Fix new warnings from GCC 7

This addresses the new warning types -Wformat-truncation
-Wformat-overflow that are part of -Wall, via -Wformat, in GCC 7.

contrib/pg_archivecleanup/pg_archivecleanup.c

@@ -41,7 +41,7 @@ char	   *additional_ext = NULL;		/* Extension to remove from filenames */
 
 char	   *archiveLocation;	/* where to find the archive? */
 char	   *restartWALFileName; /* the file from which we can restart restore */
-char		WALFilePath[MAXPGPATH];		/* the file path including archive */
+char		WALFilePath[MAXPGPATH * 2];		/* the file path including archive */
 char		exclusiveCleanupFileName[MAXPGPATH];		/* the oldest file we
 														 * want to remain in
 														 * archive */
@@ -144,7 +144,7 @@ CleanupPriorWALFiles(void)
 				 * extension that might have been chopped off before testing
 				 * the sequence.
 				 */
-				snprintf(WALFilePath, MAXPGPATH, "%s/%s",
+				snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
 						 archiveLocation, xlde->d_name);
 
 				if (dryrun)

contrib/pg_standby/pg_standby.c

@@ -66,7 +66,7 @@ char	   *xlogFilePath;		/* where we are going to restore to */
 char	   *nextWALFileName;	/* the file we need to get from archive */
 char	   *restartWALFileName; /* the file from which we can restart restore */
 char	   *priorWALFileName;	/* the file we need to get from archive */
-char		WALFilePath[MAXPGPATH];		/* the file path including archive */
+char		WALFilePath[MAXPGPATH * 2];		/* the file path including archive */
 char		restoreCommand[MAXPGPATH];	/* run this to restore */
 char		exclusiveCleanupFileName[MAXPGPATH];		/* the file we need to
 														 * get from archive */
@@ -277,9 +277,9 @@ CustomizableCleanupPriorWALFiles(void)
 				  strcmp(xlde->d_name + 8, exclusiveCleanupFileName + 8) < 0)
 				{
 #ifdef WIN32
-					snprintf(WALFilePath, MAXPGPATH, "%s\\%s", archiveLocation, xlde->d_name);
+					snprintf(WALFilePath, sizeof(WALFilePath), "%s\\%s", archiveLocation, xlde->d_name);
 #else
-					snprintf(WALFilePath, MAXPGPATH, "%s/%s", archiveLocation, xlde->d_name);
+					snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s", archiveLocation, xlde->d_name);
 #endif
 
 					if (debug)

contrib/pg_upgrade/pg_upgrade.h

@@ -135,8 +135,8 @@ typedef struct
  */
 typedef struct
 {
-	char		old_dir[MAXPGPATH];
+	char		old_dir[MAXPGPATH * 2];
-	char		new_dir[MAXPGPATH];
+	char		new_dir[MAXPGPATH * 2];
 
 	/*
 	 * old/new relfilenodes might differ for pg_largeobject(_metadata) indexes

src/backend/access/transam/xlog.c

@@ -3757,7 +3757,7 @@ CleanupBackupHistory(void)
 {
 	DIR		   *xldir;
 	struct dirent *xlde;
-	char		path[MAXPGPATH];
+	char		path[MAXPGPATH + sizeof(XLOGDIR)];
 
 	xldir = AllocateDir(XLOGDIR);
 	if (xldir == NULL)
@@ -3778,7 +3778,7 @@ CleanupBackupHistory(void)
 				ereport(DEBUG2,
 				(errmsg("removing transaction log backup history file \"%s\"",
 						xlde->d_name)));
-				snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
+				snprintf(path, sizeof(path), XLOGDIR "/%s", xlde->d_name);
 				unlink(path);
 				XLogArchiveCleanup(xlde->d_name);
 			}

src/backend/replication/basebackup.c

@@ -115,7 +115,7 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
 		/* Collect information about all tablespaces */
 		while ((de = ReadDir(tblspcdir, "pg_tblspc")) != NULL)
 		{
-			char		fullpath[MAXPGPATH];
+			char		fullpath[MAXPGPATH + 10];
 			char		linkpath[MAXPGPATH];
 			char	   *relpath = NULL;
 			int			rllen;
@@ -821,7 +821,7 @@ sendDir(char *path, int basepathlen, bool sizeonly, List *tablespaces)
 {
 	DIR		   *dir;
 	struct dirent *de;
-	char		pathbuf[MAXPGPATH];
+	char		pathbuf[MAXPGPATH * 2];
 	struct stat statbuf;
 	int64		size = 0;
 
@@ -855,7 +855,7 @@ sendDir(char *path, int basepathlen, bool sizeonly, List *tablespaces)
 			ereport(ERROR,
 				(errmsg("shutdown requested, aborting active base backup")));
 
