1 //===--- SanitizerArgs.cpp - Arguments for sanitizer tools  ---------------===//
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 #include "clang/Driver/SanitizerArgs.h"
9 #include "ToolChains/CommonArgs.h"
10 #include "clang/Basic/Sanitizers.h"
11 #include "clang/Driver/Driver.h"
12 #include "clang/Driver/DriverDiagnostic.h"
13 #include "clang/Driver/Options.h"
14 #include "clang/Driver/ToolChain.h"
15 #include "llvm/ADT/StringExtras.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/ADT/StringSwitch.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Support/SpecialCaseList.h"
20 #include "llvm/Support/VirtualFileSystem.h"
21 #include "llvm/TargetParser/AArch64TargetParser.h"
22 #include "llvm/TargetParser/RISCVTargetParser.h"
23 #include "llvm/TargetParser/TargetParser.h"
24 #include "llvm/Transforms/Instrumentation/AddressSanitizerOptions.h"
25 #include <memory>
26 
27 using namespace clang;
28 using namespace clang::driver;
29 using namespace llvm::opt;
30 
31 static const SanitizerMask NeedsUbsanRt =
32     SanitizerKind::Undefined | SanitizerKind::Integer |
33     SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
34     SanitizerKind::CFI | SanitizerKind::FloatDivideByZero |
35     SanitizerKind::ObjCCast;
36 static const SanitizerMask NeedsUbsanCxxRt =
37     SanitizerKind::Vptr | SanitizerKind::CFI;
38 static const SanitizerMask NotAllowedWithTrap = SanitizerKind::Vptr;
39 static const SanitizerMask NotAllowedWithMinimalRuntime = SanitizerKind::Vptr;
40 static const SanitizerMask NotAllowedWithExecuteOnly =
41     SanitizerKind::Function | SanitizerKind::KCFI;
42 static const SanitizerMask RequiresPIE =
43     SanitizerKind::DataFlow | SanitizerKind::Scudo;
44 static const SanitizerMask NeedsUnwindTables =
45     SanitizerKind::Address | SanitizerKind::HWAddress | SanitizerKind::Thread |
46     SanitizerKind::Memory | SanitizerKind::DataFlow;
47 static const SanitizerMask SupportsCoverage =
48     SanitizerKind::Address | SanitizerKind::HWAddress |
49     SanitizerKind::KernelAddress | SanitizerKind::KernelHWAddress |
50     SanitizerKind::MemtagStack | SanitizerKind::MemtagHeap |
51     SanitizerKind::MemtagGlobals | SanitizerKind::Memory |
52     SanitizerKind::KernelMemory | SanitizerKind::Leak |
53     SanitizerKind::Undefined | SanitizerKind::Integer | SanitizerKind::Bounds |
54     SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
55     SanitizerKind::DataFlow | SanitizerKind::Fuzzer |
56     SanitizerKind::FuzzerNoLink | SanitizerKind::FloatDivideByZero |
57     SanitizerKind::SafeStack | SanitizerKind::ShadowCallStack |
58     SanitizerKind::Thread | SanitizerKind::ObjCCast | SanitizerKind::KCFI;
59 static const SanitizerMask RecoverableByDefault =
60     SanitizerKind::Undefined | SanitizerKind::Integer |
61     SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
62     SanitizerKind::FloatDivideByZero | SanitizerKind::ObjCCast;
63 static const SanitizerMask Unrecoverable =
64     SanitizerKind::Unreachable | SanitizerKind::Return;
65 static const SanitizerMask AlwaysRecoverable = SanitizerKind::KernelAddress |
66                                                SanitizerKind::KernelHWAddress |
67                                                SanitizerKind::KCFI;
68 static const SanitizerMask NeedsLTO = SanitizerKind::CFI;
69 static const SanitizerMask TrappingSupported =
70     (SanitizerKind::Undefined & ~SanitizerKind::Vptr) | SanitizerKind::Integer |
71     SanitizerKind::Nullability | SanitizerKind::LocalBounds |
72     SanitizerKind::CFI | SanitizerKind::FloatDivideByZero |
73     SanitizerKind::ObjCCast;
74 static const SanitizerMask TrappingDefault = SanitizerKind::CFI;
75 static const SanitizerMask CFIClasses =
76     SanitizerKind::CFIVCall | SanitizerKind::CFINVCall |
77     SanitizerKind::CFIMFCall | SanitizerKind::CFIDerivedCast |
78     SanitizerKind::CFIUnrelatedCast;
79 static const SanitizerMask CompatibleWithMinimalRuntime =
80     TrappingSupported | SanitizerKind::Scudo | SanitizerKind::ShadowCallStack |
81     SanitizerKind::MemtagStack | SanitizerKind::MemtagHeap |
82     SanitizerKind::MemtagGlobals | SanitizerKind::KCFI;
83 
84 enum CoverageFeature {
85   CoverageFunc = 1 << 0,
86   CoverageBB = 1 << 1,
87   CoverageEdge = 1 << 2,
88   CoverageIndirCall = 1 << 3,
89   CoverageTraceBB = 1 << 4, // Deprecated.
90   CoverageTraceCmp = 1 << 5,
91   CoverageTraceDiv = 1 << 6,
92   CoverageTraceGep = 1 << 7,
93   Coverage8bitCounters = 1 << 8, // Deprecated.
94   CoverageTracePC = 1 << 9,
95   CoverageTracePCGuard = 1 << 10,
96   CoverageNoPrune = 1 << 11,
97   CoverageInline8bitCounters = 1 << 12,
98   CoveragePCTable = 1 << 13,
99   CoverageStackDepth = 1 << 14,
100   CoverageInlineBoolFlag = 1 << 15,
101   CoverageTraceLoads = 1 << 16,
102   CoverageTraceStores = 1 << 17,
103   CoverageControlFlow = 1 << 18,
104 };
105 
106 enum BinaryMetadataFeature {
107   BinaryMetadataCovered = 1 << 0,
108   BinaryMetadataAtomics = 1 << 1,
109   BinaryMetadataUAR = 1 << 2,
110 };
111 
112 /// Parse a -fsanitize= or -fno-sanitize= argument's values, diagnosing any
113 /// invalid components. Returns a SanitizerMask.
114 static SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A,
115                                     bool DiagnoseErrors);
116 
117 /// Parse -f(no-)?sanitize-coverage= flag values, diagnosing any invalid
118 /// components. Returns OR of members of \c CoverageFeature enumeration.
119 static int parseCoverageFeatures(const Driver &D, const llvm::opt::Arg *A,
120                                  bool DiagnoseErrors);
121 
122 /// Parse -f(no-)?sanitize-metadata= flag values, diagnosing any invalid
123 /// components. Returns OR of members of \c BinaryMetadataFeature enumeration.
124 static int parseBinaryMetadataFeatures(const Driver &D, const llvm::opt::Arg *A,
125                                        bool DiagnoseErrors);
126 
127 /// Produce an argument string from ArgList \p Args, which shows how it
128 /// provides some sanitizer kind from \p Mask. For example, the argument list
129 /// "-fsanitize=thread,vptr -fsanitize=address" with mask \c NeedsUbsanRt
130 /// would produce "-fsanitize=vptr".
131 static std::string lastArgumentForMask(const Driver &D,
132                                        const llvm::opt::ArgList &Args,
133                                        SanitizerMask Mask);
134 
135 /// Produce an argument string from argument \p A, which shows how it provides
136 /// a value in \p Mask. For instance, the argument
137 /// "-fsanitize=address,alignment" with mask \c NeedsUbsanRt would produce
138 /// "-fsanitize=alignment".
139 static std::string describeSanitizeArg(const llvm::opt::Arg *A,
140                                        SanitizerMask Mask);
141 
142 /// Produce a string containing comma-separated names of sanitizers in \p
143 /// Sanitizers set.
144 static std::string toString(const clang::SanitizerSet &Sanitizers);
145 
146 /// Return true if an execute-only target disallows data access to code
147 /// sections.
148 static bool isExecuteOnlyTarget(const llvm::Triple &Triple,
149                                 const llvm::opt::ArgList &Args) {
150   if (Triple.isPS5())
151     return true;
152   return Args.hasFlagNoClaim(options::OPT_mexecute_only,
153                              options::OPT_mno_execute_only, false);
154 }
155 
156 static void validateSpecialCaseListFormat(const Driver &D,
157                                           std::vector<std::string> &SCLFiles,
158                                           unsigned MalformedSCLErrorDiagID,
159                                           bool DiagnoseErrors) {
160   if (SCLFiles.empty())
161     return;
162 
163   std::string BLError;
164   std::unique_ptr<llvm::SpecialCaseList> SCL(
165       llvm::SpecialCaseList::create(SCLFiles, D.getVFS(), BLError));
166   if (!SCL.get() && DiagnoseErrors)
167     D.Diag(MalformedSCLErrorDiagID) << BLError;
168 }
169 
170 static void addDefaultIgnorelists(const Driver &D, SanitizerMask Kinds,
171                                   std::vector<std::string> &IgnorelistFiles,
172                                   bool DiagnoseErrors) {
173   struct Ignorelist {
174     const char *File;
175     SanitizerMask Mask;
176   } Ignorelists[] = {{"asan_ignorelist.txt", SanitizerKind::Address},
177                      {"hwasan_ignorelist.txt", SanitizerKind::HWAddress},
178                      {"memtag_ignorelist.txt", SanitizerKind::MemTag},
179                      {"msan_ignorelist.txt", SanitizerKind::Memory},
180                      {"tsan_ignorelist.txt", SanitizerKind::Thread},
181                      {"dfsan_abilist.txt", SanitizerKind::DataFlow},
182                      {"cfi_ignorelist.txt", SanitizerKind::CFI},
183                      {"ubsan_ignorelist.txt",
184                       SanitizerKind::Undefined | SanitizerKind::Integer |
185                           SanitizerKind::Nullability |
186                           SanitizerKind::FloatDivideByZero}};
187 
188   for (auto BL : Ignorelists) {
189     if (!(Kinds & BL.Mask))
190       continue;
191 
192     clang::SmallString<64> Path(D.ResourceDir);
193     llvm::sys::path::append(Path, "share", BL.File);
194     if (D.getVFS().exists(Path))
195       IgnorelistFiles.push_back(std::string(Path.str()));
196     else if (BL.Mask == SanitizerKind::CFI && DiagnoseErrors)
197       // If cfi_ignorelist.txt cannot be found in the resource dir, driver
198       // should fail.
