xml: add line numbers to syntax errors.

R=rsc
CC=golang-dev
https://golang.org/cl/699041

diff --git a/src/pkg/xml/xml.go b/src/pkg/xml/xml.go
index 0d4729dda4c579193eff9a3e2a257c971156fe0d..796dce5828c3407b3b613e6a32bbc7ababdb83cb 100644 (file)
--- a/src/pkg/xml/xml.go
+++ b/src/pkg/xml/xml.go
@@ -12,7 +12,6 @@ package xml
 
 // TODO(rsc):
 //     Test error handling.
-//     Expose parser line number in errors.
 
 import (
        "bufio"
@@ -26,9 +25,14 @@ import (
 )
 
 // A SyntaxError represents a syntax error in the XML input stream.
-type SyntaxError string
+type SyntaxError struct {
+       Msg  string
+       Line int
+}
 
-func (e SyntaxError) String() string { return "XML syntax error: " + string(e) }
+func (e *SyntaxError) String() string {
+       return "XML syntax error on line " + strconv.Itoa(e.Line) + ": " + e.Msg
+}
 
 // A Name represents an XML name (Local) annotated
 // with a name space identifier (Space).
@@ -344,6 +348,11 @@ func (p *Parser) pushNs(local string, url string, ok bool) {
        s.ok = ok
 }
 
+// Creates a SyntaxError with the current line number.
+func (p *Parser) syntaxError(msg string) os.Error {
+       return &SyntaxError{Msg: msg, Line: p.line}
+}
+
 // Record that we are ending an element with the given name.
 // The name must match the record at the top of the stack,
 // which must be a pushElement record.
@@ -355,7 +364,7 @@ func (p *Parser) popElement(t *EndElement) bool {
        name := t.Name
        switch {
        case s == nil || s.kind != stkStart:
-               p.err = SyntaxError("unexpected end element </" + name.Local + ">")
+               p.err = p.syntaxError("unexpected end element </" + name.Local + ">")
                return false
        case s.name.Local != name.Local:
                if !p.Strict {
@@ -364,10 +373,10 @@ func (p *Parser) popElement(t *EndElement) bool {
                        t.Name = s.name
                        return true
                }
-               p.err = SyntaxError("element <" + s.name.Local + "> closed by </" + name.Local + ">")
+               p.err = p.syntaxError("element <" + s.name.Local + "> closed by </" + name.Local + ">")
                return false
        case s.name.Space != name.Space:
-               p.err = SyntaxError("element <" + s.name.Local + "> in space " + s.name.Space +
+               p.err = p.syntaxError("element <" + s.name.Local + "> in space " + s.name.Space +
                        "closed by </" + name.Local + "> in space " + name.Space)
                return false
        }
@@ -442,7 +451,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                var name Name
                if name, ok = p.nsname(); !ok {
                        if p.err == nil {
-                               p.err = SyntaxError("expected element name after </")
+                               p.err = p.syntaxError("expected element name after </")
                        }
                        return nil, p.err
                }
@@ -451,7 +460,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                        return nil, p.err
                }
                if b != '>' {
-                       p.err = SyntaxError("invalid characters between </" + name.Local + " and >")
+                       p.err = p.syntaxError("invalid characters between </" + name.Local + " and >")
                        return nil, p.err
                }
                return EndElement{name}, nil
@@ -463,7 +472,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                var target string
                if target, ok = p.name(); !ok {
                        if p.err == nil {
-                               p.err = SyntaxError("expected target name after <?")
+                               p.err = p.syntaxError("expected target name after <?")
                        }
                        return nil, p.err
                }
@@ -496,7 +505,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                                return nil, p.err
                        }
                        if b != '-' {
-                               p.err = SyntaxError("invalid sequence <!- not part of <!--")
+                               p.err = p.syntaxError("invalid sequence <!- not part of <!--")
                                return nil, p.err
                        }
                        // Look for terminator.
@@ -523,7 +532,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                                        return nil, p.err
                                }
                                if b != "CDATA["[i] {
-                                       p.err = SyntaxError("invalid <![ sequence")
+                                       p.err = p.syntaxError("invalid <![ sequence")
                                        return nil, p.err
                                }
                        }
@@ -561,7 +570,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
        )
        if name, ok = p.nsname(); !ok {
                if p.err == nil {
-                       p.err = SyntaxError("expected element name after <")
+                       p.err = p.syntaxError("expected element name after <")
                }
                return nil, p.err
        }
@@ -578,7 +587,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                                return nil, p.err
                        }
                        if b != '>' {
-                               p.err = SyntaxError("expected /> in element")
+                               p.err = p.syntaxError("expected /> in element")
                                return nil, p.err
                        }
                        break
@@ -600,7 +609,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                a := &attr[n]
                if a.Name, ok = p.nsname(); !ok {
                        if p.err == nil {
-                               p.err = SyntaxError("expected attribute name in element")
+                               p.err = p.syntaxError("expected attribute name in element")
                        }
                        return nil, p.err
                }
@@ -609,7 +618,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
                        return nil, p.err
                }
                if b != '=' {
-                       p.err = SyntaxError("attribute name without = in element")
+                       p.err = p.syntaxError("attribute name without = in element")
                        return nil, p.err
                }
                p.space()
@@ -638,7 +647,7 @@ func (p *Parser) attrval() []byte {
        }
        // Handle unquoted attribute values for strict parsers
        if p.Strict {
-               p.err = SyntaxError("unquoted or missing attribute value in element")
+               p.err = p.syntaxError("unquoted or missing attribute value in element")
                return nil
        }
        // Handle unquoted attribute values for unstrict parsers
@@ -707,7 +716,7 @@ func (p *Parser) getc() (b byte, ok bool) {
 func (p *Parser) mustgetc() (b byte, ok bool) {
        if b, ok = p.getc(); !ok {
                if p.err == os.EOF {
-                       p.err = SyntaxError("unexpected EOF")
+                       p.err = p.syntaxError("unexpected EOF")
                }
        }
        return
@@ -751,14 +760,14 @@ Input:
                                trunc = 2
                                break Input
                        }
-                       p.err = SyntaxError("unescaped ]]> not in CDATA section")
+                       p.err = p.syntaxError("unescaped ]]> not in CDATA section")
                        return nil
                }
 
