llvm-project/llvm/lib/CodeGen/MIRPrinter.cpp
Sami Tolvanen cff5bef948 KCFI sanitizer
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.

Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.

KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.

A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:

```
.c:
  int f(void);
  int (*p)(void) = f;
  p();

.s:
  .4byte __kcfi_typeid_f
  .global f
  f:
    ...
```

Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.

As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.

Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.

Relands 67504c95494ff05be2a613129110c9bcf17f6c13 with a fix for
32-bit builds.

Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay

Differential Revision: https://reviews.llvm.org/D119296
2022-08-24 22:41:38 +00:00

961 lines
34 KiB
C++

//===- MIRPrinter.cpp - MIR serialization format printer ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the class that prints out the LLVM IR and machine
// functions using the MIR serialization format.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MIRPrinter.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/MIRYamlMapping.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineModuleSlotTracker.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSlotTracker.h"
#include "llvm/IR/Value.h"
#include "llvm/MC/LaneBitmask.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/LowLevelTypeImpl.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cinttypes>
#include <cstdint>
#include <iterator>
#include <string>
#include <utility>
#include <vector>
using namespace llvm;
static cl::opt<bool> SimplifyMIR(
"simplify-mir", cl::Hidden,
cl::desc("Leave out unnecessary information when printing MIR"));
static cl::opt<bool> PrintLocations("mir-debug-loc", cl::Hidden, cl::init(true),
cl::desc("Print MIR debug-locations"));
namespace {
/// This structure describes how to print out stack object references.
struct FrameIndexOperand {
std::string Name;
unsigned ID;
bool IsFixed;
FrameIndexOperand(StringRef Name, unsigned ID, bool IsFixed)
: Name(Name.str()), ID(ID), IsFixed(IsFixed) {}
/// Return an ordinary stack object reference.
static FrameIndexOperand create(StringRef Name, unsigned ID) {
return FrameIndexOperand(Name, ID, /*IsFixed=*/false);
}
/// Return a fixed stack object reference.
static FrameIndexOperand createFixed(unsigned ID) {
return FrameIndexOperand("", ID, /*IsFixed=*/true);
}
};
} // end anonymous namespace
namespace llvm {
/// This class prints out the machine functions using the MIR serialization
/// format.
class MIRPrinter {
raw_ostream &OS;
DenseMap<const uint32_t *, unsigned> RegisterMaskIds;
/// Maps from stack object indices to operand indices which will be used when
/// printing frame index machine operands.
DenseMap<int, FrameIndexOperand> StackObjectOperandMapping;
public:
MIRPrinter(raw_ostream &OS) : OS(OS) {}
void print(const MachineFunction &MF);
void convert(yaml::MachineFunction &MF, const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI);
void convert(ModuleSlotTracker &MST, yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI);
void convert(yaml::MachineFunction &MF,
const MachineConstantPool &ConstantPool);
void convert(ModuleSlotTracker &MST, yaml::MachineJumpTable &YamlJTI,
const MachineJumpTableInfo &JTI);
void convertStackObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF, ModuleSlotTracker &MST);
void convertCallSiteObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST);
void convertMachineMetadataNodes(yaml::MachineFunction &YMF,
const MachineFunction &MF,
MachineModuleSlotTracker &MST);
private:
void initRegisterMaskIds(const MachineFunction &MF);
};
/// This class prints out the machine instructions using the MIR serialization
/// format.
class MIPrinter {
raw_ostream &OS;
ModuleSlotTracker &MST;
const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds;
const DenseMap<int, FrameIndexOperand> &StackObjectOperandMapping;
/// Synchronization scope names registered with LLVMContext.
SmallVector<StringRef, 8> SSNs;
bool canPredictBranchProbabilities(const MachineBasicBlock &MBB) const;
bool canPredictSuccessors(const MachineBasicBlock &MBB) const;
public:
MIPrinter(raw_ostream &OS, ModuleSlotTracker &MST,
const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds,
const DenseMap<int, FrameIndexOperand> &StackObjectOperandMapping)
: OS(OS), MST(MST), RegisterMaskIds(RegisterMaskIds),
StackObjectOperandMapping(StackObjectOperandMapping) {}
void print(const MachineBasicBlock &MBB);
void print(const MachineInstr &MI);
void printStackObjectReference(int FrameIndex);
void print(const MachineInstr &MI, unsigned OpIdx,
const TargetRegisterInfo *TRI, const TargetInstrInfo *TII,
bool ShouldPrintRegisterTies, LLT TypeToPrint,
bool PrintDef = true);
};
} // end namespace llvm
namespace llvm {
namespace yaml {
/// This struct serializes the LLVM IR module.
