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 "Symbols.h"
27#include "SyntheticSections.h"
28#include "llvm/Support/Parallel.h"
29#include "llvm/Support/raw_ostream.h"
30
31using namespace llvm;
32using namespace llvm::object;
33using namespace lld;
34using namespace lld::wasm;
35
36using SymbolMapTy = DenseMap<const InputChunk *, SmallVector<Symbol *, 4>>;
37
38// Print out the first three columns of a line.
39static void writeHeader(raw_ostream &os, int64_t vma, uint64_t lma,
40 uint64_t size) {
41 // Not all entries in the map has a virtual memory address (e.g. functions)
42 if (vma == -1)
43 os << format(Fmt: " - %8llx %8llx ", Vals: lma, Vals: size);
44 else
45 os << format(Fmt: "%8llx %8llx %8llx ", Vals: vma, Vals: lma, Vals: size);
46}
47
48// Returns a list of all symbols that we want to print out.
49static std::vector<Symbol *> getSymbols() {
50 std::vector<Symbol *> v;
51 for (InputFile *file : ctx.objectFiles)
52 for (Symbol *b : file->getSymbols())
53 if (auto *dr = dyn_cast<Symbol>(Val: b))
54 if ((!isa<SectionSymbol>(Val: dr)) && dr->isLive() &&
55 (dr->getFile() == file))
56 v.push_back(x: dr);
57 return v;
58}
59
60// Returns a map from sections to their symbols.
61static SymbolMapTy getSectionSyms(ArrayRef<Symbol *> syms) {
62 SymbolMapTy ret;
63 for (Symbol *dr : syms)
64 ret[dr->getChunk()].push_back(Elt: dr);
65 return ret;
66}
67
68// Construct a map from symbols to their stringified representations.
69// Demangling symbols (which is what toString() does) is slow, so
70// we do that in batch using parallel-for.
71static DenseMap<Symbol *, std::string>
72getSymbolStrings(ArrayRef<Symbol *> syms) {
73 std::vector<std::string> str(syms.size());
74 parallelFor(Begin: 0, End: syms.size(), Fn: [&](size_t i) {
75 raw_string_ostream os(str[i]);
76 auto *chunk = syms[i]->getChunk();
77 if (chunk == nullptr)
78 return;
79 uint64_t fileOffset = chunk->outputSec != nullptr
80 ? chunk->outputSec->getOffset() + chunk->outSecOff
81 : 0;
82 uint64_t vma = -1;
83 uint64_t size = 0;
84 if (auto *DD = dyn_cast<DefinedData>(Val: syms[i])) {
85 vma = DD->getVA();
86 size = DD->getSize();
87 fileOffset += DD->value;
88 }
89 if (auto *DF = dyn_cast<DefinedFunction>(Val: syms[i])) {
90 size = DF->function->getSize();
91 }
92 writeHeader(os, vma, lma: fileOffset, size);
93 os.indent(NumSpaces: 16) << toString(sym: *syms[i]);
94 });
95
96 DenseMap<Symbol *, std::string> ret;
97 for (size_t i = 0, e = syms.size(); i < e; ++i)
98 ret[syms[i]] = std::move(str[i]);
99 return ret;
100}
101
102void lld::wasm::writeMapFile(ArrayRef<OutputSection *> outputSections) {
103 if (ctx.arg.mapFile.empty())
104 return;
105
106 // Open a map file for writing.
107 std::error_code ec;
108 raw_fd_ostream os(ctx.arg.mapFile, ec, sys::fs::OF_None);
109 if (ec) {
110 error(msg: "cannot open " + ctx.arg.mapFile + ": " + ec.message());
111 return;
112 }
113
114 // Collect symbol info that we want to print out.
115 std::vector<Symbol *> syms = getSymbols();
116 SymbolMapTy sectionSyms = getSectionSyms(syms);
117 DenseMap<Symbol *, std::string> symStr = getSymbolStrings(syms);
118
119 // Print out the header line.
120 os << " Addr Off Size Out In Symbol\n";
121
122 for (OutputSection *osec : outputSections) {
123 writeHeader(os, vma: -1, lma: osec->getOffset(), size: osec->getSize());
124 os << toString(section: *osec) << '\n';
125 if (auto *code = dyn_cast<CodeSection>(Val: osec)) {
126 for (auto *chunk : code->functions) {
127 writeHeader(os, vma: -1, lma: chunk->outputSec->getOffset() + chunk->outSecOff,
128 size: chunk->getSize());
129 os.indent(NumSpaces: 8) << toString(chunk) << '\n';
130 for (Symbol *sym : sectionSyms[chunk])
131 os << symStr[sym] << '\n';
132 }
133 } else if (auto *data = dyn_cast<DataSection>(Val: osec)) {
134 for (auto *oseg : data->segments) {
135 writeHeader(os, vma: oseg->startVA, lma: data->getOffset() + oseg->sectionOffset,
136 size: oseg->size);
137 os << oseg->name << '\n';
138 for (auto *chunk : oseg->inputSegments) {
139 uint64_t offset =
140 chunk->outputSec != nullptr
141 ? chunk->outputSec->getOffset() + chunk->outSecOff
142 : 0;
143 writeHeader(os, vma: chunk->getVA(), lma: offset, size: chunk->getSize());
144 os.indent(NumSpaces: 8) << toString(chunk) << '\n';
145 for (Symbol *sym : sectionSyms[chunk])
146 os << symStr[sym] << '\n';
147 }
148 }
149 } else if (auto *globals = dyn_cast<GlobalSection>(Val: osec)) {
150 for (auto *global : globals->inputGlobals) {
151 writeHeader(os, vma: global->getAssignedIndex(), lma: 0, size: 0);
152 os.indent(NumSpaces: 8) << global->getName() << '\n';
153 }
154 }
155 // TODO: other section/symbol types
156 }
157}
158