llvm/unittests/Analysis/TBAATest.cpp

   1 //===--- TBAATest.cpp - Mixed TBAA unit tests -----------------------------===//
   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 #include "llvm/IR/Constants.h"
  10 #include "llvm/IR/Instructions.h"
  11 #include "llvm/IR/LLVMContext.h"
  12 #include "llvm/IR/MDBuilder.h"
  13 #include "llvm/IR/Module.h"
  14 #include "llvm/IR/Verifier.h"
  15 #include "llvm/Support/CommandLine.h"
  16 #include "gtest/gtest.h"
  17
  18 namespace llvm {
  19 namespace {
  20
  21 class TBAATest : public testing::Test {
  22 protected:
  23   TBAATest() : M("TBAATest", C), MD(C) {}
  24
  25   LLVMContext C;
  26   Module M;
  27   MDBuilder MD;
  28 };
  29
  30 static StoreInst *getFunctionWithSingleStore(Module *M, StringRef Name) {
  31   auto &C = M->getContext();
  32   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), {});
  33   auto *F = Function::Create(FTy, Function::ExternalLinkage, Name, M);
  34   auto *BB = BasicBlock::Create(C, "entry", F);
  35   auto *IntType = Type::getInt32Ty(C);
  36   auto *PtrType = PointerType::get(C, 0);
  37   auto *SI = new StoreInst(ConstantInt::get(IntType, 42),
  38                            ConstantPointerNull::get(PtrType), BB);
  39   ReturnInst::Create(C, nullptr, BB);
  40
  41   return SI;
  42 }
  43
  44 TEST_F(TBAATest, checkVerifierBehaviorForOldTBAA) {
  45   auto *SI = getFunctionWithSingleStore(&M, "f1");
  46   auto *F = SI->getFunction();
  47
  48   // C++ unit test case to avoid going through the auto upgrade logic.
  49   auto *RootMD = MD.createTBAARoot("Simple C/C++ TBAA");
  50   auto *MD1 = MD.createTBAANode("omnipotent char", RootMD);
  51   auto *MD2 = MD.createTBAANode("int", MD1);
  52   SI->setMetadata(LLVMContext::MD_tbaa, MD2);
  53
  54   SmallVector<char, 0> ErrorMsg;
  55   raw_svector_ostream Outs(ErrorMsg);
  56
  57   StringRef ExpectedFailureMsg(
  58       "Old-style TBAA is no longer allowed, use struct-path TBAA instead");
  59
  60   EXPECT_TRUE(verifyFunction(*F, &Outs));
  61   EXPECT_TRUE(StringRef(ErrorMsg.begin(), ErrorMsg.size())
  62                   .starts_with(ExpectedFailureMsg));
  63 }
  64
  65 TEST_F(TBAATest, checkTBAAMerging) {
  66   auto *SI = getFunctionWithSingleStore(&M, "f2");
  67   auto *F = SI->getFunction();
  68
  69   auto *RootMD = MD.createTBAARoot("tbaa-root");
  70   auto *MD1 = MD.createTBAANode("scalar-a", RootMD);
  71   auto *StructTag1 = MD.createTBAAStructTagNode(MD1, MD1, 0);
  72   auto *MD2 = MD.createTBAANode("scalar-b", RootMD);
  73   auto *StructTag2 = MD.createTBAAStructTagNode(MD2, MD2, 0);
  74
  75   auto *GenericMD = MDNode::getMostGenericTBAA(StructTag1, StructTag2);
  76
  77   EXPECT_EQ(GenericMD, nullptr);
  78
  79   // Despite GenericMD being nullptr, we expect the setMetadata call to be well
  80   // defined and produce a well-formed function.
  81   SI->setMetadata(LLVMContext::MD_tbaa, GenericMD);
  82
  83   EXPECT_TRUE(!verifyFunction(*F));
  84 }
  85
  86 } // end anonymous namspace
  87 } // end llvm namespace