// Query runs a single oracle query.
//
// args specify the main package in (*loader.Config).FromArgs syntax.
// mode is the query mode ("callers", etc).
// ptalog is the (optional) pointer-analysis log file.
// buildContext is the go/build configuration for locating packages.
// reflection determines whether to model reflection soundly (currently slow).
//
// Clients that intend to perform multiple queries against the same
// analysis scope should use this pattern instead:
//
// conf := loader.Config{Build: buildContext}
// ... populate config, e.g. conf.FromArgs(args) ...
// iprog, err := conf.Load()
// if err != nil { ... }
// o, err := oracle.New(iprog, nil, false)
// if err != nil { ... }
// for ... {
// qpos, err := oracle.ParseQueryPos(imp, pos, needExact)
// if err != nil { ... }
//
// res, err := o.Query(mode, qpos)
// if err != nil { ... }
//
// // use res
// }
//
// TODO(adonovan): the ideal 'needsExact' parameter for ParseQueryPos
// depends on the query mode; how should we expose this?
//
func Query(args []string, mode, pos string, ptalog io.Writer, buildContext *build.Context, reflection bool) (*Result, error) {
if mode == "what" {
// Bypass package loading, type checking, SSA construction.
return what(pos, buildContext)
}
minfo := findMode(mode)
if minfo == nil {
return nil, fmt.Errorf("invalid mode type: %q", mode)
}
conf := loader.Config{Build: buildContext}
// Determine initial packages.
args, err := conf.FromArgs(args, true)
if err != nil {
return nil, err
}
if len(args) > 0 {
return nil, fmt.Errorf("surplus arguments: %q", args)
}
// For queries needing only a single typed package,
// reduce the analysis scope to that package.
if minfo.needs&(needSSA|needRetainTypeInfo) == 0 {
reduceScope(pos, &conf)
}
// TODO(adonovan): report type errors to the user via Serial
// types, not stderr?
// conf.TypeChecker.Error = func(err error) {
// E := err.(types.Error)
// fmt.Fprintf(os.Stderr, "%s: %s\n", E.Fset.Position(E.Pos), E.Msg)
// }
// Load/parse/type-check the program.
iprog, err := conf.Load()
if err != nil {
return nil, err
}
o, err := newOracle(iprog, ptalog, minfo.needs, reflection)
if err != nil {
return nil, err
}
qpos, err := ParseQueryPos(iprog, pos, minfo.needs&needExactPos != 0)
if err != nil && minfo.needs&(needPos|needExactPos) != 0 {
return nil, err
}
// SSA is built and we have the QueryPos.
// Release the other ASTs and type info to the GC.
iprog = nil
return o.query(minfo, qpos)
}
// Run runs program analysis and computes the resulting markup,
// populating *result in a thread-safe manner, first with type
// information then later with pointer analysis information if
// enabled by the pta flag.
//
func Run(pta bool, result *Result) {
conf := loader.Config{
AllowErrors: true,
}
// Silence the default error handler.
// Don't print all errors; we'll report just
// one per errant package later.
conf.TypeChecker.Error = func(e error) {}
var roots, args []string // roots[i] ends with os.PathSeparator
// Enumerate packages in $GOROOT.
root := filepath.Join(runtime.GOROOT(), "src") + string(os.PathSeparator)
roots = append(roots, root)
args = allPackages(root)
log.Printf("GOROOT=%s: %s\n", root, args)
// Enumerate packages in $GOPATH.
for i, dir := range filepath.SplitList(build.Default.GOPATH) {
root := filepath.Join(dir, "src") + string(os.PathSeparator)
roots = append(roots, root)
pkgs := allPackages(root)
log.Printf("GOPATH[%d]=%s: %s\n", i, root, pkgs)
args = append(args, pkgs...)
}
// Uncomment to make startup quicker during debugging.
//args = []string{"github.com/fzipp/pythia/internal/tools/cmd/godoc"}
//args = []string{"fmt"}
if _, err := conf.FromArgs(args, true); err != nil {
// TODO(adonovan): degrade gracefully, not fail totally.
