Add support for local reference targets (#150)

Author: radeksimko

decoder/expression_candidates.go

@@ -478,22 +478,23 @@ func (d *PathDecoder) candidatesForTraversalConstraint(tc schema.TraversalExpr,
 
 	prefix, _ := d.bytesFromRange(prefixRng)
 
-	d.pathCtx.ReferenceTargets.MatchWalk(tc, string(prefix), func(ref reference.Target) error {
+	d.pathCtx.ReferenceTargets.MatchWalk(tc, string(prefix), editRng, func(target reference.Target) error {
 		// avoid suggesting references to block's own fields from within (for now)
-		if ref.RangePtr != nil && outerBodyRng.Filename == ref.RangePtr.Filename &&
-			(outerBodyRng.ContainsPos(ref.RangePtr.Start) ||
-				posEqual(outerBodyRng.End, ref.RangePtr.End)) {
+		// TODO: Reflect LocalAddr here
+		if referenceTargetIsInRange(target, outerBodyRng) {
 			return nil
 		}
 
+		address := target.Address().String()
+
 		candidates = append(candidates, lang.Candidate{
-			Label:       ref.Addr.String(),
-			Detail:      ref.FriendlyName(),
-			Description: ref.Description,
+			Label:       address,
+			Detail:      target.FriendlyName(),
+			Description: target.Description,
 			Kind:        lang.TraversalCandidateKind,
 			TextEdit: lang.TextEdit{
-				NewText: ref.Addr.String(),
-				Snippet: ref.Addr.String(),
+				NewText: address,
+				Snippet: address,
 				Range:   editRng,
 			},
 		})
@@ -503,6 +504,13 @@ func (d *PathDecoder) candidatesForTraversalConstraint(tc schema.TraversalExpr,
 	return candidates
 }
 
+func referenceTargetIsInRange(target reference.Target, bodyRange hcl.Range) bool {
+	return target.RangePtr != nil &&
+		bodyRange.Filename == target.RangePtr.Filename &&
+		(bodyRange.ContainsPos(target.RangePtr.Start) ||
+			posEqual(bodyRange.End, target.RangePtr.End))
+}
+
 func newTextForConstraints(cons schema.ExprConstraints, isNested bool) string {
 	for _, constraint := range cons {
 		switch c := constraint.(type) {

decoder/hover.go

@@ -638,7 +638,7 @@ func (d *PathDecoder) hoverContentForTraversalExpr(traversal hcl.Traversal, tes
 		return "", nil
 	}
 
-	targets, ok := d.pathCtx.ReferenceTargets.Match(origin.Address(), origin.OriginConstraints())
+	targets, ok := d.pathCtx.ReferenceTargets.Match(origin)
 	if !ok {
 		return "", &reference.NoTargetFound{}
 	}
@@ -648,7 +648,7 @@ func (d *PathDecoder) hoverContentForTraversalExpr(traversal hcl.Traversal, tes
 }
 
 func hoverContentForReferenceTarget(ref reference.Target) (string, error) {
-	content := fmt.Sprintf("`%s`", ref.Addr.String())
+	content := fmt.Sprintf("`%s`", ref.Address())
 
 	var friendlyName string
 	if ref.Type != cty.NilType {

decoder/reference_targets.go

@@ -55,7 +55,7 @@ func (d *Decoder) ReferenceTargetsForOriginAtPos(path lang.Path, file string, po
 		if !ok {
 			continue
 		}
-		targets, ok := targetCtx.ReferenceTargets.Match(matchableOrigin.Address(), matchableOrigin.OriginConstraints())
+		targets, ok := targetCtx.ReferenceTargets.Match(matchableOrigin)
 		if !ok {
 			// target not found
 			continue

decoder/semantic_tokens.go

@@ -207,7 +207,7 @@ func (d *PathDecoder) tokensForExpression(ctx context.Context, expr hclsyntax.Ex
 				return tokens
 			}
 
-			_, targetFound := d.pathCtx.ReferenceTargets.Match(origin.Address(), origin.OriginConstraints())
+			_, targetFound := d.pathCtx.ReferenceTargets.Match(origin)
 			if !targetFound {
 				return tokens
 			}

lang/address.go

@@ -9,6 +9,13 @@ import (
 type Address []AddressStep
 
 func (a Address) Equals(addr Address) bool {
+	// Empty address may come up in context where there are
+	// two addresses for the same target and only is declared
+	// (LocalAddr / Addr) in which case we don't want the empty
+	// one to be treated as a match.
+	if len(a) == 0 && len(addr) == 0 {
+		return false
+	}
 	if len(a) != len(addr) {
 		return false
 	}

