diff --git a/contrib/cube/cubedata.h b/contrib/cube/cubedata.h
index fd0c26a..01e0818 100644
--- a/contrib/cube/cubedata.h
+++ b/contrib/cube/cubedata.h
@@ -6,7 +6,7 @@ typedef struct NDBOX
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	unsigned int dim;
-	double		x[1];
+	double		x[FLEXIBLE_ARRAY_MEMBER];
 } NDBOX;
 
 #define DatumGetNDBOX(x)	((NDBOX*)DatumGetPointer(x))
diff --git a/contrib/intarray/_int.h b/contrib/intarray/_int.h
index 56aa23c..c35e862 100644
--- a/contrib/intarray/_int.h
+++ b/contrib/intarray/_int.h
@@ -72,7 +72,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		flag;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } GISTTYPE;
 
 #define ALLISTRUE		0x04
@@ -132,7 +132,7 @@ typedef struct QUERYTYPE
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		size;			/* number of ITEMs */
-	ITEM		items[1];		/* variable length array */
+	ITEM		items[FLEXIBLE_ARRAY_MEMBER];
 } QUERYTYPE;
 
 #define HDRSIZEQT	offsetof(QUERYTYPE, items)
diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index 563970a..bf25f4c 100644
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -9,7 +9,7 @@
 typedef struct
 {
 	uint16		len;
-	char		name[1];
+	char		name[FLEXIBLE_ARRAY_MEMBER];
 } ltree_level;
 
 #define LEVEL_HDRSIZE	(offsetof(ltree_level,name))
@@ -19,7 +19,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	uint16		numlevel;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } ltree;
 
 #define LTREE_HDRSIZE	MAXALIGN( offsetof(ltree, data) )
@@ -33,7 +33,7 @@ typedef struct
 	int32		val;
 	uint16		len;
 	uint8		flag;
-	char		name[1];
+	char		name[FLEXIBLE_ARRAY_MEMBER];
 } lquery_variant;
 
 #define LVAR_HDRSIZE   MAXALIGN(offsetof(lquery_variant, name))
@@ -50,7 +50,7 @@ typedef struct
 	uint16		numvar;
 	uint16		low;
 	uint16		high;
-	char		variants[1];
+	char		variants[FLEXIBLE_ARRAY_MEMBER];
 } lquery_level;
 
 #define LQL_HDRSIZE MAXALIGN( offsetof(lquery_level,variants) )
@@ -71,7 +71,7 @@ typedef struct
 	uint16		numlevel;
 	uint16		firstgood;
 	uint16		flag;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } lquery;
 
 #define LQUERY_HDRSIZE	 MAXALIGN( offsetof(lquery, data) )
@@ -106,7 +106,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		size;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } ltxtquery;
 
 #define HDRSIZEQT		MAXALIGN(VARHDRSZ + sizeof(int32))
@@ -205,7 +205,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	uint32		flag;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } ltree_gist;
 
 #define LTG_ONENODE 0x01
diff --git a/contrib/pg_trgm/trgm.h b/contrib/pg_trgm/trgm.h
index ed649b8..f030558 100644
--- a/contrib/pg_trgm/trgm.h
+++ b/contrib/pg_trgm/trgm.h
@@ -63,7 +63,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	uint8		flag;
-	char		data[1];
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } TRGM;
 
 #define TRGMHDRSIZE		  (VARHDRSZ + sizeof(uint8))
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index f48c0bc..4323184 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -1066,7 +1066,7 @@ static bool MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
 		 */
 		effective_nargs = Max(pronargs, nargs);
 		newResult = (FuncCandidateList)
-			palloc(sizeof(struct _FuncCandidateList) - sizeof(Oid)
+			palloc(offsetof(struct _FuncCandidateList, args)
 				   + effective_nargs * sizeof(Oid));
 		newResult->pathpos = pathpos;
 		newResult->oid = HeapTupleGetOid(proctup);
@@ -1580,7 +1580,7 @@ static bool MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
 	 * separate palloc for each operator, but profiling revealed that the
 	 * pallocs used an unreasonably large fraction of parsing time.
 	 */
-#define SPACE_PER_OP MAXALIGN(sizeof(struct _FuncCandidateList) + sizeof(Oid))
+#define SPACE_PER_OP MAXALIGN(offsetof(struct _FuncCandidateList, args) + sizeof(Oid)) // XXX
 