// (The crippling case is a parse error in an external test file.)
result.setStatusf("Analysis failed: %s.", err) // import error
return
}
result.setStatusf("Loading and type-checking packages...")
iprog, err := conf.Load()
if iprog != nil {
// Report only the first error of each package.
for _, info := range iprog.AllPackages {
for _, err := range info.Errors {
fmt.Fprintln(os.Stderr, err)
break
}
}
log.Printf("Loaded %d packages.", len(iprog.AllPackages))
}
if err != nil {
result.setStatusf("Loading failed: %s.\n", err)
return
}
// Create SSA-form program representation.
// Only the transitively error-free packages are used.
prog := ssa.Create(iprog, ssa.GlobalDebug)
// Compute the set of main packages, including testmain.
allPackages := prog.AllPackages()
var mainPkgs []*ssa.Package
if testmain := prog.CreateTestMainPackage(allPackages...); testmain != nil {
mainPkgs = append(mainPkgs, testmain)
if p := testmain.Const("packages"); p != nil {
log.Printf("Tested packages: %v", exact.StringVal(p.Value.Value))
}
}
for _, pkg := range allPackages {
if pkg.Object.Name() == "main" && pkg.Func("main") != nil {
mainPkgs = append(mainPkgs, pkg)
}
}
log.Print("Transitively error-free main packages: ", mainPkgs)
// Build SSA code for bodies of all functions in the whole program.
result.setStatusf("Constructing SSA form...")
prog.BuildAll()
log.Print("SSA construction complete")
a := analysis{
result: result,
prog: prog,
pcgs: make(map[*ssa.Package]*packageCallGraph),
}
// Build a mapping from openable filenames to godoc file URLs,
// i.e. "/src/" plus path relative to GOROOT/src or GOPATH[i]/src.
a.path2url = make(map[string]string)
for _, info := range iprog.AllPackages {
nextfile:
for _, f := range info.Files {
if f.Pos() == 0 {
continue // e.g. files generated by cgo
}
abs := iprog.Fset.File(f.Pos()).Name()
// Find the root to which this file belongs.
for _, root := range roots {
rel := strings.TrimPrefix(abs, root)
if len(rel) < len(abs) {
a.path2url[abs] = "/src/" + filepath.ToSlash(rel)
continue nextfile
}
}
log.Printf("Can't locate file %s (package %q) beneath any root",
abs, info.Pkg.Path())
}
}
// Add links for scanner, parser, type-checker errors.
// TODO(adonovan): fix: these links can overlap with
// identifier markup, causing the renderer to emit some
// characters twice.
errors := make(map[token.Position][]string)
for _, info := range iprog.AllPackages {
for _, err := range info.Errors {
switch err := err.(type) {
case types.Error:
posn := a.prog.Fset.Position(err.Pos)
errors[posn] = append(errors[posn], err.Msg)
case scanner.ErrorList:
for _, e := range err {
errors[e.Pos] = append(errors[e.Pos], e.Msg)
}
default:
log.Printf("Package %q has error (%T) without position: %v\n",
info.Pkg.Path(), err, err)
}
}
}
for posn, errs := range errors {
fi, offset := a.fileAndOffsetPosn(posn)
fi.addLink(errorLink{
start: offset,
msg: strings.Join(errs, "\n"),
})
}
// ---------- type-based analyses ----------
// Compute the all-pairs IMPLEMENTS relation.
