Separate parse-analysis for utility commands out of parser/analyze.c

(which now deals only in optimizable statements), and put that code
into a new file parser/parse_utilcmd.c.  This helps clarify and enforce
the design rule that utility statements shouldn't be processed during
the regular parse analysis phase; all interpretation of their meaning
should happen after they are given to ProcessUtility to execute.
(We need this because we don't retain any locks for a utility statement
that's in a plan cache, nor have any way to detect that it's stale.)

We are also able to simplify the API for parse_analyze() and related
routines, because they will now always return exactly one Query structure.

In passing, fix bug #3403 concerning trying to add a serial column to
an existing temp table (this is largely Heikki's work, but we needed
all that restructuring to make it safe).

Author: tglsfdc

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.159 2007/06/03 17:06:16 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.160 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -367,7 +367,7 @@ DefineIndex(RangeVar *heapRelation,
 				/*
 				 * This shouldn't happen during CREATE TABLE, but can happen
 				 * during ALTER TABLE.	Keep message in sync with
-				 * transformIndexConstraints() in parser/analyze.c.
+				 * transformIndexConstraints() in parser/parse_utilcmd.c.
 				 */
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),

src/backend/commands/prepare.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2002-2007, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.76 2007/05/25 17:54:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.77 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -55,7 +55,6 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 {
 	Oid		   *argtypes = NULL;
 	int			nargs;
-	List	   *queries;
 	Query	   *query;
 	List	   *query_list,
 			   *plan_list;
@@ -105,9 +104,9 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 	 * Because parse analysis scribbles on the raw querytree, we must make
 	 * a copy to ensure we have a pristine raw tree to cache.  FIXME someday.
 	 */
-	queries = parse_analyze_varparams((Node *) copyObject(stmt->query),
-									  queryString,
-									  &argtypes, &nargs);
+	query = parse_analyze_varparams((Node *) copyObject(stmt->query),
+									queryString,
+									&argtypes, &nargs);
 
 	/*
 	 * Check that all parameter types were determined.
@@ -124,15 +123,8 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 	}
 
 	/*
-	 * Shouldn't get any extra statements, since grammar only allows
-	 * OptimizableStmt
+	 * grammar only allows OptimizableStmt, so this check should be redundant
 	 */
-	if (list_length(queries) != 1)
-		elog(ERROR, "unexpected extra stuff in prepared statement");
-
-	query = (Query *) linitial(queries);
-	Assert(IsA(query, Query));
-
 	switch (query->commandType)
 	{
 		case CMD_SELECT:

src/backend/commands/schemacmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.45 2007/03/23 19:53:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.46 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,7 +24,7 @@
 #include "commands/dbcommands.h"
 #include "commands/schemacmds.h"
 #include "miscadmin.h"
-#include "parser/analyze.h"
+#include "parser/parse_utilcmd.h"
 #include "tcop/utility.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -111,39 +111,31 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString)
 	/*
 	 * Examine the list of commands embedded in the CREATE SCHEMA command, and
 	 * reorganize them into a sequentially executable order with no forward
-	 * references.	Note that the result is still a list of raw parsetrees in
-	 * need of parse analysis --- we cannot, in general, run analyze.c on one
-	 * statement until we have actually executed the prior ones.
+	 * references.	Note that the result is still a list of raw parsetrees
+	 * --- we cannot, in general, run parse analysis on one statement until
+	 * we have actually executed the prior ones.
 	 */
-	parsetree_list = analyzeCreateSchemaStmt(stmt);
+	parsetree_list = transformCreateSchemaStmt(stmt);
 
