Support CTE/JOIN usage for PIVOT operator (#299)

This commit fixed an issue that CTE and JOIN cannot be used with pivot operator.

We added 1 field (Node *context) in FuncExpr Struct to store pivot additional information. FuncExpr will carry the pivot information to ExecMakeTableFunctionResult. In this function, we pass the pivot information into two newly added FunctionCallInfo that we can retrieve at bbf_pivot function.

Task: BABEL-4713, BABEL-4714, BABEL-4795 
Signed-off-by: Yanjie Xu <[email protected]>

Author: RIC06X

src/backend/executor/execSRF.c

@@ -25,6 +25,7 @@
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
+#include "parser/parser.h"
 #include "parser/parse_coerce.h"
 #include "pgstat.h"
 #include "utils/acl.h"
@@ -33,6 +34,8 @@
 #include "utils/memutils.h"
 #include "utils/typcache.h"
 
+/* Hook to set TSQL pivot data to fcinfo */
+pass_pivot_data_to_fcinfo_hook_type pass_pivot_data_to_fcinfo_hook = NULL;
 
 /* static function decls */
 static void init_sexpr(Oid foid, Oid input_collation, Expr *node,
@@ -202,7 +205,12 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		/* Treat setexpr as a generic expression */
 		InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 	}
-
+	
+	if (sql_dialect == SQL_DIALECT_TSQL && pass_pivot_data_to_fcinfo_hook)
+	{
+		(pass_pivot_data_to_fcinfo_hook)(fcinfo, setexpr->expr);
+	}
+		
 	/*
 	 * Switch to short-lived context for calling the function or expression.
 	 */

src/backend/nodes/makefuncs.c

@@ -534,6 +534,7 @@ makeFuncExpr(Oid funcid, Oid rettype, List *args,
 	funcexpr->inputcollid = inputcollid;
 	funcexpr->args = args;
 	funcexpr->location = -1;
+	funcexpr->context = NULL;
 
 	return funcexpr;
 }
@@ -600,6 +601,7 @@ makeFuncCall(List *name, List *args, CoercionForm funcformat, int location)
 	n->func_variadic = false;
 	n->funcformat = funcformat;
 	n->location = location;
+	n->context = NULL;
 	return n;
 }
 

src/backend/optimizer/util/clauses.c

@@ -2601,6 +2601,7 @@ eval_const_expressions_mutator(Node *node,
 				newexpr->inputcollid = expr->inputcollid;
 				newexpr->args = args;
 				newexpr->location = expr->location;
+				newexpr->context = expr->context;
 				return (Node *) newexpr;
 			}
 		case T_OpExpr:
@@ -4562,6 +4563,7 @@ evaluate_function(Oid funcid, Oid result_type, int32 result_typmod,
 	newexpr->inputcollid = input_collid;
 	newexpr->args = args;
 	newexpr->location = -1;
+	newexpr->context = NULL;
 
 	return evaluate_expr((Expr *) newexpr, result_type, result_typmod,
 						 result_collid);
@@ -4674,6 +4676,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
 	fexpr->inputcollid = input_collid;
 	fexpr->args = args;
 	fexpr->location = -1;
+	fexpr->context = NULL;
 
 	/* Fetch the function body */
 	tmp = SysCacheGetAttrNotNull(PROCOID, func_tuple, Anum_pg_proc_prosrc);

src/backend/parser/analyze.c

@@ -89,7 +89,7 @@ pre_transform_setop_tree_hook_type pre_transform_setop_tree_hook = NULL;
 /* Hook to reset a query's targetlist after modification in pre_transfrom_sort_clause */
 pre_transform_setop_sort_clause_hook_type pre_transform_setop_sort_clause_hook = NULL;
 
-/* Hooks for transform TSQL pivot clause in select stmt */
+/* Hook to transform TSQL pivot clause in select stmt */
 transform_pivot_clause_hook_type transform_pivot_clause_hook = NULL;
 
 static Query *transformOptionalSelectInto(ParseState *pstate, Node *parseTree);

src/backend/parser/parse_func.c

@@ -765,6 +765,10 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
 		/* funccollid and inputcollid will be set by parse_collate.c */
 		funcexpr->args = fargs;
 		funcexpr->location = location;
+		funcexpr->context = NULL;
+		
+		if (fn != NULL)
+			funcexpr->context = copyObject(fn->context);
 
 		retval = (Node *) funcexpr;
 	}

src/include/executor/executor.h

@@ -473,6 +473,8 @@ extern Datum ExecMakeFunctionResultSet(SetExprState *fcache,
 									   MemoryContext argContext,
 									   bool *isNull,
 									   ExprDoneCond *isDone);
+typedef void (*pass_pivot_data_to_fcinfo_hook_type)(FunctionCallInfo fcinfo, Expr *expr);
+extern PGDLLEXPORT pass_pivot_data_to_fcinfo_hook_type pass_pivot_data_to_fcinfo_hook;
 
 /*
  * prototypes from functions in execScan.c

src/include/nodes/parsenodes.h

@@ -432,6 +432,7 @@ typedef struct FuncCall
 	bool		func_variadic;	/* last argument was labeled VARIADIC */
 	CoercionForm funcformat;	/* how to display this node */
 	int			location;		/* token location, or -1 if unknown */
+	Node 	   *context;		/* pass necessary info through planner and executor */
 } FuncCall;
 
 /*

src/include/nodes/primnodes.h

@@ -695,6 +695,8 @@ typedef struct FuncExpr
 	List	   *args;
 	/* token location, or -1 if unknown */
 	int			location;
+	/* pass necessary info through planner and executor */
+	Node 	   *context pg_node_attr(query_jumble_ignore, read_write_ignore, read_as(NULL));
 } FuncExpr;
 
 /*