pgevolve_core/parse/
statement.rs

1//! Classify a top-level `pg_query` statement node into the v0.1 whitelist.
2//!
3//! Anything outside the whitelist is rejected with [`ParseError::UnsupportedObjectKind`]
4//! so that source-loading fails loudly instead of silently dropping unsupported DDL.
5
6use pg_query::NodeEnum;
7use pg_query::protobuf;
8use pg_query::protobuf::ObjectType;
9
10use crate::parse::error::{ParseError, SourceLocation};
11
12/// One supported top-level statement kind. Each variant carries the typed protobuf
13/// message that the corresponding builder will consume.
14#[derive(Debug, Clone)]
15pub enum Statement {
16    /// `CREATE SCHEMA ...`.
17    CreateSchema(protobuf::CreateSchemaStmt),
18    /// `CREATE TABLE ...`.
19    CreateTable(protobuf::CreateStmt),
20    /// `CREATE SEQUENCE ...`.
21    CreateSequence(protobuf::CreateSeqStmt),
22    /// `CREATE [UNIQUE] INDEX ...`.
23    CreateIndex(protobuf::IndexStmt),
24    /// `ALTER TABLE ...` — only `ADD CONSTRAINT FOREIGN KEY` is allowed in source DDL.
25    AlterTable(protobuf::AlterTableStmt),
26    /// `COMMENT ON ...`.
27    Comment(protobuf::CommentStmt),
28    /// `CREATE [OR REPLACE] VIEW ...`.
29    CreateView(protobuf::ViewStmt),
30    /// `CREATE MATERIALIZED VIEW ...`.
31    CreateMaterializedView(protobuf::CreateTableAsStmt),
32    /// `CREATE TYPE ... AS ENUM (...)`.
33    CreateEnum(protobuf::CreateEnumStmt),
34    /// `CREATE DOMAIN ... AS ...`.
35    CreateDomain(protobuf::CreateDomainStmt),
36    /// `CREATE TYPE ... AS (...)` (composite).
37    CreateCompositeType(protobuf::CompositeTypeStmt),
38    /// `CREATE TYPE ... AS RANGE (...)`.
39    CreateRange(protobuf::CreateRangeStmt),
40    /// `CREATE [OR REPLACE] FUNCTION ...`.
41    CreateFunction(protobuf::CreateFunctionStmt),
42    /// `CREATE [OR REPLACE] PROCEDURE ...`.
43    CreateProcedure(protobuf::CreateFunctionStmt),
44    /// `CREATE EXTENSION ...`.
45    CreateExtension(protobuf::CreateExtensionStmt),
46    /// `CREATE [CONSTRAINT] TRIGGER ...`.
47    CreateTrigger(protobuf::CreateTrigStmt),
48    /// `ALTER TABLE parent ATTACH PARTITION child FOR VALUES ...`.
49    AlterTableAttachPartition(protobuf::AlterTableStmt),
50    /// `GRANT priv ON obj TO grantee` — object-level grant (not REVOKE, not role grant).
51    Grant(protobuf::GrantStmt),
52    /// `ALTER <kind> name OWNER TO role`.
53    AlterOwner(protobuf::AlterOwnerStmt),
54    /// `ALTER DEFAULT PRIVILEGES ... GRANT ...`.
55    AlterDefaultPrivileges(protobuf::AlterDefaultPrivilegesStmt),
56    /// `CREATE POLICY name ON table ...`.
57    CreatePolicy(protobuf::CreatePolicyStmt),
58    /// `CREATE PUBLICATION name ...`.
59    CreatePublication(protobuf::CreatePublicationStmt),
60    /// `ALTER PUBLICATION name ...`.
61    AlterPublication(protobuf::AlterPublicationStmt),
62    /// `CREATE SUBSCRIPTION name CONNECTION ... PUBLICATION ...`.
63    CreateSubscription(protobuf::CreateSubscriptionStmt),
64    /// `ALTER SUBSCRIPTION name ...`.
