Changed xgbgen to support xcb-proto 1.12

* Added minimal support for switch fields.
* Changed the way Size is calculated to accomodate for lists inside structs
  (added to randr)
* Removed heuristic to place alignment gaps, they are now explicitly
  described in xml

nexgb/xgbgen/aligngap.go

@@ -1,120 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"os"
-)
-
-func (p *Protocol) AddAlignGaps() {
-	for i := range p.Imports {
-		p.Imports[i].AddAlignGaps()
-	}
-	for i := range p.Types {
-		switch t := p.Types[i].(type) {
-		case *Struct:
-			t.Fields = addAlignGapsToFields(t.xmlName, t.Fields)
-		case *Event:
-			t.Fields = addAlignGapsToFields(t.xmlName, t.Fields)
-		case *Error:
-			t.Fields = addAlignGapsToFields(t.xmlName, t.Fields)
-		}
-	}
-	for i := range p.Requests {
-		p.Requests[i].Fields = addAlignGapsToFields(
-			p.Requests[i].xmlName, p.Requests[i].Fields)
-		if p.Requests[i].Reply != nil {
-			p.Requests[i].Reply.Fields = addAlignGapsToFields(
-				p.Requests[i].xmlName, p.Requests[i].Reply.Fields)
-		}
-	}
-}
-
-func addAlignGapsToFields(name string, fields []Field) []Field {
-	var i int
-	for i = 0; i < len(fields); i++ {
-		if _, ok := fields[i].(*ListField); ok {
-			break
-		}
-	}
-	if i >= len(fields) {
-		return fields
-	}
-
-	r := make([]Field, 0, len(fields)+2)
-	r = append(r, fields[:i]...)
-
-	r = append(r, fields[i])
-	for i = i + 1; i < len(fields); i++ {
-		switch f := fields[i].(type) {
-		case *ListField:
-			// ok, add padding
-			sz := xcbSizeOfType(f.Type)
-			switch {
-			case sz == 1:
-				// nothing
-			case sz == 2:
-				r = append(r, &PadField{0, 2})
-			case sz == 3:
-				panic(fmt.Errorf("Alignment is not a power of 2"))
-			case sz >= 4:
-				r = append(r, &PadField{0, 4})
-			}
-		case *LocalField:
-			// nothing
-		default:
-			fmt.Fprintf(os.Stderr,
-				"Can't add alignment gaps, mix of list and non-list "+
-					"fields: %s\n", name)
-			return fields
-		}
-		r = append(r, fields[i])
-	}
-	return r
-}
-
-func xcbSizeOfField(fld Field) int {
-	switch f := fld.(type) {
-	case *PadField:
-		return int(f.Bytes)
-	case *SingleField:
-		return xcbSizeOfType(f.Type)
-	case *ListField:
-		return 0
-	case *ExprField:
-		return xcbSizeOfType(f.Type)
-	case *ValueField:
-		return xcbSizeOfType(f.MaskType)
-	case *SwitchField:
-		return 0
-	default:
-		return 0
-	}
-}
-
-func xcbSizeOfType(typ Type) int {
-	switch t := typ.(type) {
-	case *Resource:
-		return 4
-	case *TypeDef:
-		return t.Size().Eval()
-	case *Base:
-		return t.Size().Eval()
-	case *Struct:
-		sz := 0
-		for i := range t.Fields {
-			sz += xcbSizeOfField(t.Fields[i])
-		}
-		return sz
-	case *Union:
-		sz := 0
-		for i := range t.Fields {
-			csz := xcbSizeOfField(t.Fields[i])
-			if csz > sz {
-				sz = csz
-			}
-		}
-		return sz
-	default:
-		return 0
-	}
-}

nexgb/xgbgen/context.go

@@ -50,7 +50,22 @@ func (c *Context) Morph(xmlBytes []byte) {
 	// Translate XML types to nice types
 	c.protocol = parsedXml.Translate(nil)
 	
-	c.protocol.AddAlignGaps()
+	// For backwards compatibility we patch the type of the send_event field of
+	// PutImage to be byte
+	if c.protocol.Name == "shm" {
+		for _, req := range c.protocol.Requests {
+			if req.xmlName != "PutImage" {
+				continue
+			}
+			for _, ifield := range req.Fields {
+				field, ok := ifield.(*SingleField)
+				if !ok || field.xmlName != "send_event" {
+					continue
+				}
+				field.Type = &Base{ srcName: "byte", xmlName: "CARD8", size: newFixedSize(1, true) }
+			}
+		}
+	}
 
