Add Go frontend, libgo library, and Go testsuite.

gcc/:
	* gcc.c (default_compilers): Add entry for ".go".
	* common.opt: Add -static-libgo as a driver option.
	* doc/install.texi (Configuration): Mention libgo as an option for
	--enable-shared.  Mention go as an option for --enable-languages.
	* doc/invoke.texi (Overall Options): Mention .go as a file name
	suffix.  Mention go as a -x option.
	* doc/frontends.texi (G++ and GCC): Mention Go as a supported
	language.
	* doc/sourcebuild.texi (Top Level): Mention libgo.
	* doc/standards.texi (Standards): Add section on Go language.
	Move references for other languages into their own section.
	* doc/contrib.texi (Contributors): Mention that I contributed the
	Go frontend.
gcc/testsuite/:
	* lib/go.exp: New file.
	* lib/go-dg.exp: New file.
	* lib/go-torture.exp: New file.
	* lib/target-supports.exp (check_compile): Match // Go.

From-SVN: r167407

1 files changed, 493 insertions, 0 deletions

diff --git a/libgo/go/xml/read.go b/libgo/go/xml/read.go
new file mode 100644
index 0000000..bbceda6
--- /dev/null
+++ b/libgo/go/xml/read.go
@@ -0,0 +1,493 @@
+// Copyright 2009 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 xml
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"reflect"
+	"strconv"
+	"strings"
+	"unicode"
+	"utf8"
+)
+
+// BUG(rsc): Mapping between XML elements and data structures is inherently flawed:
+// an XML element is an order-dependent collection of anonymous
+// values, while a data structure is an order-independent collection
+// of named values.
+// See package json for a textual representation more suitable
+// to data structures.
+
+// Unmarshal parses an XML element from r and uses the
+// reflect library to fill in an arbitrary struct, slice, or string
+// pointed at by val.  Well-formed data that does not fit
+// into val is discarded.
+//
+// For example, given these definitions:
+//
+//	type Email struct {
+//		Where string "attr"
+//		Addr  string
+//	}
+//
+//	type Result struct {
+//		XMLName xml.Name "result"
+//		Name	string
+//		Phone	string
+//		Email	[]Email
+//	}
+//
+//	result := Result{Name: "name", Phone: "phone", Email: nil}
+//
+// unmarshalling the XML input
+//
+//	<result>
+//		<email where="home">
+//			<addr>gre@example.com</addr>
+//		</email>
+//		<email where='work'>
+//			<addr>gre@work.com</addr>
+//		</email>
+//		<name>Grace R. Emlin</name>
+//		<address>123 Main Street</address>
+//	</result>
+//
+// via Unmarshal(r, &result) is equivalent to assigning
+//
+//	r = Result{xml.Name{"", "result"},
+//		"Grace R. Emlin", // name
+//		"phone",	  // no phone given
+//		[]Email{
+//			Email{"home", "gre@example.com"},
+//			Email{"work", "gre@work.com"},
+//		},
+//	}
+//
+// Note that the field r.Phone has not been modified and
+// that the XML <address> element was discarded.
+//
+// Because Unmarshal uses the reflect package, it can only
+// assign to upper case fields.  Unmarshal uses a case-insensitive
+// comparison to match XML element names to struct field names.
+//
+// Unmarshal maps an XML element to a struct using the following rules:
+//
+//   * If the struct has a field of type []byte or string with tag "innerxml",
+//      Unmarshal accumulates the raw XML nested inside the element
+//      in that field.  The rest of the rules still apply.
+//
+//   * If the struct has a field named XMLName of type xml.Name,
+//      Unmarshal records the element name in that field.
+//
+//   * If the XMLName field has an associated tag string of the form
+//      "tag" or "namespace-URL tag", the XML element must have
+//      the given tag (and, optionally, name space) or else Unmarshal
+//      returns an error.
+//
+//   * If the XML element has an attribute whose name matches a
+//      struct field of type string with tag "attr", Unmarshal records
+//      the attribute value in that field.
