MDEV-10411 Providing compatibility for basic PL/SQL constructs

Fixed that the ITERATE statement inside a FOR LOOP statement did not
increment the index variable before jumping to the beginning
of the loop, which caused the loop to repeat endlessly.

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

@@ -677,3 +677,123 @@ SELECT f1(2, 3, 2, 3) FROM DUAL;
 f1(2, 3, 2, 3)
 2004
 DROP FUNCTION f1;
+# Testing labeled ITERATE in a labeled FOR LOOP
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+total INT:= 0;
+BEGIN
+<<li>>
+FOR i IN 1 .. a
+LOOP
+total:= total + 1000;
+IF i = 5 THEN
+ITERATE li;
+END IF;
+total:= total + 1;
+END LOOP;
+RETURN total;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set total@1 0
+1	set i@2 1
+2	set [upper_bound]@3 a@0
+3	jump_if_not 11(11) (i@2 <= [upper_bound]@3)
+4	set total@1 (total@1 + 1000)
+5	jump_if_not 8(8) (i@2 = 5)
+6	set i@2 (i@2 + 1)
+7	jump 3
+8	set total@1 (total@1 + 1)
+9	set i@2 (i@2 + 1)
+10	jump 3
+11	freturn 3 total@1
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+f1(3)	f1(4)	f1(5)	f1(6)
+3003	4004	5004	6005
+DROP FUNCTION f1;
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+total INT:= 0;
+BEGIN
+<<li>>
+FOR i IN 1 .. a
+LOOP
+FOR j IN 1 .. 2
+LOOP
+total:= total + 1000;
+IF i = 5 THEN
+ITERATE li;
+END IF;
+total:= total + 1;
+END LOOP;
+END LOOP;
+RETURN total;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set total@1 0
+1	set i@2 1
+2	set [upper_bound]@3 a@0
+3	jump_if_not 16(16) (i@2 <= [upper_bound]@3)
+4	set j@4 1
+5	set [upper_bound]@5 2
+6	jump_if_not 14(14) (j@4 <= [upper_bound]@5)
+7	set total@1 (total@1 + 1000)
+8	jump_if_not 11(11) (i@2 = 5)
+9	set i@2 (i@2 + 1)
+10	jump 3
+11	set total@1 (total@1 + 1)
+12	set j@4 (j@4 + 1)
+13	jump 6
+14	set i@2 (i@2 + 1)
+15	jump 3
+16	freturn 3 total@1
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+f1(3)	f1(4)	f1(5)	f1(6)
+6006	8008	9008	11010
+DROP FUNCTION f1;
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+total INT:= 0;
+BEGIN
+<<lj>>
+FOR j IN 1 .. 2
+LOOP
+<<li>>
+FOR i IN 1 .. a
+LOOP
+total:= total + 1000;
+IF i = 5 THEN
+ITERATE li;
+END IF;
+total:= total + 1;
+END LOOP;
+END LOOP;
+RETURN total;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set total@1 0
+1	set j@2 1
+2	set [upper_bound]@3 2
+3	jump_if_not 16(16) (j@2 <= [upper_bound]@3)
+4	set i@4 1
+5	set [upper_bound]@5 a@0
+6	jump_if_not 14(14) (i@4 <= [upper_bound]@5)
+7	set total@1 (total@1 + 1000)
+8	jump_if_not 11(11) (i@4 = 5)
+9	set i@4 (i@4 + 1)
+10	jump 6
+11	set total@1 (total@1 + 1)
+12	set i@4 (i@4 + 1)
+13	jump 6
+14	set j@2 (j@2 + 1)
+15	jump 3
+16	freturn 3 total@1
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+f1(3)	f1(4)	f1(5)	f1(6)
+6006	8008	10008	12010
+DROP FUNCTION f1;

