llvm-project/llvm/unittests/Analysis/LazyCallGraphTest.cpp

721 lines
22 KiB
C++

//===- LazyCallGraphTest.cpp - Unit tests for the lazy CG analysis --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LazyCallGraph.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
#include <memory>
using namespace llvm;
namespace {
std::unique_ptr<Module> parseAssembly(const char *Assembly) {
auto M = make_unique<Module>("Module", getGlobalContext());
SMDiagnostic Error;
bool Parsed =
ParseAssemblyString(Assembly, M.get(), Error, M->getContext()) == M.get();
std::string ErrMsg;
raw_string_ostream OS(ErrMsg);
Error.print("", OS);
// A failure here means that the test itself is buggy.
if (!Parsed)
report_fatal_error(OS.str().c_str());
return M;
}
// IR forming a call graph with a diamond of triangle-shaped SCCs:
//
// d1
// / \
// d3--d2
// / \
// b1 c1
// / \ / \
// b3--b2 c3--c2
// \ /
// a1
// / \
// a3--a2
//
// All call edges go up between SCCs, and clockwise around the SCC.
static const char DiamondOfTriangles[] =
"define void @a1() {\n"
"entry:\n"
" call void @a2()\n"
" call void @b2()\n"
" call void @c3()\n"
" ret void\n"
"}\n"
"define void @a2() {\n"
"entry:\n"
" call void @a3()\n"
" ret void\n"
"}\n"
"define void @a3() {\n"
"entry:\n"
" call void @a1()\n"
" ret void\n"
"}\n"
"define void @b1() {\n"
"entry:\n"
" call void @b2()\n"
" call void @d3()\n"
" ret void\n"
"}\n"
"define void @b2() {\n"
"entry:\n"
" call void @b3()\n"
" ret void\n"
"}\n"
"define void @b3() {\n"
"entry:\n"
" call void @b1()\n"
" ret void\n"
"}\n"
"define void @c1() {\n"
"entry:\n"
" call void @c2()\n"
" call void @d2()\n"
" ret void\n"
"}\n"
"define void @c2() {\n"
"entry:\n"
" call void @c3()\n"
" ret void\n"
"}\n"
"define void @c3() {\n"
"entry:\n"
" call void @c1()\n"
" ret void\n"
"}\n"
"define void @d1() {\n"
"entry:\n"
" call void @d2()\n"
" ret void\n"
"}\n"
"define void @d2() {\n"
"entry:\n"
" call void @d3()\n"
" ret void\n"
"}\n"
"define void @d3() {\n"
"entry:\n"
" call void @d1()\n"
" ret void\n"
"}\n";
TEST(LazyCallGraphTest, BasicGraphFormation) {
std::unique_ptr<Module> M = parseAssembly(DiamondOfTriangles);
LazyCallGraph CG(*M);
// The order of the entry nodes should be stable w.r.t. the source order of
// the IR, and everything in our module is an entry node, so just directly
// build variables for each node.
auto I = CG.begin();
LazyCallGraph::Node &A1 = *I++;
EXPECT_EQ("a1", A1.getFunction().getName());
LazyCallGraph::Node &A2 = *I++;
EXPECT_EQ("a2", A2.getFunction().getName());
LazyCallGraph::Node &A3 = *I++;
EXPECT_EQ("a3", A3.getFunction().getName());
LazyCallGraph::Node &B1 = *I++;
EXPECT_EQ("b1", B1.getFunction().getName());
LazyCallGraph::Node &B2 = *I++;
EXPECT_EQ("b2", B2.getFunction().getName());
LazyCallGraph::Node &B3 = *I++;
EXPECT_EQ("b3", B3.getFunction().getName());
LazyCallGraph::Node &C1 = *I++;
EXPECT_EQ("c1", C1.getFunction().getName());
LazyCallGraph::Node &C2 = *I++;
EXPECT_EQ("c2", C2.getFunction().getName());
LazyCallGraph::Node &C3 = *I++;
EXPECT_EQ("c3", C3.getFunction().getName());
LazyCallGraph::Node &D1 = *I++;
EXPECT_EQ("d1", D1.getFunction().getName());
LazyCallGraph::Node &D2 = *I++;
EXPECT_EQ("d2", D2.getFunction().getName());
LazyCallGraph::Node &D3 = *I++;
EXPECT_EQ("d3", D3.getFunction().getName());
EXPECT_EQ(CG.end(), I);
// Build vectors and sort them for the rest of the assertions to make them
// independent of order.
