use of buffers in sprintf and snprintf
Hi again, I realised it is useful to replicate the warnings locally without relying on CRAN automatic check; instead of R(-devel) CMD check --as-cran package_version.tar.gz one can use R CMD check --configure-args="" and in my case the WARNINGS were initially given with https://www.stats.ox.ac.uk/pub/bdr/gcc9/README.txt and those specification might as well used in --configure-args above. Besst regards, Jing Hua
From: R-devel <r-devel-bounces at r-project.org> on behalf of jing hua zhao <jinghuazhao at hotmail.com>
Sent: 29 May 2019 15:49
To: r-devel at r-project.org
Subject: [Rd] use of buffers in sprintf and snprintf
Sent: 29 May 2019 15:49
To: r-devel at r-project.org
Subject: [Rd] use of buffers in sprintf and snprintf
Dear R-developers,
I am struggling with packaging with sprintf and snprintf() as the following WARNINGS from gcc 9.x,
hap_c.c:380:46: warning: ?%d? directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 127 [-Wformat-truncation=]
hap_c.c:392:46: warning: ?%d? directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 127 [-Wformat-truncation=]
Essentially, I have
#define MAX_FILENAME_LEN 128
char of1name[MAX_FILENAME_LEN],of2name[MAX_FILENAME_LEN], tempname[MAX_FILENAME_LEN];
...
snprintf(tempname,sizeof(tempname),"%s.%d", of1name, j);
It looks I could get around with
#define MAX_FILENAME_LEN 128
#define MAX_FILENAME_LEN2 256
char of1name[MAX_FILENAME_LEN],of2name[MAX_FILENAME_LEN], tempname[MAX_FILENAME_LEN2];
...
snprintf(tempname,2*sizeof(tempname)+1,"%s.%d", of1name, j)
It looks a bit waste of resources to me.
Any idea will be greatly appreciated,
Jing Hua
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