llvm-for-llvmta/unittests/Analysis/CFGTest.cpp

508 lines
14 KiB
C++

//===- CFGTest.cpp - CFG tests --------------------------------------------===//
//
// 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/Analysis/CFG.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Module.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
// This fixture assists in running the isPotentiallyReachable utility four ways
// and ensuring it produces the correct answer each time.
class IsPotentiallyReachableTest : public testing::Test {
protected:
void ParseAssembly(const char *Assembly) {
SMDiagnostic Error;
M = parseAssemblyString(Assembly, Error, Context);
std::string errMsg;
raw_string_ostream os(errMsg);
Error.print("", os);
// A failure here means that the test itself is buggy.
if (!M)
report_fatal_error(os.str().c_str());
Function *F = M->getFunction("test");
if (F == nullptr)
report_fatal_error("Test must have a function named @test");
A = B = nullptr;
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
if (I->hasName()) {
if (I->getName() == "A")
A = &*I;
else if (I->getName() == "B")
B = &*I;
}
}
if (A == nullptr)
report_fatal_error("@test must have an instruction %A");
if (B == nullptr)
report_fatal_error("@test must have an instruction %B");
assert(ExclusionSet.empty());
for (auto I = F->begin(), E = F->end(); I != E; ++I) {
if (I->hasName() && I->getName().startswith("excluded"))
ExclusionSet.insert(&*I);
}
}
void ExpectPath(bool ExpectedResult) {
static char ID;
class IsPotentiallyReachableTestPass : public FunctionPass {
public:
IsPotentiallyReachableTestPass(bool ExpectedResult, Instruction *A,
Instruction *B,
SmallPtrSet<BasicBlock *, 4> ExclusionSet)
: FunctionPass(ID), ExpectedResult(ExpectedResult), A(A), B(B),
ExclusionSet(ExclusionSet) {}
static int initialize() {
PassInfo *PI = new PassInfo("isPotentiallyReachable testing pass", "",
&ID, nullptr, true, true);
PassRegistry::getPassRegistry()->registerPass(*PI, false);
initializeLoopInfoWrapperPassPass(*PassRegistry::getPassRegistry());
initializeDominatorTreeWrapperPassPass(
*PassRegistry::getPassRegistry());
return 0;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
AU.addRequired<LoopInfoWrapperPass>();
AU.addRequired<DominatorTreeWrapperPass>();
}
bool runOnFunction(Function &F) override {
if (!F.hasName() || F.getName() != "test")
return false;
LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
DominatorTree *DT =
&getAnalysis<DominatorTreeWrapperPass>().getDomTree();
EXPECT_EQ(isPotentiallyReachable(A, B, &ExclusionSet, nullptr, nullptr),
ExpectedResult);
EXPECT_EQ(isPotentiallyReachable(A, B, &ExclusionSet, DT, nullptr),
ExpectedResult);
EXPECT_EQ(isPotentiallyReachable(A, B, &ExclusionSet, nullptr, LI),
ExpectedResult);
EXPECT_EQ(isPotentiallyReachable(A, B, &ExclusionSet, DT, LI),
ExpectedResult);
return false;
}
bool ExpectedResult;
Instruction *A, *B;
SmallPtrSet<BasicBlock *, 4> ExclusionSet;
};
static int initialize = IsPotentiallyReachableTestPass::initialize();
(void)initialize;
IsPotentiallyReachableTestPass *P =
new IsPotentiallyReachableTestPass(ExpectedResult, A, B, ExclusionSet);
legacy::PassManager PM;
PM.add(P);
PM.run(*M);
}
LLVMContext Context;
std::unique_ptr<Module> M;
Instruction *A, *B;
SmallPtrSet<BasicBlock *, 4> ExclusionSet;
};
}
TEST_F(IsPotentiallyReachableTest, SameBlockNoPath) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" bitcast i8 undef to i8\n"
" %B = bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"}\n");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, SameBlockPath) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" %A = bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}\n");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, SameBlockNoLoop) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" br label %middle\n"
"middle:\n"
" %B = bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" bitcast i8 undef to i8\n"
" %A = bitcast i8 undef to i8\n"
" br label %nextblock\n"
"nextblock:\n"
" ret void\n"
"}\n");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, StraightNoPath) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" %B = bitcast i8 undef to i8\n"
" br label %exit\n"
"exit:\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, StraightPath) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" %A = bitcast i8 undef to i8\n"
" br label %exit\n"
"exit:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, DestUnreachable) {
ParseAssembly(
"define void @test() {\n"
"entry:\n"
" br label %midblock\n"
"midblock:\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"unreachable:\n"
" %B = bitcast i8 undef to i8\n"
" br label %midblock\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, BranchToReturn) {
ParseAssembly(
"define void @test(i1 %x) {\n"
"entry:\n"
" %A = bitcast i8 undef to i8\n"
" br i1 %x, label %block1, label %block2\n"
"block1:\n"
" ret void\n"
"block2:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, SimpleLoop1) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %loop\n"
