Rearrange Dom unittest to accommodate multiple tests

[anemet]

Summary

I've taken the approach from the LoopInfo test:

• Rather than running in the pass manager just build the analyses manually
• Split out the common parts (makeLLVMModule, runWithDomTree) into helpers

[sanjoy]

lgtm

unittests/IR/DominatorTreeTest.cpp

32

I'd write this as DominatorTreeBase<BasicBlock> PDT(/*isPostDom*/true)

39

I'd either assert or ASSERT that the module was successfully parsed. (This part's optional) I'd also prefer StringRef as an argument, and also in the declaration of ModuleString.

unittests/IR/DominatorTreeTest.cpp

 //===- llvm/unittests/IR/DominatorTreeTest.cpp - Constants 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/PostDominators.h"
 #include "llvm/AsmParser/Parser.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/SourceMgr.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
 
-namespace llvm {
-void initializeDPassPass(PassRegistry &);
+/// Build the dominator tree for the function and run the Test.
+static void
+runWithDomTree(Module &M, StringRef FuncName,
+               function_ref<void(Function &F, DominatorTree *DT,
+                                 DominatorTreeBase<BasicBlock> *PDT)>
+                   Test) {
+  auto *F = M.getFunction(FuncName);
+  ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
+  // Compute the dominator tree for the function.
+  DominatorTree DT(*F);
+  DominatorTreeBase<BasicBlock> PDT(true);
+  PDT.recalculate(*F);
+  Test(*F, &DT, &PDT);
+}
 
-namespace {
-struct DPass : public FunctionPass {
-  static char ID;
-  bool runOnFunction(Function &F) override {
-    DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-    PostDominatorTree *PDT =
-        &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree();
+static std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
+                                              const char *ModuleStr) {
+  SMDiagnostic Err;
+  return parseAssemblyString(ModuleStr, Err, Context);
+}
+
+TEST(DominatorTree, Unreachable) {
+  const char *ModuleString =
+      "declare i32 @g()\n"
+      "define void @f(i32 %x) personality i32 ()* @g {\n"
+      "bb0:\n"
+      "  %y1 = add i32 %x, 1\n"
+      "  %y2 = add i32 %x, 1\n"
+      "  %y3 = invoke i32 @g() to label %bb1 unwind label %bb2\n"
+      "bb1:\n"
+      "  %y4 = add i32 %x, 1\n"
+      "  br label %bb4\n"
+      "bb2:\n"
+      "  %y5 = landingpad i32\n"
+      "          cleanup\n"
+      "  br label %bb4\n"
+      "bb3:\n"
+      "  %y6 = add i32 %x, 1\n"
+      "  %y7 = add i32 %x, 1\n"
+      "  ret void\n"
+      "bb4:\n"
+      "  %y8 = phi i32 [0, %bb2], [%y4, %bb1]\n"
+      "  %y9 = phi i32 [0, %bb2], [%y4, %bb1]\n"
+      "  ret void\n"
+      "}\n";
+
+  // Parse the module.
+  LLVMContext Context;
+  std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
+
+  runWithDomTree(
+      *M, "f",
+      [&](Function &F, DominatorTree *DT, DominatorTreeBase<BasicBlock> *PDT) {
         Function::iterator FI = F.begin();
 
         BasicBlock *BB0 = &*FI++;
         BasicBlock::iterator BBI = BB0->begin();
         Instruction *Y1 = &*BBI++;
         Instruction *Y2 = &*BBI++;
         Instruction *Y3 = &*BBI++;
 
         BasicBlock *BB1 = &*FI++;
         BBI = BB1->begin();
         Instruction *Y4 = &*BBI++;
 
         BasicBlock *BB2 = &*FI++;
         BBI = BB2->begin();
         Instruction *Y5 = &*BBI++;
 
         BasicBlock *BB3 = &*FI++;
         BBI = BB3->begin();
         Instruction *Y6 = &*BBI++;
         Instruction *Y7 = &*BBI++;
 
         BasicBlock *BB4 = &*FI++;
         BBI = BB4->begin();
         Instruction *Y8 = &*BBI++;
         Instruction *Y9 = &*BBI++;
 
         // Reachability
         EXPECT_TRUE(DT->isReachableFromEntry(BB0));
         EXPECT_TRUE(DT->isReachableFromEntry(BB1));
         EXPECT_TRUE(DT->isReachableFromEntry(BB2));
         EXPECT_FALSE(DT->isReachableFromEntry(BB3));
         EXPECT_TRUE(DT->isReachableFromEntry(BB4));
 