 	if (catlist->n_members > 0)
 		resultSpace = palloc(catlist->n_members * SPACE_PER_OP);
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 62208eb..ca16a4d 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -383,10 +383,9 @@ static ParamListInfo EvaluateParams(PreparedStatement *pstmt, List *params,
 	/* Prepare the expressions for execution */
 	exprstates = (List *) ExecPrepareExpr((Expr *) params, estate);
 
-	/* sizeof(ParamListInfoData) includes the first array element */
 	paramLI = (ParamListInfo)
-		palloc(sizeof(ParamListInfoData) +
-			   (num_params - 1) * sizeof(ParamExternData));
+		palloc(offsetof(ParamListInfoData, params) +
+			   num_params * sizeof(ParamExternData));
 	/* we have static list of params, so no hooks needed */
 	paramLI->paramFetch = NULL;
 	paramLI->paramFetchArg = NULL;
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index dbb4805..034a17e 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -888,9 +888,8 @@ static Datum postquel_get_single_result(TupleTableSlot *slot,
 
 		if (fcache->paramLI == NULL)
 		{
-			/* sizeof(ParamListInfoData) includes the first array element */
-			paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
-									  (nargs - 1) * sizeof(ParamExternData));
+			paramLI = (ParamListInfo) palloc(offsetof(ParamListInfoData, params) +
+											 nargs * sizeof(ParamExternData));
 			/* we have static list of params, so no hooks needed */
 			paramLI->paramFetch = NULL;
 			paramLI->paramFetchArg = NULL;
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index ca0d05d..df052d7 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2216,9 +2216,8 @@ static void _SPI_cursor_operation(Portal portal,
 	{
 		int			i;
 
-		/* sizeof(ParamListInfoData) includes the first array element */
-		paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
-									  (nargs - 1) * sizeof(ParamExternData));
+		paramLI = (ParamListInfo) palloc(offsetof(ParamListInfoData, params) +
+										 nargs * sizeof(ParamExternData));
 		/* we have static list of params, so no hooks needed */
 		paramLI->paramFetch = NULL;
 		paramLI->paramFetchArg = NULL;
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index 601659b..6fe3744 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -40,9 +40,8 @@
 	if (from == NULL || from->numParams <= 0)
 		return NULL;
 
-	/* sizeof(ParamListInfoData) includes the first array element */
-	size = sizeof(ParamListInfoData) +
-		(from->numParams - 1) * sizeof(ParamExternData);
+	size = offsetof(ParamListInfoData, params) +
+		from->numParams * sizeof(ParamExternData);
 
 	retval = (ParamListInfo) palloc(size);
 	retval->paramFetch = NULL;
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index f078303..47b1a80 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1562,9 +1562,8 @@
 	{
 		int			paramno;
 
-		/* sizeof(ParamListInfoData) includes the first array element */
-		params = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
-								  (numParams - 1) * sizeof(ParamExternData));
+		params = (ParamListInfo) palloc(offsetof(ParamListInfoData, params) +
+								  numParams * sizeof(ParamExternData));
 		/* we have static list of params, so no hooks needed */
 		params->paramFetch = NULL;
 		params->paramFetchArg = NULL;
diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index 356e8eb..74f83c2 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -22,7 +22,7 @@
 typedef struct SimpleStringListCell
 {
 	struct SimpleStringListCell *next;
-	char		val[1];			/* VARIABLE LENGTH FIELD */
+	char		val[FLEXIBLE_ARRAY_MEMBER];
 } SimpleStringListCell;
 
 typedef struct SimpleStringList
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index cae6dbc..72106ab 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -31,7 +31,7 @@ typedef struct
 {
 	BlockNumber prev;
 	uint32		freespace;
-	char		tupledata[1];
+	char		tupledata[FLEXIBLE_ARRAY_MEMBER];
 } GISTNodeBufferPage;
 