template <> struct BlockScalarTraits<Module> {
static void output(const Module &Mod, void *Ctxt, raw_ostream &OS) {
Mod.print(OS, nullptr);
}
static StringRef input(StringRef Str, void *Ctxt, Module &Mod) {
llvm_unreachable("LLVM Module is supposed to be parsed separately");
return "";
}
};
} // end namespace yaml
} // end namespace llvm
static void printRegMIR(unsigned Reg, yaml::StringValue &Dest,
const TargetRegisterInfo *TRI) {
raw_string_ostream OS(Dest.Value);
OS << printReg(Reg, TRI);
}
void MIRPrinter::print(const MachineFunction &MF) {
initRegisterMaskIds(MF);
yaml::MachineFunction YamlMF;
YamlMF.Name = MF.getName();
YamlMF.Alignment = MF.getAlignment();
YamlMF.ExposesReturnsTwice = MF.exposesReturnsTwice();
YamlMF.HasWinCFI = MF.hasWinCFI();
YamlMF.CallsEHReturn = MF.callsEHReturn();
YamlMF.CallsUnwindInit = MF.callsUnwindInit();
YamlMF.HasEHCatchret = MF.hasEHCatchret();
YamlMF.HasEHScopes = MF.hasEHScopes();
YamlMF.HasEHFunclets = MF.hasEHFunclets();
YamlMF.Legalized = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::Legalized);
YamlMF.RegBankSelected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::RegBankSelected);
YamlMF.Selected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::Selected);
YamlMF.FailedISel = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::FailedISel);
YamlMF.FailsVerification = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::FailsVerification);
YamlMF.TracksDebugUserValues = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::TracksDebugUserValues);
convert(YamlMF, MF.getRegInfo(), MF.getSubtarget().getRegisterInfo());
MachineModuleSlotTracker MST(&MF);
MST.incorporateFunction(MF.getFunction());
convert(MST, YamlMF.FrameInfo, MF.getFrameInfo());
convertStackObjects(YamlMF, MF, MST);
convertCallSiteObjects(YamlMF, MF, MST);
for (const auto &Sub : MF.DebugValueSubstitutions) {
const auto &SubSrc = Sub.Src;
const auto &SubDest = Sub.Dest;
YamlMF.DebugValueSubstitutions.push_back({SubSrc.first, SubSrc.second,
SubDest.first,
SubDest.second,
Sub.Subreg});
}
if (const auto *ConstantPool = MF.getConstantPool())
convert(YamlMF, *ConstantPool);
if (const auto *JumpTableInfo = MF.getJumpTableInfo())
convert(MST, YamlMF.JumpTableInfo, *JumpTableInfo);
const TargetMachine &TM = MF.getTarget();
YamlMF.MachineFuncInfo =
std::unique_ptr<yaml::MachineFunctionInfo>(TM.convertFuncInfoToYAML(MF));
raw_string_ostream StrOS(YamlMF.Body.Value.Value);
bool IsNewlineNeeded = false;
for (const auto &MBB : MF) {
if (IsNewlineNeeded)
StrOS << "\n";
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.print(MBB);
IsNewlineNeeded = true;
}
StrOS.flush();
// Convert machine metadata collected during the print of the machine
// function.
convertMachineMetadataNodes(YamlMF, MF, MST);
yaml::Output Out(OS);
if (!SimplifyMIR)
Out.setWriteDefaultValues(true);
Out << YamlMF;
}
static void printCustomRegMask(const uint32_t *RegMask, raw_ostream &OS,
const TargetRegisterInfo *TRI) {
assert(RegMask && "Can't print an empty register mask");
OS << StringRef("CustomRegMask(");
bool IsRegInRegMaskFound = false;
for (int I = 0, E = TRI->getNumRegs(); I < E; I++) {
// Check whether the register is asserted in regmask.
