Revert "[CodeGen] Async unwind - add a pass to fix CFI information"

This reverts commit 980c3e6. This commit had failing tests with clang crashing across various AArch64/Linux buildots. https://lab.llvm.org/buildbot/#/builders/179/builds/3346 Differential Revision: https://reviews.llvm.org/D114545
llvm · Apr 5, 2022 · 0320115 · 0320115
1 parent 64f659b
commit 0320115
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Showing 27 changed files with 15 additions and 959 deletions.
diff --git a/llvm/include/llvm/CodeGen/CFIFixup.h b/llvm/include/llvm/CodeGen/CFIFixup.h
diff --git a/llvm/include/llvm/CodeGen/Passes.h b/llvm/include/llvm/CodeGen/Passes.h
@@ -494,9 +494,6 @@ namespace llvm {
   // This pass expands indirectbr instructions.
   FunctionPass *createIndirectBrExpandPass();
 
-  /// Creates CFI Fixup pass. \see CFIFixup.cpp
-  FunctionPass *createCFIFixup();
-
   /// Creates CFI Instruction Inserter pass. \see CFIInstrInserter.cpp
   FunctionPass *createCFIInstrInserter();
 

diff --git a/llvm/include/llvm/CodeGen/TargetFrameLowering.h b/llvm/include/llvm/CodeGen/TargetFrameLowering.h
@@ -223,14 +223,6 @@ class TargetFrameLowering {
   emitCalleeSavedFrameMovesFullCFA(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MBBI) const {}
 
-  /// Returns true if we may need to fix the unwind infportmation for the
-  /// function.
-  virtual bool enableCFIFixup(MachineFunction &MF) const;
-
-  /// Emit CFI instructions that recreate the state of the unwind information
-  /// upon fucntion entry.
-  virtual void resetCFIToInitialState(MachineBasicBlock &MBB) const {}
-
   /// Replace a StackProbe stub (if any) with the actual probe code inline
   virtual void inlineStackProbe(MachineFunction &MF,
                                 MachineBasicBlock &PrologueMBB) const {}

diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
@@ -103,7 +103,6 @@ void initializeCFGSimplifyPassPass(PassRegistry&);
 void initializeCFGuardPass(PassRegistry&);
 void initializeCFGuardLongjmpPass(PassRegistry&);
 void initializeCFGViewerLegacyPassPass(PassRegistry&);
-void initializeCFIFixupPass(PassRegistry&);
 void initializeCFIInstrInserterPass(PassRegistry&);
 void initializeCFLAndersAAWrapperPassPass(PassRegistry&);
 void initializeCFLSteensAAWrapperPassPass(PassRegistry&);

diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
@@ -257,8 +257,6 @@ class TargetMachine {
     Options.SupportsDebugEntryValues = Enable;
   }
 
-  void setCFIFixup(bool Enable) { Options.EnableCFIFixup = Enable; }
-
   bool getAIXExtendedAltivecABI() const {
     return Options.EnableAIXExtendedAltivecABI;
   }

diff --git a/llvm/include/llvm/Target/TargetOptions.h b/llvm/include/llvm/Target/TargetOptions.h
@@ -144,7 +144,6 @@ namespace llvm {
           ValueTrackingVariableLocations(false), ForceDwarfFrameSection(false),
           XRayOmitFunctionIndex(false), DebugStrictDwarf(false),
           Hotpatch(false), PPCGenScalarMASSEntries(false), JMCInstrument(false),
-          EnableCFIFixup(false),
           FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}
 
     /// DisableFramePointerElim - This returns true if frame pointer elimination
@@ -357,9 +356,6 @@ namespace llvm {
     /// Enable JustMyCode instrumentation.
     unsigned JMCInstrument : 1;
 
-    /// Enable the CFIFixup pass.
-    unsigned EnableCFIFixup : 1;
-
     /// Name of the stack usage file (i.e., .su file) if user passes
     /// -fstack-usage. If empty, it can be implied that -fstack-usage is not
     /// passed on the command line.

