Make xlog_internal.h includable in frontend context.

This makes unnecessary the ugly hack used to #include postgres.h in
pg_basebackup.

Based on Alvaro Herrera's patch

src/backend/access/rmgrdesc/xlogdesc.c

@@ -14,6 +14,7 @@
  */
 #include "postgres.h"
 
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "catalog/pg_control.h"
 #include "utils/guc.h"

src/backend/access/transam/xlogarchive.c

@@ -20,6 +20,7 @@
 #include <signal.h>
 #include <unistd.h>
 
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "miscadmin.h"
 #include "postmaster/startup.h"

src/backend/access/transam/xlogfuncs.c

@@ -18,6 +18,7 @@
 
 #include "access/htup_details.h"
 #include "access/xlog.h"
+#include "access/xlog_fn.h"
 #include "access/xlog_internal.h"
 #include "access/xlogutils.h"
 #include "catalog/catalog.h"

src/backend/postmaster/bgwriter.c

@@ -39,6 +39,7 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "libpq/pqsignal.h"
 #include "miscadmin.h"

src/backend/postmaster/checkpointer.c

@@ -41,6 +41,7 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "libpq/pqsignal.h"
 #include "miscadmin.h"

src/backend/postmaster/pgarch.c

@@ -32,6 +32,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "libpq/pqsignal.h"
 #include "miscadmin.h"

src/bin/pg_basebackup/pg_basebackup.c

@@ -11,13 +11,7 @@
  *-------------------------------------------------------------------------
  */
 
-/*
- * We have to use postgres.h not postgres_fe.h here, because there's so much
- * backend-only stuff in the XLOG include files we need.  But we need a
- * frontend-ish environment otherwise.	Hence this ugly hack.
- */
-#define FRONTEND 1
-#include "postgres.h"
+#include "postgres_fe.h"
 #include "libpq-fe.h"
 
 #include <unistd.h>

src/bin/pg_basebackup/pg_receivexlog.c

@@ -12,13 +12,7 @@
  *-------------------------------------------------------------------------
  */
 
-/*
- * We have to use postgres.h not postgres_fe.h here, because there's so much
- * backend-only stuff in the XLOG include files we need.  But we need a
- * frontend-ish environment otherwise.	Hence this ugly hack.
- */
-#define FRONTEND 1
-#include "postgres.h"
+#include "postgres_fe.h"
 #include "libpq-fe.h"
 #include "libpq/pqsignal.h"
 #include "access/xlog_internal.h"

src/bin/pg_basebackup/receivelog.c

@@ -11,14 +11,7 @@
  *		  src/bin/pg_basebackup/receivelog.c
  *-------------------------------------------------------------------------
  */
-
-/*
- * We have to use postgres.h not postgres_fe.h here, because there's so much
- * backend-only stuff in the XLOG include files we need.  But we need a
- * frontend-ish environment otherwise.	Hence this ugly hack.
- */
-#define FRONTEND 1
-#include "postgres.h"
+#include "postgres_fe.h"
 
 #include <sys/stat.h>
 #include <sys/time.h>
@@ -30,8 +23,6 @@
 
 #include "libpq-fe.h"
 #include "access/xlog_internal.h"
-#include "utils/datetime.h"
-#include "utils/timestamp.h"
 
 #include "receivelog.h"
 #include "streamutil.h"

src/bin/pg_basebackup/streamutil.c

@@ -11,13 +11,7 @@
  *-------------------------------------------------------------------------
  */
 
-/*
- * We have to use postgres.h not postgres_fe.h here, because there's so much
- * backend-only stuff in the XLOG include files we need.  But we need a
- * frontend-ish environment otherwise.	Hence this ugly hack.
- */
-#define FRONTEND 1
-#include "postgres.h"
+#include "postgres_fe.h"
 #include "streamutil.h"
 
