Add initial PG18 support

Author: JelteF

.github/workflows/build_and_test.yaml

@@ -52,6 +52,8 @@ jobs:
           type: ReleaseStatic
         - version: REL_17_STABLE
           type: Debug
+        - version: REL_18_BETA1
+          type: Release
 
         # Not enabled for now (waiting for April 2025 code freeze)
         # - version: master

Makefile.global

@@ -7,7 +7,7 @@ $(error Minimum version of PostgreSQL required is $(PG_MIN_VER) (but have $(PG_V
 endif
 
 # If you want to test with an unsupported PG version you can pass a different value to make
-PG_MAX_VER ?= 17
+PG_MAX_VER ?= 18
 ifeq ($(shell expr "$(PG_MAX_VER)" \>=  "$(PG_VER)"), 0)
 $(error Maximum supported version of PostgreSQL is $(PG_MAX_VER) (but have $(PG_VER)))
 endif

include/pgduckdb/pg/declarations.hpp

@@ -81,4 +81,6 @@ struct TupleQueueReader;
 struct PlanState;
 
 struct Plan;
+
+struct ExplainState;
 }

include/pgduckdb/pg/explain.hpp

@@ -0,0 +1,11 @@
+#include "pgduckdb/pg/declarations.hpp"
+#include "duckdb/common/enums/explain_format.hpp"
+
+namespace pgduckdb::pg {
+void
+ExplainPropertyText(const char *qlabel, const char *value, ExplainState *es);
+
+duckdb::ExplainFormat DuckdbExplainFormat(ExplainState *es);
+
+bool IsExplainAnalyze(ExplainState *es);
+}

include/pgduckdb/pg/locale.hpp

@@ -0,0 +1,6 @@
+#include "pgduckdb/pg/declarations.hpp"
+
+namespace pgduckdb::pg {
+bool IsCLocale(Oid collation_id);
+}
+

include/pgduckdb/vendor/pg_ruleutils.h

@@ -43,6 +43,13 @@ extern List *pgduckdb_set_deparse_context_plan(List *dpcontext,
 									  struct Plan *plan, List *ancestors);
 extern List *pgduckdb_select_rtable_names_for_explain(List *rtable,
 											 Bitmapset *rels_used);
+#if PG_VERSION_NUM >= 180000
+extern char *get_window_frame_options_for_explain(int frameOptions,
+												  Node *startOffset,
+												  Node *endOffset,
+												  List *dpcontext,
+												  bool forceprefix);
+#endif
 extern char *pgduckdb_generate_collation_name(Oid collid);
 extern char *pgduckdb_generate_opclass_name(Oid opclass);
 extern char *pgduckdb_get_range_partbound_string(List *bound_datums);

src/pg/explain.cpp

@@ -0,0 +1,32 @@
+#include "pgduckdb/pg/explain.hpp"
+#include "pgduckdb/pgduckdb_utils.hpp"
+
+extern "C" {
+#include "postgres.h"
+
+#if PG_VERSION_NUM >= 180000
+#include "commands/explain_format.h"
+#include "commands/explain_state.h"
+#else
+#include "commands/explain.h"
+#endif
+
+}
+
+namespace pgduckdb::pg {
+void
+ExplainPropertyText(const char *qlabel, const char *value, ExplainState *es) {
+	PostgresFunctionGuard(::ExplainPropertyText, qlabel, value, es);
+}
+
+duckdb::ExplainFormat DuckdbExplainFormat(ExplainState *es) {
+	if (es->format == EXPLAIN_FORMAT_JSON)
+		return duckdb::ExplainFormat::JSON;
+
+	return duckdb::ExplainFormat::DEFAULT;
+}
+
+bool IsExplainAnalyze(ExplainState *es) {
+	return es->analyze;
+}
+}

src/pg/locale.cpp

@@ -0,0 +1,31 @@
+#include "pgduckdb/pg/locale.hpp"
+
+extern "C" {
+#include "postgres.h"
+}
+
+/*
+ * Needs to be done outside of 'extern "C"' block AND before including
+ * pg_locale.h. Otherwise you get many compilation errors about templates being
+ * used in C linkage. It also needs to be done after including postgres.h,
+ * because otherwise USE_ICU does not exist.
+ */
+#ifdef USE_ICU
+#include <unicode/ucol.h>
+#endif
+
+extern "C" {
+#include "utils/pg_locale.h"
+}
+
+namespace pgduckdb::pg {
+
+bool IsCLocale(Oid collation_id) {
+#if PG_VERSION_NUM >= 180000
+	return pg_newlocale_from_collation(collation_id)->collate_is_c;
+#else
+	return lc_ctype_is_c(collation_id);
+#endif
+}
+
+}

src/pg/relations.cpp

@@ -56,7 +56,7 @@ GetAttName(const Form_pg_attribute att) {
 
 Form_pg_attribute
 GetAttr(const TupleDesc tupleDesc, int i) {
-	return &tupleDesc->attrs[i];
+	return TupleDescAttr(tupleDesc, i);
 }
 
 bool

src/pgduckdb_ddl.cpp

@@ -349,7 +349,11 @@ DuckdbHandleDDL(PlannedStmt *pstmt, const char *query_string, ParamListInfo para
 			 */
 			MemoryContext view_query_context = GetMemoryChunkContext(stmt->into->viewQuery);
 			MemoryContextSwitchTo(view_query_context);
+#if PG_VERSION_NUM >= 180000
+			stmt->into->viewQuery = (Query *)copyObjectImpl(stmt->query);
+#else
 			stmt->into->viewQuery = (Node *)copyObjectImpl(stmt->query);
+#endif
 			MemoryContextSwitchTo(oldcontext);
 		}
 	} else if (IsA(parsetree, RefreshMatViewStmt)) {