.
139  emitDiagnosticMessage(Loc, PLoc, Level, Message, Ranges, SM, D);
140
141  // Only recurse if we have a valid location.
142  if (Loc.isValid()) {
143    // Get the ranges into a local array we can hack on.
144    SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
145                                                   Ranges.end());
146
147    llvm::SmallVector<FixItHint, 8> MergedFixits;
148    if (!FixItHints.empty()) {
149      mergeFixits(FixItHints, *SM, LangOpts, MergedFixits);
150      FixItHints = MergedFixits;
151    }
152
153    for (ArrayRef<FixItHint>::const_iterator I = FixItHints.begin(),
154         E = FixItHints.end();
155         I != E; ++I)
156      if (I->RemoveRange.isValid())
157        MutableRanges.push_back(I->RemoveRange);
158
159    unsigned MacroDepth = 0;
160    emitMacroExpansionsAndCarets(Loc, Level, MutableRanges, FixItHints, *SM,
161                                 MacroDepth);
162  }
163
164  LastLoc = Loc;
165  LastLevel = Level;
166
167  endDiagnostic(D, Level);
168}
169
170
171void DiagnosticRenderer::emitStoredDiagnostic(StoredDiagnostic &Diag) {
172  emitDiagnostic(Diag.getLocation(), Diag.getLevel(), Diag.getMessage(),
173                 Diag.getRanges(), Diag.getFixIts(),
174                 Diag.getLocation().isValid() ? &Diag.getLocation().getManager()
175                                              : 0,
176                 &Diag);
177}
178
179/// \brief Prints an include stack when appropriate for a particular
180/// diagnostic level and location.
181///
182/// This routine handles all the logic of suppressing particular include
183/// stacks (such as those for notes) and duplicate include stacks when
184/// repeated warnings occur within the same file. It also handles the logic
185/// of customizing the formatting and display of the include stack.
186///
187/// \param Loc   The diagnostic location.
188/// \param PLoc  The presumed location of the diagnostic location.
189/// \param Level The diagnostic level of the message this stack pertains to.
190void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
191                                          PresumedLoc PLoc,
192                                          DiagnosticsEngine::Level Level,
193                                          const SourceManager &SM) {
194  SourceLocation IncludeLoc = PLoc.getIncludeLoc();
195
196  // Skip redundant include stacks altogether.
197  if (LastIncludeLoc == IncludeLoc)
198    return;
199
200  LastIncludeLoc = IncludeLoc;
201
202  if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
203    return;
204
205  if (IncludeLoc.isValid())
206    emitIncludeStackRecursively(IncludeLoc, SM);
207  else {
208    emitModuleBuildStack(SM);
209    emitImportStack(Loc, SM);
210  }
211}
212
213/// \brief Helper to recursivly walk up the include stack and print each layer
214/// on the way back down.
215void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc,
216                                                     const SourceManager &SM) {
217  if (Loc.isInvalid()) {
218    emitModuleBuildStack(SM);
219    return;
220  }
221
222  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
223  if (PLoc.isInvalid())
224    return;
225
226  // If this source location was imported from a module, print the module
227  // import stack rather than the
228  // FIXME: We want submodule granularity here.
229  std::pair<SourceLocation, StringRef> Imported = SM.getModuleImportLoc(Loc);
230  if (Imported.first.isValid()) {
231    // This location was imported by a module. Emit the module import stack.
232    emitImportStackRecursively(Imported.first, Imported.second, SM);
233    return;
234  }
235
236  // Emit the other include frames first.
237  emitIncludeStackRecursively(PLoc.getIncludeLoc(), SM);
238
239  // Emit the inclusion text/note.
240  emitIncludeLocation(Loc, PLoc, SM);
241}
242
243/// \brief Emit the module import stack associated with the current location.
244void DiagnosticRenderer::emitImportStack(SourceLocation Loc,
245                                         const SourceManager &SM) {
246  if (Loc.isInvalid()) {
247    emitModuleBuildStack(SM);
248    return;
249  }
250
251  std::pair<SourceLocation, StringRef> NextImportLoc
252    = SM.getModuleImportLoc(Loc);
253  emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second, SM);
254}
255
256/// \brief Helper to recursivly walk up the import stack and print each layer
257/// on the way back down.
258void DiagnosticRenderer::emitImportStackRecursively(SourceLocation Loc,
259                                                    StringRef ModuleName,
260                                                    const SourceManager &SM) {
261  if (Loc.isInvalid()) {
262    return;
263  }
264
265  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
266  if (PLoc.isInvalid())
267    return;
268
269  // Emit the other import frames first.
270  std::pair<SourceLocation, StringRef> NextImportLoc
271    = SM.getModuleImportLoc(Loc);
272  emitImportStackRecursively(NextImportLoc.first, NextImportLoc.second, SM);
273
274  // Emit the inclusion text/note.
