Beispiel #1
0
func TestSwitches(t *testing.T) {
	conf := loader.Config{ParserMode: parser.ParseComments}
	f, err := conf.ParseFile("testdata/switches.go", nil)
	if err != nil {
		t.Error(err)
		return
	}

	conf.CreateFromFiles("main", f)
	iprog, err := conf.Load()
	if err != nil {
		t.Error(err)
		return
	}

	prog := ssa.Create(iprog, 0)
	mainPkg := prog.Package(iprog.Created[0].Pkg)
	mainPkg.Build()

	for _, mem := range mainPkg.Members {
		if fn, ok := mem.(*ssa.Function); ok {
			if fn.Synthetic != "" {
				continue // e.g. init()
			}
			// Each (multi-line) "switch" comment within
			// this function must match the printed form
			// of a ConstSwitch.
			var wantSwitches []string
			for _, c := range f.Comments {
				if fn.Syntax().Pos() <= c.Pos() && c.Pos() < fn.Syntax().End() {
					text := strings.TrimSpace(c.Text())
					if strings.HasPrefix(text, "switch ") {
						wantSwitches = append(wantSwitches, text)
					}
				}
			}

			switches := ssautil.Switches(fn)
			if len(switches) != len(wantSwitches) {
				t.Errorf("in %s, found %d switches, want %d", fn, len(switches), len(wantSwitches))
			}
			for i, sw := range switches {
				got := sw.String()
				if i >= len(wantSwitches) {
					continue
				}
				want := wantSwitches[i]
				if got != want {
					t.Errorf("in %s, found switch %d: got <<%s>>, want <<%s>>", fn, i, got, want)
				}
			}
		}
	}
}
Beispiel #2
0
func create(t *testing.T, content string) []*ssa.Package {
	var conf loader.Config
	f, err := conf.ParseFile("foo_test.go", content)
	if err != nil {
		t.Fatal(err)
	}
	conf.CreateFromFiles("foo", f)

	iprog, err := conf.Load()
	if err != nil {
		t.Fatal(err)
	}

	// We needn't call Build.
	return ssa.Create(iprog, ssa.SanityCheckFunctions).AllPackages()
}
// Tests that programs partially loaded from gc object files contain
// functions with no code for the external portions, but are otherwise ok.
func TestExternalPackages(t *testing.T) {
	test := `
package main

import (
	"bytes"
	"io"
	"testing"
)

func main() {
        var t testing.T
	t.Parallel()    // static call to external declared method
        t.Fail()        // static call to promoted external declared method
        testing.Short() // static call to external package-level function

        var w io.Writer = new(bytes.Buffer)
        w.Write(nil)    // interface invoke of external declared method
}
`

	// Create a single-file main package.
	var conf loader.Config
	f, err := conf.ParseFile("<input>", test, 0)
	if err != nil {
		t.Error(err)
		return
	}
	conf.CreateFromFiles("main", f)

	iprog, err := conf.Load()
	if err != nil {
		t.Error(err)
		return
	}

	prog := ssa.Create(iprog, ssa.SanityCheckFunctions)
	mainPkg := prog.Package(iprog.Created[0].Pkg)
	mainPkg.Build()

	// The main package, its direct and indirect dependencies are loaded.
	deps := []string{
		// directly imported dependencies:
		"bytes", "io", "testing",
		// indirect dependencies (partial list):
		"errors", "fmt", "os", "runtime",
	}

	all := prog.AllPackages()
	if len(all) <= len(deps) {
		t.Errorf("unexpected set of loaded packages: %q", all)
	}
	for _, path := range deps {
		pkg := prog.ImportedPackage(path)
		if pkg == nil {
			t.Errorf("package not loaded: %q", path)
			continue
		}

		// External packages should have no function bodies (except for wrappers).
		isExt := pkg != mainPkg

