uqa-pg-query 0.1.6

/*--------------------------------------------------------------------
 * Symbols referenced in this file:
 * - plpgsql_compile_inline
 * - plpgsql_error_funcname
 * - plpgsql_check_syntax
 * - plpgsql_curr_compile
 * - plpgsql_compile_tmp_cxt
 * - plpgsql_DumpExecTree
 * - plpgsql_start_datums
 * - plpgsql_nDatums
 * - plpgsql_Datums
 * - datums_alloc
 * - datums_last
 * - plpgsql_build_variable
 * - plpgsql_adddatum
 * - plpgsql_build_record
 * - plpgsql_build_datatype
 * - build_datatype
 * - plpgsql_parse_tripword
 * - plpgsql_build_recfield
 * - plpgsql_parse_dblword
 * - plpgsql_parse_word
 * - plpgsql_add_initdatums
 * - plpgsql_recognize_err_condition
 * - exception_label_map
 * - plpgsql_parse_err_condition
 * - plpgsql_parse_wordtype
 * - plpgsql_parse_wordrowtype
 * - plpgsql_parse_cwordtype
 * - plpgsql_parse_cwordrowtype
 * - plpgsql_build_datatype_arrayof
 * - plpgsql_finish_datums
 * - plpgsql_compile_error_callback
 * - add_dummy_return
 * - plpgsql_compile_callback
 * - add_parameter_name
 * - build_row_from_vars
 *--------------------------------------------------------------------
 */

/*-------------------------------------------------------------------------
 *
 * pl_comp.c		- Compiler part of the PL/pgSQL
 *			  procedural language
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  src/pl/plpgsql/src/pl_comp.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include <ctype.h>

#include "access/htup_details.h"
#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "nodes/makefuncs.h"
#include "parser/parse_node.h"
#include "plpgsql.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/regproc.h"
#include "utils/syscache.h"
#include "utils/typcache.h"

/* ----------
 * Our own local and global variables
 * ----------
 */
static __thread int	datums_alloc;

__thread int			plpgsql_nDatums;

__thread PLpgSQL_datum **plpgsql_Datums;

static __thread int	datums_last;


__thread char	   *plpgsql_error_funcname;

__thread bool		plpgsql_DumpExecTree = false;

__thread bool		plpgsql_check_syntax = false;


__thread PLpgSQL_function *plpgsql_curr_compile;


/* A context appropriate for short-term allocs during compilation */
__thread MemoryContext plpgsql_compile_tmp_cxt;


/* ----------
 * Lookup table for EXCEPTION condition names
 * ----------
 */
typedef struct
{
	const char *label;
	int			sqlerrstate;
} ExceptionLabelMap;

static const ExceptionLabelMap exception_label_map[] = {
#include "plerrcodes.h"
	{NULL, 0}
};


/* ----------
 * static prototypes
 * ----------
 */
static void plpgsql_compile_error_callback(void *arg);
static void add_parameter_name(PLpgSQL_nsitem_type itemtype, int itemno, const char *name);
static void add_dummy_return(PLpgSQL_function *function);
static Node *plpgsql_pre_column_ref(ParseState *pstate, ColumnRef *cref);
static Node *plpgsql_post_column_ref(ParseState *pstate, ColumnRef *cref, Node *var);
static Node *plpgsql_param_ref(ParseState *pstate, ParamRef *pref);
static Node *resolve_column_ref(ParseState *pstate, PLpgSQL_expr *expr,
								ColumnRef *cref, bool error_if_no_field);
static Node *make_datum_param(PLpgSQL_expr *expr, int dno, int location);
static PLpgSQL_row *build_row_from_vars(PLpgSQL_variable **vars, int numvars);
static PLpgSQL_type *build_datatype(HeapTuple typeTup, int32 typmod,
									Oid collation, TypeName *origtypname);

/* ----------
 * plpgsql_compile		Make an execution tree for a PL/pgSQL function.
 *
 * If forValidator is true, we're only compiling for validation purposes,
 * and so some checks are skipped.
 *
 * Note: it's important for this to fall through quickly if the function
 * has already been compiled.
 * ----------
 */


struct compile_error_callback_arg
{
	const char *proc_source;
	yyscan_t	yyscanner;
};

/*
 * This is the slow part of plpgsql_compile().
 *
 * The passed-in "cfunc" struct is expected to be zeroes, except
 * for the CachedFunction fields, which we don't touch here.
 *
 * While compiling a function, the CurrentMemoryContext is the
 * per-function memory context of the function we are compiling. That
 * means a palloc() will allocate storage with the same lifetime as
 * the function itself.
 *
 * Because palloc()'d storage will not be immediately freed, temporary
 * allocations should either be performed in a short-lived memory
 * context or explicitly pfree'd. Since not all backend functions are
 * careful about pfree'ing their allocations, it is also wise to
 * switch into a short-term context before calling into the
 * backend. An appropriate context for performing short-term
 * allocations is the plpgsql_compile_tmp_cxt.
 *
 * NB: this code is not re-entrant.  We assume that nothing we do here could
 * result in the invocation of another plpgsql function.
 */
void
plpgsql_compile_callback(FunctionCallInfo fcinfo,
						 HeapTuple procTup,
						 const CachedFunctionHashKey *hashkey,
						 CachedFunction *cfunc,
						 bool forValidator)
{
	PLpgSQL_function *function = (PLpgSQL_function *) cfunc;
	Form_pg_proc procStruct = (Form_pg_proc) GETSTRUCT(procTup);
	bool		is_dml_trigger = CALLED_AS_TRIGGER(fcinfo);
	bool		is_event_trigger = CALLED_AS_EVENT_TRIGGER(fcinfo);
	yyscan_t	scanner;
	Datum		prosrcdatum;
	char	   *proc_source;
	HeapTuple	typeTup;
	Form_pg_type typeStruct;
	PLpgSQL_variable *var;
	PLpgSQL_rec *rec;
	int			i;
	struct compile_error_callback_arg cbarg;
	ErrorContextCallback plerrcontext;
	int			parse_rc;
	Oid			rettypeid;
	int			numargs;
	int			num_in_args = 0;
	int			num_out_args = 0;
	Oid		   *argtypes;
	char	  **argnames;
	char	   *argmodes;
	int		   *in_arg_varnos = NULL;
	PLpgSQL_variable **out_arg_variables;
	MemoryContext func_cxt;

	/*
	 * Setup the scanner input and error info.
	 */
	prosrcdatum = SysCacheGetAttrNotNull(PROCOID, procTup, Anum_pg_proc_prosrc);
	proc_source = TextDatumGetCString(prosrcdatum);
	scanner = plpgsql_scanner_init(proc_source);

	plpgsql_error_funcname = pstrdup(NameStr(procStruct->proname));

	/*
	 * Setup error traceback support for ereport()
	 */
	cbarg.proc_source = forValidator ? proc_source : NULL;
	cbarg.yyscanner = scanner;
	plerrcontext.callback = plpgsql_compile_error_callback;
	plerrcontext.arg = &cbarg;
	plerrcontext.previous = error_context_stack;
	error_context_stack = &plerrcontext;

	/*
	 * Do extra syntax checks when validating the function definition. We skip
	 * this when actually compiling functions for execution, for performance
	 * reasons.
	 */
	plpgsql_check_syntax = forValidator;
	plpgsql_curr_compile = function;

