clang  11.0.0git
HTMLDiagnostics.cpp
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1 //===- HTMLDiagnostics.cpp - HTML Diagnostics for Paths -------------------===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the HTMLDiagnostics object.
10 //
11 //===----------------------------------------------------------------------===//
12 
14 #include "clang/AST/Decl.h"
15 #include "clang/AST/DeclBase.h"
16 #include "clang/AST/Stmt.h"
18 #include "clang/Basic/LLVM.h"
21 #include "clang/Lex/Lexer.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Lex/Token.h"
29 #include "llvm/ADT/ArrayRef.h"
30 #include "llvm/ADT/SmallString.h"
31 #include "llvm/ADT/StringRef.h"
32 #include "llvm/ADT/iterator_range.h"
33 #include "llvm/Support/Casting.h"
34 #include "llvm/Support/Errc.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/FileSystem.h"
37 #include "llvm/Support/MemoryBuffer.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include <algorithm>
41 #include <cassert>
42 #include <map>
43 #include <memory>
44 #include <set>
45 #include <sstream>
46 #include <string>
47 #include <system_error>
48 #include <utility>
49 #include <vector>
50 
51 using namespace clang;
52 using namespace ento;
53 
54 //===----------------------------------------------------------------------===//
55 // Boilerplate.
56 //===----------------------------------------------------------------------===//
57 
58 namespace {
59 
60 class HTMLDiagnostics : public PathDiagnosticConsumer {
61  std::string Directory;
62  bool createdDir = false;
63  bool noDir = false;
64  const Preprocessor &PP;
65  AnalyzerOptions &AnalyzerOpts;
66  const bool SupportsCrossFileDiagnostics;
67 
68 public:
69  HTMLDiagnostics(AnalyzerOptions &AnalyzerOpts, const std::string &OutputDir,
70  const Preprocessor &pp, bool supportsMultipleFiles)
71  : Directory(OutputDir), PP(pp), AnalyzerOpts(AnalyzerOpts),
72  SupportsCrossFileDiagnostics(supportsMultipleFiles) {}
73 
74  ~HTMLDiagnostics() override { FlushDiagnostics(nullptr); }
75 
76  void FlushDiagnosticsImpl(std::vector<const PathDiagnostic *> &Diags,
77  FilesMade *filesMade) override;
78 
79  StringRef getName() const override {
80  return "HTMLDiagnostics";
81  }
82 
83  bool supportsCrossFileDiagnostics() const override {
84  return SupportsCrossFileDiagnostics;
85  }
86 
87  unsigned ProcessMacroPiece(raw_ostream &os,
88  const PathDiagnosticMacroPiece& P,
89  unsigned num);
90 
91  void HandlePiece(Rewriter &R, FileID BugFileID, const PathDiagnosticPiece &P,
92  const std::vector<SourceRange> &PopUpRanges, unsigned num,
93  unsigned max);
94 
95  void HighlightRange(Rewriter& R, FileID BugFileID, SourceRange Range,
96  const char *HighlightStart = "<span class=\"mrange\">",
97  const char *HighlightEnd = "</span>");
98 
99  void ReportDiag(const PathDiagnostic& D,
100  FilesMade *filesMade);
101 
102  // Generate the full HTML report
103  std::string GenerateHTML(const PathDiagnostic& D, Rewriter &R,
104  const SourceManager& SMgr, const PathPieces& path,
105  const char *declName);
106 
107  // Add HTML header/footers to file specified by FID
108  void FinalizeHTML(const PathDiagnostic& D, Rewriter &R,
109  const SourceManager& SMgr, const PathPieces& path,
110  FileID FID, const FileEntry *Entry, const char *declName);
111 
112  // Rewrite the file specified by FID with HTML formatting.
113  void RewriteFile(Rewriter &R, const PathPieces& path, FileID FID);
114 
115 
116 private:
117  /// \return Javascript for displaying shortcuts help;
118  StringRef showHelpJavascript();
119 
120  /// \return Javascript for navigating the HTML report using j/k keys.
121  StringRef generateKeyboardNavigationJavascript();
122 
123  /// \return JavaScript for an option to only show relevant lines.
124  std::string showRelevantLinesJavascript(
125  const PathDiagnostic &D, const PathPieces &path);
126 
127  /// Write executed lines from \p D in JSON format into \p os.
128  void dumpCoverageData(const PathDiagnostic &D,
129  const PathPieces &path,
130  llvm::raw_string_ostream &os);
131 };
132 
133 } // namespace
134 
135 void ento::createHTMLDiagnosticConsumer(
136  AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
137  const std::string &OutputDir, const Preprocessor &PP,
139 
140  // FIXME: HTML is currently our default output type, but if the output
141  // directory isn't specified, it acts like if it was in the minimal text
142  // output mode. This doesn't make much sense, we should have the minimal text
143  // as our default. In the case of backward compatibility concerns, this could
144  // be preserved with -analyzer-config-compatibility-mode=true.
145  createTextMinimalPathDiagnosticConsumer(AnalyzerOpts, C, OutputDir, PP, CTU);
146 
147  // TODO: Emit an error here.
148  if (OutputDir.empty())
149  return;
150 
151  C.push_back(new HTMLDiagnostics(AnalyzerOpts, OutputDir, PP, true));
152 }
153 
154 void ento::createHTMLSingleFileDiagnosticConsumer(
155  AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
156  const std::string &OutputDir, const Preprocessor &PP,
158 
159  // TODO: Emit an error here.
160  if (OutputDir.empty())
161  return;
162 
163  C.push_back(new HTMLDiagnostics(AnalyzerOpts, OutputDir, PP, false));
164  createTextMinimalPathDiagnosticConsumer(AnalyzerOpts, C, OutputDir, PP, CTU);
165 }
166 
167 void ento::createPlistHTMLDiagnosticConsumer(
168  AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
169  const std::string &prefix, const Preprocessor &PP,
171  createHTMLDiagnosticConsumer(
172  AnalyzerOpts, C, std::string(llvm::sys::path::parent_path(prefix)), PP,
173  CTU);
174  createPlistMultiFileDiagnosticConsumer(AnalyzerOpts, C, prefix, PP, CTU);
175  createTextMinimalPathDiagnosticConsumer(AnalyzerOpts, C, prefix, PP, CTU);
176 }
177 
178 //===----------------------------------------------------------------------===//
179 // Report processing.