 #define BUFFER_PAGE_DATA_OFFSET MAXALIGN(offsetof(GISTNodeBufferPage, tupledata))
@@ -129,7 +129,7 @@ typedef struct GISTSearchTreeItem
 	RBNode		rbnode;			/* this is an RBTree item */
 	GISTSearchItem *head;		/* first chain member */
 	GISTSearchItem *lastHeap;	/* last heap-tuple member, if any */
-	double		distances[1];	/* array with numberOfOrderBys entries */
+	double		distances[FLEXIBLE_ARRAY_MEMBER];	/* array with numberOfOrderBys entries */
 } GISTSearchTreeItem;
 
 #define GSTIHDRSZ offsetof(GISTSearchTreeItem, distances)
diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h
index e58eae5..2e2ab05 100644
--- a/src/include/access/heapam_xlog.h
+++ b/src/include/access/heapam_xlog.h
@@ -122,7 +122,7 @@ typedef struct xl_heap_multi_insert
 	BlockNumber blkno;
 	bool		all_visible_cleared;
 	uint16		ntuples;
-	OffsetNumber offsets[1];
+	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
 
 	/* TUPLE DATA (xl_multi_insert_tuples) FOLLOW AT END OF STRUCT */
 } xl_heap_multi_insert;
diff --git a/src/include/access/htup_details.h b/src/include/access/htup_details.h
index cd01ecd..2856986 100644
--- a/src/include/access/htup_details.h
+++ b/src/include/access/htup_details.h
@@ -149,7 +149,7 @@ struct HeapTupleHeaderData
 
 	/* ^ - 23 bytes - ^ */
 
-	bits8		t_bits[1];		/* bitmap of NULLs -- VARIABLE LENGTH */
+	bits8		t_bits[FLEXIBLE_ARRAY_MEMBER];		/* bitmap of NULLs */
 
 	/* MORE DATA FOLLOWS AT END OF STRUCT */
 };
@@ -523,7 +523,7 @@ struct MinimalTupleData
 
 	/* ^ - 23 bytes - ^ */
 
-	bits8		t_bits[1];		/* bitmap of NULLs -- VARIABLE LENGTH */
+	bits8		t_bits[FLEXIBLE_ARRAY_MEMBER];		/* bitmap of NULLs */
 
 	/* MORE DATA FOLLOWS AT END OF STRUCT */
 };
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 835f6ac..3b39ee6 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -116,7 +116,7 @@ typedef struct xl_xact_assignment
 {
 	TransactionId xtop;			/* assigned XID's top-level XID */
 	int			nsubxacts;		/* number of subtransaction XIDs */
-	TransactionId xsub[1];		/* assigned subxids */
+	TransactionId xsub[FLEXIBLE_ARRAY_MEMBER];		/* assigned subxids */
 } xl_xact_assignment;
 
 #define MinSizeOfXactAssignment offsetof(xl_xact_assignment, xsub)
@@ -126,7 +126,7 @@ typedef struct xl_xact_commit_compact
 	TimestampTz xact_time;		/* time of commit */
 	int			nsubxacts;		/* number of subtransaction XIDs */
 	/* ARRAY OF COMMITTED SUBTRANSACTION XIDs FOLLOWS */
-	TransactionId subxacts[1];	/* VARIABLE LENGTH ARRAY */
+	TransactionId subxacts[FLEXIBLE_ARRAY_MEMBER];
 } xl_xact_commit_compact;
 
