llvm/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp

//===-- llvm/CodeGen/DIEHash.cpp - Dwarf Hashing Framework ----------------===//
//
// 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 contains support for DWARF4 hashing of DIEs.
//
//===----------------------------------------------------------------------===//

#include "DIEHash.h"
#include "ByteStreamer.h"
#include "DwarfCompileUnit.h"
#include "DwarfDebug.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;

#define DEBUG_TYPE …

/// Grabs the string in whichever attribute is passed in and returns
/// a reference to it.
static StringRef getDIEStringAttr(const DIE &Die, uint16_t Attr) { … }

/// Adds the string in \p Str to the hash. This also hashes
/// a trailing NULL with the string.
void DIEHash::addString(StringRef Str) { … }

// FIXME: The LEB128 routines are copied and only slightly modified out of
// LEB128.h.

/// Adds the unsigned in \p Value to the hash encoded as a ULEB128.
void DIEHash::addULEB128(uint64_t Value) { … }

void DIEHash::addSLEB128(int64_t Value) { … }

/// Including \p Parent adds the context of Parent to the hash..
void DIEHash::addParentContext(const DIE &Parent) { … }

// Collect all of the attributes for a particular DIE in single structure.
void DIEHash::collectAttributes(const DIE &Die, DIEAttrs &Attrs) { … }

void DIEHash::hashShallowTypeReference(dwarf::Attribute Attribute,
                                       const DIE &Entry, StringRef Name) { … }

void DIEHash::hashRepeatedTypeReference(dwarf::Attribute Attribute,
                                        unsigned DieNumber) { … }

void DIEHash::hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,
                           const DIE &Entry) { … }

void DIEHash::hashRawTypeReference(const DIE &Entry) { … }

// Hash all of the values in a block like set of values. This assumes that
// all of the data is going to be added as integers.
void DIEHash::hashBlockData(const DIE::const_value_range &Values) { … }

// Hash the contents of a loclistptr class.
void DIEHash::hashLocList(const DIELocList &LocList) { … }

// Hash an individual attribute \param Attr based on the type of attribute and
// the form.
void DIEHash::hashAttribute(const DIEValue &Value, dwarf::Tag Tag) { … }

// Go through the attributes from \param Attrs in the order specified in 7.27.4
// and hash them.
void DIEHash::hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag) { … }

// Add all of the attributes for \param Die to the hash.
void DIEHash::addAttributes(const DIE &Die) { … }

void DIEHash::hashNestedType(const DIE &Die, StringRef Name) { … }

// Compute the hash of a DIE. This is based on the type signature computation
// given in section 7.27 of the DWARF4 standard. It is the md5 hash of a
// flattened description of the DIE.
void DIEHash::computeHash(const DIE &Die) { … }

/// This is based on the type signature computation given in section 7.27 of the
/// DWARF4 standard. It is an md5 hash of the flattened description of the DIE
/// with the inclusion of the full CU and all top level CU entities.
// TODO: Initialize the type chain at 0 instead of 1 for CU signatures.
uint64_t DIEHash::computeCUSignature(StringRef DWOName, const DIE &Die) { … }

/// This is based on the type signature computation given in section 7.27 of the
/// DWARF4 standard. It is an md5 hash of the flattened description of the DIE
/// with the inclusion of additional forms not specifically called out in the
/// standard.
uint64_t DIEHash::computeTypeSignature(const DIE &Die) { … }