	/*
	 * All the permanent output of compilation (e.g. parse tree) is kept in a
	 * per-function memory context, so it can be reclaimed easily.
	 *
	 * While the func_cxt needs to be long-lived, we initially make it a child
	 * of the assumed-short-lived caller's context, and reparent it under
	 * CacheMemoryContext only upon success.  This arrangement avoids memory
	 * leakage during compilation of a faulty function.
	 */
	func_cxt = AllocSetContextCreate(CurrentMemoryContext,
									 "PL/pgSQL function",
									 ALLOCSET_DEFAULT_SIZES);
	plpgsql_compile_tmp_cxt = MemoryContextSwitchTo(func_cxt);

	function->fn_signature = format_procedure(fcinfo->flinfo->fn_oid);
	MemoryContextSetIdentifier(func_cxt, function->fn_signature);
	function->fn_oid = fcinfo->flinfo->fn_oid;
	function->fn_input_collation = fcinfo->fncollation;
	function->fn_cxt = func_cxt;
	function->out_param_varno = -1; /* set up for no OUT param */
	function->resolve_option = plpgsql_variable_conflict;
	function->print_strict_params = plpgsql_print_strict_params;
	/* only promote extra warnings and errors at CREATE FUNCTION time */
	function->extra_warnings = forValidator ? plpgsql_extra_warnings : 0;
	function->extra_errors = forValidator ? plpgsql_extra_errors : 0;

	if (is_dml_trigger)
		function->fn_is_trigger = PLPGSQL_DML_TRIGGER;
	else if (is_event_trigger)
		function->fn_is_trigger = PLPGSQL_EVENT_TRIGGER;
	else
		function->fn_is_trigger = PLPGSQL_NOT_TRIGGER;

	function->fn_prokind = procStruct->prokind;

	function->nstatements = 0;
	function->requires_procedure_resowner = false;
	function->has_exception_block = false;

	/*
	 * Initialize the compiler, particularly the namespace stack.  The
	 * outermost namespace contains function parameters and other special
	 * variables (such as FOUND), and is named after the function itself.
	 */
	plpgsql_ns_init();
	plpgsql_ns_push(NameStr(procStruct->proname), PLPGSQL_LABEL_BLOCK);
	plpgsql_DumpExecTree = false;
	plpgsql_start_datums();

	switch (function->fn_is_trigger)
	{
		case PLPGSQL_NOT_TRIGGER:

			/*
			 * Fetch info about the procedure's parameters. Allocations aren't
			 * needed permanently, so make them in tmp cxt.
			 *
			 * We also need to resolve any polymorphic input or output
			 * argument types.  In validation mode we won't be able to, so we
			 * arbitrarily assume we are dealing with integers.
			 */
			MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);

			numargs = get_func_arg_info(procTup,
										&argtypes, &argnames, &argmodes);

			cfunc_resolve_polymorphic_argtypes(numargs, argtypes, argmodes,
											   fcinfo->flinfo->fn_expr,
											   forValidator,
											   plpgsql_error_funcname);

			in_arg_varnos = (int *) palloc(numargs * sizeof(int));
			out_arg_variables = (PLpgSQL_variable **) palloc(numargs * sizeof(PLpgSQL_variable *));

			MemoryContextSwitchTo(func_cxt);

			/*
			 * Create the variables for the procedure's parameters.
			 */
			for (i = 0; i < numargs; i++)
			{
				char		buf[32];
				Oid			argtypeid = argtypes[i];
				char		argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
				PLpgSQL_type *argdtype;
				PLpgSQL_variable *argvariable;
				PLpgSQL_nsitem_type argitemtype;

				/* Create $n name for variable */
				snprintf(buf, sizeof(buf), "$%d", i + 1);

				/* Create datatype info */
				argdtype = plpgsql_build_datatype(argtypeid,
												  -1,
												  function->fn_input_collation,
												  NULL);

				/* Disallow pseudotype argument */
				/* (note we already replaced polymorphic types) */
				/* (build_variable would do this, but wrong message) */
				if (argdtype->ttype == PLPGSQL_TTYPE_PSEUDO)
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("PL/pgSQL functions cannot accept type %s",
									format_type_be(argtypeid))));

				/*
				 * Build variable and add to datum list.  If there's a name
				 * for the argument, use that as refname, else use $n name.
				 */
				argvariable = plpgsql_build_variable((argnames &&
													  argnames[i][0] != '\0') ?
													 argnames[i] : buf,
													 0, argdtype, false);

				if (argvariable->dtype == PLPGSQL_DTYPE_VAR)
				{
					argitemtype = PLPGSQL_NSTYPE_VAR;
				}
				else
				{
					Assert(argvariable->dtype == PLPGSQL_DTYPE_REC);
					argitemtype = PLPGSQL_NSTYPE_REC;
				}

				/* Remember arguments in appropriate arrays */
				if (argmode == PROARGMODE_IN ||
					argmode == PROARGMODE_INOUT ||
					argmode == PROARGMODE_VARIADIC)
					in_arg_varnos[num_in_args++] = argvariable->dno;
				if (argmode == PROARGMODE_OUT ||
					argmode == PROARGMODE_INOUT ||
					argmode == PROARGMODE_TABLE)
					out_arg_variables[num_out_args++] = argvariable;

				/* Add to namespace under the $n name */
				add_parameter_name(argitemtype, argvariable->dno, buf);

				/* If there's a name for the argument, make an alias */
				if (argnames && argnames[i][0] != '\0')
					add_parameter_name(argitemtype, argvariable->dno,
									   argnames[i]);
			}

			/*
			 * If there's just one OUT parameter, out_param_varno points
			 * directly to it.  If there's more than one, build a row that
			 * holds all of them.  Procedures return a row even for one OUT
			 * parameter.
			 */
			if (num_out_args > 1 ||
				(num_out_args == 1 && function->fn_prokind == PROKIND_PROCEDURE))
			{
				PLpgSQL_row *row = build_row_from_vars(out_arg_variables,
													   num_out_args);

				plpgsql_adddatum((PLpgSQL_datum *) row);
				function->out_param_varno = row->dno;
			}
			else if (num_out_args == 1)
				function->out_param_varno = out_arg_variables[0]->dno;

			/*
			 * Check for a polymorphic returntype. If found, use the actual
			 * returntype type from the caller's FuncExpr node, if we have
			 * one.  (In validation mode we arbitrarily assume we are dealing
			 * with integers.)
			 *
			 * Note: errcode is FEATURE_NOT_SUPPORTED because it should always
			 * work; if it doesn't we're in some context that fails to make
			 * the info available.
			 */
			rettypeid = procStruct->prorettype;
			if (IsPolymorphicType(rettypeid))
			{
				if (forValidator)
				{
					if (rettypeid == ANYARRAYOID ||
						rettypeid == ANYCOMPATIBLEARRAYOID)
						rettypeid = INT4ARRAYOID;
					else if (rettypeid == ANYRANGEOID ||
							 rettypeid == ANYCOMPATIBLERANGEOID)
						rettypeid = INT4RANGEOID;
					else if (rettypeid == ANYMULTIRANGEOID)
						rettypeid = INT4MULTIRANGEOID;
					else		/* ANYELEMENT or ANYNONARRAY or ANYCOMPATIBLE */
						rettypeid = INT4OID;
					/* XXX what could we use for ANYENUM? */
				}
				else
				{
					rettypeid = get_fn_expr_rettype(fcinfo->flinfo);
					if (!OidIsValid(rettypeid))
						ereport(ERROR,
								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
								 errmsg("could not determine actual return type "
										"for polymorphic function \"%s\"",
										plpgsql_error_funcname)));
				}
			}