65    AlterSubscription(protobuf::AlterSubscriptionStmt),
66    /// `CREATE STATISTICS name … ON … FROM …`.
67    CreateStatistics(protobuf::CreateStatsStmt),
68    /// `ALTER STATISTICS name SET STATISTICS n`.
69    AlterStatistics(protobuf::AlterStatsStmt),
70    /// `CREATE COLLATION qname (provider = …, locale = …, …)`.
71    CreateCollation(protobuf::DefineStmt),
72    /// `CREATE AGGREGATE qname(args) (SFUNC = …, STYPE = …, …)`.
73    CreateAggregate(protobuf::DefineStmt),
74    /// `CREATE EVENT TRIGGER name ON event …`.
75    CreateEventTrigger(protobuf::CreateEventTrigStmt),
76    /// `ALTER EVENT TRIGGER name {ENABLE|DISABLE|ENABLE REPLICA|ENABLE ALWAYS}`.
77    AlterEventTrigger(protobuf::AlterEventTrigStmt),
78    /// `CREATE CAST (src AS tgt) WITH FUNCTION …` / `WITH INOUT` / `WITHOUT FUNCTION`.
79    CreateCast(protobuf::CreateCastStmt),
80}
81
82impl Statement {
83    /// Classify a node into the supported whitelist, or return
84    /// [`ParseError::UnsupportedObjectKind`] for anything else.
85    #[allow(clippy::too_many_lines)] // one arm per supported `NodeEnum` variant; the dispatch table is the function.
86    pub fn classify(node: NodeEnum, location: SourceLocation) -> Result<Self, ParseError> {
87        match node {
88            NodeEnum::CreateSchemaStmt(s) => Ok(Self::CreateSchema(s)),
89            NodeEnum::CreateStmt(s) => Ok(Self::CreateTable(s)),
90            NodeEnum::CreateSeqStmt(s) => Ok(Self::CreateSequence(s)),
91            NodeEnum::IndexStmt(s) => Ok(Self::CreateIndex(*s)),
92            NodeEnum::AlterTableStmt(s) => {
93                if is_attach_partition_stmt(&s) {
94                    Ok(Self::AlterTableAttachPartition(s))
95                } else {
96                    Ok(Self::AlterTable(s))
97                }
98            }
99            NodeEnum::CommentStmt(s) => Ok(Self::Comment(*s)),
100            NodeEnum::ViewStmt(s) => Ok(Self::CreateView(*s)),
101            NodeEnum::CreateEnumStmt(s) => Ok(Self::CreateEnum(s)),
102            NodeEnum::CreateDomainStmt(s) => Ok(Self::CreateDomain(*s)),
103            NodeEnum::CompositeTypeStmt(s) => Ok(Self::CreateCompositeType(s)),
104            NodeEnum::CreateRangeStmt(s) => Ok(Self::CreateRange(s)),
105            NodeEnum::CreateFunctionStmt(s) => {
106                if s.is_procedure {
107                    Ok(Self::CreateProcedure(*s))
108                } else {
109                    Ok(Self::CreateFunction(*s))
110                }
111            }
112            NodeEnum::CreateExtensionStmt(s) => Ok(Self::CreateExtension(s)),
113            NodeEnum::CreateTrigStmt(s) => Ok(Self::CreateTrigger(*s)),
114            NodeEnum::GrantStmt(s) => Ok(Self::Grant(s)),
115            NodeEnum::AlterOwnerStmt(s) => Ok(Self::AlterOwner(*s)),
116            NodeEnum::AlterDefaultPrivilegesStmt(s) => Ok(Self::AlterDefaultPrivileges(s)),
117            NodeEnum::CreatePolicyStmt(s) => Ok(Self::CreatePolicy(*s)),
118            NodeEnum::CreatePublicationStmt(s) => Ok(Self::CreatePublication(s)),
119            NodeEnum::AlterPublicationStmt(s) => Ok(Self::AlterPublication(s)),
120            NodeEnum::CreateSubscriptionStmt(s) => Ok(Self::CreateSubscription(s)),
121            NodeEnum::AlterSubscriptionStmt(s) => Ok(Self::AlterSubscription(s)),
122            NodeEnum::CreateStatsStmt(s) => Ok(Self::CreateStatistics(s)),
123            NodeEnum::AlterStatsStmt(s) => Ok(Self::AlterStatistics(*s)),
124            NodeEnum::CreateEventTrigStmt(s) => Ok(Self::CreateEventTrigger(s)),
125            NodeEnum::AlterEventTrigStmt(s) => Ok(Self::AlterEventTrigger(s)),
126            NodeEnum::CreateCastStmt(s) => Ok(Self::CreateCast(s)),
127            NodeEnum::DefineStmt(s) => {
