1//===--- SarifDiagnostics.cpp - Sarif Diagnostics for Paths -----*- C++ -*-===//
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 SarifDiagnostics object.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Analysis/PathDiagnostic.h"
14#include "clang/Basic/FileManager.h"
15#include "clang/Basic/Version.h"
16#include "clang/Lex/Preprocessor.h"
17#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
18#include "clang/StaticAnalyzer/Core/PathDiagnosticConsumers.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/ADT/StringMap.h"
21#include "llvm/Support/ConvertUTF.h"
22#include "llvm/Support/JSON.h"
23#include "llvm/Support/Path.h"
24
25using namespace llvm;
26using namespace clang;
27using namespace ento;
28
29namespace {
30class SarifDiagnostics : public PathDiagnosticConsumer {
31  std::string OutputFile;
32  const LangOptions &LO;
33
34public:
35  SarifDiagnostics(AnalyzerOptions &, const std::string &Output,
36                   const LangOptions &LO)
37      : OutputFile(Output), LO(LO) {}
38  ~SarifDiagnostics() override = default;
39
40  void FlushDiagnosticsImpl(std::vector<const PathDiagnostic *> &Diags,
41                            FilesMade *FM) override;
42
43  StringRef getName() const override { return "SarifDiagnostics"; }
44  PathGenerationScheme getGenerationScheme() const override { return Minimal; }
45  bool supportsLogicalOpControlFlow() const override { return true; }
46  bool supportsCrossFileDiagnostics() const override { return true; }
47};
48} // end anonymous namespace
49
50void ento::createSarifDiagnosticConsumer(
51    AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
52    const std::string &Output, const Preprocessor &PP,
53    const cross_tu::CrossTranslationUnitContext &CTU) {
54
55  // TODO: Emit an error here.
56  if (Output.empty())
57    return;
58
59  C.push_back(new SarifDiagnostics(AnalyzerOpts, Output, PP.getLangOpts()));
60  createTextMinimalPathDiagnosticConsumer(AnalyzerOpts, C, Output, PP, CTU);
61}
62
63static StringRef getFileName(const FileEntry &FE) {
64  StringRef Filename = FE.tryGetRealPathName();
65  if (Filename.empty())
66    Filename = FE.getName();
67  return Filename;
68}
69
70static std::string percentEncodeURICharacter(char C) {
71  // RFC 3986 claims alpha, numeric, and this handful of
72  // characters are not reserved for the path component and
73  // should be written out directly. Otherwise, percent
74  // encode the character and write that out instead of the
75  // reserved character.
76  if (llvm::isAlnum(C) ||
77      StringRef::npos != StringRef("-._~:@!$&'()*+,;=").find(C))
78    return std::string(&C, 1);
79  return "%" + llvm::toHex(StringRef(&C, 1));
80}
81
82static std::string fileNameToURI(StringRef Filename) {
83  llvm::SmallString<32> Ret = StringRef("file://");
84
85  // Get the root name to see if it has a URI authority.
86  StringRef Root = sys::path::root_name(Filename);
87  if (Root.startswith("//")) {
88    // There is an authority, so add it to the URI.
89    Ret += Root.drop_front(2).str();
90  } else if (!Root.empty()) {
91    // There is no authority, so end the component and add the root to the URI.
92    Ret += Twine("/" + Root).str();
93  }
94
95  auto Iter = sys::path::begin(Filename), End = sys::path::end(Filename);
96  assert(Iter != End && "Expected there to be a non-root path component.");
97  // Add the rest of the path components, encoding any reserved characters;
98  // we skip past the first path component, as it was handled it above.
99  std::for_each(++Iter, End, [&Ret](StringRef Component) {
100    // For reasons unknown to me, we may get a backslash with Windows native
101    // paths for the initial backslash following the drive component, which
102    // we need to ignore as a URI path part.
103    if (Component == "\\")
104      return;
105
106    // Add the separator between the previous path part and the one being
107    // currently processed.
108    Ret += "/";
109
110    // URI encode the part.
