func finalEdits(prog *cc.Prog) {
cc.Postorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Expr:
if x.Op == cc.Arrow && x.Text == "prg" && c2go.GoString(x.Left) == "ctxt.arch" {
x.Left = x.Left.Left // drop arch.
}
}
})
}
// Rewrite from C constructs to Go constructs.
func rewriteSyntax(prog *cc.Prog) {
cc.Preorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Stmt:
rewriteStmt(x)
case *cc.Expr:
switch x.Op {
case cc.Number:
// Rewrite char literal.
// In general we'd need to rewrite all string and char literals
// but these are the only forms that comes up.
switch x.Text {
case `'\0'`:
x.Text = `'\x00'`
case `'\"'`:
x.Text = `'"'`
}
case cc.Paren:
switch x.Left.Op {
case cc.Number, cc.Name:
fixMerge(x, x.Left)
}
case cc.OrEq, cc.AndEq, cc.Or, cc.Eq, cc.EqEq, cc.NotEq, cc.LtEq, cc.GtEq, cc.Lt, cc.Gt:
cutParen(x, cc.Or, cc.And, cc.Lsh, cc.Rsh)
}
case *cc.Type:
// Rewrite int f(void) to int f().
if x.Kind == cc.Func && len(x.Decls) == 1 && x.Decls[0].Name == "" && x.Decls[0].Type.Is(cc.Void) {
x.Decls = nil
}
}
})
// Apply changed struct tags to typedefs.
// Excise dead pieces.
cc.Postorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Type:
if x.Kind == cc.TypedefType && x.Base != nil && x.Base.Tag != "" {
x.Name = x.Base.Tag
}
case *cc.Stmt:
if x.Op == cc.StmtExpr && x.Expr.Op == cc.Comma && len(x.Expr.List) == 0 {
x.Op = cc.Empty
}
x.Block = filterBlock(x.Block)
case *cc.Expr:
if x.Op == c2go.ExprBlock {
x.Block = filterBlock(x.Block)
}
switch x.Op {
case cc.Add, cc.Sub:
// Turn p + y - z, which is really (p + y) - z, into p + (y - z),
// so that there is only one pointer addition (which will turn into
// a slice operation using y-z as the index).
if x.XType != nil && x.XType.Kind == cc.Ptr {
switch x.Left.Op {
case cc.Add, cc.Sub:
if x.Left.XType != nil && x.Left.XType.Kind == cc.Ptr {
p, op1, y, op2, z := x.Left.Left, x.Left.Op, x.Left.Right, x.Op, x.Right
if op1 == cc.Sub {
y = &cc.Expr{Op: cc.Minus, Left: y, XType: y.XType}
}
x.Op = cc.Add
x.Left = p
x.Right = &cc.Expr{Op: op2, Left: y, Right: z, XType: x.XType}
}
}
}
}
// Turn c + p - q, which is really (c + p) - q, into c + (p - q),
// so that there is no int + ptr addition, only a ptr - ptr subtraction.
if x.Op == cc.Sub && x.Left.Op == cc.Add && !isPtrOrArray(x.XType) && isPtrOrArray(x.Left.XType) && !isPtrOrArray(x.Left.Left.XType) {
c, p, q := x.Left.Left, x.Left.Right, x.Right
expr := x.Left
expr.Left = p
expr.Right = q
expr.Op = cc.Sub
x.Op = cc.Add
x.Left = c
x.Right = expr
expr.XType = x.XType
}
}
})
}
func inferTypes(cfg *Config, prog *cc.Prog) {
cc.Postorder(prog, func(x cc.Syntax) {
if t, ok := x.(*cc.Type); ok {
if t.Kind == cc.Struct || t.Kind == cc.Enum {
for _, d := range t.Decls {
d.OuterType = t
}
}
}
})
addFlow(cfg, prog)
for _, f := range flowCache {
if f.group != nil {
continue
}
g := &flowGroup{}
if f.stopFlow {
addToGroup(g, f)
continue
}
exploreGroup(g, f)
if len(g.decls) == 0 {
continue
}
flowGroups = append(flowGroups, g)
}
sort.Sort(flowGroupsBySize(flowGroups))
for _, g := range flowGroups {
var typ *cc.Type
var typDecl *cc.Decl
for _, d := range g.decls {
if d.Type == nil {
continue
}
dt := d.Type.Def()
if typ == nil || typ.Kind == cc.Ptr && typ.Base.Is(cc.Void) {
typ = dt
typDecl = d
}
if !inferCompatible(dt, typ) {
fmt.Printf("BAD INFER: mixing %v (%v) and %v (%v)\n", typ, declKey(typDecl), d.Type, declKey(d))
findFlowPath(flowCache[typDecl], flowCache[d])
