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
21namespace llvm {
22
23using RandomEngine = std::mt19937;
24
25struct 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
62