On Wed, Nov 21, 2018 at 03:53:58PM -0600, Rob Herring wrote:
> Printing to stderr as we build up the check message results in
> interleaving of messages when multiple instances of dtc are running.
> Change the message output to use an intermediate buffer for constructing
> the message and then output the message to stderr with a single fputs.
>
> While perhaps there is no guarantee that fputs will be atomic, this gets
> rid of any interleaved output that previously occurred on Linux.
>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
I can see that this would be beneficial, but..
> ---
> checks.c | 29 +++++++++++++++++++++--------
> 1 file changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/checks.c b/checks.c
> index 4d8dffd36b6e..e60940d2af86 100644
> --- a/checks.c
> +++ b/checks.c
> @@ -72,29 +72,42 @@ struct check {
> #define CHECK(nm_, fn_, d_, ...) \
> CHECK_ENTRY(nm_, fn_, d_, false, false, __VA_ARGS__)
>
> +#define MAX_MSG_LEN 1024
I really hate arbitrary buffer limits.
We are already have an xasprintf() function, so lets use that.
> +
> static inline void PRINTF(5, 6) check_msg(struct check *c, struct dt_info *dti,
> struct node *node,
> struct property *prop,
> const char *fmt, ...)
> {
> va_list ap;
> + char buffer[MAX_MSG_LEN];
> + char *str = buffer;
> + char *end = str + MAX_MSG_LEN;
>
> if (!(c->warn && (quiet < 1)) && !(c->error && (quiet < 2)))
> return;
>
> - fprintf(stderr, "%s: %s (%s): ",
> - strcmp(dti->outname, "-") ? dti->outname : "<stdout>",
> - (c->error) ? "ERROR" : "Warning", c->name);
> + str += snprintf(str, end - str, "%s: %s (%s): ",
> + strcmp(dti->outname, "-") ? dti->outname : "<stdout>",
> + (c->error) ? "ERROR" : "Warning", c->name);
> + assert(str < end);
> +
> if (node) {
> - fprintf(stderr, "%s", node->fullpath);
> if (prop)
> - fprintf(stderr, ":%s", prop->name);
> - fputs(": ", stderr);
> + str += snprintf(str, end - str, "%s:%s: ", node->fullpath, prop->name);
> + else
> + str += snprintf(str, end - str, "%s: ", node->fullpath);
> + assert(str < end);
> }
> +
> va_start(ap, fmt);
> - vfprintf(stderr, fmt, ap);
> + str += vsnprintf(str, end - str, fmt, ap);
> + assert(str < end);
> va_end(ap);
> - fprintf(stderr, "\n");
> +
> + strcpy(str, "\n");
> +
> + fputs(buffer, stderr);
> }
>
> #define FAIL(c, dti, node, ...) \
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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