                // Stop reading text if we see a <.
                if b == '<' && !cdata {
                        if quote >= 0 {
-                               p.err = SyntaxError("unescaped < inside quoted string")
+                               p.err = p.syntaxError("unescaped < inside quoted string")
                                return nil
                        }
                        p.ungetc('<')
@@ -779,7 +788,7 @@ Input:
                                p.tmp[i], p.err = p.r.ReadByte()
                                if p.err != nil {
                                        if p.err == os.EOF {
-                                               p.err = SyntaxError("unexpected EOF")
+                                               p.err = p.syntaxError("unexpected EOF")
                                        }
                                        return nil
                                }
@@ -804,7 +813,7 @@ Input:
                                        p.buf.Write(p.tmp[0:i])
                                        continue Input
                                }
-                               p.err = SyntaxError("character entity expression &" + s + "... too long")
+                               p.err = p.syntaxError("character entity expression &" + s + "... too long")
                                return nil
                        }
                        var haveText bool
@@ -836,7 +845,7 @@ Input:
                                        p.buf.Write(p.tmp[0:i])
                                        continue Input
                                }
-                               p.err = SyntaxError("invalid character entity &" + s + ";")
+                               p.err = p.syntaxError("invalid character entity &" + s + ";")
                                return nil
                        }
                        p.buf.Write([]byte(text))
@@ -913,7 +922,7 @@ func (p *Parser) name() (s string, ok bool) {
        s = p.buf.String()
        for i, c := range s {
                if !unicode.Is(first, c) && (i == 0 || !unicode.Is(second, c)) {
-                       p.err = SyntaxError("invalid XML name: " + s)
+                       p.err = p.syntaxError("invalid XML name: " + s)
                        return "", false
                }
        }

diff --git a/src/pkg/xml/xml_test.go b/src/pkg/xml/xml_test.go
index 37538cbe9e29c3167472d26ba71f57a1ffa42630..dab35df7319ab32bb114a68be4201e323586ad5f 100644 (file)
--- a/src/pkg/xml/xml_test.go
+++ b/src/pkg/xml/xml_test.go
@@ -209,7 +209,7 @@ func TestSyntax(t *testing.T) {
                var err os.Error
                for _, err = p.Token(); err == nil; _, err = p.Token() {
                }
-               if _, ok := err.(SyntaxError); !ok {
+               if _, ok := err.(*SyntaxError); !ok {
                        t.Fatalf(`xmlInput "%s": expected SyntaxError not received`, xmlInput[i])
                }
        }
@@ -314,7 +314,7 @@ func TestUnquotedAttrs(t *testing.T) {
        p := NewParser(StringReader(data))
        p.Strict = false
        token, err := p.Token()
-       if _, ok := err.(SyntaxError); ok {
+       if _, ok := err.(*SyntaxError); ok {
                t.Errorf("Unexpected error: %v", err)
        }
        if token.(StartElement).Name.Local != "tag" {
@@ -354,3 +354,18 @@ func TestCopyTokenStartElement(t *testing.T) {
                t.Error("CopyToken(CharData) uses same buffer.")
        }
 }
+
+func TestSyntaxErrorLineNum(t *testing.T) {
+       testInput := "<P>Foo<P>\n\n<P>Bar</>\n"
+       p := NewParser(StringReader(testInput))
+       var err os.Error
+       for _, err = p.Token(); err == nil; _, err = p.Token() {
+       }
+       synerr, ok := err.(*SyntaxError)
+       if !ok {
+               t.Error("Expected SyntaxError.")
+       }
+       if synerr.Line != 3 {
+               t.Error("SyntaxError didn't have correct line number.")
+       }
+}