		// init()
		if isExt && !isEmpty(pkg.Func("init")) {
			t.Errorf("external package %s has non-empty init", pkg)
		} else if !isExt && isEmpty(pkg.Func("init")) {
			t.Errorf("main package %s has empty init", pkg)
		}

		for _, mem := range pkg.Members {
			switch mem := mem.(type) {
			case *ssa.Function:
				// Functions at package level.
				if isExt && !isEmpty(mem) {
					t.Errorf("external function %s is non-empty", mem)
				} else if !isExt && isEmpty(mem) {
					t.Errorf("function %s is empty", mem)
				}

			case *ssa.Type:
				// Methods of named types T.
				// (In this test, all exported methods belong to *T not T.)
				if !isExt {
					t.Fatalf("unexpected name type in main package: %s", mem)
				}
				mset := prog.MethodSets.MethodSet(types.NewPointer(mem.Type()))
				for i, n := 0, mset.Len(); i < n; i++ {
					m := prog.Method(mset.At(i))
					// For external types, only synthetic wrappers have code.
					expExt := !strings.Contains(m.Synthetic, "wrapper")
					if expExt && !isEmpty(m) {
						t.Errorf("external method %s is non-empty: %s",
							m, m.Synthetic)
					} else if !expExt && isEmpty(m) {
						t.Errorf("method function %s is empty: %s",
							m, m.Synthetic)
					}
				}
			}
		}
	}

	expectedCallee := []string{
		"(*testing.T).Parallel",
		"(*testing.common).Fail",
		"testing.Short",
		"N/A",
	}
	callNum := 0
	for _, b := range mainPkg.Func("main").Blocks {
		for _, instr := range b.Instrs {
			switch instr := instr.(type) {
			case ssa.CallInstruction:
				call := instr.Common()
				if want := expectedCallee[callNum]; want != "N/A" {
					got := call.StaticCallee().String()
					if want != got {
						t.Errorf("call #%d from main.main: got callee %s, want %s",
							callNum, got, want)
					}
				}
				callNum++
			}
		}
	}
	if callNum != 4 {
		t.Errorf("in main.main: got %d calls, want %d", callNum, 4)
	}
}
// TestTypesWithMethodSets tests that Package.TypesWithMethodSets includes all necessary types.
func TestTypesWithMethodSets(t *testing.T) {
	tests := []struct {
		input string
		want  []string
	}{
		// An exported package-level type is needed.
		{`package A; type T struct{}; func (T) f() {}`,
			[]string{"*p.T", "p.T"},
		},
		// An unexported package-level type is not needed.
		{`package B; type t struct{}; func (t) f() {}`,
			nil,
		},
		// Subcomponents of type of exported package-level var are needed.
		{`package C; import "bytes"; var V struct {*bytes.Buffer}`,
			[]string{"*struct{*bytes.Buffer}", "struct{*bytes.Buffer}"},
		},
		// Subcomponents of type of unexported package-level var are not needed.
		{`package D; import "bytes"; var v struct {*bytes.Buffer}`,
			nil,
		},
		// Subcomponents of type of exported package-level function are needed.
		{`package E; import "bytes"; func F(struct {*bytes.Buffer}) {}`,
			[]string{"struct{*bytes.Buffer}"},
		},
		// Subcomponents of type of unexported package-level function are not needed.
		{`package F; import "bytes"; func f(struct {*bytes.Buffer}) {}`,
			nil,
		},
		// Subcomponents of type of exported method of uninstantiated unexported type are not needed.
		{`package G; import "bytes"; type x struct{}; func (x) G(struct {*bytes.Buffer}) {}; var v x`,
			nil,
		},
		// ...unless used by MakeInterface.
		{`package G2; import "bytes"; type x struct{}; func (x) G(struct {*bytes.Buffer}) {}; var v interface{} = x{}`,
			[]string{"*p.x", "p.x", "struct{*bytes.Buffer}"},
		},
		// Subcomponents of type of unexported method are not needed.
		{`package I; import "bytes"; type X struct{}; func (X) G(struct {*bytes.Buffer}) {}`,
			[]string{"*p.X", "p.X", "struct{*bytes.Buffer}"},
		},
		// Local types aren't needed.
		{`package J; import "bytes"; func f() { type T struct {*bytes.Buffer}; var t T; _ = t }`,
			nil,
		},
		// ...unless used by MakeInterface.
		{`package K; import "bytes"; func f() { type T struct {*bytes.Buffer}; _ = interface{}(T{}) }`,
			[]string{"*p.T", "p.T"},
		},
		// Types used as operand of MakeInterface are needed.
		{`package L; import "bytes"; func f() { _ = interface{}(struct{*bytes.Buffer}{}) }`,
			[]string{"struct{*bytes.Buffer}"},
		},
		// MakeInterface is optimized away when storing to a blank.
		{`package M; import "bytes"; var _ interface{} = struct{*bytes.Buffer}{}`,
			nil,
		},
	}
	for _, test := range tests {
		// Create a single-file main package.
		var conf loader.Config
		f, err := conf.ParseFile("<input>", test.input, 0)
		if err != nil {
			t.Errorf("test %q: %s", test.input[:15], err)
			continue
		}
		conf.CreateFromFiles("p", f)

