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llvm-mirror/unittests/FuzzMutate/StrategiesTest.cpp
Florian Hahn 5b8c530938 [FuzzMutate] Add mutator to modify instruction flags.
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
2021-01-23 19:05:20 +00:00

244 lines
6.9 KiB
C++

//===- InjectorIRStrategyTest.cpp - Tests for injector strategy -----------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringRef.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/AsmParser/SlotMapping.h"
#include "llvm/FuzzMutate/IRMutator.h"
#include "llvm/FuzzMutate/Operations.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
static constexpr int Seed = 5;
namespace {
std::unique_ptr<IRMutator> createInjectorMutator() {
std::vector<TypeGetter> Types{
Type::getInt1Ty, Type::getInt8Ty, Type::getInt16Ty, Type::getInt32Ty,
Type::getInt64Ty, Type::getFloatTy, Type::getDoubleTy};
std::vector<std::unique_ptr<IRMutationStrategy>> Strategies;
Strategies.push_back(
std::make_unique<InjectorIRStrategy>(
InjectorIRStrategy::getDefaultOps()));
return std::make_unique<IRMutator>(std::move(Types), std::move(Strategies));
}
std::unique_ptr<IRMutator> createDeleterMutator() {
std::vector<TypeGetter> Types{
Type::getInt1Ty, Type::getInt8Ty, Type::getInt16Ty, Type::getInt32Ty,
Type::getInt64Ty, Type::getFloatTy, Type::getDoubleTy};
std::vector<std::unique_ptr<IRMutationStrategy>> Strategies;
Strategies.push_back(std::make_unique<InstDeleterIRStrategy>());
return std::make_unique<IRMutator>(std::move(Types), std::move(Strategies));
}
std::unique_ptr<IRMutator> createInstModifierMutator() {
std::vector<TypeGetter> Types{
Type::getInt1Ty, Type::getInt8Ty, Type::getInt16Ty, Type::getInt32Ty,
Type::getInt64Ty, Type::getFloatTy, Type::getDoubleTy};
std::vector<std::unique_ptr<IRMutationStrategy>> Strategies;
Strategies.push_back(std::make_unique<InstModificationIRStrategy>());
return std::make_unique<IRMutator>(std::move(Types), std::move(Strategies));
}
std::unique_ptr<Module> parseAssembly(
const char *Assembly, LLVMContext &Context) {
SMDiagnostic Error;
std::unique_ptr<Module> M = parseAssemblyString(Assembly, Error, Context);
std::string ErrMsg;
raw_string_ostream OS(ErrMsg);
Error.print("", OS);
assert(M && !verifyModule(*M, &errs()));
return M;
}
void IterateOnSource(StringRef Source, IRMutator &Mutator) {
LLVMContext Ctx;
for (int i = 0; i < 10; ++i) {
auto M = parseAssembly(Source.data(), Ctx);
ASSERT_TRUE(M && !verifyModule(*M, &errs()));
Mutator.mutateModule(*M, Seed, Source.size(), Source.size() + 100);
EXPECT_TRUE(!verifyModule(*M, &errs()));
}
}
TEST(InjectorIRStrategyTest, EmptyModule) {
// Test that we can inject into empty module
LLVMContext Ctx;
auto M = std::make_unique<Module>("M", Ctx);
ASSERT_TRUE(M && !verifyModule(*M, &errs()));
auto Mutator = createInjectorMutator();
ASSERT_TRUE(Mutator);
Mutator->mutateModule(*M, Seed, 1, 1);
EXPECT_TRUE(!verifyModule(*M, &errs()));
}
TEST(InstDeleterIRStrategyTest, EmptyFunction) {
// Test that we don't crash even if we can't remove from one of the functions.
StringRef Source = ""
"define <8 x i32> @func1() {\n"
"ret <8 x i32> undef\n"
"}\n"
"\n"
"define i32 @func2() {\n"
"%A9 = alloca i32\n"
"%L6 = load i32, i32* %A9\n"
"ret i32 %L6\n"
"}\n";
auto Mutator = createDeleterMutator();
ASSERT_TRUE(Mutator);
IterateOnSource(Source, *Mutator);
}
TEST(InstDeleterIRStrategyTest, PhiNodes) {
// Test that inst deleter works correctly with the phi nodes.
