reflect: add support for DeepEqual

The implementation has been mostly copied from the Go reference
implementation with some small changes to fit TinyGo.

Source: https://github.com/golang/go/blob/77a11c05d6a6f766c75f804ea9b8796f9a9f85a3/src/reflect/deepequal.go

In addition, this commit also contains the following:

  - A set of tests copied from the Go reflect package.
  - An increased stack size for the riscv-qemu and hifive1-qemu targets
    (because they otherwise fail to run the tests). Because these
    targets are only used for testing, this seems fine to me.

src/reflect/all_test.go

@@ -0,0 +1,188 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package reflect_test
+
+import (
+	"math"
+	. "reflect"
+	"testing"
+)
+
+type Basic struct {
+	x int
+	y float32
+}
+
+type NotBasic Basic
+
+type DeepEqualTest struct {
+	a, b interface{}
+	eq   bool
+}
+
+// Simple functions for DeepEqual tests.
+var (
+	fn1 func()             // nil.
+	fn2 func()             // nil.
+	fn3 = func() { fn1() } // Not nil.
+)
+
+type self struct{}
+
+type Loopy interface{}
+
+var loopy1, loopy2 Loopy
+var cycleMap1, cycleMap2, cycleMap3 map[string]interface{}
+
+type structWithSelfPtr struct {
+	p *structWithSelfPtr
+	s string
+}
+
+func init() {
+	loopy1 = &loopy2
+	loopy2 = &loopy1
+
+	cycleMap1 = map[string]interface{}{}
+	cycleMap1["cycle"] = cycleMap1
+	cycleMap2 = map[string]interface{}{}
+	cycleMap2["cycle"] = cycleMap2
+	cycleMap3 = map[string]interface{}{}
+	cycleMap3["different"] = cycleMap3
+}
+
+// Note: all tests involving maps have been commented out because they aren't
+// supported yet.
+var deepEqualTests = []DeepEqualTest{
+	// Equalities
+	{nil, nil, true},
+	{1, 1, true},
+	{int32(1), int32(1), true},
+	{0.5, 0.5, true},
+	{float32(0.5), float32(0.5), true},
+	{"hello", "hello", true},
+	{make([]int, 10), make([]int, 10), true},
+	{&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true},
+	{Basic{1, 0.5}, Basic{1, 0.5}, true},
+	{error(nil), error(nil), true},
+	//{map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true},
+	{fn1, fn2, true},
+	{[]byte{1, 2, 3}, []byte{1, 2, 3}, true},
+	{[]MyByte{1, 2, 3}, []MyByte{1, 2, 3}, true},
+	{MyBytes{1, 2, 3}, MyBytes{1, 2, 3}, true},
+
+	// Inequalities
+	{1, 2, false},
+	{int32(1), int32(2), false},
+	{0.5, 0.6, false},
+	{float32(0.5), float32(0.6), false},
+	{"hello", "hey", false},
+	{make([]int, 10), make([]int, 11), false},
+	{&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false},
+	{Basic{1, 0.5}, Basic{1, 0.6}, false},
+	{Basic{1, 0}, Basic{2, 0}, false},
+	//{map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false},
+	//{map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false},
+	//{map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false},
+	//{map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false},
+	{nil, 1, false},
+	{1, nil, false},
+	{fn1, fn3, false},
+	{fn3, fn3, false},
+	{[][]int{{1}}, [][]int{{2}}, false},
+	{&structWithSelfPtr{p: &structWithSelfPtr{s: "a"}}, &structWithSelfPtr{p: &structWithSelfPtr{s: "b"}}, false},
+
+	// Fun with floating point.
+	{math.NaN(), math.NaN(), false},
+	{&[1]float64{math.NaN()}, &[1]float64{math.NaN()}, false},
+	{&[1]float64{math.NaN()}, self{}, true},
+	{[]float64{math.NaN()}, []float64{math.NaN()}, false},
+	{[]float64{math.NaN()}, self{}, true},
+	//{map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false},
+	//{map[float64]float64{math.NaN(): 1}, self{}, true},
+
+	// Nil vs empty: not the same.
+	{[]int{}, []int(nil), false},
+	{[]int{}, []int{}, true},
+	{[]int(nil), []int(nil), true},
+	//{map[int]int{}, map[int]int(nil), false},
+	//{map[int]int{}, map[int]int{}, true},
+	//{map[int]int(nil), map[int]int(nil), true},
+
+	// Mismatched types
+	{1, 1.0, false},
+	{int32(1), int64(1), false},
+	{0.5, "hello", false},
+	{[]int{1, 2, 3}, [3]int{1, 2, 3}, false},
+	{&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false},
+	{Basic{1, 0.5}, NotBasic{1, 0.5}, false},
+	{map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false},
+	{[]byte{1, 2, 3}, []MyByte{1, 2, 3}, false},
+	{[]MyByte{1, 2, 3}, MyBytes{1, 2, 3}, false},
+	{[]byte{1, 2, 3}, MyBytes{1, 2, 3}, false},
+
+	// Possible loops.
+	{&loopy1, &loopy1, true},
+	{&loopy1, &loopy2, true},
+	//{&cycleMap1, &cycleMap2, true},
+	{&cycleMap1, &cycleMap3, false},
+}
+
+func TestDeepEqual(t *testing.T) {
+	for _, test := range deepEqualTests {
+		if test.b == (self{}) {
+			test.b = test.a
+		}
+		if r := DeepEqual(test.a, test.b); r != test.eq {
+			t.Errorf("DeepEqual(%#v, %#v) = %v, want %v", test.a, test.b, r, test.eq)
+		}
+	}
+}
+
+type Recursive struct {
+	x int
+	r *Recursive
+}
+
+func TestDeepEqualRecursiveStruct(t *testing.T) {
+	a, b := new(Recursive), new(Recursive)
+	*a = Recursive{12, a}
+	*b = Recursive{12, b}
+	if !DeepEqual(a, b) {
+		t.Error("DeepEqual(recursive same) = false, want true")
+	}
+}
+
+type _Complex struct {
+	a int
+	b [3]*_Complex
+	c *string
+	d map[float64]float64
+}
+
+func TestDeepEqualComplexStruct(t *testing.T) {
+	m := make(map[float64]float64)
+	stra, strb := "hello", "hello"
+	a, b := new(_Complex), new(_Complex)
+	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
+	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
+	if !DeepEqual(a, b) {
+		t.Error("DeepEqual(complex same) = false, want true")
+	}
+}
+
+func TestDeepEqualComplexStructInequality(t *testing.T) {
+	m := make(map[float64]float64)
+	stra, strb := "hello", "helloo" // Difference is here
+	a, b := new(_Complex), new(_Complex)
+	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
+	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
+	if DeepEqual(a, b) {
+		t.Error("DeepEqual(complex different) = true, want false")
+	}
+}
+
+type MyBytes []byte
+type MyByte byte