DiagnosticRenderer.cpp revision 243830 
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);
132
133    // First, if this diagnostic is not in the main file, print out the
134    // "included from" lines.
135    emitIncludeStack(PLoc.getIncludeLoc(), 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 Level The diagnostic level of the message this stack pertains to.
188/// \param Loc   The include location of the current file (not the diagnostic
189///              location).
190void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
191                                          DiagnosticsEngine::Level Level,
192                                          const SourceManager &SM) {
193  // Skip redundant include stacks altogether.
194  if (LastIncludeLoc == Loc)
195    return;
196  LastIncludeLoc = Loc;
197
198  if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
199    return;
200
201  emitIncludeStackRecursively(Loc, SM);
202}
203
204/// \brief Helper to recursivly walk up the include stack and print each layer
205/// on the way back down.
206void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc,
207                                                     const SourceManager &SM) {
208  if (Loc.isInvalid())
209    return;
210
211  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
212  if (PLoc.isInvalid())
213    return;
214
215  // Emit the other include frames first.
216  emitIncludeStackRecursively(PLoc.getIncludeLoc(), SM);
217
218  // Emit the inclusion text/note.
219  emitIncludeLocation(Loc, PLoc, SM);
220}
221
222// Helper function to fix up source ranges.  It takes in an array of ranges,
223// and outputs an array of ranges where we want to draw the range highlighting
224// around the location specified by CaretLoc.
225//
226// To find locations which correspond to the caret, we crawl the macro caller
227// chain for the beginning and end of each range.  If the caret location
228// is in a macro expansion, we search each chain for a location
229// in the same expansion as the caret; otherwise, we crawl to the top of
230// each chain. Two locations are part of the same macro expansion
231// iff the FileID is the same.
232static void mapDiagnosticRanges(
233    SourceLocation CaretLoc,
234    const SmallVectorImpl<CharSourceRange>& Ranges,
235    SmallVectorImpl<CharSourceRange>& SpellingRanges,
236    const SourceManager *SM) {
237  FileID CaretLocFileID = SM->getFileID(CaretLoc);
238
239  for (SmallVectorImpl<CharSourceRange>::const_iterator I = Ranges.begin(),
240       E = Ranges.end();
241       I != E; ++I) {
242    SourceLocation Begin = I->getBegin(), End = I->getEnd();
243    bool IsTokenRange = I->isTokenRange();
244
245    // Search the macro caller chain for the beginning of the range.
246    while (Begin.isMacroID() && SM->getFileID(Begin) != CaretLocFileID)
247      Begin = SM->getImmediateMacroCallerLoc(Begin);
248
249    // Search the macro caller chain for the beginning of the range.
250    while (End.isMacroID() && SM->getFileID(End) != CaretLocFileID) {
251      // The computation of the next End is an inlined version of
252      // getImmediateMacroCallerLoc, except it chooses the end of an
253      // expansion range.
254      if (SM->isMacroArgExpansion(End)) {
255        End = SM->getImmediateSpellingLoc(End);
256      } else {
257        End = SM->getImmediateExpansionRange(End).second;
258      }
259    }
260
261    // Return the spelling location of the beginning and end of the range.
262    Begin = SM->getSpellingLoc(Begin);
263    End = SM->getSpellingLoc(End);
264    SpellingRanges.push_back(CharSourceRange(SourceRange(Begin, End),
265                                             IsTokenRange));
266  }
267}
268
269/// \brief Recursively emit notes for each macro expansion and caret
270/// diagnostics where appropriate.
271///
272/// Walks up the macro expansion stack printing expansion notes, the code
273/// snippet, caret, underlines and FixItHint display as appropriate at each
274/// level.
275///
276/// \param Loc The location for this caret.
277/// \param Level The diagnostic level currently being emitted.
278/// \param Ranges The underlined ranges for this code snippet.
279/// \param Hints The FixIt hints active for this diagnostic.
280/// \param MacroSkipEnd The depth to stop skipping macro expansions.
281/// \param OnMacroInst The current depth of the macro expansion stack.