			/*
			 * Normal function has a defined returntype
			 */
			function->fn_rettype = rettypeid;
			function->fn_retset = procStruct->proretset;

			/*
			 * Lookup the function's return type
			 */
			typeTup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(rettypeid));
			if (!HeapTupleIsValid(typeTup))
				elog(ERROR, "cache lookup failed for type %u", rettypeid);
			typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

			/* Disallow pseudotype result, except VOID or RECORD */
			/* (note we already replaced polymorphic types) */
			if (typeStruct->typtype == TYPTYPE_PSEUDO)
			{
				if (rettypeid == VOIDOID ||
					rettypeid == RECORDOID)
					 /* okay */ ;
				else if (rettypeid == TRIGGEROID || rettypeid == EVENT_TRIGGEROID)
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("trigger functions can only be called as triggers")));
				else
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("PL/pgSQL functions cannot return type %s",
									format_type_be(rettypeid))));
			}

			function->fn_retistuple = type_is_rowtype(rettypeid);
			function->fn_retisdomain = (typeStruct->typtype == TYPTYPE_DOMAIN);
			function->fn_retbyval = typeStruct->typbyval;
			function->fn_rettyplen = typeStruct->typlen;

			/*
			 * install $0 reference, but only for polymorphic return types,
			 * and not when the return is specified through an output
			 * parameter.
			 */
			if (IsPolymorphicType(procStruct->prorettype) &&
				num_out_args == 0)
			{
				(void) plpgsql_build_variable("$0", 0,
											  build_datatype(typeTup,
															 -1,
															 function->fn_input_collation,
															 NULL),
											  true);
			}

			ReleaseSysCache(typeTup);
			break;

		case PLPGSQL_DML_TRIGGER:
			/* Trigger procedure's return type is unknown yet */
			function->fn_rettype = InvalidOid;
			function->fn_retbyval = false;
			function->fn_retistuple = true;
			function->fn_retisdomain = false;
			function->fn_retset = false;

			/* shouldn't be any declared arguments */
			if (procStruct->pronargs != 0)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
						 errmsg("trigger functions cannot have declared arguments"),
						 errhint("The arguments of the trigger can be accessed through TG_NARGS and TG_ARGV instead.")));

			/* Add the record for referencing NEW ROW */
			rec = plpgsql_build_record("new", 0, NULL, RECORDOID, true);
			function->new_varno = rec->dno;

			/* Add the record for referencing OLD ROW */
			rec = plpgsql_build_record("old", 0, NULL, RECORDOID, true);
			function->old_varno = rec->dno;

			/* Add the variable tg_name */
			var = plpgsql_build_variable("tg_name", 0,
										 plpgsql_build_datatype(NAMEOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_NAME;

			/* Add the variable tg_when */
			var = plpgsql_build_variable("tg_when", 0,
										 plpgsql_build_datatype(TEXTOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_WHEN;

			/* Add the variable tg_level */
			var = plpgsql_build_variable("tg_level", 0,
										 plpgsql_build_datatype(TEXTOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_LEVEL;

			/* Add the variable tg_op */
			var = plpgsql_build_variable("tg_op", 0,
										 plpgsql_build_datatype(TEXTOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_OP;

			/* Add the variable tg_relid */
			var = plpgsql_build_variable("tg_relid", 0,
										 plpgsql_build_datatype(OIDOID,
																-1,
																InvalidOid,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_RELID;

			/* Add the variable tg_relname */
			var = plpgsql_build_variable("tg_relname", 0,
										 plpgsql_build_datatype(NAMEOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_TABLE_NAME;

			/* tg_table_name is now preferred to tg_relname */
			var = plpgsql_build_variable("tg_table_name", 0,
										 plpgsql_build_datatype(NAMEOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_TABLE_NAME;

			/* add the variable tg_table_schema */
			var = plpgsql_build_variable("tg_table_schema", 0,
										 plpgsql_build_datatype(NAMEOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_TABLE_SCHEMA;

			/* Add the variable tg_nargs */
			var = plpgsql_build_variable("tg_nargs", 0,
										 plpgsql_build_datatype(INT4OID,
																-1,
																InvalidOid,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_NARGS;

			/* Add the variable tg_argv */
			var = plpgsql_build_variable("tg_argv", 0,
										 plpgsql_build_datatype(TEXTARRAYOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_ARGV;

			break;

		case PLPGSQL_EVENT_TRIGGER:
			function->fn_rettype = VOIDOID;
			function->fn_retbyval = false;
			function->fn_retistuple = true;
			function->fn_retisdomain = false;
			function->fn_retset = false;

			/* shouldn't be any declared arguments */
			if (procStruct->pronargs != 0)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
						 errmsg("event trigger functions cannot have declared arguments")));

			/* Add the variable tg_event */
			var = plpgsql_build_variable("tg_event", 0,
										 plpgsql_build_datatype(TEXTOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_EVENT;

			/* Add the variable tg_tag */
			var = plpgsql_build_variable("tg_tag", 0,
										 plpgsql_build_datatype(TEXTOID,
																-1,
																function->fn_input_collation,
																NULL),
										 true);
			Assert(var->dtype == PLPGSQL_DTYPE_VAR);
			var->dtype = PLPGSQL_DTYPE_PROMISE;
			((PLpgSQL_var *) var)->promise = PLPGSQL_PROMISE_TG_TAG;

			break;

		default:
			elog(ERROR, "unrecognized function typecode: %d",
				 (int) function->fn_is_trigger);
			break;
	}

	/* Remember if function is STABLE/IMMUTABLE */
	function->fn_readonly = (procStruct->provolatile != PROVOLATILE_VOLATILE);

	/*
	 * Create the magic FOUND variable.
	 */
	var = plpgsql_build_variable("found", 0,
								 plpgsql_build_datatype(BOOLOID,
														-1,
														InvalidOid,
														NULL),
								 true);
	function->found_varno = var->dno;

	/*
	 * Now parse the function's text
	 */
	parse_rc = plpgsql_yyparse(&function->action, scanner);
	if (parse_rc != 0)
		elog(ERROR, "plpgsql parser returned %d", parse_rc);

	plpgsql_scanner_finish(scanner);
	pfree(proc_source);

	/*
	 * If it has OUT parameters or returns VOID or returns a set, we allow
	 * control to fall off the end without an explicit RETURN statement. The
	 * easiest way to implement this is to add a RETURN statement to the end
	 * of the statement list during parsing.
	 */
	if (num_out_args > 0 || function->fn_rettype == VOIDOID ||
		function->fn_retset)
		add_dummy_return(function);

	/*
	 * Complete the function's info
	 */
	function->fn_nargs = procStruct->pronargs;
	for (i = 0; i < function->fn_nargs; i++)
		function->fn_argvarnos[i] = in_arg_varnos[i];

	plpgsql_finish_datums(function);

	if (function->has_exception_block)
		plpgsql_mark_local_assignment_targets(function);

	/* Debug dump for completed functions */
	if (plpgsql_DumpExecTree)
		plpgsql_dumptree(function);

	/*
	 * All is well, so make the func_cxt long-lived
	 */
	MemoryContextSetParent(func_cxt, CacheMemoryContext);

