src/cmd/compile/internal/gc/pgen_test.go

// Copyright 2015 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 gc

import (
	"reflect"
	"testing"
)

// Test all code paths for cmpstackvarlt.
func TestCmpstackvar(t *testing.T) {
	testdata := []struct {
		a, b Node
		lt   bool
	}{
		{
			Node{Class: PAUTO},
			Node{Class: PFUNC},
			false,
		},
		{
			Node{Class: PFUNC},
			Node{Class: PAUTO},
			true,
		},
		{
			Node{Class: PFUNC, Xoffset: 0},
			Node{Class: PFUNC, Xoffset: 10},
			true,
		},
		{
			Node{Class: PFUNC, Xoffset: 20},
			Node{Class: PFUNC, Xoffset: 10},
			false,
		},
		{
			Node{Class: PFUNC, Xoffset: 10},
			Node{Class: PFUNC, Xoffset: 10},
			false,
		},
		{
			Node{Class: PAUTO, Used: true},
			Node{Class: PAUTO, Used: false},
			true,
		},
		{
			Node{Class: PAUTO, Used: false},
			Node{Class: PAUTO, Used: true},
			false,
		},
		{
			Node{Class: PAUTO, Type: &Type{Haspointers: 1}}, // haspointers -> false
			Node{Class: PAUTO, Type: &Type{Haspointers: 2}}, // haspointers -> true
			false,
		},
		{
			Node{Class: PAUTO, Type: &Type{Haspointers: 2}}, // haspointers -> true
			Node{Class: PAUTO, Type: &Type{Haspointers: 1}}, // haspointers -> false
			true,
		},
		{
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: true}},
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: false}},
			true,
		},
		{
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: false}},
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: true}},
			false,
		},
		{
			Node{Class: PAUTO, Type: &Type{Width: 1}, Name: &Name{}},
			Node{Class: PAUTO, Type: &Type{Width: 2}, Name: &Name{}},
			false,
		},
		{
			Node{Class: PAUTO, Type: &Type{Width: 2}, Name: &Name{}},
			Node{Class: PAUTO, Type: &Type{Width: 1}, Name: &Name{}},
			true,
		},
		{
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "xyz"}},
			true,
		},
		{
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
			false,
		},
		{
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "xyz"}},
			Node{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
			false,
		},
	}
	for _, d := range testdata {
		got := cmpstackvarlt(&d.a, &d.b)
		if got != d.lt {
			t.Errorf("want %#v < %#v", d.a, d.b)
		}
	}
}

func slice2nodelist(s []*Node) *NodeList {
	var nl *NodeList
	for _, n := range s {
		nl = list(nl, n)
	}
	return nl
}

func nodelist2slice(nl *NodeList) []*Node {
	var s []*Node
	for l := nl; l != nil; l = l.Next {
		s = append(s, l.N)
	}
	return s
}

func TestListsort(t *testing.T) {
	inp := []*Node{
		{Class: PFUNC, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 0, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 10, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 20, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Used: true, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{Haspointers: 1}, Name: &Name{}, Sym: &Sym{}}, // haspointers -> false
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: true}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{Width: 1}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{Width: 2}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "xyz"}},
	}
	want := []*Node{
		{Class: PFUNC, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 0, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 10, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PFUNC, Xoffset: 20, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Used: true, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{Needzero: true}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{Width: 2}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{Width: 1}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "abc"}},
		{Class: PAUTO, Type: &Type{}, Name: &Name{}, Sym: &Sym{Name: "xyz"}},
		{Class: PAUTO, Type: &Type{Haspointers: 1}, Name: &Name{}, Sym: &Sym{}}, // haspointers -> false
	}
	// haspointers updates Type.Haspointers as a side effect, so
	// exercise this function on all inputs so that reflect.DeepEqual
	// doesn't produce false positives.
	for i := range want {
		haspointers(want[i].Type)
		haspointers(inp[i].Type)
	}

	nl := slice2nodelist(inp)
	listsort(&nl, cmpstackvarlt)
	got := nodelist2slice(nl)
	if !reflect.DeepEqual(want, got) {
		t.Error("listsort failed")
		for i := range got {
			g := got[i]
			w := want[i]
			eq := reflect.DeepEqual(w, g)
			if !eq {
				t.Log(i, w, g)
			}
		}
	}
}