MDEV-11952 Oracle-style packages: stage#5

- CREATE PACKAGE [BODY] statements are now
  entirely written to mysql.proc with type='PACKAGE' and type='PACKAGE BODY'.
- CREATE PACKAGE BODY now supports IF NOT EXISTS
- DROP PACKAGE BODY now supports IF EXISTS
- CREATE OR REPLACE PACKAGE [BODY] is now supported
- CREATE PACKAGE [BODY] now support the DEFINER clause:

    CREATE DEFINER user@host PACKAGE pkg ... END;
    CREATE DEFINER user@host PACKAGE BODY pkg ... END;

- CREATE PACKAGE [BODY] now supports SQL SECURITY and COMMENT clauses, e.g.:

    CREATE PACKAGE p1 SQL SECURITY INVOKER COMMENT "comment" AS ... END;

- Package routines are now created from the package CREATE PACKAGE BODY
  statement and don't produce individual records in mysql.proc.

- CREATE PACKAGE BODY now supports package-wide variables.
  Package variables can be read and set inside package routines.
  Package variables are stored in a separate sp_rcontext,
  which is cached in THD on the first packate routine call.

- CREATE PACKAGE BODY now supports the initialization section.

- All public routines (i.e. declared in CREATE PACKAGE)
  must have implementations in CREATE PACKAGE BODY

- Only public package routines are available outside of the package

- {CREATE|DROP} PACKAGE [BODY] now respects CREATE ROUTINE and ALTER ROUTINE
  privileges

- "GRANT EXECUTE ON PACKAGE BODY pkg" is now supported

- SHOW CREATE PACKAGE [BODY] is now supported

- SHOW PACKAGE [BODY] STATUS is now supported

- CREATE and DROP for PACKAGE [BODY] now works for non-current databases

- mysqldump now supports packages

- "SHOW {PROCEDURE|FUNCTION) CODE pkg.routine" now works for package routines

- "SHOW PACKAGE BODY CODE pkg" now works (the package initialization section)

- A new package body level MDL was added

- Recursive calls for package procedures are now possible

- Routine forward declarations in CREATE PACKATE BODY are now supported.

- Package body variables now work as SP OUT parameters

- Package body variables now work as SELECT INTO targets

- Package body variables now support ROW, %ROWTYPE, %TYPE

sql/sql_class.h

@@ -3166,6 +3166,8 @@ public:
   sp_rcontext *spcont;		// SP runtime context
   sp_cache   *sp_proc_cache;
   sp_cache   *sp_func_cache;
+  sp_cache   *sp_package_spec_cache;
+  sp_cache   *sp_package_body_cache;
 
   /** number of name_const() substitutions, see sp_head.cc:subst_spvars() */
   uint       query_name_consts;
@@ -5902,6 +5904,7 @@ public:
 };
 
 class my_var_sp: public my_var {
+  const Sp_rcontext_handler *m_rcontext_handler;
   const Type_handler *m_type_handler;
 public:
   uint offset;
@@ -5910,13 +5913,17 @@ public:
     runtime context is used for variable handling.
   */
   sp_head *sp;
-  my_var_sp(const LEX_CSTRING *j, uint o, const Type_handler *type_handler,
+  my_var_sp(const Sp_rcontext_handler *rcontext_handler,
+            const LEX_CSTRING *j, uint o, const Type_handler *type_handler,
             sp_head *s)
-    : my_var(j, LOCAL_VAR), m_type_handler(type_handler), offset(o), sp(s) { }
+    : my_var(j, LOCAL_VAR),
+      m_rcontext_handler(rcontext_handler),
+      m_type_handler(type_handler), offset(o), sp(s) { }
   ~my_var_sp() { }
   bool set(THD *thd, Item *val);
   my_var_sp *get_my_var_sp() { return this; }
   const Type_handler *type_handler() const { return m_type_handler; }
+  sp_rcontext *get_rcontext(sp_rcontext *local_ctx) const;
 };
 
 /*
@@ -5927,9 +5934,11 @@ class my_var_sp_row_field: public my_var_sp
 {
   uint m_field_offset;
 public:
-  my_var_sp_row_field(const LEX_CSTRING *varname, const LEX_CSTRING *fieldname,
+  my_var_sp_row_field(const Sp_rcontext_handler *rcontext_handler,
+                      const LEX_CSTRING *varname, const LEX_CSTRING *fieldname,
                       uint var_idx, uint field_idx, sp_head *s)
-   :my_var_sp(varname, var_idx, &type_handler_double/*Not really used*/, s),
+   :my_var_sp(rcontext_handler, varname, var_idx,
+              &type_handler_double/*Not really used*/, s),
     m_field_offset(field_idx)
   { }
   bool set(THD *thd, Item *val);
@@ -6304,6 +6313,9 @@ public:
   Database_qualified_name(const LEX_CSTRING *db, const LEX_CSTRING *name)
    :m_db(*db), m_name(*name)
   { }
+  Database_qualified_name(const LEX_CSTRING &db, const LEX_CSTRING &name)
+   :m_db(db), m_name(name)
+  { }
   Database_qualified_name(const char *db, size_t db_length,
                           const char *name, size_t name_length)
   {
@@ -6353,6 +6365,34 @@ public:
     DBUG_SLOW_ASSERT(ok_for_lower_case_names(m_db.str));
     return false;
   }
+
+  bool make_package_routine_name(MEM_ROOT *mem_root,
+                                 const LEX_CSTRING &package,
+                                 const LEX_CSTRING &routine)
+  {
+    char *tmp;
+    size_t length= package.length + 1 + routine.length + 1;
+    if (!(tmp= (char *) alloc_root(mem_root, length)))
+      return true;
+    m_name.length= my_snprintf(tmp, length, "%.*s.%.*s",
+                               (int) package.length, package.str,
+                               (int) routine.length, routine.str);
+    m_name.str= tmp;
+    return false;
+  }
+
+  bool make_package_routine_name(MEM_ROOT *mem_root,
+                                 const LEX_CSTRING &db,
+                                 const LEX_CSTRING &package,
+                                 const LEX_CSTRING &routine)
+  {
+    if (make_package_routine_name(mem_root, package, routine))
+      return true;
+    if (!(m_db.str= strmake_root(mem_root, db.str, db.length)))
+      return true;
+    m_db.length= db.length;
+    return false;
+  }
 };