		iprog, err := conf.Load()
		if err != nil {
			t.Errorf("test 'package %s': Load: %s", f.Name.Name, err)
			continue
		}
		prog := ssa.Create(iprog, ssa.SanityCheckFunctions)
		mainPkg := prog.Package(iprog.Created[0].Pkg)
		prog.BuildAll()

		var typstrs []string
		for _, T := range mainPkg.TypesWithMethodSets() {
			typstrs = append(typstrs, T.String())
		}
		sort.Strings(typstrs)

		if !reflect.DeepEqual(typstrs, test.want) {
			t.Errorf("test 'package %s': got %q, want %q", f.Name.Name, typstrs, test.want)
		}
	}
}
Beispiel #5
0
func TestObjValueLookup(t *testing.T) {
	conf := loader.Config{ParserMode: parser.ParseComments}
	f, err := conf.ParseFile("testdata/objlookup.go", nil)
	if err != nil {
		t.Error(err)
		return
	}
	conf.CreateFromFiles("main", f)

	// Maps each var Ident (represented "name:linenum") to the
	// kind of ssa.Value we expect (represented "Constant", "&Alloc").
	expectations := make(map[string]string)

	// Find all annotations of form x::BinOp, &y::Alloc, etc.
	re := regexp.MustCompile(`(\b|&)?(\w*)::(\w*)\b`)
	for _, c := range f.Comments {
		text := c.Text()
		pos := conf.Fset.Position(c.Pos())
		for _, m := range re.FindAllStringSubmatch(text, -1) {
			key := fmt.Sprintf("%s:%d", m[2], pos.Line)
			value := m[1] + m[3]
			expectations[key] = value
		}
	}

	iprog, err := conf.Load()
	if err != nil {
		t.Error(err)
		return
	}

	prog := ssa.Create(iprog, 0 /*|ssa.LogFunctions*/)
	mainInfo := iprog.Created[0]
	mainPkg := prog.Package(mainInfo.Pkg)
	mainPkg.SetDebugMode(true)
	mainPkg.Build()

	var varIds []*ast.Ident
	var varObjs []*types.Var
	for id, obj := range mainInfo.Defs {
		// Check invariants for func and const objects.
		switch obj := obj.(type) {
		case *types.Func:
			checkFuncValue(t, prog, obj)

		case *types.Const:
			checkConstValue(t, prog, obj)

		case *types.Var:
			if id.Name == "_" {
				continue
			}
			varIds = append(varIds, id)
			varObjs = append(varObjs, obj)
		}
	}
	for id, obj := range mainInfo.Uses {
		if obj, ok := obj.(*types.Var); ok {
			varIds = append(varIds, id)
			varObjs = append(varObjs, obj)
		}
	}

	// Check invariants for var objects.
	// The result varies based on the specific Ident.
	for i, id := range varIds {
		obj := varObjs[i]
		ref, _ := astutil.PathEnclosingInterval(f, id.Pos(), id.Pos())
		pos := prog.Fset.Position(id.Pos())
		exp := expectations[fmt.Sprintf("%s:%d", id.Name, pos.Line)]
		if exp == "" {
			t.Errorf("%s: no expectation for var ident %s ", pos, id.Name)
			continue
		}
		wantAddr := false
		if exp[0] == '&' {
			wantAddr = true
			exp = exp[1:]
		}
		checkVarValue(t, prog, mainPkg, ref, obj, exp, wantAddr)
	}
}
Beispiel #6
0
// Ensure that, in debug mode, we can determine the ssa.Value
// corresponding to every ast.Expr.
func TestValueForExpr(t *testing.T) {
	conf := loader.Config{ParserMode: parser.ParseComments}
	f, err := conf.ParseFile("testdata/valueforexpr.go", nil)
	if err != nil {
		t.Error(err)
		return
	}
	conf.CreateFromFiles("main", f)

