config: convert to config/lang

config/config.go

@@ -8,6 +8,8 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/hashicorp/terraform/config/lang"
+	"github.com/hashicorp/terraform/config/lang/ast"
 	"github.com/hashicorp/terraform/flatmap"
 	"github.com/hashicorp/terraform/helper/multierror"
 	"github.com/mitchellh/mapstructure"
@@ -169,7 +171,7 @@ func (c *Config) Validate() error {
 		}
 
 		interp := false
-		fn := func(i Interpolation) (string, error) {
+		fn := func(ast.Node) (string, error) {
 			interp = true
 			return "", nil
 		}
@@ -353,9 +355,18 @@ func (c *Config) Validate() error {
 			}
 		}
 
-		// Interpolate with a fixed number to verify that its a number
+		// Interpolate with a fixed number to verify that its a number.
-		r.RawCount.interpolate(func(Interpolation) (string, error) {
+		r.RawCount.interpolate(func(root ast.Node) (string, error) {
-			return "5", nil
+			// Execute the node but transform the AST so that it returns
+			// a fixed value of "5" for all interpolations.
+			var engine lang.Engine
+			out, _, err := engine.Execute(lang.FixedValueTransform(
+				root, &ast.LiteralNode{Value: "5", Type: ast.TypeString}))
+			if err != nil {
+				return "", err
+			}
+
+			return out.(string), nil
 		})
 		_, err := strconv.ParseInt(r.RawCount.Value().(string), 0, 0)
 		if err != nil {
@@ -465,20 +476,29 @@ func (c *Config) rawConfigs() map[string]*RawConfig {
 
 func (c *Config) validateVarContextFn(
 	source string, errs *[]error) interpolationWalkerContextFunc {
-	return func(loc reflectwalk.Location, i Interpolation) {
+	return func(loc reflectwalk.Location, node ast.Node) {
-		vi, ok := i.(*VariableInterpolation)
+		if loc == reflectwalk.SliceElem {
-		if !ok {
 			return
 		}
 
-		rv, ok := vi.Variable.(*ResourceVariable)
+		vars, err := DetectVariables(node)
-		if !ok {
+		if err != nil {
+			// Ignore it since this will be caught during parse. This
+			// actually probably should never happen by the time this
+			// is called, but its okay.
 			return
 		}
 
-		if rv.Multi && rv.Index == -1 && loc != reflectwalk.SliceElem {
+		for _, v := range vars {
-			*errs = append(*errs, fmt.Errorf(
+			rv, ok := v.(*ResourceVariable)
-				"%s: multi-variable must be in a slice", source))
+			if !ok {
+				return
+			}
+
+			if rv.Multi && rv.Index == -1 {
+				*errs = append(*errs, fmt.Errorf(
+					"%s: multi-variable must be in a slice", source))
+			}
 		}
 	}
 }

config/interpolate_walk.go

@@ -3,9 +3,10 @@ package config
 import (
 	"fmt"
 	"reflect"
-	"regexp"
 	"strings"
 
+	"github.com/hashicorp/terraform/config/lang"
+	"github.com/hashicorp/terraform/config/lang/ast"
 	"github.com/mitchellh/reflectwalk"
 )
 
@@ -14,10 +15,6 @@ import (
 // a value that a user is very unlikely to use (such as UUID).
 const InterpSplitDelim = `B780FFEC-B661-4EB8-9236-A01737AD98B6`
 
-// interpRegexp is a regexp that matches interpolations such as ${foo.bar}
-var interpRegexp *regexp.Regexp = regexp.MustCompile(
-	`(?i)(\$+)\{([\s*-.,\\/\(\):a-z0-9_"]+)\}`)
-
 // interpolationWalker implements interfaces for the reflectwalk package
 // (github.com/mitchellh/reflectwalk) that can be used to automatically
 // execute a callback for an interpolation.
@@ -50,7 +47,7 @@ type interpolationWalker struct {
 //
 // If Replace is set to false in interpolationWalker, then the replace
 // value can be anything as it will have no effect.
-type interpolationWalkerFunc func(Interpolation) (string, error)
+type interpolationWalkerFunc func(ast.Node) (string, error)
 
 // interpolationWalkerContextFunc is called by interpolationWalk if
 // ContextF is set. This receives both the interpolation and the location
@@ -58,7 +55,7 @@ type interpolationWalkerFunc func(Interpolation) (string, error)
 //
 // This callback can be used to validate the location of the interpolation
 // within the configuration.
-type interpolationWalkerContextFunc func(reflectwalk.Location, Interpolation)
+type interpolationWalkerContextFunc func(reflectwalk.Location, ast.Node)
 
 func (w *interpolationWalker) Enter(loc reflectwalk.Location) error {
 	w.loc = loc
@@ -121,76 +118,54 @@ func (w *interpolationWalker) Primitive(v reflect.Value) error {
 		return nil
 	}
 
-	// XXX: This can be a lot more efficient if we used a real
+	astRoot, err := lang.Parse(v.String())
-	// parser. A regexp is a hammer though that will get this working.
+	if err != nil {
+		return err
+	}
 
