llvm/tools/vfabi-demangle-fuzzer/vfabi-demangler-fuzzer.cpp

   1 //===-- vfabi-demangler-fuzzer.cpp - Fuzzer VFABI using lib/Fuzzer   ------===//
   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 // Build tool to fuzz the demangler for the vector function ABI names.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/AsmParser/Parser.h"
  14 #include "llvm/IR/Module.h"
  15 #include "llvm/IR/VFABIDemangler.h"
  16 #include "llvm/Support/SourceMgr.h"
  17
  18 using namespace llvm;
  19
  20 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  21   LLVMContext Ctx;
  22   SMDiagnostic Err;
  23   const std::unique_ptr<Module> M =
  24       parseAssemblyString("declare i32 @foo(i32 )\n", Err, Ctx);
  25   const StringRef MangledName((const char *)Data, Size);
  26   // Make sure that whatever symbol the demangler is operating on is
  27   // present in the module (the signature is not important). This is
  28   // because `tryDemangleForVFABI` fails if the function is not
  29   // present. We need to make sure we can even invoke
  30   // `getOrInsertFunction` because such method asserts on strings with
  31   // zeroes.
  32   // TODO: What is this actually testing? That we don't crash?
  33   if (!MangledName.empty() && MangledName.find_first_of(0) == StringRef::npos) {
  34     FunctionType *FTy =
  35         FunctionType::get(Type::getVoidTy(M->getContext()), false);
  36     const auto Info = VFABI::tryDemangleForVFABI(MangledName, FTy);
  37
  38     // Do not optimize away the return value. Inspired by
  39     // https://github.com/google/benchmark/blob/main/include/benchmark/benchmark.h#L307-L345
  40     asm volatile("" : : "r,m"(Info) : "memory");
  41   }
  42
  43   return 0;
  44 }