 #define MinSizeOfXactCommitCompact offsetof(xl_xact_commit_compact, subxacts)
@@ -141,7 +141,7 @@ typedef struct xl_xact_commit
 	Oid			dbId;			/* MyDatabaseId */
 	Oid			tsId;			/* MyDatabaseTableSpace */
 	/* Array of RelFileNode(s) to drop at commit */
-	RelFileNode xnodes[1];		/* VARIABLE LENGTH ARRAY */
+	RelFileNode xnodes[FLEXIBLE_ARRAY_MEMBER];
 	/* ARRAY OF COMMITTED SUBTRANSACTION XIDs FOLLOWS */
 	/* ARRAY OF SHARED INVALIDATION MESSAGES FOLLOWS */
 } xl_xact_commit;
@@ -169,7 +169,7 @@ typedef struct xl_xact_abort
 	int			nrels;			/* number of RelFileNodes */
 	int			nsubxacts;		/* number of subtransaction XIDs */
 	/* Array of RelFileNode(s) to drop at abort */
-	RelFileNode xnodes[1];		/* VARIABLE LENGTH ARRAY */
+	RelFileNode xnodes[FLEXIBLE_ARRAY_MEMBER];
 	/* ARRAY OF ABORTED SUBTRANSACTION XIDs FOLLOWS */
 } xl_xact_abort;
 
diff --git a/src/include/c.h b/src/include/c.h
index ca7ff86..f533074 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -394,7 +394,7 @@ typedef struct
 struct varlena
 {
 	char		vl_len_[4];		/* Do not touch this field directly! */
-	char		vl_dat[1];
+	char		vl_dat[FLEXIBLE_ARRAY_MEMBER];
 };
 
 #define VARHDRSZ		((int32) sizeof(int32))
@@ -427,8 +427,8 @@ typedef struct
 	Oid			elemtype;
 	int			dim1;
 	int			lbound1;
-	int16		values[1];		/* VARIABLE LENGTH ARRAY */
-} int2vector;					/* VARIABLE LENGTH STRUCT */
+	int16		values[FLEXIBLE_ARRAY_MEMBER];
+} int2vector;
 
 typedef struct
 {
@@ -438,8 +438,8 @@ typedef struct
 	Oid			elemtype;
 	int			dim1;
 	int			lbound1;
-	Oid			values[1];		/* VARIABLE LENGTH ARRAY */
-} oidvector;					/* VARIABLE LENGTH STRUCT */
+	Oid			values[FLEXIBLE_ARRAY_MEMBER];
+} oidvector;
 
 /*
  * Representation of a Name: effectively just a C string, but null-padded to
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 4fadc74..4db3d42 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -34,8 +34,8 @@ typedef struct _FuncCandidateList
 	int			nvargs;			/* number of args to become variadic array */
 	int			ndargs;			/* number of defaulted args */
 	int		   *argnumbers;		/* args' positional indexes, if named call */
-	Oid			args[1];		/* arg types --- VARIABLE LENGTH ARRAY */
-}	*FuncCandidateList;	/* VARIABLE LENGTH STRUCT */
+	Oid			args[FLEXIBLE_ARRAY_MEMBER];		/* arg types */
+}	*FuncCandidateList;
 
 /*
  *	Structure for xxxOverrideSearchPath functions
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 942b883..ab7a56c 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -25,7 +25,7 @@ typedef struct xl_dbase_create_rec_old
 {
 	/* Records copying of a single subdirectory incl. contents */
 	Oid			db_id;
-	char		src_path[1];	/* VARIABLE LENGTH STRING */
+	char		src_path[FLEXIBLE_ARRAY_MEMBER];
 	/* dst_path follows src_path */
 }	xl_dbase_create_rec_old;
 
@@ -33,7 +33,7 @@ typedef struct xl_dbase_drop_rec_old
 {
 	/* Records dropping of a single subdirectory incl. contents */
 	Oid			db_id;
-	char		dir_path[1];	/* VARIABLE LENGTH STRING */
+	char		dir_path[FLEXIBLE_ARRAY_MEMBER];
 }	xl_dbase_drop_rec_old;
 
 typedef struct xl_dbase_create_rec
diff --git a/src/include/commands/tablespace.h b/src/include/commands/tablespace.h
index 1e396a8..0ec1869 100644
--- a/src/include/commands/tablespace.h
+++ b/src/include/commands/tablespace.h
@@ -24,7 +24,7 @@
 typedef struct xl_tblspc_create_rec
 {
 	Oid			ts_id;
-	char		ts_path[1];		/* VARIABLE LENGTH STRING */
+	char		ts_path[FLEXIBLE_ARRAY_MEMBER];
 } xl_tblspc_create_rec;
 