 	// Start with Go header.
 	c.Putln("// Package %s is the X client API for the %s extension.",

nexgb/xgbgen/expression.go

@@ -32,6 +32,9 @@ type Expression interface {
 	// Initialize makes sure all names in this expression and any subexpressions
 	// have been translated to Go source names.
 	Initialize(p *Protocol)
+
+	// Makes all field references relative to path
+	Specialize(path string) Expression
 }
 
 // Function is a custom expression not found in the XML. It's simply used
@@ -62,6 +65,12 @@ func (e *Function) Initialize(p *Protocol) {
 	e.Expr.Initialize(p)
 }
 
+func (e *Function) Specialize(path string) Expression {
+	r := *e
+	r.Expr = r.Expr.Specialize(path)
+	return &r
+}
+
 // BinaryOp is an expression that performs some operation (defined in the XML
 // file) with Expr1 and Expr2 as operands.
 type BinaryOp struct {
@@ -150,6 +159,13 @@ func (e *BinaryOp) Initialize(p *Protocol) {
 	e.Expr2.Initialize(p)
 }
 
+func (e *BinaryOp) Specialize(path string) Expression {
+	r := *e
+	r.Expr1 = r.Expr1.Specialize(path)
+	r.Expr2 = r.Expr2.Specialize(path)
+	return &r
+}
+
 // UnaryOp is the same as BinaryOp, except it's a unary operator with only
 // one sub-expression.
 type UnaryOp struct {
@@ -186,6 +202,12 @@ func (e *UnaryOp) Initialize(p *Protocol) {
 	e.Expr.Initialize(p)
 }
 
+func (e *UnaryOp) Specialize(path string) Expression {
+	r := *e
+	r.Expr = r.Expr.Specialize(path)
+	return &r
+}
+
 // Padding represents the application of the 'pad' function to some
 // sub-expression.
 type Padding struct {
@@ -215,6 +237,12 @@ func (e *Padding) Initialize(p *Protocol) {
 	e.Expr.Initialize(p)
 }
 
+func (e *Padding) Specialize(path string) Expression {
+	r := *e
+	r.Expr = r.Expr.Specialize(path)
+	return &r
+}
+
 // PopCount represents the application of the 'PopCount' function to
 // some sub-expression.
 type PopCount struct {
@@ -244,6 +272,12 @@ func (e *PopCount) Initialize(p *Protocol) {
 	e.Expr.Initialize(p)
 }
 
+func (e *PopCount) Specialize(path string) Expression {
+	r := *e
+	r.Expr = r.Expr.Specialize(path)
+	return &r
+}
+
 // Value represents some constant integer.
 type Value struct {
 	v int
@@ -267,6 +301,10 @@ func (e *Value) String() string {
 
 func (e *Value) Initialize(p *Protocol) {}
 
+func (e *Value) Specialize(path string) Expression {
+	return e
+}
+
 // Bit represents some bit whose value is computed by '1 << bit'.
 type Bit struct {
 	b int
@@ -290,6 +328,10 @@ func (e *Bit) String() string {
 
 func (e *Bit) Initialize(p *Protocol) {}
 
+func (e *Bit) Specialize(path string) Expression {
+	return e
+}
+
 // FieldRef represents a reference to some variable in the generated code
 // with name Name.
 type FieldRef struct {
@@ -321,6 +363,10 @@ func (e *FieldRef) Initialize(p *Protocol) {
 	e.Name = SrcName(p, e.Name)
 }
 
+func (e *FieldRef) Specialize(path string) Expression {
+	return &FieldRef{Name: path + "." + e.Name}
+}
+
 // EnumRef represents a reference to some enumeration field.
 // EnumKind is the "group" an EnumItem is the name of the specific enumeration
 // value inside that group.
@@ -351,6 +397,10 @@ func (e *EnumRef) Initialize(p *Protocol) {
 	e.EnumItem = SrcName(p, e.EnumItem)
 }
 
