1//===- LLDMapFile.cpp -----------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the /lldmap option. It shows lists in order and
10// hierarchically the output sections, input sections, input files and
11// symbol:
12//
13//   Address  Size     Align Out     File    Symbol
14//   00201000 00000015     4 .text
15//   00201000 0000000e     4         test.o:(.text)
16//   0020100e 00000000     0                 local
17//   00201005 00000000     0                 f(int)
18//
19//===----------------------------------------------------------------------===//
20
21#include "LLDMapFile.h"
22#include "COFFLinkerContext.h"
23#include "SymbolTable.h"
24#include "Symbols.h"
25#include "Writer.h"
26#include "lld/Common/ErrorHandler.h"
27#include "llvm/Support/Parallel.h"
28#include "llvm/Support/raw_ostream.h"
29
30using namespace llvm;
31using namespace llvm::object;
32using namespace lld;
33using namespace lld::coff;
34
35using SymbolMapTy =
36    DenseMap<const SectionChunk *, SmallVector<DefinedRegular *, 4>>;
37
38static constexpr char indent8[] = "        ";          // 8 spaces
39static constexpr char indent16[] = "                "; // 16 spaces
40
41// Print out the first three columns of a line.
42static void writeHeader(raw_ostream &os, uint64_t addr, uint64_t size,
43                        uint64_t align) {
44  os << format("%08llx %08llx %5lld ", addr, size, align);
45}
46
47// Returns a list of all symbols that we want to print out.
48static std::vector<DefinedRegular *> getSymbols(const COFFLinkerContext &ctx) {
49  std::vector<DefinedRegular *> v;
50  for (ObjFile *file : ctx.objFileInstances)
51    for (Symbol *b : file->getSymbols())
52      if (auto *sym = dyn_cast_or_null<DefinedRegular>(b))
53        if (sym && !sym->getCOFFSymbol().isSectionDefinition())
54          v.push_back(sym);
55  return v;
56}
57
58// Returns a map from sections to their symbols.
59static SymbolMapTy getSectionSyms(ArrayRef<DefinedRegular *> syms) {
60  SymbolMapTy ret;
61  for (DefinedRegular *s : syms)
62    ret[s->getChunk()].push_back(s);
63
64  // Sort symbols by address.
65  for (auto &it : ret) {
66    SmallVectorImpl<DefinedRegular *> &v = it.second;
67    std::stable_sort(v.begin(), v.end(), [](DefinedRegular *a, DefinedRegular *b) {
68      return a->getRVA() < b->getRVA();
69    });
70  }
71  return ret;
72}
73
74// Construct a map from symbols to their stringified representations.
75static DenseMap<DefinedRegular *, std::string>
76getSymbolStrings(const COFFLinkerContext &ctx,
77                 ArrayRef<DefinedRegular *> syms) {
78  std::vector<std::string> str(syms.size());
79  parallelFor((size_t)0, syms.size(), [&](size_t i) {
80    raw_string_ostream os(str[i]);
81    writeHeader(os, syms[i]->getRVA(), 0, 0);
82    os << indent16 << toString(ctx, *syms[i]);
83  });
84
85  DenseMap<DefinedRegular *, std::string> ret;
86  for (size_t i = 0, e = syms.size(); i < e; ++i)
87    ret[syms[i]] = std::move(str[i]);
88  return ret;
89}
90
91void lld::coff::writeLLDMapFile(const COFFLinkerContext &ctx) {
92  if (ctx.config.lldmapFile.empty())
93    return;
94
95  std::error_code ec;
96  raw_fd_ostream os(ctx.config.lldmapFile, ec, sys::fs::OF_None);
97  if (ec)
98    fatal("cannot open " + ctx.config.lldmapFile + ": " + ec.message());
99
100  // Collect symbol info that we want to print out.
101  std::vector<DefinedRegular *> syms = getSymbols(ctx);
102  SymbolMapTy sectionSyms = getSectionSyms(syms);
103  DenseMap<DefinedRegular *, std::string> symStr = getSymbolStrings(ctx, syms);
104
105  // Print out the header line.
106  os << "Address  Size     Align Out     In      Symbol\n";
107
108  // Print out file contents.
109  for (OutputSection *sec : ctx.outputSections) {
110    writeHeader(os, sec->getRVA(), sec->getVirtualSize(), /*align=*/pageSize);
111    os << sec->name << '\n';
112
113    for (Chunk *c : sec->chunks) {
114      auto *sc = dyn_cast<SectionChunk>(c);
115      if (!sc)
116        continue;
117
118      writeHeader(os, sc->getRVA(), sc->getSize(), sc->getAlignment());
119      os << indent8 << sc->file->getName() << ":(" << sc->getSectionName()
120         << ")\n";
121      for (DefinedRegular *sym : sectionSyms[sc])
122        os << symStr[sym] << '\n';
123    }
124  }
125}
126