if (RegMask[I / 32] & (1u << (I % 32))) {
if (IsRegInRegMaskFound)
OS << ',';
OS << printReg(I, TRI);
IsRegInRegMaskFound = true;
}
}
OS << ')';
}
static void printRegClassOrBank(unsigned Reg, yaml::StringValue &Dest,
const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI) {
raw_string_ostream OS(Dest.Value);
OS << printRegClassOrBank(Reg, RegInfo, TRI);
}
template <typename T>
static void
printStackObjectDbgInfo(const MachineFunction::VariableDbgInfo &DebugVar,
T &Object, ModuleSlotTracker &MST) {
std::array<std::string *, 3> Outputs{{&Object.DebugVar.Value,
&Object.DebugExpr.Value,
&Object.DebugLoc.Value}};
std::array<const Metadata *, 3> Metas{{DebugVar.Var,
DebugVar.Expr,
DebugVar.Loc}};
for (unsigned i = 0; i < 3; ++i) {
raw_string_ostream StrOS(*Outputs[i]);
Metas[i]->printAsOperand(StrOS, MST);
}
}
void MIRPrinter::convert(yaml::MachineFunction &MF,
const MachineRegisterInfo &RegInfo,
const TargetRegisterInfo *TRI) {
MF.TracksRegLiveness = RegInfo.tracksLiveness();
// Print the virtual register definitions.
for (unsigned I = 0, E = RegInfo.getNumVirtRegs(); I < E; ++I) {
unsigned Reg = Register::index2VirtReg(I);
yaml::VirtualRegisterDefinition VReg;
VReg.ID = I;
if (RegInfo.getVRegName(Reg) != "")
continue;
::printRegClassOrBank(Reg, VReg.Class, RegInfo, TRI);
unsigned PreferredReg = RegInfo.getSimpleHint(Reg);
if (PreferredReg)
printRegMIR(PreferredReg, VReg.PreferredRegister, TRI);
MF.VirtualRegisters.push_back(VReg);
}
// Print the live ins.
for (std::pair<unsigned, unsigned> LI : RegInfo.liveins()) {
yaml::MachineFunctionLiveIn LiveIn;
printRegMIR(LI.first, LiveIn.Register, TRI);
if (LI.second)
printRegMIR(LI.second, LiveIn.VirtualRegister, TRI);
MF.LiveIns.push_back(LiveIn);
}
// Prints the callee saved registers.
if (RegInfo.isUpdatedCSRsInitialized()) {
const MCPhysReg *CalleeSavedRegs = RegInfo.getCalleeSavedRegs();
std::vector<yaml::FlowStringValue> CalleeSavedRegisters;
for (const MCPhysReg *I = CalleeSavedRegs; *I; ++I) {
yaml::FlowStringValue Reg;
printRegMIR(*I, Reg, TRI);
CalleeSavedRegisters.push_back(Reg);
}
MF.CalleeSavedRegisters = CalleeSavedRegisters;
}
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI) {
YamlMFI.IsFrameAddressTaken = MFI.isFrameAddressTaken();
YamlMFI.IsReturnAddressTaken = MFI.isReturnAddressTaken();
YamlMFI.HasStackMap = MFI.hasStackMap();
YamlMFI.HasPatchPoint = MFI.hasPatchPoint();
YamlMFI.StackSize = MFI.getStackSize();
YamlMFI.OffsetAdjustment = MFI.getOffsetAdjustment();
YamlMFI.MaxAlignment = MFI.getMaxAlign().value();
YamlMFI.AdjustsStack = MFI.adjustsStack();
YamlMFI.HasCalls = MFI.hasCalls();
YamlMFI.MaxCallFrameSize = MFI.isMaxCallFrameSizeComputed()
? MFI.getMaxCallFrameSize() : ~0u;
YamlMFI.CVBytesOfCalleeSavedRegisters =
MFI.getCVBytesOfCalleeSavedRegisters();
YamlMFI.HasOpaqueSPAdjustment = MFI.hasOpaqueSPAdjustment();
YamlMFI.HasVAStart = MFI.hasVAStart();
YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
YamlMFI.HasTailCall = MFI.hasTailCall();
YamlMFI.LocalFrameSize = MFI.getLocalFrameSize();
if (MFI.getSavePoint()) {
raw_string_ostream StrOS(YamlMFI.SavePoint.Value);
StrOS << printMBBReference(*MFI.getSavePoint());
}
if (MFI.getRestorePoint()) {
raw_string_ostream StrOS(YamlMFI.RestorePoint.Value);
StrOS << printMBBReference(*MFI.getRestorePoint());
}
}
void MIRPrinter::convertStackObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST) {
const MachineFrameInfo &MFI = MF.getFrameInfo();
const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
// Process fixed stack objects.
assert(YMF.FixedStackObjects.empty());
SmallVector<int, 32> FixedStackObjectsIdx;
const int BeginIdx = MFI.getObjectIndexBegin();
if (BeginIdx < 0)
FixedStackObjectsIdx.reserve(-BeginIdx);
unsigned ID = 0;
for (int I = BeginIdx; I < 0; ++I, ++ID) {
FixedStackObjectsIdx.push_back(-1); // Fill index for possible dead.