 typedef struct xl_tblspc_drop_rec
diff --git a/src/include/nodes/bitmapset.h b/src/include/nodes/bitmapset.h
index 2a4b41d..6d51fa8 100644
--- a/src/include/nodes/bitmapset.h
+++ b/src/include/nodes/bitmapset.h
@@ -32,8 +32,8 @@ typedef int32 signedbitmapword; /* must be the matching signed type */
 typedef struct Bitmapset
 {
 	int			nwords;			/* number of words in array */
-	bitmapword	words[1];		/* really [nwords] */
-} Bitmapset;					/* VARIABLE LENGTH STRUCT */
+	bitmapword	words[FLEXIBLE_ARRAY_MEMBER];		/* really [nwords] */
+} Bitmapset;
 
 
 /* result of bms_subset_compare */
diff --git a/src/include/nodes/params.h b/src/include/nodes/params.h
index 61bdff0..7a71e45 100644
--- a/src/include/nodes/params.h
+++ b/src/include/nodes/params.h
@@ -71,7 +71,7 @@ typedef struct ParamListInfoData
 	ParserSetupHook parserSetup;	/* parser setup hook */
 	void	   *parserSetupArg;
 	int			numParams;		/* number of ParamExternDatas following */
-	ParamExternData params[1];	/* VARIABLE LENGTH ARRAY */
+	ParamExternData params[FLEXIBLE_ARRAY_MEMBER];
 }	ParamListInfoData;
 
 
diff --git a/src/include/nodes/tidbitmap.h b/src/include/nodes/tidbitmap.h
index 70c0025..071b35b 100644
--- a/src/include/nodes/tidbitmap.h
+++ b/src/include/nodes/tidbitmap.h
@@ -41,8 +41,8 @@ typedef struct
 	int			ntuples;		/* -1 indicates lossy result */
 	bool		recheck;		/* should the tuples be rechecked? */
 	/* Note: recheck is always true if ntuples < 0 */
-	OffsetNumber offsets[1];	/* VARIABLE LENGTH ARRAY */
-} TBMIterateResult;				/* VARIABLE LENGTH STRUCT */
+	OffsetNumber offsets[FLEXIBLE_ARRAY_MEMBER];
+} TBMIterateResult;
 
 /* function prototypes in nodes/tidbitmap.c */
 
diff --git a/src/include/postgres.h b/src/include/postgres.h
index f9c5527..340c8ef 100644
--- a/src/include/postgres.h
+++ b/src/include/postgres.h
@@ -86,27 +86,27 @@ typedef union
 	struct						/* Normal varlena (4-byte length) */
 	{
 		uint32		va_header;
-		char		va_data[1];
+		char		va_data[FLEXIBLE_ARRAY_MEMBER];
 	}			va_4byte;
 	struct						/* Compressed-in-line format */
 	{
 		uint32		va_header;
 		uint32		va_rawsize; /* Original data size (excludes header) */
-		char		va_data[1]; /* Compressed data */
+		char		va_data[FLEXIBLE_ARRAY_MEMBER]; /* Compressed data */
 	}			va_compressed;
 } varattrib_4b;
 
 typedef struct
 {
 	uint8		va_header;
-	char		va_data[1];		/* Data begins here */
+	char		va_data[FLEXIBLE_ARRAY_MEMBER];		/* Data begins here */
 } varattrib_1b;
 
 typedef struct
 {
 	uint8		va_header;		/* Always 0x80 or 0x01 */
 	uint8		va_len_1be;		/* Physical length of datum */
-	char		va_data[1];		/* Data (for now always a TOAST pointer) */
+	char		va_data[FLEXIBLE_ARRAY_MEMBER];		/* Data (for now always a TOAST pointer) */
 } varattrib_1b_e;
 