	/*
	 * Pop the error context stack
	 */
	error_context_stack = plerrcontext.previous;
	plpgsql_error_funcname = NULL;

	plpgsql_check_syntax = false;

	MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);
	plpgsql_compile_tmp_cxt = NULL;
}

/* ----------
 * plpgsql_compile_inline	Make an execution tree for an anonymous code block.
 *
 * Note: this is generally parallel to plpgsql_compile_callback(); is it worth
 * trying to merge the two?
 *
 * Note: we assume the block will be thrown away so there is no need to build
 * persistent data structures.
 * ----------
 */
PLpgSQL_function *
plpgsql_compile_inline(char *proc_source)
{
	yyscan_t	scanner;
	char	   *func_name = "inline_code_block";
	PLpgSQL_function *function;
	struct compile_error_callback_arg cbarg;
	ErrorContextCallback plerrcontext;
	PLpgSQL_variable *var;
	int			parse_rc;
	MemoryContext func_cxt;

	/*
	 * Setup the scanner input and error info.
	 */
	scanner = plpgsql_scanner_init(proc_source);

	plpgsql_error_funcname = func_name;

	/*
	 * Setup error traceback support for ereport()
	 */
	cbarg.proc_source = proc_source;
	cbarg.yyscanner = scanner;
	plerrcontext.callback = plpgsql_compile_error_callback;
	plerrcontext.arg = &cbarg;
	plerrcontext.previous = error_context_stack;
	error_context_stack = &plerrcontext;

	/* Do extra syntax checking if check_function_bodies is on */
	plpgsql_check_syntax = check_function_bodies;

	/* Function struct does not live past current statement */
	function = (PLpgSQL_function *) palloc0(sizeof(PLpgSQL_function));

	plpgsql_curr_compile = function;

	/*
	 * All the rest of the compile-time storage (e.g. parse tree) is kept in
	 * its own memory context, so it can be reclaimed easily.
	 */
	func_cxt = AllocSetContextCreate(CurrentMemoryContext,
									 "PL/pgSQL inline code context",
									 ALLOCSET_DEFAULT_SIZES);
	plpgsql_compile_tmp_cxt = MemoryContextSwitchTo(func_cxt);

	function->fn_signature = pstrdup(func_name);
	function->fn_is_trigger = PLPGSQL_NOT_TRIGGER;
	function->fn_input_collation = InvalidOid;
	function->fn_cxt = func_cxt;
	function->out_param_varno = -1; /* set up for no OUT param */
	function->resolve_option = plpgsql_variable_conflict;
	function->print_strict_params = plpgsql_print_strict_params;

	/*
	 * don't do extra validation for inline code as we don't want to add spam
	 * at runtime
	 */
	function->extra_warnings = 0;
	function->extra_errors = 0;

	function->nstatements = 0;
	function->requires_procedure_resowner = false;
	function->has_exception_block = false;

	plpgsql_ns_init();
	plpgsql_ns_push(func_name, PLPGSQL_LABEL_BLOCK);
	plpgsql_DumpExecTree = false;
	plpgsql_start_datums();

	/* Set up as though in a function returning VOID */
	function->fn_rettype = VOIDOID;
	function->fn_retset = false;
	function->fn_retistuple = false;
	function->fn_retisdomain = false;
	function->fn_prokind = PROKIND_FUNCTION;
	/* a bit of hardwired knowledge about type VOID here */
	function->fn_retbyval = true;
	function->fn_rettyplen = sizeof(int32);

	/*
	 * Remember if function is STABLE/IMMUTABLE.  XXX would it be better to
	 * set this true inside a read-only transaction?  Not clear.
	 */
	function->fn_readonly = false;

	/*
	 * Create the magic FOUND variable.
	 */
	var = plpgsql_build_variable("found", 0,
								 plpgsql_build_datatype(BOOLOID,
														-1,
														InvalidOid,
														NULL),
								 true);
	function->found_varno = var->dno;

	/*
	 * Now parse the function's text
	 */
	parse_rc = plpgsql_yyparse(&function->action, scanner);
	if (parse_rc != 0)
		elog(ERROR, "plpgsql parser returned %d", parse_rc);

	plpgsql_scanner_finish(scanner);

	/*
	 * If it returns VOID (always true at the moment), we allow control to
	 * fall off the end without an explicit RETURN statement.
	 */
	if (function->fn_rettype == VOIDOID)
		add_dummy_return(function);

	/*
	 * Complete the function's info
	 */
	function->fn_nargs = 0;

	plpgsql_finish_datums(function);

	if (function->has_exception_block)
		plpgsql_mark_local_assignment_targets(function);

	/* Debug dump for completed functions */
	if (plpgsql_DumpExecTree)
		plpgsql_dumptree(function);

	/*
	 * Pop the error context stack
	 */
	error_context_stack = plerrcontext.previous;
	plpgsql_error_funcname = NULL;

	plpgsql_check_syntax = false;

	MemoryContextSwitchTo(plpgsql_compile_tmp_cxt);
	plpgsql_compile_tmp_cxt = NULL;
	return function;
}


/*
 * error context callback to let us supply a call-stack traceback.
 * If we are validating or executing an anonymous code block, the function
 * source text is passed as an argument.
 */
static void
plpgsql_compile_error_callback(void *arg)
{
	struct compile_error_callback_arg *cbarg = (struct compile_error_callback_arg *) arg;
	yyscan_t	yyscanner = cbarg->yyscanner;

	if (cbarg->proc_source)
	{
		/*
		 * Try to convert syntax error position to reference text of original
		 * CREATE FUNCTION or DO command.
		 */
		if (function_parse_error_transpose(cbarg->proc_source))
			return;

		/*
		 * Done if a syntax error position was reported; otherwise we have to
		 * fall back to a "near line N" report.
		 */
	}

	if (plpgsql_error_funcname)
		errcontext("compilation of PL/pgSQL function \"%s\" near line %d",
				   plpgsql_error_funcname, plpgsql_latest_lineno(yyscanner));
}


/*
 * Add a name for a function parameter to the function's namespace
 */
static void
add_parameter_name(PLpgSQL_nsitem_type itemtype, int itemno, const char *name)
{
	/*
	 * Before adding the name, check for duplicates.  We need this even though
	 * functioncmds.c has a similar check, because that code explicitly
	 * doesn't complain about conflicting IN and OUT parameter names.  In
	 * plpgsql, such names are in the same namespace, so there is no way to
	 * disambiguate.
	 */
	if (plpgsql_ns_lookup(plpgsql_ns_top(), true,
						  name, NULL, NULL,
						  NULL) != NULL)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				 errmsg("parameter name \"%s\" used more than once",
						name)));

