1 files changed, 90 insertions, 0 deletions
diff --git a/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp b/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
new file mode 100644
index 00000000000..69efd6f38b5
--- /dev/null
+++ b/compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
@@ -0,0 +1,90 @@
+//===- FuzzerDataFlowTrace.cpp - DataFlowTrace                ---*- C++ -* ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// fuzzer::DataFlowTrace
+//===----------------------------------------------------------------------===//
+
+#include "FuzzerDataFlowTrace.h"
+#include "FuzzerIO.h"
+
+#include <cstdlib>
+#include <fstream>
+#include <string>
+#include <vector>
+
+namespace fuzzer {
+
+void DataFlowTrace::Init(const std::string &DirPath,
+                         const std::string &FocusFunction) {
+  if (DirPath.empty()) return;
+  const char *kFunctionsTxt = "functions.txt";
+  Printf("INFO: DataFlowTrace: reading from '%s'\n", DirPath.c_str());
+  Vector<SizedFile> Files;
+  GetSizedFilesFromDir(DirPath, &Files);
+  std::string L;
+
+  // Read functions.txt
+  std::ifstream IF(DirPlusFile(DirPath, kFunctionsTxt));
+  size_t FocusFuncIdx = SIZE_MAX;
+  size_t NumFunctions = 0;
+  while (std::getline(IF, L, '\n')) {
+    NumFunctions++;
+    if (FocusFunction == L)
+      FocusFuncIdx = NumFunctions - 1;
+  }
+  if (!NumFunctions || FocusFuncIdx == SIZE_MAX || Files.size() <= 1)
+    return;
+  // Read traces.
+  size_t NumTraceFiles = 0;
+  size_t NumTracesWithFocusFunction = 0;
+  for (auto &SF : Files) {
+    auto Name = Basename(SF.File);
+    if (Name == kFunctionsTxt) continue;
+    auto ParseError = [&](const char *Err) {
+      Printf("DataFlowTrace: parse error: %s\n  File: %s\n  Line: %s\n", Err,
+             Name.c_str(), L.c_str());
+    };
+    NumTraceFiles++;
+    // Printf("=== %s\n", Name.c_str());
+    std::ifstream IF(SF.File);
+    while (std::getline(IF, L, '\n')) {
+      size_t SpacePos = L.find(' ');
+      if (SpacePos == std::string::npos)
+        return ParseError("no space in the trace line");
+      if (L.empty() || L[0] != 'F')
+        return ParseError("the trace line doesn't start with 'F'");
+      size_t N = std::atol(L.c_str() + 1);
+      if (N >= NumFunctions)
+        return ParseError("N is greater than the number of functions");
+      if (N == FocusFuncIdx) {
+        NumTracesWithFocusFunction++;
+        const char *Beg = L.c_str() + SpacePos + 1;
+        const char *End = L.c_str() + L.size();
+        assert(Beg < End);
+        size_t Len = End - Beg;
+        Vector<bool> V(Len);
+        for (size_t I = 0; I < Len; I++) {
+          if (Beg[I] != '0' && Beg[I] != '1')
+            ParseError("the trace should contain only 0 or 1");
+          V[I] = Beg[I] == '1';
+        }
+        // Print just a few small traces.
+        if (NumTracesWithFocusFunction <= 3 && Len <= 16)
+          Printf("%s => |%s|\n", Name.c_str(), L.c_str() + SpacePos + 1);
+        break;  // No need to parse the following lines.
+      }
+    }
+  }
+  assert(NumTraceFiles == Files.size() - 1);
+  Printf("INFO: DataFlowTrace: %zd trace files, %zd functions, "
+         "%zd traces with focus function\n",
+         NumTraceFiles, NumFunctions, NumTracesWithFocusFunction);
+}
+
+}  // namespace fuzzer
+