275  emitImportLocation(Loc, PLoc, ModuleName, SM);
276}
277
278/// \brief Emit the module build stack, for cases where a module is (re-)built
279/// on demand.
280void DiagnosticRenderer::emitModuleBuildStack(const SourceManager &SM) {
281  ModuleBuildStack Stack = SM.getModuleBuildStack();
282  for (unsigned I = 0, N = Stack.size(); I != N; ++I) {
283    const SourceManager &CurSM = Stack[I].second.getManager();
284    SourceLocation CurLoc = Stack[I].second;
285    emitBuildingModuleLocation(CurLoc,
286                               CurSM.getPresumedLoc(CurLoc,
287                                                    DiagOpts->ShowPresumedLoc),
288                               Stack[I].first,
289                               CurSM);
290  }
291}
292
293// Helper function to fix up source ranges.  It takes in an array of ranges,
294// and outputs an array of ranges where we want to draw the range highlighting
295// around the location specified by CaretLoc.
296//
297// To find locations which correspond to the caret, we crawl the macro caller
298// chain for the beginning and end of each range.  If the caret location
299// is in a macro expansion, we search each chain for a location
300// in the same expansion as the caret; otherwise, we crawl to the top of
301// each chain. Two locations are part of the same macro expansion
302// iff the FileID is the same.
303static void mapDiagnosticRanges(
304    SourceLocation CaretLoc,
305    const SmallVectorImpl<CharSourceRange>& Ranges,
306    SmallVectorImpl<CharSourceRange>& SpellingRanges,
307    const SourceManager *SM) {
308  FileID CaretLocFileID = SM->getFileID(CaretLoc);
309
310  for (SmallVectorImpl<CharSourceRange>::const_iterator I = Ranges.begin(),
311       E = Ranges.end();
312       I != E; ++I) {
313    SourceLocation Begin = I->getBegin(), End = I->getEnd();
314    bool IsTokenRange = I->isTokenRange();
315
316    FileID BeginFileID = SM->getFileID(Begin);
317    FileID EndFileID = SM->getFileID(End);
318
319    // Find the common parent for the beginning and end of the range.
320
321    // First, crawl the expansion chain for the beginning of the range.
322    llvm::SmallDenseMap<FileID, SourceLocation> BeginLocsMap;
323    while (Begin.isMacroID() && BeginFileID != EndFileID) {
324      BeginLocsMap[BeginFileID] = Begin;
325      Begin = SM->getImmediateExpansionRange(Begin).first;
326      BeginFileID = SM->getFileID(Begin);
327    }
328
329    // Then, crawl the expansion chain for the end of the range.
330    if (BeginFileID != EndFileID) {
331      while (End.isMacroID() && !BeginLocsMap.count(EndFileID)) {
332        End = SM->getImmediateExpansionRange(End).second;
333        EndFileID = SM->getFileID(End);
334      }
335      if (End.isMacroID()) {
336        Begin = BeginLocsMap[EndFileID];
337        BeginFileID = EndFileID;
338      }
339    }
340
341    while (Begin.isMacroID() && BeginFileID != CaretLocFileID) {
342      if (SM->isMacroArgExpansion(Begin)) {
343        Begin = SM->getImmediateSpellingLoc(Begin);
344        End = SM->getImmediateSpellingLoc(End);
345      } else {
346        Begin = SM->getImmediateExpansionRange(Begin).first;
347        End = SM->getImmediateExpansionRange(End).second;
348      }
349      BeginFileID = SM->getFileID(Begin);
350    }
351
352    // Return the spelling location of the beginning and end of the range.
353    Begin = SM->getSpellingLoc(Begin);
354    End = SM->getSpellingLoc(End);
355    SpellingRanges.push_back(CharSourceRange(SourceRange(Begin, End),
356                                             IsTokenRange));
357  }
358}
359
360/// \brief Recursively emit notes for each macro expansion and caret
361/// diagnostics where appropriate.
362///
363/// Walks up the macro expansion stack printing expansion notes, the code
364/// snippet, caret, underlines and FixItHint display as appropriate at each
365/// level.
366///
367/// \param Loc The location for this caret.
368/// \param Level The diagnostic level currently being emitted.
369/// \param Ranges The underlined ranges for this code snippet.
370/// \param Hints The FixIt hints active for this diagnostic.
371/// \param MacroSkipEnd The depth to stop skipping macro expansions.
372/// \param OnMacroInst The current depth of the macro expansion stack.
373void DiagnosticRenderer::emitMacroExpansionsAndCarets(
374       SourceLocation Loc,
375       DiagnosticsEngine::Level Level,
376       SmallVectorImpl<CharSourceRange>& Ranges,
377       ArrayRef<FixItHint> Hints,
378       const SourceManager &SM,
379       unsigned &MacroDepth,
380       unsigned OnMacroInst)
381{
382  assert(!Loc.isInvalid() && "must have a valid source location here");
383
384  // If this is a file source location, directly emit the source snippet and
385  // caret line. Also record the macro depth reached.