199       D.Diag(clang::diag::err_drv_missing_sanitizer_ignorelist) << Path;
200   }
201   validateSpecialCaseListFormat(
202       D, IgnorelistFiles, clang::diag::err_drv_malformed_sanitizer_ignorelist,
203       DiagnoseErrors);
204 }
205 
206 /// Parse -f(no-)?sanitize-(coverage-)?(allow|ignore)list argument's values,
207 /// diagnosing any invalid file paths and validating special case list format.
208 static void parseSpecialCaseListArg(const Driver &D,
209                                     const llvm::opt::ArgList &Args,
210                                     std::vector<std::string> &SCLFiles,
211                                     llvm::opt::OptSpecifier SCLOptionID,
212                                     llvm::opt::OptSpecifier NoSCLOptionID,
213                                     unsigned MalformedSCLErrorDiagID,
214                                     bool DiagnoseErrors) {
215   for (const auto *Arg : Args) {
216     // Match -fsanitize-(coverage-)?(allow|ignore)list.
217     if (Arg->getOption().matches(SCLOptionID)) {
218       Arg->claim();
219       std::string SCLPath = Arg->getValue();
220       if (D.getVFS().exists(SCLPath)) {
221         SCLFiles.push_back(SCLPath);
222       } else if (DiagnoseErrors) {
223         D.Diag(clang::diag::err_drv_no_such_file) << SCLPath;
224       }
225       // Match -fno-sanitize-ignorelist.
226     } else if (Arg->getOption().matches(NoSCLOptionID)) {
227       Arg->claim();
228       SCLFiles.clear();
229     }
230   }
231   validateSpecialCaseListFormat(D, SCLFiles, MalformedSCLErrorDiagID,
232                                 DiagnoseErrors);
233 }
234 
235 /// Sets group bits for every group that has at least one representative already
236 /// enabled in \p Kinds.
237 static SanitizerMask setGroupBits(SanitizerMask Kinds) {
238 #define SANITIZER(NAME, ID)
239 #define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
240   if (Kinds & SanitizerKind::ID)                                               \
241     Kinds |= SanitizerKind::ID##Group;
242 #include "clang/Basic/Sanitizers.def"
243   return Kinds;
244 }
245 
246 static SanitizerMask parseSanitizeTrapArgs(const Driver &D,
247                                            const llvm::opt::ArgList &Args,
248                                            bool DiagnoseErrors) {
249   SanitizerMask TrapRemove; // During the loop below, the accumulated set of
250                             // sanitizers disabled by the current sanitizer
251                             // argument or any argument after it.
252   SanitizerMask TrappingKinds;
253   SanitizerMask TrappingSupportedWithGroups = setGroupBits(TrappingSupported);
254 
255   for (const llvm::opt::Arg *Arg : llvm::reverse(Args)) {
256     if (Arg->getOption().matches(options::OPT_fsanitize_trap_EQ)) {
257       Arg->claim();
258       SanitizerMask Add = parseArgValues(D, Arg, true);
259       Add &= ~TrapRemove;
260       SanitizerMask InvalidValues = Add & ~TrappingSupportedWithGroups;
261       if (InvalidValues && DiagnoseErrors) {
262         SanitizerSet S;
263         S.Mask = InvalidValues;
264         D.Diag(diag::err_drv_unsupported_option_argument)
265             << Arg->getSpelling() << toString(S);
266       }
267       TrappingKinds |= expandSanitizerGroups(Add) & ~TrapRemove;
268     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_trap_EQ)) {
269       Arg->claim();
270       TrapRemove |=
271           expandSanitizerGroups(parseArgValues(D, Arg, DiagnoseErrors));
272     }
273   }
274 
275   // Apply default trapping behavior.
276   TrappingKinds |= TrappingDefault & ~TrapRemove;
277 
278   return TrappingKinds;
279 }
280 
281 bool SanitizerArgs::needsFuzzerInterceptors() const {
282   return needsFuzzer() && !needsAsanRt() && !needsTsanRt() && !needsMsanRt();
283 }
284 
285 bool SanitizerArgs::needsUbsanRt() const {
286   // All of these include ubsan.
287   if (needsAsanRt() || needsMsanRt() || needsHwasanRt() || needsTsanRt() ||
288       needsDfsanRt() || needsLsanRt() || needsCfiDiagRt() ||
289       (needsScudoRt() && !requiresMinimalRuntime()))
290     return false;
291 
292   return (Sanitizers.Mask & NeedsUbsanRt & ~TrapSanitizers.Mask) ||
293          CoverageFeatures;
294 }
295 
296 bool SanitizerArgs::needsCfiRt() const {
297   return !(Sanitizers.Mask & SanitizerKind::CFI & ~TrapSanitizers.Mask) &&
298          CfiCrossDso && !ImplicitCfiRuntime;
299 }
300 
301 bool SanitizerArgs::needsCfiDiagRt() const {
302   return (Sanitizers.Mask & SanitizerKind::CFI & ~TrapSanitizers.Mask) &&
303          CfiCrossDso && !ImplicitCfiRuntime;
304 }
305 
306 bool SanitizerArgs::requiresPIE() const {
307   return NeedPIE || (Sanitizers.Mask & RequiresPIE);
308 }
309 
310 bool SanitizerArgs::needsUnwindTables() const {
311   return static_cast<bool>(Sanitizers.Mask & NeedsUnwindTables);
312 }
313 
314 bool SanitizerArgs::needsLTO() const {
315   return static_cast<bool>(Sanitizers.Mask & NeedsLTO);
316 }
317 
318 SanitizerArgs::SanitizerArgs(const ToolChain &TC,
319                              const llvm::opt::ArgList &Args,
320                              bool DiagnoseErrors) {
321   SanitizerMask AllRemove;      // During the loop below, the accumulated set of
322                                 // sanitizers disabled by the current sanitizer
323                                 // argument or any argument after it.
324   SanitizerMask AllAddedKinds;  // Mask of all sanitizers ever enabled by
325                                 // -fsanitize= flags (directly or via group
326                                 // expansion), some of which may be disabled
327                                 // later. Used to carefully prune
328                                 // unused-argument diagnostics.
329   SanitizerMask DiagnosedKinds; // All Kinds we have diagnosed up to now.
330                                 // Used to deduplicate diagnostics.
331   SanitizerMask Kinds;
332   const SanitizerMask Supported = setGroupBits(TC.getSupportedSanitizers());
333 
334   CfiCrossDso = Args.hasFlag(options::OPT_fsanitize_cfi_cross_dso,
335                              options::OPT_fno_sanitize_cfi_cross_dso, false);
336 
337   ToolChain::RTTIMode RTTIMode = TC.getRTTIMode();
338 
339   const Driver &D = TC.getDriver();
340   SanitizerMask TrappingKinds = parseSanitizeTrapArgs(D, Args, DiagnoseErrors);
341   SanitizerMask InvalidTrappingKinds = TrappingKinds & NotAllowedWithTrap;
342 
343   MinimalRuntime =
344       Args.hasFlag(options::OPT_fsanitize_minimal_runtime,
345                    options::OPT_fno_sanitize_minimal_runtime, MinimalRuntime);
346 
347   // The object size sanitizer should not be enabled at -O0.
348   Arg *OptLevel = Args.getLastArg(options::OPT_O_Group);
349   bool RemoveObjectSizeAtO0 =
350       !OptLevel || OptLevel->getOption().matches(options::OPT_O0);
351 
352   for (const llvm::opt::Arg *Arg : llvm::reverse(Args)) {
353     if (Arg->getOption().matches(options::OPT_fsanitize_EQ)) {
354       Arg->claim();
355       SanitizerMask Add = parseArgValues(D, Arg, DiagnoseErrors);
356 
357       if (RemoveObjectSizeAtO0) {
358         AllRemove |= SanitizerKind::ObjectSize;
359 
360         // The user explicitly enabled the object size sanitizer. Warn
361         // that this does nothing at -O0.
362         if ((Add & SanitizerKind::ObjectSize) && DiagnoseErrors)
363           D.Diag(diag::warn_drv_object_size_disabled_O0)
364               << Arg->getAsString(Args);
365       }
366 
367       AllAddedKinds |= expandSanitizerGroups(Add);
368 
369       // Avoid diagnosing any sanitizer which is disabled later.
370       Add &= ~AllRemove;
371       // At this point we have not expanded groups, so any unsupported
372       // sanitizers in Add are those which have been explicitly enabled.
373       // Diagnose them.
