llvm/lld/ELF/MapFile.cpp

//===- MapFile.cpp --------------------------------------------------------===//
//
// 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 -Map option. It shows lists in order and
// hierarchically the output sections, input sections, input files and
// symbol:
//
//   Address  Size     Align Out     In      Symbol
//   00201000 00000015     4 .text
//   00201000 0000000e     4         test.o:(.text)
//   0020100e 00000000     0                 local
//   00201005 00000000     0                 f(int)
//
//===----------------------------------------------------------------------===//

#include "MapFile.h"
#include "InputFiles.h"
#include "LinkerScript.h"
#include "OutputSections.h"
#include "Symbols.h"
#include "SyntheticSections.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Parallel.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;
usingnamespacellvm::object;
usingnamespacelld;
usingnamespacelld::elf;

SymbolMapTy;

static constexpr char indent8[] = …;          // 8 spaces
static constexpr char indent16[] = …; // 16 spaces

// Print out the first three columns of a line.
static void writeHeader(Ctx &ctx, raw_ostream &os, uint64_t vma, uint64_t lma,
                        uint64_t size, uint64_t align) { … }

// Returns a list of all symbols that we want to print out.
static std::vector<Defined *> getSymbols(Ctx &ctx) { … }

// Returns a map from sections to their symbols.
static SymbolMapTy getSectionSyms(ArrayRef<Defined *> syms) { … }

// Construct a map from symbols to their stringified representations.
// Demangling symbols (which is what toString() does) is slow, so
// we do that in batch using parallel-for.
static DenseMap<Symbol *, std::string>
getSymbolStrings(Ctx &ctx, ArrayRef<Defined *> syms) { … }

// Print .eh_frame contents. Since the section consists of EhSectionPieces,
// we need a specialized printer for that section.
//
// .eh_frame tend to contain a lot of section pieces that are contiguous
// both in input file and output file. Such pieces are squashed before
// being displayed to make output compact.
static void printEhFrame(Ctx &ctx, raw_ostream &os, const EhFrameSection *sec) { … }

static void writeMapFile(Ctx &ctx, raw_fd_ostream &os) { … }

// Output a cross reference table to stdout. This is for --cref.
//
// For each global symbol, we print out a file that defines the symbol
// followed by files that uses that symbol. Here is an example.
//
//     strlen     /lib/x86_64-linux-gnu/libc.so.6
//                tools/lld/tools/lld/CMakeFiles/lld.dir/lld.cpp.o
//                lib/libLLVMSupport.a(PrettyStackTrace.cpp.o)
//
// In this case, strlen is defined by libc.so.6 and used by other two
// files.
static void writeCref(Ctx &ctx, raw_fd_ostream &os) { … }

void elf::writeMapAndCref(Ctx &ctx) { … }