if (MFI.isDeadObjectIndex(I))
continue;
yaml::FixedMachineStackObject YamlObject;
YamlObject.ID = ID;
YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
? yaml::FixedMachineStackObject::SpillSlot
: yaml::FixedMachineStackObject::DefaultType;
YamlObject.Offset = MFI.getObjectOffset(I);
YamlObject.Size = MFI.getObjectSize(I);
YamlObject.Alignment = MFI.getObjectAlign(I);
YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
YamlObject.IsImmutable = MFI.isImmutableObjectIndex(I);
YamlObject.IsAliased = MFI.isAliasedObjectIndex(I);
// Save the ID' position in FixedStackObjects storage vector.
FixedStackObjectsIdx[ID] = YMF.FixedStackObjects.size();
YMF.FixedStackObjects.push_back(YamlObject);
StackObjectOperandMapping.insert(
std::make_pair(I, FrameIndexOperand::createFixed(ID)));
}
// Process ordinary stack objects.
assert(YMF.StackObjects.empty());
SmallVector<unsigned, 32> StackObjectsIdx;
const int EndIdx = MFI.getObjectIndexEnd();
if (EndIdx > 0)
StackObjectsIdx.reserve(EndIdx);
ID = 0;
for (int I = 0; I < EndIdx; ++I, ++ID) {
StackObjectsIdx.push_back(-1); // Fill index for possible dead.
if (MFI.isDeadObjectIndex(I))
continue;
yaml::MachineStackObject YamlObject;
YamlObject.ID = ID;
if (const auto *Alloca = MFI.getObjectAllocation(I))
YamlObject.Name.Value = std::string(
Alloca->hasName() ? Alloca->getName() : "");
YamlObject.Type = MFI.isSpillSlotObjectIndex(I)
? yaml::MachineStackObject::SpillSlot
: MFI.isVariableSizedObjectIndex(I)
? yaml::MachineStackObject::VariableSized
: yaml::MachineStackObject::DefaultType;
YamlObject.Offset = MFI.getObjectOffset(I);
YamlObject.Size = MFI.getObjectSize(I);
YamlObject.Alignment = MFI.getObjectAlign(I);
YamlObject.StackID = (TargetStackID::Value)MFI.getStackID(I);
// Save the ID' position in StackObjects storage vector.
StackObjectsIdx[ID] = YMF.StackObjects.size();
YMF.StackObjects.push_back(YamlObject);
StackObjectOperandMapping.insert(std::make_pair(
I, FrameIndexOperand::create(YamlObject.Name.Value, ID)));
}
for (const auto &CSInfo : MFI.getCalleeSavedInfo()) {
const int FrameIdx = CSInfo.getFrameIdx();
if (!CSInfo.isSpilledToReg() && MFI.isDeadObjectIndex(FrameIdx))
continue;
yaml::StringValue Reg;
printRegMIR(CSInfo.getReg(), Reg, TRI);
if (!CSInfo.isSpilledToReg()) {
assert(FrameIdx >= MFI.getObjectIndexBegin() &&
FrameIdx < MFI.getObjectIndexEnd() &&
"Invalid stack object index");
if (FrameIdx < 0) { // Negative index means fixed objects.
auto &Object =
YMF.FixedStackObjects
[FixedStackObjectsIdx[FrameIdx + MFI.getNumFixedObjects()]];
Object.CalleeSavedRegister = Reg;
Object.CalleeSavedRestored = CSInfo.isRestored();
} else {
auto &Object = YMF.StackObjects[StackObjectsIdx[FrameIdx]];
Object.CalleeSavedRegister = Reg;
Object.CalleeSavedRestored = CSInfo.isRestored();
}
}
}
for (unsigned I = 0, E = MFI.getLocalFrameObjectCount(); I < E; ++I) {
auto LocalObject = MFI.getLocalFrameObjectMap(I);
assert(LocalObject.first >= 0 && "Expected a locally mapped stack object");
YMF.StackObjects[StackObjectsIdx[LocalObject.first]].LocalOffset =
LocalObject.second;
}
// Print the stack object references in the frame information class after
// converting the stack objects.
if (MFI.hasStackProtectorIndex()) {
raw_string_ostream StrOS(YMF.FrameInfo.StackProtector.Value);
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.printStackObjectReference(MFI.getStackProtectorIndex());
}
if (MFI.hasFunctionContextIndex()) {
raw_string_ostream StrOS(YMF.FrameInfo.FunctionContext.Value);
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.printStackObjectReference(MFI.getFunctionContextIndex());
}
// Print the debug variable information.
