MDEV-10654 add support IN, OUT, INOUT parameter qualifiers for stored functions

Problem: Currently stored function does not support IN/OUT/INOUT parameter qualifiers.
This is needed for Oracle compatibility (sql_mode = ORACLE).

Solution: Implemented parameter qualifier support to CREATE FUNCTION (reference: CREATE PROCEDURE)
Implemented return by reference for OUT/INOUT parameters in execute_function() (reference: execute_procedure())

Files changed:
sql/sql_yacc.yy: Added IN, OUT, INOUT parameter qualifiers for CREATE FUNCTION.
sql/sp_head.cc: Added input and output parameter binding for IN/OUT/INOUT parameters in execute_function() so that OUT/INOUT can return by reference.
sql/share/errmsg-utf8.txt: Added error message to restrict OUT/INOUT parameters while function being called from SQL query.
mysql-test/suite/compat/oracle/t/sp-inout.test: Added test cases
mysql-test/suite/compat/oracle/r/sp-inout.result: Added test results

Reviewed-by: iqbal@hasprime.com

sql/share/errmsg-utf8.txt

@@ -8915,3 +8915,5 @@ ER_PROVIDER_NOT_LOADED
         eng "MariaDB tried to use the %s, but its provider plugin is not loaded"
 ER_JSON_HISTOGRAM_PARSE_FAILED
         eng "Failed to parse histogram for table %s.%s: %s at offset %d."
+ER_SF_OUT_INOUT_ARG_NOT_ALLOWED
+	eng "OUT or INOUT argument %d for function %s is not allowed here"

sql/sp_head.cc

@@ -2079,7 +2079,8 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount,
     /* Arguments must be fixed in Item_func_sp::fix_fields */
     DBUG_ASSERT(argp[arg_no]->fixed());
 
-    if ((err_status= (*func_ctx)->set_parameter(thd, arg_no, &(argp[arg_no]))))
+    err_status= bind_input_param(thd, argp[arg_no], arg_no, *func_ctx, TRUE);
+    if (err_status)
       goto err_with_cleanup;
   }
 
@@ -2202,6 +2203,19 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount,
       my_error(ER_SP_NORETURNEND, MYF(0), m_name.str);
       err_status= TRUE;
     }
+    else
+    {
+      /*
+        Copy back all OUT or INOUT values to the previous frame, or
+        set global user variables
+      */
+      for (arg_no= 0; arg_no < argcount; arg_no++)
+      {
+        err_status= bind_output_param(thd, argp[arg_no], arg_no, octx, *func_ctx);
+        if (err_status)
+          break;
+      }
+    }
   }
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
@@ -2324,52 +2338,11 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
       if (!arg_item)
         break;
 
-      sp_variable *spvar= m_pcont->find_variable(i);
+      err_status= bind_input_param(thd, arg_item, i, nctx, FALSE);
-
+      if (err_status)
-      if (!spvar)
-        continue;
-
-      if (spvar->mode != sp_variable::MODE_IN)
-      {
-        Settable_routine_parameter *srp=
-          arg_item->get_settable_routine_parameter();
-
-        if (!srp)
-        {
-          my_error(ER_SP_NOT_VAR_ARG, MYF(0), i+1, ErrConvDQName(this).ptr());
-          err_status= TRUE;
         break;
     }
 
-        srp->set_required_privilege(spvar->mode == sp_variable::MODE_INOUT);
-      }
-
-      if (spvar->mode == sp_variable::MODE_OUT)
-      {
-        Item_null *null_item= new (thd->mem_root) Item_null(thd);
-        Item *tmp_item= null_item;
-
-        if (!null_item ||
-            nctx->set_parameter(thd, i, &tmp_item))
-        {
-          DBUG_PRINT("error", ("set variable failed"));
-          err_status= TRUE;
-          break;
-        }
-      }
-      else
-      {
-        if (nctx->set_parameter(thd, i, it_args.ref()))
-        {
-          DBUG_PRINT("error", ("set variable 2 failed"));
-          err_status= TRUE;
-          break;
-        }
-      }
-
-      TRANSACT_TRACKER(add_trx_state_from_thd(thd));
-    }
-
     /*
       Okay, got values for all arguments. Close tables that might be used by
       arguments evaluation. If arguments evaluation required prelocking mode,
@@ -2477,32 +2450,10 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
       if (!arg_item)
         break;
 