	iprog, err := conf.Load()
	if err != nil {
		t.Error(err)
		return
	}

	mainInfo := iprog.Created[0]

	prog := ssa.Create(iprog, 0)
	mainPkg := prog.Package(mainInfo.Pkg)
	mainPkg.SetDebugMode(true)
	mainPkg.Build()

	if false {
		// debugging
		for _, mem := range mainPkg.Members {
			if fn, ok := mem.(*ssa.Function); ok {
				fn.WriteTo(os.Stderr)
			}
		}
	}

	// Find the actual AST node for each canonical position.
	parenExprByPos := make(map[token.Pos]*ast.ParenExpr)
	ast.Inspect(f, func(n ast.Node) bool {
		if n != nil {
			if e, ok := n.(*ast.ParenExpr); ok {
				parenExprByPos[e.Pos()] = e
			}
		}
		return true
	})

	// Find all annotations of form /*@kind*/.
	for _, c := range f.Comments {
		text := strings.TrimSpace(c.Text())
		if text == "" || text[0] != '@' {
			continue
		}
		text = text[1:]
		pos := c.End() + 1
		position := prog.Fset.Position(pos)
		var e ast.Expr
		if target := parenExprByPos[pos]; target == nil {
			t.Errorf("%s: annotation doesn't precede ParenExpr: %q", position, text)
			continue
		} else {
			e = target.X
		}

		path, _ := astutil.PathEnclosingInterval(f, pos, pos)
		if path == nil {
			t.Errorf("%s: can't find AST path from root to comment: %s", position, text)
			continue
		}

		fn := ssa.EnclosingFunction(mainPkg, path)
		if fn == nil {
			t.Errorf("%s: can't find enclosing function", position)
			continue
		}

		v, gotAddr := fn.ValueForExpr(e) // (may be nil)
		got := strings.TrimPrefix(fmt.Sprintf("%T", v), "*ssa.")
		if want := text; got != want {
			t.Errorf("%s: got value %q, want %q", position, got, want)
		}
		if v != nil {
			T := v.Type()
			if gotAddr {
				T = T.Underlying().(*types.Pointer).Elem() // deref
			}
			if !types.Identical(T, mainInfo.TypeOf(e)) {
				t.Errorf("%s: got type %s, want %s", position, mainInfo.TypeOf(e), T)
			}
		}
	}
}
Beispiel #7
0
func doOneInput(input, filename string) bool {
	conf := loader.Config{SourceImports: true}

	// Parsing.
	f, err := conf.ParseFile(filename, input)
	if err != nil {
		fmt.Println(err)
		return false
	}

	// Create single-file main package and import its dependencies.
	conf.CreateFromFiles("main", f)
	iprog, err := conf.Load()
	if err != nil {
		fmt.Println(err)
		return false
	}
	mainPkgInfo := iprog.Created[0].Pkg

	// SSA creation + building.
	prog := ssa.Create(iprog, ssa.SanityCheckFunctions)
	prog.BuildAll()

	mainpkg := prog.Package(mainPkgInfo)
	ptrmain := mainpkg // main package for the pointer analysis
	if mainpkg.Func("main") == nil {
		// No main function; assume it's a test.
		ptrmain = prog.CreateTestMainPackage(mainpkg)
	}

	// Find all calls to the built-in print(x).  Analytically,
	// print is a no-op, but it's a convenient hook for testing
	// the PTS of an expression, so our tests use it.
	probes := make(map[*ssa.CallCommon]bool)
	for fn := range ssautil.AllFunctions(prog) {
		if fn.Pkg == mainpkg {
			for _, b := range fn.Blocks {
				for _, instr := range b.Instrs {
					if instr, ok := instr.(ssa.CallInstruction); ok {
						if b, ok := instr.Common().Value.(*ssa.Builtin); ok && b.Name() == "print" {
							probes[instr.Common()] = true
						}
					}
				}
			}
		}
	}