128                let kind = ObjectType::try_from(s.kind).unwrap_or(ObjectType::Undefined);
129                match kind {
130                    ObjectType::ObjectCollation => Ok(Self::CreateCollation(s)),
131                    ObjectType::ObjectAggregate => Ok(Self::CreateAggregate(s)),
132                    _ => Err(unsupported(location, "CREATE OPERATOR/etc.")),
133                }
134            }
135            NodeEnum::RenameStmt(s) => {
136                use pg_query::protobuf::ObjectType;
137                let rename_type =
138                    ObjectType::try_from(s.rename_type).unwrap_or(ObjectType::Undefined);
139                if matches!(rename_type, ObjectType::ObjectPublication) {
140                    return Err(ParseError::Structural {
141                        location,
142                        message: "ALTER PUBLICATION … RENAME TO is not supported in pgevolve \
143                                  (pgevolve never models renames)"
144                            .into(),
145                    });
146                }
147                if matches!(rename_type, ObjectType::ObjectSubscription) {
148                    // Recover the subscription name for the error (subname is in
149                    // RenameStmt.relation for subscriptions).
150                    let sub_name = s
151                        .relation
152                        .as_ref()
153                        .map_or_else(|| String::from("<unknown>"), |r| r.relname.clone());
154                    let id = crate::identifier::Identifier::from_unquoted(&sub_name)
155                        .unwrap_or_else(|_| {
156                            crate::identifier::Identifier::from_unquoted("subscription")
157                                .expect("static identifier")
158                        });
159                    return Err(ParseError::SubscriptionRenameNotSupported(id, location));
160                }
161                if matches!(rename_type, ObjectType::ObjectEventTrigger) {
162                    // RenameStmt for an event trigger encodes the (old) name in
163                    // `s.object` as a bare String node.
164                    let name = s
165                        .object
166                        .as_ref()
167                        .and_then(|o| o.node.as_ref())
168                        .and_then(|n| match n {
169                            NodeEnum::String(st) => Some(st.sval.clone()),
170                            _ => None,
171                        })
172                        .unwrap_or_else(|| String::from("<unknown>"));
173                    let id =
174                        crate::identifier::Identifier::from_unquoted(&name).unwrap_or_else(|_| {
175                            crate::identifier::Identifier::from_unquoted("event_trigger")
176                                .expect("static identifier")
177                        });
178                    return Err(ParseError::EventTriggerRenameNotSupported(id, location));
179                }
180                if matches!(rename_type, ObjectType::ObjectAggregate) {
181                    return Err(ParseError::Structural {
182                        location,
183                        message: "ALTER AGGREGATE … RENAME TO is not supported in pgevolve \
184                                  (pgevolve never models renames)"
185                            .into(),
186                    });
187                }
188                if matches!(rename_type, ObjectType::ObjectStatisticExt) {
189                    // RenameStmt for statistics encodes the name in `s.subname` (the
190                    // new name) and `s.relation` (the old qualified name).
