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package pass
import (
"reflect"
"sort"
"testing"
"github.com/mmcloughlin/avo/ir"
"github.com/mmcloughlin/avo/operand"
)
func TestLabelTarget(t *testing.T) {
expect := map[ir.Label]*ir.Instruction{
"lblA": {Opcode: "A"},
"lblB": {Opcode: "B"},
}
f := ir.NewFunction("happypath")
for lbl, i := range expect {
f.AddLabel(lbl)
f.AddComment("comments should be ignored")
f.AddInstruction(i)
f.AddInstruction(&ir.Instruction{Opcode: "IDK"})
}
if err := LabelTarget(f); err != nil {
t.Fatal(err)
}
if !reflect.DeepEqual(expect, f.LabelTarget) {
t.Fatalf("incorrect LabelTarget value\ngot=%#v\nexpext=%#v\n", f.LabelTarget, expect)
}
}
func TestLabelTargetDuplicate(t *testing.T) {
f := ir.NewFunction("dupelabel")
f.AddLabel(ir.Label("lblA"))
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddLabel(ir.Label("lblA"))
f.AddInstruction(&ir.Instruction{Opcode: "A"})
err := LabelTarget(f)
if err == nil || err.Error() != "duplicate label \"lblA\"" {
t.Fatalf("expected error on duplcate label; got %v", err)
}
}
func TestLabelTargetEndsWithLabel(t *testing.T) {
f := ir.NewFunction("endswithlabel")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddLabel(ir.Label("theend"))
err := LabelTarget(f)
if err == nil || err.Error() != "function ends with label" {
t.Fatalf("expected error when function ends with label; got %v", err)
}
}
func TestLabelTargetConsecutiveLabels(t *testing.T) {
i := &ir.Instruction{Opcode: "A"}
f := ir.NewFunction("consecutivelabels")
f.AddLabel(ir.Label("lblA"))
f.AddLabel(ir.Label("lblB"))
f.AddInstruction(i)
expect := map[ir.Label]*ir.Instruction{
"lblA": i,
"lblB": i,
}
if err := LabelTarget(f); err != nil {
t.Fatal(err)
}
if !reflect.DeepEqual(expect, f.LabelTarget) {
t.Fatalf("incorrect LabelTarget value\ngot=%#v\nexpext=%#v\n", f.LabelTarget, expect)
}
}
func TestCFGSingleBasicBlock(t *testing.T) {
f := ir.NewFunction("simple")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddInstruction(&ir.Instruction{Opcode: "B"})
f.AddInstruction(Terminal("RET"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"A": {"B"},
"B": {"RET"},
"RET": {},
})
AssertPredecessors(t, f, map[string][]string{
"A": {},
"B": {"A"},
"RET": {"B"},
})
}
func TestCFGCondBranch(t *testing.T) {
f := ir.NewFunction("condbranch")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddLabel(ir.Label("lblB"))
f.AddInstruction(&ir.Instruction{Opcode: "B"})
f.AddInstruction(&ir.Instruction{Opcode: "C"})
f.AddInstruction(CondBranch("J", "lblB"))
f.AddInstruction(Terminal("RET"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"A": {"B"},
"B": {"C"},
"C": {"J"},
"J": {"B", "RET"},
"RET": {},
})
}
func TestCFGUncondBranch(t *testing.T) {
f := ir.NewFunction("uncondbranch")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddLabel(ir.Label("lblB"))
f.AddInstruction(&ir.Instruction{Opcode: "B"})
f.AddInstruction(UncondBranch("JMP", "lblB"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"A": {"B"},
"B": {"JMP"},
"JMP": {"B"},
})
}
func TestCFGJumpForward(t *testing.T) {
f := ir.NewFunction("forward")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddInstruction(CondBranch("J", "done"))
f.AddInstruction(&ir.Instruction{Opcode: "B"})
f.AddLabel(ir.Label("done"))
f.AddInstruction(Terminal("RET"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"A": {"J"},
"J": {"B", "RET"},
"B": {"RET"},
"RET": {},
})
}
func TestCFGMultiReturn(t *testing.T) {
