fix(tvix/eval): correctly account for slots during list construction r/4798

Similarly to attribute sets, list elements can be arbitrary
expressions and their (temporary) stack slots during construction must
be accounted for by the compiler.

Change-Id: I3b6f7927860627fd867c64d0cab9104fd636d4f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6470
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

2 files changed, 14 insertions, 0 deletions

diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.exp b/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.exp
new file mode 100644
index 000000000000..5776134d0e41
--- /dev/null
+++ b/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.exp
@@ -0,0 +1 @@
+[ 1 2 3 ]
diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.nix b/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.nix
new file mode 100644
index 000000000000..bb62fdf31cd7
--- /dev/null
+++ b/tvix/eval/src/tests/tvix_tests/eval-okay-with-in-list.nix
@@ -0,0 +1,13 @@
+# This code causes a situation where a list element causes an
+# additional phantom value to temporarily be placed on the locals
+# stack, which must be correctly accounted for by the compiler.
+
+let
+  set = {
+    value = 2;
+  };
+in [
+  1
+  (with set; value)
+  3
+]