1//===--- SanitizerArgs.cpp - Arguments for sanitizer tools  ---------------===//
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#include "clang/Driver/SanitizerArgs.h"
10#include "clang/Driver/Driver.h"
11#include "clang/Driver/DriverDiagnostic.h"
12#include "clang/Driver/Options.h"
13#include "clang/Driver/ToolChain.h"
14#include "llvm/ADT/StringExtras.h"
15#include "llvm/ADT/StringSwitch.h"
16#include "llvm/Support/FileSystem.h"
17#include "llvm/Support/Path.h"
18#include "llvm/Support/SpecialCaseList.h"
19#include <memory>
20
21using namespace clang::driver;
22using namespace llvm::opt;
23
24void SanitizerArgs::clear() {
25  Kind = 0;
26  BlacklistFile = "";
27  MsanTrackOrigins = 0;
28  AsanZeroBaseShadow = false;
29  UbsanTrapOnError = false;
30  AsanSharedRuntime = false;
31}
32
33SanitizerArgs::SanitizerArgs() {
34  clear();
35}
36
37SanitizerArgs::SanitizerArgs(const ToolChain &TC,
38                             const llvm::opt::ArgList &Args) {
39  clear();
40  unsigned AllAdd = 0;  // All kinds of sanitizers that were turned on
41                        // at least once (possibly, disabled further).
42  unsigned AllRemove = 0;  // During the loop below, the accumulated set of
43                           // sanitizers disabled by the current sanitizer
44                           // argument or any argument after it.
45  unsigned DiagnosedKinds = 0;  // All Kinds we have diagnosed up to now.
46                                // Used to deduplicate diagnostics.
47  const Driver &D = TC.getDriver();
48  for (ArgList::const_reverse_iterator I = Args.rbegin(), E = Args.rend();
49       I != E; ++I) {
50    unsigned Add, Remove;
51    if (!parse(D, Args, *I, Add, Remove, true))
52      continue;
53    (*I)->claim();
54
55    AllAdd |= expandGroups(Add);
56    AllRemove |= expandGroups(Remove);
57
58    // Avoid diagnosing any sanitizer which is disabled later.
59    Add &= ~AllRemove;
60    // At this point we have not expanded groups, so any unsupported sanitizers
61    // in Add are those which have been explicitly enabled. Diagnose them.
62    Add = filterUnsupportedKinds(TC, Add, Args, *I, /*DiagnoseErrors=*/true,
63                                 DiagnosedKinds);
64    Add = expandGroups(Add);
65    // Group expansion may have enabled a sanitizer which is disabled later.
66    Add &= ~AllRemove;
67    // Silently discard any unsupported sanitizers implicitly enabled through
68    // group expansion.
69    Add = filterUnsupportedKinds(TC, Add, Args, *I, /*DiagnoseErrors=*/false,
70                                 DiagnosedKinds);
71
72    Kind |= Add;
73  }
74
75  UbsanTrapOnError =
76    Args.hasFlag(options::OPT_fsanitize_undefined_trap_on_error,
77                 options::OPT_fno_sanitize_undefined_trap_on_error, false);
78
79  // Warn about undefined sanitizer options that require runtime support.
80  if (UbsanTrapOnError && notAllowedWithTrap()) {
81    D.Diag(diag::err_drv_argument_not_allowed_with)
82      << lastArgumentForKind(D, Args, NotAllowedWithTrap)
83      << "-fsanitize-undefined-trap-on-error";
84  }
85
86  // Only one runtime library can be used at once.