374       if (SanitizerMask KindsToDiagnose =
375               Add & InvalidTrappingKinds & ~DiagnosedKinds) {
376         if (DiagnoseErrors) {
377           std::string Desc = describeSanitizeArg(Arg, KindsToDiagnose);
378           D.Diag(diag::err_drv_argument_not_allowed_with)
379               << Desc << "-fsanitize-trap=undefined";
380         }
381         DiagnosedKinds |= KindsToDiagnose;
382       }
383       Add &= ~InvalidTrappingKinds;
384 
385       if (MinimalRuntime) {
386         if (SanitizerMask KindsToDiagnose =
387                 Add & NotAllowedWithMinimalRuntime & ~DiagnosedKinds) {
388           if (DiagnoseErrors) {
389             std::string Desc = describeSanitizeArg(Arg, KindsToDiagnose);
390             D.Diag(diag::err_drv_argument_not_allowed_with)
391                 << Desc << "-fsanitize-minimal-runtime";
392           }
393           DiagnosedKinds |= KindsToDiagnose;
394         }
395         Add &= ~NotAllowedWithMinimalRuntime;
396       }
397 
398       if (llvm::opt::Arg *A = Args.getLastArg(options::OPT_mcmodel_EQ)) {
399         StringRef CM = A->getValue();
400         if (CM != "small" &&
401             (Add & SanitizerKind::Function & ~DiagnosedKinds)) {
402           if (DiagnoseErrors)
403             D.Diag(diag::err_drv_argument_only_allowed_with)
404                 << "-fsanitize=function"
405                 << "-mcmodel=small";
406           Add &= ~SanitizerKind::Function;
407           DiagnosedKinds |= SanitizerKind::Function;
408         }
409       }
410       // -fsanitize=function and -fsanitize=kcfi instrument indirect function
411       // calls to load a type hash before the function label. Therefore, an
412       // execute-only target doesn't support the function and kcfi sanitizers.
413       const llvm::Triple &Triple = TC.getTriple();
414       if (isExecuteOnlyTarget(Triple, Args)) {
415         if (SanitizerMask KindsToDiagnose =
416                 Add & NotAllowedWithExecuteOnly & ~DiagnosedKinds) {
417           if (DiagnoseErrors) {
418             std::string Desc = describeSanitizeArg(Arg, KindsToDiagnose);
419             D.Diag(diag::err_drv_argument_not_allowed_with)
420                 << Desc << Triple.str();
421           }
422           DiagnosedKinds |= KindsToDiagnose;
423         }
424         Add &= ~NotAllowedWithExecuteOnly;
425       }
426 
427       // FIXME: Make CFI on member function calls compatible with cross-DSO CFI.
428       // There are currently two problems:
429       // - Virtual function call checks need to pass a pointer to the function
430       //   address to llvm.type.test and a pointer to the address point to the
431       //   diagnostic function. Currently we pass the same pointer to both
432       //   places.
433       // - Non-virtual function call checks may need to check multiple type
434       //   identifiers.
435       // Fixing both of those may require changes to the cross-DSO CFI
436       // interface.
437       if (CfiCrossDso && (Add & SanitizerKind::CFIMFCall & ~DiagnosedKinds)) {
438         if (DiagnoseErrors)
439           D.Diag(diag::err_drv_argument_not_allowed_with)
440               << "-fsanitize=cfi-mfcall"
441               << "-fsanitize-cfi-cross-dso";
442         Add &= ~SanitizerKind::CFIMFCall;
443         DiagnosedKinds |= SanitizerKind::CFIMFCall;
444       }
445 
446       if (SanitizerMask KindsToDiagnose = Add & ~Supported & ~DiagnosedKinds) {
447         if (DiagnoseErrors) {
448           std::string Desc = describeSanitizeArg(Arg, KindsToDiagnose);
449           D.Diag(diag::err_drv_unsupported_opt_for_target)
450               << Desc << TC.getTriple().str();
451         }
452         DiagnosedKinds |= KindsToDiagnose;
453       }
454       Add &= Supported;
455 
456       // Test for -fno-rtti + explicit -fsanitizer=vptr before expanding groups
457       // so we don't error out if -fno-rtti and -fsanitize=undefined were
458       // passed.
459       if ((Add & SanitizerKind::Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
460         if (const llvm::opt::Arg *NoRTTIArg = TC.getRTTIArg()) {
461           assert(NoRTTIArg->getOption().matches(options::OPT_fno_rtti) &&
462                  "RTTI disabled without -fno-rtti option?");
463           // The user explicitly passed -fno-rtti with -fsanitize=vptr, but
464           // the vptr sanitizer requires RTTI, so this is a user error.
465           if (DiagnoseErrors)
466             D.Diag(diag::err_drv_argument_not_allowed_with)
467                 << "-fsanitize=vptr" << NoRTTIArg->getAsString(Args);
468         } else {
469           // The vptr sanitizer requires RTTI, but RTTI is disabled (by
470           // default). Warn that the vptr sanitizer is being disabled.
471           if (DiagnoseErrors)
472             D.Diag(diag::warn_drv_disabling_vptr_no_rtti_default);
473         }
474 
475         // Take out the Vptr sanitizer from the enabled sanitizers
476         AllRemove |= SanitizerKind::Vptr;
477       }
478 
479       Add = expandSanitizerGroups(Add);
480       // Group expansion may have enabled a sanitizer which is disabled later.
481       Add &= ~AllRemove;
482       // Silently discard any unsupported sanitizers implicitly enabled through
483       // group expansion.
484       Add &= ~InvalidTrappingKinds;
485       if (MinimalRuntime) {
486         Add &= ~NotAllowedWithMinimalRuntime;
487       }
488       // NotAllowedWithExecuteOnly is silently discarded on an execute-only
489       // target if implicitly enabled through group expansion.
490       if (isExecuteOnlyTarget(Triple, Args))
491         Add &= ~NotAllowedWithExecuteOnly;
492       if (CfiCrossDso)
493         Add &= ~SanitizerKind::CFIMFCall;
494       Add &= Supported;
495 
496       if (Add & SanitizerKind::Fuzzer)
497         Add |= SanitizerKind::FuzzerNoLink;
498 
499       // Enable coverage if the fuzzing flag is set.
500       if (Add & SanitizerKind::FuzzerNoLink) {
501         CoverageFeatures |= CoverageInline8bitCounters | CoverageIndirCall |
502                             CoverageTraceCmp | CoveragePCTable;
503         // Due to TLS differences, stack depth tracking is only enabled on Linux
504         if (TC.getTriple().isOSLinux())
505           CoverageFeatures |= CoverageStackDepth;
506       }
507 
508       Kinds |= Add;
509     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_EQ)) {
510       Arg->claim();
511       SanitizerMask Remove = parseArgValues(D, Arg, DiagnoseErrors);
512       AllRemove |= expandSanitizerGroups(Remove);
513     }
514   }
515 
516   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
517       std::make_pair(SanitizerKind::Address,
518                      SanitizerKind::Thread | SanitizerKind::Memory),
519       std::make_pair(SanitizerKind::Thread, SanitizerKind::Memory),
520       std::make_pair(SanitizerKind::Leak,
521                      SanitizerKind::Thread | SanitizerKind::Memory),
522       std::make_pair(SanitizerKind::KernelAddress,
523                      SanitizerKind::Address | SanitizerKind::Leak |
524                          SanitizerKind::Thread | SanitizerKind::Memory),
525       std::make_pair(SanitizerKind::HWAddress,
526                      SanitizerKind::Address | SanitizerKind::Thread |
527                          SanitizerKind::Memory | SanitizerKind::KernelAddress),
528       std::make_pair(SanitizerKind::Scudo,
529                      SanitizerKind::Address | SanitizerKind::HWAddress |
530                          SanitizerKind::Leak | SanitizerKind::Thread |
531                          SanitizerKind::Memory | SanitizerKind::KernelAddress),
532       std::make_pair(SanitizerKind::SafeStack,
533                      (TC.getTriple().isOSFuchsia() ? SanitizerMask()
534                                                    : SanitizerKind::Leak) |
535                          SanitizerKind::Address | SanitizerKind::HWAddress |
536                          SanitizerKind::Thread | SanitizerKind::Memory |
537                          SanitizerKind::KernelAddress),
538       std::make_pair(SanitizerKind::KernelHWAddress,
539                      SanitizerKind::Address | SanitizerKind::HWAddress |
540                          SanitizerKind::Leak | SanitizerKind::Thread |
541                          SanitizerKind::Memory | SanitizerKind::KernelAddress |
542                          SanitizerKind::SafeStack),
543       std::make_pair(SanitizerKind::KernelMemory,
544                      SanitizerKind::Address | SanitizerKind::HWAddress |
545                          SanitizerKind::Leak | SanitizerKind::Thread |
546                          SanitizerKind::Memory | SanitizerKind::KernelAddress |
547                          SanitizerKind::Scudo | SanitizerKind::SafeStack),
548       std::make_pair(SanitizerKind::MemTag,
549                      SanitizerKind::Address | SanitizerKind::KernelAddress |
550                          SanitizerKind::HWAddress |
551                          SanitizerKind::KernelHWAddress),
552       std::make_pair(SanitizerKind::KCFI, SanitizerKind::Function)};
553   // Enable toolchain specific default sanitizers if not explicitly disabled.
554   SanitizerMask Default = TC.getDefaultSanitizers() & ~AllRemove;
555 
556   // Disable default sanitizers that are incompatible with explicitly requested
557   // ones.
558   for (auto G : IncompatibleGroups) {
559     SanitizerMask Group = G.first;
560     if ((Default & Group) && (Kinds & G.second))
561       Default &= ~Group;
562   }
563 
564   Kinds |= Default;
565 
566   // We disable the vptr sanitizer if it was enabled by group expansion but RTTI
567   // is disabled.
568   if ((Kinds & SanitizerKind::Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
569     Kinds &= ~SanitizerKind::Vptr;
570   }
571 
572   // Check that LTO is enabled if we need it.