os.Exit(1)
}
if isNumericCType(typ) && isNumericCType(dt) && typ.Kind == cc.Enum || dt.Kind != cc.Enum && typ.Kind < dt.Kind {
typ = dt
typDecl = d
}
}
g.canon = typ
g.canonDecl = typDecl
}
for _, g := range flowGroups {
for _, f := range g.syntax {
if f.usedAsBool {
g.isBool = isNumericCType(g.canon) && g.canon.Kind <= cc.Int
break
}
}
}
for {
changed := false
for _, g := range flowGroups {
if !g.isBool {
continue
}
for _, f := range g.syntax {
x, ok := f.syntax.(*cc.Expr)
if !ok {
continue
}
switch x.Op {
case cc.EqEq, cc.LtEq, cc.GtEq, cc.NotEq, cc.Lt, cc.Gt, cc.AndAnd, cc.OrOr:
continue
case cc.Number:
if x.Text == "0" || x.Text == "1" {
continue
}
case cc.Call:
if x.Left.Op == cc.Name {
f := flowCache[x.Left.XDecl]
if f != nil && f.returnValue != nil && f.returnValue.group != nil && f.returnValue.group.isBool {
continue
}
}
}
// can't be bool
changed = true
g.isBool = false
}
}
if !changed {
break
}
}
if *src != "" && *dst != "" {
var fsrc, fdst *flowSyntax
for _, f := range flowCache {
d, ok := f.syntax.(*cc.Decl)
if ok {
key := declKey(d)
if key == "" {
continue
}
if *src == key {
fsrc = f
fmt.Printf("%s in %p %p\n", key, f, f.group)
}
if strings.HasSuffix(*src, key) {
fmt.Printf("near: %s\n", key)
}
if *dst == key {
fdst = f
fmt.Printf("%s in %p %p\n", key, f, f.group)
}
if strings.HasSuffix(*dst, key) {
fmt.Printf("near: %s\n", key)
}
}
}
if fsrc != nil && fdst != nil {
findFlowPath(fsrc, fdst)
os.Exit(0)
}
fmt.Printf("%s and %s are not in the same group\n", *src, *dst)
os.Exit(0)
}
}
// Rewrite C types to be Go types.
func rewriteTypes(prog cc.Syntax) {
// Assign overrides to groups.
cc.Postorder(prog, func(x cc.Syntax) {
if d, ok := x.(*cc.Decl); ok {
key := declKey(d)
t := override[key]
if t == nil {
return
}
if t.Kind == cc.Array {
// Override only applies to specific decl. Skip for now.
return
}
f := flowCache[d]
if f == nil {
return
}
g := f.group
if g.goKind != 0 || g.goType != nil {
fmt.Fprintf(os.Stderr, "multiple overrides: %v (%p) and %v (%p)\n", key, f.group, g.goKey, g.goFlow.group)
}
g.goKey = key
g.goFlow = f
if t.Kind <= cc.Enum {
panic("bad go type override")
}
if (t.Kind == cc.Ptr || t.Kind == c2go.Slice) && t.Base == nil {
g.goKind = t.Kind
} else {
g.goType = t
}
}
})
// Process overrides.
cache := make(map[*cc.Type]*cc.Type)
for _, g := range flowGroups {
if g.goType != nil {
continue
}
if c2go.Int8 <= g.goKind && g.goKind <= c2go.Float64 {
g.goType = &cc.Type{Kind: g.goKind}
continue
}
if g.goKind == cc.Ptr || g.goKind == c2go.Slice {
t := g.decls[0].Type
if t == nil || t.Base == nil {
fmt.Printf("%s: expected ptr/array/slice for %s\n", g.decls[0].Span, declKey(g.decls[0]))
continue
}
g.goType = &cc.Type{Kind: g.goKind, Base: toGoType(nil, nil, t.Base, cache)}
continue
}
if g.goKind != 0 {
fmt.Printf("%s: unexpected go kind %v\n", g.goKey, g.goKind)
continue
}
}
// Process defaults.
// Each group has a 'canonical' instance of the type
// that we can use as the initial hint.
for _, g := range flowGroups {
if g.goType != nil {
continue
}
if g.canon == nil {
fmt.Printf("group missing canonical\n")
continue
}
if g.isBool {
g.goType = boolType
continue
}
t := g.canon.Def()
if cc.Char <= t.Kind && t.Kind <= cc.Enum {
// Convert to an appropriately sized number.
// Canon is largest rank from C; convert to Go.
g.goType = &cc.Type{Kind: c2goKind[t.Kind]}
continue
}
if t.Kind == cc.Ptr || t.Kind == cc.Array {
// Default is convert to pointer.
