// ParseSubGraph parses the provided DOT file into a subgraph with a dedicated
// entry and exit node. The entry and exit nodes are identified using the node
// "label" attribute, e.g.
//
// digraph if {
// A->B [label="true"]
// A->C [label="false"]
// B->C
// A [label="entry"]
// B
// C [label="exit"]
// }
func ParseSubGraph(path string) (*SubGraph, error) {
graph, err := dot.ParseFile(path)
if err != nil {
return nil, err
}
return NewSubGraph(graph)
}
func main() {
g, err := dot.ParseFile("dotu.dot")
if err != nil {
panic(err)
}
s := g.String()
fmt.Println(s)
}
// locateIntervals locates all intervals in the provided graph.
func locateIntervals(dotPath string) ([]*graphs.Interval, error) {
// Parse graph.
g, err := dot.ParseFile(dotPath)
if err != nil {
return nil, errutil.Err(err)
}
// Locate intervals
return graphs.GetIntervals(g), nil
}
// locate parses the provided graphs and tries to locate isomorphisms of the
// subgraph in the graph.
func locate(graphPath, subPath string) error {
// Parse graph.
graph, err := dot.ParseFile(graphPath)
if err != nil {
return errutil.Err(err)
}
// Search for subgraph in GOPATH if not found.
if ok, _ := osutil.Exists(subPath); !ok {
dir, err := goutil.SrcDir("decomp.org/decomp/graphs/testdata/primitives")
if err != nil {
return errutil.Err(err)
}
subPath = filepath.Join(dir, subPath)
}
sub, err := graphs.ParseSubGraph(subPath)
if err != nil {
return errutil.Err(err)
}
// Locate isomorphisms.
found := false
if len(flagStart) > 0 {
// Locate an isomorphism of sub in graph which starts at the node
// specified by the "-start" flag.
m, ok := iso.Isomorphism(graph, flagStart, sub)
if ok {
found = true
printMapping(graph, sub, m)
}
} else {
// Locate all isomorphisms of sub in graph.
var names []string
for name := range graph.Nodes.Lookup {
names = append(names, name)
}
sort.Strings(names)
for _, name := range names {
m, ok := iso.Isomorphism(graph, name, sub)
if !ok {
continue
}
found = true
printMapping(graph, sub, m)
}
}
if !found {
fmt.Println("not found.")
}
return nil
}
// restructure attempts to recover the control flow primitives of a given
// control flow graph. It does so by repeatedly locating and merging structured
// subgraphs (graph representations of control flow primitives) into single
// nodes until the entire graph is reduced into a single node or no structured
// subgraphs may be located. The list of primitives is ordered in the same
// sequence as they were located.
func restructure(dotPath string, subs []*graphs.SubGraph) (prims []*primitive.Primitive, err error) {
// Parse the unstructured CFG.
var graph *dot.Graph
switch dotPath {
case "-":
// Read from stdin.
buf, err := ioutil.ReadAll(os.Stdin)
if err != nil {
return nil, errutil.Err(err)
}
graph, err = dot.Read(buf)
if err != nil {
return nil, errutil.Err(err)
}
default:
// Read from FILE.
graph, err = dot.ParseFile(dotPath)
if err != nil {
return nil, errutil.Err(err)
}
}
if len(graph.Nodes.Nodes) == 0 {
return nil, errutil.Newf("unable to restructure empty graph %q", dotPath)
}
// Locate control flow primitives.
for step := 1; len(graph.Nodes.Nodes) > 1; step++ {
prim, err := findPrim(graph, subs, step)
if err != nil {
return nil, errutil.Err(err)
}
prims = append(prims, prim)
}
return prims, nil
}
// parseCFG parses the control flow graph of the function.
