expression: cache the cacheability property

1 files changed, 6 insertions, 1 deletions

diff --git a/src/buildtool/build_engine/expression/expression.cpp b/src/buildtool/build_engine/expression/expression.cpp
index 6ae9bd87..6891d7ab 100644
--- a/src/buildtool/build_engine/expression/expression.cpp
+++ b/src/buildtool/build_engine/expression/expression.cpp
@@ -114,7 +114,7 @@ auto Expression::ToJson(Expression::JsonMode mode) const -> nlohmann::json {
 }
 
 // NOLINTNEXTLINE(misc-no-recursion)
-auto Expression::IsCacheable() const -> bool {
+auto Expression::ComputeIsCacheable() const -> bool {
     // Must be updated whenever we add a new non-cacheable value
     if (IsName()) {
         return false;
@@ -153,6 +153,11 @@ auto Expression::ToHash() const noexcept -> std::string {
 }
 
 // NOLINTNEXTLINE(misc-no-recursion)
+auto Expression::IsCacheable() const -> bool {
+    return is_cachable_.SetOnceAndGet([this] { return ComputeIsCacheable(); });
+}
+
+// NOLINTNEXTLINE(misc-no-recursion)
 auto Expression::FromJson(nlohmann::json const& json) noexcept
     -> ExpressionPtr {
     if (json.is_null()) {