573   if ((Kinds & NeedsLTO) && !D.isUsingLTO() && DiagnoseErrors) {
574     D.Diag(diag::err_drv_argument_only_allowed_with)
575         << lastArgumentForMask(D, Args, Kinds & NeedsLTO) << "-flto";
576   }
577 
578   if ((Kinds & SanitizerKind::ShadowCallStack) && TC.getTriple().isAArch64() &&
579       !llvm::AArch64::isX18ReservedByDefault(TC.getTriple()) &&
580       !Args.hasArg(options::OPT_ffixed_x18) && DiagnoseErrors) {
581     D.Diag(diag::err_drv_argument_only_allowed_with)
582         << lastArgumentForMask(D, Args, Kinds & SanitizerKind::ShadowCallStack)
583         << "-ffixed-x18";
584   }
585 
586   // Report error if there are non-trapping sanitizers that require
587   // c++abi-specific  parts of UBSan runtime, and they are not provided by the
588   // toolchain. We don't have a good way to check the latter, so we just
589   // check if the toolchan supports vptr.
590   if (~Supported & SanitizerKind::Vptr) {
591     SanitizerMask KindsToDiagnose = Kinds & ~TrappingKinds & NeedsUbsanCxxRt;
592     // The runtime library supports the Microsoft C++ ABI, but only well enough
593     // for CFI. FIXME: Remove this once we support vptr on Windows.
594     if (TC.getTriple().isOSWindows())
595       KindsToDiagnose &= ~SanitizerKind::CFI;
596     if (KindsToDiagnose) {
597       SanitizerSet S;
598       S.Mask = KindsToDiagnose;
599       if (DiagnoseErrors)
600         D.Diag(diag::err_drv_unsupported_opt_for_target)
601             << ("-fno-sanitize-trap=" + toString(S)) << TC.getTriple().str();
602       Kinds &= ~KindsToDiagnose;
603     }
604   }
605 
606   // Warn about incompatible groups of sanitizers.
607   for (auto G : IncompatibleGroups) {
608     SanitizerMask Group = G.first;
609     if (Kinds & Group) {
610       if (SanitizerMask Incompatible = Kinds & G.second) {
611         if (DiagnoseErrors)
612           D.Diag(clang::diag::err_drv_argument_not_allowed_with)
613               << lastArgumentForMask(D, Args, Group)
614               << lastArgumentForMask(D, Args, Incompatible);
615         Kinds &= ~Incompatible;
616       }
617     }
618   }
619   // FIXME: Currently -fsanitize=leak is silently ignored in the presence of
620   // -fsanitize=address. Perhaps it should print an error, or perhaps
621   // -f(-no)sanitize=leak should change whether leak detection is enabled by
622   // default in ASan?
623 
624   // Parse -f(no-)?sanitize-recover flags.
625   SanitizerMask RecoverableKinds = RecoverableByDefault | AlwaysRecoverable;
626   SanitizerMask DiagnosedUnrecoverableKinds;
627   SanitizerMask DiagnosedAlwaysRecoverableKinds;
628   for (const auto *Arg : Args) {
629     if (Arg->getOption().matches(options::OPT_fsanitize_recover_EQ)) {
630       SanitizerMask Add = parseArgValues(D, Arg, DiagnoseErrors);
631       // Report error if user explicitly tries to recover from unrecoverable
632       // sanitizer.
633       if (SanitizerMask KindsToDiagnose =
634               Add & Unrecoverable & ~DiagnosedUnrecoverableKinds) {
635         SanitizerSet SetToDiagnose;
636         SetToDiagnose.Mask |= KindsToDiagnose;
637         if (DiagnoseErrors)
638           D.Diag(diag::err_drv_unsupported_option_argument)
639               << Arg->getSpelling() << toString(SetToDiagnose);
640         DiagnosedUnrecoverableKinds |= KindsToDiagnose;
641       }
642       RecoverableKinds |= expandSanitizerGroups(Add);
643       Arg->claim();
644     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_recover_EQ)) {
645       SanitizerMask Remove = parseArgValues(D, Arg, DiagnoseErrors);
646       // Report error if user explicitly tries to disable recovery from
647       // always recoverable sanitizer.
648       if (SanitizerMask KindsToDiagnose =
649               Remove & AlwaysRecoverable & ~DiagnosedAlwaysRecoverableKinds) {
650         SanitizerSet SetToDiagnose;
651         SetToDiagnose.Mask |= KindsToDiagnose;
652         if (DiagnoseErrors)
653           D.Diag(diag::err_drv_unsupported_option_argument)
654               << Arg->getSpelling() << toString(SetToDiagnose);
655         DiagnosedAlwaysRecoverableKinds |= KindsToDiagnose;
656       }
657       RecoverableKinds &= ~expandSanitizerGroups(Remove);
658       Arg->claim();
659     }
660   }
661   RecoverableKinds &= Kinds;
662   RecoverableKinds &= ~Unrecoverable;
663 
664   TrappingKinds &= Kinds;
665   RecoverableKinds &= ~TrappingKinds;
666 
667   // Setup ignorelist files.
668   // Add default ignorelist from resource directory for activated sanitizers,
669   // and validate special case lists format.
670   if (!Args.hasArgNoClaim(options::OPT_fno_sanitize_ignorelist))
671     addDefaultIgnorelists(D, Kinds, SystemIgnorelistFiles, DiagnoseErrors);
672 
673   // Parse -f(no-)?sanitize-ignorelist options.
674   // This also validates special case lists format.
675   parseSpecialCaseListArg(
676       D, Args, UserIgnorelistFiles, options::OPT_fsanitize_ignorelist_EQ,
677       options::OPT_fno_sanitize_ignorelist,
678       clang::diag::err_drv_malformed_sanitizer_ignorelist, DiagnoseErrors);
679 
680   // Parse -f[no-]sanitize-memory-track-origins[=level] options.
681   if (AllAddedKinds & SanitizerKind::Memory) {
682     if (Arg *A =
683             Args.getLastArg(options::OPT_fsanitize_memory_track_origins_EQ,
684                             options::OPT_fno_sanitize_memory_track_origins)) {
685       if (!A->getOption().matches(
686               options::OPT_fno_sanitize_memory_track_origins)) {
687         StringRef S = A->getValue();
688         if (S.getAsInteger(0, MsanTrackOrigins) || MsanTrackOrigins < 0 ||
689             MsanTrackOrigins > 2) {
690           if (DiagnoseErrors)
691             D.Diag(clang::diag::err_drv_invalid_value)
692                 << A->getAsString(Args) << S;
693         }
694       }
695     }
696     MsanUseAfterDtor = Args.hasFlag(
697         options::OPT_fsanitize_memory_use_after_dtor,
698         options::OPT_fno_sanitize_memory_use_after_dtor, MsanUseAfterDtor);
699     MsanParamRetval = Args.hasFlag(
700         options::OPT_fsanitize_memory_param_retval,
701         options::OPT_fno_sanitize_memory_param_retval, MsanParamRetval);
702     NeedPIE |= !(TC.getTriple().isOSLinux() &&
703                  TC.getTriple().getArch() == llvm::Triple::x86_64);
704   } else if (AllAddedKinds & SanitizerKind::KernelMemory) {
705     MsanUseAfterDtor = false;
706     MsanParamRetval = Args.hasFlag(
707         options::OPT_fsanitize_memory_param_retval,
708         options::OPT_fno_sanitize_memory_param_retval, MsanParamRetval);
709   } else {
710     MsanUseAfterDtor = false;
711     MsanParamRetval = false;
712   }
713 
714   if (AllAddedKinds & SanitizerKind::MemTag) {
715     StringRef S =
716         Args.getLastArgValue(options::OPT_fsanitize_memtag_mode_EQ, "sync");
717     if (S == "async" || S == "sync") {
718       MemtagMode = S.str();
719     } else {
720       D.Diag(clang::diag::err_drv_invalid_value_with_suggestion)
721           << "-fsanitize-memtag-mode=" << S << "{async, sync}";
722       MemtagMode = "sync";
723     }
724   }
725 
726   if (AllAddedKinds & SanitizerKind::Thread) {
727     TsanMemoryAccess = Args.hasFlag(
728         options::OPT_fsanitize_thread_memory_access,
729         options::OPT_fno_sanitize_thread_memory_access, TsanMemoryAccess);
730     TsanFuncEntryExit = Args.hasFlag(
731         options::OPT_fsanitize_thread_func_entry_exit,
732         options::OPT_fno_sanitize_thread_func_entry_exit, TsanFuncEntryExit);
733     TsanAtomics =
734         Args.hasFlag(options::OPT_fsanitize_thread_atomics,
735                      options::OPT_fno_sanitize_thread_atomics, TsanAtomics);
736   }
737 
738   if (AllAddedKinds & SanitizerKind::CFI) {
739     // Without PIE, external function address may resolve to a PLT record, which
740     // can not be verified by the target module.
