1//===- FuzzerDataFlowTrace.cpp - DataFlowTrace                ---*- C++ -* ===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9// fuzzer::DataFlowTrace
10//===----------------------------------------------------------------------===//
11
12#include "FuzzerDataFlowTrace.h"
13#include "FuzzerIO.h"
14
15#include <cstdlib>
16#include <fstream>
17#include <string>
18#include <vector>
19
20namespace fuzzer {
21
22void DataFlowTrace::Init(const std::string &DirPath,
23                         const std::string &FocusFunction) {
24  if (DirPath.empty()) return;
25  const char *kFunctionsTxt = "functions.txt";
26  Printf("INFO: DataFlowTrace: reading from '%s'\n", DirPath.c_str());
27  Vector<SizedFile> Files;
28  GetSizedFilesFromDir(DirPath, &Files);
29  std::string L;
30
31  // Read functions.txt
32  std::ifstream IF(DirPlusFile(DirPath, kFunctionsTxt));
33  size_t FocusFuncIdx = SIZE_MAX;
34  size_t NumFunctions = 0;
35  while (std::getline(IF, L, '\n')) {
36    NumFunctions++;
37    if (FocusFunction == L)
38      FocusFuncIdx = NumFunctions - 1;
39  }
40  if (!NumFunctions || FocusFuncIdx == SIZE_MAX || Files.size() <= 1)
41    return;
42  // Read traces.
43  size_t NumTraceFiles = 0;
44  size_t NumTracesWithFocusFunction = 0;
45  for (auto &SF : Files) {
46    auto Name = Basename(SF.File);
47    if (Name == kFunctionsTxt) continue;
48    auto ParseError = [&](const char *Err) {
49      Printf("DataFlowTrace: parse error: %s\n  File: %s\n  Line: %s\n", Err,
50             Name.c_str(), L.c_str());
51    };
52    NumTraceFiles++;
53    // Printf("=== %s\n", Name.c_str());
54    std::ifstream IF(SF.File);
55    while (std::getline(IF, L, '\n')) {
56      size_t SpacePos = L.find(' ');
57      if (SpacePos == std::string::npos)
58        return ParseError("no space in the trace line");
59      if (L.empty() || L[0] != 'F')
60        return ParseError("the trace line doesn't start with 'F'");
61      size_t N = std::atol(L.c_str() + 1);
62      if (N >= NumFunctions)
63        return ParseError("N is greater than the number of functions");
64      if (N == FocusFuncIdx) {
65        NumTracesWithFocusFunction++;
66        const char *Beg = L.c_str() + SpacePos + 1;
67        const char *End = L.c_str() + L.size();
68        assert(Beg < End);
69        size_t Len = End - Beg;
70        Vector<uint8_t> V(Len);
71        for (size_t I = 0; I < Len; I++) {
72          if (Beg[I] != '0' && Beg[I] != '1')
73            ParseError("the trace should contain only 0 or 1");
74          V[I] = Beg[I] == '1';
75        }
76        Traces[Name] = V;
77        // Print just a few small traces.
78        if (NumTracesWithFocusFunction <= 3 && Len <= 16)
79          Printf("%s => |%s|\n", Name.c_str(), L.c_str() + SpacePos + 1);
80        break;  // No need to parse the following lines.
81      }
82    }
83  }
84  assert(NumTraceFiles == Files.size() - 1);
85  Printf("INFO: DataFlowTrace: %zd trace files, %zd functions, "
86         "%zd traces with focus function\n",
87         NumTraceFiles, NumFunctions, NumTracesWithFocusFunction);
88}
89
90}  // namespace fuzzer
91
92