MDEV-10411 Providing compatibility for basic PL/SQL constructs

Part 17: RETURN in stored procedures

mysql-test/suite/compat/oracle/r/sp-code.result

@@ -415,8 +415,8 @@ END;
 SHOW FUNCTION CODE f1;
 Pos	Instruction
 0	set i@0 0
-1	set i@0 (i@0 + 1)
-2	jump_if_not 1(1) (i@0 >= 5)
+1	set i@0 i@0 + 1
+2	jump_if_not 1(1) i@0 >= 5
 3	jump 4
 4	freturn 3 i@0
 SELECT f1() FROM DUAL;
@@ -437,8 +437,8 @@ END;
 SHOW FUNCTION CODE f1;
 Pos	Instruction
 0	set i@0 0
-1	set i@0 (i@0 + 1)
-2	jump_if_not 1(0) (i@0 >= 5)
+1	set i@0 i@0 + 1
+2	jump_if_not 1(0) i@0 >= 5
 3	jump 4
 4	freturn 3 i@0
 SELECT f1() FROM DUAL;
@@ -466,8 +466,8 @@ SHOW FUNCTION CODE f1;
 Pos	Instruction
 0	set i@0 0
 1	jump 5
-2	set i@0 (i@0 + 1)
-3	jump_if_not 8(8) (i@0 >= 5)
+2	set i@0 i@0 + 1
+3	jump_if_not 8(8) i@0 >= 5
 4	jump 10
 5	hpush_jump 2 1 EXIT
 6	set i@0 1000
@@ -506,15 +506,15 @@ SHOW PROCEDURE CODE p1;
 Pos	Instruction
 0	set i@1 0
 1	jump 14
-2	set i@1 (i@1 + 1)
-3	jump_if_not 8(8) (i@1 >= 5)
+2	set i@1 i@1 + 1
+3	jump_if_not 8(8) i@1 >= 5
 4	jump 10
 5	hpush_jump 2 2 EXIT
 6	set a@0 1000
 7	hreturn 0 8
 8	hpop 1
 9	jump 5
-10	set i@1 (i@1 + 100)
+10	set i@1 i@1 + 100
 11	jump 12
 12	set a@0 i@1
 13	jump 17
@@ -528,3 +528,35 @@ SELECT @v;
 @v
 105
 DROP PROCEDURE p1;
+# Testing RETURN in procedures
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+IF a < 10 THEN
+BEGIN
+a:= a + 1;
+RETURN;
+END;
+END IF;
+a:= 200;
+EXCEPTION
+WHEN OTHERS THEN
+BEGIN
+a:= 100;
+RETURN;
+END;
+END;
+/
+SHOW PROCEDURE CODE p1;
+Pos	Instruction
+0	jump 6
+1	jump_if_not 4(4) a@0 < 10
+2	set a@0 a@0 + 1
+3	preturn
+4	set a@0 200
+5	jump 9
+6	hpush_jump 1 1 EXIT
+7	set a@0 100
+8	preturn
+9	hpop 1
+DROP PROCEDURE p1;

mysql-test/suite/compat/oracle/r/sp.result

@@ -677,3 +677,62 @@ f1()
 1
 DROP FUNCTION f1;
 DROP TABLE t1;
+# Testing RETURN in procedures
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+RETURN 10;
+END;
+/
+ERROR 42000: RETURN is only allowed in a FUNCTION
+CREATE FUNCTION f1 (a INT) RETURN INT
+AS
+BEGIN
+RETURN;
+END;
+/
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ';
+END' at line 4
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+IF a < 10 THEN
+BEGIN
+a:= a - 1;
+RETURN;
+END;
+END IF;
+a:= a + 1;
+EXCEPTION
+WHEN OTHERS THEN RETURN;
+END;
+/
+SET @v=10;
+CALL p1(@v);
+SELECT @v;
+@v
+11
+SET @v=9;
+CALL p1(@v);
+SELECT @v;
+@v
+8
+DROP PROCEDURE p1;
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+DROP TABLE t1_non_existent;
+EXCEPTION
+WHEN OTHERS THEN
+BEGIN
+a:= 100;
+RETURN;
+END;
+END;
+/
+SET @v=10;
+CALL p1(@v);
+SELECT @v;
+@v
+100
+DROP PROCEDURE p1;

