mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 02:33:06 +01:00
5b8c530938
This patch adds a new InstModificationIRStrategy to mutate flags/options for instructions. For example, it may add or remove nuw/nsw flags from add, mul, sub, shl instructions or change the predicate for icmp instructions. Subtle changes such as those mentioned above should lead to a more interesting range of inputs. The presence or absence of overflow flags can expose subtle bugs, for example. Reviewed By: bogner Differential Revision: https://reviews.llvm.org/D94905
119 lines
4.0 KiB
C++
119 lines
4.0 KiB
C++
//===-- IRMutator.h - Mutation engine for fuzzing IR ------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Provides the IRMutator class, which drives mutations on IR based on a
|
|
// configurable set of strategies. Some common strategies are also included
|
|
// here.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_FUZZMUTATE_IRMUTATOR_H
|
|
#define LLVM_FUZZMUTATE_IRMUTATOR_H
|
|
|
|
#include "llvm/ADT/Optional.h"
|
|
#include "llvm/FuzzMutate/OpDescriptor.h"
|
|
#include "llvm/Support/ErrorHandling.h"
|
|
|
|
namespace llvm {
|
|
class BasicBlock;
|
|
class Function;
|
|
class Instruction;
|
|
class Module;
|
|
|
|
struct RandomIRBuilder;
|
|
|
|
/// Base class for describing how to mutate a module. mutation functions for
|
|
/// each IR unit forward to the contained unit.
|
|
class IRMutationStrategy {
|
|
public:
|
|
virtual ~IRMutationStrategy() = default;
|
|
|
|
/// Provide a weight to bias towards choosing this strategy for a mutation.
|
|
///
|
|
/// The value of the weight is arbitrary, but a good default is "the number of
|
|
/// distinct ways in which this strategy can mutate a unit". This can also be
|
|
/// used to prefer strategies that shrink the overall size of the result when
|
|
/// we start getting close to \c MaxSize.
|
|
virtual uint64_t getWeight(size_t CurrentSize, size_t MaxSize,
|
|
uint64_t CurrentWeight) = 0;
|
|
|
|
/// @{
|
|
/// Mutators for each IR unit. By default these forward to a contained
|
|
/// instance of the next smaller unit.
|
|
virtual void mutate(Module &M, RandomIRBuilder &IB);
|
|
virtual void mutate(Function &F, RandomIRBuilder &IB);
|
|
virtual void mutate(BasicBlock &BB, RandomIRBuilder &IB);
|
|
virtual void mutate(Instruction &I, RandomIRBuilder &IB) {
|
|
llvm_unreachable("Strategy does not implement any mutators");
|
|
}
|
|
/// @}
|
|
};
|
|
|
|
using TypeGetter = std::function<Type *(LLVMContext &)>;
|
|
|
|
/// Entry point for configuring and running IR mutations.
|
|
class IRMutator {
|
|
std::vector<TypeGetter> AllowedTypes;
|
|
std::vector<std::unique_ptr<IRMutationStrategy>> Strategies;
|
|
|
|
public:
|
|
IRMutator(std::vector<TypeGetter> &&AllowedTypes,
|
|
std::vector<std::unique_ptr<IRMutationStrategy>> &&Strategies)
|
|
: AllowedTypes(std::move(AllowedTypes)),
|
|
Strategies(std::move(Strategies)) {}
|
|
|
|
void mutateModule(Module &M, int Seed, size_t CurSize, size_t MaxSize);
|
|
};
|
|
|
|
/// Strategy that injects operations into the function.
|
|
class InjectorIRStrategy : public IRMutationStrategy {
|
|
std::vector<fuzzerop::OpDescriptor> Operations;
|
|
|
|
Optional<fuzzerop::OpDescriptor> chooseOperation(Value *Src,
|
|
RandomIRBuilder &IB);
|
|
|
|
public:
|
|
InjectorIRStrategy(std::vector<fuzzerop::OpDescriptor> &&Operations)
|
|
: Operations(std::move(Operations)) {}
|
|
static std::vector<fuzzerop::OpDescriptor> getDefaultOps();
|
|
|
|
uint64_t getWeight(size_t CurrentSize, size_t MaxSize,
|
|
uint64_t CurrentWeight) override {
|
|
return Operations.size();
|
|
}
|
|
|
|
using IRMutationStrategy::mutate;
|
|
void mutate(Function &F, RandomIRBuilder &IB) override;
|
|
void mutate(BasicBlock &BB, RandomIRBuilder &IB) override;
|
|
};
|
|
|
|
class InstDeleterIRStrategy : public IRMutationStrategy {
|
|
public:
|
|
uint64_t getWeight(size_t CurrentSize, size_t MaxSize,
|
|
uint64_t CurrentWeight) override;
|
|
|
|
using IRMutationStrategy::mutate;
|
|
void mutate(Function &F, RandomIRBuilder &IB) override;
|
|
void mutate(Instruction &Inst, RandomIRBuilder &IB) override;
|
|
};
|
|
|
|
class InstModificationIRStrategy : public IRMutationStrategy {
|
|
public:
|
|
uint64_t getWeight(size_t CurrentSize, size_t MaxSize,
|
|
uint64_t CurrentWeight) override {
|
|
return 4;
|
|
}
|
|
|
|
using IRMutationStrategy::mutate;
|
|
void mutate(Instruction &Inst, RandomIRBuilder &IB) override;
|
|
};
|
|
|
|
} // end llvm namespace
|
|
|
|
#endif // LLVM_FUZZMUTATE_IRMUTATOR_H
|