 	/*
-	 * Analyze and execute each command contained in the CREATE SCHEMA
+	 * Execute each command contained in the CREATE SCHEMA.  Since the
+	 * grammar allows only utility commands in CREATE SCHEMA, there is
+	 * no need to pass them through parse_analyze() or the rewriter;
+	 * we can just hand them straight to ProcessUtility.
 	 */
 	foreach(parsetree_item, parsetree_list)
 	{
-		Node	   *parsetree = (Node *) lfirst(parsetree_item);
-		List	   *querytree_list;
-		ListCell   *querytree_item;
-
-		querytree_list = parse_analyze(parsetree, queryString, NULL, 0);
-
-		foreach(querytree_item, querytree_list)
-		{
-			Query	   *querytree = (Query *) lfirst(querytree_item);
-
-			/* schemas should contain only utility stmts */
-			Assert(querytree->commandType == CMD_UTILITY);
-			/* do this step */
-			ProcessUtility(querytree->utilityStmt,
-						   queryString,
-						   NULL,
-						   false,				/* not top level */
-						   None_Receiver,
-						   NULL);
-			/* make sure later steps can see the object created here */
-			CommandCounterIncrement();
-		}
+		Node	   *stmt = (Node *) lfirst(parsetree_item);
+
+		/* do this step */
+		ProcessUtility(stmt,
+					   queryString,
+					   NULL,
+					   false,				/* not top level */
+					   None_Receiver,
+					   NULL);
+		/* make sure later steps can see the object created here */
+		CommandCounterIncrement();
 	}
 
 	/* Reset search path to normal state */

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.227 2007/06/03 22:16:03 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.228 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,14 +44,14 @@
 #include "optimizer/clauses.h"
 #include "optimizer/plancat.h"
 #include "optimizer/prep.h"
-#include "parser/analyze.h"
 #include "parser/gramparse.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_oper.h"
 #include "parser/parse_relation.h"
 #include "parser/parse_type.h"
+#include "parser/parse_utilcmd.h"
 #include "parser/parser.h"
 #include "rewrite/rewriteDefine.h"
 #include "rewrite/rewriteHandler.h"
@@ -394,7 +394,7 @@ DefineRelation(CreateStmt *stmt, char relkind)
 				add_nonduplicate_constraint(cdef, check, &ncheck);
 		}
 		/*
-		 * analyze.c might have passed some precooked constraints too,
+		 * parse_utilcmd.c might have passed some precooked constraints too,
 		 * due to LIKE tab INCLUDING CONSTRAINTS
 		 */
 		foreach(listptr, stmt->constraints)
@@ -2922,7 +2922,7 @@ find_composite_type_dependencies(Oid typeOid,
  *
  * Adds an additional attribute to a relation making the assumption that
  * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the
- * AT_AddColumn AlterTableCmd by analyze.c and added as independent
+ * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent
  * AlterTableCmd's.
  */
 static void
@@ -3745,9 +3745,9 @@ ATExecDropColumn(Relation rel, const char *colName,
 /*
  * ALTER TABLE ADD INDEX
  *
- * There is no such command in the grammar, but the parser converts UNIQUE
- * and PRIMARY KEY constraints into AT_AddIndex subcommands.  This lets us
- * schedule creation of the index at the appropriate time during ALTER.
+ * There is no such command in the grammar, but parse_utilcmd.c converts
+ * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands.  This lets
+ * us schedule creation of the index at the appropriate time during ALTER.
  */
 static void
 ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
@@ -3766,13 +3766,8 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 	/* suppress notices when rebuilding existing index */
 	quiet = is_rebuild;
 
-	/*
-	 * Run parse analysis.  We don't have convenient access to the query text
-	 * here, but it's probably not worth worrying about.
-	 */
-	stmt = analyzeIndexStmt(stmt, NULL);
+	/* The IndexStmt has already been through transformIndexStmt */
 
-	/* ... and do it */
 	DefineIndex(stmt->relation, /* relation */
 				stmt->idxname,	/* index name */
 				InvalidOid,		/* no predefined OID */
@@ -3806,7 +3801,7 @@ ATExecAddConstraint(AlteredTableInfo *tab, Relation rel, Node *newConstraint)
 				/*
 				 * Currently, we only expect to see CONSTR_CHECK nodes
 				 * arriving here (see the preprocessing done in
-				 * parser/analyze.c).  Use a switch anyway to make it easier
+				 * parse_utilcmd.c).  Use a switch anyway to make it easier
 				 * to add more code later.
 				 */
 				switch (constr->contype)
@@ -5239,17 +5234,27 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 	ListCell   *list_item;
 