for (const MachineFunction::VariableDbgInfo &DebugVar :
MF.getVariableDbgInfo()) {
assert(DebugVar.Slot >= MFI.getObjectIndexBegin() &&
DebugVar.Slot < MFI.getObjectIndexEnd() &&
"Invalid stack object index");
if (DebugVar.Slot < 0) { // Negative index means fixed objects.
auto &Object =
YMF.FixedStackObjects[FixedStackObjectsIdx[DebugVar.Slot +
MFI.getNumFixedObjects()]];
printStackObjectDbgInfo(DebugVar, Object, MST);
} else {
auto &Object = YMF.StackObjects[StackObjectsIdx[DebugVar.Slot]];
printStackObjectDbgInfo(DebugVar, Object, MST);
}
}
}
void MIRPrinter::convertCallSiteObjects(yaml::MachineFunction &YMF,
const MachineFunction &MF,
ModuleSlotTracker &MST) {
const auto *TRI = MF.getSubtarget().getRegisterInfo();
for (auto CSInfo : MF.getCallSitesInfo()) {
yaml::CallSiteInfo YmlCS;
yaml::CallSiteInfo::MachineInstrLoc CallLocation;
// Prepare instruction position.
MachineBasicBlock::const_instr_iterator CallI = CSInfo.first->getIterator();
CallLocation.BlockNum = CallI->getParent()->getNumber();
// Get call instruction offset from the beginning of block.
CallLocation.Offset =
std::distance(CallI->getParent()->instr_begin(), CallI);
YmlCS.CallLocation = CallLocation;
// Construct call arguments and theirs forwarding register info.
for (auto ArgReg : CSInfo.second) {
yaml::CallSiteInfo::ArgRegPair YmlArgReg;
YmlArgReg.ArgNo = ArgReg.ArgNo;
printRegMIR(ArgReg.Reg, YmlArgReg.Reg, TRI);
YmlCS.ArgForwardingRegs.emplace_back(YmlArgReg);
}
YMF.CallSitesInfo.push_back(YmlCS);
}
// Sort call info by position of call instructions.
llvm::sort(YMF.CallSitesInfo.begin(), YMF.CallSitesInfo.end(),
[](yaml::CallSiteInfo A, yaml::CallSiteInfo B) {
if (A.CallLocation.BlockNum == B.CallLocation.BlockNum)
return A.CallLocation.Offset < B.CallLocation.Offset;
return A.CallLocation.BlockNum < B.CallLocation.BlockNum;
});
}
void MIRPrinter::convertMachineMetadataNodes(yaml::MachineFunction &YMF,
const MachineFunction &MF,
MachineModuleSlotTracker &MST) {
MachineModuleSlotTracker::MachineMDNodeListType MDList;
MST.collectMachineMDNodes(MDList);
for (auto &MD : MDList) {
std::string NS;
raw_string_ostream StrOS(NS);
MD.second->print(StrOS, MST, MF.getFunction().getParent());
YMF.MachineMetadataNodes.push_back(StrOS.str());
}
}
void MIRPrinter::convert(yaml::MachineFunction &MF,
const MachineConstantPool &ConstantPool) {
unsigned ID = 0;
for (const MachineConstantPoolEntry &Constant : ConstantPool.getConstants()) {
std::string Str;
raw_string_ostream StrOS(Str);
if (Constant.isMachineConstantPoolEntry()) {
Constant.Val.MachineCPVal->print(StrOS);
} else {
Constant.Val.ConstVal->printAsOperand(StrOS);
}
yaml::MachineConstantPoolValue YamlConstant;
YamlConstant.ID = ID++;
YamlConstant.Value = StrOS.str();
YamlConstant.Alignment = Constant.getAlign();
YamlConstant.IsTargetSpecific = Constant.isMachineConstantPoolEntry();
MF.Constants.push_back(YamlConstant);
}
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineJumpTable &YamlJTI,
const MachineJumpTableInfo &JTI) {
YamlJTI.Kind = JTI.getEntryKind();
unsigned ID = 0;
for (const auto &Table : JTI.getJumpTables()) {
std::string Str;
yaml::MachineJumpTable::Entry Entry;
Entry.ID = ID++;
for (const auto *MBB : Table.MBBs) {