reference/origins.go

@@ -37,11 +37,11 @@ func (ro Origins) Match(localPath lang.Path, target Target, targetPath lang.Path
 	for _, refOrigin := range ro {
 		switch origin := refOrigin.(type) {
 		case LocalOrigin:
-			if localPath.Equals(targetPath) && target.Matches(origin.Address(), origin.OriginConstraints()) {
+			if localPath.Equals(targetPath) && target.Matches(origin) {
 				origins = append(origins, refOrigin)
 			}
 		case PathOrigin:
-			if origin.TargetPath.Equals(targetPath) && target.Matches(origin.Address(), origin.OriginConstraints()) {
+			if origin.TargetPath.Equals(targetPath) && target.Matches(origin) {
 				origins = append(origins, refOrigin)
 			}
 		}

reference/target.go

@@ -8,7 +8,28 @@ import (
 )
 
 type Target struct {
-	Addr    lang.Address
+	// Addr represents the address of the target, as available
+	// elsewhere in the configuration
+	Addr lang.Address
+
+	// LocalAddr represents the address of the target
+	// as available *locally* (e.g. self.attr_name)
+	LocalAddr lang.Address
+
+	// TargetableFromRangePtr defines where the target is targetable from.
+	// This is considered when matching the target against origin.
+	//
+	// e.g. count.index is only available within the body of the block
+	// where count is declared (and extension enabled)
+	TargetableFromRangePtr *hcl.Range
+
+	// ScopeId provides scope for matching/filtering
+	// (in addition to Type & Addr/LocalAddr).
+	//
+	// There should never be two targets with the same Type & address,
+	// but there are contexts (e.g. completion) where we don't filter
+	// by address and may not have type either (e.g. because targets
+	// are type-unaware).
 	ScopeId lang.ScopeId
 
 	// RangePtr represents range of the whole attribute or block
@@ -31,16 +52,38 @@ type Target struct {
 	NestedTargets Targets
 }
 
+// rangeOverlaps is a copy of hcl.Range.Overlaps
+// https://github.com/hashicorp/hcl/blob/v2.14.1/pos.go#L195-L212
+// which accounts for empty ranges that are common in the context of LS
+func rangeOverlaps(one, other hcl.Range) bool {
+	switch {
+	case one.Filename != other.Filename:
+		// If the ranges are in different files then they can't possibly overlap
+		return false
+	case one.Empty() && other.Empty():
+		// Empty ranges can never overlap
+		return false
+	case one.ContainsOffset(other.Start.Byte) || one.ContainsOffset(other.End.Byte):
+		return true
+	case other.ContainsOffset(one.Start.Byte) || other.ContainsOffset(one.End.Byte):
+		return true
+	default:
+		return false
+	}
+}
+
 func (ref Target) Copy() Target {
 	return Target{
-		Addr:          ref.Addr,
-		ScopeId:       ref.ScopeId,
-		RangePtr:      copyHclRangePtr(ref.RangePtr),
-		DefRangePtr:   copyHclRangePtr(ref.DefRangePtr),
-		Type:          ref.Type, // cty.Type is immutable by design
-		Name:          ref.Name,
-		Description:   ref.Description,
-		NestedTargets: ref.NestedTargets.Copy(),
+		Addr:                   ref.Addr,
+		LocalAddr:              ref.LocalAddr,
+		TargetableFromRangePtr: copyHclRangePtr(ref.TargetableFromRangePtr),
+		ScopeId:                ref.ScopeId,
+		RangePtr:               copyHclRangePtr(ref.RangePtr),
+		DefRangePtr:            copyHclRangePtr(ref.DefRangePtr),
+		Type:                   ref.Type, // cty.Type is immutable by design
+		Name:                   ref.Name,
+		Description:            ref.Description,
+		NestedTargets:          ref.NestedTargets.Copy(),
 	}
 }
 
@@ -51,8 +94,16 @@ func copyHclRangePtr(rng *hcl.Range) *hcl.Range {
 	return rng.Ptr()
 }
 
+// Address returns any of the two non-empty addresses
+//
+// TODO: Return address based on context when we have both
 func (r Target) Address() lang.Address {
-	return r.Addr
+	addr := r.Addr
+	if len(r.LocalAddr) > 0 {
+		addr = r.LocalAddr
+	}
+
+	return addr
 }
 
 func (r Target) FriendlyName() string {
@@ -98,26 +149,32 @@ func (ref Target) ConformsToType(typ cty.Type) bool {
 	return conformsToType || (typ == cty.NilType && ref.Type == cty.NilType)
 }
 
-func (target Target) Matches(addr lang.Address, cons OriginConstraints) bool {
-	if len(target.Addr) > len(addr) {
+func (target Target) Matches(origin MatchableOrigin) bool {
+	if len(target.LocalAddr) > len(origin.Address()) && len(target.Addr) > len(origin.Address()) {
 		return false
 	}
 
