Merge branch 'main' into mysql-users

README.md

@@ -100,6 +100,23 @@ similar semantics are represented with the same AST. We welcome PRs to fix such
 issues and distinguish different syntaxes in the AST.
 
 
+## WIP: Extracting source locations from AST nodes
+
+This crate allows recovering source locations from AST nodes via the [Spanned](https://docs.rs/sqlparser/latest/sqlparser/ast/trait.Spanned.html) trait, which can be used for advanced diagnostics tooling. Note that this feature is a work in progress and many nodes report missing or inaccurate spans. Please see [this document](./docs/source_spans.md#source-span-contributing-guidelines) for information on how to contribute missing improvements.
+
+```rust
+use sqlparser::ast::Spanned;
+
+// Parse SQL
+let ast = Parser::parse_sql(&GenericDialect, "SELECT A FROM B").unwrap();
+
+// The source span can be retrieved with start and end locations
+assert_eq!(ast[0].span(), Span {
+  start: Location::of(1, 1),
+  end: Location::of(1, 16),
+});
+```
+
 ## SQL compliance
 
 SQL was first standardized in 1987, and revisions of the standard have been
@@ -210,6 +227,18 @@ Our goal as maintainers is to facilitate the integration
 of various features from various contributors, but not to provide the
 implementations ourselves, as we simply don't have the resources.
 
+### Benchmarking
+
+There are several micro benchmarks in the `sqlparser_bench` directory. 
+You can run them with:
+
+```
+git checkout main
+cd sqlparser_bench
+cargo bench
+git checkout <your branch>
+cargo bench
+```
 
 ## Licensing
 

derive/Cargo.toml

@@ -28,6 +28,7 @@ license = "Apache-2.0"
 include = [
     "src/**/*.rs",
     "Cargo.toml",
+    "LICENSE.TXT",
 ]
 edition = "2021"
 

derive/LICENSE.TXT

@@ -0,0 +1 @@
+../LICENSE.TXT

docs/source_spans.md

@@ -0,0 +1,52 @@
+
+## Breaking Changes
+
+These are the current breaking changes introduced by the source spans feature:
+
+#### Added fields for spans (must be added to any existing pattern matches)
+- `Ident` now stores a `Span`
+- `Select`, `With`, `Cte`, `WildcardAdditionalOptions` now store a `TokenWithLocation` 
+
+#### Misc.
+- `TokenWithLocation` stores a full `Span`, rather than just a source location. Users relying on `token.location` should use `token.location.start` instead.
+## Source Span Contributing Guidelines
+
+For contributing source spans improvement in addition to the general [contribution guidelines](../README.md#contributing), please make sure to pay attention to the following:
+
+
+### Source Span Design Considerations
+
+- `Ident` always have correct source spans
+- Downstream breaking change impact is to be as minimal as possible
+- To this end, use recursive merging of spans in favor of storing spans on all nodes
+- Any metadata added to compute spans must not change semantics (Eq, Ord, Hash, etc.)
+
+The primary reason for missing and inaccurate source spans at this time is missing spans of keyword tokens and values in many structures, either due to lack of time or because adding them would break downstream significantly.  
+
+When considering adding support for source spans on a type, consider the impact to consumers of that type and whether your change would require a consumer to do non-trivial changes to their code.
+
+Example of a trivial change
+```rust
+match node {  
+  ast::Query { 
+    field1,
+    field2, 
+    location: _,  // add a new line to ignored location
+}
+```
+
+If adding source spans to a type would require a significant change like wrapping that type or similar, please open an issue to discuss. 
+
+### AST Node Equality and Hashes
+
+When adding tokens to AST nodes, make sure to store them using the [AttachedToken](https://docs.rs/sqlparser/latest/sqlparser/ast/helpers/struct.AttachedToken.html) helper to ensure that semantically equivalent AST nodes always compare as equal and hash to the same value. F.e. `select 5` and `SELECT 5` would compare as different `Select` nodes, if the select token was stored directly. f.e.
+
+```rust
+struct Select {
+    select_token: AttachedToken, // only used for spans
+    /// remaining fields
+    field1,
+    field2,
+    ...
+}
+```

examples/cli.rs

@@ -17,9 +17,11 @@
 
 #![warn(clippy::all)]
 
-/// A small command-line app to run the parser.
-/// Run with `cargo run --example cli`
+//! A small command-line app to run the parser.
+//! Run with `cargo run --example cli`
+
 use std::fs;
+use std::io::{stdin, Read};
 
 use simple_logger::SimpleLogger;
 use sqlparser::dialect::*;
@@ -38,6 +40,9 @@ $ cargo run --example cli FILENAME.sql [--dialectname]
 To print the parse results as JSON:
 $ cargo run --feature json_example --example cli FILENAME.sql [--dialectname]
 