raw_string_ostream StrOS(Str);
StrOS << printMBBReference(*MBB);
Entry.Blocks.push_back(StrOS.str());
Str.clear();
}
YamlJTI.Entries.push_back(Entry);
}
}
void MIRPrinter::initRegisterMaskIds(const MachineFunction &MF) {
const auto *TRI = MF.getSubtarget().getRegisterInfo();
unsigned I = 0;
for (const uint32_t *Mask : TRI->getRegMasks())
RegisterMaskIds.insert(std::make_pair(Mask, I++));
}
void llvm::guessSuccessors(const MachineBasicBlock &MBB,
SmallVectorImpl<MachineBasicBlock*> &Result,
bool &IsFallthrough) {
SmallPtrSet<MachineBasicBlock*,8> Seen;
for (const MachineInstr &MI : MBB) {
if (MI.isPHI())
continue;
for (const MachineOperand &MO : MI.operands()) {
if (!MO.isMBB())
continue;
MachineBasicBlock *Succ = MO.getMBB();
auto RP = Seen.insert(Succ);
if (RP.second)
Result.push_back(Succ);
}
}
MachineBasicBlock::const_iterator I = MBB.getLastNonDebugInstr();
IsFallthrough = I == MBB.end() || !I->isBarrier();
}
bool
MIPrinter::canPredictBranchProbabilities(const MachineBasicBlock &MBB) const {
if (MBB.succ_size() <= 1)
return true;
if (!MBB.hasSuccessorProbabilities())
return true;
SmallVector<BranchProbability,8> Normalized(MBB.Probs.begin(),
MBB.Probs.end());
BranchProbability::normalizeProbabilities(Normalized.begin(),
Normalized.end());
SmallVector<BranchProbability,8> Equal(Normalized.size());
BranchProbability::normalizeProbabilities(Equal.begin(), Equal.end());
return std::equal(Normalized.begin(), Normalized.end(), Equal.begin());
}
bool MIPrinter::canPredictSuccessors(const MachineBasicBlock &MBB) const {
SmallVector<MachineBasicBlock*,8> GuessedSuccs;
bool GuessedFallthrough;
guessSuccessors(MBB, GuessedSuccs, GuessedFallthrough);
if (GuessedFallthrough) {
const MachineFunction &MF = *MBB.getParent();
MachineFunction::const_iterator NextI = std::next(MBB.getIterator());
if (NextI != MF.end()) {
MachineBasicBlock *Next = const_cast<MachineBasicBlock*>(&*NextI);
if (!is_contained(GuessedSuccs, Next))
GuessedSuccs.push_back(Next);
}
}
if (GuessedSuccs.size() != MBB.succ_size())
return false;
return std::equal(MBB.succ_begin(), MBB.succ_end(), GuessedSuccs.begin());
}
void MIPrinter::print(const MachineBasicBlock &MBB) {
assert(MBB.getNumber() >= 0 && "Invalid MBB number");
MBB.printName(OS,
MachineBasicBlock::PrintNameIr |
MachineBasicBlock::PrintNameAttributes,
&MST);
OS << ":\n";
bool HasLineAttributes = false;
// Print the successors
bool canPredictProbs = canPredictBranchProbabilities(MBB);
// Even if the list of successors is empty, if we cannot guess it,
// we need to print it to tell the parser that the list is empty.
// This is needed, because MI model unreachable as empty blocks
// with an empty successor list. If the parser would see that
// without the successor list, it would guess the code would
// fallthrough.
if ((!MBB.succ_empty() && !SimplifyMIR) || !canPredictProbs ||
!canPredictSuccessors(MBB)) {
OS.indent(2) << "successors: ";
for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
if (I != MBB.succ_begin())
OS << ", ";
OS << printMBBReference(**I);
if (!SimplifyMIR || !canPredictProbs)
OS << '('
<< format("0x%08" PRIx32, MBB.getSuccProbability(I).getNumerator())
<< ')';
}
OS << "\n";
HasLineAttributes = true;
}
// Print the live in registers.
