Files
clang-p2996/llvm/tools/dsymutil/DwarfLinkerForBinary.h
Augusto Noronha 44a609cd59 [dsymutil] Update vector of section starts with size of current section
Take into account the contributions of the sections from different
object files when calculating the address where relocations should be
applied.

Differential Revision: https://reviews.llvm.org/D122239
2022-03-23 10:15:54 -03:00

244 lines
9.5 KiB
C++

//===- tools/dsymutil/DwarfLinkerForBinary.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_TOOLS_DSYMUTIL_DWARFLINKER_H
#define LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H
#include "BinaryHolder.h"
#include "DebugMap.h"
#include "LinkUtils.h"
#include "MachOUtils.h"
#include "llvm/DWARFLinker/DWARFLinker.h"
#include "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
#include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
#include "llvm/DWARFLinker/DWARFStreamer.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/Remarks/RemarkFormat.h"
#include "llvm/Remarks/RemarkLinker.h"
namespace llvm {
namespace dsymutil {
/// The core of the Dsymutil Dwarf linking logic.
///
/// The link of the dwarf information from the object files will be
/// driven by DWARFLinker. DwarfLinkerForBinary reads DebugMap objects
/// and pass information to the DWARFLinker. DWARFLinker
/// optimizes DWARF taking into account valid relocations.
/// Finally, optimized DWARF is passed to DwarfLinkerForBinary through
/// DWARFEmitter interface.
class DwarfLinkerForBinary {
public:
DwarfLinkerForBinary(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,
LinkOptions Options)
: OutFile(OutFile), BinHolder(BinHolder), Options(std::move(Options)) {}
/// Link the contents of the DebugMap.
bool link(const DebugMap &);
void reportWarning(const Twine &Warning, StringRef Context,
const DWARFDie *DIE = nullptr) const;
/// Flags passed to DwarfLinker::lookForDIEsToKeep
enum TraversalFlags {
TF_Keep = 1 << 0, ///< Mark the traversed DIEs as kept.
TF_InFunctionScope = 1 << 1, ///< Current scope is a function scope.
TF_DependencyWalk = 1 << 2, ///< Walking the dependencies of a kept DIE.
TF_ParentWalk = 1 << 3, ///< Walking up the parents of a kept DIE.
TF_ODR = 1 << 4, ///< Use the ODR while keeping dependents.
TF_SkipPC = 1 << 5, ///< Skip all location attributes.
};
private:
/// Keeps track of relocations.
class AddressManager : public AddressesMap {
struct ValidReloc {
uint64_t Offset;
uint32_t Size;
uint64_t Addend;
const DebugMapObject::DebugMapEntry *Mapping;
ValidReloc(uint64_t Offset, uint32_t Size, uint64_t Addend,
const DebugMapObject::DebugMapEntry *Mapping)
: Offset(Offset), Size(Size), Addend(Addend), Mapping(Mapping) {}
bool operator<(const ValidReloc &RHS) const {
return Offset < RHS.Offset;
}
bool operator<(uint64_t RHS) const { return Offset < RHS; }
};
const DwarfLinkerForBinary &Linker;
/// The valid relocations for the current DebugMapObject.
/// This vector is sorted by relocation offset.
/// {
std::vector<ValidReloc> ValidDebugInfoRelocs;
std::vector<ValidReloc> ValidDebugAddrRelocs;
/// }
RangesTy AddressRanges;
StringRef SrcFileName;
/// Returns list of valid relocations from \p Relocs,
/// between \p StartOffset and \p NextOffset.
///
/// \returns true if any relocation is found.
std::vector<ValidReloc>
getRelocations(const std::vector<ValidReloc> &Relocs, uint64_t StartPos,
uint64_t EndPos);
/// Resolve specified relocation \p Reloc.
///
/// \returns resolved value.
uint64_t relocate(const ValidReloc &Reloc) const;
/// Fill \p Info with address information for the specified \p Reloc.
void fillDieInfo(const ValidReloc &Reloc, CompileUnit::DIEInfo &Info);
/// Print contents of debug map entry for the specified \p Reloc.
void printReloc(const ValidReloc &Reloc);
public:
AddressManager(DwarfLinkerForBinary &Linker, const object::ObjectFile &Obj,
const DebugMapObject &DMO)
: Linker(Linker), SrcFileName(DMO.getObjectFilename()) {
findValidRelocsInDebugSections(Obj, DMO);
// Iterate over the debug map entries and put all the ones that are
// functions (because they have a size) into the Ranges map. This map is
// very similar to the FunctionRanges that are stored in each unit, with 2
// notable differences:
//
// 1. Obviously this one is global, while the other ones are per-unit.
