Hide builder.parser.Directive internals

Signed-off-by: Daniel Nephin <dnephin@docker.com>

builder/dockerfile/builder.go

@@ -62,7 +62,7 @@ type Builder struct {
 	disableCommit bool
 	cacheBusted   bool
 	buildArgs     *buildArgs
-	directive     parser.Directive
+	directive     *parser.Directive
 
 	imageCache builder.ImageCache
 	from       builder.Image
@@ -122,14 +122,9 @@ func NewBuilder(clientCtx context.Context, config *types.ImageBuildOptions, back
 		runConfig:     new(container.Config),
 		tmpContainers: map[string]struct{}{},
 		buildArgs:     newBuildArgs(config.BuildArgs),
-		directive: parser.Directive{
-			EscapeSeen:           false,
-			LookingForDirectives: true,
-		},
+		directive:     parser.NewDefaultDirective(),
 	}
 	b.imageContexts = &imageContexts{b: b}
-
-	parser.SetEscapeToken(parser.DefaultEscapeToken, &b.directive) // Assume the default token for escape
 	return b, nil
 }
 
@@ -325,7 +320,7 @@ func BuildFromConfig(config *container.Config, changes []string) (*container.Con
 		return nil, err
 	}
 
-	ast, err := parser.Parse(bytes.NewBufferString(strings.Join(changes, "\n")), &b.directive)
+	ast, err := parser.Parse(bytes.NewBufferString(strings.Join(changes, "\n")), b.directive)
 	if err != nil {
 		return nil, err
 	}

builder/dockerfile/builder_test.go

@@ -10,9 +10,8 @@ import (
 
 func TestAddNodesForLabelOption(t *testing.T) {
 	dockerfile := "FROM scratch"
-	d := parser.Directive{}
-	parser.SetEscapeToken(parser.DefaultEscapeToken, &d)
-	nodes, err := parser.Parse(strings.NewReader(dockerfile), &d)
+	d := parser.NewDefaultDirective()
+	nodes, err := parser.Parse(strings.NewReader(dockerfile), d)
 	assert.NilError(t, err)
 
 	labels := map[string]string{

builder/dockerfile/dispatchers.go

@@ -200,7 +200,7 @@ func from(b *Builder, args []string, attributes map[string]bool, original string
 		substituionArgs = append(substituionArgs, key+"="+value)
 	}
 
-	name, err := ProcessWord(args[0], substituionArgs, b.directive.EscapeToken)
+	name, err := ProcessWord(args[0], substituionArgs, b.directive.EscapeToken())
 	if err != nil {
 		return err
 	}

builder/dockerfile/dispatchers_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/strslice"
 	"github.com/docker/docker/builder"
+	"github.com/docker/docker/builder/dockerfile/parser"
 	"github.com/docker/docker/pkg/testutil/assert"
 	"github.com/docker/go-connections/nat"
 )
@@ -204,6 +205,7 @@ func newBuilderWithMockBackend() *Builder {
 		options:   &types.ImageBuildOptions{},
 		docker:    &MockBackend{},
 		buildArgs: newBuildArgs(make(map[string]*string)),
+		directive: parser.NewDefaultDirective(),
 	}
 	b.imageContexts = &imageContexts{b: b}
 	return b

builder/dockerfile/evaluator.go

@@ -180,7 +180,7 @@ func (b *Builder) evaluateEnv(cmd string, str string, envs []string) ([]string,
 			return []string{word}, err
 		}
 	}
-	return processFunc(str, envs, b.directive.EscapeToken)
+	return processFunc(str, envs, b.directive.EscapeToken())
 }
 
 // buildArgsWithoutConfigEnv returns a list of key=value pairs for all the build

builder/dockerfile/evaluator_test.go

@@ -171,9 +171,7 @@ func executeTestCase(t *testing.T, testCase dispatchTestCase) {
 	}()
 
 	r := strings.NewReader(testCase.dockerfile)
-	d := parser.Directive{}
-	parser.SetEscapeToken(parser.DefaultEscapeToken, &d)
-	n, err := parser.Parse(r, &d)
+	n, err := parser.Parse(r, parser.NewDefaultDirective())
 
 	if err != nil {
 		t.Fatalf("Error when parsing Dockerfile: %s", err)
@@ -190,6 +188,7 @@ func executeTestCase(t *testing.T, testCase dispatchTestCase) {
 		Stdout:    ioutil.Discard,
 		context:   context,
 		buildArgs: newBuildArgs(options.BuildArgs),
+		directive: parser.NewDefaultDirective(),
 	}
 
 	err = b.dispatch(0, len(n.Children), n.Children[0])

builder/dockerfile/internals.go

@@ -462,7 +462,7 @@ func (b *Builder) processImageFrom(img builder.Image) error {
 
