garble/testdata/script/reflect.txtar

garble build
exec ./main
cmp stdout main.stdout

! binsubstr main$exe 'garble_main.go' 'test/main' 'importedpkg.' 'DownstreamObfuscated' 'SiblingObfuscated' 'IndirectObfuscated' 'IndirectNamedWithoutReflect' 'AliasIndirectNamedWithReflect' 'AliasIndirectNamedWithoutReflect' 'FmtTypeField'
binsubstr main$exe 'ReflectInDefined' 'ExportedField2' 'unexportedField2' 'IndirectUnobfuscated' 'IndirectNamedWithReflect'

[short] stop # no need to verify this with -short

# Check that the program works as expected without garble.
go build
exec ./main
cmp stdout main.stdout
-- go.mod --
module test/main

go 1.19
-- garble_main.go --
package main

import (
	"encoding/json"
	"fmt"
	"os"
	"reflect"
	"strings"
	"text/template"

	"test/main/importedpkg"
	"test/main/importedpkg2"
)

var Sink interface{}

func main() {
	// Fields still work fine when they are not obfuscated.
	fmt.Println(importedpkg.ReflectInDefinedVar.ExportedField2)
	fmt.Println(importedpkg.ReflectInDefined{ExportedField2: 5})

	// Type names are not obfuscated either, when reflection is used.
	printfWithoutPackage("%T\n", importedpkg.ReflectTypeOf(2))
	printfWithoutPackage("%T\n", importedpkg.ReflectTypeOfIndirect(4))

	// More complex use of reflect.
	v := importedpkg.ReflectValueOfVar
	printfWithoutPackage("%#v\n", v)
	method := reflect.ValueOf(&v).MethodByName("ExportedMethodName")
	if method.IsValid() {
		fmt.Println(method.Call(nil))
	} else {
		fmt.Println("method not found")
	}

	// Use of a common library using reflect, encoding/json.
	enc, _ := json.Marshal(EncodingT{Foo: 3})
	fmt.Println(string(enc))

	// Another common library, text/template.
	tmpl := template.Must(template.New("").Parse("Hello {{.Name}}."))
	_ = tmpl.Execute(os.Stdout, struct{Name string}{Name: "Dave"})
	fmt.Println() // Always print a newline.

	// Another complex case, involving embedding and another package.
	outer := &importedpkg.EmbeddingOuter{}
	outer.InnerField = 3
	enc, _ = json.Marshal(outer)
	fmt.Println(string(enc))

	// An edge case; the struct type is defined in a different package.
	// Note that the struct type is unnamed, but it still has named fields.
	// We only use reflection on it here, not the declaring package.
	// As such, we should obfuscate the field name.
	// Simply using the field name here used to cause build failures.
	_ = reflect.TypeOf(importedpkg.UnnamedWithDownstreamReflect{})
	fmt.Printf("%v\n", importedpkg.UnnamedWithDownstreamReflect{
		DownstreamObfuscated: "downstream",
	})

	// An edge case; the struct type is defined in package importedpkg2.
	// importedpkg2 does not use reflection on it, so it's not obfuscated there.
	// importedpkg uses reflection on a type containing ReflectInSiblingImport.
	// If our logic is incorrect, we might inconsistently obfuscate the type.
	// We should not obfuscate it when building any package.
	fmt.Printf("%v\n", importedpkg2.ReflectInSiblingImport{
		SiblingObfuscated: "sibling",
	})

	// Using type aliases as both regular fields, and embedded fields.
	var emb EmbeddingIndirect
	emb.With.IndirectUnobfuscated = "indirect-with"
	emb.With.DuplicateFieldName = 3
	emb.Without.IndirectObfuscated = "indirect-without"
	emb.Without.DuplicateFieldName = 4
	fmt.Printf("%v\n", emb)
	printfWithoutPackage("%#v\n", emb.With)

	// TODO: don't obfuscate the embedded field name here
	// printfWithoutPackage("%#v\n", importedpkg.ReflectEmbeddingAlias{})

	indirectReflection(IndirectReflection{})
	fmt.Println(FmtType{})

	// Variadic functions are a bit tricky as the number of parameters is variable.
	// We want to notice indirect uses of reflection via all variadic arguments.
	_ = importedpkg.VariadicReflect(0, 1, 2, 3)
	_ = importedpkg.VariadicReflect(0)
	variadic := VariadicReflection{ReflectionField: "variadic"}
	_ = importedpkg.VariadicReflect("foo", 1, variadic, false)
	printfWithoutPackage("%#v\n", variadic)
}

type EmbeddingIndirect struct {
	// With field names, to test selectors above.
	With importedpkg.AliasIndirectNamedWithReflect
	Without importedpkg.AliasIndirectNamedWithoutReflect