//
// 2. This one contains not only the functions described in the DIE
// tree, but also the ones that are only in the debug map.
//
// The latter information is required to reproduce dsymutil's logic while
// linking line tables. The cases where this information matters look like
// bugs that need to be investigated, but for now we need to reproduce
// dsymutil's behavior.
// FIXME: Once we understood exactly if that information is needed,
// maybe totally remove this (or try to use it to do a real
// -gline-tables-only on Darwin.
for (const auto &Entry : DMO.symbols()) {
const auto &Mapping = Entry.getValue();
if (Mapping.Size && Mapping.ObjectAddress)
AddressRanges[*Mapping.ObjectAddress] = ObjFileAddressRange(
*Mapping.ObjectAddress + Mapping.Size,
int64_t(Mapping.BinaryAddress) - *Mapping.ObjectAddress);
}
}
virtual ~AddressManager() override { clear(); }
virtual bool areRelocationsResolved() const override { return true; }
bool hasValidRelocs() override {
return !ValidDebugInfoRelocs.empty() || !ValidDebugAddrRelocs.empty();
}
/// \defgroup FindValidRelocations Translate debug map into a list
/// of relevant relocations
///
/// @{
bool findValidRelocsInDebugSections(const object::ObjectFile &Obj,
const DebugMapObject &DMO);
bool findValidRelocs(const object::SectionRef &Section,
const object::ObjectFile &Obj,
const DebugMapObject &DMO,
std::vector<ValidReloc> &ValidRelocs);
void findValidRelocsMachO(const object::SectionRef &Section,
const object::MachOObjectFile &Obj,
const DebugMapObject &DMO,
std::vector<ValidReloc> &ValidRelocs);
/// @}
/// Checks that there is a relocation in the \p Relocs array against a
/// debug map entry between \p StartOffset and \p NextOffset.
///
/// \returns true and sets Info.InDebugMap if it is the case.
bool hasValidRelocationAt(const std::vector<ValidReloc> &Relocs,
uint64_t StartOffset, uint64_t EndOffset,
CompileUnit::DIEInfo &Info);
bool hasLiveMemoryLocation(const DWARFDie &DIE,
CompileUnit::DIEInfo &Info) override;
bool hasLiveAddressRange(const DWARFDie &DIE,
CompileUnit::DIEInfo &Info) override;
bool applyValidRelocs(MutableArrayRef<char> Data, uint64_t BaseOffset,
bool IsLittleEndian) override;
llvm::Expected<uint64_t> relocateIndexedAddr(uint64_t StartOffset,
uint64_t EndOffset) override;
RangesTy &getValidAddressRanges() override { return AddressRanges; }
void clear() override {
AddressRanges.clear();
ValidDebugInfoRelocs.clear();
ValidDebugAddrRelocs.clear();
}
};
private:
/// \defgroup Helpers Various helper methods.
///
/// @{
bool createStreamer(const Triple &TheTriple, raw_fd_ostream &OutFile);
/// Attempt to load a debug object from disk.
ErrorOr<const object::ObjectFile &> loadObject(const DebugMapObject &Obj,
const Triple &triple);
ErrorOr<DWARFFile &> loadObject(const DebugMapObject &Obj,
const DebugMap &DebugMap,
remarks::RemarkLinker &RL);
void collectRelocationsToApplyToSwiftReflectionSections(
const object::SectionRef &Section, StringRef &Contents,
const llvm::object::MachOObjectFile *MO,
const std::vector<uint64_t> &SectionToOffsetInDwarf,
const llvm::dsymutil::DebugMapObject *Obj,
std::vector<MachOUtils::DwarfRelocationApplicationInfo>
&RelocationsToApply) const;
void copySwiftReflectionMetadata(
const llvm::dsymutil::DebugMapObject *Obj, DwarfStreamer *Streamer,
std::vector<uint64_t> &SectionToOffsetInDwarf,
std::vector<MachOUtils::DwarfRelocationApplicationInfo>
&RelocationsToApply);
raw_fd_ostream &OutFile;
BinaryHolder &BinHolder;
LinkOptions Options;
std::unique_ptr<DwarfStreamer> Streamer;
std::vector<std::unique_ptr<DWARFFile>> ObjectsForLinking;
std::vector<std::unique_ptr<DWARFContext>> ContextForLinking;
std::vector<std::unique_ptr<AddressManager>> AddressMapForLinking;
std::vector<std::string> EmptyWarnings;
/// A list of all .swiftinterface files referenced by the debug
/// info, mapping Module name to path on disk. The entries need to
/// be uniqued and sorted and there are only few entries expected
/// per compile unit, which is why this is a std::map.
std::map<std::string, std::string> ParseableSwiftInterfaces;
bool ModuleCacheHintDisplayed = false;
bool ArchiveHintDisplayed = false;
};
} // end namespace dsymutil
} // end namespace llvm
#endif // LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H