180 //===----------------------------------------------------------------------===//
181 
182 void HTMLDiagnostics::FlushDiagnosticsImpl(
183  std::vector<const PathDiagnostic *> &Diags,
184  FilesMade *filesMade) {
185  for (const auto Diag : Diags)
186  ReportDiag(*Diag, filesMade);
187 }
188 
189 void HTMLDiagnostics::ReportDiag(const PathDiagnostic& D,
190  FilesMade *filesMade) {
191  // Create the HTML directory if it is missing.
192  if (!createdDir) {
193  createdDir = true;
194  if (std::error_code ec = llvm::sys::fs::create_directories(Directory)) {
195  llvm::errs() << "warning: could not create directory '"
196  << Directory << "': " << ec.message() << '\n';
197  noDir = true;
198  return;
199  }
200  }
201 
202  if (noDir)
203  return;
204 
205  // First flatten out the entire path to make it easier to use.
206  PathPieces path = D.path.flatten(/*ShouldFlattenMacros=*/false);
207 
208  // The path as already been prechecked that the path is non-empty.
209  assert(!path.empty());
210  const SourceManager &SMgr = path.front()->getLocation().getManager();
211 
212  // Create a new rewriter to generate HTML.
213  Rewriter R(const_cast<SourceManager&>(SMgr), PP.getLangOpts());
214 
215  // The file for the first path element is considered the main report file, it
216  // will usually be equivalent to SMgr.getMainFileID(); however, it might be a
217  // header when -analyzer-opt-analyze-headers is used.
218  FileID ReportFile = path.front()->getLocation().asLocation().getExpansionLoc().getFileID();
219 
220  // Get the function/method name
221  SmallString<128> declName("unknown");
222  int offsetDecl = 0;
223  if (const Decl *DeclWithIssue = D.getDeclWithIssue()) {
224  if (const auto *ND = dyn_cast<NamedDecl>(DeclWithIssue))
225  declName = ND->getDeclName().getAsString();
226 
227  if (const Stmt *Body = DeclWithIssue->getBody()) {
228  // Retrieve the relative position of the declaration which will be used
229  // for the file name
230  FullSourceLoc L(
231  SMgr.getExpansionLoc(path.back()->getLocation().asLocation()),
232  SMgr);
233  FullSourceLoc FunL(SMgr.getExpansionLoc(Body->getBeginLoc()), SMgr);
234  offsetDecl = L.getExpansionLineNumber() - FunL.getExpansionLineNumber();
235  }
236  }
237 
238  std::string report = GenerateHTML(D, R, SMgr, path, declName.c_str());
239  if (report.empty()) {
240  llvm::errs() << "warning: no diagnostics generated for main file.\n";
241  return;
242  }
243 
244  // Create a path for the target HTML file.
245  int FD;
246  SmallString<128> Model, ResultPath;
247 
248  if (!AnalyzerOpts.ShouldWriteStableReportFilename) {
249  llvm::sys::path::append(Model, Directory, "report-%%%%%%.html");
250  if (std::error_code EC =
251  llvm::sys::fs::make_absolute(Model)) {
252  llvm::errs() << "warning: could not make '" << Model
253  << "' absolute: " << EC.message() << '\n';
254  return;
255  }
256  if (std::error_code EC =
257  llvm::sys::fs::createUniqueFile(Model, FD, ResultPath)) {
258  llvm::errs() << "warning: could not create file in '" << Directory
259  << "': " << EC.message() << '\n';
260  return;
261  }
262  } else {
263  int i = 1;
264  std::error_code EC;
265  do {
266  // Find a filename which is not already used
267  const FileEntry* Entry = SMgr.getFileEntryForID(ReportFile);
268  std::stringstream filename;
269  Model = "";
270  filename << "report-"
271  << llvm::sys::path::filename(Entry->getName()).str()
272  << "-" << declName.c_str()
273  << "-" << offsetDecl
274  << "-" << i << ".html";
275  llvm::sys::path::append(Model, Directory,
276  filename.str());
277  EC = llvm::sys::fs::openFileForReadWrite(
278  Model, FD, llvm::sys::fs::CD_CreateNew, llvm::sys::fs::OF_None);
279  if (EC && EC != llvm::errc::file_exists) {
280  llvm::errs() << "warning: could not create file '" << Model
281  << "': " << EC.message() << '\n';
282  return;
283  }
284  i++;
285  } while (EC);
286  }
287 
288  llvm::raw_fd_ostream os(FD, true);
289 
290  if (filesMade)
291  filesMade->addDiagnostic(D, getName(),
292  llvm::sys::path::filename(ResultPath));
293 
294  // Emit the HTML to disk.
295  os << report;
296 }
297 
298 std::string HTMLDiagnostics::GenerateHTML(const PathDiagnostic& D, Rewriter &R,
299  const SourceManager& SMgr, const PathPieces& path, const char *declName) {
300  // Rewrite source files as HTML for every new file the path crosses
301  std::vector<FileID> FileIDs;
302  for (auto I : path) {
303  FileID FID = I->getLocation().asLocation().getExpansionLoc().getFileID();
304  if (llvm::is_contained(FileIDs, FID))
305  continue;
306 
307  FileIDs.push_back(FID);
308  RewriteFile(R, path, FID);
309  }
310 
311  if (SupportsCrossFileDiagnostics && FileIDs.size() > 1) {
312  // Prefix file names, anchor tags, and nav cursors to every file
313  for (auto I = FileIDs.begin(), E = FileIDs.end(); I != E; I++) {
314  std::string s;
315  llvm::raw_string_ostream os(s);
316 
317  if (I != FileIDs.begin())
318  os << "<hr class=divider>\n";
319 
320  os << "<div id=File" << I->getHashValue() << ">\n";
321 
322  // Left nav arrow
323  if (I != FileIDs.begin())
324  os << "<div class=FileNav><a href=\"#File" << (I - 1)->getHashValue()
325  << "\">&#x2190;</a></div>";
326 
327  os << "<h4 class=FileName>" << SMgr.getFileEntryForID(*I)->getName()
328  << "</h4>\n";
329 
330  // Right nav arrow
331  if (I + 1 != E)
332  os << "<div class=FileNav><a href=\"#File" << (I + 1)->getHashValue()
333  << "\">&#x2192;</a></div>";
334 
335  os << "</div>\n";
336 
337  R.InsertTextBefore(SMgr.getLocForStartOfFile(*I), os.str());
338  }
339 
340  // Append files to the main report file in the order they appear in the path
341  for (auto I : llvm::make_range(FileIDs.begin() + 1, FileIDs.end())) {
342  std::string s;
343  llvm::raw_string_ostream os(s);
344 
345  const RewriteBuffer *Buf = R.getRewriteBufferFor(I);
346  for (auto BI : *Buf)
347  os << BI;
348 
349  R.InsertTextAfter(SMgr.getLocForEndOfFile(FileIDs[0]), os.str());
350  }
351  }
352 
353  const RewriteBuffer *Buf = R.getRewriteBufferFor(FileIDs[0]);
354  if (!Buf)
355  return {};
356 
357  // Add CSS, header, and footer.