 	// parse the ONBUILD triggers by invoking the parser
 	for _, step := range onBuildTriggers {
-		ast, err := parser.Parse(strings.NewReader(step), &b.directive)
+		ast, err := parser.Parse(strings.NewReader(step), b.directive)
 		if err != nil {
 			return err
 		}
@@ -702,5 +702,5 @@ func (b *Builder) parseDockerfile() (*parser.Node, error) {
 			return nil, fmt.Errorf("The Dockerfile (%s) cannot be empty", b.options.Dockerfile)
 		}
 	}
-	return parser.Parse(f, &b.directive)
+	return parser.Parse(f, b.directive)
 }

builder/dockerfile/parser/dumper/main.go

@@ -23,10 +23,8 @@ func main() {
 		}
 		defer f.Close()
 
-		d := parser.Directive{LookingForDirectives: true}
-		parser.SetEscapeToken(parser.DefaultEscapeToken, &d)
-
-		ast, err := parser.Parse(f, &d)
+		d := parser.NewDefaultDirective()
+		ast, err := parser.Parse(f, d)
 		if err != nil {
 			panic(err)
 		} else {

builder/dockerfile/parser/json_test.go

@@ -29,7 +29,7 @@ var validJSONArraysOfStrings = map[string][]string{
 func TestJSONArraysOfStrings(t *testing.T) {
 	for json, expected := range validJSONArraysOfStrings {
 		d := Directive{}
-		SetEscapeToken(DefaultEscapeToken, &d)
+		d.SetEscapeToken(DefaultEscapeToken)
 
 		if node, _, err := parseJSON(json, &d); err != nil {
 			t.Fatalf("%q should be a valid JSON array of strings, but wasn't! (err: %q)", json, err)
@@ -52,7 +52,7 @@ func TestJSONArraysOfStrings(t *testing.T) {
 	}
 	for _, json := range invalidJSONArraysOfStrings {
 		d := Directive{}
-		SetEscapeToken(DefaultEscapeToken, &d)
+		d.SetEscapeToken(DefaultEscapeToken)
 
 		if _, _, err := parseJSON(json, &d); err != errDockerfileNotStringArray {
 			t.Fatalf("%q should be an invalid JSON array of strings, but wasn't!", json)

builder/dockerfile/parser/line_parsers.go

@@ -103,7 +103,7 @@ func parseWords(rest string, d *Directive) []string {
 				blankOK = true
 				phase = inQuote
 			}
-			if ch == d.EscapeToken {
+			if ch == d.escapeToken {
 				if pos+chWidth == len(rest) {
 					continue // just skip an escape token at end of line
 				}
@@ -122,7 +122,7 @@ func parseWords(rest string, d *Directive) []string {
 				phase = inWord
 			}
 			// The escape token is special except for ' quotes - can't escape anything for '
-			if ch == d.EscapeToken && quote != '\'' {
+			if ch == d.escapeToken && quote != '\'' {
 				if pos+chWidth == len(rest) {
 					phase = inWord
 					continue // just skip the escape token at end

builder/dockerfile/parser/parser.go

@@ -62,15 +62,6 @@ func (node *Node) Dump() string {
 	return strings.TrimSpace(str)
 }
 
-// Directive is the structure used during a build run to hold the state of
-// parsing directives.
-type Directive struct {
-	EscapeToken           rune           // Current escape token
-	LineContinuationRegex *regexp.Regexp // Current line continuation regex
-	LookingForDirectives  bool           // Whether we are currently looking for directives
-	EscapeSeen            bool           // Whether the escape directive has been seen
-}
-
 var (
 	dispatch           map[string]func(string, *Directive) (*Node, map[string]bool, error)
 	tokenWhitespace    = regexp.MustCompile(`[\t\v\f\r ]+`)
@@ -81,16 +72,40 @@ var (
 // DefaultEscapeToken is the default escape token
 const DefaultEscapeToken = "\\"
 
+// Directive is the structure used during a build run to hold the state of
+// parsing directives.
+type Directive struct {
+	escapeToken           rune           // Current escape token
+	lineContinuationRegex *regexp.Regexp // Current line continuation regex
+	lookingForDirectives  bool           // Whether we are currently looking for directives
+	escapeSeen            bool           // Whether the escape directive has been seen
+}
+
 // SetEscapeToken sets the default token for escaping characters in a Dockerfile.
-func SetEscapeToken(s string, d *Directive) error {
+func (d *Directive) SetEscapeToken(s string) error {
 	if s != "`" && s != "\\" {
 		return fmt.Errorf("invalid ESCAPE '%s'. Must be ` or \\", s)
 	}
-	d.EscapeToken = rune(s[0])
-	d.LineContinuationRegex = regexp.MustCompile(`\` + s + `[ \t]*$`)
+	d.escapeToken = rune(s[0])
+	d.lineContinuationRegex = regexp.MustCompile(`\` + s + `[ \t]*$`)
 	return nil
 }
 
