[esan] EfficiencySanitizer driver flags

[bruening]

Summary

Adds a framework to enable the instrumentation pass for the new
EfficiencySanitizer ("esan") family of tools. Adds a flag for esan's
cache fragmentation tool via -fsanitize=efficiency-cache-frag.

[filcab]

You probably want to add to IncompatibleGroups in SanitizerArgs.cpp.
This patch is missing test cases.

[bruening]

In D19169#406543, @filcab wrote:

You probably want to add to IncompatibleGroups in SanitizerArgs.cpp.
This patch is missing test cases.

Done.

[bruening]

Add test cases

[filcab]

LGTM

lib/Lex/PPMacroExpansion.cpp

1104

I wonder if we'll want a finer-grained feature, but for now this is good. We'll change/add if we need.

include/clang/Basic/Sanitizers.def

 
 SANITIZER_GROUP("integer", Integer,
                 SignedIntegerOverflow | UnsignedIntegerOverflow | Shift |
                 IntegerDivideByZero)
 
 SANITIZER("local-bounds", LocalBounds)
 SANITIZER_GROUP("bounds", Bounds, ArrayBounds | LocalBounds)
 
+// EfficiencySanitizer
+SANITIZER("efficiency-cache-frag", EfficiencyCacheFrag)
+// Meta-group only used internally.
+SANITIZER_GROUP("efficiency-all", Efficiency, EfficiencyCacheFrag)
+
 // Magic group, containing all sanitizers. For example, "-fno-sanitize=all"
 // can be used to disable all the sanitizers.
 SANITIZER_GROUP("all", All, ~0ULL)
 
 #undef SANITIZER
 #undef SANITIZER_GROUP

include/clang/Driver/SanitizerArgs.h

public:
   bool needsUbsanRt() const;
   bool needsDfsanRt() const { return Sanitizers.has(SanitizerKind::DataFlow); }
   bool needsSafeStackRt() const {
     return Sanitizers.has(SanitizerKind::SafeStack);
   }
   bool needsCfiRt() const;
   bool needsCfiDiagRt() const;
   bool needsStatsRt() const { return Stats; }
+  bool needsEsanRt() const {
+    return Sanitizers.hasOneOf(SanitizerKind::Efficiency);
+  }
 
   bool requiresPIE() const;
   bool needsUnwindTables() const;
   bool linkCXXRuntimes() const { return LinkCXXRuntimes; }
   void addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
                llvm::opt::ArgStringList &CmdArgs, types::ID InputType) const;
 };
 
 }  // namespace driver
 }  // namespace clang
 
 #endif

lib/CodeGen/BackendUtil.cpp

 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
                                      legacy::PassManagerBase &PM) {
   const PassManagerBuilderWrapper &BuilderWrapper =
       static_cast<const PassManagerBuilderWrapper&>(Builder);
   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
 }
 
+static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder,
+                                       legacy::PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
+  EfficiencySanitizerOptions Opts;
+  if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyCacheFrag))
+    Opts.ToolType = EfficiencySanitizerOptions::ESAN_CacheFrag;
+  PM.add(createEfficiencySanitizerPass(Opts));
+}
+
 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
                                          const CodeGenOptions &CodeGenOpts) {
   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
   if (!CodeGenOpts.SimplifyLibCalls)
     TLII->disableAllFunctions();
   else {
     // Disable individual libc/libm calls in TargetLibraryInfo.
     LibFunc::Func F;
void EmitAssemblyHelper::CreatePasses(ModuleSummaryIndex *ModuleSummary) {
 
   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addDataFlowSanitizerPass);
     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
                            addDataFlowSanitizerPass);
   }
 
+  if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addEfficiencySanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addEfficiencySanitizerPass);
+  }
+
   // Set up the per-function pass manager.
   legacy::FunctionPassManager *FPM = getPerFunctionPasses();
   if (CodeGenOpts.VerifyModule)
     FPM->add(createVerifierPass());
   PMBuilder.populateFunctionPassManager(*FPM);
 
   // Set up the per-module pass manager.
   if (!CodeGenOpts.RewriteMapFiles.empty())

lib/Driver/SanitizerArgs.cpp

SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 
   // Warn about incompatible groups of sanitizers.
   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
       std::make_pair(Address, Thread), std::make_pair(Address, Memory),
       std::make_pair(Thread, Memory), std::make_pair(Leak, Thread),
       std::make_pair(Leak, Memory), std::make_pair(KernelAddress, Address),
       std::make_pair(KernelAddress, Leak),
       std::make_pair(KernelAddress, Thread),
-      std::make_pair(KernelAddress, Memory)};
+      std::make_pair(KernelAddress, Memory),
+      std::make_pair(Efficiency, Address),
+      std::make_pair(Efficiency, Leak),
+      std::make_pair(Efficiency, Thread),
+      std::make_pair(Efficiency, Memory),
+      std::make_pair(Efficiency, KernelAddress)};
   for (auto G : IncompatibleGroups) {
     SanitizerMask Group = G.first;
     if (Kinds & Group) {
       if (SanitizerMask Incompatible = Kinds & G.second) {
         D.Diag(clang::diag::err_drv_argument_not_allowed_with)
             << lastArgumentForMask(D, Args, Group)
             << lastArgumentForMask(D, Args, Incompatible);
         Kinds &= ~Incompatible;
SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A,
   SanitizerMask Kinds = 0;
   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
     const char *Value = A->getValue(i);
     SanitizerMask Kind;
     // Special case: don't accept -fsanitize=all.
     if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
         0 == strcmp("all", Value))
       Kind = 0;
+    // Similarly, don't accept -fsanitize=efficiency-all.
+    else if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
+        0 == strcmp("efficiency-all", Value))
+      Kind = 0;
     else
       Kind = parseSanitizerValue(Value, /*AllowGroups=*/true);
 
     if (Kind)
       Kinds |= Kind;
     else if (DiagnoseErrors)
       D.Diag(clang::diag::err_drv_unsupported_option_argument)
           << A->getOption().getName() << Value;

lib/Driver/ToolChains.cpp

if (Sanitize.needsTsanRt())
     AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan");
   if (Sanitize.needsStatsRt()) {
     StringRef OS = isTargetMacOS() ? "osx" : "iossim";
     AddLinkRuntimeLib(Args, CmdArgs,
                       (Twine("libclang_rt.stats_client_") + OS + ".a").str(),
                       /*AlwaysLink=*/true);
     AddLinkSanitizerLibArgs(Args, CmdArgs, "stats");
   }
+  if (Sanitize.needsEsanRt())
+    AddLinkSanitizerLibArgs(Args, CmdArgs, "esan");
 
   // Otherwise link libSystem, then the dynamic runtime library, and finally any
   // target specific static runtime library.
   CmdArgs.push_back("-lSystem");
 
   // Select the dynamic runtime library and the target specific static library.
   if (isTargetWatchOSBased()) {
     // We currently always need a static runtime library for watchOS.
SanitizerMask Linux::getSupportedSanitizers() const {
   if (IsX86_64 || IsMIPS64 || IsAArch64)
     Res |= SanitizerKind::DataFlow;
   if (IsX86_64 || IsMIPS64 || IsAArch64)
     Res |= SanitizerKind::Leak;
   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsPowerPC64)
     Res |= SanitizerKind::Thread;
   if (IsX86_64 || IsMIPS64 || IsPowerPC64 || IsAArch64)
     Res |= SanitizerKind::Memory;
+  if (IsX86_64)
+    Res |= SanitizerKind::Efficiency;
   if (IsX86 || IsX86_64) {
     Res |= SanitizerKind::Function;
   }
   return Res;
 }
 
 void Linux::addProfileRTLibs(const llvm::opt::ArgList &Args,
                              llvm::opt::ArgStringList &CmdArgs) const {

lib/Driver/Tools.cpp

if (SanArgs.needsCfiDiagRt()) {
     StaticRuntimes.push_back("cfi_diag");
     if (SanArgs.linkCXXRuntimes())
       StaticRuntimes.push_back("ubsan_standalone_cxx");
   }
   if (SanArgs.needsStatsRt()) {
     NonWholeStaticRuntimes.push_back("stats");
     RequiredSymbols.push_back("__sanitizer_stats_register");
   }
+  if (SanArgs.needsEsanRt())
+    StaticRuntimes.push_back("esan");
 }
 
 // Should be called before we add system libraries (C++ ABI, libstdc++/libc++,
 // C runtime, etc). Returns true if sanitizer system deps need to be linked in.
 static bool addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
                                  ArgStringList &CmdArgs) {
   SmallVector<StringRef, 4> SharedRuntimes, StaticRuntimes,
       NonWholeStaticRuntimes, HelperStaticRuntimes, RequiredSymbols;

lib/Lex/PPMacroExpansion.cpp

return llvm::StringSwitch<bool>(Feature)
       .Case("c_thread_safety_attributes", true)
       .Case("cxx_exceptions", LangOpts.CXXExceptions)
       .Case("cxx_rtti", LangOpts.RTTI && LangOpts.RTTIData)
       .Case("enumerator_attributes", true)
       .Case("nullability", true)
       .Case("memory_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Memory))
       .Case("thread_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Thread))
       .Case("dataflow_sanitizer", LangOpts.Sanitize.has(SanitizerKind::DataFlow))
+      .Case("efficiency_sanitizer",
+            LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency))
       // Objective-C features
       .Case("objc_arr", LangOpts.ObjCAutoRefCount) // FIXME: REMOVE?
       .Case("objc_arc", LangOpts.ObjCAutoRefCount)
       .Case("objc_arc_weak", LangOpts.ObjCWeak)
       .Case("objc_default_synthesize_properties", LangOpts.ObjC2)
       .Case("objc_fixed_enum", LangOpts.ObjC2)
       .Case("objc_instancetype", LangOpts.ObjC2)
       .Case("objc_kindof", LangOpts.ObjC2)

test/Driver/esan.c

+// RUN: %clang     -target x86_64-unknown-linux -fsanitize=efficiency-cache-frag %s -S -emit-llvm -o - | FileCheck %s
+// RUN: %clang -O1 -target x86_64-unknown-linux -fsanitize=efficiency-cache-frag %s -S -emit-llvm -o - | FileCheck %s
+// RUN: %clang -O2 -target x86_64-unknown-linux -fsanitize=efficiency-cache-frag %s -S -emit-llvm -o - | FileCheck %s
+// RUN: %clang -O3 -target x86_64-unknown-linux -fsanitize=efficiency-cache-frag %s -S -emit-llvm -o - | FileCheck %s
+// RUN: %clang     -target x86_64-unknown-linux -fsanitize=efficiency-cache-frag  %s -S -emit-llvm -o - | FileCheck %s
+// Verify that -fsanitize=efficiency-cache-frag invokes esan instrumentation.
+
+int foo(int *a) { return *a; }
+// CHECK: __esan_init

test/Driver/fsanitize.c

 // CHECK-SANKA-SANM: '-fsanitize=kernel-address' not allowed with '-fsanitize=memory'
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=kernel-address,address -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANKA-SANA
 // CHECK-SANKA-SANA: '-fsanitize=kernel-address' not allowed with '-fsanitize=address'
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=kernel-address,leak -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANKA-SANL
 // CHECK-SANKA-SANL: '-fsanitize=kernel-address' not allowed with '-fsanitize=leak'
 
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag,address -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANE-SANA
+// CHECK-SANE-SANA: '-fsanitize=efficiency-cache-frag' not allowed with '-fsanitize=address'
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag,leak -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANE-SANL
+// CHECK-SANE-SANL: '-fsanitize=efficiency-cache-frag' not allowed with '-fsanitize=leak'
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag,thread -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANE-SANT
+// CHECK-SANE-SANT: '-fsanitize=efficiency-cache-frag' not allowed with '-fsanitize=thread'
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag,memory -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANE-SANM
+// CHECK-SANE-SANM: '-fsanitize=efficiency-cache-frag' not allowed with '-fsanitize=memory'
+
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag,kernel-address -pie -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANE-SANKA
+// CHECK-SANE-SANKA: '-fsanitize=efficiency-cache-frag' not allowed with '-fsanitize=kernel-address'
+
 // RUN: %clang -target x86_64-linux-gnu -fsanitize-memory-track-origins -pie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ONLY-TRACK-ORIGINS
 // CHECK-ONLY-TRACK-ORIGINS: warning: argument unused during compilation: '-fsanitize-memory-track-origins'
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=memory -fno-sanitize=memory -fsanitize-memory-track-origins -pie %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TRACK-ORIGINS-DISABLED-MSAN
 // CHECK-TRACK-ORIGINS-DISABLED-MSAN-NOT: warning: argument unused
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-EXTRA-TRACK-ORIGINS
 // CHECK-NO-EXTRA-TRACK-ORIGINS-NOT: "-fsanitize-memory-track-origins"

 // CHECK-VPTR-DARWIN-NEW: -fsanitize=alignment,vptr
 
 // RUN: %clang -target armv7-apple-ios7 -miphoneos-version-min=7.0 -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-IOS
 // CHECK-ASAN-IOS: -fsanitize=address
 
 // RUN: %clang -target i386-pc-openbsd -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-OPENBSD
 // CHECK-ASAN-OPENBSD: unsupported option '-fsanitize=address' for target 'i386-pc-openbsd'
 
+// RUN: %clang -target i686-linux-gnu -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-X86
+// CHECK-ESAN-X86: error: unsupported option '-fsanitize=efficiency-cache-frag' for target 'i686--linux-gnu'
+
+// RUN: %clang -target x86_64-apple-darwin10 -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-DARWIN
+// CHECK-ESAN-DARWIN: unsupported option '-fsanitize=efficiency-cache-frag' for target 'x86_64-apple-darwin10'
+
+// RUN: %clang -target i386-apple-darwin -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-I386-DARWIN
+// CHECK-ESAN-I386-DARWIN: unsupported option '-fsanitize=efficiency-cache-frag' for target 'i386-apple-darwin'
+
+// RUN: %clang -target arm-apple-ios -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-ARM-IOS
+// CHECK-ESAN-ARM-IOS: unsupported option '-fsanitize=efficiency-cache-frag' for target 'arm-apple-ios'
+
+// RUN: %clang -target i386-apple-iossimulator -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-I386-IOSSIMULATOR
+// CHECK-ESAN-I386-IOSSIMULATOR: unsupported option '-fsanitize=efficiency-cache-frag' for target 'i386-apple-iossimulator'
+
+// RUN: %clang -target i386-apple-tvossimulator -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-I386-TVOSSIMULATOR
+// CHECK-ESAN-I386-TVOSSIMULATOR: unsupported option '-fsanitize=efficiency-cache-frag' for target 'i386-apple-tvossimulator'
+
+
+
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang -target x86_64-apple-darwin10 -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi-derived-cast -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-DCAST
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=cfi-unrelated-cast -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-UCAST
 // RUN: %clang -target x86_64-linux-gnu -flto -fsanitize=cfi-nvcall -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-NVCALL
 // RUN: %clang -target x86_64-linux-gnu -flto -fsanitize=cfi-vcall -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI-VCALL
 // CHECK-CFI: -emit-llvm-bc{{.*}}-fsanitize=cfi-derived-cast,cfi-icall,cfi-unrelated-cast,cfi-nvcall,cfi-vcall
 // CHECK-CFI-DCAST: -emit-llvm-bc{{.*}}-fsanitize=cfi-derived-cast