-		snprintf(pathbuf, MAXPGPATH, "%s/%s", path, de->d_name);
+		snprintf(pathbuf, sizeof(pathbuf), "%s/%s", path, de->d_name);
 
 		/* Skip postmaster.pid and postmaster.opts in the data directory */
 		if (strcmp(pathbuf, "./postmaster.pid") == 0 ||

src/backend/storage/file/copydir.c

@@ -49,8 +49,8 @@ copydir(char *fromdir, char *todir, bool recurse)
 {
 	DIR		   *xldir;
 	struct dirent *xlde;
-	char		fromfile[MAXPGPATH];
+	char		fromfile[MAXPGPATH * 2];
-	char		tofile[MAXPGPATH];
+	char		tofile[MAXPGPATH * 2];
 
 	if (mkdir(todir, S_IRWXU) != 0)
 		ereport(ERROR,
@@ -74,8 +74,8 @@ copydir(char *fromdir, char *todir, bool recurse)
 			strcmp(xlde->d_name, "..") == 0)
 			continue;
 
-		snprintf(fromfile, MAXPGPATH, "%s/%s", fromdir, xlde->d_name);
+		snprintf(fromfile, sizeof(fromfile), "%s/%s", fromdir, xlde->d_name);
-		snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
+		snprintf(tofile, sizeof(tofile), "%s/%s", todir, xlde->d_name);
 
 		if (lstat(fromfile, &fst) < 0)
 			ereport(ERROR,
@@ -110,7 +110,7 @@ copydir(char *fromdir, char *todir, bool recurse)
 			strcmp(xlde->d_name, "..") == 0)
 			continue;
 
-		snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
+		snprintf(tofile, sizeof(tofile), "%s/%s", todir, xlde->d_name);
 
 		/*
 		 * We don't need to sync subdirectories here since the recursive

src/backend/storage/file/fd.c

@@ -2282,7 +2282,7 @@ CleanupTempFiles(bool isProcExit)
 void
 RemovePgTempFiles(void)
 {
-	char		temp_path[MAXPGPATH];
+	char		temp_path[MAXPGPATH + 10 + sizeof(TABLESPACE_VERSION_DIRECTORY) + sizeof(PG_TEMP_FILES_DIR)];
 	DIR		   *spc_dir;
 	struct dirent *spc_de;
 
@@ -2330,7 +2330,7 @@ RemovePgTempFilesInDir(const char *tmpdirname)
 {
 	DIR		   *temp_dir;
 	struct dirent *temp_de;
-	char		rm_path[MAXPGPATH];
+	char		rm_path[MAXPGPATH * 2];
 
 	temp_dir = AllocateDir(tmpdirname);
 	if (temp_dir == NULL)
@@ -2371,7 +2371,7 @@ RemovePgTempRelationFiles(const char *tsdirname)
 {
 	DIR		   *ts_dir;
 	struct dirent *de;
-	char		dbspace_path[MAXPGPATH];
+	char		dbspace_path[MAXPGPATH * 2];
 
 	ts_dir = AllocateDir(tsdirname);
 	if (ts_dir == NULL)
@@ -2412,7 +2412,7 @@ RemovePgTempRelationFilesInDbspace(const char *dbspacedirname)
 {
 	DIR		   *dbspace_dir;
 	struct dirent *de;
-	char		rm_path[MAXPGPATH];
+	char		rm_path[MAXPGPATH * 2];
 
 	dbspace_dir = AllocateDir(dbspacedirname);
 	if (dbspace_dir == NULL)
@@ -2599,7 +2599,7 @@ walkdir(const char *path,
 
 	while ((de = ReadDirExtended(dir, path, elevel)) != NULL)
 	{
-		char		subpath[MAXPGPATH];
+		char		subpath[MAXPGPATH * 2];
 		struct stat fst;
 		int			sret;
 
@@ -2609,7 +2609,7 @@ walkdir(const char *path,
 			strcmp(de->d_name, "..") == 0)
 			continue;
 
-		snprintf(subpath, MAXPGPATH, "%s/%s", path, de->d_name);
+		snprintf(subpath, sizeof(subpath), "%s/%s", path, de->d_name);
 
 		if (process_symlinks)
 			sret = stat(subpath, &fst);

src/backend/storage/file/reinit.c

@@ -47,7 +47,7 @@ typedef struct
 void
 ResetUnloggedRelations(int op)
 {
-	char		temp_path[MAXPGPATH];
+	char		temp_path[MAXPGPATH + 10 + sizeof(TABLESPACE_VERSION_DIRECTORY)];
 	DIR		   *spc_dir;
 	struct dirent *spc_de;
 	MemoryContext tmpctx,
@@ -105,7 +105,7 @@ ResetUnloggedRelationsInTablespaceDir(const char *tsdirname, int op)
 {
 	DIR		   *ts_dir;
 	struct dirent *de;
-	char		dbspace_path[MAXPGPATH];
+	char		dbspace_path[MAXPGPATH * 2];
 
 	ts_dir = AllocateDir(tsdirname);
 	if (ts_dir == NULL)
@@ -146,7 +146,7 @@ ResetUnloggedRelationsInDbspaceDir(const char *dbspacedirname, int op)
 {
 	DIR		   *dbspace_dir;
 	struct dirent *de;
-	char		rm_path[MAXPGPATH];
+	char		rm_path[MAXPGPATH * 2];
 
