Tweak __attribute__-wrapping macros for better pgindent results.

This improves on commit bbfd7edae5 by
making two simple changes:

* pg_attribute_noreturn now takes parentheses, ie pg_attribute_noreturn().
Likewise pg_attribute_unused(), pg_attribute_packed().  This reduces
pgindent's tendency to misformat declarations involving them.

* attributes are now always attached to function declarations, not
definitions.  Previously some places were taking creative shortcuts,
which were not merely candidates for bad misformatting by pgindent
but often were outright wrong anyway.  (It does little good to put a
noreturn annotation where callers can't see it.)  In any case, if
we would like to believe that these macros can be used with non-gcc
compilers, we should avoid gratuitous variance in usage patterns.

I also went through and manually improved the formatting of a lot of
declarations, and got rid of excessively repetitive (and now obsolete
anyway) comments informing the reader what pg_attribute_printf is for.

src/backend/access/transam/xlogreader.c

@@ -32,11 +32,7 @@ static bool ValidXLogRecord(XLogReaderState *state, XLogRecord *record,
 				XLogRecPtr recptr);
 static int ReadPageInternal(XLogReaderState *state, XLogRecPtr pageptr,
 				 int reqLen);
-static void
-report_invalid_record(XLogReaderState *state, const char *fmt,...)
-/* This extension allows gcc to check the format string for consistency with
-   the supplied arguments. */
-pg_attribute_printf(2, 3);
+static void report_invalid_record(XLogReaderState *state, const char *fmt,...) pg_attribute_printf(2, 3);
 
 static void ResetDecoder(XLogReaderState *state);
 

src/backend/postmaster/autovacuum.c

@@ -281,8 +281,8 @@ int			AutovacuumLauncherPid = 0;
 static pid_t avlauncher_forkexec(void);
 static pid_t avworker_forkexec(void);
 #endif
-NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn;
-NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]) pg_attribute_noreturn;
+NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
+NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]) pg_attribute_noreturn();
 
 static Oid	do_start_worker(void);
 static void launcher_determine_sleep(bool canlaunch, bool recursing,

src/backend/postmaster/pgarch.c

@@ -86,7 +86,7 @@ static volatile sig_atomic_t ready_to_stop = false;
 static pid_t pgarch_forkexec(void);
 #endif
 
-NON_EXEC_STATIC void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn;
+NON_EXEC_STATIC void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn();
 static void pgarch_exit(SIGNAL_ARGS);
 static void ArchSigHupHandler(SIGNAL_ARGS);
 static void ArchSigTermHandler(SIGNAL_ARGS);

src/backend/postmaster/pgstat.c

@@ -251,7 +251,7 @@ static instr_time total_func_time;
 static pid_t pgstat_forkexec(void);
 #endif
 
-NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) pg_attribute_noreturn;
+NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) pg_attribute_noreturn();
 static void pgstat_exit(SIGNAL_ARGS);
 static void pgstat_beshutdown_hook(int code, Datum arg);
 static void pgstat_sighup_handler(SIGNAL_ARGS);

src/backend/postmaster/postmaster.c

@@ -380,8 +380,8 @@ static void LogChildExit(int lev, const char *procname,
 			 int pid, int exitstatus);
 static void PostmasterStateMachine(void);
 static void BackendInitialize(Port *port);
-static void BackendRun(Port *port) pg_attribute_noreturn;
-static void ExitPostmaster(int status) pg_attribute_noreturn;
+static void BackendRun(Port *port) pg_attribute_noreturn();
+static void ExitPostmaster(int status) pg_attribute_noreturn();
 static int	ServerLoop(void);
 static int	BackendStartup(Port *port);
 static int	ProcessStartupPacket(Port *port, bool SSLdone);

src/backend/postmaster/syslogger.c

@@ -130,7 +130,7 @@ static volatile sig_atomic_t rotation_requested = false;
 static pid_t syslogger_forkexec(void);
 static void syslogger_parseArgs(int argc, char *argv[]);
 #endif
-NON_EXEC_STATIC void SysLoggerMain(int argc, char *argv[]) pg_attribute_noreturn;
+NON_EXEC_STATIC void SysLoggerMain(int argc, char *argv[]) pg_attribute_noreturn();
 static void process_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
 static void flush_pipe_input(char *logbuffer, int *bytes_in_logbuffer);
 static void open_csvlogfile(void);

src/backend/replication/repl_scanner.l

@@ -205,7 +205,7 @@ addlitchar(unsigned char ychar)
 	appendStringInfoChar(&litbuf, ychar);
 }
 
-void pg_attribute_noreturn
+void
 yyerror(const char *message)
 {
 	ereport(ERROR,

src/backend/replication/walsender.c

@@ -193,7 +193,7 @@ typedef void (*WalSndSendDataCallback) (void);
 static void WalSndLoop(WalSndSendDataCallback send_data);
 static void InitWalSenderSlot(void);
 static void WalSndKill(int code, Datum arg);
-static void WalSndShutdown(void) pg_attribute_noreturn;
+static void WalSndShutdown(void) pg_attribute_noreturn();
 static void XLogSendPhysical(void);
 static void XLogSendLogical(void);
 static void WalSndDone(WalSndSendDataCallback send_data);

src/backend/utils/error/elog.c

@@ -82,11 +82,7 @@
 #undef _
 #define _(x) err_gettext(x)
 
-static const char *
-err_gettext(const char *str)
-/* This extension allows gcc to check the format string for consistency with
-   the supplied arguments. */
-pg_attribute_format_arg(1);
+static const char *err_gettext(const char *str) pg_attribute_format_arg(1);
 static void set_errdata_field(MemoryContextData *cxt, char **ptr, const char *str);
 
 /* Global variables */

src/backend/utils/misc/guc.c

@@ -129,10 +129,7 @@ char	   *GUC_check_errmsg_string;
 char	   *GUC_check_errdetail_string;
 char	   *GUC_check_errhint_string;
 
-static void
-do_serialize(char **destptr, Size *maxbytes, const char *fmt,...)
-/* This lets gcc check the format string for consistency. */
-pg_attribute_printf(3, 4);
+static void do_serialize(char **destptr, Size *maxbytes, const char *fmt,...) pg_attribute_printf(3, 4);
 
 static void set_config_sourcefile(const char *name, char *sourcefile,
 					  int sourceline);