Implement limits for parsing depth in the new parser. (#3762)

core/src/syn/v2/parser/error.rs

@@ -74,6 +74,8 @@ pub enum ParseErrorKind {
 		idiom: String,
 		kind: MissingKind,
 	},
+	ExceededObjectDepthLimit,
+	ExceededQueryDepthLimit,
 	NoWhitespace,
 }
 
@@ -246,6 +248,24 @@ impl ParseError {
 					snippets: vec![snippet],
 				}
 			}
+			ParseErrorKind::ExceededObjectDepthLimit => {
+				let text = "Parsing exceeded the depth limit for objects";
+				let locations = Location::range_of_span(source, at);
+				let snippet = Snippet::from_source_location_range(source, locations, None);
+				RenderedError {
+					text: text.to_string(),
+					snippets: vec![snippet],
+				}
+			}
+			ParseErrorKind::ExceededQueryDepthLimit => {
+				let text = "Parsing exceeded the depth limit for queries";
+				let locations = Location::range_of_span(source, at);
+				let snippet = Snippet::from_source_location_range(source, locations, None);
+				RenderedError {
+					text: text.to_string(),
+					snippets: vec![snippet],
+				}
+			}
 			ParseErrorKind::MissingField {
 				field,
 				idiom,

core/src/syn/v2/parser/mac.rs

@@ -74,6 +74,83 @@ macro_rules! test_parse {
 	}};
 }
 
+#[macro_export]
+macro_rules! enter_object_recursion {
+	($name:ident = $this:expr => { $($t:tt)* }) => {{
+		if $this.object_recursion == 0 {
+			return Err($crate::syn::v2::parser::ParseError::new(
+				$crate::syn::v2::parser::ParseErrorKind::ExceededObjectDepthLimit,
+				$this.last_span(),
+			));
+		}
+		struct Dropper<'a, 'b>(&'a mut $crate::syn::v2::parser::Parser<'b>);
+		impl Drop for Dropper<'_, '_> {
+			fn drop(&mut self) {
+				self.0.object_recursion += 1;
+			}
+		}
+		impl<'a> ::std::ops::Deref for Dropper<'_,'a>{
+			type Target = $crate::syn::v2::parser::Parser<'a>;
+
+			fn deref(&self) -> &Self::Target{
+				self.0
+			}
+		}
+
+		impl<'a> ::std::ops::DerefMut for Dropper<'_,'a>{
+			fn deref_mut(&mut self) -> &mut Self::Target{
+				self.0
+			}
+		}
+
+		$this.object_recursion -= 1;
+		let mut $name = Dropper($this);
+		{
+			$($t)*
+		}
+	}};
+}
+
+#[macro_export]
+macro_rules! enter_query_recursion {
+	($name:ident = $this:expr => { $($t:tt)* }) => {{
+
+        println!("{} = {}",$this.query_recursion, std::backtrace::Backtrace::force_capture());
+		if $this.query_recursion == 0 {
+			return Err($crate::syn::v2::parser::ParseError::new(
+				$crate::syn::v2::parser::ParseErrorKind::ExceededQueryDepthLimit,
+				$this.last_span(),
+			));
+		}
+		struct Dropper<'a, 'b>(&'a mut $crate::syn::v2::parser::Parser<'b>);
+		impl Drop for Dropper<'_, '_> {
+			fn drop(&mut self) {
+				self.0.query_recursion += 1;
+			}
+		}
+		impl<'a> ::std::ops::Deref for Dropper<'_,'a>{
+			type Target = $crate::syn::v2::parser::Parser<'a>;
+
+			fn deref(&self) -> &Self::Target{
+				self.0
+			}
+		}
+
+		impl<'a> ::std::ops::DerefMut for Dropper<'_,'a>{
+			fn deref_mut(&mut self) -> &mut Self::Target{
+				self.0
+			}
+		}
+
+		$this.query_recursion -= 1;
+        #[allow(unused_mut)]
+		let mut $name = Dropper($this);
+		{
+			$($t)*
+		}
+	}};
+}
+
 pub(super) use expected;
 pub(super) use unexpected;
 

core/src/syn/v2/parser/mod.rs

@@ -24,6 +24,7 @@ use crate::{
 		token::{t, Span, Token, TokenKind},
 	},
 };
+use reblessive::Stk;
 
 mod basic;
 mod builtin;
@@ -44,7 +45,6 @@ mod token_buffer;
 pub mod test;
 
 pub use error::{IntErrorKind, ParseError, ParseErrorKind};
-use reblessive::Stk;
 