358  FileID FID =
359  path.back()->getLocation().asLocation().getExpansionLoc().getFileID();
360  const FileEntry* Entry = SMgr.getFileEntryForID(FID);
361  FinalizeHTML(D, R, SMgr, path, FileIDs[0], Entry, declName);
362 
363  std::string file;
364  llvm::raw_string_ostream os(file);
365  for (auto BI : *Buf)
366  os << BI;
367 
368  return os.str();
369 }
370 
371 void HTMLDiagnostics::dumpCoverageData(
372  const PathDiagnostic &D,
373  const PathPieces &path,
374  llvm::raw_string_ostream &os) {
375 
376  const FilesToLineNumsMap &ExecutedLines = D.getExecutedLines();
377 
378  os << "var relevant_lines = {";
379  for (auto I = ExecutedLines.begin(),
380  E = ExecutedLines.end(); I != E; ++I) {
381  if (I != ExecutedLines.begin())
382  os << ", ";
383 
384  os << "\"" << I->first.getHashValue() << "\": {";
385  for (unsigned LineNo : I->second) {
386  if (LineNo != *(I->second.begin()))
387  os << ", ";
388 
389  os << "\"" << LineNo << "\": 1";
390  }
391  os << "}";
392  }
393 
394  os << "};";
395 }
396 
397 std::string HTMLDiagnostics::showRelevantLinesJavascript(
398  const PathDiagnostic &D, const PathPieces &path) {
399  std::string s;
400  llvm::raw_string_ostream os(s);
401  os << "<script type='text/javascript'>\n";
402  dumpCoverageData(D, path, os);
403  os << R"<<<(
404 
405 var filterCounterexample = function (hide) {
406  var tables = document.getElementsByClassName("code");
407  for (var t=0; t<tables.length; t++) {
408  var table = tables[t];
409  var file_id = table.getAttribute("data-fileid");
410  var lines_in_fid = relevant_lines[file_id];
411  if (!lines_in_fid) {
412  lines_in_fid = {};
413  }
414  var lines = table.getElementsByClassName("codeline");
415  for (var i=0; i<lines.length; i++) {
416  var el = lines[i];
417  var lineNo = el.getAttribute("data-linenumber");
418  if (!lines_in_fid[lineNo]) {
419  if (hide) {
420  el.setAttribute("hidden", "");
421  } else {
422  el.removeAttribute("hidden");
423  }
424  }
425  }
426  }
427 }
428 
429 window.addEventListener("keydown", function (event) {
430  if (event.defaultPrevented) {
431  return;
432  }
433  if (event.key == "S") {
434  var checked = document.getElementsByName("showCounterexample")[0].checked;
435  filterCounterexample(!checked);
436  document.getElementsByName("showCounterexample")[0].checked = !checked;
437  } else {
438  return;
439  }
440  event.preventDefault();
441 }, true);
442 
443 document.addEventListener("DOMContentLoaded", function() {
444  document.querySelector('input[name="showCounterexample"]').onchange=
445  function (event) {
446  filterCounterexample(this.checked);
447  };
448 });
449 </script>
450 
451 <form>
452  <input type="checkbox" name="showCounterexample" id="showCounterexample" />
453  <label for="showCounterexample">
454  Show only relevant lines
455  </label>
456 </form>
457 )<<<";
458 
459  return os.str();
460 }
461 
462 void HTMLDiagnostics::FinalizeHTML(const PathDiagnostic& D, Rewriter &R,
463  const SourceManager& SMgr, const PathPieces& path, FileID FID,
464  const FileEntry *Entry, const char *declName) {
465  // This is a cludge; basically we want to append either the full
466  // working directory if we have no directory information. This is
467  // a work in progress.
468 
469  llvm::SmallString<0> DirName;
470 
471  if (llvm::sys::path::is_relative(Entry->getName())) {
472  llvm::sys::fs::current_path(DirName);
473  DirName += '/';
474  }
475 
476  int LineNumber = path.back()->getLocation().asLocation().getExpansionLineNumber();
477  int ColumnNumber = path.back()->getLocation().asLocation().getExpansionColumnNumber();
478 
479  R.InsertTextBefore(SMgr.getLocForStartOfFile(FID), showHelpJavascript());
480 
482  generateKeyboardNavigationJavascript());
483 
484  // Checkbox and javascript for filtering the output to the counterexample.
486  showRelevantLinesJavascript(D, path));
487 
488  // Add the name of the file as an <h1> tag.
489  {
490  std::string s;
491  llvm::raw_string_ostream os(s);
492 
493  os << "<!-- REPORTHEADER -->\n"
494  << "<h3>Bug Summary</h3>\n<table class=\"simpletable\">\n"
495  "<tr><td class=\"rowname\">File:</td><td>"
496  << html::EscapeText(DirName)
497  << html::EscapeText(Entry->getName())
498  << "</td></tr>\n<tr><td class=\"rowname\">Warning:</td><td>"
499  "<a href=\"#EndPath\">line "
500  << LineNumber
501  << ", column "
502  << ColumnNumber
503  << "</a><br />"
504  << D.getVerboseDescription() << "</td></tr>\n";
505 
506  // The navigation across the extra notes pieces.