std::vector<std::string> Nodes;
for (LazyCallGraph::Node &N : A1)
Nodes.push_back(N.getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ("a2", Nodes[0]);
EXPECT_EQ("b2", Nodes[1]);
EXPECT_EQ("c3", Nodes[2]);
Nodes.clear();
EXPECT_EQ(A2.end(), std::next(A2.begin()));
EXPECT_EQ("a3", A2.begin()->getFunction().getName());
EXPECT_EQ(A3.end(), std::next(A3.begin()));
EXPECT_EQ("a1", A3.begin()->getFunction().getName());
for (LazyCallGraph::Node &N : B1)
Nodes.push_back(N.getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ("b2", Nodes[0]);
EXPECT_EQ("d3", Nodes[1]);
Nodes.clear();
EXPECT_EQ(B2.end(), std::next(B2.begin()));
EXPECT_EQ("b3", B2.begin()->getFunction().getName());
EXPECT_EQ(B3.end(), std::next(B3.begin()));
EXPECT_EQ("b1", B3.begin()->getFunction().getName());
for (LazyCallGraph::Node &N : C1)
Nodes.push_back(N.getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ("c2", Nodes[0]);
EXPECT_EQ("d2", Nodes[1]);
Nodes.clear();
EXPECT_EQ(C2.end(), std::next(C2.begin()));
EXPECT_EQ("c3", C2.begin()->getFunction().getName());
EXPECT_EQ(C3.end(), std::next(C3.begin()));
EXPECT_EQ("c1", C3.begin()->getFunction().getName());
EXPECT_EQ(D1.end(), std::next(D1.begin()));
EXPECT_EQ("d2", D1.begin()->getFunction().getName());
EXPECT_EQ(D2.end(), std::next(D2.begin()));
EXPECT_EQ("d3", D2.begin()->getFunction().getName());
EXPECT_EQ(D3.end(), std::next(D3.begin()));
EXPECT_EQ("d1", D3.begin()->getFunction().getName());
// Now lets look at the SCCs.
auto SCCI = CG.postorder_scc_begin();
LazyCallGraph::SCC &D = *SCCI++;
for (LazyCallGraph::Node *N : D)
Nodes.push_back(N->getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ(3u, Nodes.size());
EXPECT_EQ("d1", Nodes[0]);
EXPECT_EQ("d2", Nodes[1]);
EXPECT_EQ("d3", Nodes[2]);
Nodes.clear();
EXPECT_FALSE(D.isParentOf(D));
EXPECT_FALSE(D.isChildOf(D));
EXPECT_FALSE(D.isAncestorOf(D));
EXPECT_FALSE(D.isDescendantOf(D));
LazyCallGraph::SCC &C = *SCCI++;
for (LazyCallGraph::Node *N : C)
Nodes.push_back(N->getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ(3u, Nodes.size());
EXPECT_EQ("c1", Nodes[0]);
EXPECT_EQ("c2", Nodes[1]);
EXPECT_EQ("c3", Nodes[2]);
Nodes.clear();
EXPECT_TRUE(C.isParentOf(D));
EXPECT_FALSE(C.isChildOf(D));
EXPECT_TRUE(C.isAncestorOf(D));
EXPECT_FALSE(C.isDescendantOf(D));
LazyCallGraph::SCC &B = *SCCI++;
for (LazyCallGraph::Node *N : B)
Nodes.push_back(N->getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ(3u, Nodes.size());
EXPECT_EQ("b1", Nodes[0]);
EXPECT_EQ("b2", Nodes[1]);
EXPECT_EQ("b3", Nodes[2]);
Nodes.clear();
EXPECT_TRUE(B.isParentOf(D));
EXPECT_FALSE(B.isChildOf(D));
EXPECT_TRUE(B.isAncestorOf(D));
