func (f *Function) If(instr *ssa.If) (string, *Error) {
asm := ""
ctx := context{f, instr}
tblock, fblock := -1, -1
if instr.Block() != nil && len(instr.Block().Succs) == 2 {
tblock = instr.Block().Succs[0].Index
fblock = instr.Block().Succs[1].Index
}
if tblock == -1 || fblock == -1 {
ice("malformed CFG with if stmt")
}
cond, ok := f.identifiers[instr.Cond.Name()]
if !ok {
return ErrorMsg(fmt.Sprintf("If: unhandled case, cond (%v)", instr.Cond))
}
a, reg, err := f.LoadIdentSimple(instr, cond)
if err != nil {
return "", err
}
asm += a
a, err = f.JumpPreamble(instr, instr.Block().Index, fblock)
if err != nil {
return "", err
}
asm += a
asm += CmpRegImm32(ctx, reg, uint32(0), cond.size())
f.freeReg(reg)
asm += fmt.Sprintf("%-9v ", JEQ) + "block" + strconv.Itoa(fblock) + "\n"
a, err = f.JumpPreamble(instr, instr.Block().Index, tblock)
if err != nil {
return "", err
}
asm += a
jmp := "JMP"
asm += fmt.Sprintf("%-9v ", jmp) + "block" + strconv.Itoa(tblock) + "\n"
asm = fmt.Sprintf("// BEGIN ssa.If, %v\n", instr) + asm
asm += fmt.Sprintf("// END ssa.If, %v\n", instr)
return asm, nil
}
func visitIf(instr *ssa.If, infer *TypeInfer, ctx *Context) {
if len(instr.Block().Succs) != 2 {
infer.Logger.Fatal(ErrInvalidIfSucc)
}
// Detect and unroll ctx.L.
if ctx.L.State != NonLoop && ctx.L.Bound == Static && instr.Cond == ctx.L.CondVar {
if ctx.L.HasNext() {
infer.Logger.Printf(ctx.F.Sprintf(LoopSymbol+"loop continue %s", ctx.L))
visitBasicBlock(instr.Block().Succs[0], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[0], ctx.B.Index), ctx.L)
} else {
infer.Logger.Printf(ctx.F.Sprintf(LoopSymbol+"loop exit %s", ctx.L))
visitBasicBlock(instr.Block().Succs[1], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[1], ctx.B.Index), ctx.L)
}
return
}
// Detect Select branches.
if bin, ok := instr.Cond.(*ssa.BinOp); ok && bin.Op == token.EQL {
for _, sel := range ctx.F.selects {
if bin.X == sel.Index.(*Value).Value {
if i, ok := bin.Y.(*ssa.Const); ok && i.Value.Kind() == constant.Int {
//infer.Logger.Print(fmt.Sprintf("[select-%d]", i.Int64()), ctx.F.FuncDef.String())
parDef := ctx.F.FuncDef
parDef.PutAway() // Save select
visitBasicBlock(instr.Block().Succs[0], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[0], ctx.B.Index), ctx.L)
ctx.F.FuncDef.PutAway() // Save case
selCase, err := ctx.F.FuncDef.Restore()
if err != nil {
infer.Logger.Fatal("select-case:", err)
}
sel.MigoStmt.Cases[i.Int64()] = append(sel.MigoStmt.Cases[i.Int64()], selCase...)
selParent, err := parDef.Restore()
if err != nil {
infer.Logger.Fatal("select-parent:", err)
}
parDef.AddStmts(selParent...)