const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
if (!MBB.livein_empty()) {
const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
OS.indent(2) << "liveins: ";
bool First = true;
for (const auto &LI : MBB.liveins_dbg()) {
if (!First)
OS << ", ";
First = false;
OS << printReg(LI.PhysReg, &TRI);
if (!LI.LaneMask.all())
OS << ":0x" << PrintLaneMask(LI.LaneMask);
}
OS << "\n";
HasLineAttributes = true;
}
if (HasLineAttributes)
OS << "\n";
bool IsInBundle = false;
for (auto I = MBB.instr_begin(), E = MBB.instr_end(); I != E; ++I) {
const MachineInstr &MI = *I;
if (IsInBundle && !MI.isInsideBundle()) {
OS.indent(2) << "}\n";
IsInBundle = false;
}
OS.indent(IsInBundle ? 4 : 2);
print(MI);
if (!IsInBundle && MI.getFlag(MachineInstr::BundledSucc)) {
OS << " {";
IsInBundle = true;
}
OS << "\n";
}
if (IsInBundle)
OS.indent(2) << "}\n";
}
void MIPrinter::print(const MachineInstr &MI) {
const auto *MF = MI.getMF();
const auto &MRI = MF->getRegInfo();
const auto &SubTarget = MF->getSubtarget();
const auto *TRI = SubTarget.getRegisterInfo();
assert(TRI && "Expected target register info");
const auto *TII = SubTarget.getInstrInfo();
assert(TII && "Expected target instruction info");
if (MI.isCFIInstruction())
assert(MI.getNumOperands() == 1 && "Expected 1 operand in CFI instruction");
SmallBitVector PrintedTypes(8);
bool ShouldPrintRegisterTies = MI.hasComplexRegisterTies();
unsigned I = 0, E = MI.getNumOperands();
for (; I < E && MI.getOperand(I).isReg() && MI.getOperand(I).isDef() &&
!MI.getOperand(I).isImplicit();
++I) {
if (I)
OS << ", ";
print(MI, I, TRI, TII, ShouldPrintRegisterTies,
MI.getTypeToPrint(I, PrintedTypes, MRI),
/*PrintDef=*/false);
}
if (I)
OS << " = ";
if (MI.getFlag(MachineInstr::FrameSetup))
OS << "frame-setup ";
if (MI.getFlag(MachineInstr::FrameDestroy))
OS << "frame-destroy ";
if (MI.getFlag(MachineInstr::FmNoNans))
OS << "nnan ";
if (MI.getFlag(MachineInstr::FmNoInfs))
OS << "ninf ";
if (MI.getFlag(MachineInstr::FmNsz))
OS << "nsz ";
if (MI.getFlag(MachineInstr::FmArcp))
OS << "arcp ";
if (MI.getFlag(MachineInstr::FmContract))
OS << "contract ";
if (MI.getFlag(MachineInstr::FmAfn))
OS << "afn ";
if (MI.getFlag(MachineInstr::FmReassoc))
OS << "reassoc ";
if (MI.getFlag(MachineInstr::NoUWrap))
OS << "nuw ";
if (MI.getFlag(MachineInstr::NoSWrap))
OS << "nsw ";
if (MI.getFlag(MachineInstr::IsExact))
OS << "exact ";
if (MI.getFlag(MachineInstr::NoFPExcept))
OS << "nofpexcept ";
if (MI.getFlag(MachineInstr::NoMerge))
OS << "nomerge ";
OS << TII->getName(MI.getOpcode());
if (I < E)
OS << ' ';
bool NeedComma = false;
for (; I < E; ++I) {
if (NeedComma)
OS << ", ";
print(MI, I, TRI, TII, ShouldPrintRegisterTies,
MI.getTypeToPrint(I, PrintedTypes, MRI));
NeedComma = true;
}
// Print any optional symbols attached to this instruction as-if they were
// operands.
if (MCSymbol *PreInstrSymbol = MI.getPreInstrSymbol()) {
if (NeedComma)
OS << ',';
OS << " pre-instr-symbol ";
MachineOperand::printSymbol(OS, *PreInstrSymbol);
NeedComma = true;
}
if (MCSymbol *PostInstrSymbol = MI.getPostInstrSymbol()) {
if (NeedComma)
OS << ',';
OS << " post-instr-symbol ";
MachineOperand::printSymbol(OS, *PostInstrSymbol);
NeedComma = true;
}
if (MDNode *HeapAllocMarker = MI.getHeapAllocMarker()) {
if (NeedComma)
OS << ',';
OS << " heap-alloc-marker ";
HeapAllocMarker->printAsOperand(OS, MST);
NeedComma = true;
}
if (uint32_t CFIType = MI.getCFIType()) {
if (NeedComma)
OS << ',';
OS << " cfi-type " << CFIType;
NeedComma = true;
}
if (auto Num = MI.peekDebugInstrNum()) {
if (NeedComma)
OS << ',';
OS << " debug-instr-number " << Num;
NeedComma = true;
}
if (PrintLocations) {