+// EscapeToken returns the escape token
+func (d *Directive) EscapeToken() rune {
+	return d.escapeToken
+}
+
+// NewDefaultDirective returns a new Directive with the default escapeToken token
+func NewDefaultDirective() *Directive {
+	directive := Directive{
+		escapeSeen:           false,
+		lookingForDirectives: true,
+	}
+	directive.SetEscapeToken(DefaultEscapeToken)
+	return &directive
+}
+
 func init() {
 	// Dispatch Table. see line_parsers.go for the parse functions.
 	// The command is parsed and mapped to the line parser. The line parser
@@ -123,18 +138,18 @@ func init() {
 // ParseLine parses a line and returns the remainder.
 func ParseLine(line string, d *Directive, ignoreCont bool) (string, *Node, error) {
 	if escapeFound, err := handleParserDirective(line, d); err != nil || escapeFound {
-		d.EscapeSeen = escapeFound
+		d.escapeSeen = escapeFound
 		return "", nil, err
 	}
 
-	d.LookingForDirectives = false
+	d.lookingForDirectives = false
 
 	if line = stripComments(line); line == "" {
 		return "", nil, nil
 	}
 
-	if !ignoreCont && d.LineContinuationRegex.MatchString(line) {
-		line = d.LineContinuationRegex.ReplaceAllString(line, "")
+	if !ignoreCont && d.lineContinuationRegex.MatchString(line) {
+		line = d.lineContinuationRegex.ReplaceAllString(line, "")
 		return line, nil, nil
 	}
 
@@ -170,22 +185,22 @@ func newNodeFromLine(line string, directive *Directive) (*Node, error) {
 	}, nil
 }
 
-// Handle the parser directive '# escape=<char>. Parser directives must precede
+// Handle the parser directive '# escapeToken=<char>. Parser directives must precede
 // any builder instruction or other comments, and cannot be repeated.
 func handleParserDirective(line string, d *Directive) (bool, error) {
-	if !d.LookingForDirectives {
+	if !d.lookingForDirectives {
 		return false, nil
 	}
 	tecMatch := tokenEscapeCommand.FindStringSubmatch(strings.ToLower(line))
 	if len(tecMatch) == 0 {
 		return false, nil
 	}
-	if d.EscapeSeen == true {
+	if d.escapeSeen == true {
 		return false, fmt.Errorf("only one escape parser directive can be used")
 	}
 	for i, n := range tokenEscapeCommand.SubexpNames() {
 		if n == "escapechar" {
-			if err := SetEscapeToken(tecMatch[i], d); err != nil {
+			if err := d.SetEscapeToken(tecMatch[i]); err != nil {
 				return false, err
 			}
 			return true, nil

builder/dockerfile/parser/parser_test.go

@@ -40,9 +40,7 @@ func TestTestNegative(t *testing.T) {
 		}
 		defer df.Close()
 
-		d := Directive{LookingForDirectives: true}
-		SetEscapeToken(DefaultEscapeToken, &d)
-		_, err = Parse(df, &d)
+		_, err = Parse(df, NewDefaultDirective())
 		if err == nil {
 			t.Fatalf("No error parsing broken dockerfile for %s", dir)
 		}
@@ -60,9 +58,7 @@ func TestTestData(t *testing.T) {
 		}
 		defer df.Close()
 
-		d := Directive{LookingForDirectives: true}
-		SetEscapeToken(DefaultEscapeToken, &d)
-		ast, err := Parse(df, &d)
+		ast, err := Parse(df, NewDefaultDirective())
 		if err != nil {
 			t.Fatalf("Error parsing %s's dockerfile: %v", dir, err)
 		}
@@ -122,9 +118,7 @@ func TestParseWords(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		d := Directive{LookingForDirectives: true}
-		SetEscapeToken(DefaultEscapeToken, &d)
-		words := parseWords(test["input"][0], &d)
+		words := parseWords(test["input"][0], NewDefaultDirective())
 		if len(words) != len(test["expect"]) {
 			t.Fatalf("length check failed. input: %v, expect: %q, output: %q", test["input"][0], test["expect"], words)
 		}
@@ -143,9 +137,7 @@ func TestLineInformation(t *testing.T) {
 	}
 	defer df.Close()
 
-	d := Directive{LookingForDirectives: true}
-	SetEscapeToken(DefaultEscapeToken, &d)
-	ast, err := Parse(df, &d)
+	ast, err := Parse(df, NewDefaultDirective())
 	if err != nil {
 		t.Fatalf("Error parsing dockerfile %s: %v", testFileLineInfo, err)
 	}