WL#15426: Implement SHOW PARSE_TREE [3/3, enable]

SHOW PARSE_TREE <select_query> returns a single column row containing
the json string corresponding to the parse tree.  If input SQL has
syntax errors or any errors during contextualize() phase, it is
aborted with error.

When a new PT_* class is introduced, SHOW PARSE_TREE will show this
json node along with it's PT_* children, thanks to contextualize(). If
the class has members of type other than PT_* and if they are required
to re-generate the SQL clause, such information is displayed using
appropriate json fields using an overridden function
Parse_tree_node::add_json_info().

PT_subquery is generated using a separate child Parse_context. So the
corresponding json tree of the child Parse_context had to be plugged
in to the json tree of the parent Parse_context.

Only SELECT statement is supported. Also, 'expr' parser productions
are not exhaustively covered for node-specific json fields. Will
probably be done in future releases.

Enabled only in Debug build; new cmake flag introduced to enable in
non-debug build.

Change-Id: I19c0b496bfaf8b6cf7661c8874d8118921d58201

Author: Amit Khandekar

CMakeLists.txt

@@ -2118,6 +2118,17 @@ OPTION(WITH_HYPERGRAPH_OPTIMIZER
   ${WITH_HYPERGRAPH_OPTIMIZER_DEFAULT}
   )
 
+# Allow SHOW PARSE_TREE on debug build by default.
+IF(CMAKE_BUILD_TYPE_UPPER STREQUAL "DEBUG" OR WITH_DEBUG)
+  SET(WITH_SHOW_PARSE_TREE_DEFAULT ON)
+ELSE()
+  SET(WITH_SHOW_PARSE_TREE_DEFAULT OFF)
+ENDIF()
+OPTION(WITH_SHOW_PARSE_TREE
+  "Allow showing the parse tree"
+  ${WITH_SHOW_PARSE_TREE_DEFAULT}
+  )
+
 # Utility target to build every executable tagged with ADD_TEST.
 ADD_CUSTOM_TARGET(unittest_all)
 

config.h.cmake

@@ -220,6 +220,7 @@
 #cmakedefine SCRAM_LIB_CONFIGURED
 #cmakedefine WITH_HYPERGRAPH_OPTIMIZER
 #cmakedefine KERBEROS_LIB_SSPI
+#cmakedefine WITH_SHOW_PARSE_TREE
 
 /* Lock Order */
 #cmakedefine WITH_LOCK_ORDER 1

include/my_sqlcommand.h

@@ -171,6 +171,7 @@ enum enum_sql_command {
   SQLCOM_SHOW_CREATE_EVENT,
   SQLCOM_SHOW_EVENTS,
   SQLCOM_SHOW_CREATE_TRIGGER,
+  SQLCOM_SHOW_PARSE_TREE,
   SQLCOM_SHOW_PROFILE,
   SQLCOM_SHOW_PROFILES,
   SQLCOM_SIGNAL,

include/mysql/plugin_audit.h.pp

@@ -304,6 +304,7 @@
   SQLCOM_SHOW_CREATE_EVENT,
   SQLCOM_SHOW_EVENTS,
   SQLCOM_SHOW_CREATE_TRIGGER,
+  SQLCOM_SHOW_PARSE_TREE,
   SQLCOM_SHOW_PROFILE,
   SQLCOM_SHOW_PROFILES,
   SQLCOM_SIGNAL,

mysql-test/r/information_schema_keywords.result

@@ -442,6 +442,7 @@ OWNER	0
 PACK_KEYS	0
 PAGE	0
 PARSER	0
+PARSE_TREE	0
 PARTIAL	0
 PARTITION	1
 PARTITIONING	0

mysql-test/r/mysqld--help-notwin.result

@@ -1926,7 +1926,7 @@ performance-schema-max-socket-classes 10
 performance-schema-max-socket-instances -1
 performance-schema-max-sql-text-length 1024
 performance-schema-max-stage-classes 175
-performance-schema-max-statement-classes 219
+performance-schema-max-statement-classes 220
 performance-schema-max-statement-stack 10
 performance-schema-max-table-handles -1
 performance-schema-max-table-instances -1

mysql-test/r/mysqld--help-win.result

@@ -1938,7 +1938,7 @@ performance-schema-max-socket-classes 10
 performance-schema-max-socket-instances -1
 performance-schema-max-sql-text-length 1024
 performance-schema-max-stage-classes 175
-performance-schema-max-statement-classes 219
+performance-schema-max-statement-classes 220
 performance-schema-max-statement-stack 10
 performance-schema-max-table-handles -1
 performance-schema-max-table-instances -1