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

@@ -899,3 +899,50 @@ SELECT f1(2, 3, 2, 3) FROM DUAL;
 f1(2, 3, 2, 3)
 2004
 DROP FUNCTION f1;
+# Testing labeled ITERATE in a labeled FOR LOOP statement
+CREATE FUNCTION f1 (a INT, b INT, blim INT) RETURN INT
+AS
+total INT := 0;
+BEGIN
+<<la>>
+FOR ia IN 1 .. a
+LOOP
+total:= total + 1000;
+DECLARE
+ib INT:= 1;
+BEGIN
+WHILE ib <= b
+LOOP
+IF ib > blim THEN
+ITERATE la;
+END IF;
+ib:= ib + 1;
+total:= total + 1;
+END LOOP;
+END;
+END LOOP la;
+RETURN total;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set total@3 0
+1	set ia@4 1
+2	set [upper_bound]@5 a@0
+3	jump_if_not 15(15) (ia@4 <= [upper_bound]@5)
+4	set total@3 (total@3 + 1000)
+5	set ib@6 1
+6	jump_if_not 13(13) (ib@6 <= b@1)
+7	jump_if_not 10(10) (ib@6 > blim@2)
+8	set ia@4 (ia@4 + 1)
+9	jump 3
+10	set ib@6 (ib@6 + 1)
+11	set total@3 (total@3 + 1)
+12	jump 6
+13	set ia@4 (ia@4 + 1)
+14	jump 3
+15	freturn 3 total@3
+SELECT f1(3,3,0), f1(3,3,1), f1(3,3,2), f1(3,3,3), f1(3,3,4) FROM DUAL;
+f1(3,3,0)	f1(3,3,1)	f1(3,3,2)	f1(3,3,3)	f1(3,3,4)
+3000	3003	3006	3009	3009
+DROP FUNCTION f1;

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

@@ -486,6 +486,7 @@ SELECT f1(3, 100) FROM DUAL;
 SELECT f1(3, 2) FROM DUAL;
 DROP FUNCTION f1;
 
+
 --echo # Testing labeled FOR LOOP statement
 
 DELIMITER /;
@@ -514,3 +515,81 @@ SELECT f1(2, 1, 2, 2) FROM DUAL;
 SELECT f1(2, 2, 2, 2) FROM DUAL;
 SELECT f1(2, 3, 2, 3) FROM DUAL;
 DROP FUNCTION f1;
+
+
+--echo # Testing labeled ITERATE in a labeled FOR LOOP
+
+DELIMITER /;
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+  total INT:= 0;
+BEGIN
+  <<li>>
+  FOR i IN 1 .. a
+  LOOP
+    total:= total + 1000;
+    IF i = 5 THEN
+      ITERATE li;
+    END IF;
+    total:= total + 1;
+  END LOOP;
+  RETURN total;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+DROP FUNCTION f1;
+
+
+DELIMITER /;
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+  total INT:= 0;
+BEGIN
+  <<li>>
+  FOR i IN 1 .. a
+  LOOP
+    FOR j IN 1 .. 2
+    LOOP
+      total:= total + 1000;
+      IF i = 5 THEN
+        ITERATE li;
+      END IF;
+      total:= total + 1;
+    END LOOP;
+  END LOOP;
+  RETURN total;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+DROP FUNCTION f1;
+
+
+DELIMITER /;
+CREATE FUNCTION f1(a INT) RETURN INT
+AS
+  total INT:= 0;
+BEGIN
+  <<lj>>
+  FOR j IN 1 .. 2
+  LOOP
+    <<li>>
+    FOR i IN 1 .. a
+    LOOP
+      total:= total + 1000;
+      IF i = 5 THEN
+        ITERATE li;
+      END IF;
+      total:= total + 1;
+    END LOOP;
+  END LOOP;
+  RETURN total;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1(3), f1(4), f1(5), f1(6) FROM DUAL;
+DROP FUNCTION f1;

