MDEV-5816: Stored programs: validation of stored program statements

This is the prerequisite patch to change a signature of the virtual
method opt_move() in the base class sp_instr and its derived classes.
The parameterized type of the instuctions list returned in the second
argument is changed from sp_instr to sp_instr_opt_meta since only
jump instructions are placed in this list on returning from
the method call.

3 files changed, 14 insertions, 12 deletions

diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index aec8983f76f..ffcedaea315 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -3146,7 +3146,7 @@ bool sp_head::replace_instr_to_nop(THD *thd, uint ip)
 
 void sp_head::optimize()
 {
-  List<sp_instr> bp;
+  List<sp_instr_opt_meta> bp;
   sp_instr *i;
   uint src, dst;
 
@@ -3168,14 +3168,13 @@ void sp_head::optimize()
       if (src != dst)
       {
         /* Move the instruction and update prev. jumps */
-        sp_instr *ibp;
-        List_iterator_fast<sp_instr> li(bp);
+        sp_instr_opt_meta *ibp;
+        List_iterator_fast<sp_instr_opt_meta> li(bp);
 
         set_dynamic(&m_instr, (uchar*)&i, dst);
         while ((ibp= li++))
         {
-          sp_instr_opt_meta *im= static_cast<sp_instr_opt_meta *>(ibp);
-          im->set_destination(src, dst);
+          ibp->set_destination(src, dst);
         }
       }
       i->opt_move(dst, &bp);
diff --git a/sql/sp_instr.cc b/sql/sp_instr.cc
index d75cd11187a..c51c7f9d3db 100644
--- a/sql/sp_instr.cc
+++ b/sql/sp_instr.cc
@@ -817,7 +817,7 @@ sp_instr_jump::opt_shortcut_jump(sp_head *sp, sp_instr *start)
 }
 
 void
-sp_instr_jump::opt_move(uint dst, List<sp_instr> *bp)
+sp_instr_jump::opt_move(uint dst, List<sp_instr_opt_meta> *bp)
 {
   if (m_dest > m_ip)
     bp->push_back(this);      // Forward
@@ -905,7 +905,7 @@ sp_instr_jump_if_not::opt_mark(sp_head *sp, List<sp_instr> *leads)
 }
 
 void
-sp_instr_jump_if_not::opt_move(uint dst, List<sp_instr> *bp)
+sp_instr_jump_if_not::opt_move(uint dst, List<sp_instr_opt_meta> *bp)
 {
   /*
     cont. destinations may point backwards after shortcutting jumps
@@ -1655,7 +1655,7 @@ sp_instr_set_case_expr::opt_mark(sp_head *sp, List<sp_instr> *leads)
 }
 
 void
-sp_instr_set_case_expr::opt_move(uint dst, List<sp_instr> *bp)
+sp_instr_set_case_expr::opt_move(uint dst, List<sp_instr_opt_meta> *bp)
 {
   if (m_cont_dest > m_ip)
     bp->push_back(this);        // Forward
diff --git a/sql/sp_instr.h b/sql/sp_instr.h
index 8cf752b80f9..423d6f77153 100644
--- a/sql/sp_instr.h
+++ b/sql/sp_instr.h
@@ -58,6 +58,9 @@ public:
 // "Instructions"...
 //
 
+// Forward declaration for use in the method sp_instr::opt_move().
+class sp_instr_opt_meta;
+
 class sp_instr :public Query_arena, public Sql_alloc
 {
   sp_instr(const sp_instr &);   /**< Prevent use of these */
@@ -160,7 +163,7 @@ public:
     must also take care of their destination pointers. Forward jumps get
     pushed to the backpatch list 'ibp'.
   */
-  virtual void opt_move(uint dst, List<sp_instr> *ibp)
+  virtual void opt_move(uint dst, List<sp_instr_opt_meta> *ibp)
   {
     m_ip= dst;
   }
@@ -493,7 +496,7 @@ public:
 
   uint opt_shortcut_jump(sp_head *sp, sp_instr *start) override;
 
-  void opt_move(uint dst, List<sp_instr> *ibp) override;
+  void opt_move(uint dst, List<sp_instr_opt_meta> *ibp) override;
 
   void backpatch(uint dest, sp_pcontext *dst_ctx) override
   {
@@ -548,7 +551,7 @@ public:
     return m_ip;
   }
 
-  void opt_move(uint dst, List<sp_instr> *ibp) override;
+  void opt_move(uint dst, List<sp_instr_opt_meta> *ibp) override;
 
   void set_destination(uint old_dest, uint new_dest) override
   {
@@ -1022,7 +1025,7 @@ public:
 
   uint opt_mark(sp_head *sp, List<sp_instr> *leads) override;
 
-  void opt_move(uint dst, List<sp_instr> *ibp) override;
+  void opt_move(uint dst, List<sp_instr_opt_meta> *ibp) override;
 
   void set_destination(uint old_dest, uint new_dest) override
   {