111    for (char C : Component) {
112      Ret += percentEncodeURICharacter(C);
113    }
114  });
115
116  return std::string(Ret);
117}
118
119static json::Object createArtifactLocation(const FileEntry &FE) {
120  return json::Object{{"uri", fileNameToURI(getFileName(FE))}};
121}
122
123static json::Object createArtifact(const FileEntry &FE) {
124  return json::Object{{"location", createArtifactLocation(FE)},
125                      {"roles", json::Array{"resultFile"}},
126                      {"length", FE.getSize()},
127                      {"mimeType", "text/plain"}};
128}
129
130static json::Object createArtifactLocation(const FileEntry &FE,
131                                           json::Array &Artifacts) {
132  std::string FileURI = fileNameToURI(getFileName(FE));
133
134  // See if the Artifacts array contains this URI already. If it does not,
135  // create a new artifact object to add to the array.
136  auto I = llvm::find_if(Artifacts, [&](const json::Value &File) {
137    if (const json::Object *Obj = File.getAsObject()) {
138      if (const json::Object *FileLoc = Obj->getObject("location")) {
139        Optional<StringRef> URI = FileLoc->getString("uri");
140        return URI && URI->equals(FileURI);
141      }
142    }
143    return false;
144  });
145
146  // Calculate the index within the artifact array so it can be stored in
147  // the JSON object.
148  auto Index = static_cast<unsigned>(std::distance(Artifacts.begin(), I));
149  if (I == Artifacts.end())
150    Artifacts.push_back(createArtifact(FE));
151
152  return json::Object{{"uri", FileURI}, {"index", Index}};
153}
154
155static unsigned int adjustColumnPos(const SourceManager &SM, SourceLocation Loc,
156                                    unsigned int TokenLen = 0) {
157  assert(!Loc.isInvalid() && "invalid Loc when adjusting column position");
158
159  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedExpansionLoc(Loc);
160  assert(LocInfo.second > SM.getExpansionColumnNumber(Loc) &&
161         "position in file is before column number?");
162
163  bool InvalidBuffer = false;
164  const MemoryBuffer *Buf = SM.getBuffer(LocInfo.first, &InvalidBuffer);
165  assert(!InvalidBuffer && "got an invalid buffer for the location's file");
166  assert(Buf->getBufferSize() >= (LocInfo.second + TokenLen) &&
167         "token extends past end of buffer?");
168
169  // Adjust the offset to be the start of the line, since we'll be counting
170  // Unicode characters from there until our column offset.
171  unsigned int Off = LocInfo.second - (SM.getExpansionColumnNumber(Loc) - 1);
172  unsigned int Ret = 1;
173  while (Off < (LocInfo.second + TokenLen)) {
174    Off += getNumBytesForUTF8(Buf->getBuffer()[Off]);
175    Ret++;
176  }
177
178  return Ret;
179}
180
181static json::Object createTextRegion(const LangOptions &LO, SourceRange R,
182                                     const SourceManager &SM) {
183  json::Object Region{
184      {"startLine", SM.getExpansionLineNumber(R.getBegin())},
185      {"startColumn", adjustColumnPos(SM, R.getBegin())},
186  };
187  if (R.getBegin() == R.getEnd()) {
188    Region["endColumn"] = adjustColumnPos(SM, R.getBegin());
189  } else {
190    Region["endLine"] = SM.getExpansionLineNumber(R.getEnd());
191    Region["endColumn"] = adjustColumnPos(
192        SM, R.getEnd(),
193        Lexer::MeasureTokenLength(R.getEnd(), SM, LO));
194  }
195  return Region;
196}
197
198static json::Object createPhysicalLocation(const LangOptions &LO,
199                                           SourceRange R, const FileEntry &FE,
200                                           const SourceManager &SMgr,
201                                           json::Array &Artifacts) {
202  return json::Object{
203      {{"artifactLocation", createArtifactLocation(FE, Artifacts)},
204       {"region", createTextRegion(LO, R, SMgr)}}};
205}
206
207enum class Importance { Important, Essential, Unimportant };