//
// For a source file "foo.ll" containing the functions "bar" and "baz" the
// following DOT files will be created:
//
// foo_graphs/bar.dot
// foo_graphs/baz.dot
func parseCFG(basePath, funcName string) (graph *dot.Graph, err error) {
dotDir := basePath + "_graphs"
dotName := funcName + ".dot"
dotPath := fmt.Sprintf("%s/%s", dotDir, dotName)
return dot.ParseFile(dotPath)
}
func TestEquationIsValid(t *testing.T) {
golden := []struct {
subPath string
graphPath string
eq *equation
want bool
}{
// i=0
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "71",
"body": "74",
"exit": "75",
},
},
want: true,
},
// i=1
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "17",
"body": "24",
"exit": "32",
},
},
want: true,
},
// i=2
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "89",
"body": "92",
"exit": "93",
},
},
want: false,
},
// i=3
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "94",
"body": "97",
"exit": "98",
},
},
want: false,
},
// i=4
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "282",
"body_true": "292",
"body_false": "287",
"exit": "299",
},
},
want: true,
},
// i=5
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "282",
"body_true": "287",
"body_false": "292",
"exit": "299",
},
},
want: true,
},
// i=6
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
eq: &equation{
m: map[string]string{
"cond": "438",
"body_true": "446",
"body_false": "443",
"exit": "447",
},
},
want: true,
},
// i=7
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
eq: &equation{
m: map[string]string{
"cond": "438",
"body_true": "443",
"body_false": "446",
"exit": "447",
},
},
want: true,
},
// i=8
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
eq: &equation{
m: map[string]string{
"cond": "487",
"body_true": "492",
"body_false": "495",
"exit": "496",
},
},
want: true,
},
// i=9
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
eq: &equation{
m: map[string]string{
"cond": "487",
"body_true": "495",
"body_false": "492",
"exit": "496",
},
},
want: true,
},
// i=10
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
eq: &equation{
m: map[string]string{
"cond": "124",
"body_true": "134",
"body_false": "126",
"exit": "145",
},
},
want: false,
},
// i=11
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/main.dot",
eq: &equation{
m: map[string]string{
"entry": "740",
"exit": "760",
},
},
want: true,
},
// i=12
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/main.dot",
eq: &equation{
m: map[string]string{
"entry": "761",
"exit": "762",
},
},
want: false,
},
// i=13
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "191",
"body": "194",
"exit": "196",
},
},
want: true,
},
// i=14
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "370",
"body": "378",
"exit": "374",
},
},
want: false,
},
// i=15
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "526",
"body": "530",
"exit": "539",
},
},
want: false,
},
// i=16
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "611",
"body_true": "615",
"body_false": "615",
"exit": "631",
},
},
want: false,
},
// i=17
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
eq: &equation{
m: map[string]string{
"cond": "611",
"body_true": "615",
"exit": "631",
},
},
want: false,
},
// i=18
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/main.dot",
eq: &equation{
m: map[string]string{
"cond": "20",
"body": "25",
"exit": "34",
},
},
want: false,
},
// i=19
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "39", // 48
"body": "44",
"exit": "52", // 45
},
},
want: false,
},
// i=20
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
eq: &equation{
m: map[string]string{
"cond": "39",
"body": "44",
"exit": "45",
},
},
want: false,
},
}
for i, g := range golden {
sub, err := graphs.ParseSubGraph(g.subPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
graph, err := dot.ParseFile(g.graphPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
got := g.eq.isValid(graph, sub)
if got != g.want {
t.Errorf("i=%d: ok mismatch; expected %v, got %v", i, g.want, got)
continue
}
}
}
func TestSolveBrute(t *testing.T) {
golden := []struct {
subPath string
graphPath string
entry string
wants []map[string]string
err string
}{
// i=0
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/primitives/if_else.dot",
entry: "cond",
wants: []map[string]string{
{
"cond": "cond",
"body_true": "body_true",
"body_false": "body_false",
"exit": "exit",
},
{
"cond": "cond",
"body_true": "body_false",
"body_false": "body_true",
"exit": "exit",
},
},
err: "",
},
// i=1
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "85",
wants: []map[string]string{nil},
err: "unable to locate node pair mapping",
},
// i=2
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "71",
wants: []map[string]string{nil},
err: "unable to locate node pair mapping",
},
// i=3
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "89",
wants: []map[string]string{
{
"cond": "89",
"body": "92",
"exit": "93",
},
},
},
// i=4
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "71",
wants: []map[string]string{
{
"cond": "71",
"body": "74",
"exit": "75",
},
},
},
}
loop:
for i, g := range golden {
graph, err := dot.ParseFile(g.graphPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
sub, err := graphs.ParseSubGraph(g.subPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
eq, err := candidates(graph, g.entry, sub)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
m, err := eq.solveBrute(graph, sub)
if !sameError(err, g.err) {
t.Errorf("i=%d: error mismatch; expected %v, got %v", i, g.err, err)
continue
} else if err != nil {
// Expected error, check next test case.