	ok := true

	lineMapping := make(map[string]string) // maps "file:line" to @line tag

	// Parse expectations in this input.
	var exps []*expectation
	re := regexp.MustCompile("// *@([a-z]*) *(.*)$")
	lines := strings.Split(input, "\n")
	for linenum, line := range lines {
		linenum++ // make it 1-based
		if matches := re.FindAllStringSubmatch(line, -1); matches != nil {
			match := matches[0]
			kind, rest := match[1], match[2]
			e := &expectation{kind: kind, filename: filename, linenum: linenum}

			if kind == "line" {
				if rest == "" {
					ok = false
					e.errorf("@%s expectation requires identifier", kind)
				} else {
					lineMapping[fmt.Sprintf("%s:%d", filename, linenum)] = rest
				}
				continue
			}

			if e.needsProbe() && !strings.Contains(line, "print(") {
				ok = false
				e.errorf("@%s expectation must follow call to print(x)", kind)
				continue
			}

			switch kind {
			case "pointsto":
				e.args = split(rest, "|")

			case "types":
				for _, typstr := range split(rest, "|") {
					var t types.Type = types.Typ[types.Invalid] // means "..."
					if typstr != "..." {
						texpr, err := parser.ParseExpr(typstr)
						if err != nil {
							ok = false
							// Don't print err since its location is bad.
							e.errorf("'%s' is not a valid type", typstr)
							continue
						}
						mainFileScope := mainpkg.Object.Scope().Child(0)
						t, _, err = types.EvalNode(prog.Fset, texpr, mainpkg.Object, mainFileScope)
						if err != nil {
							ok = false
							// Don't print err since its location is bad.
							e.errorf("'%s' is not a valid type: %s", typstr, err)
							continue
						}
					}
					e.types = append(e.types, t)
				}

			case "calls":
				e.args = split(rest, "->")
				// TODO(adonovan): eagerly reject the
				// expectation if fn doesn't denote
				// existing function, rather than fail
				// the expectation after analysis.
				if len(e.args) != 2 {
					ok = false
					e.errorf("@calls expectation wants 'caller -> callee' arguments")
					continue
				}

			case "warning":
				lit, err := strconv.Unquote(strings.TrimSpace(rest))
				if err != nil {
					ok = false
					e.errorf("couldn't parse @warning operand: %s", err.Error())
					continue
				}
				e.args = append(e.args, lit)

			default:
				ok = false
				e.errorf("unknown expectation kind: %s", e)
				continue
			}
			exps = append(exps, e)
		}
	}

	var log bytes.Buffer
	fmt.Fprintf(&log, "Input: %s\n", filename)

	// Run the analysis.
	config := &pointer.Config{
		Reflection:     true,
		BuildCallGraph: true,
		Mains:          []*ssa.Package{ptrmain},
		Log:            &log,
	}
	for probe := range probes {
		v := probe.Args[0]
		if pointer.CanPoint(v.Type()) {
			config.AddQuery(v)
		}
	}

	// Print the log is there was an error or a panic.
	complete := false
	defer func() {
		if !complete || !ok {
			log.WriteTo(os.Stderr)
		}
	}()

	result, err := pointer.Analyze(config)
	if err != nil {
		panic(err) // internal error in pointer analysis
	}

	// Check the expectations.
	for _, e := range exps {
		var call *ssa.CallCommon
		var pts pointer.PointsToSet
		var tProbe types.Type
		if e.needsProbe() {
			if call, pts = findProbe(prog, probes, result.Queries, e); call == nil {
				ok = false
				e.errorf("unreachable print() statement has expectation %s", e)
				continue
			}
			tProbe = call.Args[0].Type()
			if !pointer.CanPoint(tProbe) {
				ok = false
				e.errorf("expectation on non-pointerlike operand: %s", tProbe)
				continue
			}
		}

		switch e.kind {
		case "pointsto":
			if !checkPointsToExpectation(e, pts, lineMapping, prog) {
				ok = false
			}

		case "types":
			if !checkTypesExpectation(e, pts, tProbe) {
				ok = false
			}

		case "calls":
			if !checkCallsExpectation(prog, e, result.CallGraph) {
				ok = false
			}

		case "warning":
			if !checkWarningExpectation(prog, e, result.Warnings) {
				ok = false
			}
		}
	}