507  unsigned NumExtraPieces = 0;
508  for (const auto &Piece : path) {
509  if (const auto *P = dyn_cast<PathDiagnosticNotePiece>(Piece.get())) {
510  int LineNumber =
511  P->getLocation().asLocation().getExpansionLineNumber();
512  int ColumnNumber =
513  P->getLocation().asLocation().getExpansionColumnNumber();
514  os << "<tr><td class=\"rowname\">Note:</td><td>"
515  << "<a href=\"#Note" << NumExtraPieces << "\">line "
516  << LineNumber << ", column " << ColumnNumber << "</a><br />"
517  << P->getString() << "</td></tr>";
518  ++NumExtraPieces;
519  }
520  }
521 
522  // Output any other meta data.
523 
524  for (PathDiagnostic::meta_iterator I = D.meta_begin(), E = D.meta_end();
525  I != E; ++I) {
526  os << "<tr><td></td><td>" << html::EscapeText(*I) << "</td></tr>\n";
527  }
528 
529  os << R"<<<(
530 </table>
531 <!-- REPORTSUMMARYEXTRA -->
532 <h3>Annotated Source Code</h3>
533 <p>Press <a href="#" onclick="toggleHelp(); return false;">'?'</a>
534  to see keyboard shortcuts</p>
535 <input type="checkbox" class="spoilerhider" id="showinvocation" />
536 <label for="showinvocation" >Show analyzer invocation</label>
537 <div class="spoiler">clang -cc1 )<<<";
538  os << html::EscapeText(AnalyzerOpts.FullCompilerInvocation);
539  os << R"<<<(
540 </div>
541 <div id='tooltiphint' hidden="true">
542  <p>Keyboard shortcuts: </p>
543  <ul>
544  <li>Use 'j/k' keys for keyboard navigation</li>
545  <li>Use 'Shift+S' to show/hide relevant lines</li>
546  <li>Use '?' to toggle this window</li>
547  </ul>
548  <a href="#" onclick="toggleHelp(); return false;">Close</a>
549 </div>
550 )<<<";
551  R.InsertTextBefore(SMgr.getLocForStartOfFile(FID), os.str());
552  }
553 
554  // Embed meta-data tags.
555  {
556  std::string s;
557  llvm::raw_string_ostream os(s);
558 
559  StringRef BugDesc = D.getVerboseDescription();
560  if (!BugDesc.empty())
561  os << "\n<!-- BUGDESC " << BugDesc << " -->\n";
562 
563  StringRef BugType = D.getBugType();
564  if (!BugType.empty())
565  os << "\n<!-- BUGTYPE " << BugType << " -->\n";
566 
567  PathDiagnosticLocation UPDLoc = D.getUniqueingLoc();
568  FullSourceLoc L(SMgr.getExpansionLoc(UPDLoc.isValid()
569  ? UPDLoc.asLocation()
570  : D.getLocation().asLocation()),
571  SMgr);
572  const Decl *DeclWithIssue = D.getDeclWithIssue();
573 
574  StringRef BugCategory = D.getCategory();
575  if (!BugCategory.empty())
576  os << "\n<!-- BUGCATEGORY " << BugCategory << " -->\n";
577 
578  os << "\n<!-- BUGFILE " << DirName << Entry->getName() << " -->\n";
579 
580  os << "\n<!-- FILENAME " << llvm::sys::path::filename(Entry->getName()) << " -->\n";
581 
582  os << "\n<!-- FUNCTIONNAME " << declName << " -->\n";
583 
584  os << "\n<!-- ISSUEHASHCONTENTOFLINEINCONTEXT "
585  << GetIssueHash(SMgr, L, D.getCheckerName(), D.getBugType(),
586  DeclWithIssue, PP.getLangOpts())
587  << " -->\n";
588 
589  os << "\n<!-- BUGLINE "
590  << LineNumber
591  << " -->\n";
592 
593  os << "\n<!-- BUGCOLUMN "
594  << ColumnNumber
595  << " -->\n";
596 
597  os << "\n<!-- BUGPATHLENGTH " << path.size() << " -->\n";
598 
599  // Mark the end of the tags.
600  os << "\n<!-- BUGMETAEND -->\n";
601 
602  // Insert the text.
603  R.InsertTextBefore(SMgr.getLocForStartOfFile(FID), os.str());
604  }
605 
607 }
608 
609 StringRef HTMLDiagnostics::showHelpJavascript() {
610  return R"<<<(
611 <script type='text/javascript'>
612 
613 var toggleHelp = function() {
614  var hint = document.querySelector("#tooltiphint");
615  var attributeName = "hidden";
616  if (hint.hasAttribute(attributeName)) {
617  hint.removeAttribute(attributeName);
618  } else {
619  hint.setAttribute("hidden", "true");
620  }
621 };
622 window.addEventListener("keydown", function (event) {
623  if (event.defaultPrevented) {
624  return;
625  }
626  if (event.key == "?") {
627  toggleHelp();
628  } else {
629  return;
630  }
631  event.preventDefault();
632 });
633 </script>
634 )<<<";
635 }
636 
637 static bool shouldDisplayPopUpRange(const SourceRange &Range) {
638  return !(Range.getBegin().isMacroID() || Range.getEnd().isMacroID());
639 }
640 
641 static void
643  const std::vector<SourceRange> &PopUpRanges) {
644  for (const auto &Range : PopUpRanges) {
645  if (!shouldDisplayPopUpRange(Range))
646  continue;
647 
648  html::HighlightRange(R, Range.getBegin(), Range.getEnd(), "",
649  "<table class='variable_popup'><tbody>",
650  /*IsTokenRange=*/true);
651  }
652 }
653 
655  const PathDiagnosticPopUpPiece &Piece,
656  std::vector<SourceRange> &PopUpRanges,
657  unsigned int LastReportedPieceIndex,
658  unsigned int PopUpPieceIndex) {
659  SmallString<256> Buf;
660  llvm::raw_svector_ostream Out(Buf);
661 
662  SourceRange Range(Piece.getLocation().asRange());
663  if (!shouldDisplayPopUpRange(Range))
664  return;
665 
666  // Write out the path indices with a right arrow and the message as a row.