87  bool NeedsAsan = needsAsanRt();
88  bool NeedsTsan = needsTsanRt();
89  bool NeedsMsan = needsMsanRt();
90  bool NeedsLsan = needsLeakDetection();
91  if (NeedsAsan && NeedsTsan)
92    D.Diag(diag::err_drv_argument_not_allowed_with)
93      << lastArgumentForKind(D, Args, NeedsAsanRt)
94      << lastArgumentForKind(D, Args, NeedsTsanRt);
95  if (NeedsAsan && NeedsMsan)
96    D.Diag(diag::err_drv_argument_not_allowed_with)
97      << lastArgumentForKind(D, Args, NeedsAsanRt)
98      << lastArgumentForKind(D, Args, NeedsMsanRt);
99  if (NeedsTsan && NeedsMsan)
100    D.Diag(diag::err_drv_argument_not_allowed_with)
101      << lastArgumentForKind(D, Args, NeedsTsanRt)
102      << lastArgumentForKind(D, Args, NeedsMsanRt);
103  if (NeedsLsan && NeedsTsan)
104    D.Diag(diag::err_drv_argument_not_allowed_with)
105      << lastArgumentForKind(D, Args, NeedsLeakDetection)
106      << lastArgumentForKind(D, Args, NeedsTsanRt);
107  if (NeedsLsan && NeedsMsan)
108    D.Diag(diag::err_drv_argument_not_allowed_with)
109      << lastArgumentForKind(D, Args, NeedsLeakDetection)
110      << lastArgumentForKind(D, Args, NeedsMsanRt);
111  // FIXME: Currently -fsanitize=leak is silently ignored in the presence of
112  // -fsanitize=address. Perhaps it should print an error, or perhaps
113  // -f(-no)sanitize=leak should change whether leak detection is enabled by
114  // default in ASan?
115
116  // Parse -f(no-)sanitize-blacklist options.
117  if (Arg *BLArg = Args.getLastArg(options::OPT_fsanitize_blacklist,
118                                   options::OPT_fno_sanitize_blacklist)) {
119    if (BLArg->getOption().matches(options::OPT_fsanitize_blacklist)) {
120      std::string BLPath = BLArg->getValue();
121      if (llvm::sys::fs::exists(BLPath)) {
122        // Validate the blacklist format.
123        std::string BLError;
124        std::unique_ptr<llvm::SpecialCaseList> SCL(
125            llvm::SpecialCaseList::create(BLPath, BLError));
126        if (!SCL.get())
127          D.Diag(diag::err_drv_malformed_sanitizer_blacklist) << BLError;
128        else
129          BlacklistFile = BLPath;
130      } else {
131        D.Diag(diag::err_drv_no_such_file) << BLPath;
132      }
133    }
134  } else {
135    // If no -fsanitize-blacklist option is specified, try to look up for
136    // blacklist in the resource directory.
137    std::string BLPath;
138    if (getDefaultBlacklistForKind(D, Kind, BLPath) &&
139        llvm::sys::fs::exists(BLPath))
140      BlacklistFile = BLPath;
141  }
142
143  // Parse -f[no-]sanitize-memory-track-origins[=level] options.