// Collect all named types, even local types
// (which can have methods via promotion)
// and the built-in "error".
errorType := types.Universe.Lookup("error").Type().(*types.Named)
a.allNamed = append(a.allNamed, errorType)
for _, info := range iprog.AllPackages {
for _, obj := range info.Defs {
if obj, ok := obj.(*types.TypeName); ok {
a.allNamed = append(a.allNamed, obj.Type().(*types.Named))
}
}
}
log.Print("Computing implements relation...")
facts := computeImplements(&a.prog.MethodSets, a.allNamed)
// Add the type-based analysis results.
log.Print("Extracting type info...")
for _, info := range iprog.AllPackages {
a.doTypeInfo(info, facts)
}
a.visitInstrs(pta)
result.setStatusf("Type analysis complete.")
if pta {
a.pointer(mainPkgs)
}
}
func TestStdlib(t *testing.T) {
// Load, parse and type-check the program.
t0 := time.Now()
alloc0 := bytesAllocated()
// Load, parse and type-check the program.
ctxt := build.Default // copy
ctxt.GOPATH = "" // disable GOPATH
conf := loader.Config{Build: &ctxt}
if _, err := conf.FromArgs(buildutil.AllPackages(conf.Build), true); err != nil {
t.Errorf("FromArgs failed: %v", err)
return
}
iprog, err := conf.Load()
if err != nil {
t.Fatalf("Load failed: %v", err)
}
t1 := time.Now()
alloc1 := bytesAllocated()
// Create SSA packages.
var mode ssa.BuilderMode
// Comment out these lines during benchmarking. Approx SSA build costs are noted.
mode |= ssa.SanityCheckFunctions // + 2% space, + 4% time
mode |= ssa.GlobalDebug // +30% space, +18% time
prog := ssa.Create(iprog, mode)
t2 := time.Now()
// Build SSA.
prog.BuildAll()
t3 := time.Now()
alloc3 := bytesAllocated()
numPkgs := len(prog.AllPackages())
if want := 140; numPkgs < want {
t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
}
// Keep iprog reachable until after we've measured memory usage.
if len(iprog.AllPackages) == 0 {
print() // unreachable
}
allFuncs := ssautil.AllFunctions(prog)
// Check that all non-synthetic functions have distinct names.
// Synthetic wrappers for exported methods should be distinct too,
// except for unexported ones (explained at (*Function).RelString).
byName := make(map[string]*ssa.Function)
for fn := range allFuncs {
if fn.Synthetic == "" || ast.IsExported(fn.Name()) {
str := fn.String()
prev := byName[str]
byName[str] = fn
if prev != nil {
t.Errorf("%s: duplicate function named %s",
prog.Fset.Position(fn.Pos()), str)
t.Errorf("%s: (previously defined here)",
prog.Fset.Position(prev.Pos()))
}
}
}
// Dump some statistics.
var numInstrs int
for fn := range allFuncs {
for _, b := range fn.Blocks {
numInstrs += len(b.Instrs)
}
}
// determine line count
var lineCount int
prog.Fset.Iterate(func(f *token.File) bool {
lineCount += f.LineCount()
return true
})
// NB: when benchmarking, don't forget to clear the debug +
// sanity builder flags for better performance.
t.Log("GOMAXPROCS: ", runtime.GOMAXPROCS(0))
t.Log("#Source lines: ", lineCount)
t.Log("Load/parse/typecheck: ", t1.Sub(t0))
t.Log("SSA create: ", t2.Sub(t1))
t.Log("SSA build: ", t3.Sub(t2))
// SSA stats:
t.Log("#Packages: ", numPkgs)
t.Log("#Functions: ", len(allFuncs))
t.Log("#Instructions: ", numInstrs)
t.Log("#MB AST+types: ", int64(alloc1-alloc0)/1e6)
t.Log("#MB SSA: ", int64(alloc3-alloc1)/1e6)
}
func TestStdlib(t *testing.T) {
if !*runStdlibTest {
t.Skip("skipping (slow) stdlib test (use --stdlib)")
}
// Load, parse and type-check the program.
ctxt := build.Default // copy
ctxt.GOPATH = "" // disable GOPATH
conf := loader.Config{Build: &ctxt}
if _, err := conf.FromArgs(buildutil.AllPackages(conf.Build), true); err != nil {
t.Errorf("FromArgs failed: %v", err)
return
}
iprog, err := conf.Load()
if err != nil {
t.Fatalf("Load failed: %v", err)
}
// Create SSA packages.
prog := ssa.Create(iprog, 0)
prog.BuildAll()
numPkgs := len(prog.AllPackages())
if want := 240; numPkgs < want {
t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
}
// Determine the set of packages/tests to analyze.
var testPkgs []*ssa.Package
for _, info := range iprog.InitialPackages() {
testPkgs = append(testPkgs, prog.Package(info.Pkg))
}
testmain := prog.CreateTestMainPackage(testPkgs...)
if testmain == nil {
t.Fatal("analysis scope has tests")
}
// Run the analysis.
config := &Config{
Reflection: false, // TODO(adonovan): fix remaining bug in rVCallConstraint, then enable.