 // RUN: %clang -target x86_64-scei-ps4 -fsanitize=dataflow %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-DFSAN-PS4
 // CHECK-DFSAN-PS4: unsupported option '-fsanitize=dataflow' for target 'x86_64-scei-ps4'
 // RUN: %clang -target x86_64-scei-ps4 -fsanitize=leak %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-LSAN-PS4
 // CHECK-LSAN-PS4: unsupported option '-fsanitize=leak' for target 'x86_64-scei-ps4'
 // RUN: %clang -target x86_64-scei-ps4 -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-MSAN-PS4
 // CHECK-MSAN-PS4: unsupported option '-fsanitize=memory' for target 'x86_64-scei-ps4'
 // RUN: %clang -target x86_64-scei-ps4 -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-PS4
 // CHECK-TSAN-PS4: unsupported option '-fsanitize=thread' for target 'x86_64-scei-ps4'
+// RUN: %clang -target x86_64-scei-ps4 -fsanitize=efficiency-cache-frag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ESAN-PS4
+// CHECK-ESAN-PS4: unsupported option '-fsanitize=efficiency-cache-frag' for target 'x86_64-scei-ps4'
 // RUN: %clang -target x86_64-scei-ps4 -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-PS4
 // Make sure there are no *.{o,bc} or -l passed before the ASan library.
 // CHECK-ASAN-PS4-NOT: {{(\.(o|bc)"? |-l).*-lSceDbgAddressSanitizer_stub_weak}}
 // CHECK-ASAN-PS4: -lSceDbgAddressSanitizer_stub_weak

test/Driver/sanitize_unwind_tables.c

 // Sanitizers need to unwind stack at any code location.
 // Test that unwind tables are enabled in supported configurations.
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address %s -### 2>&1 |  FileCheck %s
 // RUN: %clang -target i686-linux-gnu -fsanitize=address %s -### 2>&1 |  FileCheck %s
 // RUN: %clang -target arm-linux-androideabi -fsanitize=address %s -### 2>&1 |  FileCheck %s
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=memory %s -### 2>&1 |  FileCheck %s
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=thread %s -### 2>&1 |  FileCheck %s
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=dataflow %s -### 2>&1 |  FileCheck %s
+// RUN: %clang -target x86_64-linux-gnu -fsanitize=efficiency-cache-frag %s -### 2>&1 |  FileCheck %s
 
 // CHECK: -munwind-tables

test/Driver/sanitizer-ld.c

 // CHECK-ASAN-PS4: -lSceDbgAddressSanitizer_stub_weak
 
 // RUN: %clang -fsanitize=address,undefined %s -### -o %t.o 2>&1 \
 // RUN:     -target x86_64-scei-ps4 \
 // RUN:     -shared \
 // RUN:   | FileCheck --check-prefix=CHECK-AUBSAN-PS4 %s
 // CHECK-AUBSAN-PS4: "{{.*}}ld{{(.gold)?(.exe)?}}"
 // CHECK-AUBSAN-PS4: -lSceDbgAddressSanitizer_stub_weak
+
+// RUN: %clang -fsanitize=efficiency-cache-frag %s -### -o %t.o 2>&1 \
+// RUN:     -target x86_64-unknown-linux \
+// RUN:   | FileCheck --check-prefix=CHECK-ESAN-LINUX %s
+//
+// CHECK-ESAN-LINUX: "{{(.*[^-.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
+// CHECK-ESAN-LINUX: libclang_rt.esan-x86_64.a

test/Lexer/has_feature_efficiency_sanitizer.cpp

+// RUN: %clang_cc1 -E -fsanitize=efficiency-cache-frag %s -o - | FileCheck --check-prefix=CHECK-ESAN %s
+// RUN: %clang_cc1 -E  %s -o - | FileCheck --check-prefix=CHECK-NO-ESAN %s
+
+#if __has_feature(efficiency_sanitizer)
+int EfficiencySanitizerEnabled();
+#else
+int EfficiencySanitizerDisabled();
+#endif
+
+// CHECK-ESAN: EfficiencySanitizerEnabled
+// CHECK-NO-ESAN: EfficiencySanitizerDisabled