diff options
author | Vincent Ambo <mail@tazj.in> | 2022-09-01T22·19+0300 |
---|---|---|
committer | tazjin <tazjin@tvl.su> | 2022-09-08T07·59+0000 |
commit | 5ee89bcf5ca3f0b0d3b809b01ac04bf38f51d7e4 (patch) | |
tree | 1e8f3481d968b41020a2bb0fc32447dfd3e5ff7e | |
parent | 0a13d267f0aa0ab1c70b6ac0e0ee8a44071b3d40 (diff) |
fix(tvix/eval): inherit scope poisoning data in nested contexts r/4743
Scope poisoning must be inherited across lambda context boundaries, e.g. if an outer scope has a poisoned `null`, any lambdas defined on the same level must reference that poisoned identifier correctly. Change-Id: I1aac64e1c048a6f3bacadb6d78ed295fa439e8b4 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6410 Reviewed-by: sterni <sternenseemann@systemli.org> Tested-by: BuildkiteCI
Diffstat (limited to '')
-rw-r--r-- | tvix/eval/src/compiler/mod.rs | 26 | ||||
-rw-r--r-- | tvix/eval/src/compiler/scope.rs | 9 | ||||
-rw-r--r-- | tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.exp | 1 | ||||
-rw-r--r-- | tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.nix | 4 |
4 files changed, 36 insertions, 4 deletions
diff --git a/tvix/eval/src/compiler/mod.rs b/tvix/eval/src/compiler/mod.rs index cc98c2e852f2..2d499564077d 100644 --- a/tvix/eval/src/compiler/mod.rs +++ b/tvix/eval/src/compiler/mod.rs @@ -53,6 +53,13 @@ impl LambdaCtx { scope: Default::default(), } } + + fn inherit(&self) -> Self { + LambdaCtx { + lambda: Lambda::new_anonymous(), + scope: self.scope.inherit(), + } + } } /// Alias for the map of globally available functions that should @@ -836,9 +843,7 @@ impl Compiler<'_> { } fn compile_lambda(&mut self, slot: Option<LocalIdx>, node: ast::Lambda) { - // Open new lambda context in compiler, which has its own - // scope etc. - self.contexts.push(LambdaCtx::new()); + self.new_context(); self.begin_scope(); // Compile the function itself @@ -912,7 +917,7 @@ impl Compiler<'_> { N: AstNode + Clone, F: FnOnce(&mut Compiler, &N, Option<LocalIdx>), { - self.contexts.push(LambdaCtx::new()); + self.new_context(); self.begin_scope(); content(self, node, slot); self.end_scope(node); @@ -1011,10 +1016,14 @@ impl Compiler<'_> { } } + /// Increase the scope depth of the current function (e.g. within + /// a new bindings block, or `with`-scope). fn begin_scope(&mut self) { self.scope_mut().scope_depth += 1; } + /// Decrease scope depth of the current function and emit + /// instructions to clean up the stack at runtime. fn end_scope<N: AstNode>(&mut self, node: &N) { debug_assert!(self.scope().scope_depth != 0, "can not end top scope"); @@ -1055,6 +1064,15 @@ impl Compiler<'_> { } } + /// Open a new lambda context within which to compile a function, + /// closure or thunk. + fn new_context(&mut self) { + // This must inherit the scope-poisoning status of the parent + // in order for upvalue resolution to work correctly with + // poisoned identifiers. + self.contexts.push(self.context().inherit()); + } + /// Declare a local variable known in the scope that is being /// compiled by pushing it to the locals. This is used to /// determine the stack offset of variables. diff --git a/tvix/eval/src/compiler/scope.rs b/tvix/eval/src/compiler/scope.rs index b1ad4bfcd2b7..a50b3b79343e 100644 --- a/tvix/eval/src/compiler/scope.rs +++ b/tvix/eval/src/compiler/scope.rs @@ -152,6 +152,15 @@ impl Scope { } } + /// Inherit scope details from a parent scope (required for + /// correctly nesting scopes in lambdas and thunks when special + /// scope features like poisoning are present). + pub fn inherit(&self) -> Self { + let mut scope = Self::default(); + scope.poisoned_tokens = self.poisoned_tokens.clone(); + scope + } + /// Check whether a given token is poisoned. pub fn is_poisoned(&self, name: &str) -> bool { self.poisoned_tokens.contains_key(name) diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.exp b/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.exp new file mode 100644 index 000000000000..d81cc0710eb6 --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.exp @@ -0,0 +1 @@ +42 diff --git a/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.nix b/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.nix new file mode 100644 index 000000000000..8d0280bb8973 --- /dev/null +++ b/tvix/eval/src/tests/tvix_tests/eval-okay-nested-poisoning.nix @@ -0,0 +1,4 @@ +let + null = 1; + f = n: n + null; +in f 41 |