 /*
diff --git a/src/include/postmaster/syslogger.h b/src/include/postmaster/syslogger.h
index 5a3ecde..17b8970 100644
--- a/src/include/postmaster/syslogger.h
+++ b/src/include/postmaster/syslogger.h
@@ -48,7 +48,7 @@ typedef struct
 	int32		pid;			/* writer's pid */
 	char		is_last;		/* last chunk of message? 't' or 'f' ('T' or
 								 * 'F' for CSV case) */
-	char		data[1];		/* data payload starts here */
+	char		data[FLEXIBLE_ARRAY_MEMBER];		/* data payload starts here */
 } PipeProtoHeader;
 
 typedef union
diff --git a/src/include/replication/walsender_private.h b/src/include/replication/walsender_private.h
index 7eaa21b..67c8ccd 100644
--- a/src/include/replication/walsender_private.h
+++ b/src/include/replication/walsender_private.h
@@ -88,7 +88,7 @@ typedef struct
 	 */
 	bool		sync_standbys_defined;
 
-	WalSnd		walsnds[1];		/* VARIABLE LENGTH ARRAY */
+	WalSnd		walsnds[FLEXIBLE_ARRAY_MEMBER];
 } WalSndCtlData;
 
 extern WalSndCtlData *WalSndCtl;
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index b9ee7c2..ccb1c90 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -156,7 +156,7 @@ typedef struct PageHeaderData
 	LocationIndex pd_special;	/* offset to start of special space */
 	uint16		pd_pagesize_version;
 	TransactionId pd_prune_xid; /* oldest prunable XID, or zero if none */
-	ItemIdData	pd_linp[1];		/* beginning of line pointer array */
+	ItemIdData	pd_linp[FLEXIBLE_ARRAY_MEMBER];		/* beginning of line pointer array */
 } PageHeaderData;
 
 typedef PageHeaderData *PageHeader;
diff --git a/src/include/storage/fsm_internals.h b/src/include/storage/fsm_internals.h
index 0d86e1d..75ba781 100644
--- a/src/include/storage/fsm_internals.h
+++ b/src/include/storage/fsm_internals.h
@@ -39,7 +39,7 @@ typedef struct
 	 * NonLeafNodesPerPage elements are upper nodes, and the following
 	 * LeafNodesPerPage elements are leaf nodes. Unused nodes are zero.
 	 */
-	uint8		fp_nodes[1];
+	uint8		fp_nodes[FLEXIBLE_ARRAY_MEMBER];
 } FSMPageData;
 
 typedef FSMPageData *FSMPage;
diff --git a/src/include/storage/standby.h b/src/include/storage/standby.h
index 168c14c..f8f2e71 100644
--- a/src/include/storage/standby.h
+++ b/src/include/storage/standby.h
@@ -59,7 +59,7 @@ extern void StandbyReleaseOldLocks(int nxids, TransactionId *xids);
 typedef struct xl_standby_locks
 {
 	int			nlocks;			/* number of entries in locks array */
-	xl_standby_lock locks[1];	/* VARIABLE LENGTH ARRAY */
+	xl_standby_lock locks[FLEXIBLE_ARRAY_MEMBER];
 } xl_standby_locks;
 
 /*
@@ -74,7 +74,7 @@ typedef struct xl_running_xacts
 	TransactionId oldestRunningXid;		/* *not* oldestXmin */
 	TransactionId latestCompletedXid;	/* so we can set xmax */
 
-	TransactionId xids[1];		/* VARIABLE LENGTH ARRAY */
+	TransactionId xids[FLEXIBLE_ARRAY_MEMBER];
 } xl_running_xacts;
 
 #define MinSizeOfXactRunningXacts offsetof(xl_running_xacts, xids)
diff --git a/src/include/tsearch/dicts/regis.h b/src/include/tsearch/dicts/regis.h
index 0f3ef3f..89cc72f 100644
--- a/src/include/tsearch/dicts/regis.h
+++ b/src/include/tsearch/dicts/regis.h
@@ -21,7 +21,7 @@ typedef struct RegisNode
 				len:16,
 				unused:14;
 	struct RegisNode *next;
-	unsigned char data[1];
+	unsigned char data[FLEXIBLE_ARRAY_MEMBER];
 } RegisNode;
 