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

@@ -963,3 +963,36 @@ SELECT f1(2, 1, 2, 2) FROM DUAL;
 SELECT f1(2, 2, 2, 2) FROM DUAL;
 SELECT f1(2, 3, 2, 3) FROM DUAL;
 DROP FUNCTION f1;
+
+
+--echo # Testing labeled ITERATE in a labeled FOR LOOP statement
+
+DELIMITER /;
+CREATE FUNCTION f1 (a INT, b INT, blim INT) RETURN INT
+AS
+  total INT := 0;
+BEGIN
+  <<la>>
+  FOR ia IN 1 .. a
+  LOOP
+    total:= total + 1000;
+    DECLARE
+      ib INT:= 1;
+    BEGIN
+      WHILE ib <= b
+      LOOP
+        IF ib > blim THEN
+          ITERATE la;
+        END IF;
+        ib:= ib + 1;
+        total:= total + 1;
+      END LOOP;
+    END;
+  END LOOP la;
+  RETURN total;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1(3,3,0), f1(3,3,1), f1(3,3,2), f1(3,3,3), f1(3,3,4) FROM DUAL;
+DROP FUNCTION f1;

sql/sp_pcontext.h

@@ -268,6 +268,12 @@ class sp_pcontext : public Sql_alloc
     HANDLER_SCOPE
   };
 
+  class Lex_for_loop: public Lex_for_loop_st
+  {
+  public:
+    Lex_for_loop() { init(); }
+  };
+
 public:
   sp_pcontext();
   ~sp_pcontext();
@@ -513,6 +519,15 @@ class sp_pcontext : public Sql_alloc
   uint current_cursor_count() const
   { return m_cursor_offset + m_cursors.elements(); }
 
+  void set_for_loop(const Lex_for_loop_st &for_loop)
+  {
+    m_for_loop.init(for_loop);
+  }
+  const Lex_for_loop_st &for_loop()
+  {
+    return m_for_loop;
+  }
+
 private:
   /// Constructor for a tree node.
   /// @param prev the parent parsing context
@@ -583,6 +598,9 @@ class sp_pcontext : public Sql_alloc
 
   /// Scope of this parsing context.
   enum_scope m_scope;
+
+  /// FOR LOOP characteristics
+  Lex_for_loop m_for_loop;
 }; // class sp_pcontext : public Sql_alloc
 
 

sql/sql_lex.cc

@@ -5317,6 +5317,7 @@ bool LEX::sp_for_loop_condition(THD *thd, const Lex_for_loop_st &loop)
 */
 bool LEX::sp_for_loop_index_and_bounds(THD *thd, const Lex_for_loop_st &loop)
 {
+  spcont->set_for_loop(loop);
   sphead->reset_lex(thd);
   if (thd->lex->sp_for_loop_condition(thd, loop))
     return true;
@@ -5674,6 +5675,15 @@ bool LEX::sp_iterate_statement(THD *thd, const LEX_STRING label_name)
     my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "ITERATE", label_name.str);
     return true;
   }
+  if (lab->ctx->for_loop().m_index)
+  {
+    // We're in a FOR loop, increment the index variable before backward jump
+    sphead->reset_lex(thd);
+    DBUG_ASSERT(this != thd->lex);
+    if (thd->lex->sp_for_loop_increment(thd, lab->ctx->for_loop()) ||
+        thd->lex->sphead->restore_lex(thd))
+      return true;
+  }
   return sp_change_context(thd, lab->ctx, false) ||
          sphead->add_instr_jump(thd, spcont, lab->ip); /* Jump back */
 }

sql/structs.h

@@ -675,6 +675,16 @@ struct Lex_for_loop_st
   class sp_variable *m_index;
   class sp_variable *m_upper_bound;
   int m_direction;
+  void init()
+  {
+    m_index= 0;
+    m_upper_bound= 0;
+    m_direction= 0;
+  }
+  void init(const Lex_for_loop_st &other)
+  {
+    *this= other;
+  }
 };