MDEV-10411 Providing compatibility for basic PL/SQL constructs

Moving the code from *.yy to methods:
LEX::sp_change_context()
LEX::sp_leave_statement()
LEX::sp_iterate_statement()
to reuse the same code between LEAVE and ITERATE statements.
EXIT statement will also reuse the same code.

sql/sp_head.cc

@@ -2571,12 +2571,12 @@ bool sp_head::add_instr_jump(THD *thd, sp_pcontext *spcont, uint dest)
 
 
 bool sp_head::add_instr_jump_forward_with_backpatch(THD *thd,
-                                                    sp_pcontext *spcont)
+                                                    sp_pcontext *spcont,
+                                                    sp_label *lab)
 {
   sp_instr_jump  *i= new (thd->mem_root) sp_instr_jump(instructions(), spcont);
   if (i == NULL || add_instr(i))
     return true;
-  sp_label *lab= spcont->last_label();
   push_backpatch(thd, i, lab);
   return false;
 }

sql/sp_head.h

@@ -344,7 +344,15 @@ class sp_head :private Query_arena,
   add_instr_jump(THD *thd, sp_pcontext *spcont, uint dest);
 
   bool
-  add_instr_jump_forward_with_backpatch(THD *thd, sp_pcontext *spcont);
+  add_instr_jump_forward_with_backpatch(THD *thd, sp_pcontext *spcont,
+                                        sp_label *lab);
+  bool
+  add_instr_jump_forward_with_backpatch(THD *thd, sp_pcontext *spcont)
+  {
+    return add_instr_jump_forward_with_backpatch(thd, spcont,
+                                                 spcont->last_label());
+  }
+
 
   /**
     Returns true if any substatement in the routine directly

sql/sql_lex.cc

@@ -5449,6 +5449,63 @@ LEX::sp_block_with_exceptions_finalize_exceptions(THD *thd,
   return sphead->add_instr_jump(thd, spcont, executable_section_ip);
 }
 
+
+bool LEX::sp_change_context(THD *thd, const sp_pcontext *ctx, bool exclusive)
+{
+  uint n;
+  uint ip= sphead->instructions();
+  if ((n= spcont->diff_handlers(ctx, exclusive)))
+  {
+    sp_instr_hpop *hpop= new (thd->mem_root) sp_instr_hpop(ip++, spcont, n);
+    if (hpop == NULL || sphead->add_instr(hpop))
+      return true;
+  }
+  if ((n= spcont->diff_cursors(ctx, exclusive)))
+  {
+    sp_instr_cpop *cpop= new (thd->mem_root) sp_instr_cpop(ip++, spcont, n);
+    if (cpop == NULL || sphead->add_instr(cpop))
+      return true;
+  }
+  return false;
+}
+
+
+bool LEX::sp_leave_statement(THD *thd, const LEX_STRING label_name)
+{
+  sp_label *lab= spcont->find_label(label_name);
+  if (!lab)
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "LEAVE", label_name.str);
+    return true;
+  }
+
+  /*
+    When jumping to a BEGIN-END block end, the target jump
+    points to the block hpop/cpop cleanup instructions,
+    so we should exclude the block context here.
+    When jumping to something else (i.e., SP_LAB_ITER),
+    there are no hpop/cpop at the jump destination,
+    so we should include the block context here for cleanup.
+  */
+  bool exclusive= (lab->type == sp_label::BEGIN);
+  return sp_change_context(thd, lab->ctx, exclusive) ||
+         sphead->add_instr_jump_forward_with_backpatch(thd, spcont, lab);
+}
+
+
+bool LEX::sp_iterate_statement(THD *thd, const LEX_STRING label_name)
+{
+  sp_label *lab= spcont->find_label(label_name);
+  if (!lab || lab->type != sp_label::ITERATION)
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "ITERATE", label_name.str);
+    return true;
+  }
+  return sp_change_context(thd, lab->ctx, false) ||
+         sphead->add_instr_jump(thd, spcont, lab->ip); /* Jump back */
+}
+
+
 #ifdef MYSQL_SERVER
 uint binlog_unsafe_map[256];
 