-	matches := interpRegexp.FindAllStringSubmatch(v.String(), -1)
+	// If the AST we got is just a literal string value, then we ignore it
-	if len(matches) == 0 {
+	if _, ok := astRoot.(*ast.LiteralNode); ok {
 		return nil
 	}
 
-	result := v.String()
+	if w.ContextF != nil {
-	for _, match := range matches {
+		w.ContextF(w.loc, astRoot)
-		dollars := len(match[1])
+	}
 
-		// If there are even amounts of dollar signs, then it is escaped
+	if w.F == nil {
-		if dollars%2 == 0 {
+		return nil
-			continue
+	}
-		}
 
-		// Interpolation found, instantiate it
+	replaceVal, err := w.F(astRoot)
-		key := match[2]
+	if err != nil {
-
+		return fmt.Errorf(
-		i, err := ExprParse(key)
+			"%s in:\n\n%s",
-		if err != nil {
+			err, v.String())
-			return err
-		}
-
-		if w.ContextF != nil {
-			w.ContextF(w.loc, i)
-		}
-
-		if w.F == nil {
-			continue
-		}
-
-		replaceVal, err := w.F(i)
-		if err != nil {
-			return fmt.Errorf(
-				"%s: %s",
-				key,
-				err)
-		}
-
-		if w.Replace {
-			// We need to determine if we need to remove this element
-			// if the result contains any "UnknownVariableValue" which is
-			// set if it is computed. This behavior is different if we're
-			// splitting (in a SliceElem) or not.
-			remove := false
-			if w.loc == reflectwalk.SliceElem {
-				parts := strings.Split(replaceVal, InterpSplitDelim)
-				for _, p := range parts {
-					if p == UnknownVariableValue {
-						remove = true
-						break
-					}
-				}
-			} else if replaceVal == UnknownVariableValue {
-				remove = true
-			}
-			if remove {
-				w.removeCurrent()
-				return nil
-			}
-
-			// Replace in our interpolation and continue on.
-			result = strings.Replace(result, match[0], replaceVal, -1)
-		}
 	}
 
 	if w.Replace {
-		resultVal := reflect.ValueOf(result)
+		// We need to determine if we need to remove this element
+		// if the result contains any "UnknownVariableValue" which is
+		// set if it is computed. This behavior is different if we're
+		// splitting (in a SliceElem) or not.
+		remove := false
+		if w.loc == reflectwalk.SliceElem {
+			parts := strings.Split(replaceVal, InterpSplitDelim)
+			for _, p := range parts {
+				if p == UnknownVariableValue {
+					remove = true
+					break
+				}
+			}
+		} else if replaceVal == UnknownVariableValue {
+			remove = true
+		}
+		if remove {
+			w.removeCurrent()
+			return nil
+		}
+
+		resultVal := reflect.ValueOf(replaceVal)
 		switch w.loc {
 		case reflectwalk.MapKey:
 			m := w.cs[len(w.cs)-1]

config/interpolate_walk_test.go

@@ -1,16 +1,18 @@
 package config
 
 import (
+	"fmt"
 	"reflect"
 	"testing"
 
+	"github.com/hashicorp/terraform/config/lang/ast"
 	"github.com/mitchellh/reflectwalk"
 )
 
 func TestInterpolationWalker_detect(t *testing.T) {
 	cases := []struct {
 		Input  interface{}
-		Result []Interpolation
+		Result []string
 	}{
 		{
 			Input: map[string]interface{}{
@@ -23,13 +25,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": "${var.foo}",
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&VariableInterpolation{
+				"Variable(var.foo)",
-					Variable: &UserVariable{
-						Name: "foo",
-						key:  "var.foo",
-					},
-				},
 			},
 		},
 
@@ -37,19 +34,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": "${aws_instance.foo.*.num}",
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&VariableInterpolation{
+				"Variable(aws_instance.foo.*.num)",
-					Variable: &ResourceVariable{
-						Type:  "aws_instance",
-						Name:  "foo",
-						Field: "num",
-
-						Multi: true,
-						Index: -1,
-
-						key: "aws_instance.foo.*.num",
-					},
-				},
 			},
 		},
 
@@ -57,18 +43,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": "${lookup(var.foo)}",
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&FunctionInterpolation{
+				"Call(lookup, Variable(var.foo))",
-					Func: nil,
-					Args: []Interpolation{
-						&VariableInterpolation{
-							Variable: &UserVariable{
-								Name: "foo",
-								key:  "var.foo",
-							},
-						},
-					},
-				},
 			},
 		},
 
@@ -76,15 +52,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": `${file("test.txt")}`,
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&FunctionInterpolation{
+				"Call(file, Literal(TypeString, test.txt))",
-					Func: nil,
-					Args: []Interpolation{
-						&LiteralInterpolation{
-							Literal: "test.txt",
-						},
-					},
-				},
 			},
 		},
 
@@ -92,15 +61,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": `${file("foo/bar.txt")}`,
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&FunctionInterpolation{
+				"Call(file, Literal(TypeString, foo/bar.txt))",
-					Func: nil,
-					Args: []Interpolation{
-						&LiteralInterpolation{
-							Literal: "foo/bar.txt",
-						},
-					},
-				},
 			},
 		},
 