-      sp_variable *spvar= m_pcont->find_variable(i);
+      err_status= bind_output_param(thd, arg_item, i, octx, nctx);
-
+      if (err_status)
-      if (spvar->mode == sp_variable::MODE_IN)
-        continue;
-
-      Settable_routine_parameter *srp=
-        arg_item->get_settable_routine_parameter();
-
-      DBUG_ASSERT(srp);
-
-      if (srp->set_value(thd, octx, nctx->get_variable_addr(i)))
-      {
-        DBUG_PRINT("error", ("set value failed"));
-        err_status= TRUE;
         break;
     }
-
-      Send_field *out_param_info= new (thd->mem_root) Send_field(thd, nctx->get_parameter(i));
-      out_param_info->db_name= m_db;
-      out_param_info->table_name= m_name;
-      out_param_info->org_table_name= m_name;
-      out_param_info->col_name= spvar->name;
-      out_param_info->org_col_name= spvar->name;
-
-      srp->set_out_param_info(out_param_info);
-    }
   }
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
@@ -2532,6 +2483,112 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
   DBUG_RETURN(err_status);
 }
 
+bool
+sp_head::bind_input_param(THD *thd,
+                          Item *arg_item,
+                          uint arg_no,
+                          sp_rcontext *nctx,
+                          bool is_function)
+{
+  DBUG_ENTER("sp_head::bind_input_param");
+
+  sp_variable *spvar= m_pcont->find_variable(arg_no);
+  if (!spvar)
+    DBUG_RETURN(FALSE);
+
+  if (spvar->mode != sp_variable::MODE_IN)
+  {
+    Settable_routine_parameter *srp=
+      arg_item->get_settable_routine_parameter();
+
+    if (!srp)
+    {
+      my_error(ER_SP_NOT_VAR_ARG, MYF(0), arg_no+1, ErrConvDQName(this).ptr());
+      DBUG_RETURN(TRUE);
+    }
+
+    if (is_function)
+    {
+      /*
+        Check if the function is called from SELECT/INSERT/UPDATE/DELETE query
+        and parameter is OUT or INOUT.
+        If yes, it is an invalid call - throw error.
+      */
+      if (thd->lex->sql_command == SQLCOM_SELECT || 
+          thd->lex->sql_command == SQLCOM_INSERT ||
+          thd->lex->sql_command == SQLCOM_INSERT_SELECT ||
+          thd->lex->sql_command == SQLCOM_UPDATE ||
+          thd->lex->sql_command == SQLCOM_DELETE)
+      {
+        my_error(ER_SF_OUT_INOUT_ARG_NOT_ALLOWED, MYF(0), arg_no+1, m_name.str);
+        DBUG_RETURN(TRUE);
+      }
+    }
+
+    srp->set_required_privilege(spvar->mode == sp_variable::MODE_INOUT);
+  }
+
+  if (spvar->mode == sp_variable::MODE_OUT)
+  {
+    Item_null *null_item= new (thd->mem_root) Item_null(thd);
+    Item *tmp_item= null_item;
+
+    if (!null_item ||
+        nctx->set_parameter(thd, arg_no, &tmp_item))
+    {
+      DBUG_PRINT("error", ("set variable failed"));
+      DBUG_RETURN(TRUE);
+    }
+  }
+  else
+  {
+    if (nctx->set_parameter(thd, arg_no, &arg_item))
+    {
+      DBUG_PRINT("error", ("set variable 2 failed"));
+      DBUG_RETURN(TRUE);
+    }
+  }
+
+  TRANSACT_TRACKER(add_trx_state_from_thd(thd));
+
+  DBUG_RETURN(FALSE);
+}
+
+bool
+sp_head::bind_output_param(THD *thd,
+                           Item *arg_item,
+                           uint arg_no,
+                           sp_rcontext *octx,
+                           sp_rcontext *nctx)
+{
+  DBUG_ENTER("sp_head::bind_output_param");
+
+  sp_variable *spvar= m_pcont->find_variable(arg_no);
+  if (spvar->mode == sp_variable::MODE_IN)
+    DBUG_RETURN(FALSE);
+
+  Settable_routine_parameter *srp=
+    arg_item->get_settable_routine_parameter();
+
+  DBUG_ASSERT(srp);
+
+  if (srp->set_value(thd, octx, nctx->get_variable_addr(arg_no)))
+  {
+    DBUG_PRINT("error", ("set value failed"));
+    DBUG_RETURN(TRUE);
+  }
+
+  Send_field *out_param_info= new (thd->mem_root) Send_field(thd, nctx->get_parameter(arg_no));
+  out_param_info->db_name= m_db;
+  out_param_info->table_name= m_name;
+  out_param_info->org_table_name= m_name;
+  out_param_info->col_name= spvar->name;
+  out_param_info->org_col_name= spvar->name;
+
+  srp->set_out_param_info(out_param_info);
+
+  DBUG_RETURN(FALSE);
+}
 
 /**
   Reset lex during parsing, before we parse a sub statement.

sql/sp_head.h

@@ -505,6 +505,18 @@ private:
                                                sp_assignment_lex *param_lex,
                                                Item_args *parameters);
 