sql/sql_lex.h

@@ -3151,6 +3151,10 @@ struct LEX: public Query_tables_list
   bool sp_block_with_exceptions_finalize_exceptions(THD *thd,
                                                   uint executable_section_ip,
                                                   uint exception_count);
+  bool sp_change_context(THD *thd, const sp_pcontext *ctx, bool exclusive);
+  bool sp_leave_statement(THD *thd, const LEX_STRING label_name);
+  bool sp_iterate_statement(THD *thd, const LEX_STRING label_name);
+
   // Check if "KEY IF NOT EXISTS name" used outside of ALTER context
   bool check_add_key(DDL_options_st ddl)
   {

sql/sql_yacc.yy

@@ -3600,90 +3600,15 @@ sp_proc_stmt_return:
 sp_proc_stmt_leave:
           LEAVE_SYM label_ident
           {
-            LEX *lex= Lex;
-            sp_head *sp = lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            sp_label *lab= ctx->find_label($2);
-
-            if (! lab)
-              my_yyabort_error((ER_SP_LILABEL_MISMATCH, MYF(0), "LEAVE", $2.str));
-
-            sp_instr_jump *i;
-            uint ip= sp->instructions();
-            uint n;
-            /*
-              When jumping to a BEGIN-END block end, the target jump
-              points to the block hpop/cpop cleanup instructions,
-              so we should exclude the block context here.
-              When jumping to something else (i.e., SP_LAB_ITER),
-              there are no hpop/cpop at the jump destination,
-              so we should include the block context here for cleanup.
-            */
-            bool exclusive= (lab->type == sp_label::BEGIN);
-
-            n= ctx->diff_handlers(lab->ctx, exclusive);
-            if (n)
-            {
-              sp_instr_hpop *hpop= new (thd->mem_root)
-                sp_instr_hpop(ip++, ctx, n);
-              if (hpop == NULL)
-                MYSQL_YYABORT;
-              sp->add_instr(hpop);
-            }
-            n= ctx->diff_cursors(lab->ctx, exclusive);
-            if (n)
-            {
-              sp_instr_cpop *cpop= new (thd->mem_root)
-                sp_instr_cpop(ip++, ctx, n);
-              if (cpop == NULL)
+            if (Lex->sp_leave_statement(thd, $2))
               MYSQL_YYABORT;
-              sp->add_instr(cpop);
-            }
-            i= new (thd->mem_root) sp_instr_jump(ip, ctx);
-            if (i == NULL)
-              MYSQL_YYABORT;
-            sp->push_backpatch(thd, i, lab);  /* Jumping forward */
-            sp->add_instr(i);
           }
         ;
 
 sp_proc_stmt_iterate:
           ITERATE_SYM label_ident
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            sp_label *lab= ctx->find_label($2);
-
-            if (! lab || lab->type != sp_label::ITERATION)
-              my_yyabort_error((ER_SP_LILABEL_MISMATCH, MYF(0), "ITERATE", $2.str));
-
-            sp_instr_jump *i;
-            uint ip= sp->instructions();
-            uint n;
-
-            n= ctx->diff_handlers(lab->ctx, FALSE);  /* Inclusive the dest. */
-            if (n)
-            {
-              sp_instr_hpop *hpop= new (thd->mem_root)
-                sp_instr_hpop(ip++, ctx, n);
-              if (hpop == NULL ||
-                  sp->add_instr(hpop))
-                MYSQL_YYABORT;
-            }
-            n= ctx->diff_cursors(lab->ctx, FALSE);  /* Inclusive the dest. */
-            if (n)
-            {
-              sp_instr_cpop *cpop= new (thd->mem_root)
-                sp_instr_cpop(ip++, ctx, n);
-              if (cpop == NULL ||
-                  sp->add_instr(cpop))
-                MYSQL_YYABORT;
-            }
-            i= new (thd->mem_root)
-              sp_instr_jump(ip, ctx, lab->ip); /* Jump back */
-            if (i == NULL ||
-                sp->add_instr(i))
+            if (Lex->sp_iterate_statement(thd, $2))
               MYSQL_YYABORT;
           }
         ;