191                    let schema = s
192                        .relation
193                        .as_ref()
194                        .map_or_else(String::new, |r| r.schemaname.clone());
195                    let name = s
196                        .relation
197                        .as_ref()
198                        .map_or_else(|| String::from("<unknown>"), |r| r.relname.clone());
199                    let schema_id = crate::identifier::Identifier::from_unquoted(&schema)
200                        .unwrap_or_else(|_| {
201                            crate::identifier::Identifier::from_unquoted("unknown")
202                                .expect("static identifier")
203                        });
204                    let name_id = crate::identifier::Identifier::from_unquoted(&name)
205                        .unwrap_or_else(|_| {
206                            crate::identifier::Identifier::from_unquoted("statistic")
207                                .expect("static identifier")
208                        });
209                    let qname = crate::identifier::QualifiedName::new(schema_id, name_id);
210                    return Err(ParseError::StatisticRenameNotSupported(qname, location));
211                }
212                Err(unsupported(location, "RENAME"))
213            }
214            NodeEnum::AlterPolicyStmt(_) => Err(ParseError::Structural {
215                location,
216                message: "ALTER POLICY in source is not supported — policy modifications \
217                          happen via diff; use CREATE POLICY in source"
218                    .into(),
219            }),
220            NodeEnum::DropStmt(s) => {
221                let kind = ObjectType::try_from(s.remove_type).unwrap_or(ObjectType::Undefined);
222                if matches!(kind, ObjectType::ObjectPolicy) {
223                    return Err(ParseError::Structural {
224                        location,
225                        message: "DROP POLICY in source is not supported — drops happen \
226                                  via diff"
227                            .into(),
228                    });
229                }
230                if matches!(kind, ObjectType::ObjectAggregate) {
231                    return Err(ParseError::Structural {
232                        location,
233                        message: "DROP AGGREGATE in source is not supported — drops happen \
234                                  via diff"
235                            .into(),
236                    });
237                }
238                if matches!(kind, ObjectType::ObjectCast) {
239                    return Err(ParseError::Structural {
240                        location,
241                        message: "DROP CAST in source is not supported — drops happen via diff"
242                            .into(),
243                    });
244                }
245                Err(unsupported(location, "DROP"))
246            }
247            NodeEnum::AlterExtensionStmt(_) => Err(ParseError::Structural {
248                location,
249                message: "ALTER EXTENSION is not supported in source files — \
250                          declare the desired state via CREATE EXTENSION"
251                    .into(),
252            }),
253            NodeEnum::CreateTableAsStmt(s) => {
254                // `CREATE TABLE ... AS SELECT` and `CREATE MATERIALIZED VIEW`
255                // both arrive as CreateTableAsStmt. Route by the objtype field.
256                match ObjectType::try_from(s.objtype) {
257                    Ok(ObjectType::ObjectMatview) => Ok(Self::CreateMaterializedView(*s)),
258                    _ => Err(unsupported(location, "CREATE TABLE AS SELECT")),
259                }
260            }
261            other => Err(unsupported(location, friendly_kind(&other))),
262        }
263    }
264}
265
266/// Returns `true` when the `AlterTableStmt` is exactly one `ATTACH PARTITION`
267/// sub-command so the classifier can route it to the dedicated variant.
268fn is_attach_partition_stmt(stmt: &protobuf::AlterTableStmt) -> bool {
269    use pg_query::protobuf::AlterTableType;
270    if stmt.cmds.len() != 1 {
271        return false;
272    }
273    match &stmt.cmds[0].node {
274        Some(NodeEnum::AlterTableCmd(c)) => AlterTableType::try_from(c.subtype)
275            .ok()
276            .is_some_and(|t| matches!(t, AlterTableType::AtAttachPartition)),
277        _ => false,
278    }
279}
280
281const fn unsupported(location: SourceLocation, kind: &'static str) -> ParseError {
282    ParseError::UnsupportedObjectKind { location, kind }
283}
284
285/// Translate non-whitelisted node kinds to a human-readable label for diagnostics.
