reduce false alarms

Author: okbob

expected/plpgsql_check_active-16.out

@@ -601,3 +601,32 @@ select * from plpgsql_check_function('f1');
 ------------------------
 (0 rows)
 
+drop function f1();
+-- do not raise false warning
+create or replace function test_function()
+returns text as $$
+declare s text;
+begin
+  get diagnostics s = PG_CONTEXT;
+  return s;
+end;
+$$ language plpgsql;
+create or replace procedure test_procedure()
+as $$
+begin
+  null;
+end;
+$$ language plpgsql;
+-- should be without any warnings
+select * from plpgsql_check_function('test_function', performance_warnings=>true);
+ plpgsql_check_function 
+------------------------
+(0 rows)
+
+select * from plpgsql_check_function('test_procedure', performance_warnings=>true);
+ plpgsql_check_function 
+------------------------
+(0 rows)
+
+drop function test_function();
+drop procedure test_procedure();

sql/plpgsql_check_active-16.sql

@@ -372,3 +372,29 @@ $$ language plpgsql;
 
 -- should be ok
 select * from plpgsql_check_function('f1');
+
+drop function f1();
+
+-- do not raise false warning
+create or replace function test_function()
+returns text as $$
+declare s text;
+begin
+  get diagnostics s = PG_CONTEXT;
+  return s;
+end;
+$$ language plpgsql;
+
+create or replace procedure test_procedure()
+as $$
+begin
+  null;
+end;
+$$ language plpgsql;
+
+-- should be without any warnings
+select * from plpgsql_check_function('test_function', performance_warnings=>true);
+select * from plpgsql_check_function('test_procedure', performance_warnings=>true);
+
+drop function test_function();
+drop procedure test_procedure();

src/check_function.c

@@ -1234,7 +1234,8 @@ setup_cstate(PLpgSQL_checkstate *cstate,
 
 #endif
 
-									 plpgsql_check_is_eventtriggeroid(cinfo->rettype));
+									 plpgsql_check_is_eventtriggeroid(cinfo->rettype) ||
+									 cinfo->is_procedure);
 	cstate->estate = NULL;
 	cstate->result_info = result_info;
 	cstate->cinfo = cinfo;

src/stmtwalk.c

@@ -13,6 +13,7 @@
 
 #include "access/tupconvert.h"
 #include "catalog/pg_collation.h"
+#include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "nodes/nodeFuncs.h"
 #include "nodes/value.h"
@@ -1237,6 +1238,18 @@ plpgsql_check_stmt(PLpgSQL_checkstate *cstate, PLpgSQL_stmt *stmt, int *closing,
 						PLpgSQL_diag_item *diag_item = (PLpgSQL_diag_item *) lfirst(lc);
 
 						plpgsql_check_target(cstate, diag_item->target, NULL, NULL);
+
+						/*
+						 * Using GET DIAGNOSTICS stack = PG_CONTEXT is like using
+						 * other VOLATILE function.
+						 */
+						if (!cstate->skip_volatility_check &&
+							cstate->cinfo->performance_warnings &&
+							!stmt_getdiag->is_stacked)
+						{
+							if (diag_item->kind == PLPGSQL_GETDIAG_CONTEXT)
+								cstate->volatility = PROVOLATILE_VOLATILE;
+						}
 					}
 
 					if (stmt_getdiag->is_stacked &&