clang-tools-extra/pseudo/fuzzer/Fuzzer.cpp

   1 //===-- Fuzzer.cpp - Fuzz the pseudoparser --------------------------------===//
   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 #include "clang-pseudo/DirectiveTree.h"
  10 #include "clang-pseudo/Forest.h"
  11 #include "clang-pseudo/GLR.h"
  12 #include "clang-pseudo/Token.h"
  13 #include "clang-pseudo/cli/CLI.h"
  14 #include "clang-pseudo/grammar/Grammar.h"
  15 #include "clang-pseudo/grammar/LRTable.h"
  16 #include "clang/Basic/LangOptions.h"
  17 #include "llvm/ADT/StringRef.h"
  18 #include "llvm/Support/MemoryBuffer.h"
  19 #include "llvm/Support/raw_ostream.h"
  20 #include <algorithm>
  21
  22 namespace clang {
  23 namespace pseudo {
  24 namespace {
  25
  26 class Fuzzer {
  27   clang::LangOptions LangOpts = clang::pseudo::genericLangOpts();
  28   bool Print;
  29
  30 public:
  31   Fuzzer(bool Print) : Print(Print) {}
  32
  33   void operator()(llvm::StringRef Code) {
  34     std::string CodeStr = Code.str(); // Must be null-terminated.
  35     auto RawStream = lex(CodeStr, LangOpts);
  36     auto DirectiveStructure = DirectiveTree::parse(RawStream);
  37     clang::pseudo::chooseConditionalBranches(DirectiveStructure, RawStream);
  38     // FIXME: strip preprocessor directives
  39     auto ParseableStream =
  40         clang::pseudo::stripComments(cook(RawStream, LangOpts));
  41
  42     clang::pseudo::ForestArena Arena;
  43     clang::pseudo::GSS GSS;
  44     const Language &Lang = getLanguageFromFlags();
  45     auto &Root =
  46         glrParse(clang::pseudo::ParseParams{ParseableStream, Arena, GSS},
  47                  *Lang.G.findNonterminal("translation-unit"), Lang);
  48     if (Print)
  49       llvm::outs() << Root.dumpRecursive(Lang.G);
  50   }
  51 };
  52
  53 Fuzzer *Fuzz = nullptr;
  54
  55 } // namespace
  56 } // namespace pseudo
  57 } // namespace clang
  58
  59 extern "C" {
  60
  61 // Set up the fuzzer from command line flags:
  62 //  -print                     - used for testing the fuzzer
  63 int LLVMFuzzerInitialize(int *Argc, char ***Argv) {
  64   bool PrintForest = false;
  65   auto ConsumeArg = [&](llvm::StringRef Arg) -> bool {
  66     if (Arg == "-print") {
  67       PrintForest = true;
  68       return true;
  69     }
  70     return false;
  71   };
  72   *Argc = std::remove_if(*Argv + 1, *Argv + *Argc, ConsumeArg) - *Argv;
  73
  74   clang::pseudo::Fuzz = new clang::pseudo::Fuzzer(PrintForest);
  75   return 0;
  76 }
  77
  78 int LLVMFuzzerTestOneInput(uint8_t *Data, size_t Size) {
  79   (*clang::pseudo::Fuzz)(llvm::StringRef(reinterpret_cast<char *>(Data), Size));
  80   return 0;
  81 }
  82 }