[UBSAN][HWASAN] Remove redundant flags (#87709)

Presense of `cutoff-hot` or `random-skip-rate`
should be enough to trigger optimization.

Author: vitalybuka

clang/lib/CodeGen/BackendUtil.cpp

@@ -100,9 +100,6 @@ using namespace llvm;
 namespace llvm {
 extern cl::opt<bool> PrintPipelinePasses;
 
-static cl::opt<bool> ClRemoveTraps("clang-remove-traps", cl::Optional,
-                                   cl::desc("Insert remove-traps pass."));
-
 // Experiment to move sanitizers earlier.
 static cl::opt<bool> ClSanitizeOnOptimizerEarlyEP(
     "sanitizer-early-opt-ep", cl::Optional,
@@ -750,7 +747,7 @@ static void addSanitizers(const Triple &TargetTriple,
     PB.registerOptimizerLastEPCallback(SanitizersCallback);
   }
 
-  if (ClRemoveTraps) {
+  if (RemoveTrapsPass::IsRequested()) {
     // We can optimize after inliner, and PGO profile matching. The hook below
     // is called at the end `buildFunctionSimplificationPipeline`, which called
     // from `buildInlinerPipeline`, which called after profile matching.

clang/test/CodeGen/remote-traps.c

@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -O1 -emit-llvm -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow %s -o - | FileCheck %s 
-// RUN: %clang_cc1 -O1 -emit-llvm -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow -mllvm -clang-remove-traps -mllvm -remove-traps-random-rate=1 %s -o - | FileCheck %s --implicit-check-not="call void @llvm.ubsantrap" --check-prefixes=REMOVE
+// RUN: %clang_cc1 -O1 -emit-llvm -fsanitize=signed-integer-overflow -fsanitize-trap=signed-integer-overflow -mllvm -remove-traps-random-rate=1 %s -o - | FileCheck %s --implicit-check-not="call void @llvm.ubsantrap" --check-prefixes=REMOVE
 
 int test(int x) {
   return x + 123;

llvm/include/llvm/Transforms/Instrumentation/RemoveTrapsPass.h

@@ -25,6 +25,8 @@ namespace llvm {
 class RemoveTrapsPass : public PassInfoMixin<RemoveTrapsPass> {
 public:
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+
+  static bool IsRequested();
 };
 
 } // namespace llvm

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

@@ -182,11 +182,6 @@ static cl::opt<bool> ClWithTls(
              "platforms that support this"),
     cl::Hidden, cl::init(true));
 
-static cl::opt<bool>
-    CSelectiveInstrumentation("hwasan-selective-instrumentation",
-                              cl::desc("Use selective instrumentation"),
-                              cl::Hidden, cl::init(false));
-
 static cl::opt<int> ClHotPercentileCutoff("hwasan-percentile-cutoff-hot",
                                           cl::desc("Hot percentile cuttoff."));
 
@@ -1503,6 +1498,8 @@ bool HWAddressSanitizer::selectiveInstrumentationShouldSkip(
     std::bernoulli_distribution D(ClRandomSkipRate);
     return (D(*Rng));
   }
+  if (!ClHotPercentileCutoff.getNumOccurrences())
+    return false;
   auto &MAMProxy = FAM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
   ProfileSummaryInfo *PSI =
       MAMProxy.getCachedResult<ProfileSummaryAnalysis>(*F.getParent());
@@ -1527,7 +1524,7 @@ void HWAddressSanitizer::sanitizeFunction(Function &F,
 
   NumTotalFuncs++;
 
-  if (CSelectiveInstrumentation && selectiveInstrumentationShouldSkip(F, FAM))
+  if (selectiveInstrumentationShouldSkip(F, FAM))
     return;
 
   NumInstrumentedFuncs++;

llvm/lib/Transforms/Instrumentation/RemoveTrapsPass.cpp

@@ -41,6 +41,7 @@ static bool removeUbsanTraps(Function &F, const BlockFrequencyInfo &BFI,
   auto ShouldRemove = [&](bool IsHot) {
     if (!RandomRate.getNumOccurrences())
       return IsHot;
+    assert(HotPercentileCutoff.getNumOccurrences());
     if (!Rng)
       Rng = F.getParent()->createRNG(F.getName());
     std::bernoulli_distribution D(RandomRate);
@@ -95,3 +96,8 @@ PreservedAnalyses RemoveTrapsPass::run(Function &F,
   return removeUbsanTraps(F, BFI, PSI) ? PreservedAnalyses::none()
                                        : PreservedAnalyses::all();
 }
+
+bool RemoveTrapsPass::IsRequested() {
+  return RandomRate.getNumOccurrences() ||
+         HotPercentileCutoff.getNumOccurrences();
+}

llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out-no-ps.ll

@@ -1,7 +1,5 @@
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S  \
-; RUN:   -hwasan-selective-instrumentation=0 | FileCheck %s --check-prefix=FULL
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S  \
-; RUN:   -hwasan-selective-instrumentation=1 | FileCheck %s --check-prefix=SELSAN
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S                                      | FileCheck %s --check-prefix=FULL
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-percentile-cutoff-hot=990000 | FileCheck %s --check-prefix=SELSAN
 
 ; FULL: @not_sanitized
 ; FULL-NEXT: %x = alloca i8, i64 4

llvm/test/Instrumentation/HWAddressSanitizer/pgo-opt-out.ll

@@ -1,11 +1,7 @@
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
-; RUN:    -hwasan-percentile-cutoff-hot=700000 | FileCheck %s --check-prefix=HOT70
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
-; RUN:    -hwasan-percentile-cutoff-hot=990000 | FileCheck %s --check-prefix=HOT99
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
-; RUN:    -hwasan-random-skip-rate=0.0 | FileCheck %s --check-prefix=RANDOM0
-; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-selective-instrumentation=1 \
-; RUN:    -hwasan-random-skip-rate=1.0 | FileCheck %s --check-prefix=RANDOM1
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-percentile-cutoff-hot=700000 | FileCheck %s --check-prefix=HOT70
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-percentile-cutoff-hot=990000 | FileCheck %s --check-prefix=HOT99
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-random-skip-rate=0.0 | FileCheck %s --check-prefix=RANDOM0
+; RUN: opt < %s -passes='require<profile-summary>,hwasan' -S -hwasan-random-skip-rate=1.0 | FileCheck %s --check-prefix=RANDOM1
 
 ; HOT70: @sanitized
 ; HOT70-NEXT: @__hwasan_tls