EXPECT_FALSE(B.isDescendantOf(D));
EXPECT_FALSE(B.isAncestorOf(C));
EXPECT_FALSE(C.isAncestorOf(B));
LazyCallGraph::SCC &A = *SCCI++;
for (LazyCallGraph::Node *N : A)
Nodes.push_back(N->getFunction().getName());
std::sort(Nodes.begin(), Nodes.end());
EXPECT_EQ(3u, Nodes.size());
EXPECT_EQ("a1", Nodes[0]);
EXPECT_EQ("a2", Nodes[1]);
EXPECT_EQ("a3", Nodes[2]);
Nodes.clear();
EXPECT_TRUE(A.isParentOf(B));
EXPECT_TRUE(A.isParentOf(C));
EXPECT_FALSE(A.isParentOf(D));
EXPECT_TRUE(A.isAncestorOf(B));
EXPECT_TRUE(A.isAncestorOf(C));
EXPECT_TRUE(A.isAncestorOf(D));
EXPECT_EQ(CG.postorder_scc_end(), SCCI);
}
static Function &lookupFunction(Module &M, StringRef Name) {
for (Function &F : M)
if (F.getName() == Name)
return F;
report_fatal_error("Couldn't find function!");
}
TEST(LazyCallGraphTest, BasicGraphMutation) {
std::unique_ptr<Module> M = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @b()\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" ret void\n"
"}\n"
"define void @c() {\n"
"entry:\n"
" ret void\n"
"}\n");
LazyCallGraph CG(*M);
LazyCallGraph::Node &A = CG.get(lookupFunction(*M, "a"));
LazyCallGraph::Node &B = CG.get(lookupFunction(*M, "b"));
EXPECT_EQ(2, std::distance(A.begin(), A.end()));
EXPECT_EQ(0, std::distance(B.begin(), B.end()));
CG.insertEdge(B, lookupFunction(*M, "c"));
EXPECT_EQ(1, std::distance(B.begin(), B.end()));
LazyCallGraph::Node &C = *B.begin();
EXPECT_EQ(0, std::distance(C.begin(), C.end()));
CG.insertEdge(C, B.getFunction());
EXPECT_EQ(1, std::distance(C.begin(), C.end()));
EXPECT_EQ(&B, &*C.begin());
CG.insertEdge(C, C.getFunction());
EXPECT_EQ(2, std::distance(C.begin(), C.end()));
EXPECT_EQ(&B, &*C.begin());
EXPECT_EQ(&C, &*std::next(C.begin()));
CG.removeEdge(C, B.getFunction());
EXPECT_EQ(1, std::distance(C.begin(), C.end()));
EXPECT_EQ(&C, &*C.begin());
CG.removeEdge(C, C.getFunction());
EXPECT_EQ(0, std::distance(C.begin(), C.end()));
CG.removeEdge(B, C.getFunction());
EXPECT_EQ(0, std::distance(B.begin(), B.end()));
}
TEST(LazyCallGraphTest, MultiArmSCC) {
// Two interlocking cycles. The really useful thing about this SCC is that it
// will require Tarjan's DFS to backtrack and finish processing all of the
// children of each node in the SCC.
std::unique_ptr<Module> M = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @b()\n"
" call void @d()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @c() {\n"
"entry:\n"
" call void @a()\n"
" ret void\n"
"}\n"
"define void @d() {\n"
"entry:\n"
" call void @e()\n"
" ret void\n"
"}\n"
"define void @e() {\n"
"entry:\n"
" call void @a()\n"
" ret void\n"
"}\n");
LazyCallGraph CG(*M);
// Force the graph to be fully expanded.
