Revert "[ubsan] Connect -fsanitize-skip-hot-cutoff to LowerAllowCheckPass<cutoffs>" (#125032)

Reverts #124857 due to buildbot breakage
(https://lab.llvm.org/buildbot/#/builders/46/builds/11310)

Author: thurstond

clang/include/clang/Basic/Sanitizers.h

@@ -162,10 +162,6 @@ class SanitizerMaskCutoffs {
 
   void set(SanitizerMask K, double V);
   void clear(SanitizerMask K = SanitizerKind::All);
-
-  // Returns nullopt if all the values are zero.
-  // Otherwise, return value contains a vector of all the scaled values.
-  std::optional<std::vector<unsigned>> getAllScaled(unsigned ScalingFactor) const;
 };
 
 struct SanitizerSet {

clang/lib/Basic/Sanitizers.cpp

@@ -18,7 +18,6 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
-#include <cmath>
 #include <optional>
 
 using namespace clang;
@@ -44,27 +43,6 @@ std::optional<double> SanitizerMaskCutoffs::operator[](unsigned Kind) const {
 
 void SanitizerMaskCutoffs::clear(SanitizerMask K) { set(K, 0); }
 
-std::optional<std::vector<unsigned>>
-SanitizerMaskCutoffs::getAllScaled(unsigned ScalingFactor) const {
-  std::vector<unsigned> ScaledCutoffs;
-
-  bool AnyCutoff = false;
-  for (unsigned int i = 0; i < SanitizerKind::SO_Count; ++i) {
-    auto C = (*this)[i];
-    if (C.has_value()) {
-      ScaledCutoffs.push_back(lround(std::clamp(*C, 0.0, 1.0) * ScalingFactor));
-      AnyCutoff = true;
-    } else {
-      ScaledCutoffs.push_back(0);
-    }
-  }
-
-  if (AnyCutoff)
-    return ScaledCutoffs;
-
-  return std::nullopt;
-}
-
 // Once LLVM switches to C++17, the constexpr variables can be inline and we
 // won't need this.
 #define SANITIZER(NAME, ID) constexpr SanitizerMask SanitizerKind::ID;

clang/lib/CodeGen/BackendUtil.cpp

@@ -795,20 +795,12 @@ static void addSanitizers(const Triple &TargetTriple,
     PB.registerOptimizerLastEPCallback(SanitizersCallback);
   }
 
-  // SanitizeSkipHotCutoffs: doubles with range [0, 1]
-  // Opts.cutoffs: unsigned ints with range [0, 1000000]
-  auto ScaledCutoffs = CodeGenOpts.SanitizeSkipHotCutoffs.getAllScaled(1000000);
-
-  // TODO: remove IsRequested()
-  if (LowerAllowCheckPass::IsRequested() || ScaledCutoffs.has_value()) {
+  if (LowerAllowCheckPass::IsRequested()) {
     // We want to call it after inline, which is about OptimizerEarlyEPCallback.
     PB.registerOptimizerEarlyEPCallback([&](ModulePassManager &MPM,
                                             OptimizationLevel Level,
                                             ThinOrFullLTOPhase Phase) {
       LowerAllowCheckPass::Options Opts;
-      // TODO: after removing IsRequested(), make this unconditional
-      if (ScaledCutoffs.has_value())
-        Opts.cutoffs = ScaledCutoffs.value();
       MPM.addPass(createModuleToFunctionPassAdaptor(LowerAllowCheckPass(Opts)));
     });
   }

clang/lib/CodeGen/CGExpr.cpp

@@ -3614,33 +3614,29 @@ void CodeGenFunction::EmitCheck(
   llvm::Value *RecoverableCond = nullptr;
   llvm::Value *TrapCond = nullptr;
   bool NoMerge = false;
-  // Expand checks into:
-  //   (Check1 || !allow_ubsan_check) && (Check2 || !allow_ubsan_check) ...
-  // We need separate allow_ubsan_check intrinsics because they have separately
-  // specified cutoffs.
-  // This expression looks expensive but will be simplified after
-  // LowerAllowCheckPass.
   for (auto &[Check, Ord] : Checked) {
-    llvm::Value *GuardedCheck = Check;
-    if (ClSanitizeGuardChecks ||
-        (CGM.getCodeGenOpts().SanitizeSkipHotCutoffs[Ord] > 0)) {
-      llvm::Value *Allow = Builder.CreateCall(
-          CGM.getIntrinsic(llvm::Intrinsic::allow_ubsan_check),
-          llvm::ConstantInt::get(CGM.Int8Ty, Ord));
-      GuardedCheck = Builder.CreateOr(Check, Builder.CreateNot(Allow));
-    }
-
     // -fsanitize-trap= overrides -fsanitize-recover=.
     llvm::Value *&Cond = CGM.getCodeGenOpts().SanitizeTrap.has(Ord) ? TrapCond
                          : CGM.getCodeGenOpts().SanitizeRecover.has(Ord)
                              ? RecoverableCond
                              : FatalCond;
-    Cond = Cond ? Builder.CreateAnd(Cond, GuardedCheck) : GuardedCheck;
+    Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
 
     if (!CGM.getCodeGenOpts().SanitizeMergeHandlers.has(Ord))
       NoMerge = true;
   }
 
+  if (ClSanitizeGuardChecks) {
+    llvm::Value *Allow =
+        Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::allow_ubsan_check),
+                           llvm::ConstantInt::get(CGM.Int8Ty, CheckHandler));
+
+    for (llvm::Value **Cond : {&FatalCond, &RecoverableCond, &TrapCond}) {
+      if (*Cond)
+        *Cond = Builder.CreateOr(*Cond, Builder.CreateNot(Allow));
+    }
+  }
+
   if (TrapCond)
     EmitTrapCheck(TrapCond, CheckHandler, NoMerge);
   if (!FatalCond && !RecoverableCond)

clang/test/CodeGen/allow-ubsan-check-inline.c

@@ -1,8 +1,3 @@
-// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s -fsanitize=signed-integer-overflow -fsanitize-skip-hot-cutoff=signed-integer-overflow=0.000001 -O3 -mllvm -lower-allow-check-random-rate=1 -Rpass=lower-allow-check -Rpass-missed=lower-allow-check -fno-inline 2>&1 | FileCheck %s --check-prefixes=NOINL --implicit-check-not="remark:"
-// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s -fsanitize=signed-integer-overflow -fsanitize-skip-hot-cutoff=signed-integer-overflow=0.000001 -O3 -mllvm -lower-allow-check-random-rate=1 -Rpass=lower-allow-check -Rpass-missed=lower-allow-check 2>&1 | FileCheck %s --check-prefixes=INLINE --implicit-check-not="remark:"
-//
-// -ubsan-guard-checks is deprecated and will be removed in the future;
-// use -fsanitize-skip-hot-cutoff, as shown above.
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s -fsanitize=signed-integer-overflow -mllvm -ubsan-guard-checks -O3 -mllvm -lower-allow-check-random-rate=1 -Rpass=lower-allow-check -Rpass-missed=lower-allow-check -fno-inline 2>&1 | FileCheck %s --check-prefixes=NOINL --implicit-check-not="remark:"
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -o - %s -fsanitize=signed-integer-overflow -mllvm -ubsan-guard-checks -O3 -mllvm -lower-allow-check-random-rate=1 -Rpass=lower-allow-check -Rpass-missed=lower-allow-check 2>&1 | FileCheck %s --check-prefixes=INLINE --implicit-check-not="remark:"