 #define  RNHDRSZ	(offsetof(RegisNode,data))
diff --git a/src/include/tsearch/dicts/spell.h b/src/include/tsearch/dicts/spell.h
index c8e70b2..9b65386 100644
--- a/src/include/tsearch/dicts/spell.h
+++ b/src/include/tsearch/dicts/spell.h
@@ -49,7 +49,7 @@ typedef struct
 typedef struct SPNode
 {
 	uint32		length;
-	SPNodeData	data[1];
+	SPNodeData	data[FLEXIBLE_ARRAY_MEMBER];
 } SPNode;
 
 #define SPNHDRSZ	(offsetof(SPNode,data))
@@ -70,7 +70,7 @@ typedef struct spell_struct
 			int			len;
 		}			d;
 	}			p;
-	char		word[1];		/* variable length, null-terminated */
+	char		word[FLEXIBLE_ARRAY_MEMBER];		/* variable length, null-terminated */
 } SPELL;
 
 #define SPELLHDRSZ	(offsetof(SPELL, word))
@@ -120,7 +120,7 @@ typedef struct AffixNode
 {
 	uint32		isvoid:1,
 				length:31;
-	AffixNodeData data[1];
+	AffixNodeData data[FLEXIBLE_ARRAY_MEMBER];
 } AffixNode;
 
 #define ANHRDSZ		   (offsetof(AffixNode, data))
diff --git a/src/include/tsearch/ts_type.h b/src/include/tsearch/ts_type.h
index 7e0737c..14cd8dd 100644
--- a/src/include/tsearch/ts_type.h
+++ b/src/include/tsearch/ts_type.h
@@ -63,7 +63,7 @@ typedef uint16 WordEntryPos;
 typedef struct
 {
 	uint16		npos;
-	WordEntryPos pos[1];		/* variable length */
+	WordEntryPos pos[FLEXIBLE_ARRAY_MEMBER];
 } WordEntryPosVector;
 
 
@@ -82,7 +82,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		size;
-	WordEntry	entries[1];		/* variable length */
+	WordEntry	entries[FLEXIBLE_ARRAY_MEMBER];
 	/* lexemes follow the entries[] array */
 } TSVectorData;
 
@@ -233,7 +233,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		size;			/* number of QueryItems */
-	char		data[1];		/* data starts here */
+	char		data[FLEXIBLE_ARRAY_MEMBER];		/* data starts here */
 } TSQueryData;
 
 typedef TSQueryData *TSQuery;
diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h
index b6e1c97..c992ed8 100644
--- a/src/include/utils/catcache.h
+++ b/src/include/utils/catcache.h
@@ -66,8 +66,8 @@ typedef struct catcache
 	long		cc_lsearches;	/* total # list-searches */
 	long		cc_lhits;		/* # of matches against existing lists */
 #endif
-	dlist_head	cc_bucket[1];	/* hash buckets --- VARIABLE LENGTH ARRAY */
-} CatCache;						/* VARIABLE LENGTH STRUCT */
+	dlist_head	cc_bucket[FLEXIBLE_ARRAY_MEMBER];	/* hash buckets */
+} CatCache;
 
 
 typedef struct catctup
@@ -147,8 +147,8 @@ typedef struct catclist
 	uint32		hash_value;		/* hash value for lookup keys */
 	HeapTupleData tuple;		/* header for tuple holding keys */
 	int			n_members;		/* number of member tuples */
-	CatCTup    *members[1];		/* members --- VARIABLE LENGTH ARRAY */
-} CatCList;						/* VARIABLE LENGTH STRUCT */
+	CatCTup    *members[FLEXIBLE_ARRAY_MEMBER];		/* members */
+} CatCList;
 
 
 typedef struct catcacheheader
diff --git a/src/include/utils/datetime.h b/src/include/utils/datetime.h
index 3cd921a..7bfb729 100644
--- a/src/include/utils/datetime.h
+++ b/src/include/utils/datetime.h
@@ -207,7 +207,7 @@ typedef struct
 typedef struct TimeZoneAbbrevTable
 {
 	int			numabbrevs;
-	datetkn		abbrevs[1];		/* VARIABLE LENGTH ARRAY */
+	datetkn		abbrevs[FLEXIBLE_ARRAY_MEMBER];
 } TimeZoneAbbrevTable;
 
