Revert D135411 "Add generic KCFI operand bundle lowering"

This reverts commit eb2a57e.

llvm/include/llvm/Transforms/Instrumentation/KCFI.h including
llvm/CodeGen is a layering violation. We should use an approach where
Instrumementation/ doesn't need to include CodeGen/.
Sorry for not spotting this in the review.

Author: MaskRay

clang/lib/CodeGen/BackendUtil.cpp

@@ -72,7 +72,6 @@
 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
-#include "llvm/Transforms/Instrumentation/KCFI.h"
 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
 #include "llvm/Transforms/Instrumentation/SanitizerBinaryMetadata.h"
@@ -645,31 +644,6 @@ static OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
   }
 }
 
-static void addKCFIPass(TargetMachine *TM, const Triple &TargetTriple,
-                        const LangOptions &LangOpts, PassBuilder &PB) {
-  // If the back-end supports KCFI operand bundle lowering, skip KCFIPass.
-  if (TargetTriple.getArch() == llvm::Triple::x86_64 ||
-      TargetTriple.isAArch64(64))
-    return;
-
-  // Ensure we lower KCFI operand bundles with -O0.
-  PB.registerOptimizerLastEPCallback(
-      [&, TM](ModulePassManager &MPM, OptimizationLevel Level) {
-        if (Level == OptimizationLevel::O0 &&
-            LangOpts.Sanitize.has(SanitizerKind::KCFI))
-          MPM.addPass(createModuleToFunctionPassAdaptor(KCFIPass(TM)));
-      });
-
-  // When optimizations are requested, run KCIFPass after InstCombine to
-  // avoid unnecessary checks.
-  PB.registerPeepholeEPCallback(
-      [&, TM](FunctionPassManager &FPM, OptimizationLevel Level) {
-        if (Level != OptimizationLevel::O0 &&
-            LangOpts.Sanitize.has(SanitizerKind::KCFI))
-          FPM.addPass(KCFIPass(TM));
-      });
-}
-
 static void addSanitizers(const Triple &TargetTriple,
                           const CodeGenOptions &CodeGenOpts,
                           const LangOptions &LangOpts, PassBuilder &PB) {
@@ -972,10 +946,8 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
 
     // Don't add sanitizers if we are here from ThinLTO PostLink. That already
     // done on PreLink stage.
-    if (!IsThinLTOPostLink) {
+    if (!IsThinLTOPostLink)
       addSanitizers(TargetTriple, CodeGenOpts, LangOpts, PB);
-      addKCFIPass(TM.get(), TargetTriple, LangOpts, PB);
-    }
 
     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
       PB.registerPipelineStartEPCallback(

clang/lib/Driver/ToolChain.cpp

@@ -1089,14 +1089,17 @@ SanitizerMask ToolChain::getSupportedSanitizers() const {
        ~SanitizerKind::Function) |
       (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
       SanitizerKind::CFICastStrict | SanitizerKind::FloatDivideByZero |
-      SanitizerKind::KCFI | SanitizerKind::UnsignedIntegerOverflow |
+      SanitizerKind::UnsignedIntegerOverflow |
       SanitizerKind::UnsignedShiftBase | SanitizerKind::ImplicitConversion |
       SanitizerKind::Nullability | SanitizerKind::LocalBounds;
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().getArch() == llvm::Triple::arm || getTriple().isWasm() ||
       getTriple().isAArch64() || getTriple().isRISCV())
     Res |= SanitizerKind::CFIICall;
+  if (getTriple().getArch() == llvm::Triple::x86_64 ||
+      getTriple().isAArch64(64))
+    Res |= SanitizerKind::KCFI;
   if (getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().isAArch64(64) || getTriple().isRISCV())
     Res |= SanitizerKind::ShadowCallStack;

llvm/include/llvm/InitializePasses.h

@@ -258,7 +258,6 @@ void initializeLowerInvokeLegacyPassPass(PassRegistry&);
 void initializeLowerSwitchLegacyPassPass(PassRegistry &);
 void initializeLowerMatrixIntrinsicsLegacyPassPass(PassRegistry &);
 void initializeLowerMatrixIntrinsicsMinimalLegacyPassPass(PassRegistry &);
-void initializeKCFIPass(PassRegistry &);
 void initializeMIRAddFSDiscriminatorsPass(PassRegistry &);
 void initializeMIRCanonicalizerPass(PassRegistry &);
 void initializeMIRNamerPass(PassRegistry &);

llvm/include/llvm/Transforms/Instrumentation/KCFI.h

@@ -137,7 +137,6 @@
 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/InstrOrderFile.h"
 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
-#include "llvm/Transforms/Instrumentation/KCFI.h"
 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
 #include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"

llvm/lib/Passes/PassBuilder.cpp

@@ -322,7 +322,6 @@ FUNCTION_PASS("nary-reassociate", NaryReassociatePass())
 FUNCTION_PASS("newgvn", NewGVNPass())
 FUNCTION_PASS("jump-threading", JumpThreadingPass())
 FUNCTION_PASS("partially-inline-libcalls", PartiallyInlineLibCallsPass())
-FUNCTION_PASS("kcfi", KCFIPass(TM))
 FUNCTION_PASS("lcssa", LCSSAPass())
 FUNCTION_PASS("loop-data-prefetch", LoopDataPrefetchPass())
 FUNCTION_PASS("loop-load-elim", LoopLoadEliminationPass())

llvm/lib/Passes/PassRegistry.def

@@ -11,7 +11,6 @@ add_llvm_component_library(LLVMInstrumentation
   Instrumentation.cpp
   InstrOrderFile.cpp
   InstrProfiling.cpp
-  KCFI.cpp
   PGOInstrumentation.cpp
   PGOMemOPSizeOpt.cpp
   PoisonChecking.cpp