741     NeedPIE |= CfiCrossDso;
742     CfiICallGeneralizePointers =
743         Args.hasArg(options::OPT_fsanitize_cfi_icall_generalize_pointers);
744 
745     CfiICallNormalizeIntegers =
746         Args.hasArg(options::OPT_fsanitize_cfi_icall_normalize_integers);
747 
748     if (CfiCrossDso && CfiICallGeneralizePointers && DiagnoseErrors)
749       D.Diag(diag::err_drv_argument_not_allowed_with)
750           << "-fsanitize-cfi-cross-dso"
751           << "-fsanitize-cfi-icall-generalize-pointers";
752 
753     CfiCanonicalJumpTables =
754         Args.hasFlag(options::OPT_fsanitize_cfi_canonical_jump_tables,
755                      options::OPT_fno_sanitize_cfi_canonical_jump_tables, true);
756   }
757 
758   if (AllAddedKinds & SanitizerKind::KCFI) {
759     CfiICallNormalizeIntegers =
760         Args.hasArg(options::OPT_fsanitize_cfi_icall_normalize_integers);
761 
762     if (AllAddedKinds & SanitizerKind::CFI && DiagnoseErrors)
763       D.Diag(diag::err_drv_argument_not_allowed_with)
764           << "-fsanitize=kcfi"
765           << lastArgumentForMask(D, Args, SanitizerKind::CFI);
766   }
767 
768   Stats = Args.hasFlag(options::OPT_fsanitize_stats,
769                        options::OPT_fno_sanitize_stats, false);
770 
771   if (MinimalRuntime) {
772     SanitizerMask IncompatibleMask =
773         Kinds & ~setGroupBits(CompatibleWithMinimalRuntime);
774     if (IncompatibleMask && DiagnoseErrors)
775       D.Diag(clang::diag::err_drv_argument_not_allowed_with)
776           << "-fsanitize-minimal-runtime"
777           << lastArgumentForMask(D, Args, IncompatibleMask);
778 
779     SanitizerMask NonTrappingCfi = Kinds & SanitizerKind::CFI & ~TrappingKinds;
780     if (NonTrappingCfi && DiagnoseErrors)
781       D.Diag(clang::diag::err_drv_argument_only_allowed_with)
782           << "fsanitize-minimal-runtime"
783           << "fsanitize-trap=cfi";
784   }
785 
786   // Parse -f(no-)?sanitize-coverage flags if coverage is supported by the
787   // enabled sanitizers.
788   for (const auto *Arg : Args) {
789     if (Arg->getOption().matches(options::OPT_fsanitize_coverage)) {
790       int LegacySanitizeCoverage;
791       if (Arg->getNumValues() == 1 &&
792           !StringRef(Arg->getValue(0))
793                .getAsInteger(0, LegacySanitizeCoverage)) {
794         CoverageFeatures = 0;
795         Arg->claim();
796         if (LegacySanitizeCoverage != 0 && DiagnoseErrors) {
797           D.Diag(diag::warn_drv_deprecated_arg)
798               << Arg->getAsString(Args) << "-fsanitize-coverage=trace-pc-guard";
799         }
800         continue;
801       }
802       CoverageFeatures |= parseCoverageFeatures(D, Arg, DiagnoseErrors);
803 
804       // Disable coverage and not claim the flags if there is at least one
805       // non-supporting sanitizer.
806       if (!(AllAddedKinds & ~AllRemove & ~setGroupBits(SupportsCoverage))) {
807         Arg->claim();
808       } else {
809         CoverageFeatures = 0;
810       }
811     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_coverage)) {
812       Arg->claim();
813       CoverageFeatures &= ~parseCoverageFeatures(D, Arg, DiagnoseErrors);
814     }
815   }
816   // Choose at most one coverage type: function, bb, or edge.
817   if (DiagnoseErrors) {
818     if ((CoverageFeatures & CoverageFunc) && (CoverageFeatures & CoverageBB))
819       D.Diag(clang::diag::err_drv_argument_not_allowed_with)
820           << "-fsanitize-coverage=func"
821           << "-fsanitize-coverage=bb";
822     if ((CoverageFeatures & CoverageFunc) && (CoverageFeatures & CoverageEdge))
823       D.Diag(clang::diag::err_drv_argument_not_allowed_with)
824           << "-fsanitize-coverage=func"
825           << "-fsanitize-coverage=edge";
826     if ((CoverageFeatures & CoverageBB) && (CoverageFeatures & CoverageEdge))
827       D.Diag(clang::diag::err_drv_argument_not_allowed_with)
828           << "-fsanitize-coverage=bb"
829           << "-fsanitize-coverage=edge";
830     // Basic block tracing and 8-bit counters require some type of coverage
831     // enabled.
832     if (CoverageFeatures & CoverageTraceBB)
833       D.Diag(clang::diag::warn_drv_deprecated_arg)
834           << "-fsanitize-coverage=trace-bb"
835           << "-fsanitize-coverage=trace-pc-guard";
836     if (CoverageFeatures & Coverage8bitCounters)
837       D.Diag(clang::diag::warn_drv_deprecated_arg)
838           << "-fsanitize-coverage=8bit-counters"
839           << "-fsanitize-coverage=trace-pc-guard";
840   }
841 
842   int InsertionPointTypes = CoverageFunc | CoverageBB | CoverageEdge;
843   int InstrumentationTypes = CoverageTracePC | CoverageTracePCGuard |
844                              CoverageInline8bitCounters | CoverageTraceLoads |
845                              CoverageTraceStores | CoverageInlineBoolFlag |
846                              CoverageControlFlow;
847   if ((CoverageFeatures & InsertionPointTypes) &&
848       !(CoverageFeatures & InstrumentationTypes) && DiagnoseErrors) {
849     D.Diag(clang::diag::warn_drv_deprecated_arg)
850         << "-fsanitize-coverage=[func|bb|edge]"
851         << "-fsanitize-coverage=[func|bb|edge],[trace-pc-guard|trace-pc],["
852            "control-flow]";
853   }
854 
855   // trace-pc w/o func/bb/edge implies edge.
856   if (!(CoverageFeatures & InsertionPointTypes)) {
857     if (CoverageFeatures &
858         (CoverageTracePC | CoverageTracePCGuard | CoverageInline8bitCounters |
859          CoverageInlineBoolFlag | CoverageControlFlow))
860       CoverageFeatures |= CoverageEdge;
861 
862     if (CoverageFeatures & CoverageStackDepth)
863       CoverageFeatures |= CoverageFunc;
864   }
865 
866   // Parse -fsanitize-coverage-(allow|ignore)list options if coverage enabled.
867   // This also validates special case lists format.
868   // Here, OptSpecifier() acts as a never-matching command-line argument.
869   // So, there is no way to clear coverage lists but you can append to them.
870   if (CoverageFeatures) {
871     parseSpecialCaseListArg(
872         D, Args, CoverageAllowlistFiles,
873         options::OPT_fsanitize_coverage_allowlist, OptSpecifier(),
874         clang::diag::err_drv_malformed_sanitizer_coverage_allowlist,
875         DiagnoseErrors);
876     parseSpecialCaseListArg(
877         D, Args, CoverageIgnorelistFiles,
878         options::OPT_fsanitize_coverage_ignorelist, OptSpecifier(),
879         clang::diag::err_drv_malformed_sanitizer_coverage_ignorelist,
880         DiagnoseErrors);
881   }
882 
883   // Parse -f(no-)?sanitize-metadata.
884   for (const auto *Arg :
885        Args.filtered(options::OPT_fexperimental_sanitize_metadata_EQ,
886                      options::OPT_fno_experimental_sanitize_metadata_EQ)) {
887     if (Arg->getOption().matches(
888             options::OPT_fexperimental_sanitize_metadata_EQ)) {
889       Arg->claim();
890       BinaryMetadataFeatures |=
891           parseBinaryMetadataFeatures(D, Arg, DiagnoseErrors);
892     } else {
893       Arg->claim();
894       BinaryMetadataFeatures &=
895           ~parseBinaryMetadataFeatures(D, Arg, DiagnoseErrors);
896     }
897   }
898 
899   // Parse -fsanitize-metadata-ignorelist option if enabled.
900   if (BinaryMetadataFeatures) {
901     parseSpecialCaseListArg(
902         D, Args, BinaryMetadataIgnorelistFiles,
903         options::OPT_fexperimental_sanitize_metadata_ignorelist_EQ,
904         OptSpecifier(), // Cannot clear ignore list, only append.
905         clang::diag::err_drv_malformed_sanitizer_metadata_ignorelist,
906         DiagnoseErrors);
907   }
908 
909   SharedRuntime =
910       Args.hasFlag(options::OPT_shared_libsan, options::OPT_static_libsan,
911                    TC.getTriple().isAndroid() || TC.getTriple().isOSFuchsia() ||
912                        TC.getTriple().isOSDarwin());
913 
914   ImplicitCfiRuntime = TC.getTriple().isAndroid();
915 
916   if (AllAddedKinds & SanitizerKind::Address) {
917     NeedPIE |= TC.getTriple().isOSFuchsia();
918     if (Arg *A =
919             Args.getLastArg(options::OPT_fsanitize_address_field_padding)) {
920       StringRef S = A->getValue();
921       // Legal values are 0 and 1, 2, but in future we may add more levels.
922       if ((S.getAsInteger(0, AsanFieldPadding) || AsanFieldPadding < 0 ||
923            AsanFieldPadding > 2) &&
924           DiagnoseErrors) {
925         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
926       }
927     }
928 
929     if (Arg *WindowsDebugRTArg =
930             Args.getLastArg(options::OPT__SLASH_MTd, options::OPT__SLASH_MT,
931                             options::OPT__SLASH_MDd, options::OPT__SLASH_MD,
932                             options::OPT__SLASH_LDd, options::OPT__SLASH_LD)) {
933       switch (WindowsDebugRTArg->getOption().getID()) {
934       case options::OPT__SLASH_MTd:
935       case options::OPT__SLASH_MDd:
936       case options::OPT__SLASH_LDd:
937         if (DiagnoseErrors) {
938           D.Diag(clang::diag::err_drv_argument_not_allowed_with)
939               << WindowsDebugRTArg->getAsString(Args)
940               << lastArgumentForMask(D, Args, SanitizerKind::Address);
941           D.Diag(clang::diag::note_drv_address_sanitizer_debug_runtime);
942         }
943       }
944     }
945 
946     StableABI = Args.hasFlag(options::OPT_fsanitize_stable_abi,
947                              options::OPT_fno_sanitize_stable_abi, false);
948 
949     AsanUseAfterScope = Args.hasFlag(
950         options::OPT_fsanitize_address_use_after_scope,
951         options::OPT_fno_sanitize_address_use_after_scope, AsanUseAfterScope);
952 
953     AsanPoisonCustomArrayCookie = Args.hasFlag(
954         options::OPT_fsanitize_address_poison_custom_array_cookie,
955         options::OPT_fno_sanitize_address_poison_custom_array_cookie,
956         AsanPoisonCustomArrayCookie);
957 
958     AsanOutlineInstrumentation =
959         Args.hasFlag(options::OPT_fsanitize_address_outline_instrumentation,
960                      options::OPT_fno_sanitize_address_outline_instrumentation,
961                      AsanOutlineInstrumentation);
962 
963     AsanGlobalsDeadStripping = Args.hasFlag(
964         options::OPT_fsanitize_address_globals_dead_stripping,
965         options::OPT_fno_sanitize_address_globals_dead_stripping, true);
966 
967     // Enable ODR indicators which allow better handling of mixed instrumented
968     // and uninstrumented globals. Disable them for Windows where weak odr
969     // indicators (.weak.__odr_asan_gen*) may cause multiple definition linker
970     // errors in the absence of -lldmingw.