	complete = true

	// ok = false // debugging: uncomment to always see log

	return ok
}
Beispiel #8
0
// Tests that synthesized init functions are correctly formed.
// Bare init functions omit calls to dependent init functions and the use of
// an init guard. They are useful in cases where the client uses a different
// calling convention for init functions, or cases where it is easier for a
// client to analyze bare init functions. Both of these aspects are used by
// the llgo compiler for simpler integration with gccgo's runtime library,
// and to simplify the analysis whereby it deduces which stores to globals
// can be lowered to global initializers.
func TestInit(t *testing.T) {
	tests := []struct {
		mode        ssa.BuilderMode
		input, want string
	}{
		{0, `package A; import _ "errors"; var i int = 42`,
			`# Name: A.init
# Package: A
# Synthetic: package initializer
func init():
0:                                                                entry P:0 S:2
	t0 = *init$guard                                                   bool
	if t0 goto 2 else 1
1:                                                           init.start P:1 S:1
	*init$guard = true:bool
	t1 = errors.init()                                                   ()
	*i = 42:int
	jump 2
2:                                                            init.done P:2 S:0
	return

`},
		{ssa.BareInits, `package B; import _ "errors"; var i int = 42`,
			`# Name: B.init
# Package: B
# Synthetic: package initializer
func init():
0:                                                                entry P:0 S:0
	*i = 42:int
	return

`},
	}
	for _, test := range tests {
		// Create a single-file main package.
		var conf loader.Config
		f, err := conf.ParseFile("<input>", test.input)
		if err != nil {
			t.Errorf("test %q: %s", test.input[:15], err)
			continue
		}
		conf.CreateFromFiles(f.Name.Name, f)

		iprog, err := conf.Load()
		if err != nil {
			t.Errorf("test 'package %s': Load: %s", f.Name.Name, err)
			continue
		}
		prog := ssa.Create(iprog, test.mode)
		mainPkg := prog.Package(iprog.Created[0].Pkg)
		prog.BuildAll()
		initFunc := mainPkg.Func("init")
		if initFunc == nil {
			t.Errorf("test 'package %s': no init function", f.Name.Name)
			continue
		}

		var initbuf bytes.Buffer
		_, err = initFunc.WriteTo(&initbuf)
		if err != nil {
			t.Errorf("test 'package %s': WriteTo: %s", f.Name.Name, err)
			continue
		}

		if initbuf.String() != test.want {
			t.Errorf("test 'package %s': got %q, want %q", f.Name.Name, initbuf.String(), test.want)
		}
	}
}
// This program demonstrates how to use the pointer analysis to
// obtain a conservative call-graph of a Go program.
// It also shows how to compute the points-to set of a variable,
// in this case, (C).f's ch parameter.
//
func Example() {
	const myprog = `
package main

import "fmt"

type I interface {
	f(map[string]int)
}

type C struct{}

func (C) f(m map[string]int) {
	fmt.Println("C.f()")
}

func main() {
	var i I = C{}
	x := map[string]int{"one":1}
	i.f(x) // dynamic method call
}
`
	// Construct a loader.
	conf := loader.Config{SourceImports: true}

	// Parse the input file.
	file, err := conf.ParseFile("myprog.go", myprog, 0)
	if err != nil {
		fmt.Print(err) // parse error
		return
	}

	// Create single-file main package and import its dependencies.
	conf.CreateFromFiles("main", file)

	iprog, err := conf.Load()
	if err != nil {
		fmt.Print(err) // type error in some package
		return
	}

	// Create SSA-form program representation.
	prog := ssa.Create(iprog, 0)
	mainPkg := prog.Package(iprog.Created[0].Pkg)

	// Build SSA code for bodies of all functions in the whole program.
	prog.BuildAll()

	// Configure the pointer analysis to build a call-graph.
	config := &pointer.Config{
		Mains:          []*ssa.Package{mainPkg},
		BuildCallGraph: true,
	}

	// Query points-to set of (C).f's parameter m, a map.
	C := mainPkg.Type("C").Type()
	Cfm := prog.LookupMethod(C, mainPkg.Object, "f").Params[1]
	config.AddQuery(Cfm)