	/* OK, add the name */
	plpgsql_ns_additem(itemtype, itemno, name);
}

/*
 * Add a dummy RETURN statement to the given function's body
 */
static void
add_dummy_return(PLpgSQL_function *function)
{
	/*
	 * If the outer block has an EXCEPTION clause, we need to make a new outer
	 * block, since the added RETURN shouldn't act like it is inside the
	 * EXCEPTION clause.  Likewise, if it has a label, wrap it in a new outer
	 * block so that EXIT doesn't skip the RETURN.
	 */
	if (function->action->exceptions != NULL ||
		function->action->label != NULL)
	{
		PLpgSQL_stmt_block *new;

		new = palloc0(sizeof(PLpgSQL_stmt_block));
		new->cmd_type = PLPGSQL_STMT_BLOCK;
		new->stmtid = ++function->nstatements;
		new->body = list_make1(function->action);

		function->action = new;
	}
	if (function->action->body == NIL ||
		((PLpgSQL_stmt *) llast(function->action->body))->cmd_type != PLPGSQL_STMT_RETURN)
	{
		PLpgSQL_stmt_return *new;

		new = palloc0(sizeof(PLpgSQL_stmt_return));
		new->cmd_type = PLPGSQL_STMT_RETURN;
		new->stmtid = ++function->nstatements;
		new->expr = NULL;
		new->retvarno = function->out_param_varno;

		function->action->body = lappend(function->action->body, new);
	}
}


/*
 * plpgsql_parser_setup		set up parser hooks for dynamic parameters
 *
 * Note: this routine, and the hook functions it prepares for, are logically
 * part of plpgsql parsing.  But they actually run during function execution,
 * when we are ready to evaluate a SQL query or expression that has not
 * previously been parsed and planned.
 */


/*
 * plpgsql_pre_column_ref		parser callback before parsing a ColumnRef
 */


/*
 * plpgsql_post_column_ref		parser callback after parsing a ColumnRef
 */


/*
 * plpgsql_param_ref		parser callback for ParamRefs ($n symbols)
 */


/*
 * resolve_column_ref		attempt to resolve a ColumnRef as a plpgsql var
 *
 * Returns the translated node structure, or NULL if name not found
 *
 * error_if_no_field tells whether to throw error or quietly return NULL if
 * we are able to match a record/row name but don't find a field name match.
 */


/*
 * Helper for columnref parsing: build a Param referencing a plpgsql datum,
 * and make sure that that datum is listed in the expression's paramnos.
 */



/* ----------
 * plpgsql_parse_word		The scanner calls this to postparse
 *				any single word that is not a reserved keyword.
 *
 * word1 is the downcased/dequoted identifier; it must be palloc'd in the
 * function's long-term memory context.
 *
 * yytxt is the original token text; we need this to check for quoting,
 * so that later checks for unreserved keywords work properly.
 *
 * We attempt to recognize the token as a variable only if lookup is true
 * and the plpgsql_IdentifierLookup context permits it.
 *
 * If recognized as a variable, fill in *wdatum and return true;
 * if not recognized, fill in *word and return false.
 * (Note: those two pointers actually point to members of the same union,
 * but for notational reasons we pass them separately.)
 * ----------
 */
bool
plpgsql_parse_word(char *word1, const char *yytxt, bool lookup,
				   PLwdatum *wdatum, PLword *word)
{
	PLpgSQL_nsitem *ns;

	/*
	 * We should not lookup variables in DECLARE sections.  In SQL
	 * expressions, there's no need to do so either --- lookup will happen
	 * when the expression is compiled.
	 */
	if (lookup && plpgsql_IdentifierLookup == IDENTIFIER_LOOKUP_NORMAL)
	{
		/*
		 * Do a lookup in the current namespace stack
		 */
		ns = plpgsql_ns_lookup(plpgsql_ns_top(), false,
							   word1, NULL, NULL,
							   NULL);

		if (ns != NULL)
		{
			switch (ns->itemtype)
			{
				case PLPGSQL_NSTYPE_VAR:
				case PLPGSQL_NSTYPE_REC:
					wdatum->datum = plpgsql_Datums[ns->itemno];
					wdatum->ident = word1;
					wdatum->quoted = (yytxt[0] == '"');
					wdatum->idents = NIL;
					return true;

				default:
					/* plpgsql_ns_lookup should never return anything else */
					elog(ERROR, "unrecognized plpgsql itemtype: %d",
						 ns->itemtype);
			}
		}
	}

	/*
	 * Nothing found - up to now it's a word without any special meaning for
	 * us.
	 */
	word->ident = word1;
	word->quoted = (yytxt[0] == '"');
	return false;
}


/* ----------
 * plpgsql_parse_dblword		Same lookup for two words
 *					separated by a dot.
 * ----------
 */
bool
plpgsql_parse_dblword(char *word1, char *word2,
					  PLwdatum *wdatum, PLcword *cword)
{
	PLpgSQL_nsitem *ns;
	List	   *idents;
	int			nnames;

	idents = list_make2(makeString(word1),
						makeString(word2));

	/*
	 * We should do nothing in DECLARE sections.  In SQL expressions, we
	 * really only need to make sure that RECFIELD datums are created when
	 * needed.  In all the cases handled by this function, returning a T_DATUM
	 * with a two-word idents string is the right thing.
	 */
	if (plpgsql_IdentifierLookup != IDENTIFIER_LOOKUP_DECLARE)
	{
		/*
		 * Do a lookup in the current namespace stack
		 */
		ns = plpgsql_ns_lookup(plpgsql_ns_top(), false,
							   word1, word2, NULL,
							   &nnames);
		if (ns != NULL)
		{
			switch (ns->itemtype)
			{
				case PLPGSQL_NSTYPE_VAR:
					/* Block-qualified reference to scalar variable. */
					wdatum->datum = plpgsql_Datums[ns->itemno];
					wdatum->ident = NULL;
					wdatum->quoted = false; /* not used */
					wdatum->idents = idents;
					return true;

				case PLPGSQL_NSTYPE_REC:
					if (nnames == 1)
					{
						/*
						 * First word is a record name, so second word could
						 * be a field in this record.  We build a RECFIELD
						 * datum whether it is or not --- any error will be
						 * detected later.
						 */
						PLpgSQL_rec *rec;
						PLpgSQL_recfield *new;

						rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]);
						new = plpgsql_build_recfield(rec, word2);

						wdatum->datum = (PLpgSQL_datum *) new;
					}
					else
					{
						/* Block-qualified reference to record variable. */
						wdatum->datum = plpgsql_Datums[ns->itemno];
					}
					wdatum->ident = NULL;
					wdatum->quoted = false; /* not used */
					wdatum->idents = idents;
					return true;

				default:
					break;
			}
		}
	}

	/* Nothing found */
	cword->idents = idents;
	return false;
}


/* ----------
 * plpgsql_parse_tripword		Same lookup for three words
 *					separated by dots.
 * ----------
 */
bool
plpgsql_parse_tripword(char *word1, char *word2, char *word3,
					   PLwdatum *wdatum, PLcword *cword)
{
	PLpgSQL_nsitem *ns;
	List	   *idents;
	int			nnames;

