Function normalizeIDs

cel/optimizer.go:134–176

normalizeIDs ensures that the metadata present with an AST is reset in a manner such that the ids within the expression correspond to the ids within macros.

(idGen ast.IDGenerator, optimized ast.Expr, info *ast.SourceInfo)

// normalizeIDs ensures that the metadata present with an AST is reset in a manner such
// that the ids within the expression correspond to the ids within macros.
func normalizeIDs(idGen ast.IDGenerator, optimized ast.Expr, info *ast.SourceInfo) {
	optimized.RenumberIDs(idGen)
	info.RenumberIDs(idGen)

	if len(info.MacroCalls()) == 0 {
		return
	}

	// Sort the macro ids to make sure that the renumbering of macro-specific variables
	// is stable across normalization calls.
	sortedMacroIDs := []int64{}
	for id := range info.MacroCalls() {
		sortedMacroIDs = append(sortedMacroIDs, id)
	}
	sort.Slice(sortedMacroIDs, func(i, j int) bool { return sortedMacroIDs[i] < sortedMacroIDs[j] })

	// First, update the macro call ids themselves.
	callIDMap := map[int64]int64{}
	for _, id := range sortedMacroIDs {
		callIDMap[id] = idGen(id)
	}
	// Then update the macro call definitions which refer to these ids, but
	// ensure that the updates don't collide and remove macro entries which haven't
	// been visited / updated yet.
	type macroUpdate struct {
		id   int64
		call ast.Expr
	}
	macroUpdates := []macroUpdate{}
	for _, oldID := range sortedMacroIDs {
		newID := callIDMap[oldID]
		call, found := info.GetMacroCall(oldID)
		if !found {
			continue
		}
		call.RenumberIDs(idGen)
		macroUpdates = append(macroUpdates, macroUpdate{id: newID, call: call})
		info.ClearMacroCall(oldID)
	}
	for _, u := range macroUpdates {
		info.SetMacroCall(u.id, u.call)
	}
}

func cleanupMacroRefs(expr ast.Expr, info *ast.SourceInfo) {
	if len(info.MacroCalls()) == 0 {