Skip to content

expr: fix eager evaluation of parenthesized dead branches #11395

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
can1357 wants to merge 1 commit into
base: main
Choose a base branch
from
Open

expr: fix eager evaluation of parenthesized dead branches #11395

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 2 additions & 21 deletions src/uu/expr/src/syntax_tree.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -624,9 +624,6 @@ pub struct AstNode {
#[derive(Debug, Clone)]
#[cfg_attr(test, derive(Eq, PartialEq))]
pub enum AstNodeInner {
Evaluated {
value: NumOrStr,
},
Leaf {
value: MaybeNonUtf8String,
},
Expand All @@ -650,15 +647,6 @@ impl AstNode {
Parser::new(input).parse()
}

pub fn evaluated(self) -> ExprResult<Self> {
Ok(Self {
id: get_next_id(),
inner: AstNodeInner::Evaluated {
value: self.eval()?,
},
})
}

pub fn eval(&self) -> ExprResult<NumOrStr> {
// This function implements a recursive tree-walking algorithm, but uses an explicit
// stack approach instead of native recursion to avoid potential stack overflow
Expand All @@ -669,9 +657,6 @@ impl AstNode {

while let Some(node) = stack.pop() {
match &node.inner {
AstNodeInner::Evaluated { value, .. } => {
result_stack.insert(node.id, Ok(value.clone()));
}
AstNodeInner::Leaf { value, .. } => {
result_stack.insert(node.id, Ok(value.to_owned().into()));
}
Expand Down Expand Up @@ -896,9 +881,7 @@ impl<'a, S: AsRef<MaybeNonUtf8Str>> Parser<'a, S> {
value: self.next()?.into(),
},
b"(" => {
// Evaluate the node just after parsing to we detect arithmetic
// errors before checking for the closing parenthesis.
let s = self.parse_expression()?.evaluated()?;
let s = self.parse_expression()?;

match self.next() {
Ok(b")") => {}
Expand Down Expand Up @@ -1070,9 +1053,7 @@ mod test {
AstNode::parse(&["(", "1", "+", "2", ")", "*", "3"]),
Ok(op(
BinOp::Numeric(NumericOp::Mul),
op(BinOp::Numeric(NumericOp::Add), "1", "2")
.evaluated()
.unwrap(),
op(BinOp::Numeric(NumericOp::Add), "1", "2"),
"3"
))
);
Expand Down
27 changes: 25 additions & 2 deletions tests/by-util/test_expr.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,29 @@ fn test_and() {
new_ucmd!().args(&["", "&", ""]).fails().stdout_only("0\n");
}

#[test]
fn test_parenthesized_short_circuit_dead_branches() {
new_ucmd!()
.args(&["1", "|", "(", "1", "/", "0", ")"])
.succeeds()
.stdout_only("1\n");

new_ucmd!()
.args(&["0", "&", "(", "1", "/", "0", ")"])
.fails_with_code(1)
.stdout_only("0\n");

new_ucmd!()
.args(&["1", "|", "(", "0", "&", "(", "1", "/", "0", ")", ")"])
.succeeds()
.stdout_only("1\n");

new_ucmd!()
.args(&["0", "&", "(", "1", "|", "(", "1", "/", "0", ")", ")"])
.fails_with_code(1)
.stdout_only("0\n");
}

#[test]
fn test_length_fail() {
new_ucmd!().args(&["length", "αbcdef", "1"]).fails();
Expand Down Expand Up @@ -580,11 +603,11 @@ fn test_num_str_comparison() {
}

#[test]
fn test_eager_evaluation() {
fn test_missing_closing_parenthesis_reports_syntax_error() {
new_ucmd!()
.args(&["(", "1", "/", "0"])
.fails()
.stderr_contains("division by zero");
.stderr_contains("expecting ')' after '0'");
}

#[test]
Expand Down
Loading