667  Out << "<tr><td valign='top'><div class='PathIndex PathIndexPopUp'>"
668  << LastReportedPieceIndex;
669 
670  // Also annotate the state transition with extra indices.
671  Out << '.' << PopUpPieceIndex;
672 
673  Out << "</div></td><td>" << Piece.getString() << "</td></tr>";
674 
675  // If no report made at this range mark the variable and add the end tags.
676  if (std::find(PopUpRanges.begin(), PopUpRanges.end(), Range) ==
677  PopUpRanges.end()) {
678  // Store that we create a report at this range.
679  PopUpRanges.push_back(Range);
680 
681  Out << "</tbody></table></span>";
682  html::HighlightRange(R, Range.getBegin(), Range.getEnd(),
683  "<span class='variable'>", Buf.c_str(),
684  /*IsTokenRange=*/true);
685  } else {
686  // Otherwise inject just the new row at the end of the range.
687  html::HighlightRange(R, Range.getBegin(), Range.getEnd(), "", Buf.c_str(),
688  /*IsTokenRange=*/true);
689  }
690 }
691 
692 void HTMLDiagnostics::RewriteFile(Rewriter &R,
693  const PathPieces& path, FileID FID) {
694  // Process the path.
695  // Maintain the counts of extra note pieces separately.
696  unsigned TotalPieces = path.size();
697  unsigned TotalNotePieces = std::count_if(
698  path.begin(), path.end(), [](const PathDiagnosticPieceRef &p) {
699  return isa<PathDiagnosticNotePiece>(*p);
700  });
701  unsigned PopUpPieceCount = std::count_if(
702  path.begin(), path.end(), [](const PathDiagnosticPieceRef &p) {
703  return isa<PathDiagnosticPopUpPiece>(*p);
704  });
705 
706  unsigned TotalRegularPieces = TotalPieces - TotalNotePieces - PopUpPieceCount;
707  unsigned NumRegularPieces = TotalRegularPieces;
708  unsigned NumNotePieces = TotalNotePieces;
709  // Stores the count of the regular piece indices.
710  std::map<int, int> IndexMap;
711 
712  // Stores the different ranges where we have reported something.
713  std::vector<SourceRange> PopUpRanges;
714  for (auto I = path.rbegin(), E = path.rend(); I != E; ++I) {
715  const auto &Piece = *I->get();
716 
717  if (isa<PathDiagnosticPopUpPiece>(Piece)) {
718  ++IndexMap[NumRegularPieces];
719  } else if (isa<PathDiagnosticNotePiece>(Piece)) {
720  // This adds diagnostic bubbles, but not navigation.
721  // Navigation through note pieces would be added later,
722  // as a separate pass through the piece list.
723  HandlePiece(R, FID, Piece, PopUpRanges, NumNotePieces, TotalNotePieces);
724  --NumNotePieces;
725  } else {
726  HandlePiece(R, FID, Piece, PopUpRanges, NumRegularPieces,
727  TotalRegularPieces);
728  --NumRegularPieces;
729  }
730  }
731 
732  // Secondary indexing if we are having multiple pop-ups between two notes.
733  // (e.g. [(13) 'a' is 'true']; [(13.1) 'b' is 'false']; [(13.2) 'c' is...)
734  NumRegularPieces = TotalRegularPieces;
735  for (auto I = path.rbegin(), E = path.rend(); I != E; ++I) {
736  const auto &Piece = *I->get();
737 
738  if (const auto *PopUpP = dyn_cast<PathDiagnosticPopUpPiece>(&Piece)) {
739  int PopUpPieceIndex = IndexMap[NumRegularPieces];
740 
741  // Pop-up pieces needs the index of the last reported piece and its count
742  // how many times we report to handle multiple reports on the same range.
743  // This marks the variable, adds the </table> end tag and the message
744  // (list element) as a row. The <table> start tag will be added after the
745  // rows has been written out. Note: It stores every different range.
746  HandlePopUpPieceEndTag(R, *PopUpP, PopUpRanges, NumRegularPieces,
747  PopUpPieceIndex);
748 
749  if (PopUpPieceIndex > 0)
750  --IndexMap[NumRegularPieces];
751 
752  } else if (!isa<PathDiagnosticNotePiece>(Piece)) {
753  --NumRegularPieces;
754  }
755  }
756 
757  // Add the <table> start tag of pop-up pieces based on the stored ranges.
758  HandlePopUpPieceStartTag(R, PopUpRanges);
759 
760  // Add line numbers, header, footer, etc.
761  html::EscapeText(R, FID);
762  html::AddLineNumbers(R, FID);
763 
764  // If we have a preprocessor, relex the file and syntax highlight.
765  // We might not have a preprocessor if we come from a deserialized AST file,
766  // for example.
767  html::SyntaxHighlight(R, FID, PP);
768  html::HighlightMacros(R, FID, PP);
769 }
770 
771 void HTMLDiagnostics::HandlePiece(Rewriter &R, FileID BugFileID,
772  const PathDiagnosticPiece &P,
773  const std::vector<SourceRange> &PopUpRanges,
774  unsigned num, unsigned max) {
775  // For now, just draw a box above the line in question, and emit the
776  // warning.
777  FullSourceLoc Pos = P.getLocation().asLocation();
778 
779  if (!Pos.isValid())
780  return;
781 
783  assert(&Pos.getManager() == &SM && "SourceManagers are different!");
784  std::pair<FileID, unsigned> LPosInfo = SM.getDecomposedExpansionLoc(Pos);
785 
786  if (LPosInfo.first != BugFileID)
787  return;
788 
789  const llvm::MemoryBuffer *Buf = SM.getBuffer(LPosInfo.first);
790  const char* FileStart = Buf->getBufferStart();
791 
792  // Compute the column number. Rewind from the current position to the start
793  // of the line.
794  unsigned ColNo = SM.getColumnNumber(LPosInfo.first, LPosInfo.second);
795  const char *TokInstantiationPtr =Pos.getExpansionLoc().getCharacterData();
796  const char *LineStart = TokInstantiationPtr-ColNo;
797 
798  // Compute LineEnd.