	// Embedding used to crash garble, too.
	importedpkg.AliasIndirectNamedWithReflect
}

func printfWithoutPackage(format string, v any) {
	s := fmt.Sprintf(format, v)
	if _, without, found := strings.Cut(s, "."); found {
		s = without
	}
	fmt.Print(s)
}

type EncodingT struct {
	Foo int
}

type RecursiveStruct struct {
	*RecursiveStruct
	list []RecursiveStruct
}

// This could crash or hang if we don't deal with loops.
var _ = reflect.TypeOf(RecursiveStruct{})

type IndirectReflection struct {
	ReflectionField string
}

func indirectReflection(v any) {
	fmt.Println(reflect.TypeOf(v).Field(0).Name)
}

type VariadicReflection struct {
	ReflectionField string
}

type FmtType struct {
	FmtTypeField int
}

// copied from github.com/davecgh/go-spew, which reaches into reflect's internals
var _ = func() uintptr {
	field, ok := reflect.TypeOf(reflect.Value{}).FieldByName("flag")
	if !ok {
		panic("reflect.Value has no flag field")
	}
	return field.Offset
}()


-- importedpkg/imported.go --
package importedpkg

import (
	"reflect"

	"test/main/importedpkg/indirect"
	"test/main/importedpkg2"
)

type ReflectTypeOf int

var _ = reflect.TypeOf(ReflectTypeOf(0))

type ReflectTypeOfIndirect int

var _ = reflect.TypeOf(new([]*ReflectTypeOfIndirect))

type ReflectValueOf struct {
	ExportedField string

	unexportedField string
}

func (r *ReflectValueOf) ExportedMethodName() string { return "method: " + r.ExportedField }

var ReflectValueOfVar = ReflectValueOf{ExportedField: "abc"}

var _ = reflect.TypeOf(ReflectValueOfVar)

type ReflectInDefined struct {
	ExportedField2 int

	unexportedField2 int

	importedpkg2.ReflectInSiblingImport
}

var ReflectInDefinedVar = ReflectInDefined{ExportedField2: 9000}

var _ = reflect.TypeOf(ReflectInDefinedVar)

var _ = reflect.TypeOf([]*struct{EmbeddingOuter}{})

type EmbeddingOuter struct {
	EmbeddingInner
	Anon struct {
		AnonField int
	}
}

type EmbeddingInner struct {
	InnerField int
}

type UnnamedWithDownstreamReflect = struct {
	DownstreamObfuscated string
}

type (
	AliasIndirectNamedWithReflect = indirect.IndirectNamedWithReflect
	AliasIndirectNamedWithoutReflect = indirect.IndirectNamedWithoutReflect
)

var _ = reflect.TypeOf(ReflectEmbeddingAlias{})

type ReflectEmbeddingAlias struct {
	ReflectEmbeddedAlias
}

type ReflectEmbeddedAlias = ReflectEmbeddingNamed

type ReflectEmbeddingNamed struct{}

func VariadicReflect(x any, ys ...any) int {
	_ = reflect.TypeOf(x)
	_ = reflect.TypeOf(ys)

	// TODO: we likely do not notice indirect calls via a range like this.
	for _, y := range ys {
		_ = reflect.TypeOf(y)
	}

	return len(ys)
}

-- importedpkg2/imported2.go --
package importedpkg2

type ReflectInSiblingImport struct {
	SiblingObfuscated string
}

-- importedpkg/indirect/indirect.go --
package indirect

import "reflect"

var _ = reflect.TypeOf(IndirectNamedWithReflect{})

type IndirectNamedWithReflect struct {
	IndirectUnobfuscated string

	DuplicateFieldName int
}

type IndirectNamedWithoutReflect struct {
	IndirectObfuscated string

	DuplicateFieldName int
}

-- main.stdout --
9000
{5 0 {}}
ReflectTypeOf
ReflectTypeOfIndirect
ReflectValueOf{ExportedField:"abc", unexportedField:""}
[method: abc]
{"Foo":3}
Hello Dave.
{"InnerField":3,"Anon":{"AnonField":0}}
{downstream}
{sibling}
{{indirect-with 3} {indirect-without 4} { 0}}
IndirectNamedWithReflect{IndirectUnobfuscated:"indirect-with", DuplicateFieldName:3}
ReflectionField
{0}
VariadicReflection{ReflectionField:"variadic"}