	/*
	 * We should do nothing in DECLARE sections.  In SQL expressions, we need
	 * to make sure that RECFIELD datums are created when needed, and we need
	 * to be careful about how many names are reported as belonging to the
	 * T_DATUM: the third word could be a sub-field reference, which we don't
	 * care about here.
	 */
	if (plpgsql_IdentifierLookup != IDENTIFIER_LOOKUP_DECLARE)
	{
		/*
		 * Do a lookup in the current namespace stack.  Must find a record
		 * reference, else ignore.
		 */
		ns = plpgsql_ns_lookup(plpgsql_ns_top(), false,
							   word1, word2, word3,
							   &nnames);
		if (ns != NULL)
		{
			switch (ns->itemtype)
			{
				case PLPGSQL_NSTYPE_REC:
					{
						PLpgSQL_rec *rec;
						PLpgSQL_recfield *new;

						rec = (PLpgSQL_rec *) (plpgsql_Datums[ns->itemno]);
						if (nnames == 1)
						{
							/*
							 * First word is a record name, so second word
							 * could be a field in this record (and the third,
							 * a sub-field).  We build a RECFIELD datum
							 * whether it is or not --- any error will be
							 * detected later.
							 */
							new = plpgsql_build_recfield(rec, word2);
							idents = list_make2(makeString(word1),
												makeString(word2));
						}
						else
						{
							/* Block-qualified reference to record variable. */
							new = plpgsql_build_recfield(rec, word3);
							idents = list_make3(makeString(word1),
												makeString(word2),
												makeString(word3));
						}
						wdatum->datum = (PLpgSQL_datum *) new;
						wdatum->ident = NULL;
						wdatum->quoted = false; /* not used */
						wdatum->idents = idents;
						return true;
					}

				default:
					break;
			}
		}
	}

	/* Nothing found */
	idents = list_make3(makeString(word1),
						makeString(word2),
						makeString(word3));
	cword->idents = idents;
	return false;
}


/* ----------
 * plpgsql_parse_wordtype	The scanner found word%TYPE. word should be
 *				a pre-existing variable name.
 *
 * Returns datatype struct.  Throws error if no match found for word.
 * ----------
 */
PLpgSQL_type *
plpgsql_parse_wordtype(char *ident)
{
	PLpgSQL_type *typ;

	typ = (PLpgSQL_type *) palloc0(sizeof(PLpgSQL_type));
	typ->typname = psprintf("%s%%TYPE", quote_identifier(ident));
	typ->origtypname = makeTypeName(ident);
	typ->origtypname->pct_type = true;
	typ->ttype = PLPGSQL_TTYPE_SCALAR;
	return typ;
}




/* ----------
 * plpgsql_parse_cwordtype		Same lookup for compositeword%TYPE
 *
 * Here, we allow either a block-qualified variable name, or a reference
 * to a column of some table.  (If we must throw error, we assume that the
 * latter case was intended.)
 * ----------
 */
PLpgSQL_type *
plpgsql_parse_cwordtype(List *idents)
{
	PLpgSQL_type *typ;

	typ = (PLpgSQL_type *) palloc0(sizeof(PLpgSQL_type));
	typ->typname = psprintf("%s%%TYPE", NameListToQuotedString(idents));
	typ->origtypname = makeTypeNameFromNameList(idents);
	typ->origtypname->pct_type = true;
	typ->ttype = PLPGSQL_TTYPE_SCALAR;
	return typ;
}



/* ----------
 * plpgsql_parse_wordrowtype		Scanner found word%ROWTYPE.
 *					So word must be a table name.
 * ----------
 */
PLpgSQL_type *
plpgsql_parse_wordrowtype(char *ident)
{
	PLpgSQL_type *typ;

	typ = (PLpgSQL_type *) palloc0(sizeof(PLpgSQL_type));
	typ->typname = psprintf("%s%%rowtype", quote_identifier(ident));
	typ->origtypname = makeTypeName(ident);
	typ->ttype = PLPGSQL_TTYPE_SCALAR;
	return typ;
}



/* ----------
 * plpgsql_parse_cwordrowtype		Scanner found compositeword%ROWTYPE.
 *			So word must be a namespace qualified table name.
 * ----------
 */
PLpgSQL_type *
plpgsql_parse_cwordrowtype(List *idents)
{
	PLpgSQL_type *typ;

	typ = (PLpgSQL_type *) palloc0(sizeof(PLpgSQL_type));
	typ->typname = psprintf("%s%%rowtype", NameListToQuotedString(idents));
	typ->origtypname = makeTypeNameFromNameList(idents);
	typ->ttype = PLPGSQL_TTYPE_SCALAR;
	return typ;
}



/*
 * plpgsql_build_variable - build a datum-array entry of a given
 * datatype
 *
 * The returned struct may be a PLpgSQL_var or PLpgSQL_rec
 * depending on the given datatype, and is allocated via
 * palloc.  The struct is automatically added to the current datum
 * array, and optionally to the current namespace.
 */
PLpgSQL_variable *
plpgsql_build_variable(const char *refname, int lineno, PLpgSQL_type *dtype,
					   bool add2namespace)
{
	PLpgSQL_variable *result;

	switch (dtype->ttype)
	{
		case PLPGSQL_TTYPE_SCALAR:
			{
				/* Ordinary scalar datatype */
				PLpgSQL_var *var;

				var = palloc0(sizeof(PLpgSQL_var));
				var->dtype = PLPGSQL_DTYPE_VAR;
				var->refname = pstrdup(refname);
				var->lineno = lineno;
				var->datatype = dtype;
				/* other fields are left as 0, might be changed by caller */

				/* preset to NULL */
				var->value = 0;
				var->isnull = true;
				var->freeval = false;

				plpgsql_adddatum((PLpgSQL_datum *) var);
				if (add2namespace)
					plpgsql_ns_additem(PLPGSQL_NSTYPE_VAR,
									   var->dno,
									   refname);
				result = (PLpgSQL_variable *) var;
				break;
			}
		case PLPGSQL_TTYPE_REC:
			{
				/* Composite type -- build a record variable */
				PLpgSQL_rec *rec;

				rec = plpgsql_build_record(refname, lineno,
										   dtype, dtype->typoid,
										   add2namespace);
				result = (PLpgSQL_variable *) rec;
				break;
			}
		case PLPGSQL_TTYPE_PSEUDO:
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("variable \"%s\" has pseudo-type %s",
							refname, format_type_be(dtype->typoid))));
			result = NULL;		/* keep compiler quiet */
			break;
		default:
			elog(ERROR, "unrecognized ttype: %d", dtype->ttype);
			result = NULL;		/* keep compiler quiet */
			break;
	}

	return result;
}

/*
 * Build empty named record variable, and optionally add it to namespace
 */
PLpgSQL_rec *
plpgsql_build_record(const char *refname, int lineno,
					 PLpgSQL_type *dtype, Oid rectypeid,
					 bool add2namespace)
{
	PLpgSQL_rec *rec;

	rec = palloc0(sizeof(PLpgSQL_rec));
	rec->dtype = PLPGSQL_DTYPE_REC;
	rec->refname = pstrdup(refname);
	rec->lineno = lineno;
	/* other fields are left as 0, might be changed by caller */
	rec->datatype = dtype;
	rec->rectypeid = rectypeid;
	rec->firstfield = -1;
	rec->erh = NULL;
	plpgsql_adddatum((PLpgSQL_datum *) rec);
	if (add2namespace)
		plpgsql_ns_additem(PLPGSQL_NSTYPE_REC, rec->dno, rec->refname);

	return rec;
}

/*
 * Build a row-variable data structure given the component variables.
 * Include a rowtupdesc, since we will need to materialize the row result.
 */
static PLpgSQL_row *
build_row_from_vars(PLpgSQL_variable **vars, int numvars)
{
	PLpgSQL_row *row;
	int			i;

	row = palloc0(sizeof(PLpgSQL_row));
	row->dtype = PLPGSQL_DTYPE_ROW;
	row->refname = "(unnamed row)";
	row->lineno = -1;
	row->rowtupdesc = CreateTemplateTupleDesc(numvars);
	row->nfields = numvars;
	row->fieldnames = palloc(numvars * sizeof(char *));
	row->varnos = palloc(numvars * sizeof(int));

	for (i = 0; i < numvars; i++)
	{
		PLpgSQL_variable *var = vars[i];
		Oid			typoid;
		int32		typmod;
		Oid			typcoll;