// If there are any arrays or any pointer arithmetic, convert to slice instead.
k := cc.Ptr
for _, d := range g.decls {
if d.Type != nil && d.Type.Kind == cc.Array {
k = c2go.Slice
}
}
for _, f := range g.syntax {
if f.ptrAdd {
k = c2go.Slice
}
}
if t.Base.Kind == cc.Char {
g.goType = &cc.Type{Kind: c2go.String}
continue
}
g.goType = &cc.Type{Kind: k, Base: toGoType(nil, nil, t.Base, cache)}
continue
}
}
if *showGroups {
fmt.Printf("%d groups\n", len(flowGroups))
for _, g := range flowGroups {
suffix := ""
if g.isBool {
suffix = " [bool]"
}
fmt.Printf("group(%d): %v (canon %v)%s\n", len(g.decls), c2go.GoString(g.goType), c2go.GoString(g.canon), suffix)
for i := 0; i < 2; i++ {
for _, f := range g.syntax {
if d, ok := f.syntax.(*cc.Decl); ok == (i == 0) {
suffix := ""
if ok {
suffix = ": " + declKey(d) + " " + c2go.GoString(d.Type)
}
if f.ptrAdd {
suffix += " (ptradd)"
}
if f.usedAsBool {
suffix += " (bool)"
}
fmt.Printf("\t%s %v%s\n", f.syntax.GetSpan(), f.syntax, suffix)
}
}
}
}
}
// Apply grouped decisions to individual declarations.
cc.Postorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Decl:
d := x
if d.Name == "..." || d.Type == nil {
return
}
if d.Name == "" && d.Type.Is(cc.Enum) && len(d.Type.Decls) > 0 {
for _, dd := range d.Type.Decls {
dd.Type = idealType
}
return
}
t := override[declKey(d)]
if t != nil && t.Kind == cc.Array {
d.Type = t
return
}
f := flowCache[d]
if f == nil {
d.Type = toGoType(nil, d, d.Type, cache)
if declKey(d) != "tmp" {
fprintf(d.Span, "missing flow group for %s", d.Span, declKey(d))
}
return
}
g := f.group
if d.Init != nil && len(d.Init.Braced) > 0 && d.Type != nil && d.Type.Kind == cc.Array {
// Initialization of array - do not override type.
// But if size is not given explicitly, change to slice.
d.Type.Base = toGoType(nil, nil, d.Type.Base, cache)
if d.Type.Width == nil {
d.Type.Kind = c2go.Slice
}
return
}
d.Type = toGoType(g, d, d.Type, cache)
if d.Type != nil && d.Type.Kind == cc.Func && d.Type.Base.Kind != cc.Void {
if f != nil && f.returnValue != nil && f.returnValue.group != nil && f.returnValue.group.goType != nil {
d.Type.Base = f.returnValue.group.goType
}
}
case *cc.Expr:
if x.Type != nil {
t := toGoType(nil, nil, x.Type, cache)
if t == nil {
fprintf(x.Span, "cannot convert %v to go type\n", c2go.GoString(x.Type))
}
x.Type = t
}
}
})
}
func rewriteLen(cfg *Config, prog *cc.Prog) {
cc.Postorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Expr:
// Assign to len, generated by len rewrite. Change to reslice.
if x.Op == cc.Eq && x.Left.Op == cc.Call && x.Left.Left.Op == cc.Name && x.Left.Left.Text == "len" && len(x.Left.List) > 0 {
arg := x.Left.List[0]
x.Left = arg
x.Right = &cc.Expr{
Op: c2go.ExprSlice,
List: []*cc.Expr{arg, nil, x.Right},
}
return
}
if (x.Op == cc.Arrow || x.Op == cc.Dot) && x.XDecl != nil {
k := declKey(x.XDecl)
name := cfg.Len[k]
if name == "" {
return
}
d := x.XDecl
if d.OuterType == nil {
fmt.Fprintf(os.Stderr, "found use of %s but missing type\n", k)
return
}
t := d.OuterType
var other *cc.Decl
for _, dd := range t.Decls {
if dd.Name == name {
other = dd
break
}
}
if other == nil {
fmt.Fprintf(os.Stderr, "found use of %s but cannot find field %s\n", k, name)
return
}
left := x.Left
x.Op = cc.Call
x.Left = &cc.Expr{
Op: cc.Name,
Text: "len",
XType: &cc.Type{Kind: cc.Func, Base: intType},
}
x.List = []*cc.Expr{
{
Op: cc.Dot,
Left: left,
Text: name,
XDecl: other,
},
}
}
}
})
cc.Postorder(prog, func(x cc.Syntax) {
switch x := x.(type) {
case *cc.Type:
out := x.Decls[:0]
for _, d := range x.Decls {
k := declKey(d)
if cfg.Len[k] == "" && !cfg.Delete[k] {
out = append(out, d)
}
}
x.Decls = out
}
})
}