386  if (Loc.isFileID()) {
387    // Map the ranges.
388    SmallVector<CharSourceRange, 4> SpellingRanges;
389    mapDiagnosticRanges(Loc, Ranges, SpellingRanges, &SM);
390
391    assert(MacroDepth == 0 && "We shouldn't hit a leaf node twice!");
392    MacroDepth = OnMacroInst;
393    emitCodeContext(Loc, Level, SpellingRanges, Hints, SM);
394    return;
395  }
396  // Otherwise recurse through each macro expansion layer.
397
398  // When processing macros, skip over the expansions leading up to
399  // a macro argument, and trace the argument's expansion stack instead.
400  Loc = SM.skipToMacroArgExpansion(Loc);
401
402  SourceLocation OneLevelUp = SM.getImmediateMacroCallerLoc(Loc);
403
404  emitMacroExpansionsAndCarets(OneLevelUp, Level, Ranges, Hints, SM, MacroDepth,
405                               OnMacroInst + 1);
406
407  // Save the original location so we can find the spelling of the macro call.
408  SourceLocation MacroLoc = Loc;
409
410  // Map the location.
411  Loc = SM.getImmediateMacroCalleeLoc(Loc);
412
413  unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
414  if (MacroDepth > DiagOpts->MacroBacktraceLimit &&
415      DiagOpts->MacroBacktraceLimit != 0) {
416    MacroSkipStart = DiagOpts->MacroBacktraceLimit / 2 +
417    DiagOpts->MacroBacktraceLimit % 2;
418    MacroSkipEnd = MacroDepth - DiagOpts->MacroBacktraceLimit / 2;
419  }
420
421  // Whether to suppress printing this macro expansion.
422  bool Suppressed = (OnMacroInst >= MacroSkipStart &&
423                     OnMacroInst < MacroSkipEnd);
424
425  if (Suppressed) {
426    // Tell the user that we've skipped contexts.
427    if (OnMacroInst == MacroSkipStart) {
428      SmallString<200> MessageStorage;
429      llvm::raw_svector_ostream Message(MessageStorage);
430      Message << "(skipping " << (MacroSkipEnd - MacroSkipStart)
431              << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
432                 "see all)";
433      emitBasicNote(Message.str());
434    }
435    return;
436  }
437
438  // Map the ranges.
439  SmallVector<CharSourceRange, 4> SpellingRanges;
440  mapDiagnosticRanges(MacroLoc, Ranges, SpellingRanges, &SM);
441
442  SmallString<100> MessageStorage;
443  llvm::raw_svector_ostream Message(MessageStorage);
444  Message << "expanded from macro '"
445          << getImmediateMacroName(MacroLoc, SM, LangOpts) << "'";
446  emitDiagnostic(SM.getSpellingLoc(Loc), DiagnosticsEngine::Note,
447                 Message.str(),
448                 SpellingRanges, ArrayRef<FixItHint>(), &SM);
449}
450
451DiagnosticNoteRenderer::~DiagnosticNoteRenderer() {}
452
453void DiagnosticNoteRenderer::emitIncludeLocation(SourceLocation Loc,
454                                                 PresumedLoc PLoc,
455                                                 const SourceManager &SM) {
456  // Generate a note indicating the include location.
457  SmallString<200> MessageStorage;
458  llvm::raw_svector_ostream Message(MessageStorage);
459  Message << "in file included from " << PLoc.getFilename() << ':'
460          << PLoc.getLine() << ":";
461  emitNote(Loc, Message.str(), &SM);
462}
463
464void DiagnosticNoteRenderer::emitImportLocation(SourceLocation Loc,
465                                                PresumedLoc PLoc,
466                                                StringRef ModuleName,
467                                                const SourceManager &SM) {
468  // Generate a note indicating the include location.
469  SmallString<200> MessageStorage;
470  llvm::raw_svector_ostream Message(MessageStorage);
471  Message << "in module '" << ModuleName << "' imported from "
472          << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
473  emitNote(Loc, Message.str(), &SM);
474}
475
476void
477DiagnosticNoteRenderer::emitBuildingModuleLocation(SourceLocation Loc,
478                                                   PresumedLoc PLoc,
479                                                   StringRef ModuleName,
480                                                   const SourceManager &SM) {
481  // Generate a note indicating the include location.
482  SmallString<200> MessageStorage;
483  llvm::raw_svector_ostream Message(MessageStorage);
484  Message << "while building module '" << ModuleName << "' imported from "
485          << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
486  emitNote(Loc, Message.str(), &SM);
487}
488
489
490void DiagnosticNoteRenderer::emitBasicNote(StringRef Message) {
491  emitNote(SourceLocation(), Message, 0);
492}
493