llvm-project

1
//===- MapFile.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 -Map option. It shows lists in order and
10
// hierarchically the output sections, input sections, input files and
11
// symbol:
12
//
13
//       Addr      Off   Size    Out     In      Symbol
14
//          - 00000015     10    .text
15
//          - 0000000e     10            test.o:(.text)
16
//          - 00000000      5                    local
17
//          - 00000000      5                    f(int)
18
//
19
//===----------------------------------------------------------------------===//
20

21
#include "MapFile.h"
22
#include "InputElement.h"
23
#include "InputFiles.h"
24
#include "OutputSections.h"
25
#include "OutputSegment.h"
26
#include "SymbolTable.h"
27
#include "Symbols.h"
28
#include "SyntheticSections.h"
29
#include "lld/Common/Strings.h"
30
#include "llvm/ADT/MapVector.h"
31
#include "llvm/Support/Parallel.h"
32
#include "llvm/Support/raw_ostream.h"
33

34
using namespace llvm;
35
using namespace llvm::object;
36
using namespace lld;
37
using namespace lld::wasm;
38

39
using SymbolMapTy = DenseMap<const InputChunk *, SmallVector<Symbol *, 4>>;
40

41
// Print out the first three columns of a line.
42
static void writeHeader(raw_ostream &os, int64_t vma, uint64_t lma,
43
                        uint64_t size) {
44
  // Not all entries in the map has a virtual memory address (e.g. functions)
45
  if (vma == -1)
46
    os << format("       - %8llx %8llx ", lma, size);
47
  else
48
    os << format("%8llx %8llx %8llx ", vma, lma, size);
49
}
50

51
// Returns a list of all symbols that we want to print out.
52
static std::vector<Symbol *> getSymbols() {
53
  std::vector<Symbol *> v;
54
  for (InputFile *file : ctx.objectFiles)
55
    for (Symbol *b : file->getSymbols())
56
      if (auto *dr = dyn_cast<Symbol>(b))
57
        if ((!isa<SectionSymbol>(dr)) && dr->isLive() &&
58
            (dr->getFile() == file))
59
          v.push_back(dr);
60
  return v;
61
}
62

63
// Returns a map from sections to their symbols.
64
static SymbolMapTy getSectionSyms(ArrayRef<Symbol *> syms) {
65
  SymbolMapTy ret;
66
  for (Symbol *dr : syms)
67
    ret[dr->getChunk()].push_back(dr);
68
  return ret;
69
}
70

71
// Construct a map from symbols to their stringified representations.
72
// Demangling symbols (which is what toString() does) is slow, so
73
// we do that in batch using parallel-for.
74
static DenseMap<Symbol *, std::string>
75
getSymbolStrings(ArrayRef<Symbol *> syms) {
76
  std::vector<std::string> str(syms.size());
77
  parallelFor(0, syms.size(), [&](size_t i) {
78
    raw_string_ostream os(str[i]);
79
    auto *chunk = syms[i]->getChunk();
80
    if (chunk == nullptr)
81
      return;
82
    uint64_t fileOffset = chunk->outputSec != nullptr
83
                              ? chunk->outputSec->getOffset() + chunk->outSecOff
84
                              : 0;
85
    uint64_t vma = -1;
86
    uint64_t size = 0;
87
    if (auto *DD = dyn_cast<DefinedData>(syms[i])) {
88
      vma = DD->getVA();
89
      size = DD->getSize();
90
      fileOffset += DD->value;
91
    }
92
    if (auto *DF = dyn_cast<DefinedFunction>(syms[i])) {
93
      size = DF->function->getSize();
94
    }
95
    writeHeader(os, vma, fileOffset, size);
96
    os.indent(16) << toString(*syms[i]);
97
  });
98

99
  DenseMap<Symbol *, std::string> ret;
100
  for (size_t i = 0, e = syms.size(); i < e; ++i)
101
    ret[syms[i]] = std::move(str[i]);
102
  return ret;
103
}
104

105
void lld::wasm::writeMapFile(ArrayRef<OutputSection *> outputSections) {
106
  if (config->mapFile.empty())
107
    return;
108

109
  // Open a map file for writing.
110
  std::error_code ec;
111
  raw_fd_ostream os(config->mapFile, ec, sys::fs::OF_None);
112
  if (ec) {
113
    error("cannot open " + config->mapFile + ": " + ec.message());
114
    return;
115
  }
116

117
  // Collect symbol info that we want to print out.
118
  std::vector<Symbol *> syms = getSymbols();
119
  SymbolMapTy sectionSyms = getSectionSyms(syms);
120
  DenseMap<Symbol *, std::string> symStr = getSymbolStrings(syms);
121

122
  // Print out the header line.
123
  os << "    Addr      Off     Size Out     In      Symbol\n";
124

125
  for (OutputSection *osec : outputSections) {
126
    writeHeader(os, -1, osec->getOffset(), osec->getSize());
127
    os << toString(*osec) << '\n';
128
    if (auto *code = dyn_cast<CodeSection>(osec)) {
129
      for (auto *chunk : code->functions) {
130
        writeHeader(os, -1, chunk->outputSec->getOffset() + chunk->outSecOff,
131
                    chunk->getSize());
132
        os.indent(8) << toString(chunk) << '\n';
133
        for (Symbol *sym : sectionSyms[chunk])
134
          os << symStr[sym] << '\n';
135
      }
136
    } else if (auto *data = dyn_cast<DataSection>(osec)) {
137
      for (auto *oseg : data->segments) {
138
        writeHeader(os, oseg->startVA, data->getOffset() + oseg->sectionOffset,
139
                    oseg->size);
140
        os << oseg->name << '\n';
141
        for (auto *chunk : oseg->inputSegments) {
142
          uint64_t offset =
143
              chunk->outputSec != nullptr
144
                  ? chunk->outputSec->getOffset() + chunk->outSecOff
145
                  : 0;
146
          writeHeader(os, chunk->getVA(), offset, chunk->getSize());
147
          os.indent(8) << toString(chunk) << '\n';
148
          for (Symbol *sym : sectionSyms[chunk])
149
            os << symStr[sym] << '\n';
150
        }
151
      }
152
    } else if (auto *globals = dyn_cast<GlobalSection>(osec)) {
153
      for (auto *global : globals->inputGlobals) {
154
        writeHeader(os, global->getAssignedIndex(), 0, 0);
155
        os.indent(8) << global->getName() << '\n';
156
      }
157
    }
158
    // TODO: other section/symbol types
159
  }
160
}
161