f := ir.NewFunction("multireturn")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddInstruction(CondBranch("J", "fork"))
f.AddInstruction(&ir.Instruction{Opcode: "B"})
f.AddInstruction(Terminal("RET1"))
f.AddLabel(ir.Label("fork"))
f.AddInstruction(&ir.Instruction{Opcode: "C"})
f.AddInstruction(Terminal("RET2"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"A": {"J"},
"J": {"B", "C"},
"B": {"RET1"},
"RET1": {},
"C": {"RET2"},
"RET2": {},
})
}
func TestCFGShortLoop(t *testing.T) {
f := ir.NewFunction("shortloop")
f.AddLabel(ir.Label("cycle"))
f.AddInstruction(UncondBranch("JMP", "cycle"))
if err := ComputeCFG(t, f); err != nil {
t.Fatal(err)
}
AssertSuccessors(t, f, map[string][]string{
"JMP": {"JMP"},
})
}
func TestCFGUndefinedLabel(t *testing.T) {
f := ir.NewFunction("undeflabel")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddInstruction(CondBranch("J", "undef"))
err := ComputeCFG(t, f)
if err == nil {
t.Fatal("expect error on undefined label")
}
}
func TestCFGMissingLabel(t *testing.T) {
f := ir.NewFunction("missinglabel")
f.AddInstruction(&ir.Instruction{Opcode: "A"})
f.AddInstruction(&ir.Instruction{Opcode: "J", IsBranch: true}) // no label operand
err := ComputeCFG(t, f)
if err == nil {
t.Fatal("expect error on missing label")
}
}
// Terminal builds a terminal instruction.
func Terminal(opcode string) *ir.Instruction {
return &ir.Instruction{Opcode: opcode, IsTerminal: true}
}
// CondBranch builds a conditional branch instruction to the given label.
func CondBranch(opcode, lbl string) *ir.Instruction {
return &ir.Instruction{
Opcode: opcode,
Operands: []operand.Op{operand.LabelRef(lbl)},
IsBranch: true,
IsConditional: true,
}
}
// UncondBranch builds an unconditional branch instruction to the given label.
func UncondBranch(opcode, lbl string) *ir.Instruction {
return &ir.Instruction{
Opcode: opcode,
Operands: []operand.Op{operand.LabelRef(lbl)},
IsBranch: true,
IsConditional: false,
}
}
func ComputeCFG(t *testing.T, f *ir.Function) error {
t.Helper()
if err := LabelTarget(f); err != nil {
t.Fatal(err)
}
return CFG(f)
}
func AssertSuccessors(t *testing.T, f *ir.Function, expect map[string][]string) {
AssertEqual(t, "successors", OpcodeSuccessorGraph(f), expect)
}
func AssertPredecessors(t *testing.T, f *ir.Function, expect map[string][]string) {
AssertEqual(t, "predecessors", OpcodePredecessorGraph(f), expect)
}
func AssertEqual(t *testing.T, what string, got, expect interface{}) {
t.Logf("%s=%#v\n", what, got)
if reflect.DeepEqual(expect, got) {
return
}
t.Fatalf("bad %s; expected=%#v", what, expect)
}
// OpcodeSuccessorGraph builds a map from opcode name to successor opcode names.
func OpcodeSuccessorGraph(f *ir.Function) map[string][]string {
return OpcodeGraph(f, func(i *ir.Instruction) []*ir.Instruction { return i.Succ })
}
// OpcodePredecessorGraph builds a map from opcode name to predecessor opcode names.
func OpcodePredecessorGraph(f *ir.Function) map[string][]string {
return OpcodeGraph(f, func(i *ir.Instruction) []*ir.Instruction { return i.Pred })
}
// OpcodeGraph builds a map from opcode name to neighboring opcode names. Each list of neighbors is sorted.
func OpcodeGraph(f *ir.Function, neighbors func(*ir.Instruction) []*ir.Instruction) map[string][]string {
g := map[string][]string{}
for _, i := range f.Instructions() {
opcodes := []string{}
for _, n := range neighbors(i) {
opcode := "<nil>"
if n != nil {
opcode = n.Opcode
}
opcodes = append(opcodes, opcode)
}
sort.Strings(opcodes)
g[i.Opcode] = opcodes
}
return g
}
|