+//
+//   * If the XML element contains character data, that data is
+//      accumulated in the first struct field that has tag "chardata".
+//      The struct field may have type []byte or string.
+//      If there is no such field, the character data is discarded.
+//
+//   * If the XML element contains a sub-element whose name
+//      matches a struct field whose tag is neither "attr" nor "chardata",
+//      Unmarshal maps the sub-element to that struct field.
+//      Otherwise, if the struct has a field named Any, unmarshal
+//      maps the sub-element to that struct field.
+//
+// Unmarshal maps an XML element to a string or []byte by saving the
+// concatenation of that elements character data in the string or []byte.
+//
+// Unmarshal maps an XML element to a slice by extending the length
+// of the slice and mapping the element to the newly created value.
+//
+// Unmarshal maps an XML element to a bool by setting it to the boolean
+// value represented by the string.
+//
+// Unmarshal maps an XML element to an integer or floating-point
+// field by setting the field to the result of interpreting the string
+// value in decimal.  There is no check for overflow.
+//
+// Unmarshal maps an XML element to an xml.Name by recording the
+// element name.
+//
+// Unmarshal maps an XML element to a pointer by setting the pointer
+// to a freshly allocated value and then mapping the element to that value.
+//
+func Unmarshal(r io.Reader, val interface{}) os.Error {
+	v, ok := reflect.NewValue(val).(*reflect.PtrValue)
+	if !ok {
+		return os.NewError("non-pointer passed to Unmarshal")
+	}
+	p := NewParser(r)
+	elem := v.Elem()
+	err := p.unmarshal(elem, nil)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// An UnmarshalError represents an error in the unmarshalling process.
+type UnmarshalError string
+
+func (e UnmarshalError) String() string { return string(e) }
+
+// The Parser's Unmarshal method is like xml.Unmarshal
+// except that it can be passed a pointer to the initial start element,
+// useful when a client reads some raw XML tokens itself
+// but also defers to Unmarshal for some elements.
+// Passing a nil start element indicates that Unmarshal should
+// read the token stream to find the start element.
+func (p *Parser) Unmarshal(val interface{}, start *StartElement) os.Error {
+	v, ok := reflect.NewValue(val).(*reflect.PtrValue)
+	if !ok {
+		return os.NewError("non-pointer passed to Unmarshal")
+	}
+	return p.unmarshal(v.Elem(), start)
+}
+
+// fieldName strips invalid characters from an XML name
+// to create a valid Go struct name.  It also converts the
+// name to lower case letters.
+func fieldName(original string) string {
+
+	var i int
+	//remove leading underscores
+	for i = 0; i < len(original) && original[i] == '_'; i++ {
+	}
+
+	return strings.Map(
+		func(x int) int {
+			if x == '_' || unicode.IsDigit(x) || unicode.IsLetter(x) {
+				return unicode.ToLower(x)
+			}
+			return -1
+		},
+		original[i:])
+}
+
+// Unmarshal a single XML element into val.
+func (p *Parser) unmarshal(val reflect.Value, start *StartElement) os.Error {
+	// Find start element if we need it.
+	if start == nil {
+		for {
+			tok, err := p.Token()
+			if err != nil {
+				return err
+			}
+			if t, ok := tok.(StartElement); ok {
+				start = &t
+				break
+			}
+		}
+	}
+
+	if pv, ok := val.(*reflect.PtrValue); ok {
+		if pv.Get() == 0 {
+			zv := reflect.MakeZero(pv.Type().(*reflect.PtrType).Elem())
+			pv.PointTo(zv)
+			val = zv
+		} else {
+			val = pv.Elem()
+		}
+	}
+
+	var (
+		data         []byte
+		saveData     reflect.Value
+		comment      []byte
+		saveComment  reflect.Value
+		saveXML      reflect.Value
+		saveXMLIndex int
+		saveXMLData  []byte
+		sv           *reflect.StructValue
+		styp         *reflect.StructType
+	)
+	switch v := val.(type) {
+	default:
+		return os.ErrorString("unknown type " + v.Type().String())
+
+	case *reflect.SliceValue:
+		typ := v.Type().(*reflect.SliceType)
+		if typ.Elem().Kind() == reflect.Uint8 {
+			// []byte
+			saveData = v
+			break
+		}
+
+		// Slice of element values.