+func (e *EnumRef) Specialize(path string) Expression {
+	return e
+}
+
 // SumOf represents a summation of the variable in the generated code named by
 // Name. It is not currently used. (It's XKB voodoo.)
 type SumOf struct {
@@ -380,3 +430,7 @@ func (e *SumOf) String() string {
 func (e *SumOf) Initialize(p *Protocol) {
 	e.Name = SrcName(p, e.Name)
 }
+
+func (e *SumOf) Specialize(path string) Expression {
+	return e
+}

nexgb/xgbgen/field.go

@@ -73,6 +73,32 @@ func (p *PadField) Size() Size {
 	}
 }
 
+type RequiredStartAlign struct {
+}
+
+func (f *RequiredStartAlign) Initialize(p *Protocol) { }
+
+func (f *RequiredStartAlign) SrcName() string {
+	panic("illegal to take source name of a required_start_align field")
+}
+
+func (f *RequiredStartAlign) XmlName() string {
+	panic("illegal to take XML name of a required_start_align field")
+}
+
+func (f *RequiredStartAlign) SrcType() string {
+	panic("it is illegal to call SrcType on a required_start_align field")
+}
+
+func (f *RequiredStartAlign) Size() Size {
+	return newFixedSize(0, true)
+}
+
+func (f *RequiredStartAlign) Define(c *Context) { }
+
+func (f *RequiredStartAlign) Read(c *Context, prefix string) { }
+func (f *RequiredStartAlign) Write(c *Context, prefix string) { }
+
 // SingleField represents most of the fields in an XML protocol description.
 // It corresponds to any single value.
 type SingleField struct {
@@ -289,35 +315,72 @@ func (f *ValueField) Initialize(p *Protocol) {
 }
 
 // SwitchField represents a 'switch' element in the XML protocol description
-// file. It is not currently used. (i.e., it is XKB voodoo.)
+// file.
+// Currently we translate this to a slice of uint32 and let the user sort
+// through it. 
 type SwitchField struct {
+	xmlName string
 	Name     string
+	MaskName string
 	Expr     Expression
 	Bitcases []*Bitcase
 }
 
 func (f *SwitchField) SrcName() string {
-	panic("it is illegal to call SrcName on a SwitchField field")
+	return f.Name
 }
 
 func (f *SwitchField) XmlName() string {
-	panic("it is illegal to call XmlName on a SwitchField field")
+	return f.xmlName
 }
 
 func (f *SwitchField) SrcType() string {
-	panic("it is illegal to call SrcType on a SwitchField field")
+	return "[]uint32"
 }
 
-// XXX: This is a bit tricky. The size has to be represented as a non-concrete
-// expression that finds *which* bitcase fields are included, and sums the
-// sizes of those fields.
 func (f *SwitchField) Size() Size {
-	return newFixedSize(0, true)
+	// TODO: size expression used here is not correct unless every element of
+	// the switch is 32 bit long. This assumption holds for xproto but may not
+	// hold for other protocols (xkb?)
+	listSize := newExpressionSize(&Function{
+		Name: "xgb.Pad",
+		Expr: &BinaryOp{
+			Op:    "*",
+			Expr1: &Value{v: 4},
+			Expr2: &PopCount{
+				Expr: &Function{
+					Name: "int",
+					Expr: &FieldRef{
+						Name: f.MaskName,
+					},
+				},
+			},
+		},
+	}, true)
+	
+	return listSize
+}
+
+func (f *SwitchField) ListLength() Size {
+	return newExpressionSize(&PopCount{
+		Expr: &Function{
+			Name: "int",
+			Expr: &FieldRef{
+				Name: f.MaskName,
+			},
+		},
+	}, true)
 }
 
 func (f *SwitchField) Initialize(p *Protocol) {
+	f.xmlName = f.Name
 	f.Name = SrcName(p, f.Name)
 	f.Expr.Initialize(p)
+	fieldref, ok := f.Expr.(*FieldRef)
+	if !ok {
+		panic("switch field's expression not a fieldref")
+	}
+	f.MaskName = SrcName(p, fieldref.Name)
 	for _, bitcase := range f.Bitcases {
 		bitcase.Expr.Initialize(p)
 		for _, field := range bitcase.Fields {

nexgb/xgbgen/go.go

@@ -186,11 +186,8 @@ func (f *ValueField) Read(c *Context, prefix string) {
 }
 
 func (f *ValueField) Write(c *Context, prefix string) {
-	// big time mofos
-	if rq, ok := f.Parent.(*Request); !ok || rq.SrcName() != "ConfigureWindow" {
 	WriteSimpleSingleField(c,
 		fmt.Sprintf("%s%s", prefix, f.MaskName), f.MaskType)
-	}
 	c.Putln("for i := 0; i < %s; i++ {", f.ListLength().Reduce(prefix))
 	c.Putln("xgb.Put32(buf[b:], %s%s[i])", prefix, f.ListName)
 	c.Putln("b += 4")
@@ -200,16 +197,24 @@ func (f *ValueField) Write(c *Context, prefix string) {
 