"loop:\n"
" %B = bitcast i8 undef to i8\n"
" %A = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %loop, label %exit\n"
"exit:\n"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, SimpleLoop2) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" %B = bitcast i8 undef to i8\n"
" br label %loop\n"
"loop:\n"
" %A = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %loop, label %exit\n"
"exit:\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, SimpleLoop3) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %loop\n"
"loop:\n"
" %B = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %loop, label %exit\n"
"exit:\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, OneLoopAfterTheOther1) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %loop1\n"
"loop1:\n"
" %A = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %loop1, label %loop1exit\n"
"loop1exit:\n"
" br label %loop2\n"
"loop2:\n"
" %B = bitcast i8 undef to i8\n"
" %y = call i1 @switch()\n"
" br i1 %x, label %loop2, label %loop2exit\n"
"loop2exit:"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, OneLoopAfterTheOther2) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %loop1\n"
"loop1:\n"
" %B = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %loop1, label %loop1exit\n"
"loop1exit:\n"
" br label %loop2\n"
"loop2:\n"
" %A = bitcast i8 undef to i8\n"
" %y = call i1 @switch()\n"
" br i1 %x, label %loop2, label %loop2exit\n"
"loop2exit:"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, OneLoopAfterTheOtherInsideAThirdLoop) {
ParseAssembly(
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %outerloop3\n"
"outerloop3:\n"
" br label %innerloop1\n"
"innerloop1:\n"
" %B = bitcast i8 undef to i8\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %innerloop1, label %innerloop1exit\n"
"innerloop1exit:\n"
" br label %innerloop2\n"
"innerloop2:\n"
" %A = bitcast i8 undef to i8\n"
" %y = call i1 @switch()\n"
" br i1 %x, label %innerloop2, label %innerloop2exit\n"
"innerloop2exit:"
" ;; In outer loop3 now.\n"
" %z = call i1 @switch()\n"
" br i1 %z, label %outerloop3, label %exit\n"
"exit:\n"
" ret void\n"
"}");
ExpectPath(true);
}
static const char *BranchInsideLoopIR =
"declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" br label %loop\n"
"loop:\n"
" %x = call i1 @switch()\n"
" br i1 %x, label %nextloopblock, label %exit\n"
"nextloopblock:\n"
" %y = call i1 @switch()\n"
" br i1 %y, label %left, label %right\n"
"left:\n"
" %A = bitcast i8 undef to i8\n"
" br label %loop\n"
"right:\n"
" %B = bitcast i8 undef to i8\n"
" br label %loop\n"
"exit:\n"
" ret void\n"
"}";
TEST_F(IsPotentiallyReachableTest, BranchInsideLoop) {
ParseAssembly(BranchInsideLoopIR);
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, ModifyTest) {
ParseAssembly(BranchInsideLoopIR);
succ_iterator S = succ_begin(&*++M->getFunction("test")->begin());
BasicBlock *OldBB = S[0];
S[0] = S[1];
ExpectPath(false);
S[0] = OldBB;
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, UnreachableFromEntryTest) {
ParseAssembly("define void @test() {\n"
"entry:\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"not.reachable:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, UnreachableBlocksTest1) {
ParseAssembly("define void @test() {\n"
"entry:\n"
" ret void\n"
"not.reachable.1:\n"
" %A = bitcast i8 undef to i8\n"
" br label %not.reachable.2\n"
"not.reachable.2:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, UnreachableBlocksTest2) {
ParseAssembly("define void @test() {\n"
"entry:\n"
" ret void\n"
"not.reachable.1:\n"
" %B = bitcast i8 undef to i8\n"
" br label %not.reachable.2\n"
"not.reachable.2:\n"
" %A = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, SimpleExclusionTest) {
ParseAssembly("define void @test() {\n"
"entry:\n"
" %A = bitcast i8 undef to i8\n"
" br label %excluded\n"
"excluded:\n"
" br label %exit\n"
"exit:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, DiamondExcludedTest) {
ParseAssembly("declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" %x = call i1 @switch()\n"
" %A = bitcast i8 undef to i8\n"
" br i1 %x, label %excluded.1, label %excluded.2\n"
"excluded.1:\n"
" br label %exit\n"
"excluded.2:\n"
" br label %exit\n"
"exit:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(false);
}
TEST_F(IsPotentiallyReachableTest, DiamondOneSideExcludedTest) {
ParseAssembly("declare i1 @switch()\n"
"\n"
"define void @test() {\n"
"entry:\n"
" %x = call i1 @switch()\n"
" %A = bitcast i8 undef to i8\n"
" br i1 %x, label %excluded, label %diamond\n"
"excluded:\n"
" br label %exit\n"
"diamond:\n"
" br label %exit\n"
"exit:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(true);
}
TEST_F(IsPotentiallyReachableTest, UnreachableToReachable) {
ParseAssembly("define void @test() {\n"
"entry:\n"
" br label %exit\n"
"unreachableblock:\n"
" %A = bitcast i8 undef to i8\n"
" br label %exit\n"
"exit:\n"
" %B = bitcast i8 undef to i8\n"
" ret void\n"
"}");
ExpectPath(true);
}