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -273,12 +273,6 @@ void AsmPrinter::emitCFIInstruction(const MCCFIInstruction &Inst) const {
   case MCCFIInstruction::OpUndefined:
     OutStreamer->emitCFIUndefined(Inst.getRegister());
     break;
-  case MCCFIInstruction::OpRememberState:
-    OutStreamer->emitCFIRememberState();
-    break;
-  case MCCFIInstruction::OpRestoreState:
-    OutStreamer->emitCFIRestoreState();
-    break;
   }
 }
 

diff --git a/llvm/lib/CodeGen/CFIFixup.cpp b/llvm/lib/CodeGen/CFIFixup.cpp
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
@@ -38,7 +38,6 @@ add_llvm_component_library(LLVMCodeGen
   CalcSpillWeights.cpp
   CallingConvLower.cpp
   CFGuardLongjmp.cpp
-  CFIFixup.cpp
   CFIInstrInserter.cpp
   CodeGen.cpp
   CodeGenCommonISel.cpp

diff --git a/llvm/lib/CodeGen/CodeGen.cpp b/llvm/lib/CodeGen/CodeGen.cpp
@@ -24,7 +24,6 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeBranchFolderPassPass(Registry);
   initializeBranchRelaxationPass(Registry);
   initializeCFGuardLongjmpPass(Registry);
-  initializeCFIFixupPass(Registry);
   initializeCFIInstrInserterPass(Registry);
   initializeCheckDebugMachineModulePass(Registry);
   initializeCodeGenPreparePass(Registry);

diff --git a/llvm/lib/CodeGen/TailDuplicator.cpp b/llvm/lib/CodeGen/TailDuplicator.cpp
@@ -383,9 +383,8 @@ void TailDuplicator::duplicateInstruction(
   // Allow duplication of CFI instructions.
   if (MI->isCFIInstruction()) {
     BuildMI(*PredBB, PredBB->end(), PredBB->findDebugLoc(PredBB->begin()),
-            TII->get(TargetOpcode::CFI_INSTRUCTION))
-        .addCFIIndex(MI->getOperand(0).getCFIIndex())
-        .setMIFlags(MI->getFlags());
+      TII->get(TargetOpcode::CFI_INSTRUCTION)).addCFIIndex(
+      MI->getOperand(0).getCFIIndex());
     return;
   }
   MachineInstr &NewMI = TII->duplicate(*PredBB, PredBB->end(), *MI);

diff --git a/llvm/lib/CodeGen/TargetFrameLoweringImpl.cpp b/llvm/lib/CodeGen/TargetFrameLoweringImpl.cpp
@@ -21,8 +21,6 @@
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstrTypes.h"
-#include "llvm/MC/MCAsmInfo.h"
-#include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
@@ -38,11 +36,6 @@ bool TargetFrameLowering::enableCalleeSaveSkip(const MachineFunction &MF) const
   return false;
 }
 
-bool TargetFrameLowering::enableCFIFixup(MachineFunction &MF) const {
-  return MF.needsFrameMoves() &&
-         !MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
-}
-
 /// Returns the displacement from the frame register to the stack
 /// frame of the specified index, along with the frame register used
 /// (in output arg FrameReg). This is the default implementation which

diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -138,11 +138,6 @@ static cl::opt<RunOutliner> EnableMachineOutliner(
                           "Disable all outlining"),
                // Sentinel value for unspecified option.
                clEnumValN(RunOutliner::AlwaysOutline, "", "")));
-// Disable the pass to fix unwind information. Whether the pass is included in
-// the pipeline is controlled via the target options, this option serves as
-// manual override.
-static cl::opt<bool> DisableCFIFixup("disable-cfi-fixup", cl::Hidden,
-                                     cl::desc("Disable the CFI fixup pass"));
 // Enable or disable FastISel. Both options are needed, because
 // FastISel is enabled by default with -fast, and we wish to be
 // able to enable or disable fast-isel independently from -O0.
@@ -1280,9 +1275,6 @@ void TargetPassConfig::addMachinePasses() {
     addPass(createMachineFunctionSplitterPass());
   }
 
-  if (!DisableCFIFixup && TM->Options.EnableCFIFixup)
-    addPass(createCFIFixup());
-
   // Add passes that directly emit MI after all other MI passes.
   addPreEmitPass2();