Introduce get_reserved_grantees_types to distinguish keyword vs identifier

Author: aharpervc

src/dialect/mod.rs

@@ -49,7 +49,7 @@ pub use self::postgresql::PostgreSqlDialect;
 pub use self::redshift::RedshiftSqlDialect;
 pub use self::snowflake::SnowflakeDialect;
 pub use self::sqlite::SQLiteDialect;
-use crate::ast::{ColumnOption, Expr, Statement};
+use crate::ast::{ColumnOption, Expr, GranteesType, Statement};
 pub use crate::keywords;
 use crate::keywords::Keyword;
 use crate::parser::{Parser, ParserError};
@@ -894,6 +894,11 @@ pub trait Dialect: Debug + Any {
         &[]
     }
 
+    /// Returns grantee types that should be treated as identifiers
+    fn get_reserved_grantees_types(&self) -> &[GranteesType] {
+        &[]
+    }
+
     /// Returns true if this dialect supports the `TABLESAMPLE` option
     /// before the table alias option. For example:
     ///

src/dialect/mssql.rs

@@ -17,7 +17,8 @@
 
 use crate::ast::helpers::attached_token::AttachedToken;
 use crate::ast::{
-    BeginEndStatements, ConditionalStatementBlock, ConditionalStatements, IfStatement, Statement,
+    BeginEndStatements, ConditionalStatementBlock, ConditionalStatements, GranteesType,
+    IfStatement, Statement,
 };
 use crate::dialect::Dialect;
 use crate::keywords::{self, Keyword};
@@ -122,6 +123,11 @@ impl Dialect for MsSqlDialect {
         true
     }
 
+    /// See <https://learn.microsoft.com/en-us/sql/relational-databases/security/authentication-access/server-level-roles>
+    fn get_reserved_grantees_types(&self) -> &[GranteesType] {
+        &[GranteesType::Public]
+    }
+
     fn is_column_alias(&self, kw: &Keyword, _parser: &mut Parser) -> bool {
         !keywords::RESERVED_FOR_COLUMN_ALIAS.contains(kw) && !RESERVED_FOR_COLUMN_ALIAS.contains(kw)
     }

src/parser/mod.rs

@@ -13025,30 +13025,36 @@ impl<'a> Parser<'a> {
         let mut values = vec![];
         let mut grantee_type = GranteesType::None;
         loop {
-            grantee_type = if self.parse_keyword(Keyword::ROLE) {
+            let new_grantee_type = if self.parse_keyword(Keyword::ROLE) {
                 GranteesType::Role
             } else if self.parse_keyword(Keyword::USER) {
                 GranteesType::User
             } else if self.parse_keyword(Keyword::SHARE) {
                 GranteesType::Share
             } else if self.parse_keyword(Keyword::GROUP) {
                 GranteesType::Group
+            } else if self.parse_keyword(Keyword::PUBLIC) {
+                GranteesType::Public
             } else if self.parse_keywords(&[Keyword::DATABASE, Keyword::ROLE]) {
                 GranteesType::DatabaseRole
             } else if self.parse_keywords(&[Keyword::APPLICATION, Keyword::ROLE]) {
                 GranteesType::ApplicationRole
             } else if self.parse_keyword(Keyword::APPLICATION) {
                 GranteesType::Application
-            } else if self.peek_keyword(Keyword::PUBLIC) {
-                if dialect_of!(self is MsSqlDialect) {
-                    grantee_type
-                } else {
-                    GranteesType::Public
-                }
             } else {
-                grantee_type // keep from previous iteraton, if not specified
+                grantee_type.clone() // keep from previous iteraton, if not specified
             };
 
+            if self
+                .dialect
+                .get_reserved_grantees_types()
+                .contains(&new_grantee_type)
+            {
+                self.prev_token();
+            } else {
+                grantee_type = new_grantee_type;
+            }
+
             let grantee = if grantee_type == GranteesType::Public {
                 Grantee {
                     grantee_type: grantee_type.clone(),