auto SCCI = CG.postorder_scc_begin();
LazyCallGraph::SCC &SCC = *SCCI++;
EXPECT_EQ(CG.postorder_scc_end(), SCCI);
LazyCallGraph::Node &A = *CG.lookup(lookupFunction(*M, "a"));
LazyCallGraph::Node &B = *CG.lookup(lookupFunction(*M, "b"));
LazyCallGraph::Node &C = *CG.lookup(lookupFunction(*M, "c"));
LazyCallGraph::Node &D = *CG.lookup(lookupFunction(*M, "d"));
LazyCallGraph::Node &E = *CG.lookup(lookupFunction(*M, "e"));
EXPECT_EQ(&SCC, CG.lookupSCC(A));
EXPECT_EQ(&SCC, CG.lookupSCC(B));
EXPECT_EQ(&SCC, CG.lookupSCC(C));
EXPECT_EQ(&SCC, CG.lookupSCC(D));
EXPECT_EQ(&SCC, CG.lookupSCC(E));
}
TEST(LazyCallGraphTest, OutgoingSCCEdgeInsertion) {
std::unique_ptr<Module> M = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @b()\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" call void @d()\n"
" ret void\n"
"}\n"
"define void @c() {\n"
"entry:\n"
" call void @d()\n"
" ret void\n"
"}\n"
"define void @d() {\n"
"entry:\n"
" ret void\n"
"}\n");
LazyCallGraph CG(*M);
// Force the graph to be fully expanded.
for (LazyCallGraph::SCC &C : CG.postorder_sccs())
(void)C;
LazyCallGraph::Node &A = *CG.lookup(lookupFunction(*M, "a"));
LazyCallGraph::Node &B = *CG.lookup(lookupFunction(*M, "b"));
LazyCallGraph::Node &C = *CG.lookup(lookupFunction(*M, "c"));
LazyCallGraph::Node &D = *CG.lookup(lookupFunction(*M, "d"));
LazyCallGraph::SCC &AC = *CG.lookupSCC(A);
LazyCallGraph::SCC &BC = *CG.lookupSCC(B);
LazyCallGraph::SCC &CC = *CG.lookupSCC(C);
LazyCallGraph::SCC &DC = *CG.lookupSCC(D);
EXPECT_TRUE(AC.isAncestorOf(BC));
EXPECT_TRUE(AC.isAncestorOf(CC));
EXPECT_TRUE(AC.isAncestorOf(DC));
EXPECT_TRUE(DC.isDescendantOf(AC));
EXPECT_TRUE(DC.isDescendantOf(BC));
EXPECT_TRUE(DC.isDescendantOf(CC));
EXPECT_EQ(2, std::distance(A.begin(), A.end()));
AC.insertOutgoingEdge(A, D);
EXPECT_EQ(3, std::distance(A.begin(), A.end()));
EXPECT_TRUE(AC.isParentOf(DC));
EXPECT_EQ(&AC, CG.lookupSCC(A));
EXPECT_EQ(&BC, CG.lookupSCC(B));
EXPECT_EQ(&CC, CG.lookupSCC(C));
EXPECT_EQ(&DC, CG.lookupSCC(D));
}
TEST(LazyCallGraphTest, IncomingSCCEdgeInsertion) {
// We want to ensure we can add edges even across complex diamond graphs, so
// we use the diamond of triangles graph defined above. The ascii diagram is
// repeated here for easy reference.
//
// d1 |
// / \ |
// d3--d2 |
// / \ |
// b1 c1 |
// / \ / \ |
// b3--b2 c3--c2 |
// \ / |
// a1 |
// / \ |
// a3--a2 |
//
std::unique_ptr<Module> M = parseAssembly(DiamondOfTriangles);
LazyCallGraph CG(*M);
// Force the graph to be fully expanded.