 	/* Caller must specify at least one operation. */
 	Assert((op & (UNLOGGED_RELATION_CLEANUP | UNLOGGED_RELATION_INIT)) != 0);
@@ -309,7 +309,7 @@ ResetUnloggedRelationsInDbspaceDir(const char *dbspacedirname, int op)
 			ForkNumber	forkNum;
 			int			oidchars;
 			char		oidbuf[OIDCHARS + 1];
-			char		srcpath[MAXPGPATH];
+			char		srcpath[MAXPGPATH * 2];
 			char		dstpath[MAXPGPATH];
 
 			/* Skip anything that doesn't look like a relation data file. */

src/backend/utils/adt/dbsize.c

@@ -37,7 +37,7 @@ db_dir_size(const char *path)
 	int64		dirsize = 0;
 	struct dirent *direntry;
 	DIR		   *dirdesc;
-	char		filename[MAXPGPATH];
+	char		filename[MAXPGPATH * 2];
 
 	dirdesc = AllocateDir(path);
 
@@ -54,7 +54,7 @@ db_dir_size(const char *path)
 			strcmp(direntry->d_name, "..") == 0)
 			continue;
 
-		snprintf(filename, MAXPGPATH, "%s/%s", path, direntry->d_name);
+		snprintf(filename, sizeof(filename), "%s/%s", path, direntry->d_name);
 
 		if (stat(filename, &fst) < 0)
 		{
@@ -82,7 +82,7 @@ calculate_database_size(Oid dbOid)
 	DIR		   *dirdesc;
 	struct dirent *direntry;
 	char		dirpath[MAXPGPATH];
-	char		pathname[MAXPGPATH];
+	char		pathname[MAXPGPATH + 12 + sizeof(TABLESPACE_VERSION_DIRECTORY)];
 	AclResult	aclresult;
 
 	/* User must have connect privilege for target database */
@@ -94,7 +94,7 @@ calculate_database_size(Oid dbOid)
 	/* Shared storage in pg_global is not counted */
 
 	/* Include pg_default storage */
-	snprintf(pathname, MAXPGPATH, "base/%u", dbOid);
+	snprintf(pathname, sizeof(pathname), "base/%u", dbOid);
 	totalsize = db_dir_size(pathname);
 
 	/* Scan the non-default tablespaces */
@@ -114,7 +114,7 @@ calculate_database_size(Oid dbOid)
 			strcmp(direntry->d_name, "..") == 0)
 			continue;
 
-		snprintf(pathname, MAXPGPATH, "pg_tblspc/%s/%s/%u",
+		snprintf(pathname, sizeof(pathname), "pg_tblspc/%s/%s/%u",
 				 direntry->d_name, TABLESPACE_VERSION_DIRECTORY, dbOid);
 		totalsize += db_dir_size(pathname);
 	}
@@ -162,7 +162,7 @@ static int64
 calculate_tablespace_size(Oid tblspcOid)
 {
 	char		tblspcPath[MAXPGPATH];
-	char		pathname[MAXPGPATH];
+	char		pathname[MAXPGPATH * 2];
 	int64		totalsize = 0;
 	DIR		   *dirdesc;
 	struct dirent *direntry;
@@ -204,7 +204,7 @@ calculate_tablespace_size(Oid tblspcOid)
 			strcmp(direntry->d_name, "..") == 0)
 			continue;
 
-		snprintf(pathname, MAXPGPATH, "%s/%s", tblspcPath, direntry->d_name);
+		snprintf(pathname, sizeof(pathname), "%s/%s", tblspcPath, direntry->d_name);
 
 		if (stat(pathname, &fst) < 0)
 		{

src/backend/utils/cache/relcache.c

@@ -4659,7 +4659,7 @@ RelationCacheInitFileRemove(void)
 	const char *tblspcdir = "pg_tblspc";
 	DIR		   *dir;
 	struct dirent *de;
-	char		path[MAXPGPATH];
+	char		path[MAXPGPATH + 10 + sizeof(TABLESPACE_VERSION_DIRECTORY)];
 