// Test if select has default branch & if this is default
if !sel.Instr.Blocking && i.Int64() == int64(len(sel.Instr.States)-1) {
infer.Logger.Print(ctx.F.Sprintf(SelectSymbol + "default"))
if instr.Block().Succs[1].Comment == "select.done" {
// Looks like it's empty
infer.Logger.Printf(SplitSymbol+"Empty default branch (%d ⇾ %d)", instr.Block().Index, instr.Block().Succs[1].Index)
selDefault := &migo.CallStatement{Name: fmt.Sprintf("%s#%d", ctx.F.Fn.String(), instr.Block().Succs[1].Index)}
for i := 0; i < len(ctx.F.FuncDef.Params); i++ {
for k, ea := range ctx.F.extraargs {
if phi, ok := ea.(*ssa.Phi); ok {
if instr.Block().Succs[1].Index < len(phi.Edges) {
for _, e := range phi.Edges {
if ctx.F.FuncDef.Params[i].Caller.Name() == e.Name() {
ctx.F.FuncDef.Params[i].Callee = phi
// Remove from extra args
if k < len(ctx.F.extraargs) {
ctx.F.extraargs = append(ctx.F.extraargs[:k], ctx.F.extraargs[k+1:]...)
} else {
ctx.F.extraargs = ctx.F.extraargs[:k]
}
}
}
}
}
}
// This loop copies args from current function to Successor.
if phi, ok := ctx.F.FuncDef.Params[i].Callee.(*ssa.Phi); ok {
// Resolve in current scope if phi
selDefault.AddParams(&migo.Parameter{Caller: phi.Edges[instr.Block().Succs[1].Index], Callee: ctx.F.FuncDef.Params[i].Callee})
} else {
selDefault.AddParams(&migo.Parameter{Caller: ctx.F.FuncDef.Params[i].Callee, Callee: ctx.F.FuncDef.Params[i].Callee})
}
}
for _, ea := range ctx.F.extraargs {
if phi, ok := ea.(*ssa.Phi); ok {
selDefault.AddParams(&migo.Parameter{Caller: phi.Edges[instr.Block().Succs[1].Index], Callee: phi})
} else {
selDefault.AddParams(&migo.Parameter{Caller: ea, Callee: ea})
}
}
parDef := ctx.F.FuncDef
parDef.PutAway() // Save select
sel.MigoStmt.Cases[len(sel.MigoStmt.Cases)-1] = append(sel.MigoStmt.Cases[len(sel.MigoStmt.Cases)-1], selDefault)
selParent, err := parDef.Restore()
if err != nil {
infer.Logger.Fatal("select-parent:", err)
}
parDef.AddStmts(selParent...)
} else {
parDef := ctx.F.FuncDef
parDef.PutAway() // Save select
visitBasicBlock(instr.Block().Succs[1], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[1], ctx.B.Index), ctx.L)
ctx.F.FuncDef.PutAway() // Save case
selDefault, err := ctx.F.FuncDef.Restore()
if err != nil {
infer.Logger.Fatal("select-default:", err)
}
sel.MigoStmt.Cases[len(sel.MigoStmt.Cases)-1] = append(sel.MigoStmt.Cases[len(sel.MigoStmt.Cases)-1], selDefault...)
selParent, err := parDef.Restore()
if err != nil {
infer.Logger.Fatal("select-parent:", err)
}
parDef.AddStmts(selParent...)
}
} else {
infer.Logger.Printf(ctx.F.Sprintf(IfSymbol+"select-else "+JumpSymbol+"%d", instr.Block().Succs[1].Index))
visitBasicBlock(instr.Block().Succs[1], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[1], ctx.B.Index), ctx.L)
}
return // Select if-then-else handled
}
}
}
}
var cond string
if inst, ok := ctx.F.locals[instr.Cond]; ok && isCommaOk(ctx.F, inst) {
cond = fmt.Sprintf("comma-ok %s", instr.Cond.Name())
} else {
cond = fmt.Sprintf("%s", instr.Cond.Name())
}
// Save parent.
ctx.F.FuncDef.PutAway()
infer.Logger.Printf(ctx.F.Sprintf(IfSymbol+"if %s then"+JumpSymbol+"%d", cond, instr.Block().Succs[0].Index))
visitBasicBlock(instr.Block().Succs[0], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[0], ctx.B.Index), ctx.L)
// Save then.
ctx.F.FuncDef.PutAway()
infer.Logger.Printf(ctx.F.Sprintf(IfSymbol+"if %s else"+JumpSymbol+"%d", cond, instr.Block().Succs[1].Index))
if ctx.L.State == Body && ctx.L.LoopBlock == ctx.B.Index {
// Infinite loop.