 /// The result returned by most parser function.
 pub type ParseResult<T> = Result<T, ParseError>;

core/src/syn/v2/parser/object.rs

@@ -4,6 +4,7 @@ use geo_types::{LineString, MultiLineString, MultiPoint, MultiPolygon, Point, Po
 use reblessive::Stk;
 
 use crate::{
+	enter_object_recursion,
 	sql::{Block, Geometry, Object, Strand, Value},
 	syn::v2::{
 		parser::{mac::expected, ParseError, ParseErrorKind, ParseResult, Parser},
@@ -24,12 +25,16 @@ impl Parser<'_> {
 	) -> ParseResult<Value> {
 		if self.eat(t!("}")) {
 			// empty object, just return
-			return Ok(Value::Object(Object::default()));
+			enter_object_recursion!(_this = self => {
+				return Ok(Value::Object(Object::default()));
+			})
 		}
 
 		// Check first if it can be an object.
 		if self.peek_token_at(1).kind == t!(":") {
-			return self.parse_object_or_geometry(ctx, start).await;
+			enter_object_recursion!(this = self => {
+			   return this.parse_object_or_geometry(ctx, start).await;
+			})
 		}
 
 		// not an object so instead parse as a block.
@@ -582,7 +587,9 @@ impl Parser<'_> {
 	/// # Parser state
 	/// Expects the first `{` to already have been eaten.
 	pub(super) async fn parse_object(&mut self, ctx: &mut Stk, start: Span) -> ParseResult<Object> {
-		self.parse_object_from_map(ctx, BTreeMap::new(), start).await
+		enter_object_recursion!(this = self => {
+			this.parse_object_from_map(ctx, BTreeMap::new(), start).await
+		})
 	}
 
 	async fn parse_object_from_map(

core/src/syn/v2/parser/prime.rs

@@ -3,6 +3,7 @@ use reblessive::Stk;
 
 use super::{ParseResult, Parser};
 use crate::{
+	enter_query_recursion,
 	sql::{
 		Array, Dir, Function, Geometry, Ident, Idiom, Mock, Part, Script, Strand, Subquery, Table,
 		Value,
@@ -221,9 +222,11 @@ impl Parser<'_> {
 				self.parse_mock(token.span).map(Value::Mock)?
 			}
 			t!("IF") => {
-				self.pop_peek();
-				let stmt = ctx.run(|ctx| self.parse_if_stmt(ctx)).await?;
-				Value::Subquery(Box::new(Subquery::Ifelse(stmt)))
+				enter_query_recursion!(this = self => {
+					this.pop_peek();
+					let stmt = ctx.run(|ctx| this.parse_if_stmt(ctx)).await?;
+					Value::Subquery(Box::new(Subquery::Ifelse(stmt)))
+				})
 			}
 			t!("(") => {
 				self.pop_peek();
@@ -341,9 +344,11 @@ impl Parser<'_> {
 				self.parse_inner_subquery(ctx, Some(peek.span)).await
 			}
 			t!("IF") => {
-				self.pop_peek();
-				let if_stmt = ctx.run(|ctx| self.parse_if_stmt(ctx)).await?;
-				Ok(Subquery::Ifelse(if_stmt))
+				enter_query_recursion!(this = self => {
+					this.pop_peek();
+					let if_stmt = ctx.run(|ctx| this.parse_if_stmt(ctx)).await?;
+					Ok(Subquery::Ifelse(if_stmt))
+				})
 			}
 			_ => self.parse_inner_subquery(ctx, None).await,
 		}
@@ -353,6 +358,16 @@ impl Parser<'_> {
 		&mut self,
 		ctx: &mut Stk,
 		start: Span,
+	) -> ParseResult<Value> {
+		enter_query_recursion!(this = self => {
+			this.parse_inner_subquery_or_coordinate_inner(ctx,start).await
+		})
+	}
+
+	async fn parse_inner_subquery_or_coordinate_inner(
+		&mut self,
+		ctx: &mut Stk,
+		start: Span,
 	) -> ParseResult<Value> {
 		let peek = self.peek();
 		let res = match peek.kind {
@@ -489,6 +504,16 @@ impl Parser<'_> {
 		&mut self,
 		ctx: &mut Stk,
 		start: Option<Span>,
+	) -> ParseResult<Subquery> {
+		enter_query_recursion!(this = self => {
+			this.parse_inner_subquery_inner(ctx,start).await
+		})
+	}
+
+	async fn parse_inner_subquery_inner(
+		&mut self,
+		ctx: &mut Stk,
+		start: Option<Span>,
 	) -> ParseResult<Subquery> {
 		let peek = self.peek();
 		let res = match peek.kind {

core/src/syn/v2/parser/stmt/mod.rs

@@ -1,5 +1,6 @@
 use reblessive::Stk;
 