 	/*
-	 * We expect that we only have to do raw parsing and parse analysis, not
-	 * any rule rewriting, since these will all be utility statements.
+	 * We expect that we will get only ALTER TABLE and CREATE INDEX statements.
+	 * Hence, there is no need to pass them through parse_analyze() or the
+	 * rewriter, but instead we need to pass them through parse_utilcmd.c
+	 * to make them ready for execution.
 	 */
 	raw_parsetree_list = raw_parser(cmd);
 	querytree_list = NIL;
 	foreach(list_item, raw_parsetree_list)
 	{
-		Node	   *parsetree = (Node *) lfirst(list_item);
-
-		querytree_list = list_concat(querytree_list,
-									 parse_analyze(parsetree, cmd, NULL, 0));
+		Node	   *stmt = (Node *) lfirst(list_item);
+
+		if (IsA(stmt, IndexStmt))
+			querytree_list = lappend(querytree_list,
+									 transformIndexStmt((IndexStmt *) stmt,
+														cmd));
+		else if (IsA(stmt, AlterTableStmt))
+			querytree_list = list_concat(querytree_list,
+							transformAlterTableStmt((AlterTableStmt *) stmt,
+													cmd));
+		else
+			querytree_list = lappend(querytree_list, stmt);
 	}
 
 	/*
@@ -5258,17 +5263,15 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 	 */
 	foreach(list_item, querytree_list)
 	{
-		Query	   *query = (Query *) lfirst(list_item);
+		Node	   *stm = (Node *) lfirst(list_item);
 		Relation	rel;
 		AlteredTableInfo *tab;
 
-		Assert(IsA(query, Query));
-		Assert(query->commandType == CMD_UTILITY);
-		switch (nodeTag(query->utilityStmt))
+		switch (nodeTag(stm))
 		{
 			case T_IndexStmt:
 				{
-					IndexStmt  *stmt = (IndexStmt *) query->utilityStmt;
+					IndexStmt  *stmt = (IndexStmt *) stm;
 					AlterTableCmd *newcmd;
 
 					rel = relation_openrv(stmt->relation, AccessExclusiveLock);
@@ -5283,7 +5286,7 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 				}
 			case T_AlterTableStmt:
 				{
-					AlterTableStmt *stmt = (AlterTableStmt *) query->utilityStmt;
+					AlterTableStmt *stmt = (AlterTableStmt *) stm;
 					ListCell   *lcmd;
 
 					rel = relation_openrv(stmt->relation, AccessExclusiveLock);
@@ -5313,7 +5316,7 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 				}
 			default:
 				elog(ERROR, "unexpected statement type: %d",
-					 (int) nodeTag(query->utilityStmt));
+					 (int) nodeTag(stm));
 		}
 	}
 }

src/backend/commands/view.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.100 2007/03/13 00:33:40 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.101 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -351,7 +351,6 @@ UpdateRangeTableOfViewParse(Oid viewOid, Query *viewParse)
 void
 DefineView(ViewStmt *stmt, const char *queryString)
 {
-	List	   *stmts;
 	Query	   *viewParse;
 	Oid			viewOid;
 	RangeVar   *view;
@@ -363,15 +362,12 @@ DefineView(ViewStmt *stmt, const char *queryString)
 	 * Since parse analysis scribbles on its input, copy the raw parse tree;
 	 * this ensures we don't corrupt a prepared statement, for example.
 	 */
-	stmts = parse_analyze((Node *) copyObject(stmt->query),
-						  queryString, NULL, 0);
+	viewParse = parse_analyze((Node *) copyObject(stmt->query),
+							  queryString, NULL, 0);
 
 	/*
 	 * The grammar should ensure that the result is a single SELECT Query.
 	 */
-	if (list_length(stmts) != 1)
-		elog(ERROR, "unexpected parse analysis result");
-	viewParse = (Query *) linitial(stmts);
 	if (!IsA(viewParse, Query) ||
 		viewParse->commandType != CMD_SELECT)
 		elog(ERROR, "unexpected parse analysis result");

src/backend/nodes/makefuncs.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.55 2007/03/17 00:11:03 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.56 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -134,6 +134,20 @@ flatCopyTargetEntry(TargetEntry *src_tle)
 	return tle;
 }
 
+/*
+ * makeFromExpr -
+ *	  creates a FromExpr node
+ */
+FromExpr *
+makeFromExpr(List *fromlist, Node *quals)
+{
+	FromExpr   *f = makeNode(FromExpr);
+
+	f->fromlist = fromlist;
+	f->quals = quals;
+	return f;
+}
+
 /*
  * makeConst -
  *	  creates a Const node