799  const char *LineEnd = TokInstantiationPtr;
800  const char* FileEnd = Buf->getBufferEnd();
801  while (*LineEnd != '\n' && LineEnd != FileEnd)
802  ++LineEnd;
803 
804  // Compute the margin offset by counting tabs and non-tabs.
805  unsigned PosNo = 0;
806  for (const char* c = LineStart; c != TokInstantiationPtr; ++c)
807  PosNo += *c == '\t' ? 8 : 1;
808 
809  // Create the html for the message.
810 
811  const char *Kind = nullptr;
812  bool IsNote = false;
813  bool SuppressIndex = (max == 1);
814  switch (P.getKind()) {
815  case PathDiagnosticPiece::Event: Kind = "Event"; break;
816  case PathDiagnosticPiece::ControlFlow: Kind = "Control"; break;
817  // Setting Kind to "Control" is intentional.
818  case PathDiagnosticPiece::Macro: Kind = "Control"; break;
820  Kind = "Note";
821  IsNote = true;
822  SuppressIndex = true;
823  break;
826  llvm_unreachable("Calls and extra notes should already be handled");
827  }
828 
829  std::string sbuf;
830  llvm::raw_string_ostream os(sbuf);
831 
832  os << "\n<tr><td class=\"num\"></td><td class=\"line\"><div id=\"";
833 
834  if (IsNote)
835  os << "Note" << num;
836  else if (num == max)
837  os << "EndPath";
838  else
839  os << "Path" << num;
840 
841  os << "\" class=\"msg";
842  if (Kind)
843  os << " msg" << Kind;
844  os << "\" style=\"margin-left:" << PosNo << "ex";
845 
846  // Output a maximum size.
847  if (!isa<PathDiagnosticMacroPiece>(P)) {
848  // Get the string and determining its maximum substring.
849  const auto &Msg = P.getString();
850  unsigned max_token = 0;
851  unsigned cnt = 0;
852  unsigned len = Msg.size();
853 
854  for (char C : Msg)
855  switch (C) {
856  default:
857  ++cnt;
858  continue;
859  case ' ':
860  case '\t':
861  case '\n':
862  if (cnt > max_token) max_token = cnt;
863  cnt = 0;
864  }
865 
866  if (cnt > max_token)
867  max_token = cnt;
868 
869  // Determine the approximate size of the message bubble in em.
870  unsigned em;
871  const unsigned max_line = 120;
872 
873  if (max_token >= max_line)
874  em = max_token / 2;
875  else {
876  unsigned characters = max_line;
877  unsigned lines = len / max_line;
878 
879  if (lines > 0) {
880  for (; characters > max_token; --characters)
881  if (len / characters > lines) {
882  ++characters;
883  break;
884  }
885  }
886 
887  em = characters / 2;
888  }
889 
890  if (em < max_line/2)
891  os << "; max-width:" << em << "em";
892  }
893  else
894  os << "; max-width:100em";
895 
896  os << "\">";
897 
898  if (!SuppressIndex) {
899  os << "<table class=\"msgT\"><tr><td valign=\"top\">";
900  os << "<div class=\"PathIndex";
901  if (Kind) os << " PathIndex" << Kind;
902  os << "\">" << num << "</div>";
903 
904  if (num > 1) {
905  os << "</td><td><div class=\"PathNav\"><a href=\"#Path"
906  << (num - 1)
907  << "\" title=\"Previous event ("
908  << (num - 1)
909  << ")\">&#x2190;</a></div>";
910  }
911 
912  os << "</td><td>";
913  }
914 
915  if (const auto *MP = dyn_cast<PathDiagnosticMacroPiece>(&P)) {
916  os << "Within the expansion of the macro '";
917 
918  // Get the name of the macro by relexing it.
919  {
920  FullSourceLoc L = MP->getLocation().asLocation().getExpansionLoc();
921  assert(L.isFileID());
922  StringRef BufferInfo = L.getBufferData();
923  std::pair<FileID, unsigned> LocInfo = L.getDecomposedLoc();
924  const char* MacroName = LocInfo.second + BufferInfo.data();
925  Lexer rawLexer(SM.getLocForStartOfFile(LocInfo.first), PP.getLangOpts(),
926  BufferInfo.begin(), MacroName, BufferInfo.end());
927 
928  Token TheTok;
929  rawLexer.LexFromRawLexer(TheTok);
930  for (unsigned i = 0, n = TheTok.getLength(); i < n; ++i)
931  os << MacroName[i];
932  }
933 
934  os << "':\n";
935 
936  if (!SuppressIndex) {
937  os << "</td>";
938  if (num < max) {
939  os << "<td><div class=\"PathNav\"><a href=\"#";
940  if (num == max - 1)
941  os << "EndPath";
942  else
943  os << "Path" << (num + 1);
944  os << "\" title=\"Next event ("
945  << (num + 1)
946  << ")\">&#x2192;</a></div></td>";
947  }
948 
949  os << "</tr></table>";
950  }
951 
952  // Within a macro piece. Write out each event.
953  ProcessMacroPiece(os, *MP, 0);
954  }
955  else {
956  os << html::EscapeText(P.getString());
957 
958  if (!SuppressIndex) {
959  os << "</td>";
960  if (num < max) {
961  os << "<td><div class=\"PathNav\"><a href=\"#";
962  if (num == max - 1)
963  os << "EndPath";
964  else
965  os << "Path" << (num + 1);
966  os << "\" title=\"Next event ("
967  << (num + 1)
968  << ")\">&#x2192;</a></div></td>";
969  }
970 
971  os << "</tr></table>";
972  }
973  }
974 
975  os << "</div></td></tr>";
976 
977  // Insert the new html.
978  unsigned DisplayPos = LineEnd - FileStart;
979  SourceLocation Loc =
980  SM.getLocForStartOfFile(LPosInfo.first).getLocWithOffset(DisplayPos);
981 
982  R.InsertTextBefore(Loc, os.str());
983 
984  // Now highlight the ranges.