BuildCallGraph: true,
Mains: []*ssa.Package{testmain},
}
// TODO(adonovan): add some query values (affects track bits).
t0 := time.Now()
result, err := Analyze(config)
if err != nil {
t.Fatal(err) // internal error in pointer analysis
}
_ = result // TODO(adonovan): measure something
t1 := time.Now()
// Dump some statistics.
allFuncs := ssautil.AllFunctions(prog)
var numInstrs int
for fn := range allFuncs {
for _, b := range fn.Blocks {
numInstrs += len(b.Instrs)
}
}
// determine line count
var lineCount int
prog.Fset.Iterate(func(f *token.File) bool {
lineCount += f.LineCount()
return true
})
t.Log("#Source lines: ", lineCount)
t.Log("#Instructions: ", numInstrs)
t.Log("Pointer analysis: ", t1.Sub(t0))
}
func run(t *testing.T, dir, input string, success successPredicate) bool {
fmt.Printf("Input: %s\n", input)
start := time.Now()
var inputs []string
for _, i := range strings.Split(input, " ") {
if strings.HasSuffix(i, ".go") {
i = dir + i
}
inputs = append(inputs, i)
}
var conf loader.Config
if _, err := conf.FromArgs(inputs, true); err != nil {
t.Errorf("FromArgs(%s) failed: %s", inputs, err)
return false
}
conf.Import("runtime")
// Print a helpful hint if we don't make it to the end.
var hint string
defer func() {
if hint != "" {
fmt.Println("FAIL")
fmt.Println(hint)
} else {
fmt.Println("PASS")
}
interp.CapturedOutput = nil
}()
hint = fmt.Sprintf("To dump SSA representation, run:\n%% go build golang.org/x/tools/cmd/ssadump && ./ssadump -build=CFP %s\n", input)
iprog, err := conf.Load()
if err != nil {
t.Errorf("conf.Load(%s) failed: %s", inputs, err)
return false
}
prog := ssa.Create(iprog, ssa.SanityCheckFunctions)
prog.BuildAll()
var mainPkg *ssa.Package
var initialPkgs []*ssa.Package
for _, info := range iprog.InitialPackages() {
if info.Pkg.Path() == "runtime" {
continue // not an initial package
}
p := prog.Package(info.Pkg)
initialPkgs = append(initialPkgs, p)
if mainPkg == nil && p.Func("main") != nil {
mainPkg = p
}
}
if mainPkg == nil {
testmainPkg := prog.CreateTestMainPackage(initialPkgs...)
if testmainPkg == nil {
t.Errorf("CreateTestMainPackage(%s) returned nil", mainPkg)
return false
}
if testmainPkg.Func("main") == nil {
t.Errorf("synthetic testmain package has no main")
return false
}
mainPkg = testmainPkg
}
var out bytes.Buffer
interp.CapturedOutput = &out
hint = fmt.Sprintf("To trace execution, run:\n%% go build golang.org/x/tools/cmd/ssadump && ./ssadump -build=C -run --interp=T %s\n", input)
exitCode := interp.Interpret(mainPkg, 0, &types.StdSizes{8, 8}, inputs[0], []string{})
// The definition of success varies with each file.
if err := success(exitCode, out.String()); err != nil {
t.Errorf("interp.Interpret(%s) failed: %s", inputs, err)
return false
}
hint = "" // call off the hounds
if false {
fmt.Println(input, time.Since(start)) // test profiling
}
return true
}