208
209static StringRef importanceToStr(Importance I) {
210  switch (I) {
211  case Importance::Important:
212    return "important";
213  case Importance::Essential:
214    return "essential";
215  case Importance::Unimportant:
216    return "unimportant";
217  }
218  llvm_unreachable("Fully covered switch is not so fully covered");
219}
220
221static json::Object createThreadFlowLocation(json::Object &&Location,
222                                             Importance I) {
223  return json::Object{{"location", std::move(Location)},
224                      {"importance", importanceToStr(I)}};
225}
226
227static json::Object createMessage(StringRef Text) {
228  return json::Object{{"text", Text.str()}};
229}
230
231static json::Object createLocation(json::Object &&PhysicalLocation,
232                                   StringRef Message = "") {
233  json::Object Ret{{"physicalLocation", std::move(PhysicalLocation)}};
234  if (!Message.empty())
235    Ret.insert({"message", createMessage(Message)});
236  return Ret;
237}
238
239static Importance calculateImportance(const PathDiagnosticPiece &Piece) {
240  switch (Piece.getKind()) {
241  case PathDiagnosticPiece::Call:
242  case PathDiagnosticPiece::Macro:
243  case PathDiagnosticPiece::Note:
244  case PathDiagnosticPiece::PopUp:
245    // FIXME: What should be reported here?
246    break;
247  case PathDiagnosticPiece::Event:
248    return Piece.getTagStr() == "ConditionBRVisitor" ? Importance::Important
249                                                     : Importance::Essential;
250  case PathDiagnosticPiece::ControlFlow:
251    return Importance::Unimportant;
252  }
253  return Importance::Unimportant;
254}
255
256static json::Object createThreadFlow(const LangOptions &LO,
257                                     const PathPieces &Pieces,
258                                     json::Array &Artifacts) {
259  const SourceManager &SMgr = Pieces.front()->getLocation().getManager();
260  json::Array Locations;
261  for (const auto &Piece : Pieces) {
262    const PathDiagnosticLocation &P = Piece->getLocation();
263    Locations.push_back(createThreadFlowLocation(
264        createLocation(createPhysicalLocation(
265                           LO, P.asRange(),
266                           *P.asLocation().getExpansionLoc().getFileEntry(),
267                           SMgr, Artifacts),
268                       Piece->getString()),
269        calculateImportance(*Piece)));
270  }
271  return json::Object{{"locations", std::move(Locations)}};
272}
273
274static json::Object createCodeFlow(const LangOptions &LO,
275                                   const PathPieces &Pieces,
276                                   json::Array &Artifacts) {
277  return json::Object{
278      {"threadFlows", json::Array{createThreadFlow(LO, Pieces, Artifacts)}}};
279}
280
281static json::Object createResult(const LangOptions &LO,
282                                 const PathDiagnostic &Diag,
283                                 json::Array &Artifacts,
284                                 const StringMap<unsigned> &RuleMapping) {
285  const PathPieces &Path = Diag.path.flatten(false);
286  const SourceManager &SMgr = Path.front()->getLocation().getManager();
287
288  auto Iter = RuleMapping.find(Diag.getCheckerName());
289  assert(Iter != RuleMapping.end() && "Rule ID is not in the array index map?");
290
291  return json::Object{
292      {"message", createMessage(Diag.getVerboseDescription())},
293      {"codeFlows", json::Array{createCodeFlow(LO, Path, Artifacts)}},
294      {"locations",
295       json::Array{createLocation(createPhysicalLocation(
296           LO, Diag.getLocation().asRange(),
297           *Diag.getLocation().asLocation().getExpansionLoc().getFileEntry(),
298           SMgr, Artifacts))}},
299      {"ruleIndex", Iter->getValue()},
300      {"ruleId", Diag.getCheckerName()}};
301}
302