 	/*
 	 * We zap the shared cache file too.  In theory it can't get out of sync
@@ -4701,7 +4701,7 @@ RelationCacheInitFileRemoveInDir(const char *tblspcpath)
 {
 	DIR		   *dir;
 	struct dirent *de;
-	char		initfilename[MAXPGPATH];
+	char		initfilename[MAXPGPATH * 2];
 
 	/* Scan the tablespace directory to find per-database directories */
 	dir = AllocateDir(tblspcpath);

src/backend/utils/error/elog.c

@@ -1886,7 +1886,7 @@ setup_formatted_log_time(void)
 {
 	struct timeval tv;
 	pg_time_t	stamp_time;
-	char		msbuf[8];
+	char		msbuf[13];
 
 	gettimeofday(&tv, NULL);
 	stamp_time = (pg_time_t) tv.tv_sec;

src/backend/utils/time/snapmgr.c

@@ -1154,7 +1154,7 @@ XactHasExportedSnapshots(void)
 void
 DeleteAllExportedSnapshotFiles(void)
 {
-	char		buf[MAXPGPATH];
+	char		buf[MAXPGPATH + sizeof(SNAPSHOT_EXPORT_DIR)];
 	DIR		   *s_dir;
 	struct dirent *s_de;
 
@@ -1175,7 +1175,7 @@ DeleteAllExportedSnapshotFiles(void)
 			strcmp(s_de->d_name, "..") == 0)
 			continue;
 
-		snprintf(buf, MAXPGPATH, SNAPSHOT_EXPORT_DIR "/%s", s_de->d_name);
+		snprintf(buf, sizeof(buf), SNAPSHOT_EXPORT_DIR "/%s", s_de->d_name);
 		/* Again, unlink failure is not worthy of FATAL */
 		if (unlink(buf))
 			elog(LOG, "could not unlink file \"%s\": %m", buf);

src/bin/pg_basebackup/pg_receivexlog.c

@@ -125,7 +125,7 @@ FindStreamingStart(XLogRecPtr currentpos, uint32 currenttimeline)
 
 	while (errno = 0, (dirent = readdir(dir)) != NULL)
 	{
-		char		fullpath[MAXPGPATH];
+		char		fullpath[MAXPGPATH * 2];
 		struct stat statbuf;
 		uint32		tli,
 					log,

src/bin/pg_resetxlog/pg_resetxlog.c

@@ -838,7 +838,7 @@ KillExistingXLOG(void)
 {
 	DIR		   *xldir;
 	struct dirent *xlde;
-	char		path[MAXPGPATH];
+	char		path[MAXPGPATH + sizeof(XLOGDIR)];
 
 	xldir = opendir(XLOGDIR);
 	if (xldir == NULL)
@@ -853,7 +853,7 @@ KillExistingXLOG(void)
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 		{
-			snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
+			snprintf(path, sizeof(path), "%s/%s", XLOGDIR, xlde->d_name);
 			if (unlink(path) < 0)
 			{
 				fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
@@ -891,11 +891,11 @@ KillExistingXLOG(void)
 static void
 KillExistingArchiveStatus(void)
 {
+#define ARCHSTATDIR XLOGDIR "/archive_status"
+
 	DIR		   *xldir;
 	struct dirent *xlde;
-	char		path[MAXPGPATH];
+	char		path[MAXPGPATH + sizeof(ARCHSTATDIR)];
-
-#define ARCHSTATDIR XLOGDIR "/archive_status"
 
 	xldir = opendir(ARCHSTATDIR);
 	if (xldir == NULL)
@@ -911,7 +911,7 @@ KillExistingArchiveStatus(void)
 			(strcmp(xlde->d_name + 24, ".ready") == 0 ||
 			 strcmp(xlde->d_name + 24, ".done") == 0))
 		{
-			snprintf(path, MAXPGPATH, "%s/%s", ARCHSTATDIR, xlde->d_name);
+			snprintf(path, sizeof(path), "%s/%s", ARCHSTATDIR, xlde->d_name);
 			if (unlink(path) < 0)
 			{
 				fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),

src/timezone/pgtz.c

@@ -437,7 +437,7 @@ pg_tzenumerate_next(pg_tzenum *dir)
 	while (dir->depth >= 0)
 	{
 		struct dirent *direntry;
-		char		fullname[MAXPGPATH];
+		char		fullname[MAXPGPATH * 2];
 		struct stat statbuf;
 
 		direntry = ReadDir(dir->dirdesc[dir->depth], dir->dirname[dir->depth]);
@@ -454,7 +454,7 @@ pg_tzenumerate_next(pg_tzenum *dir)
 		if (direntry->d_name[0] == '.')
 			continue;
 
-		snprintf(fullname, MAXPGPATH, "%s/%s",
+		snprintf(fullname, sizeof(fullname), "%s/%s",
 				 dir->dirname[dir->depth], direntry->d_name);
 		if (stat(fullname, &statbuf) != 0)
 			ereport(ERROR,