985  ArrayRef<SourceRange> Ranges = P.getRanges();
986  for (const auto &Range : Ranges) {
987  // If we have already highlighted the range as a pop-up there is no work.
988  if (std::find(PopUpRanges.begin(), PopUpRanges.end(), Range) !=
989  PopUpRanges.end())
990  continue;
991 
992  HighlightRange(R, LPosInfo.first, Range);
993  }
994 }
995 
996 static void EmitAlphaCounter(raw_ostream &os, unsigned n) {
997  unsigned x = n % ('z' - 'a');
998  n /= 'z' - 'a';
999 
1000  if (n > 0)
1001  EmitAlphaCounter(os, n);
1002 
1003  os << char('a' + x);
1004 }
1005 
1006 unsigned HTMLDiagnostics::ProcessMacroPiece(raw_ostream &os,
1007  const PathDiagnosticMacroPiece& P,
1008  unsigned num) {
1009  for (const auto &subPiece : P.subPieces) {
1010  if (const auto *MP = dyn_cast<PathDiagnosticMacroPiece>(subPiece.get())) {
1011  num = ProcessMacroPiece(os, *MP, num);
1012  continue;
1013  }
1014 
1015  if (const auto *EP = dyn_cast<PathDiagnosticEventPiece>(subPiece.get())) {
1016  os << "<div class=\"msg msgEvent\" style=\"width:94%; "
1017  "margin-left:5px\">"
1018  "<table class=\"msgT\"><tr>"
1019  "<td valign=\"top\"><div class=\"PathIndex PathIndexEvent\">";
1020  EmitAlphaCounter(os, num++);
1021  os << "</div></td><td valign=\"top\">"
1022  << html::EscapeText(EP->getString())
1023  << "</td></tr></table></div>\n";
1024  }
1025  }
1026 
1027  return num;
1028 }
1029 
1031  SourceRange Range,
1032  const char *HighlightStart,
1033  const char *HighlightEnd) {
1034  SourceManager &SM = R.getSourceMgr();
1035  const LangOptions &LangOpts = R.getLangOpts();
1036 
1037  SourceLocation InstantiationStart = SM.getExpansionLoc(Range.getBegin());
1038  unsigned StartLineNo = SM.getExpansionLineNumber(InstantiationStart);
1039 
1040  SourceLocation InstantiationEnd = SM.getExpansionLoc(Range.getEnd());
1041  unsigned EndLineNo = SM.getExpansionLineNumber(InstantiationEnd);
1042 
1043  if (EndLineNo < StartLineNo)
1044  return;
1045 
1046  if (SM.getFileID(InstantiationStart) != BugFileID ||
1047  SM.getFileID(InstantiationEnd) != BugFileID)
1048  return;
1049 
1050  // Compute the column number of the end.
1051  unsigned EndColNo = SM.getExpansionColumnNumber(InstantiationEnd);
1052  unsigned OldEndColNo = EndColNo;
1053 
1054  if (EndColNo) {
1055  // Add in the length of the token, so that we cover multi-char tokens.
1056  EndColNo += Lexer::MeasureTokenLength(Range.getEnd(), SM, LangOpts)-1;
1057  }
1058 
1059  // Highlight the range. Make the span tag the outermost tag for the
1060  // selected range.
1061 
1062  SourceLocation E =
1063  InstantiationEnd.getLocWithOffset(EndColNo - OldEndColNo);
1064 
1065  html::HighlightRange(R, InstantiationStart, E, HighlightStart, HighlightEnd);
1066 }
1067 
1068 StringRef HTMLDiagnostics::generateKeyboardNavigationJavascript() {
1069  return R"<<<(
1070 <script type='text/javascript'>
1071 var digitMatcher = new RegExp("[0-9]+");
1072 
1073 var querySelectorAllArray = function(selector) {
1074  return Array.prototype.slice.call(
1075  document.querySelectorAll(selector));
1076 }
1077 
1078 document.addEventListener("DOMContentLoaded", function() {
1079  querySelectorAllArray(".PathNav > a").forEach(
1080  function(currentValue, currentIndex) {
1081  var hrefValue = currentValue.getAttribute("href");
1082  currentValue.onclick = function() {
1083  scrollTo(document.querySelector(hrefValue));
1084  return false;
1085  };
1086  });
1087 });
1088 
1089 var findNum = function() {
1090  var s = document.querySelector(".selected");
1091  if (!s || s.id == "EndPath") {
1092  return 0;
1093  }
1094  var out = parseInt(digitMatcher.exec(s.id)[0]);
1095  return out;
1096 };
1097 
1098 var scrollTo = function(el) {
1099  querySelectorAllArray(".selected").forEach(function(s) {
1100  s.classList.remove("selected");
1101  });
1102  el.classList.add("selected");
1103  window.scrollBy(0, el.getBoundingClientRect().top -
1104  (window.innerHeight / 2));
1105 }
1106 
1107 var move = function(num, up, numItems) {
1108  if (num == 1 && up || num == numItems - 1 && !up) {
1109  return 0;
1110  } else if (num == 0 && up) {
1111  return numItems - 1;
1112  } else if (num == 0 && !up) {
1113  return 1 % numItems;
1114  }
1115  return up ? num - 1 : num + 1;
1116 }
1117 
1118 var numToId = function(num) {
1119  if (num == 0) {
1120  return document.getElementById("EndPath")
1121  }
1122  return document.getElementById("Path" + num);
1123 };
1124 
1125 var navigateTo = function(up) {
1126  var numItems = document.querySelectorAll(
1127  ".line > .msgEvent, .line > .msgControl").length;
1128  var currentSelected = findNum();
1129  var newSelected = move(currentSelected, up, numItems);
1130  var newEl = numToId(newSelected, numItems);
1131 
1132  // Scroll element into center.
1133  scrollTo(newEl);
1134 };
1135 
1136 window.addEventListener("keydown", function (event) {
1137  if (event.defaultPrevented) {
1138  return;
1139  }
1140  if (event.key == "j") {
1141  navigateTo(/*up=*/false);
1142  } else if (event.key == "k") {
1143  navigateTo(/*up=*/true);
1144  } else {
1145  return;
1146  }
1147  event.preventDefault();
1148 }, true);
1149 </script>
1150  )<<<";
1151 }
SourceLocation getLocForStartOfFile(FileID FID) const
Return the source location corresponding to the first byte of the specified file. ...