continue
}
for _, want := range g.wants {
if reflect.DeepEqual(m, want) {
continue loop
}
}
t.Errorf("i=%d: node pair map mismatch; expected one of %v, got %v", i, g.wants, m)
}
}
func TestSearch(t *testing.T) {
golden := []struct {
subPath string
graphPath string
m map[string]string
ok bool
}{
// i=0
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
m: map[string]string{
"cond": "17",
"body": "24",
"exit": "32",
},
ok: true,
},
// i=1
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
m: nil,
ok: false,
},
// i=2
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
m: map[string]string{
"entry": "101",
"exit": "105",
},
ok: true,
},
// i=3
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
m: map[string]string{
"cond": "89",
"body": "92",
"exit": "93",
},
ok: true,
},
// i=4
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
m: map[string]string{
"cond": "120",
"body": "122",
"exit": "127",
},
ok: true,
},
// i=5
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
m: map[string]string{
"cond": "282",
"body_true": "292",
"body_false": "287",
"exit": "299",
},
ok: true,
},
// i=6
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
m: map[string]string{
"entry": "109",
"exit": "119",
},
ok: true,
},
// i=7
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/expr.dot",
m: map[string]string{
"cond": "191",
"body": "194",
"exit": "196",
},
ok: true,
},
// i=8
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/next.dot",
m: map[string]string{
"cond": "195",
"body": "200",
"exit": "205",
},
ok: true,
},
// i=9
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/next.dot",
m: map[string]string{
"cond": "28",
"body_true": "44",
"body_false": "39",
"exit": "46",
},
ok: true,
},
// i=10
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/next.dot",
m: map[string]string{
"entry": "320",
"exit": "322",
},
ok: true,
},
// i=11
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/next.dot",
m: nil,
ok: false,
},
// i=12
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/main.dot",
m: map[string]string{
"cond": "135",
"body": "138",
"exit": "139",
},
ok: true,
},
// i=13
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/main.dot",
m: map[string]string{
"cond": "442",
"body_true": "451",
"body_false": "448",
"exit": "453",
},
ok: true,
},
// i=14
{
subPath: "../testdata/primitives/list.dot",
graphPath: "../testdata/c4_graphs/main.dot",
m: map[string]string{
"entry": "740",
"exit": "760",
},
ok: true,
},
// i=15
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/main.dot",
m: map[string]string{
"cond": "190",
"body": "193",
"exit": "195",
},
ok: true,
},
}
for i, g := range golden {
sub, err := graphs.ParseSubGraph(g.subPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
graph, err := dot.ParseFile(g.graphPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
m, ok := Search(graph, sub)
if ok != g.ok {
t.Errorf("i=%d: ok mismatch; expected %v, got %v", i, g.ok, ok)
continue
}
if !reflect.DeepEqual(m, g.m) {
t.Errorf("i=%d: node pair mapping mismatch; expected %v, got %v", i, g.m, m)
}
}
}
func TestCandidates(t *testing.T) {
golden := []struct {
subPath string
graphPath string
entry string
want map[string]map[string]bool
err string
}{
// i=0
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/primitives/if_else.dot",
entry: "cond",
want: map[string]map[string]bool{
"cond": {
"cond": true,
},
"body_true": {
"body_true": true,