if (const DebugLoc &DL = MI.getDebugLoc()) {
if (NeedComma)
OS << ',';
OS << " debug-location ";
DL->printAsOperand(OS, MST);
}
}
if (!MI.memoperands_empty()) {
OS << " :: ";
const LLVMContext &Context = MF->getFunction().getContext();
const MachineFrameInfo &MFI = MF->getFrameInfo();
bool NeedComma = false;
for (const auto *Op : MI.memoperands()) {
if (NeedComma)
OS << ", ";
Op->print(OS, MST, SSNs, Context, &MFI, TII);
NeedComma = true;
}
}
}
void MIPrinter::printStackObjectReference(int FrameIndex) {
auto ObjectInfo = StackObjectOperandMapping.find(FrameIndex);
assert(ObjectInfo != StackObjectOperandMapping.end() &&
"Invalid frame index");
const FrameIndexOperand &Operand = ObjectInfo->second;
MachineOperand::printStackObjectReference(OS, Operand.ID, Operand.IsFixed,
Operand.Name);
}
static std::string formatOperandComment(std::string Comment) {
if (Comment.empty())
return Comment;
return std::string(" /* " + Comment + " */");
}
void MIPrinter::print(const MachineInstr &MI, unsigned OpIdx,
const TargetRegisterInfo *TRI,
const TargetInstrInfo *TII,
bool ShouldPrintRegisterTies, LLT TypeToPrint,
bool PrintDef) {
const MachineOperand &Op = MI.getOperand(OpIdx);
std::string MOComment = TII->createMIROperandComment(MI, Op, OpIdx, TRI);
switch (Op.getType()) {
case MachineOperand::MO_Immediate:
if (MI.isOperandSubregIdx(OpIdx)) {
MachineOperand::printTargetFlags(OS, Op);
MachineOperand::printSubRegIdx(OS, Op.getImm(), TRI);
break;
}
[[fallthrough]];
case MachineOperand::MO_Register:
case MachineOperand::MO_CImmediate:
case MachineOperand::MO_FPImmediate:
case MachineOperand::MO_MachineBasicBlock:
case MachineOperand::MO_ConstantPoolIndex:
case MachineOperand::MO_TargetIndex:
case MachineOperand::MO_JumpTableIndex:
case MachineOperand::MO_ExternalSymbol:
case MachineOperand::MO_GlobalAddress:
case MachineOperand::MO_RegisterLiveOut:
case MachineOperand::MO_Metadata:
case MachineOperand::MO_MCSymbol:
case MachineOperand::MO_CFIIndex:
case MachineOperand::MO_IntrinsicID:
case MachineOperand::MO_Predicate:
case MachineOperand::MO_BlockAddress:
case MachineOperand::MO_ShuffleMask: {
unsigned TiedOperandIdx = 0;
if (ShouldPrintRegisterTies && Op.isReg() && Op.isTied() && !Op.isDef())
TiedOperandIdx = Op.getParent()->findTiedOperandIdx(OpIdx);
const TargetIntrinsicInfo *TII = MI.getMF()->getTarget().getIntrinsicInfo();
Op.print(OS, MST, TypeToPrint, OpIdx, PrintDef, /*IsStandalone=*/false,
ShouldPrintRegisterTies, TiedOperandIdx, TRI, TII);
OS << formatOperandComment(MOComment);
break;
}
case MachineOperand::MO_FrameIndex:
printStackObjectReference(Op.getIndex());
break;
case MachineOperand::MO_RegisterMask: {
auto RegMaskInfo = RegisterMaskIds.find(Op.getRegMask());
if (RegMaskInfo != RegisterMaskIds.end())
OS << StringRef(TRI->getRegMaskNames()[RegMaskInfo->second]).lower();
else
printCustomRegMask(Op.getRegMask(), OS, TRI);
break;
}
}
}
void MIRFormatter::printIRValue(raw_ostream &OS, const Value &V,
ModuleSlotTracker &MST) {
if (isa<GlobalValue>(V)) {
V.printAsOperand(OS, /*PrintType=*/false, MST);
return;
}
if (isa<Constant>(V)) {
// Machine memory operands can load/store to/from constant value pointers.
OS << '`';
V.printAsOperand(OS, /*PrintType=*/true, MST);
OS << '`';
return;
}
OS << "%ir.";
if (V.hasName()) {
printLLVMNameWithoutPrefix(OS, V.getName());
return;
}
int Slot = MST.getCurrentFunction() ? MST.getLocalSlot(&V) : -1;
MachineOperand::printIRSlotNumber(OS, Slot);
}
void llvm::printMIR(raw_ostream &OS, const Module &M) {
yaml::Output Out(OS);
Out << const_cast<Module &>(M);
}
void llvm::printMIR(raw_ostream &OS, const MachineFunction &MF) {
MIRPrinter Printer(OS);
Printer.print(MF);
}