+To read from stdin instead of a file:
+$ cargo run --example cli - [--dialectname]
+
 "#,
     );
 
@@ -57,9 +62,18 @@ $ cargo run --feature json_example --example cli FILENAME.sql [--dialectname]
         s => panic!("Unexpected parameter: {s}"),
     };
 
-    println!("Parsing from file '{}' using {:?}", &filename, dialect);
-    let contents = fs::read_to_string(&filename)
-        .unwrap_or_else(|_| panic!("Unable to read the file {}", &filename));
+    let contents = if filename == "-" {
+        println!("Parsing from stdin using {:?}", dialect);
+        let mut buf = Vec::new();
+        stdin()
+            .read_to_end(&mut buf)
+            .expect("failed to read from stdin");
+        String::from_utf8(buf).expect("stdin content wasn't valid utf8")
+    } else {
+        println!("Parsing from file '{}' using {:?}", &filename, dialect);
+        fs::read_to_string(&filename)
+            .unwrap_or_else(|_| panic!("Unable to read the file {}", &filename))
+    };
     let without_bom = if contents.chars().next().unwrap() as u64 != 0xfeff {
         contents.as_str()
     } else {

sqlparser_bench/Cargo.toml

@@ -17,6 +17,7 @@
 
 [package]
 name = "sqlparser_bench"
+description = "Benchmarks for sqlparser"
 version = "0.1.0"
 authors = ["Dandandan <[email protected]>"]
 edition = "2018"

sqlparser_bench/README.md

@@ -0,0 +1,20 @@
+<!---
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing,
+  software distributed under the License is distributed on an
+  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  KIND, either express or implied.  See the License for the
+  specific language governing permissions and limitations
+  under the License.
+-->
+
+Benchmarks for sqlparser. See [the main README](../README.md) for more information.

sqlparser_bench/benches/sqlparser_bench.rs

@@ -23,24 +23,24 @@ fn basic_queries(c: &mut Criterion) {
     let mut group = c.benchmark_group("sqlparser-rs parsing benchmark");
     let dialect = GenericDialect {};
 
-    let string = "SELECT * FROM table WHERE 1 = 1";
+    let string = "SELECT * FROM my_table WHERE 1 = 1";
     group.bench_function("sqlparser::select", |b| {
-        b.iter(|| Parser::parse_sql(&dialect, string));
+        b.iter(|| Parser::parse_sql(&dialect, string).unwrap());
     });
 
     let with_query = "
         WITH derived AS (
             SELECT MAX(a) AS max_a,
                    COUNT(b) AS b_num,
                    user_id
-            FROM TABLE
+            FROM MY_TABLE
             GROUP BY user_id
         )
-        SELECT * FROM table
+        SELECT * FROM my_table
         LEFT JOIN derived USING (user_id)
     ";
     group.bench_function("sqlparser::with_select", |b| {
-        b.iter(|| Parser::parse_sql(&dialect, with_query));
+        b.iter(|| Parser::parse_sql(&dialect, with_query).unwrap());
     });
 }
 

src/ast/helpers/attached_token.rs

@@ -0,0 +1,82 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use core::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
+use core::fmt::{self, Debug, Formatter};
+use core::hash::{Hash, Hasher};
+
+use crate::tokenizer::{Token, TokenWithLocation};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+#[cfg(feature = "visitor")]
+use sqlparser_derive::{Visit, VisitMut};
+
+/// A wrapper type for attaching tokens to AST nodes that should be ignored in comparisons and hashing.
+/// This should be used when a token is not relevant for semantics, but is still needed for
+/// accurate source location tracking.
+#[derive(Clone)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit, VisitMut))]
+pub struct AttachedToken(pub TokenWithLocation);
+
+impl AttachedToken {
+    pub fn empty() -> Self {
+        AttachedToken(TokenWithLocation::wrap(Token::EOF))
+    }
+}
+
+// Conditional Implementations
+impl Debug for AttachedToken {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+// Blanket Implementations
+impl PartialEq for AttachedToken {
+    fn eq(&self, _: &Self) -> bool {
+        true
+    }
+}
+
+impl Eq for AttachedToken {}
+
+impl PartialOrd for AttachedToken {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for AttachedToken {
+    fn cmp(&self, _: &Self) -> Ordering {
+        Ordering::Equal
+    }
+}
+
+impl Hash for AttachedToken {
+    fn hash<H: Hasher>(&self, _state: &mut H) {
+        // Do nothing
+    }
+}
+
+impl From<TokenWithLocation> for AttachedToken {
+    fn from(value: TokenWithLocation) -> Self {
+        AttachedToken(value)
+    }
+}

src/ast/helpers/mod.rs

@@ -14,5 +14,6 @@
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License.
+pub mod attached_token;
 pub mod stmt_create_table;
 pub mod stmt_data_loading;