@@ -108,25 +70,8 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": `${join(",", foo.bar.*.id)}`,
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&FunctionInterpolation{
+				"Call(join, Literal(TypeString, ,), Variable(foo.bar.*.id))",
-					Func: nil,
-					Args: []Interpolation{
-						&LiteralInterpolation{
-							Literal: ",",
-						},
-						&VariableInterpolation{
-							Variable: &ResourceVariable{
-								Type:  "foo",
-								Name:  "bar",
-								Field: "id",
-								Multi: true,
-								Index: -1,
-								key:   "foo.bar.*.id",
-							},
-						},
-					},
-				},
 			},
 		},
 
@@ -134,27 +79,16 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": `${concat("localhost", ":8080")}`,
 			},
-			Result: []Interpolation{
+			Result: []string{
-				&FunctionInterpolation{
+				"Call(concat, Literal(TypeString, localhost), Literal(TypeString, :8080))",
-					Func: nil,
-					Args: []Interpolation{
-						&LiteralInterpolation{
-							Literal: "localhost",
-						},
-						&LiteralInterpolation{
-							Literal: ":8080",
-						},
-					},
-				},
 			},
 		},
 	}
 
 	for i, tc := range cases {
-		var actual []Interpolation
+		var actual []string
-
+		detectFn := func(root ast.Node) (string, error) {
-		detectFn := func(i Interpolation) (string, error) {
+			actual = append(actual, fmt.Sprintf("%s", root))
-			actual = append(actual, i)
 			return "", nil
 		}
 
@@ -163,14 +97,6 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			t.Fatalf("err: %s", err)
 		}
 
-		for _, a := range actual {
-			// This is jank, but reflect.DeepEqual never has functions
-			// being the same.
-			if f, ok := a.(*FunctionInterpolation); ok {
-				f.Func = nil
-			}
-		}
-
 		if !reflect.DeepEqual(actual, tc.Result) {
 			t.Fatalf("%d: bad:\n\n%#v", i, actual)
 		}
@@ -198,7 +124,7 @@ func TestInterpolationWalker_replace(t *testing.T) {
 				"foo": "hello, ${var.foo}",
 			},
 			Output: map[string]interface{}{
-				"foo": "hello, bar",
+				"foo": "bar",
 			},
 			Value: "bar",
 		},
@@ -247,7 +173,7 @@ func TestInterpolationWalker_replace(t *testing.T) {
 	}
 
 	for i, tc := range cases {
-		fn := func(i Interpolation) (string, error) {
+		fn := func(ast.Node) (string, error) {
 			return tc.Value, nil
 		}
 

config/raw_config.go

@@ -4,6 +4,8 @@ import (
 	"bytes"
 	"encoding/gob"
 
+	"github.com/hashicorp/terraform/config/lang"
+	"github.com/hashicorp/terraform/config/lang/ast"
 	"github.com/mitchellh/copystructure"
 	"github.com/mitchellh/reflectwalk"
 )
@@ -26,7 +28,7 @@ const UnknownVariableValue = "74D93920-ED26-11E3-AC10-0800200C9A66"
 type RawConfig struct {
 	Key            string
 	Raw            map[string]interface{}
-	Interpolations []Interpolation
+	Interpolations []ast.Node
 	Variables      map[string]InterpolatedVariable
 
 	config      map[string]interface{}
@@ -79,8 +81,23 @@ func (r *RawConfig) Config() map[string]interface{} {
 //
 // If a variable key is missing, this will panic.
 func (r *RawConfig) Interpolate(vs map[string]string) error {
-	return r.interpolate(func(i Interpolation) (string, error) {
+	varMap := make(map[string]lang.Variable)
-		return i.Interpolate(vs)
+	for k, v := range vs {
+		varMap[k] = lang.Variable{Value: v, Type: ast.TypeString}
+	}
+	engine := &lang.Engine{
+		GlobalScope: &lang.Scope{
+			VarMap: varMap,
+		},
+	}
+
+	return r.interpolate(func(root ast.Node) (string, error) {
+		out, _, err := engine.Execute(root)
+		if err != nil {
+			return "", err
+		}
+
+		return out.(string), nil
 	})
 }
 
@@ -89,15 +106,19 @@ func (r *RawConfig) init() error {
 	r.Interpolations = nil
 	r.Variables = nil
 
-	fn := func(i Interpolation) (string, error) {
+	fn := func(node ast.Node) (string, error) {
-		r.Interpolations = append(r.Interpolations, i)
+		r.Interpolations = append(r.Interpolations, node)
+		vars, err := DetectVariables(node)
+		if err != nil {
+			return "", err
+		}
 
-		for k, v := range i.Variables() {
+		for _, v := range vars {
 			if r.Variables == nil {
 				r.Variables = make(map[string]InterpolatedVariable)
 			}
 
-			r.Variables[k] = v
+			r.Variables[v.FullKey()] = v
 		}
 
 		return "", nil