llvm/unittests/Analysis/TBAATest.cpp
Sanjoy Das 965b15e108 [TBAA] Don't generate invalid TBAA when merging nodes
Summary:
Fix a corner case in `MDNode::getMostGenericTBAA` where we can sometimes
generate invalid TBAA metadata.

Reviewers: chandlerc, hfinkel, mehdi_amini, manmanren

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D26635

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289403 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-11 20:07:25 +00:00

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2.9 KiB
C++

//===--- TBAATest.cpp - Mixed TBAA unit tests -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/AliasAnalysisEvaluator.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/CommandLine.h"
#include "gtest/gtest.h"
namespace llvm {
namespace {
class TBAATest : public testing::Test {
protected:
TBAATest() : M("TBAATest", C), MD(C) {}
LLVMContext C;
Module M;
MDBuilder MD;
};
static StoreInst *getFunctionWithSingleStore(Module *M, StringRef Name) {
auto &C = M->getContext();
FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), {});
auto *F = cast<Function>(M->getOrInsertFunction(Name, FTy));
auto *BB = BasicBlock::Create(C, "entry", F);
auto *IntType = Type::getInt32Ty(C);
auto *PtrType = Type::getInt32PtrTy(C);
auto *SI = new StoreInst(ConstantInt::get(IntType, 42),
ConstantPointerNull::get(PtrType), BB);
ReturnInst::Create(C, nullptr, BB);
return SI;
}
TEST_F(TBAATest, checkVerifierBehaviorForOldTBAA) {
auto *SI = getFunctionWithSingleStore(&M, "f1");
auto *F = SI->getFunction();
// C++ unit test case to avoid going through the auto upgrade logic.
auto *RootMD = MD.createTBAARoot("Simple C/C++ TBAA");
auto *MD1 = MD.createTBAANode("omnipotent char", RootMD);
auto *MD2 = MD.createTBAANode("int", MD1);
SI->setMetadata(LLVMContext::MD_tbaa, MD2);
SmallVector<char, 0> ErrorMsg;
raw_svector_ostream Outs(ErrorMsg);
StringRef ExpectedFailureMsg(
"Old-style TBAA is no longer allowed, use struct-path TBAA instead");
EXPECT_TRUE(verifyFunction(*F, &Outs));
EXPECT_TRUE(StringRef(ErrorMsg.begin(), ErrorMsg.size())
.startswith(ExpectedFailureMsg));
}
TEST_F(TBAATest, checkTBAAMerging) {
auto *SI = getFunctionWithSingleStore(&M, "f2");
auto *F = SI->getFunction();
auto *RootMD = MD.createTBAARoot("tbaa-root");
auto *MD1 = MD.createTBAANode("scalar-a", RootMD);
auto *StructTag1 = MD.createTBAAStructTagNode(MD1, MD1, 0);
auto *MD2 = MD.createTBAANode("scalar-b", RootMD);
auto *StructTag2 = MD.createTBAAStructTagNode(MD2, MD2, 0);
auto *GenericMD = MDNode::getMostGenericTBAA(StructTag1, StructTag2);
EXPECT_EQ(GenericMD, nullptr);
// Despite GenericMD being nullptr, we expect the setMetadata call to be well
// defined and produce a well-formed function.
SI->setMetadata(LLVMContext::MD_tbaa, GenericMD);
EXPECT_TRUE(!verifyFunction(*F));
}
} // end anonymous namspace
} // end llvm namespace