2010-06-02 14:44:56

by Thomas Weber

Subject: [PATCH] scripts: confdata: Fix fwrite warning

I get for:
scripts/kconfig/confdata.c:508
scripts/kconfig/confdata.c:759
scripts/kconfig/confdata.c:760

warning: ignoring return value of ‘fwrite’, declared with attribute warn_unused_result

So check the return value and handle the error.

Signed-off-by: Thomas Weber <[email protected]>
---
scripts/kconfig/confdata.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index c4dec80..4741fea 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -505,7 +505,10 @@ int conf_write(const char *name)
while (1) {
l = strcspn(str, "\"\\");
if (l) {
- fwrite(str, l, 1, out);
+ if (fwrite(str, l, 1, out) != 1) {
+ fprintf(stderr, "write str failed\n");
+ return 1;
+ }
str += l;
}
if (!*str)
@@ -756,8 +759,14 @@ int conf_write_autoconf(void)
while (1) {
l = strcspn(str, "\"\\");
if (l) {
- fwrite(str, l, 1, out);
- fwrite(str, l, 1, out_h);
+ if (fwrite(str, l, 1, out) != 1) {
+ fprintf(stderr, "write str failed\n");
+ return 1;
+ }
+ if (fwrite(str, l, 1, out_h) != 1) {
+ fprintf(stderr, "write str failed\n");
+ return 1;
+ }
str += l;
}
if (!*str)
--
1.7.1

2010-06-04 22:16:34

by Andrew Morton

Subject: Re: [PATCH] scripts: confdata: Fix fwrite warning

On Wed, 2 Jun 2010 16:44:19 +0200
Thomas Weber <[email protected]> wrote:

> I get for:
> scripts/kconfig/confdata.c:508
> scripts/kconfig/confdata.c:759
> scripts/kconfig/confdata.c:760
>
> warning: ignoring return value of ___fwrite___, declared with attribute warn_unused_result
>
> So check the return value and handle the error.
>
> Signed-off-by: Thomas Weber <[email protected]>
> ---
> scripts/kconfig/confdata.c | 15 ++++++++++++---
> 1 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
> index c4dec80..4741fea 100644
> --- a/scripts/kconfig/confdata.c
> +++ b/scripts/kconfig/confdata.c
> @@ -505,7 +505,10 @@ int conf_write(const char *name)
> while (1) {
> l = strcspn(str, "\"\\");
> if (l) {
> - fwrite(str, l, 1, out);
> + if (fwrite(str, l, 1, out) != 1) {
> + fprintf(stderr, "write str failed\n");
> + return 1;
> + }

Missing an fclose(out), although that probably doesn't matter a lot in
practice

Also, we prefer to avoid putting `return' statements deep inside large
C functions as they can easily lead to resource leaks. Such as
forgetting to fclose(out) ;)

> str += l;
> }
> if (!*str)
> @@ -756,8 +759,14 @@ int conf_write_autoconf(void)
> while (1) {
> l = strcspn(str, "\"\\");
> if (l) {
> - fwrite(str, l, 1, out);
> - fwrite(str, l, 1, out_h);
> + if (fwrite(str, l, 1, out) != 1) {
> + fprintf(stderr, "write str failed\n");
> + return 1;
> + }
> + if (fwrite(str, l, 1, out_h) != 1) {
> + fprintf(stderr, "write str failed\n");
> + return 1;
> + }

Dittoes.

Also, this patch would be neater if it added a little helper function
around fwrite(), rather than triplicating the same code sequence.