+  bool bind_input_param(THD *thd,
+                        Item *arg_item,
+                        uint arg_no,
+                        sp_rcontext *nctx,
+                        bool is_function);
+
+  bool bind_output_param(THD *thd,
+                         Item *arg_item,
+                         uint arg_no,
+                         sp_rcontext *octx,
+                         sp_rcontext *nctx);
+
 public:
   /**
     Generate a code for an "OPEN cursor" statement.

sql/sql_yacc.yy

@@ -3063,20 +3063,6 @@ sp_param_name:
           }
         ;
 
-sp_param_name_and_type:
-          sp_param_name field_type
-          {
-            if (unlikely(Lex->sp_param_fill_definition($$= $1, $2)))
-              MYSQL_YYABORT;
-          }
-        | sp_param_name ROW_SYM row_type_body
-          {
-            if (unlikely(Lex->sphead->spvar_fill_row(thd, $$= $1, $3)))
-              MYSQL_YYABORT;
-          }
-        | sp_param_name_and_type_anchored
-        ;
-
 /* Stored PROCEDURE parameter declaration list */
 sp_pdparam_list:
           /* Empty */
@@ -18039,6 +18025,20 @@ sp_decl_variable_list_anchored:
           }
         ;
 
+sp_param_name_and_type:
+          sp_param_name field_type
+          {
+            if (unlikely(Lex->sp_param_fill_definition($$= $1, $2)))
+              MYSQL_YYABORT;
+          }
+        | sp_param_name ROW_SYM row_type_body
+          {
+            if (unlikely(Lex->sphead->spvar_fill_row(thd, $$= $1, $3)))
+              MYSQL_YYABORT;
+          }
+        | sp_param_name_and_type_anchored
+        ;
+
 sp_param_name_and_type_anchored:
           sp_param_name TYPE_SYM OF_SYM ident '.' ident
           {
@@ -18913,25 +18913,45 @@ sp_decl_variable_list_anchored:
           }
         ;
 
+sp_param_name_and_type:
+          sp_param_name sp_opt_inout field_type
+          {
+            $1->mode= $2;
+            if (unlikely(Lex->sp_param_fill_definition($$= $1, $3)))
+              MYSQL_YYABORT;
+          }
+        | sp_param_name sp_opt_inout ROW_SYM row_type_body
+          {
+            $1->mode= $2;
+            if (unlikely(Lex->sphead->spvar_fill_row(thd, $$= $1, $4)))
+              MYSQL_YYABORT;
+          }
+        | sp_param_name_and_type_anchored
+        ;
+
 sp_param_name_and_type_anchored:
-          sp_param_name sp_decl_ident '.' ident PERCENT_ORACLE_SYM TYPE_SYM
+          sp_param_name sp_opt_inout sp_decl_ident '.' ident PERCENT_ORACLE_SYM TYPE_SYM
           {
-            if (unlikely(Lex->sphead->spvar_fill_type_reference(thd, $$= $1, $2, $4)))
+            $1->mode= $2;
+            if (unlikely(Lex->sphead->spvar_fill_type_reference(thd, $$= $1, $3, $5)))
               MYSQL_YYABORT;
           }
-        | sp_param_name sp_decl_ident '.' ident '.' ident PERCENT_ORACLE_SYM TYPE_SYM
+        | sp_param_name sp_opt_inout sp_decl_ident '.' ident '.' ident PERCENT_ORACLE_SYM TYPE_SYM
           {
-            if (unlikely(Lex->sphead->spvar_fill_type_reference(thd, $$= $1, $2, $4, $6)))
+            $1->mode= $2;
+            if (unlikely(Lex->sphead->spvar_fill_type_reference(thd, $$= $1, $3, $5, $7)))
               MYSQL_YYABORT;
           }
-        | sp_param_name sp_decl_ident PERCENT_ORACLE_SYM ROWTYPE_ORACLE_SYM
+        | sp_param_name sp_opt_inout sp_decl_ident PERCENT_ORACLE_SYM ROWTYPE_ORACLE_SYM
           {
-            if (unlikely(Lex->sphead->spvar_fill_table_rowtype_reference(thd, $$= $1, $2)))
+            $1->mode= $2;
+            if (unlikely(Lex->sphead->spvar_fill_table_rowtype_reference(thd, $$= $1, $3)))
               MYSQL_YYABORT;
           }
-        | sp_param_name sp_decl_ident '.' ident PERCENT_ORACLE_SYM ROWTYPE_ORACLE_SYM
+        | sp_param_name sp_opt_inout sp_decl_ident '.' ident PERCENT_ORACLE_SYM ROWTYPE_ORACLE_SYM
           {
-            if (unlikely(Lex->sphead->spvar_fill_table_rowtype_reference(thd, $$= $1, $2, $4)))
+            $1->mode= $2;
+            if (unlikely(Lex->sphead->spvar_fill_table_rowtype_reference(thd, $$= $1, $3, $5)))
               MYSQL_YYABORT;
           }
         ;