"body_false": true,
},
"body_false": {
"body_true": true,
"body_false": true,
},
"exit": {
"exit": true,
},
},
err: "",
},
// i=1
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "85",
want: map[string]map[string]bool{
"cond": {
"85": true,
},
"body_true": {
"88": true,
},
"body_false": {
"88": true,
},
"exit": {
"89": true,
},
},
err: "",
},
// i=2
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "71",
want: map[string]map[string]bool{
"cond": {
"71": true,
},
"body": {
"74": true,
},
"exit": {
"74": true,
},
},
err: "",
},
// i=3
{
subPath: "../testdata/primitives/pre_loop.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "89",
want: map[string]map[string]bool{
"cond": {
"89": true,
},
"body": {
"92": true,
"93": true,
},
"exit": {
"92": true,
"93": true,
},
},
err: "",
},
// i=4
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "71",
want: map[string]map[string]bool{
"cond": {
"71": true,
},
"body": {
"74": true,
},
"exit": {
"75": true,
},
},
err: "",
},
// i=5
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "foo",
want: nil,
err: `unable to locate entry node "foo" in graph`,
},
// i=6
{
subPath: "../testdata/primitives/if.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "97",
want: nil,
err: `invalid entry node candidate "97"; expected 2 successors, got 1`,
},
// i=7
{
subPath: "../testdata/primitives/if_else.dot",
graphPath: "../testdata/c4_graphs/stmt.dot",
entry: "68",
want: nil,
err: "incomplete candidate mapping; expected 4 map entites, got 1",
},
}
for i, g := range golden {
sub, err := graphs.ParseSubGraph(g.subPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
graph, err := dot.ParseFile(g.graphPath)
if err != nil {
t.Errorf("i=%d: %v", i, err)
continue
}
eq, err := candidates(graph, g.entry, sub)
if !sameError(err, g.err) {
t.Errorf("i=%d: error mismatch; expected %v, got %v", i, g.err, err)
continue
} else if err != nil {
// Expected error, check next test case.
continue
}
if !reflect.DeepEqual(eq.c, g.want) {
t.Errorf("i=%d: candidate map mismatch; expected %v, got %v", i, g.want, eq.c)
}
}
}
// locateAndMerge parses the provided graphs and tries to merge isomorphisms of
// the subgraph in the graph into single nodes.
func locateAndMerge(graphPath, subPath string) error {
// Parse graph.
graph, err := dot.ParseFile(graphPath)
if err != nil {
return errutil.Err(err)
}
// Search for subgraph in GOPATH if not found.
if ok, _ := osutil.Exists(subPath); !ok {
dir, err := goutil.SrcDir("decomp.org/decomp/graphs/testdata/primitives")
if err != nil {
return errutil.Err(err)
}
subPath = filepath.Join(dir, subPath)
}
sub, err := graphs.ParseSubGraph(subPath)
if err != nil {
return errutil.Err(err)
}
// Merge isomorphisms.
found := false
if len(flagStart) > 0 {
// Merge an isomorphism of sub in graph which starts at the node
// specified by the "-start" flag.
m, ok := iso.Isomorphism(graph, flagStart, sub)
if ok {
found = true
printMapping(graph, sub, m)
_, err := merge.Merge(graph, m, sub)
if err != nil {
return errutil.Err(err)
}
}
} else {
// Merge all isomorphisms of sub in graph.
for {
m, ok := iso.Search(graph, sub)
if !ok {
break
}
found = true
printMapping(graph, sub, m)
_, err := merge.Merge(graph, m, sub)
if err != nil {
return errutil.Err(err)
}
}
}
// Store DOT and PNG representation of graph.
if found {
err = dump(graph)
if err != nil {
return errutil.Err(err)
}
} else {
fmt.Println("not found.")
}
return nil
}