llvm-6502/unittests/Analysis/LazyCallGraphTest.cpp
Chandler Carruth 9e9ec34760 [LCG] Re-order expectations to provide more useful output when debugging
an issue. This way you see that the number of nodes was wrong before
a crash due to accessing too many nodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207094 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 09:59:56 +00:00

396 lines
11 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();
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();
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();
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_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, 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, 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());
CG.removeEdge(A, lookupFunction(*M, "b"));
EXPECT_EQ(A.end(), A.begin());
EXPECT_EQ(B.end(), B.begin());
EXPECT_EQ(BC.parent_end(), BC.parent_begin());
}
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.
CG1.removeEdge(B, A.getFunction());
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'.
CG1.removeEdge(C, A.getFunction());
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));
}
}