303static StringRef getRuleDescription(StringRef CheckName) {
304  return llvm::StringSwitch<StringRef>(CheckName)
305#define GET_CHECKERS
306#define CHECKER(FULLNAME, CLASS, HELPTEXT, DOC_URI, IS_HIDDEN)                 \
307  .Case(FULLNAME, HELPTEXT)
308#include "clang/StaticAnalyzer/Checkers/Checkers.inc"
309#undef CHECKER
310#undef GET_CHECKERS
311      ;
312}
313
314static StringRef getRuleHelpURIStr(StringRef CheckName) {
315  return llvm::StringSwitch<StringRef>(CheckName)
316#define GET_CHECKERS
317#define CHECKER(FULLNAME, CLASS, HELPTEXT, DOC_URI, IS_HIDDEN)                 \
318  .Case(FULLNAME, DOC_URI)
319#include "clang/StaticAnalyzer/Checkers/Checkers.inc"
320#undef CHECKER
321#undef GET_CHECKERS
322      ;
323}
324
325static json::Object createRule(const PathDiagnostic &Diag) {
326  StringRef CheckName = Diag.getCheckerName();
327  json::Object Ret{
328      {"fullDescription", createMessage(getRuleDescription(CheckName))},
329      {"name", CheckName},
330      {"id", CheckName}};
331
332  std::string RuleURI = std::string(getRuleHelpURIStr(CheckName));
333  if (!RuleURI.empty())
334    Ret["helpUri"] = RuleURI;
335
336  return Ret;
337}
338
339static json::Array createRules(std::vector<const PathDiagnostic *> &Diags,
340                               StringMap<unsigned> &RuleMapping) {
341  json::Array Rules;
342  llvm::StringSet<> Seen;
343
344  llvm::for_each(Diags, [&](const PathDiagnostic *D) {
345    StringRef RuleID = D->getCheckerName();
346    std::pair<llvm::StringSet<>::iterator, bool> P = Seen.insert(RuleID);
347    if (P.second) {
348      RuleMapping[RuleID] = Rules.size(); // Maps RuleID to an Array Index.
349      Rules.push_back(createRule(*D));
350    }
351  });
352
353  return Rules;
354}
355
356static json::Object createTool(std::vector<const PathDiagnostic *> &Diags,
357                               StringMap<unsigned> &RuleMapping) {
358  return json::Object{
359      {"driver", json::Object{{"name", "clang"},
360                              {"fullName", "clang static analyzer"},
361                              {"language", "en-US"},
362                              {"version", getClangFullVersion()},
363                              {"rules", createRules(Diags, RuleMapping)}}}};
364}
365
366static json::Object createRun(const LangOptions &LO,
367                              std::vector<const PathDiagnostic *> &Diags) {
368  json::Array Results, Artifacts;
369  StringMap<unsigned> RuleMapping;
370  json::Object Tool = createTool(Diags, RuleMapping);
371
372  llvm::for_each(Diags, [&](const PathDiagnostic *D) {
373    Results.push_back(createResult(LO, *D, Artifacts, RuleMapping));
374  });
375
376  return json::Object{{"tool", std::move(Tool)},
377                      {"results", std::move(Results)},
378                      {"artifacts", std::move(Artifacts)},
379                      {"columnKind", "unicodeCodePoints"}};
380}
381
382void SarifDiagnostics::FlushDiagnosticsImpl(
383    std::vector<const PathDiagnostic *> &Diags, FilesMade *) {
384  // We currently overwrite the file if it already exists. However, it may be
385  // useful to add a feature someday that allows the user to append a run to an
386  // existing SARIF file. One danger from that approach is that the size of the
387  // file can become large very quickly, so decoding into JSON to append a run
388  // may be an expensive operation.
389  std::error_code EC;
390  llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::OF_Text);
391  if (EC) {
392    llvm::errs() << "warning: could not create file: " << EC.message() << '\n';
393    return;
394  }
395  json::Object Sarif{
396      {"$schema",
397       "https://raw.githubusercontent.com/oasis-tcs/sarif-spec/master/Schemata/sarif-schema-2.1.0.json"},
398      {"version", "2.1.0"},
399      {"runs", json::Array{createRun(LO, Diags)}}};
400  OS << llvm::formatv("{0:2}\n", json::Value(std::move(Sarif)));
401}
402