 
diff --git a/src/include/utils/geo_decls.h b/src/include/utils/geo_decls.h
index 5c83a71..32f6a7b 100644
--- a/src/include/utils/geo_decls.h
+++ b/src/include/utils/geo_decls.h
@@ -82,7 +82,7 @@ typedef struct
 	int32		npts;
 	int32		closed;			/* is this a closed polygon? */
 	int32		dummy;			/* padding to make it double align */
-	Point		p[1];			/* variable length array of POINTs */
+	Point		p[FLEXIBLE_ARRAY_MEMBER];			/* variable length array of POINTs */
 } PATH;
 
 
@@ -124,7 +124,7 @@ typedef struct
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		npts;
 	BOX			boundbox;
-	Point		p[1];			/* variable length array of POINTs */
+	Point		p[FLEXIBLE_ARRAY_MEMBER];			/* variable length array of POINTs */
 } POLYGON;
 
 /*---------------------------------------------------------------------
diff --git a/src/include/utils/relmapper.h b/src/include/utils/relmapper.h
index 8f0b438..27edffa 100644
--- a/src/include/utils/relmapper.h
+++ b/src/include/utils/relmapper.h
@@ -28,7 +28,7 @@ typedef struct xl_relmap_update
 	Oid			dbid;			/* database ID, or 0 for shared map */
 	Oid			tsid;			/* database's tablespace, or pg_global */
 	int32		nbytes;			/* size of relmap data */
-	char		data[1];		/* VARIABLE LENGTH ARRAY */
+	char		data[FLEXIBLE_ARRAY_MEMBER];
 } xl_relmap_update;
 
 #define MinSizeOfRelmapUpdate offsetof(xl_relmap_update, data)
diff --git a/src/include/utils/varbit.h b/src/include/utils/varbit.h
index 4879a2e..ee1263d 100644
--- a/src/include/utils/varbit.h
+++ b/src/include/utils/varbit.h
@@ -24,7 +24,7 @@ typedef struct
 {
 	int32		vl_len_;		/* varlena header (do not touch directly!) */
 	int32		bit_len;		/* number of valid bits */
-	bits8		bit_dat[1];		/* bit string, most sig. byte first */
+	bits8		bit_dat[FLEXIBLE_ARRAY_MEMBER];		/* bit string, most sig. byte first */
 } VarBit;
 
 /*
diff --git a/src/interfaces/ecpg/ecpglib/extern.h b/src/interfaces/ecpg/ecpglib/extern.h
index 835e70c..a9f2de2 100644
--- a/src/interfaces/ecpg/ecpglib/extern.h
+++ b/src/interfaces/ecpg/ecpglib/extern.h
@@ -33,7 +33,7 @@ enum ARRAY_TYPE
 struct ECPGgeneric_varchar
 {
 	int			len;
-	char		arr[1];
+	char		arr[FLEXIBLE_ARRAY_MEMBER];
 };
 
 /*
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 9d561c2..f1cd30c 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -97,7 +97,7 @@
 	/* first item added must be a label */
 	Assert(ns_top != NULL || itemtype == PLPGSQL_NSTYPE_LABEL);
 
-	nse = palloc(sizeof(PLpgSQL_nsitem) + strlen(name));
+	nse = palloc(offsetof(PLpgSQL_nsitem, name) + strlen(name) + 1);
 	nse->itemtype = itemtype;
 	nse->itemno = itemno;
 	nse->prev = ns_top;
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 8996501..346953b 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -318,7 +318,7 @@ typedef struct PLpgSQL_nsitem
 	int			itemtype;
 	int			itemno;
 	struct PLpgSQL_nsitem *prev;
-	char		name[1];		/* actually, as long as needed */
+	char		name[FLEXIBLE_ARRAY_MEMBER]; // FIXME
 } PLpgSQL_nsitem;