286#[allow(clippy::match_same_arms)]
287const fn friendly_kind(node: &NodeEnum) -> &'static str {
288    match node {
289        NodeEnum::ViewStmt(_) => "CREATE VIEW", // never reached — routed above
290        NodeEnum::CreateEnumStmt(_) => "CREATE TYPE ... AS ENUM", // never reached — routed above
291        NodeEnum::CreateFunctionStmt(_) => "CREATE FUNCTION/PROCEDURE", // never reached — routed above
292        NodeEnum::CreateTrigStmt(_) => "CREATE TRIGGER", // never reached — routed above
293        NodeEnum::CreateRangeStmt(_) => "CREATE TYPE ... AS RANGE", // never reached — routed above
294        NodeEnum::CreateExtensionStmt(_) => "CREATE EXTENSION", // never reached — routed above
295        NodeEnum::CreatePolicyStmt(_) => "CREATE POLICY", // never reached — routed above
296        NodeEnum::CreateForeignTableStmt(_) => "CREATE FOREIGN TABLE",
297        NodeEnum::CreateFdwStmt(_) => "CREATE FOREIGN DATA WRAPPER",
298        NodeEnum::CreateForeignServerStmt(_) => "CREATE FOREIGN SERVER",
299        NodeEnum::CreateRoleStmt(_) => "CREATE ROLE",
300        NodeEnum::GrantStmt(_) => "GRANT/REVOKE", // never reached — routed above
301        NodeEnum::GrantRoleStmt(_) => "GRANT/REVOKE ROLE",
302        NodeEnum::CreateTableAsStmt(_) => "CREATE TABLE AS",
303        NodeEnum::CreateAmStmt(_) => "CREATE ACCESS METHOD",
304        NodeEnum::CreateEventTrigStmt(_) => "CREATE EVENT TRIGGER",
305        NodeEnum::CreateOpClassStmt(_) => "CREATE OPERATOR CLASS",
306        NodeEnum::CreateOpFamilyStmt(_) => "CREATE OPERATOR FAMILY",
307        NodeEnum::CreatePlangStmt(_) => "CREATE LANGUAGE",
308        NodeEnum::CreateStatsStmt(_) => "CREATE STATISTICS",
309        NodeEnum::CreateUserMappingStmt(_) => "CREATE USER MAPPING",
310        NodeEnum::CreateTableSpaceStmt(_) => "CREATE TABLESPACE",
311        NodeEnum::CreatedbStmt(_) => "CREATE DATABASE",
312        NodeEnum::DefineStmt(_) => "CREATE AGGREGATE/OPERATOR/etc.",
313        NodeEnum::RuleStmt(_) => "CREATE RULE",
314        NodeEnum::DropStmt(_) => "DROP",
315        NodeEnum::TruncateStmt(_) => "TRUNCATE",
316        NodeEnum::SelectStmt(_) => "SELECT",
317        NodeEnum::InsertStmt(_) => "INSERT",
318        NodeEnum::UpdateStmt(_) => "UPDATE",
319        NodeEnum::DeleteStmt(_) => "DELETE",
320        NodeEnum::CopyStmt(_) => "COPY",
321        NodeEnum::TransactionStmt(_) => "BEGIN/COMMIT/ROLLBACK",
322        _ => "this statement kind",
323    }
324}
325
326#[cfg(test)]
327mod tests {
328    use super::*;
329    use std::path::PathBuf;
330
331    fn loc() -> SourceLocation {
332        SourceLocation::new(PathBuf::from("test.sql"), 1, 1)
333    }
334
335    fn first_node(sql: &str) -> NodeEnum {
336        let parsed = pg_query::parse(sql).expect("pg_query parses");
337        parsed
338            .protobuf
339            .stmts
340            .into_iter()
341            .next()
342            .and_then(|raw| raw.stmt)
343            .and_then(|n| n.node)
344            .expect("at least one statement")
345    }
346
347    #[test]
348    fn create_table_classifies() {
349        let node = first_node("CREATE TABLE app.users (id integer);");
350        let stmt = Statement::classify(node, loc()).unwrap();
351        assert!(matches!(stmt, Statement::CreateTable(_)));
352    }
353
354    #[test]
355    fn create_schema_classifies() {
356        let node = first_node("CREATE SCHEMA app;");
357        let stmt = Statement::classify(node, loc()).unwrap();
358        assert!(matches!(stmt, Statement::CreateSchema(_)));
359    }
360