		/* Member vars of a row should never be const */
		Assert(!var->isconst);

		switch (var->dtype)
		{
			case PLPGSQL_DTYPE_VAR:
			case PLPGSQL_DTYPE_PROMISE:
				typoid = ((PLpgSQL_var *) var)->datatype->typoid;
				typmod = ((PLpgSQL_var *) var)->datatype->atttypmod;
				typcoll = ((PLpgSQL_var *) var)->datatype->collation;
				break;

			case PLPGSQL_DTYPE_REC:
				/* shouldn't need to revalidate rectypeid already... */
				typoid = ((PLpgSQL_rec *) var)->rectypeid;
				typmod = -1;	/* don't know typmod, if it's used at all */
				typcoll = InvalidOid;	/* composite types have no collation */
				break;

			default:
				elog(ERROR, "unrecognized dtype: %d", var->dtype);
				typoid = InvalidOid;	/* keep compiler quiet */
				typmod = 0;
				typcoll = InvalidOid;
				break;
		}

		row->fieldnames[i] = var->refname;
		row->varnos[i] = var->dno;

		TupleDescInitEntry(row->rowtupdesc, i + 1,
						   var->refname,
						   typoid, typmod,
						   0);
		TupleDescInitEntryCollation(row->rowtupdesc, i + 1, typcoll);
	}

	return row;
}

/*
 * Build a RECFIELD datum for the named field of the specified record variable
 *
 * If there's already such a datum, just return it; we don't need duplicates.
 */
PLpgSQL_recfield *
plpgsql_build_recfield(PLpgSQL_rec *rec, const char *fldname)
{
	PLpgSQL_recfield *recfield;
	int			i;

	/* search for an existing datum referencing this field */
	i = rec->firstfield;
	while (i >= 0)
	{
		PLpgSQL_recfield *fld = (PLpgSQL_recfield *) plpgsql_Datums[i];

		Assert(fld->dtype == PLPGSQL_DTYPE_RECFIELD &&
			   fld->recparentno == rec->dno);
		if (strcmp(fld->fieldname, fldname) == 0)
			return fld;
		i = fld->nextfield;
	}

	/* nope, so make a new one */
	recfield = palloc0(sizeof(PLpgSQL_recfield));
	recfield->dtype = PLPGSQL_DTYPE_RECFIELD;
	recfield->fieldname = pstrdup(fldname);
	recfield->recparentno = rec->dno;
	recfield->rectupledescid = INVALID_TUPLEDESC_IDENTIFIER;

	plpgsql_adddatum((PLpgSQL_datum *) recfield);

	/* now we can link it into the parent's chain */
	recfield->nextfield = rec->firstfield;
	rec->firstfield = recfield->dno;

	return recfield;
}

/*
 * plpgsql_build_datatype
 *		Build PLpgSQL_type struct given type OID, typmod, collation,
 *		and type's parsed name.
 *
 * If collation is not InvalidOid then it overrides the type's default
 * collation.  But collation is ignored if the datatype is non-collatable.
 *
 * origtypname is the parsed form of what the user wrote as the type name.
 * It can be NULL if the type could not be a composite type, or if it was
 * identified by OID to begin with (e.g., it's a function argument type).
 */
PLpgSQL_type *
plpgsql_build_datatype(Oid typeOid, int32 typmod,
					   Oid collation, TypeName *origtypname)
{
	HeapTuple	typeTup;
	PLpgSQL_type *typ;

	typeTup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typeOid));
	if (!HeapTupleIsValid(typeTup))
		elog(ERROR, "cache lookup failed for type %u", typeOid);

	typ = build_datatype(typeTup, typmod, collation, origtypname);

	ReleaseSysCache(typeTup);

	return typ;
}

/*
 * Utility subroutine to make a PLpgSQL_type struct given a pg_type entry
 * and additional details (see comments for plpgsql_build_datatype).
 */
static PLpgSQL_type *
build_datatype(HeapTuple typeTup, int32 typmod,
			   Oid collation, TypeName *origtypname)
{
	Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
	PLpgSQL_type *typ;

	if (!typeStruct->typisdefined)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" is only a shell",
						NameStr(typeStruct->typname))));

	typ = (PLpgSQL_type *) palloc(sizeof(PLpgSQL_type));

	typ->typname = pstrdup(NameStr(typeStruct->typname));
	typ->typoid = typeStruct->oid;
	switch (typeStruct->typtype)
	{
		case TYPTYPE_BASE:
		case TYPTYPE_ENUM:
		case TYPTYPE_RANGE:
		case TYPTYPE_MULTIRANGE:
			typ->ttype = PLPGSQL_TTYPE_SCALAR;
			break;
		case TYPTYPE_COMPOSITE:
			typ->ttype = PLPGSQL_TTYPE_REC;
			break;
		case TYPTYPE_DOMAIN:
			if (type_is_rowtype(typeStruct->typbasetype))
				typ->ttype = PLPGSQL_TTYPE_REC;
			else
				typ->ttype = PLPGSQL_TTYPE_SCALAR;
			break;
		case TYPTYPE_PSEUDO:
			if (typ->typoid == RECORDOID)
				typ->ttype = PLPGSQL_TTYPE_REC;
			else
				typ->ttype = PLPGSQL_TTYPE_PSEUDO;
			break;
		default:
			elog(ERROR, "unrecognized typtype: %d",
				 (int) typeStruct->typtype);
			break;
	}
	typ->typlen = typeStruct->typlen;
	typ->typbyval = typeStruct->typbyval;
	typ->typtype = typeStruct->typtype;
	typ->collation = typeStruct->typcollation;
	if (OidIsValid(collation) && OidIsValid(typ->collation))
		typ->collation = collation;
	/* Detect if type is true array, or domain thereof */
	/* NB: this is only used to decide whether to apply expand_array */
	if (typeStruct->typtype == TYPTYPE_BASE)
	{
		/*
		 * This test should include what get_element_type() checks.  We also
		 * disallow non-toastable array types (i.e. oidvector and int2vector).
		 */
		typ->typisarray = (IsTrueArrayType(typeStruct) &&
						   typeStruct->typstorage != TYPSTORAGE_PLAIN);
	}
	else if (typeStruct->typtype == TYPTYPE_DOMAIN)
	{
		/* we can short-circuit looking up base types if it's not varlena */
		typ->typisarray = (typeStruct->typlen == -1 &&
						   typeStruct->typstorage != TYPSTORAGE_PLAIN &&
						   OidIsValid(get_base_element_type(typeStruct->typbasetype)));
	}
	else
		typ->typisarray = false;
	typ->atttypmod = typmod;