infer.Logger.Printf(ctx.F.Sprintf(LoopSymbol + " infinite loop"))
stmt := &migo.CallStatement{Name: fmt.Sprintf("%s#%d", ctx.F.Fn.String(), ctx.B.Index)}
for _, p := range ctx.F.FuncDef.Params {
stmt.AddParams(&migo.Parameter{Caller: p.Callee, Callee: p.Callee})
}
ctx.F.FuncDef.AddStmts(stmt)
} else {
visitBasicBlock(instr.Block().Succs[1], infer, ctx.F, NewBlock(ctx.F, instr.Block().Succs[1], ctx.B.Index), ctx.L)
}
// Save else.
ctx.F.FuncDef.PutAway()
elseStmts, err := ctx.F.FuncDef.Restore() // Else
if err != nil {
infer.Logger.Fatal("restore else:", err)
}
thenStmts, err := ctx.F.FuncDef.Restore() // Then
if err != nil {
infer.Logger.Fatal("restore then:", err)
}
parentStmts, err := ctx.F.FuncDef.Restore() // Parent
if err != nil {
infer.Logger.Fatal("restore if-then-else parent:", err)
}
ctx.F.FuncDef.AddStmts(parentStmts...)
ctx.F.FuncDef.AddStmts(&migo.IfStatement{Then: thenStmts, Else: elseStmts})
}
func visitIf(inst *ssa.If, fr *frame) {
if len(inst.Block().Succs) != 2 {
panic("If: Cannot handle If with more or less than 2 successor blocks!")
}
ifparent := fr.gortn.leaf
if ifparent == nil {
panic("If: Parent is nil")
}
if ch, isRecvTest := fr.env.recvTest[inst.Cond]; isRecvTest {
fmt.Fprintf(os.Stderr, " @ Switch to recvtest true\n")
fr.gortn.leaf = ifparent
fr.gortn.AddNode(sesstype.NewRecvNode(*ch, fr.gortn.role, ch.Type()))
fmt.Fprintf(os.Stderr, " %s\n", orange((*fr.gortn.leaf).String()))
visitBlock(inst.Block().Succs[0], fr)
fmt.Fprintf(os.Stderr, " @ Switch to recvtest false\n")
fr.gortn.leaf = ifparent
fr.gortn.AddNode(sesstype.NewRecvStopNode(*ch, fr.gortn.role, ch.Type()))
fmt.Fprintf(os.Stderr, " %s\n", orange((*fr.gortn.leaf).String()))
visitBlock(inst.Block().Succs[1], fr)
} else if selTest, isSelTest := fr.env.selTest[inst.Cond]; isSelTest {
// Check if this is a select-test-jump, if so handle separately.
fmt.Fprintf(os.Stderr, " @ Switch to select branch #%d\n", selTest.idx)
if selParent, ok := fr.env.selNode[selTest.tpl]; ok {
fr.gortn.leaf = ifparent
*fr.gortn.leaf = (*selParent.parent).Child(selTest.idx)
visitBlock(inst.Block().Succs[0], fr)
if !selParent.blocking && len((*selParent.parent).Children()) > selTest.idx+1 {
*fr.gortn.leaf = (*selParent.parent).Child(selTest.idx + 1)
}
visitBlock(inst.Block().Succs[1], fr)
} else {
panic("Select without corresponding sesstype.Node")
}
} else {
fr.env.ifparent.Push(*fr.gortn.leaf)
parent := fr.env.ifparent.Top()
fr.gortn.leaf = &parent
fr.gortn.AddNode(&sesstype.EmptyBodyNode{})
visitBlock(inst.Block().Succs[0], fr)
parent = fr.env.ifparent.Top()
fr.gortn.leaf = &parent
fr.gortn.AddNode(&sesstype.EmptyBodyNode{})
visitBlock(inst.Block().Succs[1], fr)
fr.env.ifparent.Pop()
}
// This is end of the block so no continuation
}