From cd744f0aa705882f0e4fd0466e24cdbccf9fc28f Mon Sep 17 00:00:00 2001
From: René Kijewski <kijewski@library.vetmed.fu-berlin.de>
Date: Mon, 31 Jan 2022 08:38:44 +0100
Subject: Make is_shadowing_variable() failable
---
askama_shared/src/generator.rs | 36 ++++++++++++++++++---------
testing/tests/ui/lit_on_assignment_lhs.stderr | 6 ++---
2 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/askama_shared/src/generator.rs b/askama_shared/src/generator.rs
index 7080b87..acd716b 100644
--- a/askama_shared/src/generator.rs
+++ b/askama_shared/src/generator.rs
@@ -804,26 +804,38 @@ impl<'a, S: std::hash::BuildHasher> Generator<'a, S> {
buf.writeln(";")
}
- fn is_shadowing_variable(&self, var: &Target<'a>) -> bool {
+ fn is_shadowing_variable(&self, var: &Target<'a>) -> Result<bool, CompileError> {
match var {
Target::Name(name) => {
let name = normalize_identifier(name);
match self.locals.get(&name) {
// declares a new variable
- None => false,
+ None => Ok(false),
// an initialized variable gets shadowed
- Some(meta) if meta.initialized => true,
+ Some(meta) if meta.initialized => Ok(true),
// initializes a variable that was introduced in a LetDecl before
- _ => false,
+ _ => Ok(false),
}
}
- Target::Tuple(_, targets) => targets
- .iter()
- .any(|target| self.is_shadowing_variable(target)),
- Target::Struct(_, named_targets) => named_targets
- .iter()
- .any(|(_, target)| self.is_shadowing_variable(target)),
- _ => panic!("Cannot have literals on the left-hand-side of an assignment."),
+ Target::Tuple(_, targets) => {
+ for target in targets {
+ match self.is_shadowing_variable(target) {
+ Ok(false) => continue,
+ outcome => return outcome,
+ }
+ }
+ Ok(false)
+ }
+ Target::Struct(_, named_targets) => {
+ for (_, target) in named_targets {
+ match self.is_shadowing_variable(target) {
+ Ok(false) => continue,
+ outcome => return outcome,
+ }
+ }
+ Ok(false)
+ }
+ _ => Err("literals are not allowed on the left-hand side of an assignment".into()),
}
}
@@ -838,7 +850,7 @@ impl<'a, S: std::hash::BuildHasher> Generator<'a, S> {
let mut expr_buf = Buffer::new(0);
self.visit_expr(&mut expr_buf, val)?;
- let shadowed = self.is_shadowing_variable(var);
+ let shadowed = self.is_shadowing_variable(var)?;
if shadowed {
// Need to flush the buffer if the variable is being shadowed,
// to ensure the old variable is used.
diff --git a/testing/tests/ui/lit_on_assignment_lhs.stderr b/testing/tests/ui/lit_on_assignment_lhs.stderr
index fa488cb..53bfc81 100644
--- a/testing/tests/ui/lit_on_assignment_lhs.stderr
+++ b/testing/tests/ui/lit_on_assignment_lhs.stderr
@@ -1,7 +1,7 @@
-error: proc-macro derive panicked
- --> $DIR/lit_on_assignment_lhs.rs:3:10
+error: literals are not allowed on the left-hand side of an assignment
+ --> tests/ui/lit_on_assignment_lhs.rs:3:10
|
3 | #[derive(Template)]
| ^^^^^^^^
|
- = help: message: Cannot have literals on the left-hand-side of an assignment.
+ = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)
--
cgit