for (LazyCallGraph::SCC &C : CG.postorder_sccs())
(void)C;
LazyCallGraph::Node &A1 = *CG.lookup(lookupFunction(*M, "a1"));
LazyCallGraph::Node &A2 = *CG.lookup(lookupFunction(*M, "a2"));
LazyCallGraph::Node &A3 = *CG.lookup(lookupFunction(*M, "a3"));
LazyCallGraph::Node &B1 = *CG.lookup(lookupFunction(*M, "b1"));
LazyCallGraph::Node &B2 = *CG.lookup(lookupFunction(*M, "b2"));
LazyCallGraph::Node &B3 = *CG.lookup(lookupFunction(*M, "b3"));
LazyCallGraph::Node &C1 = *CG.lookup(lookupFunction(*M, "c1"));
LazyCallGraph::Node &C2 = *CG.lookup(lookupFunction(*M, "c2"));
LazyCallGraph::Node &C3 = *CG.lookup(lookupFunction(*M, "c3"));
LazyCallGraph::Node &D1 = *CG.lookup(lookupFunction(*M, "d1"));
LazyCallGraph::Node &D2 = *CG.lookup(lookupFunction(*M, "d2"));
LazyCallGraph::Node &D3 = *CG.lookup(lookupFunction(*M, "d3"));
LazyCallGraph::SCC &AC = *CG.lookupSCC(A1);
LazyCallGraph::SCC &BC = *CG.lookupSCC(B1);
LazyCallGraph::SCC &CC = *CG.lookupSCC(C1);
LazyCallGraph::SCC &DC = *CG.lookupSCC(D1);
ASSERT_EQ(&AC, CG.lookupSCC(A2));
ASSERT_EQ(&AC, CG.lookupSCC(A3));
ASSERT_EQ(&BC, CG.lookupSCC(B2));
ASSERT_EQ(&BC, CG.lookupSCC(B3));
ASSERT_EQ(&CC, CG.lookupSCC(C2));
ASSERT_EQ(&CC, CG.lookupSCC(C3));
ASSERT_EQ(&DC, CG.lookupSCC(D2));
ASSERT_EQ(&DC, CG.lookupSCC(D3));
ASSERT_EQ(1, std::distance(D2.begin(), D2.end()));
// Add an edge to make the graph:
//
// d1 |
// / \ |
// d3--d2---. |
// / \ | |
// b1 c1 | |
// / \ / \ / |
// b3--b2 c3--c2 |
// \ / |
// a1 |
// / \ |
// a3--a2 |
CC.insertIncomingEdge(D2, C2);
// Make sure we connected the nodes.
EXPECT_EQ(2, std::distance(D2.begin(), D2.end()));
// Make sure we have the correct nodes in the SCC sets.
EXPECT_EQ(&AC, CG.lookupSCC(A1));
EXPECT_EQ(&AC, CG.lookupSCC(A2));
EXPECT_EQ(&AC, CG.lookupSCC(A3));
EXPECT_EQ(&BC, CG.lookupSCC(B1));
EXPECT_EQ(&BC, CG.lookupSCC(B2));
EXPECT_EQ(&BC, CG.lookupSCC(B3));
EXPECT_EQ(&CC, CG.lookupSCC(C1));
EXPECT_EQ(&CC, CG.lookupSCC(C2));
EXPECT_EQ(&CC, CG.lookupSCC(C3));
EXPECT_EQ(&CC, CG.lookupSCC(D1));
EXPECT_EQ(&CC, CG.lookupSCC(D2));
EXPECT_EQ(&CC, CG.lookupSCC(D3));
// And that ancestry tests have been updated.
EXPECT_TRUE(AC.isParentOf(BC));
EXPECT_TRUE(AC.isParentOf(CC));
EXPECT_FALSE(AC.isAncestorOf(DC));
EXPECT_FALSE(BC.isAncestorOf(DC));
EXPECT_FALSE(CC.isAncestorOf(DC));
}
TEST(LazyCallGraphTest, IncomingSCCEdgeInsertionMidTraversal) {
// This is the same fundamental test as the previous, but we perform it
// having only partially walked the SCCs of the graph.
std::unique_ptr<Module> M = parseAssembly(DiamondOfTriangles);
LazyCallGraph CG(*M);
// Walk the SCCs until we find the one containing 'c1'.