+use crate::enter_query_recursion;
 use crate::sql::block::Entry;
 use crate::sql::statements::show::{ShowSince, ShowStatement};
 use crate::sql::statements::sleep::SleepStatement;
@@ -92,6 +93,12 @@ impl Parser<'_> {
 	}
 
 	pub(super) async fn parse_stmt(&mut self, ctx: &mut Stk) -> ParseResult<Statement> {
+		enter_query_recursion!(this = self => {
+			this.parse_stmt_inner(ctx).await
+		})
+	}
+
+	async fn parse_stmt_inner(&mut self, ctx: &mut Stk) -> ParseResult<Statement> {
 		let token = self.peek();
 		match token.kind {
 			t!("ANALYZE") => {
@@ -207,6 +214,12 @@ impl Parser<'_> {
 	}
 
 	pub(super) async fn parse_entry(&mut self, ctx: &mut Stk) -> ParseResult<Entry> {
+		enter_query_recursion!(this = self => {
+			this.parse_entry_inner(ctx).await
+		})
+	}
+
+	async fn parse_entry_inner(&mut self, ctx: &mut Stk) -> ParseResult<Entry> {
 		let token = self.peek();
 		match token.kind {
 			t!("BREAK") => {

core/src/syn/v2/parser/test/limit.rs

@@ -0,0 +1,198 @@
+use reblessive::Stack;
+
+use crate::syn::v2::parser::Parser;
+
+#[test]
+fn object_depth() {
+	let mut stack = Stack::new();
+
+	let source = r#"
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+						}
+					}
+				}
+			}
+		}
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_object_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect("recursion limit of 5 couldn't parse 5 deep object");
+
+	let source = r#"
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+							e: {
+							}
+						}
+					}
+				}
+			}
+		}
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_object_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect_err("recursion limit of 5 didn't trigger on 6 deep object");
+}
+
+#[test]
+fn object_depth_succeed_then_fail() {
+	let mut stack = Stack::new();
+	let source = r#"
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+						}
+					}
+				}
+			}
+		};
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+						}
+					}
+				}
+			}
+		};
+	"#;
+
+	let mut parser = Parser::new(source.as_bytes()).with_object_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect("recursion limit of 5 couldn't parse 5 deep object");
+
+	let mut stack = Stack::new();
+	let source = r#"
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+						}
+					}
+				}
+			}
+		};
+		RETURN {
+			a: {
+				b: {
+					c: {
+						d: {
+							e: {
+							}
+						}
+					}
+				}
+			}
+		};
+	"#;
+
+	let mut parser = Parser::new(source.as_bytes()).with_object_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect_err("recursion limit of 5 didn't trigger on 6 deep object");
+}
+
+#[test]
+fn query_depth_subquery() {
+	let mut stack = Stack::new();
+
+	let source = r#"
+		RETURN select (select (select ( select foo from bar ) from bar ) from bar) from bar
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect("recursion limit of 5 couldn't parse 5 deep query");
+
+	let source = r#"
+		RETURN select (select (select ( select (select foo from bar) from bar ) from bar ) from bar) from bar
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect_err("recursion limit of 5 didn't trigger on 6 deep query");
+}
+
+#[test]
+fn query_depth_block() {
+	let mut stack = Stack::new();
+
+	let source = r#"
+	{
+		{
+			{
+				{
+					RETURN "foo";
+				}
+			}
+		}
+	}
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect("recursion limit of 5 couldn't parse 5 deep query");
+
+	let source = r#"
+	{
+		{
+			{
+				{
+					{
+						RETURN "foo";
+					}
+				}
+			}
+		}
+	}
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect_err("recursion limit of 5 didn't trigger on 6 deep query");
+}
+
+#[test]
+fn query_depth_if() {
+	let mut stack = Stack::new();
+
+	let source = r#"
+        IF IF IF IF IF true THEN false END { false } { false } { false } { false }
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect("recursion limit of 5 couldn't parse 5 deep query");
+
+	let source = r#"
+        IF IF IF IF IF IF true THEN false END { false } { false } { false } { false } { false }
+	"#;
+	let mut parser = Parser::new(source.as_bytes()).with_query_recursion_limit(5);
+	stack
+		.enter(|stk| parser.parse_query(stk))
+		.finish()
+		.expect_err("recursion limit of 5 didn't trigger on 6 deep query");
+}

core/src/syn/v2/parser/test/mod.rs

@@ -1,3 +1,4 @@
+mod limit;
 mod stmt;
 mod streaming;
 mod value;