sql/sql_yacc_ora.yy

@@ -3007,90 +3007,15 @@ sp_proc_stmt_return:
 sp_proc_stmt_leave:
           LEAVE_SYM label_ident
           {
-            LEX *lex= Lex;
-            sp_head *sp = lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            sp_label *lab= ctx->find_label($2);
-
-            if (! lab)
-              my_yyabort_error((ER_SP_LILABEL_MISMATCH, MYF(0), "LEAVE", $2.str));
-
-            sp_instr_jump *i;
-            uint ip= sp->instructions();
-            uint n;
-            /*
-              When jumping to a BEGIN-END block end, the target jump
-              points to the block hpop/cpop cleanup instructions,
-              so we should exclude the block context here.
-              When jumping to something else (i.e., SP_LAB_ITER),
-              there are no hpop/cpop at the jump destination,
-              so we should include the block context here for cleanup.
-            */
-            bool exclusive= (lab->type == sp_label::BEGIN);
-
-            n= ctx->diff_handlers(lab->ctx, exclusive);
-            if (n)
-            {
-              sp_instr_hpop *hpop= new (thd->mem_root)
-                sp_instr_hpop(ip++, ctx, n);
-              if (hpop == NULL)
-                MYSQL_YYABORT;
-              sp->add_instr(hpop);
-            }
-            n= ctx->diff_cursors(lab->ctx, exclusive);
-            if (n)
-            {
-              sp_instr_cpop *cpop= new (thd->mem_root)
-                sp_instr_cpop(ip++, ctx, n);
-              if (cpop == NULL)
+            if (Lex->sp_leave_statement(thd, $2))
               MYSQL_YYABORT;
-              sp->add_instr(cpop);
-            }
-            i= new (thd->mem_root) sp_instr_jump(ip, ctx);
-            if (i == NULL)
-              MYSQL_YYABORT;
-            sp->push_backpatch(thd, i, lab);  /* Jumping forward */
-            sp->add_instr(i);
           }
         ;
 
 sp_proc_stmt_iterate:
           ITERATE_SYM label_ident
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            sp_label *lab= ctx->find_label($2);
-
-            if (! lab || lab->type != sp_label::ITERATION)
-              my_yyabort_error((ER_SP_LILABEL_MISMATCH, MYF(0), "ITERATE", $2.str));
-
-            sp_instr_jump *i;
-            uint ip= sp->instructions();
-            uint n;
-
-            n= ctx->diff_handlers(lab->ctx, FALSE);  /* Inclusive the dest. */
-            if (n)
-            {
-              sp_instr_hpop *hpop= new (thd->mem_root)
-                sp_instr_hpop(ip++, ctx, n);
-              if (hpop == NULL ||
-                  sp->add_instr(hpop))
-                MYSQL_YYABORT;
-            }
-            n= ctx->diff_cursors(lab->ctx, FALSE);  /* Inclusive the dest. */
-            if (n)
-            {
-              sp_instr_cpop *cpop= new (thd->mem_root)
-                sp_instr_cpop(ip++, ctx, n);
-              if (cpop == NULL ||
-                  sp->add_instr(cpop))
-                MYSQL_YYABORT;
-            }
-            i= new (thd->mem_root)
-              sp_instr_jump(ip, ctx, lab->ip); /* Jump back */
-            if (i == NULL ||
-                sp->add_instr(i))
+            if (Lex->sp_iterate_statement(thd, $2))
               MYSQL_YYABORT;
           }
         ;