auto SCCI = CG.postorder_scc_begin(), SCCE = CG.postorder_scc_end();
ASSERT_NE(SCCI, SCCE);
LazyCallGraph::SCC &DC = *SCCI;
ASSERT_NE(&DC, nullptr);
++SCCI;
ASSERT_NE(SCCI, SCCE);
LazyCallGraph::SCC &CC = *SCCI;
ASSERT_NE(&CC, nullptr);
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "a1")));
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "a2")));
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "a3")));
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "b1")));
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "b2")));
ASSERT_EQ(nullptr, CG.lookup(lookupFunction(*M, "b3")));
LazyCallGraph::Node &C1 = *CG.lookup(lookupFunction(*M, "c1"));
LazyCallGraph::Node &C2 = *CG.lookup(lookupFunction(*M, "c2"));
LazyCallGraph::Node &C3 = *CG.lookup(lookupFunction(*M, "c3"));
LazyCallGraph::Node &D1 = *CG.lookup(lookupFunction(*M, "d1"));
LazyCallGraph::Node &D2 = *CG.lookup(lookupFunction(*M, "d2"));
LazyCallGraph::Node &D3 = *CG.lookup(lookupFunction(*M, "d3"));
ASSERT_EQ(&CC, CG.lookupSCC(C1));
ASSERT_EQ(&CC, CG.lookupSCC(C2));
ASSERT_EQ(&CC, CG.lookupSCC(C3));
ASSERT_EQ(&DC, CG.lookupSCC(D1));
ASSERT_EQ(&DC, CG.lookupSCC(D2));
ASSERT_EQ(&DC, CG.lookupSCC(D3));
ASSERT_EQ(1, std::distance(D2.begin(), D2.end()));
CC.insertIncomingEdge(D2, C2);
EXPECT_EQ(2, std::distance(D2.begin(), D2.end()));
// Make sure we have the correct nodes in the SCC sets.
EXPECT_EQ(&CC, CG.lookupSCC(C1));
EXPECT_EQ(&CC, CG.lookupSCC(C2));
EXPECT_EQ(&CC, CG.lookupSCC(C3));
EXPECT_EQ(&CC, CG.lookupSCC(D1));
EXPECT_EQ(&CC, CG.lookupSCC(D2));
EXPECT_EQ(&CC, CG.lookupSCC(D3));
// Check that we can form the last two SCCs now in a coherent way.
++SCCI;
EXPECT_NE(SCCI, SCCE);
LazyCallGraph::SCC &BC = *SCCI;
EXPECT_NE(&BC, nullptr);
EXPECT_EQ(&BC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "b1"))));
EXPECT_EQ(&BC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "b2"))));
EXPECT_EQ(&BC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "b3"))));
++SCCI;
EXPECT_NE(SCCI, SCCE);
LazyCallGraph::SCC &AC = *SCCI;
EXPECT_NE(&AC, nullptr);
EXPECT_EQ(&AC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "a1"))));
EXPECT_EQ(&AC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "a2"))));
EXPECT_EQ(&AC, CG.lookupSCC(*CG.lookup(lookupFunction(*M, "a3"))));
++SCCI;
EXPECT_EQ(SCCI, SCCE);
}
TEST(LazyCallGraphTest, InterSCCEdgeRemoval) {
std::unique_ptr<Module> M = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @b()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" ret void\n"
"}\n");
LazyCallGraph CG(*M);
// Force the graph to be fully expanded.
for (LazyCallGraph::SCC &C : CG.postorder_sccs())
(void)C;
LazyCallGraph::Node &A = *CG.lookup(lookupFunction(*M, "a"));
LazyCallGraph::Node &B = *CG.lookup(lookupFunction(*M, "b"));
LazyCallGraph::SCC &AC = *CG.lookupSCC(A);
LazyCallGraph::SCC &BC = *CG.lookupSCC(B);
EXPECT_EQ("b", A.begin()->getFunction().getName());
EXPECT_EQ(B.end(), B.begin());
EXPECT_EQ(&AC, &*BC.parent_begin());
AC.removeInterSCCEdge(A, B);
EXPECT_EQ(A.end(), A.begin());
EXPECT_EQ(B.end(), B.begin());
EXPECT_EQ(BC.parent_end(), BC.parent_begin());
}
TEST(LazyCallGraphTest, IntraSCCEdgeInsertion) {
std::unique_ptr<Module> M1 = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @b()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @c() {\n"
"entry:\n"
" call void @a()\n"
" ret void\n"
"}\n");
LazyCallGraph CG1(*M1);
// Force the graph to be fully expanded.