+		// Grow slice.
+		n := v.Len()
+		if n >= v.Cap() {
+			ncap := 2 * n
+			if ncap < 4 {
+				ncap = 4
+			}
+			new := reflect.MakeSlice(typ, n, ncap)
+			reflect.ArrayCopy(new, v)
+			v.Set(new)
+		}
+		v.SetLen(n + 1)
+
+		// Recur to read element into slice.
+		if err := p.unmarshal(v.Elem(n), start); err != nil {
+			v.SetLen(n)
+			return err
+		}
+		return nil
+
+	case *reflect.BoolValue, *reflect.FloatValue, *reflect.IntValue, *reflect.UintValue, *reflect.StringValue:
+		saveData = v
+
+	case *reflect.StructValue:
+		if _, ok := v.Interface().(Name); ok {
+			v.Set(reflect.NewValue(start.Name).(*reflect.StructValue))
+			break
+		}
+
+		sv = v
+		typ := sv.Type().(*reflect.StructType)
+		styp = typ
+		// Assign name.
+		if f, ok := typ.FieldByName("XMLName"); ok {
+			// Validate element name.
+			if f.Tag != "" {
+				tag := f.Tag
+				ns := ""
+				i := strings.LastIndex(tag, " ")
+				if i >= 0 {
+					ns, tag = tag[0:i], tag[i+1:]
+				}
+				if tag != start.Name.Local {
+					return UnmarshalError("expected element type <" + tag + "> but have <" + start.Name.Local + ">")
+				}
+				if ns != "" && ns != start.Name.Space {
+					e := "expected element <" + tag + "> in name space " + ns + " but have "
+					if start.Name.Space == "" {
+						e += "no name space"
+					} else {
+						e += start.Name.Space
+					}
+					return UnmarshalError(e)
+				}
+			}
+
+			// Save
+			v := sv.FieldByIndex(f.Index)
+			if _, ok := v.Interface().(Name); !ok {
+				return UnmarshalError(sv.Type().String() + " field XMLName does not have type xml.Name")
+			}
+			v.(*reflect.StructValue).Set(reflect.NewValue(start.Name).(*reflect.StructValue))
+		}
+
+		// Assign attributes.
+		// Also, determine whether we need to save character data or comments.
+		for i, n := 0, typ.NumField(); i < n; i++ {
+			f := typ.Field(i)
+			switch f.Tag {
+			case "attr":
+				strv, ok := sv.FieldByIndex(f.Index).(*reflect.StringValue)
+				if !ok {
+					return UnmarshalError(sv.Type().String() + " field " + f.Name + " has attr tag but is not type string")
+				}
+				// Look for attribute.
+				val := ""
+				k := strings.ToLower(f.Name)
+				for _, a := range start.Attr {
+					if fieldName(a.Name.Local) == k {
+						val = a.Value
+						break
+					}
+				}
+				strv.Set(val)
+
+			case "comment":
+				if saveComment == nil {
+					saveComment = sv.FieldByIndex(f.Index)
+				}
+
+			case "chardata":
+				if saveData == nil {
+					saveData = sv.FieldByIndex(f.Index)
+				}
+
+			case "innerxml":
+				if saveXML == nil {
+					saveXML = sv.FieldByIndex(f.Index)
+					if p.saved == nil {
+						saveXMLIndex = 0
+						p.saved = new(bytes.Buffer)
+					} else {
+						saveXMLIndex = p.savedOffset()
+					}
+				}
+			}
+		}
+	}
+
+	// Find end element.
+	// Process sub-elements along the way.
+Loop:
+	for {
+		var savedOffset int
+		if saveXML != nil {
+			savedOffset = p.savedOffset()
+		}
+		tok, err := p.Token()
+		if err != nil {
+			return err
+		}
+		switch t := tok.(type) {
+		case StartElement:
+			// Sub-element.