         // BB dominance
         EXPECT_TRUE(DT->dominates(BB0, BB0));
         EXPECT_TRUE(DT->dominates(BB0, BB1));
         EXPECT_TRUE(DT->dominates(BB0, BB2));
         EXPECT_TRUE(DT->dominates(BB0, BB3));
         EXPECT_TRUE(DT->dominates(BB0, BB4));
 
         EXPECT_FALSE(DT->dominates(BB1, BB0));
         EXPECT_TRUE(DT->dominates(BB1, BB1));
         EXPECT_FALSE(DT->dominates(BB1, BB2));
         EXPECT_TRUE(DT->dominates(BB1, BB3));
         EXPECT_FALSE(DT->dominates(BB1, BB4));
 
         EXPECT_FALSE(DT->dominates(BB2, BB0));
         EXPECT_FALSE(DT->dominates(BB2, BB1));
         EXPECT_TRUE(DT->dominates(BB2, BB2));
         EXPECT_TRUE(DT->dominates(BB2, BB3));
         EXPECT_FALSE(DT->dominates(BB2, BB4));
 
         EXPECT_FALSE(DT->dominates(BB3, BB0));
         EXPECT_FALSE(DT->dominates(BB3, BB1));
         EXPECT_FALSE(DT->dominates(BB3, BB2));
         EXPECT_TRUE(DT->dominates(BB3, BB3));
         EXPECT_FALSE(DT->dominates(BB3, BB4));
 
         // BB proper dominance
         EXPECT_FALSE(DT->properlyDominates(BB0, BB0));
         EXPECT_TRUE(DT->properlyDominates(BB0, BB1));
         EXPECT_TRUE(DT->properlyDominates(BB0, BB2));
         EXPECT_TRUE(DT->properlyDominates(BB0, BB3));
 
         EXPECT_FALSE(DT->properlyDominates(BB1, BB0));
         EXPECT_FALSE(DT->properlyDominates(BB1, BB1));
         EXPECT_FALSE(DT->properlyDominates(BB1, BB2));
         EXPECT_TRUE(DT->properlyDominates(BB1, BB3));
 
         EXPECT_FALSE(DT->properlyDominates(BB2, BB0));
         EXPECT_FALSE(DT->properlyDominates(BB2, BB1));
         EXPECT_FALSE(DT->properlyDominates(BB2, BB2));
         EXPECT_TRUE(DT->properlyDominates(BB2, BB3));
 
         EXPECT_FALSE(DT->properlyDominates(BB3, BB0));
         EXPECT_FALSE(DT->properlyDominates(BB3, BB1));
         EXPECT_FALSE(DT->properlyDominates(BB3, BB2));
         EXPECT_FALSE(DT->properlyDominates(BB3, BB3));
 
         // Instruction dominance in the same reachable BB
         EXPECT_FALSE(DT->dominates(Y1, Y1));
         EXPECT_TRUE(DT->dominates(Y1, Y2));
         EXPECT_FALSE(DT->dominates(Y2, Y1));
         EXPECT_FALSE(DT->dominates(Y2, Y2));
 
         // Instruction dominance in the same unreachable BB
         EXPECT_TRUE(DT->dominates(Y6, Y6));
         EXPECT_TRUE(DT->dominates(Y6, Y7));
         EXPECT_TRUE(DT->dominates(Y7, Y6));
         EXPECT_TRUE(DT->dominates(Y7, Y7));
 
         // Invoke
         EXPECT_TRUE(DT->dominates(Y3, Y4));
         EXPECT_FALSE(DT->dominates(Y3, Y5));
 
         // Phi
         EXPECT_TRUE(DT->dominates(Y2, Y9));
         EXPECT_FALSE(DT->dominates(Y3, Y9));
         EXPECT_FALSE(DT->dominates(Y8, Y9));
 
         // Anything dominates unreachable
         EXPECT_TRUE(DT->dominates(Y1, Y6));
         EXPECT_TRUE(DT->dominates(Y3, Y6));
 
         // Unreachable doesn't dominate reachable
         EXPECT_FALSE(DT->dominates(Y6, Y1));
 
         // Instruction, BB dominance
         EXPECT_FALSE(DT->dominates(Y1, BB0));
         EXPECT_TRUE(DT->dominates(Y1, BB1));
         EXPECT_TRUE(DT->dominates(Y1, BB2));
         EXPECT_TRUE(DT->dominates(Y1, BB3));
         EXPECT_TRUE(DT->dominates(Y1, BB4));
 
         EXPECT_FALSE(DT->dominates(Y3, BB0));
         EXPECT_TRUE(DT->dominates(Y3, BB1));
         EXPECT_FALSE(DT->dominates(Y3, BB2));
         EXPECT_TRUE(DT->dominates(Y3, BB3));
         EXPECT_FALSE(DT->dominates(Y3, BB4));
 