 #include <stdio.h>

src/include/access/xlog_fn.h

+/*
+ * xlog_fn.h
+ *
+ * PostgreSQL transaction log SQL-callable function declarations
+ *
+ * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/xlog_fn.h
+ */
+#ifndef XLOG_FN_H
+#define XLOG_FN_H
+
+#include "fmgr.h"
+
+extern Datum pg_start_backup(PG_FUNCTION_ARGS);
+extern Datum pg_stop_backup(PG_FUNCTION_ARGS);
+extern Datum pg_switch_xlog(PG_FUNCTION_ARGS);
+extern Datum pg_create_restore_point(PG_FUNCTION_ARGS);
+extern Datum pg_current_xlog_location(PG_FUNCTION_ARGS);
+extern Datum pg_current_xlog_insert_location(PG_FUNCTION_ARGS);
+extern Datum pg_last_xlog_receive_location(PG_FUNCTION_ARGS);
+extern Datum pg_last_xlog_replay_location(PG_FUNCTION_ARGS);
+extern Datum pg_last_xact_replay_timestamp(PG_FUNCTION_ARGS);
+extern Datum pg_xlogfile_name_offset(PG_FUNCTION_ARGS);
+extern Datum pg_xlogfile_name(PG_FUNCTION_ARGS);
+extern Datum pg_is_in_recovery(PG_FUNCTION_ARGS);
+extern Datum pg_xlog_replay_pause(PG_FUNCTION_ARGS);
+extern Datum pg_xlog_replay_resume(PG_FUNCTION_ARGS);
+extern Datum pg_is_xlog_replay_paused(PG_FUNCTION_ARGS);
+extern Datum pg_xlog_location_diff(PG_FUNCTION_ARGS);
+extern Datum pg_is_in_backup(PG_FUNCTION_ARGS);
+extern Datum pg_backup_start_time(PG_FUNCTION_ARGS);
+
+#endif   /* XLOG_FN_H */

src/include/access/xlog_internal.h

@@ -8,6 +8,9 @@
  * needed by rmgr routines (redo support for individual record types).
  * So the XLogRecord typedef and associated stuff appear in xlog.h.
  *
+ * Note: This file must be includable in both frontend and backend contexts,
+ * to allow stand-alone tools like pg_receivexlog to deal with WAL files.
+ *
  * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
@@ -16,8 +19,9 @@
 #ifndef XLOG_INTERNAL_H
 #define XLOG_INTERNAL_H
 
-#include "access/xlog.h"
-#include "fmgr.h"
+#include "access/xlogdefs.h"
+#include "datatype/timestamp.h"
+#include "lib/stringinfo.h"
 #include "pgtime.h"
 #include "storage/block.h"
 #include "storage/relfilenode.h"
@@ -225,6 +229,12 @@ typedef struct xl_restore_point
 } xl_restore_point;
 
 
+/*
+ * XLogRecord is defined in xlog.h, but we avoid #including that to keep
+ * this file includable in stand-alone programs.
+ */
+struct XLogRecord;
+
 /*
  * Method table for resource managers.
  *
@@ -233,7 +243,7 @@ typedef struct xl_restore_point
 typedef struct RmgrData
 {
 	const char *rm_name;
-	void		(*rm_redo) (XLogRecPtr lsn, XLogRecord *rptr);
+	void		(*rm_redo) (XLogRecPtr lsn, struct XLogRecord *rptr);
 	void		(*rm_desc) (StringInfo buf, uint8 xl_info, char *rec);
 	void		(*rm_startup) (void);
 	void		(*rm_cleanup) (void);
@@ -272,26 +282,4 @@ extern bool XLogArchiveCheckDone(const char *xlog);
 extern bool XLogArchiveIsBusy(const char *xlog);
 extern void XLogArchiveCleanup(const char *xlog);
 
-/*
- * These aren't in xlog.h because I'd rather not include fmgr.h there.
- */
-extern Datum pg_start_backup(PG_FUNCTION_ARGS);
-extern Datum pg_stop_backup(PG_FUNCTION_ARGS);
-extern Datum pg_switch_xlog(PG_FUNCTION_ARGS);
-extern Datum pg_create_restore_point(PG_FUNCTION_ARGS);
-extern Datum pg_current_xlog_location(PG_FUNCTION_ARGS);
-extern Datum pg_current_xlog_insert_location(PG_FUNCTION_ARGS);
-extern Datum pg_last_xlog_receive_location(PG_FUNCTION_ARGS);
-extern Datum pg_last_xlog_replay_location(PG_FUNCTION_ARGS);
-extern Datum pg_last_xact_replay_timestamp(PG_FUNCTION_ARGS);
-extern Datum pg_xlogfile_name_offset(PG_FUNCTION_ARGS);
-extern Datum pg_xlogfile_name(PG_FUNCTION_ARGS);
-extern Datum pg_is_in_recovery(PG_FUNCTION_ARGS);
-extern Datum pg_xlog_replay_pause(PG_FUNCTION_ARGS);
-extern Datum pg_xlog_replay_resume(PG_FUNCTION_ARGS);
-extern Datum pg_is_xlog_replay_paused(PG_FUNCTION_ARGS);
-extern Datum pg_xlog_location_diff(PG_FUNCTION_ARGS);
-extern Datum pg_is_in_backup(PG_FUNCTION_ARGS);
-extern Datum pg_backup_start_time(PG_FUNCTION_ARGS);
-
 #endif   /* XLOG_INTERNAL_H */