 // Switch field
 func (f *SwitchField) Define(c *Context) {
-	c.Putln("// switch field: %s (%s)", f.Name, f.Expr)
+	c.Putln("%s []uint32", f.Name)
-	panic("todo")
 }
 
 func (f *SwitchField) Read(c *Context, prefix string) {
-	c.Putln("// reading switch field: %s (%s)", f.Name, f.Expr)
+	c.Putln("")
-	panic("todo")
+	c.Putln("%s%s = make([]uint32, %s)",
+		prefix, f.Name, f.ListLength().Reduce(prefix))
+	c.Putln("for i := 0; i < %s; i++ {", f.ListLength().Reduce(prefix))
+	c.Putln("%s%s[i] = xgb.Get32(buf[b:])", prefix, f.Name)
+	c.Putln("b += 4")
+	c.Putln("}")
+	c.Putln("b = xgb.Pad(b)")
 }
 
 func (f *SwitchField) Write(c *Context, prefix string) {
-	c.Putln("// writing switch field: %s (%s)", f.Name, f.Expr)
+	c.Putln("for i := 0; i < %s; i++ {", f.ListLength().Reduce(prefix))
-	panic("todo")
+	c.Putln("xgb.Put32(buf[b:], %s%s[i])", prefix, f.Name)
+	c.Putln("b += 4")
+	c.Putln("}")
+	c.Putln("b = xgb.Pad(b)")
 }

nexgb/xgbgen/go_request_reply.go

@@ -205,10 +205,7 @@ func (r *Request) ParamNames() string {
 	for _, field := range r.Fields {
 		switch f := field.(type) {
 		case *ValueField:
-			// mofos...
-			if r.SrcName() != "ConfigureWindow" {
 			names = append(names, f.MaskName)
-			}
 			names = append(names, f.ListName)
 		case *PadField:
 			continue
@@ -226,17 +223,16 @@ func (r *Request) ParamNameTypes() string {
 	for _, field := range r.Fields {
 		switch f := field.(type) {
 		case *ValueField:
-			// mofos...
-			if r.SrcName() != "ConfigureWindow" {
 			nameTypes = append(nameTypes,
 				fmt.Sprintf("%s %s", f.MaskName, f.MaskType.SrcName()))
-			}
 			nameTypes = append(nameTypes,
 				fmt.Sprintf("%s []uint32", f.ListName))
 		case *PadField:
 			continue
 		case *ExprField:
 			continue
+		case *RequiredStartAlign:
+			continue
 		default:
 			nameTypes = append(nameTypes,
 				fmt.Sprintf("%s %s", field.SrcName(), field.SrcType()))

nexgb/xgbgen/request_reply.go

@@ -105,17 +105,15 @@ func (r *Request) Size(c *Context) Size {
 	}
 
 	for _, field := range r.Fields {
-		switch field.(type) {
+		switch field := field.(type) {
 		case *LocalField: // local fields don't go over the wire
 			continue
 		case *SingleField:
-			// mofos!!!
+			fsz := field.Size()
-			if r.SrcName() == "ConfigureWindow" &&
+			if _, isstruct := field.Type.(*Struct); isstruct {
-				field.SrcName() == "ValueMask" {
+				fsz.Expression = fsz.Expression.Specialize(field.SrcName())
-
-				continue
 			}
-			size = size.Add(field.Size())
+			size = size.Add(fsz)
 		default:
 			size = size.Add(field.Size())
 		}

nexgb/xgbgen/translation.go

@@ -325,12 +325,14 @@ func (x *XMLField) Translate(parent interface{}) Field {
 	case "pad":
 		return &PadField{
 			Bytes: x.Bytes,
+			Align: x.Align,
 		}
 	case "field":
-		return &SingleField{
+		s := &SingleField{
 			xmlName: x.Name,
 			Type:    newTranslation(x.Type),
 		}
+		return s
 	case "list":
 		return &ListField{
 			xmlName:    x.Name,
@@ -365,6 +367,8 @@ func (x *XMLField) Translate(parent interface{}) Field {
 			swtch.Bitcases[i] = bitcase.Translate()
 		}
 		return swtch
+	case "required_start_align":
+		return &RequiredStartAlign{}
 	}
 
 	log.Panicf("Unrecognized field element: %s", x.XMLName.Local)

nexgb/xgbgen/xml_fields.go

@@ -10,6 +10,7 @@ type XMLField struct {
 
 	// For 'pad' element
 	Bytes uint `xml:"bytes,attr"`
+	Align uint16 `xml:"align,attr"`
 
 	// For 'field', 'list', 'localfield', 'exprfield' and 'switch' elements.
 	Name string `xml:"name,attr"`