LLVMContext Ctx;
StringRef Source = "\n\
define i32 @earlyreturncrash(i32 %x) {\n\
entry:\n\
switch i32 %x, label %sw.epilog [\n\
i32 1, label %sw.bb1\n\
]\n\
\n\
sw.bb1:\n\
br label %sw.epilog\n\
\n\
sw.epilog:\n\
%a.0 = phi i32 [ 7, %entry ], [ 9, %sw.bb1 ]\n\
%b.0 = phi i32 [ 10, %entry ], [ 4, %sw.bb1 ]\n\
ret i32 %a.0\n\
}";
auto Mutator = createDeleterMutator();
ASSERT_TRUE(Mutator);
IterateOnSource(Source, *Mutator);
}
static void checkModifyNoUnsignedAndNoSignedWrap(StringRef Opc) {
LLVMContext Ctx;
std::string Source = std::string("\n\
define i32 @test(i32 %x) {\n\
%a = ") + Opc.str() +
std::string(" i32 %x, 10\n\
ret i32 %a\n\
}");
auto Mutator = createInstModifierMutator();
ASSERT_TRUE(Mutator);
auto M = parseAssembly(Source.data(), Ctx);
auto &F = *M->begin();
auto *AddI = &*F.begin()->begin();
ASSERT_TRUE(M && !verifyModule(*M, &errs()));
bool FoundNUW = false;
bool FoundNSW = false;
for (int i = 0; i < 100; ++i) {
Mutator->mutateModule(*M, Seed + i, Source.size(), Source.size() + 100);
EXPECT_TRUE(!verifyModule(*M, &errs()));
FoundNUW |= AddI->hasNoUnsignedWrap();
FoundNSW |= AddI->hasNoSignedWrap();
}
// The mutator should have added nuw and nsw during some mutations.
EXPECT_TRUE(FoundNUW);
EXPECT_TRUE(FoundNSW);
}
TEST(InstModificationIRStrategyTest, Add) {
checkModifyNoUnsignedAndNoSignedWrap("add");
}
TEST(InstModificationIRStrategyTest, Sub) {
checkModifyNoUnsignedAndNoSignedWrap("sub");
}
TEST(InstModificationIRStrategyTest, Mul) {
checkModifyNoUnsignedAndNoSignedWrap("mul");
}
TEST(InstModificationIRStrategyTest, Shl) {
checkModifyNoUnsignedAndNoSignedWrap("shl");
}
TEST(InstModificationIRStrategyTest, ICmp) {
LLVMContext Ctx;
StringRef Source = "\n\
define i1 @test(i32 %x) {\n\
%a = icmp eq i32 %x, 10\n\
ret i1 %a\n\
}";
auto Mutator = createInstModifierMutator();
ASSERT_TRUE(Mutator);
auto M = parseAssembly(Source.data(), Ctx);
auto &F = *M->begin();
CmpInst *CI = cast<CmpInst>(&*F.begin()->begin());
ASSERT_TRUE(M && !verifyModule(*M, &errs()));
bool FoundNE = false;
for (int i = 0; i < 100; ++i) {
Mutator->mutateModule(*M, Seed + i, Source.size(), Source.size() + 100);
EXPECT_TRUE(!verifyModule(*M, &errs()));
FoundNE |= CI->getPredicate() == CmpInst::ICMP_NE;
}
EXPECT_TRUE(FoundNE);
}
TEST(InstModificationIRStrategyTest, GEP) {
LLVMContext Ctx;
StringRef Source = "\n\
define i32* @test(i32* %ptr) {\n\
%gep = getelementptr i32, i32* %ptr, i32 10\n\
ret i32* %gep\n\
}";
auto Mutator = createInstModifierMutator();
ASSERT_TRUE(Mutator);
auto M = parseAssembly(Source.data(), Ctx);
auto &F = *M->begin();
GetElementPtrInst *GEP = cast<GetElementPtrInst>(&*F.begin()->begin());
ASSERT_TRUE(M && !verifyModule(*M, &errs()));
bool FoundInbounds = false;
for (int i = 0; i < 100; ++i) {
Mutator->mutateModule(*M, Seed + i, Source.size(), Source.size() + 100);
EXPECT_TRUE(!verifyModule(*M, &errs()));
FoundInbounds |= GEP->isInBounds();
}
EXPECT_TRUE(FoundInbounds);
}
}