func TestCgoOption(t *testing.T) {
switch runtime.GOOS {
// On these systems, the net and os/user packages don't use cgo.
case "plan9", "solaris", "windows":
return
}
// In nocgo builds (e.g. linux-amd64-nocgo),
// there is no "runtime/cgo" package,
// so cgo-generated Go files will have a failing import.
if !build.Default.CgoEnabled {
return
}
// Test that we can load cgo-using packages with
// CGO_ENABLED=[01], which causes go/build to select pure
// Go/native implementations, respectively, based on build
// tags.
//
// Each entry specifies a package-level object and the generic
// file expected to define it when cgo is disabled.
// When cgo is enabled, the exact file is not specified (since
// it varies by platform), but must differ from the generic one.
//
// The test also loads the actual file to verify that the
// object is indeed defined at that location.
for _, test := range []struct {
pkg, name, genericFile string
}{
{"net", "cgoLookupHost", "cgo_stub.go"},
{"os/user", "lookupId", "lookup_stubs.go"},
} {
ctxt := build.Default
for _, ctxt.CgoEnabled = range []bool{false, true} {
conf := loader.Config{Build: &ctxt}
conf.Import(test.pkg)
prog, err := conf.Load()
if err != nil {
t.Errorf("Load failed: %v", err)
continue
}
info := prog.Imported[test.pkg]
if info == nil {
t.Errorf("package %s not found", test.pkg)
continue
}
obj := info.Pkg.Scope().Lookup(test.name)
if obj == nil {
t.Errorf("no object %s.%s", test.pkg, test.name)
continue
}
posn := prog.Fset.Position(obj.Pos())
t.Logf("%s: %s (CgoEnabled=%t)", posn, obj, ctxt.CgoEnabled)
gotFile := filepath.Base(posn.Filename)
filesMatch := gotFile == test.genericFile
if ctxt.CgoEnabled && filesMatch {
t.Errorf("CGO_ENABLED=1: %s found in %s, want native file",
obj, gotFile)
} else if !ctxt.CgoEnabled && !filesMatch {
t.Errorf("CGO_ENABLED=0: %s found in %s, want %s",
obj, gotFile, test.genericFile)
}
// Load the file and check the object is declared at the right place.
b, err := ioutil.ReadFile(posn.Filename)
if err != nil {
t.Errorf("can't read %s: %s", posn.Filename, err)
continue
}
line := string(bytes.Split(b, []byte("\n"))[posn.Line-1])
ident := line[posn.Column-1:]
if !strings.HasPrefix(ident, test.name) {
t.Errorf("%s: %s not declared here (looking at %q)", posn, obj, ident)
}
}
}
}
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
}