971     AsanUseOdrIndicator =
972         Args.hasFlag(options::OPT_fsanitize_address_use_odr_indicator,
973                      options::OPT_fno_sanitize_address_use_odr_indicator,
974                      !TC.getTriple().isOSWindows());
975 
976     if (AllAddedKinds & SanitizerKind::PointerCompare & ~AllRemove) {
977       AsanInvalidPointerCmp = true;
978     }
979 
980     if (AllAddedKinds & SanitizerKind::PointerSubtract & ~AllRemove) {
981       AsanInvalidPointerSub = true;
982     }
983 
984     if (TC.getTriple().isOSDarwin() &&
985         (Args.hasArg(options::OPT_mkernel) ||
986          Args.hasArg(options::OPT_fapple_kext))) {
987       AsanDtorKind = llvm::AsanDtorKind::None;
988     }
989 
990     if (const auto *Arg =
991             Args.getLastArg(options::OPT_sanitize_address_destructor_EQ)) {
992       auto parsedAsanDtorKind = AsanDtorKindFromString(Arg->getValue());
993       if (parsedAsanDtorKind == llvm::AsanDtorKind::Invalid && DiagnoseErrors) {
994         TC.getDriver().Diag(clang::diag::err_drv_unsupported_option_argument)
995             << Arg->getSpelling() << Arg->getValue();
996       }
997       AsanDtorKind = parsedAsanDtorKind;
998     }
999 
1000     if (const auto *Arg = Args.getLastArg(
1001             options::OPT_sanitize_address_use_after_return_EQ)) {
1002       auto parsedAsanUseAfterReturn =
1003           AsanDetectStackUseAfterReturnModeFromString(Arg->getValue());
1004       if (parsedAsanUseAfterReturn ==
1005               llvm::AsanDetectStackUseAfterReturnMode::Invalid &&
1006           DiagnoseErrors) {
1007         TC.getDriver().Diag(clang::diag::err_drv_unsupported_option_argument)
1008             << Arg->getSpelling() << Arg->getValue();
1009       }
1010       AsanUseAfterReturn = parsedAsanUseAfterReturn;
1011     }
1012 
1013   } else {
1014     AsanUseAfterScope = false;
1015     // -fsanitize=pointer-compare/pointer-subtract requires -fsanitize=address.
1016     SanitizerMask DetectInvalidPointerPairs =
1017         SanitizerKind::PointerCompare | SanitizerKind::PointerSubtract;
1018     if ((AllAddedKinds & DetectInvalidPointerPairs & ~AllRemove) &&
1019         DiagnoseErrors) {
1020       TC.getDriver().Diag(clang::diag::err_drv_argument_only_allowed_with)
1021           << lastArgumentForMask(D, Args,
1022                                  SanitizerKind::PointerCompare |
1023                                      SanitizerKind::PointerSubtract)
1024           << "-fsanitize=address";
1025     }
1026   }
1027 
1028   if (AllAddedKinds & SanitizerKind::HWAddress) {
1029     if (Arg *HwasanAbiArg =
1030             Args.getLastArg(options::OPT_fsanitize_hwaddress_abi_EQ)) {
1031       HwasanAbi = HwasanAbiArg->getValue();
1032       if (HwasanAbi != "platform" && HwasanAbi != "interceptor" &&
1033           DiagnoseErrors)
1034         D.Diag(clang::diag::err_drv_invalid_value)
1035             << HwasanAbiArg->getAsString(Args) << HwasanAbi;
1036     } else {
1037       HwasanAbi = "interceptor";
1038     }
1039     if (TC.getTriple().getArch() == llvm::Triple::x86_64)
1040       HwasanUseAliases = Args.hasFlag(
1041           options::OPT_fsanitize_hwaddress_experimental_aliasing,
1042           options::OPT_fno_sanitize_hwaddress_experimental_aliasing,
1043           HwasanUseAliases);
1044   }
1045 
1046   if (AllAddedKinds & SanitizerKind::SafeStack) {
1047     // SafeStack runtime is built into the system on Android and Fuchsia.
1048     SafeStackRuntime =
1049         !TC.getTriple().isAndroid() && !TC.getTriple().isOSFuchsia();
1050   }
1051 
1052   LinkRuntimes =
1053       Args.hasFlag(options::OPT_fsanitize_link_runtime,
1054                    options::OPT_fno_sanitize_link_runtime, LinkRuntimes);
1055 
1056   // Parse -link-cxx-sanitizer flag.
1057   LinkCXXRuntimes = Args.hasArg(options::OPT_fsanitize_link_cxx_runtime,
1058                                 options::OPT_fno_sanitize_link_cxx_runtime,
1059                                 LinkCXXRuntimes) ||
1060                     D.CCCIsCXX();
1061 
1062   NeedsMemProfRt = Args.hasFlag(options::OPT_fmemory_profile,
1063                                 options::OPT_fmemory_profile_EQ,
1064                                 options::OPT_fno_memory_profile, false);
1065 
1066   // Finally, initialize the set of available and recoverable sanitizers.
1067   Sanitizers.Mask |= Kinds;
1068   RecoverableSanitizers.Mask |= RecoverableKinds;
1069   TrapSanitizers.Mask |= TrappingKinds;
1070   assert(!(RecoverableKinds & TrappingKinds) &&
1071          "Overlap between recoverable and trapping sanitizers");
1072 }
1073 
1074 static std::string toString(const clang::SanitizerSet &Sanitizers) {
1075   std::string Res;
1076 #define SANITIZER(NAME, ID)                                                    \
1077   if (Sanitizers.has(SanitizerKind::ID)) {                                     \
1078     if (!Res.empty())                                                          \
1079       Res += ",";                                                              \
1080     Res += NAME;                                                               \
1081   }
1082 #include "clang/Basic/Sanitizers.def"
1083   return Res;
1084 }
1085 
1086 static void addSpecialCaseListOpt(const llvm::opt::ArgList &Args,
1087                                   llvm::opt::ArgStringList &CmdArgs,
1088                                   const char *SCLOptFlag,
1089                                   const std::vector<std::string> &SCLFiles) {
1090   for (const auto &SCLPath : SCLFiles) {
1091     SmallString<64> SCLOpt(SCLOptFlag);
1092     SCLOpt += SCLPath;
1093     CmdArgs.push_back(Args.MakeArgString(SCLOpt));
1094   }
1095 }
1096 
1097 static void addIncludeLinkerOption(const ToolChain &TC,
1098                                    const llvm::opt::ArgList &Args,
1099                                    llvm::opt::ArgStringList &CmdArgs,
1100                                    StringRef SymbolName) {
1101   SmallString<64> LinkerOptionFlag;
1102   LinkerOptionFlag = "--linker-option=/include:";
1103   if (TC.getTriple().getArch() == llvm::Triple::x86) {
1104     // Win32 mangles C function names with a '_' prefix.
1105     LinkerOptionFlag += '_';
1106   }
1107   LinkerOptionFlag += SymbolName;
1108   CmdArgs.push_back(Args.MakeArgString(LinkerOptionFlag));
1109 }
1110 
1111 static bool hasTargetFeatureMTE(const llvm::opt::ArgStringList &CmdArgs) {
1112   for (auto Start = CmdArgs.begin(), End = CmdArgs.end(); Start != End;
1113        ++Start) {
1114     auto It = std::find(Start, End, StringRef("+mte"));
1115     if (It == End)
1116       break;
1117     if (It > Start && *std::prev(It) == StringRef("-target-feature"))
1118       return true;
1119     Start = It;
1120   }
1121   return false;
1122 }
1123 
1124 void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
1125                             llvm::opt::ArgStringList &CmdArgs,
1126                             types::ID InputType) const {
1127   // NVPTX doesn't currently support sanitizers.  Bailing out here means
1128   // that e.g. -fsanitize=address applies only to host code, which is what we
1129   // want for now.
1130   if (TC.getTriple().isNVPTX())
1131     return;
1132   // AMDGPU sanitizer support is experimental and controlled by -fgpu-sanitize.
1133   bool GPUSanitize = false;
1134   if (TC.getTriple().isAMDGPU()) {
1135     if (!Args.hasFlag(options::OPT_fgpu_sanitize, options::OPT_fno_gpu_sanitize,
1136                       true))
1137       return;
1138     GPUSanitize = true;
1139   }
1140 
1141   // Translate available CoverageFeatures to corresponding clang-cc1 flags.
1142   // Do it even if Sanitizers.empty() since some forms of coverage don't require
1143   // sanitizers.