-	originAddr := addr
+	originAddr, localOriginAddr := origin.Address(), origin.Address()
 
 	matchesCons := false
 
-	if len(cons) == 0 && target.Type != cty.NilType {
-		matchesCons = true
+	// Unconstrained origins should be uncommon, but they match any target
+	if len(origin.OriginConstraints()) == 0 {
+		// As long as the target is type-aware. Type-unaware targets
+		// generally don't have Type, so we avoid false positive here.
+		if target.Type != cty.NilType {
+			matchesCons = true
+		}
 	}
 
-	for _, cons := range cons {
+	for _, cons := range origin.OriginConstraints() {
 		if !target.MatchesScopeId(cons.OfScopeId) {
 			continue
 		}
 
 		if target.Type == cty.DynamicPseudoType {
-			originAddr = addr.FirstSteps(uint(len(target.Addr)))
+			originAddr = origin.Address().FirstSteps(uint(len(target.Addr)))
+			localOriginAddr = origin.Address().FirstSteps(uint(len(target.LocalAddr)))
 			matchesCons = true
 			continue
 		}
@@ -130,5 +187,10 @@ func (target Target) Matches(addr lang.Address, cons OriginConstraints) bool {
 		}
 	}
 
-	return target.Addr.Equals(originAddr) && matchesCons
+	// Reject origin if it's outside the targetable range
+	if target.TargetableFromRangePtr != nil && !rangeOverlaps(*target.TargetableFromRangePtr, origin.OriginRange()) {
+		return false
+	}
+
+	return (target.LocalAddr.Equals(localOriginAddr) || target.Addr.Equals(originAddr)) && matchesCons
 }

reference/targets.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"strings"
 
-	"github.com/hashicorp/hcl-lang/lang"
 	"github.com/hashicorp/hcl-lang/schema"
 	"github.com/hashicorp/hcl/v2"
 )
@@ -29,7 +28,8 @@ func (r Targets) Len() int {
 }
 
 func (r Targets) Less(i, j int) bool {
-	return r[i].Addr.String() < r[j].Addr.String()
+	return r[i].LocalAddr.String() < r[j].LocalAddr.String() ||
+		r[i].Addr.String() < r[j].Addr.String()
 }
 
 func (r Targets) Swap(i, j int) {
@@ -72,23 +72,36 @@ func (w refTargetDeepWalker) walk(refTargets Targets) {
 	}
 }
 
-func (refs Targets) MatchWalk(te schema.TraversalExpr, prefix string, f TargetWalkFunc) {
+func (refs Targets) MatchWalk(te schema.TraversalExpr, prefix string, originRng hcl.Range, f TargetWalkFunc) {
 	for _, ref := range refs {
-		if strings.HasPrefix(ref.Addr.String(), string(prefix)) {
+		if len(ref.LocalAddr) > 0 && strings.HasPrefix(ref.LocalAddr.String(), prefix) {
+			// Check if origin is inside the targetable range
+			if ref.TargetableFromRangePtr == nil || rangeOverlaps(*ref.TargetableFromRangePtr, originRng) {
+				nestedMatches := ref.NestedTargets.containsMatch(te, prefix)
+				if ref.MatchesConstraint(te) || nestedMatches {
+					f(ref)
+				}
+			}
+		}
+		if len(ref.Addr) > 0 && strings.HasPrefix(ref.Addr.String(), prefix) {
 			nestedMatches := ref.NestedTargets.containsMatch(te, prefix)
 			if ref.MatchesConstraint(te) || nestedMatches {
 				f(ref)
 				continue
 			}
 		}
 
-		ref.NestedTargets.MatchWalk(te, prefix, f)
+		ref.NestedTargets.MatchWalk(te, prefix, originRng, f)
 	}
 }
 
 func (refs Targets) containsMatch(te schema.TraversalExpr, prefix string) bool {
 	for _, ref := range refs {
-		if strings.HasPrefix(ref.Addr.String(), string(prefix)) &&
+		if strings.HasPrefix(ref.LocalAddr.String(), prefix) &&
+			ref.MatchesConstraint(te) {
+			return true
+		}
+		if strings.HasPrefix(ref.Addr.String(), prefix) &&
 			ref.MatchesConstraint(te) {
 			return true
 		}
@@ -101,13 +114,14 @@ func (refs Targets) containsMatch(te schema.TraversalExpr, prefix string) bool {
 	return false
 }
 
-func (refs Targets) Match(addr lang.Address, cons OriginConstraints) (Targets, bool) {
+func (refs Targets) Match(origin MatchableOrigin) (Targets, bool) {
 	matchingReferences := make(Targets, 0)
 
 	refs.deepWalk(func(ref Target) error {
-		if ref.Matches(addr, cons) {
+		if ref.Matches(origin) {
 			matchingReferences = append(matchingReferences, ref)
 		}
+
 		return nil
 	}, InfiniteDepth)