Allow to log raw parse tree.

This commit allows to log the raw parse tree in the same way we
currently log the parse tree, rewritten tree, and plan tree.

To avoid unnecessary log noise for users not interested in this
detail, a new GUC option, "debug_print_raw_parse", has been added.

When starting the PostgreSQL process with "-d N", and N is 3 or higher,
debug_print_raw_parse is enabled automatically, alongside
debug_print_parse.

Author: Chao Li <lic@highgo.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tatsuo Ishii <ishii@postgresql.org>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2mcO0Gpo4vd8kPMAFWeJLSp0MeUUnaLdE1x0tSVd-VzUw%40mail.gmail.com

doc/src/sgml/config.sgml

@@ -7383,6 +7383,11 @@ local0.*    /var/log/postgresql
      </varlistentry>
 
      <varlistentry id="guc-debug-print-parse">
+      <term><varname>debug_print_raw_parse</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>debug_print_raw_parse</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
       <term><varname>debug_print_parse</varname> (<type>boolean</type>)
       <indexterm>
        <primary><varname>debug_print_parse</varname> configuration parameter</primary>
@@ -7401,8 +7406,8 @@ local0.*    /var/log/postgresql
       <listitem>
        <para>
         These parameters enable various debugging output to be emitted.
-        When set, they print the resulting parse tree, the query rewriter
+        When set, they print the resulting raw parse tree, the parse tree, the query
-        output, or the execution plan for each executed query.
+        rewriter output, or the execution plan for each executed query.
         These messages are emitted at <literal>LOG</literal> message level, so by
         default they will appear in the server log but will not be sent to the
         client.  You can change that by adjusting
@@ -7422,7 +7427,8 @@ local0.*    /var/log/postgresql
       <listitem>
        <para>
         When set, <varname>debug_pretty_print</varname> indents the messages
-        produced by <varname>debug_print_parse</varname>,
+        produced by <varname>debug_print_raw_parse</varname>,
+        <varname>debug_print_parse</varname>,
         <varname>debug_print_rewritten</varname>, or
         <varname>debug_print_plan</varname>.  This results in more readable
         but much longer output than the <quote>compact</quote> format used when

doc/src/sgml/rules.sgml

@@ -60,6 +60,7 @@
     <acronym>SQL</acronym> statement where the single parts that it is
     built from are stored separately. These query trees can be shown
     in the server log if you set the configuration parameters
+    <varname>debug_print_raw_parse</varname>,
     <varname>debug_print_parse</varname>,
     <varname>debug_print_rewritten</varname>, or
     <varname>debug_print_plan</varname>.  The rule actions are also

src/backend/tcop/postgres.c

@@ -649,6 +649,10 @@ pg_parse_query(const char *query_string)
 
 	TRACE_POSTGRESQL_QUERY_PARSE_DONE(query_string);
 
+	if (Debug_print_raw_parse)
+		elog_node_display(LOG, "raw parse tree", raw_parsetree_list,
+						  Debug_pretty_print);
+
 	return raw_parsetree_list;
 }
 
@@ -3697,7 +3701,10 @@ set_debug_options(int debug_flag, GucContext context, GucSource source)
 	if (debug_flag >= 2)
 		SetConfigOption("log_statement", "all", context, source);
 	if (debug_flag >= 3)
+	{
+		SetConfigOption("debug_print_raw_parse", "true", context, source);
 		SetConfigOption("debug_print_parse", "true", context, source);
+	}
 	if (debug_flag >= 4)
 		SetConfigOption("debug_print_plan", "true", context, source);
 	if (debug_flag >= 5)

src/backend/utils/misc/guc_parameters.dat

@@ -414,6 +414,12 @@
   ifdef => 'DEBUG_NODE_TESTS_ENABLED',
 },
 
+{ name => 'debug_print_raw_parse', type => 'bool', context => 'PGC_USERSET', group => 'LOGGING_WHAT',
+  short_desc => 'Logs each query\'s raw parse tree.',
+  variable => 'Debug_print_raw_parse',
+  boot_val => 'false',
+},
+
 { name => 'debug_print_parse', type => 'bool', context => 'PGC_USERSET', group => 'LOGGING_WHAT',
   short_desc => 'Logs each query\'s parse tree.',
   variable => 'Debug_print_parse',

src/backend/utils/misc/guc_tables.c

@@ -507,6 +507,7 @@ bool		AllowAlterSystem = true;
 bool		log_duration = false;
 bool		Debug_print_plan = false;
 bool		Debug_print_parse = false;
+bool		Debug_print_raw_parse = false;
 bool		Debug_print_rewritten = false;
 bool		Debug_pretty_print = true;
 

src/backend/utils/misc/postgresql.conf.sample

@@ -581,6 +581,7 @@
 
 # - What to Log -
 
+#debug_print_raw_parse = off
 #debug_print_parse = off
 #debug_print_rewritten = off
 #debug_print_plan = off

src/include/utils/guc.h

@@ -247,6 +247,7 @@ typedef enum
 /* GUC vars that are actually defined in guc_tables.c, rather than elsewhere */
 extern PGDLLIMPORT bool Debug_print_plan;
 extern PGDLLIMPORT bool Debug_print_parse;
+extern PGDLLIMPORT bool Debug_print_raw_parse;
 extern PGDLLIMPORT bool Debug_print_rewritten;
 extern PGDLLIMPORT bool Debug_pretty_print;