	/*
	 * If it's a named composite type (or domain over one), find the typcache
	 * entry and record the current tupdesc ID, so we can detect changes
	 * (including drops).  We don't currently support on-the-fly replacement
	 * of non-composite types, else we might want to do this for them too.
	 */
    // CHANGED: Not needed, and lookup_type_cache introduces unnecessary dependencies
	/*if (typ->ttype == PLPGSQL_TTYPE_REC && typ->typoid != RECORDOID)
	{
		TypeCacheEntry *typentry;

		typentry = lookup_type_cache(typ->typoid,
									 TYPECACHE_TUPDESC |
									 TYPECACHE_DOMAIN_BASE_INFO);
		if (typentry->typtype == TYPTYPE_DOMAIN)
			typentry = lookup_type_cache(typentry->domainBaseType,
										 TYPECACHE_TUPDESC);
		if (typentry->tupDesc == NULL)
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("type %s is not composite",
							format_type_be(typ->typoid))));

		typ->origtypname = origtypname;
		typ->tcache = typentry;
		typ->tupdesc_id = typentry->tupDesc_identifier;
	}
	else*/
	{
		typ->origtypname = NULL;
		typ->tcache = NULL;
		typ->tupdesc_id = 0;
	}

	return typ;
}


/*
 * Build an array type for the element type specified as argument.
 */
PLpgSQL_type *
plpgsql_build_datatype_arrayof(PLpgSQL_type *dtype)
{
	Oid			array_typeid;

	/*
	 * If it's already an array type, use it as-is: Postgres doesn't do nested
	 * arrays.
	 */
	if (dtype->typisarray)
		return dtype;

	array_typeid = get_array_type(dtype->typoid);
	if (!OidIsValid(array_typeid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("could not find array type for data type %s",
						format_type_be(dtype->typoid))));

	/* Note we inherit typmod and collation, if any, from the element type */
	return plpgsql_build_datatype(array_typeid, dtype->atttypmod,
								  dtype->collation, NULL);
}

/*
 *	plpgsql_recognize_err_condition
 *		Check condition name and translate it to SQLSTATE.
 *
 * Note: there are some cases where the same condition name has multiple
 * entries in the table.  We arbitrarily return the first match.
 */
int
plpgsql_recognize_err_condition(const char *condname, bool allow_sqlstate)
{
	int			i;

	if (allow_sqlstate)
	{
		if (strlen(condname) == 5 &&
			strspn(condname, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ") == 5)
			return MAKE_SQLSTATE(condname[0],
								 condname[1],
								 condname[2],
								 condname[3],
								 condname[4]);
	}

	for (i = 0; exception_label_map[i].label != NULL; i++)
	{
		if (strcmp(condname, exception_label_map[i].label) == 0)
			return exception_label_map[i].sqlerrstate;
	}

	ereport(ERROR,
			(errcode(ERRCODE_UNDEFINED_OBJECT),
			 errmsg("unrecognized exception condition \"%s\"",
					condname)));
	return 0;					/* keep compiler quiet */
}

/*
 * plpgsql_parse_err_condition
 *		Generate PLpgSQL_condition entry(s) for an exception condition name
 *
 * This has to be able to return a list because there are some duplicate
 * names in the table of error code names.
 */
PLpgSQL_condition *
plpgsql_parse_err_condition(char *condname)
{
	int			i;
	PLpgSQL_condition *new;
	PLpgSQL_condition *prev;

	/*
	 * XXX Eventually we will want to look for user-defined exception names
	 * here.
	 */

	if (strcmp(condname, "others") == 0)
	{
		new = palloc(sizeof(PLpgSQL_condition));
		new->sqlerrstate = PLPGSQL_OTHERS;
		new->condname = condname;
		new->next = NULL;
		return new;
	}

	prev = NULL;
	for (i = 0; exception_label_map[i].label != NULL; i++)
	{
		if (strcmp(condname, exception_label_map[i].label) == 0)
		{
			new = palloc(sizeof(PLpgSQL_condition));
			new->sqlerrstate = exception_label_map[i].sqlerrstate;
			new->condname = condname;
			new->next = prev;
			prev = new;
		}
	}

	if (!prev)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("unrecognized exception condition \"%s\"",
						condname)));

	return prev;
}

/* ----------
 * plpgsql_start_datums			Initialize datum list at compile startup.
 * ----------
 */
void
plpgsql_start_datums(void)
{
	datums_alloc = 128;
	plpgsql_nDatums = 0;
	/* This is short-lived, so needn't allocate in function's cxt */
	plpgsql_Datums = MemoryContextAlloc(plpgsql_compile_tmp_cxt,
										sizeof(PLpgSQL_datum *) * datums_alloc);
	/* datums_last tracks what's been seen by plpgsql_add_initdatums() */
	datums_last = 0;
}

/* ----------
 * plpgsql_adddatum			Add a variable, record or row
 *					to the compiler's datum list.
 * ----------
 */
void
plpgsql_adddatum(PLpgSQL_datum *newdatum)
{
	if (plpgsql_nDatums == datums_alloc)
	{
		datums_alloc *= 2;
		plpgsql_Datums = repalloc(plpgsql_Datums, sizeof(PLpgSQL_datum *) * datums_alloc);
	}

	newdatum->dno = plpgsql_nDatums;
	plpgsql_Datums[plpgsql_nDatums++] = newdatum;
}

/* ----------
 * plpgsql_finish_datums	Copy completed datum info into function struct.
 * ----------
 */
void
plpgsql_finish_datums(PLpgSQL_function *function)
{
	Size		copiable_size = 0;
	int			i;

	function->ndatums = plpgsql_nDatums;
	function->datums = palloc(sizeof(PLpgSQL_datum *) * plpgsql_nDatums);
	for (i = 0; i < plpgsql_nDatums; i++)
	{
		function->datums[i] = plpgsql_Datums[i];

		/* This must agree with copy_plpgsql_datums on what is copiable */
		switch (function->datums[i]->dtype)
		{
			case PLPGSQL_DTYPE_VAR:
			case PLPGSQL_DTYPE_PROMISE:
				copiable_size += MAXALIGN(sizeof(PLpgSQL_var));
				break;
			case PLPGSQL_DTYPE_REC:
				copiable_size += MAXALIGN(sizeof(PLpgSQL_rec));
				break;
			default:
				break;
		}
	}
	function->copiable_size = copiable_size;
}


/* ----------
 * plpgsql_add_initdatums		Make an array of the datum numbers of
 *					all the initializable datums created since the last call
 *					to this function.
 *
 * If varnos is NULL, we just forget any datum entries created since the
 * last call.
 *
 * This is used around a DECLARE section to create a list of the datums
 * that have to be initialized at block entry.  Note that datums can also
 * be created elsewhere than DECLARE, eg by a FOR-loop, but it is then
 * the responsibility of special-purpose code to initialize them.
 * ----------
 */
int
plpgsql_add_initdatums(int **varnos)
{
	int			i;
	int			n = 0;

	/*
	 * The set of dtypes recognized here must match what exec_stmt_block()
	 * cares about (re)initializing at block entry.
	 */
	for (i = datums_last; i < plpgsql_nDatums; i++)
	{
		switch (plpgsql_Datums[i]->dtype)
		{
			case PLPGSQL_DTYPE_VAR:
			case PLPGSQL_DTYPE_REC:
				n++;
				break;

			default:
				break;
		}
	}

	if (varnos != NULL)
	{
		if (n > 0)
		{
			*varnos = (int *) palloc(sizeof(int) * n);

			n = 0;
			for (i = datums_last; i < plpgsql_nDatums; i++)
			{
				switch (plpgsql_Datums[i]->dtype)
				{
					case PLPGSQL_DTYPE_VAR:
					case PLPGSQL_DTYPE_REC:
						(*varnos)[n++] = plpgsql_Datums[i]->dno;

					default:
						break;
				}
			}
		}
		else
			*varnos = NULL;
	}

	datums_last = plpgsql_nDatums;
	return n;
}