1144   std::pair<int, const char *> CoverageFlags[] = {
1145       std::make_pair(CoverageFunc, "-fsanitize-coverage-type=1"),
1146       std::make_pair(CoverageBB, "-fsanitize-coverage-type=2"),
1147       std::make_pair(CoverageEdge, "-fsanitize-coverage-type=3"),
1148       std::make_pair(CoverageIndirCall, "-fsanitize-coverage-indirect-calls"),
1149       std::make_pair(CoverageTraceBB, "-fsanitize-coverage-trace-bb"),
1150       std::make_pair(CoverageTraceCmp, "-fsanitize-coverage-trace-cmp"),
1151       std::make_pair(CoverageTraceDiv, "-fsanitize-coverage-trace-div"),
1152       std::make_pair(CoverageTraceGep, "-fsanitize-coverage-trace-gep"),
1153       std::make_pair(Coverage8bitCounters, "-fsanitize-coverage-8bit-counters"),
1154       std::make_pair(CoverageTracePC, "-fsanitize-coverage-trace-pc"),
1155       std::make_pair(CoverageTracePCGuard,
1156                      "-fsanitize-coverage-trace-pc-guard"),
1157       std::make_pair(CoverageInline8bitCounters,
1158                      "-fsanitize-coverage-inline-8bit-counters"),
1159       std::make_pair(CoverageInlineBoolFlag,
1160                      "-fsanitize-coverage-inline-bool-flag"),
1161       std::make_pair(CoveragePCTable, "-fsanitize-coverage-pc-table"),
1162       std::make_pair(CoverageNoPrune, "-fsanitize-coverage-no-prune"),
1163       std::make_pair(CoverageStackDepth, "-fsanitize-coverage-stack-depth"),
1164       std::make_pair(CoverageTraceLoads, "-fsanitize-coverage-trace-loads"),
1165       std::make_pair(CoverageTraceStores, "-fsanitize-coverage-trace-stores"),
1166       std::make_pair(CoverageControlFlow, "-fsanitize-coverage-control-flow")};
1167   for (auto F : CoverageFlags) {
1168     if (CoverageFeatures & F.first)
1169       CmdArgs.push_back(F.second);
1170   }
1171   addSpecialCaseListOpt(
1172       Args, CmdArgs, "-fsanitize-coverage-allowlist=", CoverageAllowlistFiles);
1173   addSpecialCaseListOpt(Args, CmdArgs, "-fsanitize-coverage-ignorelist=",
1174                         CoverageIgnorelistFiles);
1175 
1176   if (!GPUSanitize) {
1177     // Translate available BinaryMetadataFeatures to corresponding clang-cc1
1178     // flags. Does not depend on any other sanitizers. Unsupported on GPUs.
1179     const std::pair<int, std::string> BinaryMetadataFlags[] = {
1180         std::make_pair(BinaryMetadataCovered, "covered"),
1181         std::make_pair(BinaryMetadataAtomics, "atomics"),
1182         std::make_pair(BinaryMetadataUAR, "uar")};
1183     for (const auto &F : BinaryMetadataFlags) {
1184       if (BinaryMetadataFeatures & F.first)
1185         CmdArgs.push_back(
1186             Args.MakeArgString("-fexperimental-sanitize-metadata=" + F.second));
1187     }
1188     addSpecialCaseListOpt(Args, CmdArgs,
1189                           "-fexperimental-sanitize-metadata-ignorelist=",
1190                           BinaryMetadataIgnorelistFiles);
1191   }
1192 
1193   if (TC.getTriple().isOSWindows() && needsUbsanRt()) {
1194     // Instruct the code generator to embed linker directives in the object file
1195     // that cause the required runtime libraries to be linked.
1196     CmdArgs.push_back(
1197         Args.MakeArgString("--dependent-lib=" +
1198                            TC.getCompilerRTBasename(Args, "ubsan_standalone")));
1199     if (types::isCXX(InputType))
1200       CmdArgs.push_back(Args.MakeArgString(
1201           "--dependent-lib=" +
1202           TC.getCompilerRTBasename(Args, "ubsan_standalone_cxx")));
1203   }
1204   if (TC.getTriple().isOSWindows() && needsStatsRt()) {
1205     CmdArgs.push_back(Args.MakeArgString(
1206         "--dependent-lib=" + TC.getCompilerRTBasename(Args, "stats_client")));
1207 
1208     // The main executable must export the stats runtime.
1209     // FIXME: Only exporting from the main executable (e.g. based on whether the
1210     // translation unit defines main()) would save a little space, but having
1211     // multiple copies of the runtime shouldn't hurt.
1212     CmdArgs.push_back(Args.MakeArgString(
1213         "--dependent-lib=" + TC.getCompilerRTBasename(Args, "stats")));
1214     addIncludeLinkerOption(TC, Args, CmdArgs, "__sanitizer_stats_register");
1215   }
1216 
1217   if (Sanitizers.empty())
1218     return;
1219   CmdArgs.push_back(Args.MakeArgString("-fsanitize=" + toString(Sanitizers)));
1220 
1221   if (!RecoverableSanitizers.empty())
1222     CmdArgs.push_back(Args.MakeArgString("-fsanitize-recover=" +
1223                                          toString(RecoverableSanitizers)));
1224 
1225   if (!TrapSanitizers.empty())
1226     CmdArgs.push_back(
1227         Args.MakeArgString("-fsanitize-trap=" + toString(TrapSanitizers)));
1228 
1229   addSpecialCaseListOpt(Args, CmdArgs,
1230                         "-fsanitize-ignorelist=", UserIgnorelistFiles);
1231   addSpecialCaseListOpt(Args, CmdArgs,
1232                         "-fsanitize-system-ignorelist=", SystemIgnorelistFiles);
1233 
1234   if (MsanTrackOrigins)
1235     CmdArgs.push_back(Args.MakeArgString("-fsanitize-memory-track-origins=" +
1236                                          Twine(MsanTrackOrigins)));
1237 
1238   if (MsanUseAfterDtor)
1239     CmdArgs.push_back("-fsanitize-memory-use-after-dtor");
1240 
1241   if (!MsanParamRetval)
1242     CmdArgs.push_back("-fno-sanitize-memory-param-retval");
1243 
1244   // FIXME: Pass these parameters as function attributes, not as -llvm flags.
1245   if (!TsanMemoryAccess) {
1246     CmdArgs.push_back("-mllvm");
1247     CmdArgs.push_back("-tsan-instrument-memory-accesses=0");
1248     CmdArgs.push_back("-mllvm");
1249     CmdArgs.push_back("-tsan-instrument-memintrinsics=0");
1250   }
1251   if (!TsanFuncEntryExit) {
1252     CmdArgs.push_back("-mllvm");
1253     CmdArgs.push_back("-tsan-instrument-func-entry-exit=0");
1254   }
1255   if (!TsanAtomics) {
1256     CmdArgs.push_back("-mllvm");
1257     CmdArgs.push_back("-tsan-instrument-atomics=0");
1258   }
1259 
1260   if (HwasanUseAliases) {
1261     CmdArgs.push_back("-mllvm");
1262     CmdArgs.push_back("-hwasan-experimental-use-page-aliases=1");
1263   }
1264 
1265   if (CfiCrossDso)
1266     CmdArgs.push_back("-fsanitize-cfi-cross-dso");
1267 
1268   if (CfiICallGeneralizePointers)
1269     CmdArgs.push_back("-fsanitize-cfi-icall-generalize-pointers");
1270 
1271   if (CfiICallNormalizeIntegers)
1272     CmdArgs.push_back("-fsanitize-cfi-icall-experimental-normalize-integers");
1273 
1274   if (CfiCanonicalJumpTables)
1275     CmdArgs.push_back("-fsanitize-cfi-canonical-jump-tables");
1276 
1277   if (Stats)
1278     CmdArgs.push_back("-fsanitize-stats");
1279 
1280   if (MinimalRuntime)
1281     CmdArgs.push_back("-fsanitize-minimal-runtime");
1282 
1283   if (AsanFieldPadding)
1284     CmdArgs.push_back(Args.MakeArgString("-fsanitize-address-field-padding=" +
1285                                          Twine(AsanFieldPadding)));
1286 
1287   if (AsanUseAfterScope)
1288     CmdArgs.push_back("-fsanitize-address-use-after-scope");
1289 
1290   if (AsanPoisonCustomArrayCookie)
1291     CmdArgs.push_back("-fsanitize-address-poison-custom-array-cookie");
1292 
1293   if (AsanGlobalsDeadStripping)
1294     CmdArgs.push_back("-fsanitize-address-globals-dead-stripping");
1295 
1296   if (!AsanUseOdrIndicator)
1297     CmdArgs.push_back("-fno-sanitize-address-use-odr-indicator");
1298 
1299   if (AsanInvalidPointerCmp) {
1300     CmdArgs.push_back("-mllvm");
1301     CmdArgs.push_back("-asan-detect-invalid-pointer-cmp");
1302   }
1303 
1304   if (AsanInvalidPointerSub) {
1305     CmdArgs.push_back("-mllvm");
1306     CmdArgs.push_back("-asan-detect-invalid-pointer-sub");
1307   }
1308 
1309   if (AsanOutlineInstrumentation) {
1310     CmdArgs.push_back("-mllvm");
1311     CmdArgs.push_back("-asan-instrumentation-with-call-threshold=0");
1312   }
1313 
1314   // When emitting Stable ABI instrumentation, force outlining calls and avoid
1315   // inlining shadow memory poisoning. While this is a big performance burden
1316   // for now it allows full abstraction from implementation details.
1317   if (StableABI) {
1318     CmdArgs.push_back("-mllvm");
1319     CmdArgs.push_back("-asan-instrumentation-with-call-threshold=0");
1320     CmdArgs.push_back("-mllvm");
1321     CmdArgs.push_back("-asan-max-inline-poisoning-size=0");
1322   }
1323 
1324   // Only pass the option to the frontend if the user requested,
1325   // otherwise the frontend will just use the codegen default.