         EXPECT_TRUE(DT->dominates(Y6, BB3));
 
         // Post dominance.
         EXPECT_TRUE(PDT->dominates(BB0, BB0));
         EXPECT_FALSE(PDT->dominates(BB1, BB0));
         EXPECT_FALSE(PDT->dominates(BB2, BB0));
         EXPECT_FALSE(PDT->dominates(BB3, BB0));
         EXPECT_TRUE(PDT->dominates(BB4, BB1));
 
         // Dominance descendants.
         SmallVector<BasicBlock *, 8> DominatedBBs, PostDominatedBBs;
 
         DT->getDescendants(BB0, DominatedBBs);
         PDT->getDescendants(BB0, PostDominatedBBs);
         EXPECT_EQ(DominatedBBs.size(), 4UL);
         EXPECT_EQ(PostDominatedBBs.size(), 1UL);
 
         // BB3 is unreachable. It should have no dominators nor postdominators.
         DominatedBBs.clear();
         PostDominatedBBs.clear();
         DT->getDescendants(BB3, DominatedBBs);
         DT->getDescendants(BB3, PostDominatedBBs);
         EXPECT_EQ(DominatedBBs.size(), 0UL);
         EXPECT_EQ(PostDominatedBBs.size(), 0UL);
 
         // Check DFS Numbers before
         EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
         EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 7UL);
         EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
         EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 2UL);
         EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 5UL);
         EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 6UL);
         EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 3UL);
         EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 4UL);
 
         // Reattach block 3 to block 1 and recalculate
         BB1->getTerminator()->eraseFromParent();
         BranchInst::Create(BB4, BB3, ConstantInt::getTrue(F.getContext()), BB1);
         DT->recalculate(F);
 
         // Check DFS Numbers after
         EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
         EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 9UL);
         EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
         EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 4UL);
         EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 7UL);
         EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 8UL);
         EXPECT_EQ(DT->getNode(BB3)->getDFSNumIn(), 2UL);
         EXPECT_EQ(DT->getNode(BB3)->getDFSNumOut(), 3UL);
         EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 5UL);
         EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 6UL);
 
         // Change root node
         DT->verifyDomTree();
         BasicBlock *NewEntry =
             BasicBlock::Create(F.getContext(), "new_entry", &F, BB0);
         BranchInst::Create(BB0, NewEntry);
         EXPECT_EQ(F.begin()->getName(), NewEntry->getName());
         EXPECT_TRUE(&F.getEntryBlock() == NewEntry);
         DT->setNewRoot(NewEntry);
         DT->verifyDomTree();
-
-    return false;
-  }
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<DominatorTreeWrapperPass>();
-    AU.addRequired<PostDominatorTreeWrapperPass>();
-  }
-  DPass() : FunctionPass(ID) {
-    initializeDPassPass(*PassRegistry::getPassRegistry());
-  }
-};
-char DPass::ID = 0;
-
-std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context, DPass *P) {
-  const char *ModuleString =
-      "declare i32 @g()\n"
-      "define void @f(i32 %x) personality i32 ()* @g {\n"
-      "bb0:\n"
-      "  %y1 = add i32 %x, 1\n"
-      "  %y2 = add i32 %x, 1\n"
-      "  %y3 = invoke i32 @g() to label %bb1 unwind label %bb2\n"
-      "bb1:\n"
-      "  %y4 = add i32 %x, 1\n"
-      "  br label %bb4\n"
-      "bb2:\n"
-      "  %y5 = landingpad i32\n"
-      "          cleanup\n"
-      "  br label %bb4\n"
-      "bb3:\n"
-      "  %y6 = add i32 %x, 1\n"
-      "  %y7 = add i32 %x, 1\n"
-      "  ret void\n"
-      "bb4:\n"
-      "  %y8 = phi i32 [0, %bb2], [%y4, %bb1]\n"
-      "  %y9 = phi i32 [0, %bb2], [%y4, %bb1]\n"
-      "  ret void\n"
-      "}\n";
-  SMDiagnostic Err;
-  return parseAssemblyString(ModuleString, Err, Context);
-}
-
-TEST(DominatorTree, Unreachable) {
-  DPass *P = new DPass();
-  LLVMContext Context;
-  std::unique_ptr<Module> M = makeLLVMModule(Context, P);
-  legacy::PassManager Passes;
-  Passes.add(P);
-  Passes.run(*M);
-}
-} // namespace
-} // namespace llvm
-
-INITIALIZE_PASS_BEGIN(DPass, "dpass", "dpass", false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
-INITIALIZE_PASS_END(DPass, "dpass", "dpass", false, false)
+      });