BPFCORE.h

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//===- BPFCORE.h - Common info for Compile-Once Run-EveryWhere  -*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_LIB_TARGET_BPF_BPFCORE_H
#define LLVM_LIB_TARGET_BPF_BPFCORE_H
 
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Support/ErrorHandling.h"
 
namespace llvm {
 
class BasicBlock;
class Instruction;
class Module;
 
/// Return the bit offset used to order an element of a BTF structure record.
inline uint64_t getBTFRecordElementOffset(const DINode *Element) {
  switch (Element->getTag()) {
  case dwarf::DW_TAG_member:
    return cast<DIDerivedType>(Element)->getOffsetInBits();
  case dwarf::DW_TAG_variant_part:
    return cast<DICompositeType>(Element)->getOffsetInBits();
  default:
    llvm_unreachable("Unexpected DI tag of a struct element");
  }
}
 
class BPFCoreSharedInfo {
public:
  enum BTFTypeIdFlag : uint32_t {
    BTF_TYPE_ID_LOCAL_RELOC = 0,
    BTF_TYPE_ID_REMOTE_RELOC,
 
    MAX_BTF_TYPE_ID_FLAG,
  };
 
  enum PreserveTypeInfo : uint32_t {
    PRESERVE_TYPE_INFO_EXISTENCE = 0,
    PRESERVE_TYPE_INFO_SIZE,
    PRESERVE_TYPE_INFO_MATCH,
 
    MAX_PRESERVE_TYPE_INFO_FLAG,
  };
 
  enum PreserveEnumValue : uint32_t {
    PRESERVE_ENUM_VALUE_EXISTENCE = 0,
    PRESERVE_ENUM_VALUE,
 
    MAX_PRESERVE_ENUM_VALUE_FLAG,
  };
 
  /// The attribute attached to globals representing a field access
  static constexpr StringRef AmaAttr = "btf_ama";
  /// The attribute attached to globals representing a type id
  static constexpr StringRef TypeIdAttr = "btf_type_id";
 
  /// llvm.bpf.passthrough builtin seq number
  static uint32_t SeqNum;
 
  /// Insert a bpf passthrough builtin function.
  static Instruction *insertPassThrough(Module *M, BasicBlock *BB,
                                        Instruction *Input,
                                        Instruction *Before);
  static void removeArrayAccessCall(CallInst *Call);
  static void removeStructAccessCall(CallInst *Call);
  static void removeUnionAccessCall(CallInst *Call);
};
 
} // namespace llvm
 
#endif