144  if (NeedsMsan) {
145    if (Arg *A =
146            Args.getLastArg(options::OPT_fsanitize_memory_track_origins_EQ,
147                            options::OPT_fsanitize_memory_track_origins,
148                            options::OPT_fno_sanitize_memory_track_origins)) {
149      if (A->getOption().matches(options::OPT_fsanitize_memory_track_origins)) {
150        MsanTrackOrigins = 1;
151      } else if (A->getOption().matches(
152                     options::OPT_fno_sanitize_memory_track_origins)) {
153        MsanTrackOrigins = 0;
154      } else {
155        StringRef S = A->getValue();
156        if (S.getAsInteger(0, MsanTrackOrigins) || MsanTrackOrigins < 0 ||
157            MsanTrackOrigins > 2) {
158          D.Diag(diag::err_drv_invalid_value) << A->getAsString(Args) << S;
159        }
160      }
161    }
162  }
163
164  if (NeedsAsan) {
165    AsanSharedRuntime =
166        Args.hasArg(options::OPT_shared_libasan) ||
167        (TC.getTriple().getEnvironment() == llvm::Triple::Android);
168    AsanZeroBaseShadow =
169        (TC.getTriple().getEnvironment() == llvm::Triple::Android);
170  }
171}
172
173void SanitizerArgs::addArgs(const llvm::opt::ArgList &Args,
174                            llvm::opt::ArgStringList &CmdArgs) const {
175  if (!Kind)
176    return;
177  SmallString<256> SanitizeOpt("-fsanitize=");
178#define SANITIZER(NAME, ID) \
179  if (Kind & ID) \
180    SanitizeOpt += NAME ",";
181#include "clang/Basic/Sanitizers.def"
182  SanitizeOpt.pop_back();
183  CmdArgs.push_back(Args.MakeArgString(SanitizeOpt));
184  if (!BlacklistFile.empty()) {
185    SmallString<64> BlacklistOpt("-fsanitize-blacklist=");
186    BlacklistOpt += BlacklistFile;
187    CmdArgs.push_back(Args.MakeArgString(BlacklistOpt));
188  }
189
190  if (MsanTrackOrigins)
191    CmdArgs.push_back(Args.MakeArgString("-fsanitize-memory-track-origins=" +
192                                         llvm::utostr(MsanTrackOrigins)));
193
194  // Workaround for PR16386.
195  if (needsMsanRt())
196    CmdArgs.push_back(Args.MakeArgString("-fno-assume-sane-operator-new"));
197}
198
199unsigned SanitizerArgs::parse(const char *Value) {
200  unsigned ParsedKind = llvm::StringSwitch<SanitizeKind>(Value)
201#define SANITIZER(NAME, ID) .Case(NAME, ID)
202#define SANITIZER_GROUP(NAME, ID, ALIAS) .Case(NAME, ID##Group)
203#include "clang/Basic/Sanitizers.def"
204    .Default(SanitizeKind());
205  return ParsedKind;
206}
207
208unsigned SanitizerArgs::expandGroups(unsigned Kinds) {
209#define SANITIZER(NAME, ID)
210#define SANITIZER_GROUP(NAME, ID, ALIAS) if (Kinds & ID##Group) Kinds |= ID;
211#include "clang/Basic/Sanitizers.def"
212  return Kinds;
213}
214
215void SanitizerArgs::filterUnsupportedMask(const ToolChain &TC, unsigned &Kinds,
216                                          unsigned Mask,
217                                          const llvm::opt::ArgList &Args,
218                                          const llvm::opt::Arg *A,
219                                          bool DiagnoseErrors,
220                                          unsigned &DiagnosedKinds) {
221  unsigned MaskedKinds = Kinds & Mask;
222  if (!MaskedKinds)
223    return;
224  Kinds &= ~Mask;
225  // Do we have new kinds to diagnose?
226  if (DiagnoseErrors && (DiagnosedKinds & MaskedKinds) != MaskedKinds) {
227    // Only diagnose the new kinds.
228    std::string Desc =
229        describeSanitizeArg(Args, A, MaskedKinds & ~DiagnosedKinds);
230    TC.getDriver().Diag(diag::err_drv_unsupported_opt_for_target)
231        << Desc << TC.getTriple().str();
232    DiagnosedKinds |= MaskedKinds;
233  }
234}
235
236unsigned SanitizerArgs::filterUnsupportedKinds(const ToolChain &TC,
237                                               unsigned Kinds,
238                                               const llvm::opt::ArgList &Args,
239                                               const llvm::opt::Arg *A,
240                                               bool DiagnoseErrors,
241                                               unsigned &DiagnosedKinds) {
242  bool IsLinux = TC.getTriple().getOS() == llvm::Triple::Linux;
243  bool IsX86 = TC.getTriple().getArch() == llvm::Triple::x86;
244  bool IsX86_64 = TC.getTriple().getArch() == llvm::Triple::x86_64;
245  if (!(IsLinux && IsX86_64)) {
246    filterUnsupportedMask(TC, Kinds, Thread | Memory | DataFlow, Args, A,
247                          DiagnoseErrors, DiagnosedKinds);
248  }
249  if (!(IsLinux && (IsX86 || IsX86_64))) {
250    filterUnsupportedMask(TC, Kinds, Function, Args, A, DiagnoseErrors,
251                          DiagnosedKinds);
252  }
253  return Kinds;
254}
255
256unsigned SanitizerArgs::parse(const Driver &D, const llvm::opt::Arg *A,
257                              bool DiagnoseErrors) {
258  unsigned Kind = 0;
259  for (unsigned I = 0, N = A->getNumValues(); I != N; ++I) {
260    if (unsigned K = parse(A->getValue(I)))
261      Kind |= K;
262    else if (DiagnoseErrors)
263      D.Diag(diag::err_drv_unsupported_option_argument)
264        << A->getOption().getName() << A->getValue(I);
265  }
266  return Kind;
267}
268
269bool SanitizerArgs::parse(const Driver &D, const llvm::opt::ArgList &Args,
270                          const llvm::opt::Arg *A, unsigned &Add,
271                          unsigned &Remove, bool DiagnoseErrors) {
272  Add = 0;
273  Remove = 0;
274  if (A->getOption().matches(options::OPT_fsanitize_EQ)) {
275    Add = parse(D, A, DiagnoseErrors);
276  } else if (A->getOption().matches(options::OPT_fno_sanitize_EQ)) {
277    Remove = parse(D, A, DiagnoseErrors);
278  } else {
279    // Flag is not relevant to sanitizers.
280    return false;
281  }
282  return true;
283}
284
285std::string SanitizerArgs::lastArgumentForKind(const Driver &D,
286                                               const llvm::opt::ArgList &Args,
287                                               unsigned Kind) {
288  for (llvm::opt::ArgList::const_reverse_iterator I = Args.rbegin(),
289                                                  E = Args.rend();
290       I != E; ++I) {
291    unsigned Add, Remove;
292    if (parse(D, Args, *I, Add, Remove, false) &&
293        (expandGroups(Add) & Kind))
294      return describeSanitizeArg(Args, *I, Kind);
295    Kind &= ~Remove;
296  }
297  llvm_unreachable("arg list didn't provide expected value");
298}
299
300std::string SanitizerArgs::describeSanitizeArg(const llvm::opt::ArgList &Args,
301                                               const llvm::opt::Arg *A,
302                                               unsigned Mask) {
303  if (!A->getOption().matches(options::OPT_fsanitize_EQ))
304    return A->getAsString(Args);
305
306  std::string Sanitizers;
307  for (unsigned I = 0, N = A->getNumValues(); I != N; ++I) {
308    if (expandGroups(parse(A->getValue(I))) & Mask) {
309      if (!Sanitizers.empty())
310        Sanitizers += ",";
311      Sanitizers += A->getValue(I);
312    }
313  }
314
315  assert(!Sanitizers.empty() && "arg didn't provide expected value");
316  return "-fsanitize=" + Sanitizers;
317}
318
319bool SanitizerArgs::getDefaultBlacklistForKind(const Driver &D, unsigned Kind,
320                                               std::string &BLPath) {
321  const char *BlacklistFile = nullptr;
322  if (Kind & NeedsAsanRt)
323    BlacklistFile = "asan_blacklist.txt";
324  else if (Kind & NeedsMsanRt)
325    BlacklistFile = "msan_blacklist.txt";
326  else if (Kind & NeedsTsanRt)
327    BlacklistFile = "tsan_blacklist.txt";
328  else if (Kind & NeedsDfsanRt)
329    BlacklistFile = "dfsan_abilist.txt";
330
331  if (BlacklistFile) {
332    SmallString<64> Path(D.ResourceDir);
333    llvm::sys::path::append(Path, BlacklistFile);
334    BLPath = Path.str();
335    return true;
336  }
337  return false;
338}
339