1326   if (AsanDtorKind != llvm::AsanDtorKind::Invalid) {
1327     CmdArgs.push_back(Args.MakeArgString("-fsanitize-address-destructor=" +
1328                                          AsanDtorKindToString(AsanDtorKind)));
1329   }
1330 
1331   if (AsanUseAfterReturn != llvm::AsanDetectStackUseAfterReturnMode::Invalid) {
1332     CmdArgs.push_back(Args.MakeArgString(
1333         "-fsanitize-address-use-after-return=" +
1334         AsanDetectStackUseAfterReturnModeToString(AsanUseAfterReturn)));
1335   }
1336 
1337   if (!HwasanAbi.empty()) {
1338     CmdArgs.push_back("-default-function-attr");
1339     CmdArgs.push_back(Args.MakeArgString("hwasan-abi=" + HwasanAbi));
1340   }
1341 
1342   if (Sanitizers.has(SanitizerKind::HWAddress) && !HwasanUseAliases) {
1343     CmdArgs.push_back("-target-feature");
1344     CmdArgs.push_back("+tagged-globals");
1345   }
1346 
1347   // MSan: Workaround for PR16386.
1348   // ASan: This is mainly to help LSan with cases such as
1349   // https://github.com/google/sanitizers/issues/373
1350   // We can't make this conditional on -fsanitize=leak, as that flag shouldn't
1351   // affect compilation.
1352   if (Sanitizers.has(SanitizerKind::Memory) ||
1353       Sanitizers.has(SanitizerKind::Address))
1354     CmdArgs.push_back("-fno-assume-sane-operator-new");
1355 
1356   // libFuzzer wants to intercept calls to certain library functions, so the
1357   // following -fno-builtin-* flags force the compiler to emit interposable
1358   // libcalls to these functions. Other sanitizers effectively do the same thing
1359   // by marking all library call sites with NoBuiltin attribute in their LLVM
1360   // pass. (see llvm::maybeMarkSanitizerLibraryCallNoBuiltin)
1361   if (Sanitizers.has(SanitizerKind::FuzzerNoLink)) {
1362     CmdArgs.push_back("-fno-builtin-bcmp");
1363     CmdArgs.push_back("-fno-builtin-memcmp");
1364     CmdArgs.push_back("-fno-builtin-strncmp");
1365     CmdArgs.push_back("-fno-builtin-strcmp");
1366     CmdArgs.push_back("-fno-builtin-strncasecmp");
1367     CmdArgs.push_back("-fno-builtin-strcasecmp");
1368     CmdArgs.push_back("-fno-builtin-strstr");
1369     CmdArgs.push_back("-fno-builtin-strcasestr");
1370     CmdArgs.push_back("-fno-builtin-memmem");
1371   }
1372 
1373   // Require -fvisibility= flag on non-Windows when compiling if vptr CFI is
1374   // enabled.
1375   if (Sanitizers.hasOneOf(CFIClasses) && !TC.getTriple().isOSWindows() &&
1376       !Args.hasArg(options::OPT_fvisibility_EQ)) {
1377     TC.getDriver().Diag(clang::diag::err_drv_argument_only_allowed_with)
1378         << lastArgumentForMask(TC.getDriver(), Args,
1379                                Sanitizers.Mask & CFIClasses)
1380         << "-fvisibility=";
1381   }
1382 
1383   if (Sanitizers.has(SanitizerKind::MemtagStack) &&
1384       !hasTargetFeatureMTE(CmdArgs))
1385     TC.getDriver().Diag(diag::err_stack_tagging_requires_hardware_feature);
1386 }
1387 
1388 SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A,
1389                              bool DiagnoseErrors) {
1390   assert((A->getOption().matches(options::OPT_fsanitize_EQ) ||
1391           A->getOption().matches(options::OPT_fno_sanitize_EQ) ||
1392           A->getOption().matches(options::OPT_fsanitize_recover_EQ) ||
1393           A->getOption().matches(options::OPT_fno_sanitize_recover_EQ) ||
1394           A->getOption().matches(options::OPT_fsanitize_trap_EQ) ||
1395           A->getOption().matches(options::OPT_fno_sanitize_trap_EQ)) &&
1396          "Invalid argument in parseArgValues!");
1397   SanitizerMask Kinds;
1398   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
1399     const char *Value = A->getValue(i);
1400     SanitizerMask Kind;
1401     // Special case: don't accept -fsanitize=all.
1402     if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
1403         0 == strcmp("all", Value))
1404       Kind = SanitizerMask();
1405     else
1406       Kind = parseSanitizerValue(Value, /*AllowGroups=*/true);
1407 
1408     if (Kind)
1409       Kinds |= Kind;
1410     else if (DiagnoseErrors)
1411       D.Diag(clang::diag::err_drv_unsupported_option_argument)
1412           << A->getSpelling() << Value;
1413   }
1414   return Kinds;
1415 }
1416 
1417 int parseCoverageFeatures(const Driver &D, const llvm::opt::Arg *A,
1418                           bool DiagnoseErrors) {
1419   assert(A->getOption().matches(options::OPT_fsanitize_coverage) ||
1420          A->getOption().matches(options::OPT_fno_sanitize_coverage));
1421   int Features = 0;
1422   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
1423     const char *Value = A->getValue(i);
1424     int F = llvm::StringSwitch<int>(Value)
1425                 .Case("func", CoverageFunc)
1426                 .Case("bb", CoverageBB)
1427                 .Case("edge", CoverageEdge)
1428                 .Case("indirect-calls", CoverageIndirCall)
1429                 .Case("trace-bb", CoverageTraceBB)
1430                 .Case("trace-cmp", CoverageTraceCmp)
1431                 .Case("trace-div", CoverageTraceDiv)
1432                 .Case("trace-gep", CoverageTraceGep)
1433                 .Case("8bit-counters", Coverage8bitCounters)
1434                 .Case("trace-pc", CoverageTracePC)
1435                 .Case("trace-pc-guard", CoverageTracePCGuard)
1436                 .Case("no-prune", CoverageNoPrune)
1437                 .Case("inline-8bit-counters", CoverageInline8bitCounters)
1438                 .Case("inline-bool-flag", CoverageInlineBoolFlag)
1439                 .Case("pc-table", CoveragePCTable)
1440                 .Case("stack-depth", CoverageStackDepth)
1441                 .Case("trace-loads", CoverageTraceLoads)
1442                 .Case("trace-stores", CoverageTraceStores)
1443                 .Case("control-flow", CoverageControlFlow)
1444                 .Default(0);
1445     if (F == 0 && DiagnoseErrors)
1446       D.Diag(clang::diag::err_drv_unsupported_option_argument)
1447           << A->getSpelling() << Value;
1448     Features |= F;
1449   }
1450   return Features;
1451 }
1452 
1453 int parseBinaryMetadataFeatures(const Driver &D, const llvm::opt::Arg *A,
1454                                 bool DiagnoseErrors) {
1455   assert(
1456       A->getOption().matches(options::OPT_fexperimental_sanitize_metadata_EQ) ||
1457       A->getOption().matches(
1458           options::OPT_fno_experimental_sanitize_metadata_EQ));
1459   int Features = 0;
1460   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
1461     const char *Value = A->getValue(i);
1462     int F = llvm::StringSwitch<int>(Value)
1463                 .Case("covered", BinaryMetadataCovered)
1464                 .Case("atomics", BinaryMetadataAtomics)
1465                 .Case("uar", BinaryMetadataUAR)
1466                 .Case("all", ~0)
1467                 .Default(0);
1468     if (F == 0 && DiagnoseErrors)
1469       D.Diag(clang::diag::err_drv_unsupported_option_argument)
1470           << A->getSpelling() << Value;
1471     Features |= F;
1472   }
1473   return Features;
1474 }
1475 
1476 std::string lastArgumentForMask(const Driver &D, const llvm::opt::ArgList &Args,
1477                                 SanitizerMask Mask) {
1478   for (llvm::opt::ArgList::const_reverse_iterator I = Args.rbegin(),
1479                                                   E = Args.rend();
1480        I != E; ++I) {
1481     const auto *Arg = *I;
1482     if (Arg->getOption().matches(options::OPT_fsanitize_EQ)) {
1483       SanitizerMask AddKinds =
1484           expandSanitizerGroups(parseArgValues(D, Arg, false));
1485       if (AddKinds & Mask)
1486         return describeSanitizeArg(Arg, Mask);
1487     } else if (Arg->getOption().matches(options::OPT_fno_sanitize_EQ)) {
1488       SanitizerMask RemoveKinds =
1489           expandSanitizerGroups(parseArgValues(D, Arg, false));
1490       Mask &= ~RemoveKinds;
1491     }
1492   }
1493   llvm_unreachable("arg list didn't provide expected value");
1494 }
1495 
1496 std::string describeSanitizeArg(const llvm::opt::Arg *A, SanitizerMask Mask) {
1497   assert(A->getOption().matches(options::OPT_fsanitize_EQ) &&
1498          "Invalid argument in describeSanitizerArg!");
1499 
1500   std::string Sanitizers;
1501   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
1502     if (expandSanitizerGroups(
1503             parseSanitizerValue(A->getValue(i), /*AllowGroups=*/true)) &
1504         Mask) {
1505       if (!Sanitizers.empty())
1506         Sanitizers += ",";
1507       Sanitizers += A->getValue(i);
1508     }
1509   }
1510 
1511   assert(!Sanitizers.empty() && "arg didn't provide expected value");
1512   return "-fsanitize=" + Sanitizers;
1513 }
1514