auto SCCI = CG1.postorder_scc_begin();
LazyCallGraph::SCC &SCC = *SCCI++;
EXPECT_EQ(CG1.postorder_scc_end(), SCCI);
LazyCallGraph::Node &A = *CG1.lookup(lookupFunction(*M1, "a"));
LazyCallGraph::Node &B = *CG1.lookup(lookupFunction(*M1, "b"));
LazyCallGraph::Node &C = *CG1.lookup(lookupFunction(*M1, "c"));
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(&SCC, CG1.lookupSCC(B));
EXPECT_EQ(&SCC, CG1.lookupSCC(C));
// Insert an edge from 'a' to 'c'. Nothing changes about the SCCs.
SCC.insertIntraSCCEdge(A, C);
EXPECT_EQ(2, std::distance(A.begin(), A.end()));
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(&SCC, CG1.lookupSCC(B));
EXPECT_EQ(&SCC, CG1.lookupSCC(C));
// Insert a self edge from 'a' back to 'a'.
SCC.insertIntraSCCEdge(A, A);
EXPECT_EQ(3, std::distance(A.begin(), A.end()));
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(&SCC, CG1.lookupSCC(B));
EXPECT_EQ(&SCC, CG1.lookupSCC(C));
}
TEST(LazyCallGraphTest, IntraSCCEdgeRemoval) {
// A nice fully connected (including self-edges) SCC.
std::unique_ptr<Module> M1 = parseAssembly(
"define void @a() {\n"
"entry:\n"
" call void @a()\n"
" call void @b()\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @b() {\n"
"entry:\n"
" call void @a()\n"
" call void @b()\n"
" call void @c()\n"
" ret void\n"
"}\n"
"define void @c() {\n"
"entry:\n"
" call void @a()\n"
" call void @b()\n"
" call void @c()\n"
" ret void\n"
"}\n");
LazyCallGraph CG1(*M1);
// Force the graph to be fully expanded.
auto SCCI = CG1.postorder_scc_begin();
LazyCallGraph::SCC &SCC = *SCCI++;
EXPECT_EQ(CG1.postorder_scc_end(), SCCI);
LazyCallGraph::Node &A = *CG1.lookup(lookupFunction(*M1, "a"));
LazyCallGraph::Node &B = *CG1.lookup(lookupFunction(*M1, "b"));
LazyCallGraph::Node &C = *CG1.lookup(lookupFunction(*M1, "c"));
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(&SCC, CG1.lookupSCC(B));
EXPECT_EQ(&SCC, CG1.lookupSCC(C));
// Remove the edge from b -> a, which should leave the 3 functions still in
// a single connected component because of a -> b -> c -> a.
SmallVector<LazyCallGraph::SCC *, 1> NewSCCs = SCC.removeIntraSCCEdge(B, A);
EXPECT_EQ(0u, NewSCCs.size());
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(&SCC, CG1.lookupSCC(B));
EXPECT_EQ(&SCC, CG1.lookupSCC(C));
// Remove the edge from c -> a, which should leave 'a' in the original SCC
// and form a new SCC for 'b' and 'c'.
NewSCCs = SCC.removeIntraSCCEdge(C, A);
EXPECT_EQ(1u, NewSCCs.size());
EXPECT_EQ(&SCC, CG1.lookupSCC(A));
EXPECT_EQ(1, std::distance(SCC.begin(), SCC.end()));
LazyCallGraph::SCC *SCC2 = CG1.lookupSCC(B);
EXPECT_EQ(SCC2, CG1.lookupSCC(C));
EXPECT_EQ(SCC2, NewSCCs[0]);
}
}