mysql-test/suite/compat/oracle/t/sp-code.test

@@ -416,3 +416,28 @@ set @v= 10;
 CALL p1(@v);
 SELECT @v;
 DROP PROCEDURE p1;
+
+
+--echo # Testing RETURN in procedures
+DELIMITER /;
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+  IF a < 10 THEN
+    BEGIN
+      a:= a + 1;
+      RETURN;
+    END;
+  END IF;
+  a:= 200;
+EXCEPTION
+  WHEN OTHERS THEN
+  BEGIN
+    a:= 100;
+    RETURN;
+  END;
+END;
+/
+DELIMITER ;/
+SHOW PROCEDURE CODE p1;
+DROP PROCEDURE p1;

mysql-test/suite/compat/oracle/t/sp.test

@@ -735,3 +735,69 @@ DELIMITER ;/
 SELECT f1() FROM DUAL;
 DROP FUNCTION f1;
 DROP TABLE t1;
+
+
+--echo # Testing RETURN in procedures
+
+DELIMITER /;
+--error ER_SP_BADRETURN
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+  RETURN 10;
+END;
+/
+DELIMITER ;/
+
+DELIMITER /;
+--error ER_PARSE_ERROR
+CREATE FUNCTION f1 (a INT) RETURN INT
+AS
+BEGIN
+  RETURN;
+END;
+/
+DELIMITER ;/
+
+DELIMITER /;
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+  IF a < 10 THEN
+  BEGIN
+    a:= a - 1;
+    RETURN;
+  END;
+  END IF;
+  a:= a + 1;
+EXCEPTION
+  WHEN OTHERS THEN RETURN;
+END;
+/
+DELIMITER ;/
+SET @v=10;
+CALL p1(@v);
+SELECT @v;
+SET @v=9;
+CALL p1(@v);
+SELECT @v;
+DROP PROCEDURE p1;
+
+DELIMITER /;
+CREATE PROCEDURE p1 (a IN OUT INT)
+AS
+BEGIN
+  DROP TABLE t1_non_existent;
+EXCEPTION
+  WHEN OTHERS THEN
+  BEGIN
+    a:= 100;
+    RETURN;
+  END;
+END;
+/
+DELIMITER ;/
+SET @v=10;
+CALL p1(@v);
+SELECT @v;
+DROP PROCEDURE p1;

sql/sp_head.h

@@ -1030,6 +1030,41 @@ private:
 }; // class sp_instr_jump_if_not : public sp_instr_jump
 
 
+class sp_instr_preturn : public sp_instr
+{
+  sp_instr_preturn(const sp_instr_preturn &);	/**< Prevent use of these */
+  void operator=(sp_instr_preturn &);
+
+public:
+
+  sp_instr_preturn(uint ip, sp_pcontext *ctx)
+    : sp_instr(ip, ctx)
+  {}
+
+  virtual ~sp_instr_preturn()
+  {}
+
+  virtual int execute(THD *thd, uint *nextp)
+  {
+    DBUG_ENTER("sp_instr_preturn::execute");
+    *nextp= UINT_MAX;
+    DBUG_RETURN(0);
+  }
+
+  virtual void print(String *str)
+  {
+    str->append(STRING_WITH_LEN("preturn"));
+  }
+
+  virtual uint opt_mark(sp_head *sp, List<sp_instr> *leads)
+  {
+    marked= 1;
+    return UINT_MAX;
+  }
+
+}; // class sp_instr_preturn : public sp_instr
+
+
 class sp_instr_freturn : public sp_instr
 {
   sp_instr_freturn(const sp_instr_freturn &);	/**< Prevent use of these */

sql/sql_yacc_ora.yy

@@ -2963,6 +2963,22 @@ sp_proc_stmt_return:
             if (sp->restore_lex(thd))
               MYSQL_YYABORT;
           }
+        | RETURN_SYM
+          {
+            LEX *lex= Lex;
+            sp_head *sp= lex->sphead;
+
+            if (sp->m_type != TYPE_ENUM_PROCEDURE)
+            {
+              thd->parse_error();
+              MYSQL_YYABORT;
+            }
+            sp_instr_preturn *i;
+            i= new (thd->mem_root)
+                 sp_instr_preturn(sp->instructions(), lex->spcont);
+            if (i == NULL || sp->add_instr(i))
+              MYSQL_YYABORT;
+          }
         ;
 
 opt_sp_proc_stmt_exit_when_clause: