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
34using namespace llvm;
35using namespace llvm::object;
36using namespace lld;
37using namespace lld::wasm;
38
39using SymbolMapTy = DenseMap<const InputChunk *, SmallVector<Symbol *, 4>>;
40
41// Print out the first three columns of a line.
42static 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.
52static std::vector<Symbol *> getSymbols() {
53  std::vector<Symbol *> v;
54  for (InputFile *file : symtab->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.
64static 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.
74static DenseMap<Symbol *, std::string>
75getSymbolStrings(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
105void 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