[e2fsprogs PATCH] libext2fs: consistently use #ifdefs in ext2fs_print_bmap_statistics()

[e2fsprogs PATCH] libext2fs: consistently use #ifdefs in ext2fs_print_bmap_statistics()

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Since the 'now' variable is only used to calculate 'inuse', and 'inuse'
is only used when defined(ENABLE_BMAP_STATS_OPS), it makes sense to
guard the declaration and initialization of 'now' and 'inuse' by the
same condition, just like the '*_perc' variables in the same function.

This addresses the following compiler warning with clang -Wall:

gen_bitmap64.c:187:9: warning: variable 'inuse' set but not used [-Wunused-but-set-variable]
        double inuse;
               ^

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 lib/ext2fs/gen_bitmap64.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
index c860c10e..1a1eeefe 100644
--- a/lib/ext2fs/gen_bitmap64.c
+++ b/lib/ext2fs/gen_bitmap64.c
@@ -183,11 +183,9 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
 #ifdef ENABLE_BMAP_STATS_OPS
 	float mark_seq_perc = 0.0, test_seq_perc = 0.0;
 	float mark_back_perc = 0.0, test_back_perc = 0.0;
-#endif
-	double inuse;
 	struct timeval now;
+	double inuse;
 
-#ifdef ENABLE_BMAP_STATS_OPS
 	if (stats->test_count) {
 		test_seq_perc = ((float)stats->test_seq /
 				 stats->test_count) * 100;
@@ -201,7 +199,6 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
 		mark_back_perc = ((float)stats->mark_back /
 				  stats->mark_count) * 100;
 	}
-#endif
 
 	if (gettimeofday(&now, (struct timezone *) NULL) == -1) {
 		perror("gettimeofday");
@@ -212,6 +209,7 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
 		(((double) now.tv_usec) * 0.000001);
 	inuse -= (double) stats->created.tv_sec + \
 		(((double) stats->created.tv_usec) * 0.000001);
+#endif /* ENABLE_BMAP_STATS_OPS */
 
 	fprintf(stderr, "\n[+] %s bitmap (type %d)\n", bitmap->description,
 		stats->type);
-- 
2.39.0

Re: [e2fsprogs PATCH] libext2fs: consistently use #ifdefs in ext2fs_print_bmap_statistics()

[Lukas Czerner]

On Wed, Jan 04, 2023 at 01:01:16AM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Since the 'now' variable is only used to calculate 'inuse', and 'inuse'
> is only used when defined(ENABLE_BMAP_STATS_OPS), it makes sense to
> guard the declaration and initialization of 'now' and 'inuse' by the
> same condition, just like the '*_perc' variables in the same function.
> 
> This addresses the following compiler warning with clang -Wall:
> 
> gen_bitmap64.c:187:9: warning: variable 'inuse' set but not used [-Wunused-but-set-variable]
>         double inuse;
>                ^

Looks good, thanks!

Reviewed-by: Lukas Czerner <lczerner@redhat.com>

> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  lib/ext2fs/gen_bitmap64.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
> index c860c10e..1a1eeefe 100644
> --- a/lib/ext2fs/gen_bitmap64.c
> +++ b/lib/ext2fs/gen_bitmap64.c
> @@ -183,11 +183,9 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
>  #ifdef ENABLE_BMAP_STATS_OPS
>  	float mark_seq_perc = 0.0, test_seq_perc = 0.0;
>  	float mark_back_perc = 0.0, test_back_perc = 0.0;
> -#endif
> -	double inuse;
>  	struct timeval now;
> +	double inuse;
>  
> -#ifdef ENABLE_BMAP_STATS_OPS
>  	if (stats->test_count) {
>  		test_seq_perc = ((float)stats->test_seq /
>  				 stats->test_count) * 100;
> @@ -201,7 +199,6 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
>  		mark_back_perc = ((float)stats->mark_back /
>  				  stats->mark_count) * 100;
>  	}
> -#endif
>  
>  	if (gettimeofday(&now, (struct timezone *) NULL) == -1) {
>  		perror("gettimeofday");
> @@ -212,6 +209,7 @@ static void ext2fs_print_bmap_statistics(ext2fs_generic_bitmap_64 bitmap)
>  		(((double) now.tv_usec) * 0.000001);
>  	inuse -= (double) stats->created.tv_sec + \
>  		(((double) stats->created.tv_usec) * 0.000001);
> +#endif /* ENABLE_BMAP_STATS_OPS */
>  
>  	fprintf(stderr, "\n[+] %s bitmap (type %d)\n", bitmap->description,
>  		stats->type);
> -- 
> 2.39.0
>