282void DiagnosticRenderer::emitMacroExpansionsAndCarets(
283       SourceLocation Loc,
284       DiagnosticsEngine::Level Level,
285       SmallVectorImpl<CharSourceRange>& Ranges,
286       ArrayRef<FixItHint> Hints,
287       const SourceManager &SM,
288       unsigned &MacroDepth,
289       unsigned OnMacroInst)
290{
291  assert(!Loc.isInvalid() && "must have a valid source location here");
292
293  // If this is a file source location, directly emit the source snippet and
294  // caret line. Also record the macro depth reached.
295  if (Loc.isFileID()) {
296    // Map the ranges.
297    SmallVector<CharSourceRange, 4> SpellingRanges;
298    mapDiagnosticRanges(Loc, Ranges, SpellingRanges, &SM);
299
300    assert(MacroDepth == 0 && "We shouldn't hit a leaf node twice!");
301    MacroDepth = OnMacroInst;
302    emitCodeContext(Loc, Level, SpellingRanges, Hints, SM);
303    return;
304  }
305  // Otherwise recurse through each macro expansion layer.
306
307  // When processing macros, skip over the expansions leading up to
308  // a macro argument, and trace the argument's expansion stack instead.
309  Loc = SM.skipToMacroArgExpansion(Loc);
310
311  SourceLocation OneLevelUp = SM.getImmediateMacroCallerLoc(Loc);
312
313  emitMacroExpansionsAndCarets(OneLevelUp, Level, Ranges, Hints, SM, MacroDepth,
314                               OnMacroInst + 1);
315
316  // Save the original location so we can find the spelling of the macro call.
317  SourceLocation MacroLoc = Loc;
318
319  // Map the location.
320  Loc = SM.getImmediateMacroCalleeLoc(Loc);
321
322  unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
323  if (MacroDepth > DiagOpts->MacroBacktraceLimit &&
324      DiagOpts->MacroBacktraceLimit != 0) {
325    MacroSkipStart = DiagOpts->MacroBacktraceLimit / 2 +
326    DiagOpts->MacroBacktraceLimit % 2;
327    MacroSkipEnd = MacroDepth - DiagOpts->MacroBacktraceLimit / 2;
328  }
329
330  // Whether to suppress printing this macro expansion.
331  bool Suppressed = (OnMacroInst >= MacroSkipStart &&
332                     OnMacroInst < MacroSkipEnd);
333
334  if (Suppressed) {
335    // Tell the user that we've skipped contexts.
336    if (OnMacroInst == MacroSkipStart) {
337      SmallString<200> MessageStorage;
338      llvm::raw_svector_ostream Message(MessageStorage);
339      Message << "(skipping " << (MacroSkipEnd - MacroSkipStart)
340              << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
341                 "see all)";
342      emitBasicNote(Message.str());
343    }
344    return;
345  }
346
347  // Map the ranges.
348  SmallVector<CharSourceRange, 4> SpellingRanges;
349  mapDiagnosticRanges(MacroLoc, Ranges, SpellingRanges, &SM);
350
351  SmallString<100> MessageStorage;
352  llvm::raw_svector_ostream Message(MessageStorage);
353  Message << "expanded from macro '"
354          << getImmediateMacroName(MacroLoc, SM, LangOpts) << "'";
355  emitDiagnostic(SM.getSpellingLoc(Loc), DiagnosticsEngine::Note,
356                 Message.str(),
357                 SpellingRanges, ArrayRef<FixItHint>(), &SM);
358}
359
360DiagnosticNoteRenderer::~DiagnosticNoteRenderer() {}
361
362void DiagnosticNoteRenderer::emitIncludeLocation(SourceLocation Loc,
363                                                 PresumedLoc PLoc,
364                                                 const SourceManager &SM) {
365  // Generate a note indicating the include location.
366  SmallString<200> MessageStorage;
367  llvm::raw_svector_ostream Message(MessageStorage);
368  Message << "in file included from " << PLoc.getFilename() << ':'
369          << PLoc.getLine() << ":";
370  emitNote(Loc, Message.str(), &SM);
371}
372
373void DiagnosticNoteRenderer::emitBasicNote(StringRef Message) {
374  emitNote(SourceLocation(), Message, 0);
375}
376