	// Run the pointer analysis.
	result, err := pointer.Analyze(config)
	if err != nil {
		panic(err) // internal error in pointer analysis
	}

	// Find edges originating from the main package.
	// By converting to strings, we de-duplicate nodes
	// representing the same function due to context sensitivity.
	var edges []string
	callgraph.GraphVisitEdges(result.CallGraph, func(edge *callgraph.Edge) error {
		caller := edge.Caller.Func
		if caller.Pkg == mainPkg {
			edges = append(edges, fmt.Sprint(caller, " --> ", edge.Callee.Func))
		}
		return nil
	})

	// Print the edges in sorted order.
	sort.Strings(edges)
	for _, edge := range edges {
		fmt.Println(edge)
	}
	fmt.Println()

	// Print the labels of (C).f(m)'s points-to set.
	fmt.Println("m may point to:")
	var labels []string
	for _, l := range result.Queries[Cfm].PointsTo().Labels() {
		label := fmt.Sprintf("  %s: %s", prog.Fset.Position(l.Pos()), l)
		labels = append(labels, label)
	}
	sort.Strings(labels)
	for _, label := range labels {
		fmt.Println(label)
	}

	// Output:
	// (main.C).f --> fmt.Println
	// main.init --> fmt.init
	// main.main --> (main.C).f
	//
	// m may point to:
	//   myprog.go:18:21: makemap
}
Beispiel #10
0
// This program demonstrates how to run the SSA builder on a "Hello,
// World!" program and shows the printed representation of packages,
// functions and instructions.
//
// Within the function listing, the name of each BasicBlock such as
// ".0.entry" is printed left-aligned, followed by the block's
// Instructions.
//
// For each instruction that defines an SSA virtual register
// (i.e. implements Value), the type of that value is shown in the
// right column.
//
// Build and run the ssadump.go program if you want a standalone tool
// with similar functionality. It is located at
// code.google.com/p/go.tools/cmd/ssadump.
//
func Example() {
	const hello = `
package main

import "fmt"

const message = "Hello, World!"

func main() {
	fmt.Println(message)
}
`
	var conf loader.Config

	// Parse the input file.
	file, err := conf.ParseFile("hello.go", hello)
	if err != nil {
		fmt.Print(err) // parse error
		return
	}

	// Create single-file main package.
	conf.CreateFromFiles("main", file)

	// Load the main package and its dependencies.
	iprog, err := conf.Load()
	if err != nil {
		fmt.Print(err) // type error in some package
		return
	}

	// Create SSA-form program representation.
	prog := ssa.Create(iprog, ssa.SanityCheckFunctions)
	mainPkg := prog.Package(iprog.Created[0].Pkg)

	// Print out the package.
	mainPkg.WriteTo(os.Stdout)

	// Build SSA code for bodies of functions in mainPkg.
	mainPkg.Build()

	// Print out the package-level functions.
	mainPkg.Func("init").WriteTo(os.Stdout)
	mainPkg.Func("main").WriteTo(os.Stdout)

	// Output:
	//
	// package main:
	//   func  init       func()
	//   var   init$guard bool
	//   func  main       func()
	//   const message    message = "Hello, World!":untyped string
	//
	// # Name: main.init
	// # Package: main
	// # Synthetic: package initializer
	// func init():
	// .0.entry:                                                               P:0 S:2
	// 	t0 = *init$guard                                                   bool
	// 	if t0 goto 2.init.done else 1.init.start
	// .1.init.start:                                                          P:1 S:1
	// 	*init$guard = true:bool
	// 	t1 = fmt.init()                                                      ()
	// 	jump 2.init.done
	// .2.init.done:                                                           P:2 S:0
	// 	return
	//
	// # Name: main.main
	// # Package: main
	// # Location: hello.go:8:6
	// func main():
	// .0.entry:                                                               P:0 S:0
	// 	t0 = new [1]interface{} (varargs)                       *[1]interface{}
	// 	t1 = &t0[0:int]                                            *interface{}
	// 	t2 = make interface{} <- string ("Hello, World!":string)    interface{}
	// 	*t1 = t2
	// 	t3 = slice t0[:]                                          []interface{}
	// 	t4 = fmt.Println(t3...)                              (n int, err error)
	// 	return
}