361    #[test]
362    fn create_index_classifies() {
363        let node = first_node("CREATE INDEX users_email_idx ON app.users (email);");
364        let stmt = Statement::classify(node, loc()).unwrap();
365        assert!(matches!(stmt, Statement::CreateIndex(_)));
366    }
367
368    #[test]
369    fn create_sequence_classifies() {
370        let node = first_node("CREATE SEQUENCE app.seq1;");
371        let stmt = Statement::classify(node, loc()).unwrap();
372        assert!(matches!(stmt, Statement::CreateSequence(_)));
373    }
374
375    #[test]
376    fn alter_table_classifies() {
377        let node = first_node(
378            "ALTER TABLE app.invoices ADD CONSTRAINT fk1 FOREIGN KEY (cid) REFERENCES app.c(id);",
379        );
380        let stmt = Statement::classify(node, loc()).unwrap();
381        assert!(matches!(stmt, Statement::AlterTable(_)));
382    }
383
384    #[test]
385    fn comment_classifies() {
386        let node = first_node("COMMENT ON TABLE app.users IS 'people';");
387        let stmt = Statement::classify(node, loc()).unwrap();
388        assert!(matches!(stmt, Statement::Comment(_)));
389    }
390
391    #[test]
392    fn create_view_classifies() {
393        let node = first_node("CREATE VIEW app.v AS SELECT 1;");
394        let stmt = Statement::classify(node, loc()).unwrap();
395        assert!(matches!(stmt, Statement::CreateView(_)));
396    }
397
398    #[test]
399    fn create_materialized_view_classifies() {
400        let node = first_node(
401            "CREATE MATERIALIZED VIEW app.mv AS SELECT count(*) FROM app.t WITH NO DATA;",
402        );
403        let stmt = Statement::classify(node, loc()).unwrap();
404        assert!(matches!(stmt, Statement::CreateMaterializedView(_)));
405    }
406
407    #[test]
408    fn create_table_as_select_unsupported() {
409        let node = first_node("CREATE TABLE app.t2 AS SELECT 1;");
410        let err = Statement::classify(node, loc()).unwrap_err();
411        assert!(matches!(err, ParseError::UnsupportedObjectKind { .. }));
412    }
413
414    #[test]
415    fn create_function_classifies() {
416        let node =
417            first_node("CREATE FUNCTION app.f() RETURNS integer AS $$ SELECT 1; $$ LANGUAGE sql;");
418        let stmt = Statement::classify(node, loc()).unwrap();
419        assert!(matches!(stmt, Statement::CreateFunction(_)));
420    }
421
422    #[test]
423    fn create_procedure_classifies() {
424        let node =
425            first_node("CREATE PROCEDURE app.p() LANGUAGE plpgsql AS $$ BEGIN NULL; END $$;");
426        let stmt = Statement::classify(node, loc()).unwrap();
427        assert!(matches!(stmt, Statement::CreateProcedure(_)));
428    }
429
430    #[test]
431    fn create_extension_classifies() {
432        let node = first_node("CREATE EXTENSION pgcrypto;");
433        let stmt = Statement::classify(node, loc()).unwrap();
434        assert!(matches!(stmt, Statement::CreateExtension(_)));
435    }
436
437    #[test]
438    fn alter_extension_rejected() {
439        let node = first_node("ALTER EXTENSION pgcrypto UPDATE;");
440        let err = Statement::classify(node, loc()).unwrap_err();
441        assert!(matches!(err, ParseError::Structural { .. }));
442    }
443
444    #[test]
445    fn select_unsupported() {
446        let node = first_node("SELECT 1;");
447        let err = Statement::classify(node, loc()).unwrap_err();
448        assert!(matches!(err, ParseError::UnsupportedObjectKind { .. }));
449    }
450}
pgevolve_core/parse/statement.rs

pgevolve_core/parse/
statement.rs