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
Lexer - This provides a simple interface that turns a text buffer into a stream of tokens...
Definition: Lexer.h:76
SourceLocation getLocWithOffset(int Offset) const
Return a source location with the specified offset from this SourceLocation.
SourceLocation getLocForEndOfFile(FileID FID) const
Return the source location corresponding to the last byte of the specified file.
Defines the clang::FileManager interface and associated types.
FullSourceLoc getExpansionLoc() const
Stmt - This represents one statement.
Definition: Stmt.h:68
static bool shouldDisplayPopUpRange(const SourceRange &Range)
Defines the SourceManager interface.
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:89
StringRef P
unsigned getColumnNumber(FileID FID, unsigned FilePos, bool *Invalid=nullptr) const
Return the column # for the specified file position.
llvm::SmallString< 32 > GetIssueHash(const SourceManager &SM, FullSourceLoc &IssueLoc, llvm::StringRef CheckerName, llvm::StringRef BugType, const Decl *D, const LangOptions &LangOpts)
Get an MD5 hash to help identify bugs.
RewriteBuffer - As code is rewritten, SourceBuffer&#39;s from the original input with modifications get a...
Definition: RewriteBuffer.h:25
void HighlightMacros(Rewriter &R, FileID FID, const Preprocessor &PP)
HighlightMacros - This uses the macro table state from the end of the file, to reexpand macros and in...
void AddLineNumbers(Rewriter &R, FileID FID)
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:54
const LangOptions & getLangOpts() const
Definition: Preprocessor.h:915
std::shared_ptr< PathDiagnosticPiece > PathDiagnosticPieceRef
std::pair< FileID, unsigned > getDecomposedExpansionLoc(SourceLocation Loc) const
Decompose the specified location into a raw FileID + Offset pair.
static void HandlePopUpPieceStartTag(Rewriter &R, const std::vector< SourceRange > &PopUpRanges)
SourceManager & getSourceMgr() const
Definition: Rewriter.h:77
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
SourceLocation getExpansionLoc(SourceLocation Loc) const
Given a SourceLocation object Loc, return the expansion location referenced by the ID...
std::string FullCompilerInvocation
Store full compiler invocation for reproducible instructions in the generated report.
void SyntaxHighlight(Rewriter &R, FileID FID, const Preprocessor &PP)
SyntaxHighlight - Relex the specified FileID and annotate the HTML with information about keywords...
__device__ __2f16 float bool s
static void HandlePopUpPieceEndTag(Rewriter &R, const PathDiagnosticPopUpPiece &Piece, std::vector< SourceRange > &PopUpRanges, unsigned int LastReportedPieceIndex, unsigned int PopUpPieceIndex)
std::pair< FileID, unsigned > getDecomposedLoc() const
Decompose the specified location into a raw FileID + Offset pair.
static unsigned MeasureTokenLength(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
MeasureTokenLength - Relex the token at the specified location and return its length in bytes in the ...
Definition: Lexer.cpp:445
const FileEntry * getFileEntryForID(FileID FID) const
Returns the FileEntry record for the provided FileID.
static void EmitAlphaCounter(raw_ostream &os, unsigned n)
const char * getCharacterData(bool *Invalid=nullptr) const
Defines the clang::Preprocessor interface.
const SourceManager & getManager() const
SourceLocation getEnd() const
#define SM(sm)
Definition: Cuda.cpp:62
std::map< FileID, std::set< unsigned > > FilesToLineNumsMap
File IDs mapped to sets of line numbers.
unsigned getExpansionLineNumber(SourceLocation Loc, bool *Invalid=nullptr) const
Kind
Encodes a location in the source.
StringRef getName() const
Definition: FileManager.h:103
std::vector< PathDiagnosticConsumer * > PathDiagnosticConsumers
void EscapeText(Rewriter &R, FileID FID, bool EscapeSpaces=false, bool ReplaceTabs=false)
EscapeText - HTMLize a specified file so that special characters are are translated so that they are ...
bool InsertTextAfter(SourceLocation Loc, StringRef Str)
InsertTextAfter - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.h:123
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:79
std::deque< std::string >::const_iterator meta_iterator
const RewriteBuffer * getRewriteBufferFor(FileID FID) const
getRewriteBufferFor - Return the rewrite buffer for the specified FileID.
Definition: Rewriter.h:198
StringRef getBufferData(bool *Invalid=nullptr) const
Return a StringRef to the source buffer data for the specified FileID.
bool InsertTextBefore(SourceLocation Loc, StringRef Str)
InsertText - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.h:136
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
unsigned getExpansionColumnNumber(SourceLocation Loc, bool *Invalid=nullptr) const
const llvm::MemoryBuffer * getBuffer(FileID FID, SourceLocation Loc, bool *Invalid=nullptr) const
Return the buffer for the specified FileID.
Dataflow Directional Tag Classes.
bool isValid() const
Return true if this is a valid SourceLocation object.
static std::string getName(const CallEvent &Call)
void AddHeaderFooterInternalBuiltinCSS(Rewriter &R, FileID FID, StringRef title)
This class is used for tools that requires cross translation unit capability.
bool isMacroID() const
FileID getFileID(SourceLocation SpellingLoc) const
Return the FileID for a SourceLocation.
const LangOptions & getLangOpts() const
Definition: Rewriter.h:78
Stores options for the analyzer from the command line.
__DEVICE__ int max(int __a, int __b)
Rewriter - This is the main interface to the rewrite buffers.
Definition: Rewriter.h:32
Defines the clang::SourceLocation class and associated facilities.
void HighlightRange(Rewriter &R, SourceLocation B, SourceLocation E, const char *StartTag, const char *EndTag, bool IsTokenRange=true)
HighlightRange - Highlight a range in the source code with the specified start/end tags...
Definition: HTMLRewrite.cpp:31
A SourceLocation and its associated SourceManager.
A trivial tuple used to represent a source range.
SourceLocation getBegin() const
This class handles loading and caching of source files into memory.
__device__ __2f16 float c
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:128