include/llvm/FuzzMutate/RandomIRBuilder.h

   1 //===- RandomIRBuilder.h - Utils for randomly mutation IR -------*- C++ -*-===//
   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 // Provides the Mutator class, which is used to mutate IR for fuzzing.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_FUZZMUTATE_RANDOMIRBUILDER_H
  14 #define LLVM_FUZZMUTATE_RANDOMIRBUILDER_H
  15
  16 #include "llvm/ADT/SmallPtrSet.h"
  17 #include "llvm/FuzzMutate/IRMutator.h"
  18 #include "llvm/FuzzMutate/Random.h"
  19 #include <random>
  20
  21 namespace llvm {
  22
  23 using RandomEngine = std::mt19937;
  24
  25 struct RandomIRBuilder {
  26   RandomEngine Rand;
  27   SmallVector<Type *, 16> KnownTypes;
  28
  29   RandomIRBuilder(int Seed, ArrayRef<Type *> AllowedTypes)
  30       : Rand(Seed), KnownTypes(AllowedTypes.begin(), AllowedTypes.end()) {}
  31
  32   // TODO: Try to make this a bit less of a random mishmash of functions.
  33
  34   /// Find a "source" for some operation, which will be used in one of the
  35   /// operation's operands. This either selects an instruction in \c Insts or
  36   /// returns some new arbitrary Value.
  37   Value *findOrCreateSource(BasicBlock &BB, ArrayRef<Instruction *> Insts);
  38   /// Find a "source" for some operation, which will be used in one of the
  39   /// operation's operands. This either selects an instruction in \c Insts that
  40   /// matches \c Pred, or returns some new Value that matches \c Pred. The
  41   /// values in \c Srcs should be source operands that have already been
  42   /// selected.
  43   Value *findOrCreateSource(BasicBlock &BB, ArrayRef<Instruction *> Insts,
  44                             ArrayRef<Value *> Srcs, fuzzerop::SourcePred Pred);
  45   /// Create some Value suitable as a source for some operation.
  46   Value *newSource(BasicBlock &BB, ArrayRef<Instruction *> Insts,
  47                    ArrayRef<Value *> Srcs, fuzzerop::SourcePred Pred);
  48   /// Find a viable user for \c V in \c Insts, which should all be contained in
  49   /// \c BB. This may also create some new instruction in \c BB and use that.
  50   void connectToSink(BasicBlock &BB, ArrayRef<Instruction *> Insts, Value *V);
  51   /// Create a user for \c V in \c BB.
  52   void newSink(BasicBlock &BB, ArrayRef<Instruction *> Insts, Value *V);
  53   Value *findPointer(BasicBlock &BB, ArrayRef<Instruction *> Insts,
  54                      ArrayRef<Value *> Srcs, fuzzerop::SourcePred Pred);
  55   Type *chooseType(LLVMContext &Context, ArrayRef<Value *> Srcs,
  56                    fuzzerop::SourcePred Pred);
  57 };
  58
  59 } // end llvm namespace
  60
  61 #endif // LLVM_FUZZMUTATE_RANDOMIRBUILDER_H