+			// Look up by tag name.
+			if sv != nil {
+				k := fieldName(t.Name.Local)
+				match := func(s string) bool {
+					// check if the name matches ignoring case
+					if strings.ToLower(s) != strings.ToLower(k) {
+						return false
+					}
+					// now check that it's public
+					c, _ := utf8.DecodeRuneInString(s)
+					return unicode.IsUpper(c)
+				}
+
+				f, found := styp.FieldByNameFunc(match)
+				if !found { // fall back to mop-up field named "Any"
+					f, found = styp.FieldByName("Any")
+				}
+				if found {
+					if err := p.unmarshal(sv.FieldByIndex(f.Index), &t); err != nil {
+						return err
+					}
+					continue Loop
+				}
+			}
+			// Not saving sub-element but still have to skip over it.
+			if err := p.Skip(); err != nil {
+				return err
+			}
+
+		case EndElement:
+			if saveXML != nil {
+				saveXMLData = p.saved.Bytes()[saveXMLIndex:savedOffset]
+				if saveXMLIndex == 0 {
+					p.saved = nil
+				}
+			}
+			break Loop
+
+		case CharData:
+			if saveData != nil {
+				data = bytes.Add(data, t)
+			}
+
+		case Comment:
+			if saveComment != nil {
+				comment = bytes.Add(comment, t)
+			}
+		}
+	}
+
+	var err os.Error
+	// Helper functions for integer and unsigned integer conversions
+	var itmp int64
+	getInt64 := func() bool {
+		itmp, err = strconv.Atoi64(string(data))
+		// TODO: should check sizes
+		return err == nil
+	}
+	var utmp uint64
+	getUint64 := func() bool {
+		utmp, err = strconv.Atoui64(string(data))
+		// TODO: check for overflow?
+		return err == nil
+	}
+	var ftmp float64
+	getFloat64 := func() bool {
+		ftmp, err = strconv.Atof64(string(data))
+		// TODO: check for overflow?
+		return err == nil
+	}
+
+	// Save accumulated data and comments
+	switch t := saveData.(type) {
+	case nil:
+		// Probably a comment, handled below
+	default:
+		return os.ErrorString("cannot happen: unknown type " + t.Type().String())
+	case *reflect.IntValue:
+		if !getInt64() {
+			return err
+		}
+		t.Set(itmp)
+	case *reflect.UintValue:
+		if !getUint64() {
+			return err
+		}
+		t.Set(utmp)
+	case *reflect.FloatValue:
+		if !getFloat64() {
+			return err
+		}
+		t.Set(ftmp)
+	case *reflect.BoolValue:
+		value, err := strconv.Atob(strings.TrimSpace(string(data)))
+		if err != nil {
+			return err
+		}
+		t.Set(value)
+	case *reflect.StringValue:
+		t.Set(string(data))
+	case *reflect.SliceValue:
+		t.Set(reflect.NewValue(data).(*reflect.SliceValue))
+	}
+
+	switch t := saveComment.(type) {
+	case *reflect.StringValue:
+		t.Set(string(comment))
+	case *reflect.SliceValue:
+		t.Set(reflect.NewValue(comment).(*reflect.SliceValue))
+	}
+
+	switch t := saveXML.(type) {
+	case *reflect.StringValue:
+		t.Set(string(saveXMLData))
+	case *reflect.SliceValue:
+		t.Set(reflect.NewValue(saveXMLData).(*reflect.SliceValue))
+	}
+
+	return nil
+}
+
+// Have already read a start element.
+// Read tokens until we find the end element.
+// Token is taking care of making sure the
+// end element matches the start element we saw.
+func (p *Parser) Skip() os.Error {
+	for {
+		tok, err := p.Token()
+		if err != nil {
+			return err
+		}
+		switch t := tok.(type) {
+		case StartElement:
+			if err := p.Skip(); err != nil {
+				return err
+			}
+		case EndElement:
+			return nil
+		}
+	}
+	panic("unreachable")
+}