llvm/llvm/include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h

//===- DWARFAcceleratorTable.h ----------------------------------*- 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_DEBUGINFO_DWARF_DWARFACCELERATORTABLE_H
#define LLVM_DEBUGINFO_DWARF_DWARFACCELERATORTABLE_H

#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include <cstdint>
#include <utility>

namespace llvm {

class raw_ostream;
class ScopedPrinter;

/// The accelerator tables are designed to allow efficient random access
/// (using a symbol name as a key) into debug info by providing an index of the
/// debug info DIEs. This class implements the common functionality of Apple and
/// DWARF 5 accelerator tables.
/// TODO: Generalize the rest of the AppleAcceleratorTable interface and move it
/// to this class.
class DWARFAcceleratorTable { … };

/// This implements the Apple accelerator table format, a precursor of the
/// DWARF 5 accelerator table format.
class AppleAcceleratorTable : public DWARFAcceleratorTable { … };

/// .debug_names section consists of one or more units. Each unit starts with a
/// header, which is followed by a list of compilation units, local and foreign
/// type units.
///
/// These may be followed by an (optional) hash lookup table, which consists of
/// an array of buckets and hashes similar to the apple tables above. The only
/// difference is that the hashes array is 1-based, and consequently an empty
/// bucket is denoted by 0 and not UINT32_MAX.
///
/// Next is the name table, which consists of an array of names and array of
/// entry offsets. This is different from the apple tables, which store names
/// next to the actual entries.
///
/// The structure of the entries is described by an abbreviations table, which
/// comes after the name table. Unlike the apple tables, which have a uniform
/// entry structure described in the header, each .debug_names entry may have
/// different index attributes (DW_IDX_???) attached to it.
///
/// The last segment consists of a list of entries, which is a 0-terminated list
/// referenced by the name table and interpreted with the help of the
/// abbreviation table.
class DWARFDebugNames : public DWARFAcceleratorTable { … };

/// Calculates the starting offsets for various sections within the
/// .debug_names section.
namespace dwarf {
DWARFDebugNames::DWARFDebugNamesOffsets
findDebugNamesOffsets(uint64_t EndOfHeaderOffset,
                      const DWARFDebugNames::Header &Hdr);
}

/// If `Name` is the name of a templated function that includes template
/// parameters, returns a substring of `Name` containing no template
/// parameters.
/// E.g.: StripTemplateParameters("foo<int>") = "foo".
std::optional<StringRef> StripTemplateParameters(StringRef Name);

struct ObjCSelectorNames { … };

/// If `Name` is the AT_name of a DIE which refers to an Objective-C selector,
/// returns an instance of ObjCSelectorNames. The Selector and ClassName fields
/// are guaranteed to be non-empty in the result.
std::optional<ObjCSelectorNames> getObjCNamesIfSelector(StringRef Name);

} // end namespace llvm

#endif // LLVM_DEBUGINFO_DWARF_DWARFACCELERATORTABLE_H